JANUARY 1981 Vol. 6, .
$2.50. in USA/SS.95 Th Canada
• A McGra^-Hyi Publication
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HAND-HELD COMPUTERS
YOUR CHOICE-smart either way
• Over 140 software driven functions
• 82 x 24 or 82 x 20 screen format — software selectable
• High resolution 7x12 matrix characters — P-31 green phosphor
• Upper/lower case character set — plus graphics character set
• 56-key alphanumeric keyboard — plus 12-key cursor, numeric pad
• Internal editing functions — insert, delete, scroll, roll, slide, etc.
• Parallel printer I/O port
• 50 to 38,400 baud operation — programmable
• Cursor type, cursor position, print control characters, protected fields,
shift inversion, dual intensity and many other features
8212 — twelve-inch diagnonal screen or 8209 — nine-inch diagnonal screen
SOUTHWEST TECHNICAL PRODUCTS CORPORATION
219 W. RHAPSODY
SAN ANTONIO, TEXAS 78216 (512) 344-0241
Circle 338 on inquiry card.
Gromemco accepts
your challenge,
Data General
Yes, Data General, we saw your
ad.
So we realize you hope to win
over some of our computer
business.
And we can see you have reason
to be pleased about your line of
minicomputers. They are MINIs
though.
But Cromemco produces state-
of-the-art MICROcomputers.
Powerful ones.
And our micros have some
outstanding advantages.
For example, Cromemco is the
only microcomputer manufacturer
to support a broad range of
microcomputers with (a) 5-inch
WE' ISTIN0
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Announc'ins.'. MIK',
1 MBC/3,
' Data
i A/A ' board computers.
■ ■ the best computers on a
board money* an buy. Vou getup
to 64K bytes of memory, serial
rind parallel I/O lines, ^.:
■ pi ;r» from MP/OS,
our famous micro operating
system. You oven get supporting
like MP/PASCAL and
for \ ourseif.
<aa
Reproduced from the
July 31, 1980 issue of
Electronics magazine.
stition will ,
■ .-.. ■ fction I " •
double-sided, double-density floppy
disk drives and with (b) 8-inch
double-sided, double-density floppy
disk drives AS WELL AS (c) 8-inch
Winchester hard disk drives.
That means, of course, that our
customers have a wide choice of
disk storage capability.
UNEQUALLED
SOFTWARE SUPPORT
OK. That was one point.
Here's another: our stunning
selection of software support.
Cromemco is the only micro
manufacturer to produce both
single-user and multi-user multi-
tasking computers with software
like this:
SYSTEM SOFTWARE
CDOS (a CP/M-like operating
system)
CROMIX (a UNIX-like operating
system)
RPG-II (IBM-compatible)
COBOL
BASIC
FORTRAN IV
RATFOR
LISP
C
Macro Assembler
APPLICATION SOFTWARE
Word Processing System
Data-Base Management
General Ledger
Accounts Receivable
Accounts Payable
Inventory
All of this is available now with
more coming all the time.
So there you are, D.G.
You can see why we know our
microcomputers will stand the test.
Cromemco eagerly accepts the
challenge.
Cromemco logo on
computer board shown
in original ad
Circle 1 on inquiry card.
Cromemco
incorporated
Tomorrow's Computers Today
280 BERNARDO AVE. MOUNTAIN VIEW, CA 94043
(415) 964-7400 • TWX 910-379-6988
BYTE January 1981
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Management Information Display
Ultrasonic heart sector scan
High-resolution display with alphanumeric^
Get the professional color
display that has
BASIC/FORTRAN simplicity
LOW-PRICED, TOO
Here's a color display that has
everything: professional-level resolution,
enormous color range, easy software,
NTSC conformance, and low price.
Basically, this new Cromemco Model
SDI* is a two-board interface that plugs
into any Cromemco computer.
The SDI then maps computer display
memory content onto a convenient color
monitor to give high-quality, high-
resolution displays (756 H x 482 V pixels).
When we say the SDI results in a high-
quality professional display, we mean you
can't get higher resolution than this
system offers in an NTSC-conforming
display.
The resolution surpasses that of a color
TV picture.
BASIC/FORTRAN programming
Besides its high resolution and low
price, the new SDI lets you control with
optional Cromemco software packages
that use simple BASIC- and FORTRAN-
like commands.
Pick any of 16 colors (from a
4096-color palette) with instructions like
DEFCLR (c, R, C, B). Or obtain a circle of
specified size, location, and color with
XCIRC (x, y, r, c).
•U.S. Pat. No. 4121283
Model SDI High-Resolution Color
Graphics Interface
HIGH RESOLUTION
The SDI's high resolution gives a
professional-quality display that strictly
meets NTSC requirements. You get 756
pixels on every visible line of the NTSC
standard display of 482 image lines. Ver-
tical line spacing is 1 pixel.
To achieve the high-quality display, a
separate output signal is produced for
each of the three component colors (red,
green, blue). This yields a sharper image
than is possible using an NTSC-composite
video signal and color TV set. Full image
quality is readily realized with our high-
quality RGB Monitor or any conventional
red/green/blue monitor common in TV
work.
Model SDI plugs into Z-2H 11-megabyte
hard disk computer or any Cromemco
computer
DISPLAY MEMORY
Along with the SDI we also offer an
optional fast and novel two-port memory
that gives independent high-speed access
to the computer memory. The two-port
memory stores one full display, permit-
ting fast computer operation even during
display.
CONTACT YOUR REP NOW
The Model SDI has been used in scien-
tific work, engineering, business, TV,
color graphics, and other areas. It's a
good example of how Cromemco keeps
computers in the field up to date, since it
turns any Cromemco computer into an
up-to-date color display computer.
The SDI has still more features that
you should be informed about. So contact
your Cromemco representative now and
see all that the SDI will do for you.
Circle 1 on inquiry card.
G
Cromemco
incorporated
280 BERNARDO AVE., MOUNTAIN VIEW, CA 94040 • (415)964-7400
Tomorrow's computers today
In The Queue
Volume 6, Number 1
January 1981
Features
1 8 An Introduction to Atari Graphics by
Chris Crawford and Lane Winner / Learning to use
the Atari display list can help to unleash the full power
of Atari's custom LSI video integrated circuits.
34 The Panasonic and Quasar Hand-Held
Computers: Beginning a New Generation of
Consumer Computers by Gregg Williams and Rick
Meyer / This full-function computer fits in your hand
and weighs 14 ounces.
4"0 Electromagnetic Interference by Steve
Ciarcia / Interfering electrical noise must be dealt with
according to its mode of transmission.
7 2 The NEC PC-8001 : A New Japanese
Personal Computer by Michael Keith and C P
Kocher / This popular Japanese personal computer may
soon be sold in the United States.
1 48 Generating Bar Code In the Hewlett-
Packard Format by Thomas McNeal / Bar code pro-
vides a cheap, easily reproduced, mass-storage medium
that encourages the publication of software.
226 The Picture-Perfect Apple by Phil Roybal
This driver software allows your printer to transcribe the
high-resolution graphics of the Apple II personal com-
puter.
Micrograph, Part 3: Software and
Operation by E Grady Booch / Part 3 concludes this
series with a description of Micrograph's powerful soft-
ware and instruction-set usage.
318 Whose BASIC Does What? by Teri Li
Knowing the differences between the six most popular
BASICS is essential.
Reviews
94 The Sinclair Research ZX80 by John C
McCallum
1 18 The HP-41C: A Literate Calculator?
by Brian P Hayes
208 The Newest Sargon — 2.5 by John
Martellaro
216 The SwTPC 6809 Microcomputer
System by Tom Harmon
Nucleus
6 Editorial: Hand-Held Computers
10, 292, 314 BYTE's Bits
12 Letters
90 Technical Forum: SC/MP
Instruction-Set Summary
104 Education Forum: Multi-Micro
Learning Environments
1 42 Desk-Top Wonders
182 Systems Notes
188 Languages Forum: A Bug in
BASIC
200 BYTELINES
282 Ask BYTE
294 Software Received
296, 298 BYTE's Bugs
298 Books Received
300 Book Reviews
304 Event Queue
312 Clubs and Newsletters
328, 334 Programming Quickies
336 What's New?
382 Unclassified Ads
383 BOMB, BOMB Results
384 Reader Service
BITE
Page 34
Page 48
Page 72
Page 104
January 1981 © BYTE Publications Inc 3
lim
Editor in Chief
Christopher Morgan
Technical Editors
Richard S Shuford; Gregg Williams;
Curtis P Feigel; Harold Nelson;
Stan Miastkowski; Kevin Cohan; Bruce Roberts;
Charles Freiberg, New Products; Steve Ciarcia,
Mark Dahmke. Consulting Editors
Copy Editors
David W Hayward, Chief; Faith Hanson;
Warren Williamson; Robin M Moss;
Anthony J Lockwood
Assistants
Faith Ferry; Debe Wheeler;
Karen A Cilley; Jon Swanson
Production
Nancy Estle. Director; Christine Dixon,
Asst Director; Wai Chiu Li;
Holly Carmen LaBossiere; Deborah Porter;
Sherry McCarthy, Chief Typographer;
Debi Fredericks; Donna Sweeney;
Valerie Horn
Advertising
Thomas Harvey, Director; Ruth M Walsh;
Marion Gagnon; Barbara J Greene;
Rob Hannings
Circulation
Gregory Spitzfaden, Manager:
Andrew Jackson, Asst Manager;
Agnes E Perry; Barbara Varnum;
Louise Menegus; Melanie Bertoni,
Dealer Sales
Marketing
Jill E Callihan, Special Projects;
Laura Hanson
Controller's Office
Daniel Rodrigues, Controller; Mary E Fluhr,
Asst Controller; Karen Burgess; Jeanne Cilley
Traffic
Mark Sandagata; N Scott Gagnon
Receptionist
Jacqueline Earnshaw
Publishers
Virginia Londoner; Gordon R Williamson;
John E Hayes, Associate Publisher;
Cheryl A Hurd, Publisher's Assistant
Officers of McGraw-Hill Publications Com-
pany: Paul F McPherson, President; Executive
Vice Presidents: James E Boddorf, Gene W
Simpson; Group Vice President: Daniel A
McMillan: Senior Vice President-Editorial: Ralph
R Schulz; Vice Presidents: Kemp Anderson,
Business Systems Development; Stephen C
Croft, Manufacturing; Robert B Doll, Circulation;
James E Hackett, Controller; William H Ham-
mond, Communications; Eric B Herr, Planning
and Development; John W Patten, Sales;
Edward E Schirmer, International,
Officers of the Corporation: Harold W
McGraw Jr, President, Chief Executive Officer
and Chairman of the Board; Robert F Landes,
Senior Vice President and Secretary; Ralph J
Webb, Treasurer.
..■..■- ;-V-V-^
In This Issue
This month's cover photograph by Ed Crabtree highlights
three examples of a new phenomenon in the personal com-
puter field: the HHC (hand-held computer). Shown are (from
top to bottom): the Panasonic HHC; the Quasar HHC; and the
Radio Shack HHC. All three units are discussed in this issue.
Other articles this month describe two other miniature com-
puters: the Sinclair ZX80 and the Hewlett-Packard HP-41C.
Elsewhere in this issue, Steve Ciarcia describes electro-
magnetic interference; we describe some of the exciting capabil-
ities of Atari graphics; and We review an intriguing new
Japanese computer: the NEC 8001; plus a new regular section
of hardware and software reviews.
BYTE is published monthly by BYTE Publications Inc. 70 Main St, Peterborough NH 03458, a wholly-owned
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Apopka FL 32703
January 1981 © BYTE Publications Inc.
■ COLOR
GRAPHICS
■ IT'S HERE
8455-D Tyco Road
Vienna, Virginia 22180
(703) 827-0888
TWX: 710-831-9087
OEM/Dealer inquiries invited
Circle 2 on inquiry card.
Circle 3 on inquiry card.
UCSD
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NOW AVAILABLE
Operating System
Compilers
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Business and
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Popular Micros
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Editorial
The Hand-Held Computer
Chris Morgan, Editor-in-Chief
There's a new trend in personal computing today — the HHC (hand-held
computer). For years computer aficionados have dreamed of a computer small
enough to fit in one's pocket, yet powerful enough to do the sorts of jobs that
full-size microcomputers do today.
Amazingly enough, the dream is coming true. There are now no less than
four models (the Radio Shack/Sharp, the Panasonic/Quasar, the Hewlett-
Packard HP-41C, and the Sinclair ZX80) that fall roughly into the ultra-small
computer category. One might quibble with calling the HP-41C a "computer"
rather than a programmable calculator, but it has all the necessary elements to
qualify: memory, processor, I/O (input/output), and a full line of peripherals.
Each of these computers is discussed in this issue.
Among the new crop of HHCs, the Panasonic /Quasar (reviewed on page
34) is perhaps the most impressive in terms of engineering innovations; it
sports some features that many full-size personal computers don't have, such
as the ability to run for long periods from battery power alone — an impressive
achievement when you realize that the unit uses, not a CMOS (complementary
metal-oxide semiconductor) processor, but a standard 6502! It also has such
niceties as user-definable keys, a built-in real-time clock, uninterruptible
storage of user programs, and the ability to produce color images on a color
television (with the addition of an optional interface unit).
The Radio Shack HHC has its own attractions, including its (relatively) low
price of $250 and its surprisingly complete BASIC interpreter. The first time I
saw the Radio Shack unit was at the West Coast Computer Faire last spring,
where it was being shown in its original form from Sharp. I was intrigued, but
I quickly concluded it was just a passing fad. Not until I used the computer at
length did I begin to realize its potential. Here was a machine capable of run-
ning complex BASIC programs — and it was truly portable! (I have to admit
that a lot of the fun connected with these units is taking them out of one's
pocket and showing them to noncomputer people.)
What about the practical considerations of typing programs on such a tiny
keyboard? Well, at first it felt awkward, but I quickly adjusted to it. (The
Panasonic/Quasar is a bit better in this regard, because the keys are spaced
more widely apart.)
Speaking of attractive prices, the Sinclair ZX80, for $200 or so, has its own
appeal. Strictly speaking, it's not a hand-held computer because it uses a
separate AC adapter. Still, it's tiny and can be easily transported. It has
become an overnight sensation in England. As our review on page 94 points
out, the ZX80 has some bad characteristics, such as screen blankout during ex-
ecution of programs. Even so, a student or other beginner in computer pro-
gramming could learn a lot with this machine in conjunction with its introduc-
tory BASIC book (included in the purchase price), which seems to be very
good.
Why all the sudden interest in miniaturization? In part, it's the logical
culmination of the never-ending battle to put more and more capability into
less and less space. Combine that with the recent Japanese trend toward
miniature hi-fi components, and you begin to see the driving forces involved.
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For reliable data storage,
I recommend systems with
Shugart disk drives!
"" Tom Knight, President—
Nycom, Los Altos, California
"The last thing you need when you put
your personal computer or small business
system to work is a disk drive that you
can't rely on. If the drive quits, your
system is out of business!'
That's why more and more manu-
facturers and dealers depend on Shugart
disk drives for reliable data storage. These
professionals don't want disk drive prob-
lems any more than you do. Shugart has a
large family of drives, too— in all sizes and
capacities to suit your system storage
needs. For the smaller system, the original
5'/4-inch Minifloppy '* stores 250 to 500
kilobytes (single or double-sided)— thatfs
about 50 to 100 pages of printed material.
Our single and double-sided 8-inch
floppys store 800 to 1600 kilobytes. And
for systems that need a larger data base,
our 8-inch or 14-inch fixed disk drives
store from 5 to 58 megabytes. No other
manufacturer offers such a wide variety of
disk storage for personal computer and
small business systems.
Word processing, general business,
accounting— big system or small, you can
rely on Shugart drives. We're known as the
Headstrong company for good reason.
We're Headstrong about reliability, quality,
and value. Ask your dealer. He knows us.
TM— Minifloppy is a trademark of Shugart Associates.
Rely on the
Headstrong Company.
%AShugart
475 Oakmead Parkway, Sunnyvale, California 94086
Editorial
The Japanese are going to continue to assert themselves in
the personal-computer market with both large and small
personal computers. Seiko is rumored to be working on a
hand-held computer to be released later this year — and
that will be just the beginning, our sources tell us. In-
terestingly, Commodore had until recently been planning
to market a hand-held computer, but abandoned the plan
to concentrate on the new VIC 20 color computer. (We
saw this $299 (!) unit recently, and will be reporting on it
soon. The color quality is remarkable for the price.) Look
for additional entries into the hand-held-computer
market from US companies later this year.
Miniature Intelligent Terminals
One of the most important trends now going on behind
the scenes is the pocket-size intelligent terminal being
developed by Bob Doyle and Jeff Rochliss. The unit, call-
ed the Microterminal, will be battery operated and the
size of a pocket calculator. It will contain an intelligent
terminal with single-line liquid-crystal display, a modem,
a repertory dialer, and a printer. With this unit (which
will probably retail for under $300), the user can plug in-
to any modular phone jack and access data bases all
around the country, pay bills, get news, send and receive
messages, and so on. The implications of this technology
are enormous. We'll have a full report on this unit in an
upcoming issue of BYTE.
Our New Look
You may have already noticed some of the layout and
design changes in this issue of BYTE. It's all part of our
continuing effort to make the magazine easier to read and
more useful to our readers. The major change is the addi-
tion of a new section in the magazine devoted to hard-
ware and software reviews. This is in response to our
reader surveys that show your increasing interest in the
many new products flooding the market. This new sec-
tion will give you a variety of unbiased, detailed reviews
each month.
We have redesigned the table-of-contents, or "In The
Queue," page to make room for the additional new mate-
rial. We have not decreased the number of articles. They
will continue to be the mainstay of BYTE, as will the
many popular features in the "Nucleus" section. We have
Articles Policy
BYTE is continually seeking quality manuscripts written by indi-
viduals who are applying personal computer systems, designing
such systems, or who have knowledge which will prove useful
to our readers. For a more formal description of procedures and
requirements, potential authors should send a large (9 by 1 2 inch,
30.5 by 22.8 cm), self-addressed envelope, with 28 cents US
postage affixed, to BYTE Author's Guide, POB 372, Hancock NH
03449.
Articles which are accepted are purchased with a rate of up to
S50 per magazine page, based on technical quality and suitability
for BYTE's readership. Each month, the authors of the two
leading articles in the reader poll (BYTE's Ongoing Monitor Box or
"BOMB") are presented with bonus checks of $100 and S50.
Unsolicited materials should be accompanied by full name and
address, as well as return postage.
PASCAL/Z - Q.E.D.
Ithaca Intersystems PASCAL/Z is the most powerful CP/M™
compatible Z-80™ Pascal compiler ever . . . and here's why:
PASCAL/Z generates true Z-80 native code - ROMable
and re-entrant — 5-1 OX faster than P-code interpreters;
permits separate compilation; supports Direct File Access
and variable length STRINGs; utilizes fast one-pass recursive
descent organization; the macro-assembler generates
relocatable object modules; and much, much more.
Complete package includes compiler, macro-assembler,
linker/loader and source for the full library on one disk; with
free copy of Jensen/Wirth book and complete documenta-
tion. Only $395.00.
IT'S DEMONSTRABLE!
Don't just take our word for it. Ask for a demonstration of
these features and more today at Computerland® and other
full-service computer stores.
Ithaca Intersystems Inc., 1650 Hanshaw Road
P.O. Box 91, Ithaca, N.Y. 14850. Phone (607) 257-0190
Computerland is a registered trademark of Computerland Corporation.
CP/M and Z-80 are trademarks of Digital Research Corp. and Zilog, inc. respectively
PASCAL/Z and InterSystems are trademarks of Ithaca Intersystems Inc.
^TM
8 January 1981 © BYTE Publications Inc
Circle 4 on inquiry card.
Ithaca Intersystems Inc.
Micros for bigger ideas.
Outside of the garden
you need a computer that can grow.
For the average garden-variety home and hobby operation,
a high quality personal computer is a real temptation. But
let's face it: in the world of business, engineering and
scientific applications you need a system that can keep up
with bigger ideas.
Bigger ideas today mean the power and flexibility to
move the micro up to and beyond the level of yesterday's
minis. More memory to hold bigger data bases. More
flexibility to handle a variety of data entry devices. More
programming and computing power for numbercrunching
and applications development. And easy upgrade to 16 bit
operation when you need it.
Intersystems has that, and more. The power and flexibility
of the versatile S- 100 bus, with 20 slots of expandability for
up to 16 individually-addressable DMA devices and up to 1
Megabyte of memory, fully accessible to all users via our
unique memory management system. Plus reliable
Intersystems design and manufacture, and the support of
our PASCAL/Z T "...the most powerful Z-80 ,M compiler ever.
For really serious computing, our front panel provides a
powerful diagnostic tool for debugging or development.
Combined with a scope, it allows you to look at any location
in the circuitry, set breakpoints, trigger and view one-shot
events, and many other activities usually possible only with
expensive logic analyzers. No wonder it's fast becoming the
tool of choice for repair technicians and custom hardware
designers.
Intersystems Series II is the most complete line of fully
IEEE 696 compatible S-100 boards.. .easily upgradeable to
our MPU 8000™ or other 16 bit S-100 CPU's as they become
available.. .so you're never locked out of rapid expansion, or
locked into obsolescence, by dependency on a proprietary
product line.
So if you've left those garden-variety applications behind,
come to Intersystems and get a system that will grow as big
as your next idea. Get it from the people who know small
computers.. .your Computerland store... or other fine full
service computer dealers.
Ithaca Intersystems Inc., 1650 Hanshaw Road
P.O. Box 91, Ithaca, N.Y. 14850.
Phone (607) 257-0190 TWX: 510 255 4346.
Z-80 is a Iradernark of Zilog. Inc
PASCAL /Z MPU 8000 and InterSyslems are trademarks of Ithaca iniersysiems. Inc
OODfeO
Intersyste
Micros for bigger ideas.
Circle 5 on inquiry card.
BYTE January 1981
Editoriai.
eliminated the "Background" and "Foreground" designa-
tions because we have encountered many good articles
that don't fit either category. We invite your comments,
pro or con.B
The November Cover
Much mail has come in requesting further informa- .
Hon on our November cover. It's actually a "still, " one
of many extraordinary images from "The Works, " a
90-minute fully computer-generated feature film. This
science-fiction film is currently in production at the
Computer Graphics Laboratory of the New York In-
stitute of Technology in Old Westbury, Long Island,
New York. The laboratory staff consists of a large
number of exceptionally talented artists and engineers
with extensive backgrounds in film-making, computer
science, mathematics, and digital audio.
The digital-animation systems are state-of-the-art,
using many Digital Equipment Corporation computers
that have been interfaced to frame buffers. The con-
tents of the frame buffers are recorded onto 35 mm
movie film with high precision. The film will be in pro-
duction for the next two years, fudging from what I
have seen, it should be sensational. We thank the New
York Institute of Technology for allowing us to see
their work in progress. We hope to report on their
graphics activities sometime soon in BYTE.
FLOPPY DISK FACTORY DIRECT FLOPPY DISK FACTO
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• Buy factory direct from the manufacturer of floppy disks
sold exclusively under other well-known brand names.
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which are 1 00°/o certified for 40 track, dual side, double
density and all other standard applications.
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BYTE's Bits
You Can Bank On It
Electronic home banking
is a reality in Knoxville,
Tennessee. The Express In-
formation bank-at-home ser-
vice is a joint venture of
United American Service
Corporation, Radio Shack,
and CompuServe. The
United American Bank in
Knoxville was selected as the
first bank to use and market
the service to its customers.
For a $15 to $25 per month
fee, United American Bank
customers can use a TRS-80
Color Computer to access
news and financial advisory
services, pay bills, receive
checking-account informa-
tion, use a bookkeeping ser-
vice, and to apply for loans.
The CompuServe network
provides the bank-at-home
customers with a shopping
list of national, interna-
tional, and financial news,
plus the latest stock quota-
tions and commodities infor-
mation. The United Amer-
ican Bank plans to add its
own bank news and daily
information on savings and
deposit rates. Customers of
the bank are issued a secur-
ity pack and certificates that
can be redeemed at Radio
Shack outlets. In addition to
the financial services, cus-
tomers can use the TRS-80
Color Computer for home
entertainment, education,
security, message services,
electronic filing, and as an
electronic mail service. For
details, contact Tom Sud-
man, c/o the United
American Bank, in Knox-
ville, Tennesee, (615)
971-2121; David Beckerman,
c/o the Tandy Corporation,
Ft Worth, Texas, (817)
390-3273; or Richard Baker,
c/o CompuServe, Colum-
bus, Ohio, (614) 457-8600. ■
10 January 1981 © BYTE Publications Inc
Circle 6 on Inquiry card.
Circle 7 on inquiry card.
If you
^interface****
and you w ^J e a board for
y Ul
Serialtot<*K5
axinvum
coxnpat
For ex
^P le T \2rninal to get 8 ° Se-sViaring
services, « * * ftware program d
7S ^ovides a P°*f ^teany
ware prov > t ne ed tow
«'""", ..^erfacc
inC
iudes i
software ^-^-^^ p^
orAy one aPPj^ace.
raUelint
Two
.teriacetbeAPP^
Maybe we can
save you a call.
Many people have called with the
same questions about the AIO.
We'll answer those and a few more here.
Oa Does the AIO have hardware handshaking?
A: Yes. The serial port accommodates 3 types— RTS,
CTS, and DCD/The parallel port handles ACK, ACK,
BSY, STB, and STB.
Cb What equipment can be used with the AIO?
A: A partial list of devices that have actually been tested
with the AIO includes: IDS 440 Paper Tiger, Centronics
779, Qume Sprint 5, NEC Spinwriter, Comprint, Heathkit
H14, IDS 125, IDS 225, Hazeltine 1500, Lear Siegler
ADM-3, DTC 300, AJ 841.
Q: Does the AIO work with Pascal ?
A: Yes. The current AIO serial firmware works great
with Pascal. If you want to run the parallel port, or both
the serial and parallel ports with Pascal, order our
"Pascal Patcher Disk'.'
GL What kind of firmware option is available for
the parallel interface?
A: Two PROM's that the user installs on the AIO card
in place of the Serial Firmware PROM's provide:
Variable margins, Variable page length, Variable
indentations, and Auto-line-feed on carriage
return.
GU How do I interface my new printer to my Apple
using my AIO card?
A: Interconnection diagrams for many popular
printers and other devices are contained in the
AIO Manual. If your printer is not mentioned,
please contact SSM's Technical Support Dept.
and they will help you with the proper
connections.
GU I want to use my Apple as a dumb terminal
with a modem on a timesharing service like
The Source. Can I do that with the AIO?
A: Yes. A "Dumb Terminal Routine" is listed
in the AIO Manual. It provides for full and
half duplex, and also checks for presence
of a carrier.
«iyW=: d , ?*Sit°»»"f.
to both »
h*>£rZ*»*ZS:£Z!*f,
going
i compete
alPRO^^'soHware'Usungs.
tac\udmgj^ rROr ^tact
cables, an ^ m q at? aUO n.
us
more
gSffl
...rw^on Drive
2190
San
(408)
Paragon
Jose
946
California
-7400
95131
•Apple
TMoSAW te
Cotnp""* 3 '
Qc What length cables are provided?
A: For the serial port, a 12 inch ribbon cable
with a DB-25 socket on the user end
is supplied. For the parallel port, a 72 inch
ribbon cable with an unterminated user
end is provided. Other cables are available
on special volume orders.
The AIO is just one of several boards
for the Apple that SSM will be introducing
over the next year. We are also
receptive to developing products to
meet special OEM requirements.
So please contact us if you have
a need and there is nothing available
to meet it.
SSM Microcomputer Products
2190 Paragon Drive
San Jose, California 95131
(408) 946-7400
Letters
Send + More = Code
I certainly enjoyed Peter Frey's article
"Machine Problem Solving, Part 2" (see
the October 1980 BYTE, page 266),
which concerned directed search using
cryptarithmetic. Unfortunately the pro-
gram does not do quite all that it is
advertised to do, probably due to omis-
sions in the press copy.
For example, on page 268 Mr Frey
stated, "It is also necessary to prepare
the machine with the knowledge that
blank spaces which precede letters in the
first two rows should be treated as
zeros." Program lines 270 and 280,
however, can never be executed because
of the branch instruction in line 210,
which bypasses lines 270 and 280 com-
pletely. As a result, problems such as
"SPEND + MORE = MONEY" cannot be
solved, and an error message is gen-
erated. Changing the branch instructions
at line 210 to cause a jump to line 270,
instead of line 300, eliminates this prob-
lem, as long as the short word is not
more than one letter less than the other
word.
A second malfunction occurs in prob-
lems of the "SEND + MORE = MONEY"
type: when the sum word contains one
more letter than the addends and also is
a unique letter (such as in "SEND
+ MORE = HONEY"). The program
recognizes the patterns and alters the ar-
ray correctly, but the value for that let-
ter is not displayed on the screen. A
short statement immediately after a suc-
cessful pattern search, such as:
415 PRINT @ 762 + 6*NL, 1
seems to correct this error.
K W Butcher
Canton ME 04221
Mr Butcher's comments are correct.
We appreciate the feedback.... CM
Introducing
THE
BcnchmarK
WORD
PROCESSING
SYSTEM
THE BENCHMARK software system sets new standards in word processing. First, it
can be delivered to run on the CP/M or the North Star DOS, so there may be no need to
buy a special operating system. Second, it has all the features of systems costing
thousands of dollars more. Third, the price is as low as, or lower than, most word
processing systems.
Anyone can learn to run and use THE BENCHMARK in one day of self training.
Completely self-prompting in English. THE BENCHMARK is a full capability word
processor, has been thoroughly tested in an office environment and proved to meet the
needs of the most sophisticated user.
• Multi-operating system • Overtype - erases, corrects
• Changes terminal drivers • Variable, electronic decimal tab
• Customized to utilize all the • Screen menus simplify operation
features of terminal & printer • Block move and get
^^ ^% Ck Ck p' us tax
ONLY 9"l9 9 where applicable
THE BENCHMARK is distributed exclusively by RS.B Computer Systems. Dealer
inquiries are invited.
ftp Computer
1954 E. University
Systems
Tempe, Arizona 85281
1-800-528-7385 AZ-602-968-7101
THE BENCHMARK is a trademark of Metasoft Corporation
Software for the Altos
I read with great interest Mark
Dahmke's article in the November 1980
BYTE concerning the Altos machine.
(See "The Altos ACS 8000 Single-Board
Computer," page 158.) I agree with Mr
Dahmke's assessment of the Altos as a
well-designed and reliable machine. I
was especially interested, however, in
his comments on the available software
for the Altos.
I represent Avtek Inc, the software
house that wrote APULIB and the bisyn-
chronous and asynchronous communica-
tions packages for the Altos machine
mentioned in the article. The software
picture for the Altos is not really as grim
as the article makes it appear. Avtek has
written many other software packages
for the Altos. Among them:
• OPRA— A enhancement to the CP/M
operating system. It increases disk-
storage capacity by 40%, disk-I/O (in-
put/output) speed by a factor of 2, it
supports a type-ahead buffer, and it pro-
vides for easy mixed-mode operation.
• Communications Packages — In addi-
tion to the full IBM 2780/3780 bisyn-
chronous and asynchronous packages I
already mentioned, there is a syn-
chronous communications package for
Altos-to-Altos use. Incidentally, the
price of the bisync package has been
lowered to $495.
• GRAFLIB—A two- and three-
dimensional graphics-subroutine library
for use with the Altos and a modified
Lear-Siegler ADM-3A terminal (512 by
256 resolution), a Diablo 1650 printer,
and a multicolor plotter.
• Graphics and Scientific System — A
complete system for the Altos and the
modified ADM-3A that contains Avtek's
own screen-oriented editor, a scientific-
paper typesetting package, and many
stand-alone and subroutine packages for
graphics and for the solution of special-
ized scientific and mathematical prob-
lems. This system also supports the
Diablo 1650 printer, for graphics and
manuscripts, etc, and multicolor plot-
ters.
In addition to those packages, Avtek
has plans for several others, including a
financial modeling package. I think that
the software that Avtek supplies makes
the Altos a very versatile and useful
machine. In fact, it turns the Altos into
a system.
John C Theys
President
Advanced Computational Technology Inc
30 Side Cut Rd
West Redding CT 06896
12 January 1981 © BYTE Publications Inc
Circle 8 on Inquiry card.
Circle 9 on inquiry card.
Edison had over
1,800 patents in
his name, but
you can be just as inventive
with an Apple.
Apple is the company with the brightest ideas in
hardware and software and the best support — so you can
be as creative with a personal computer system as Edison
was with the incandescent bulb.
How Apple grows with you.
With Apple's reliable product family, the possibilities of
creating your own system are endless. Have expansion capa-
bilities of 4 or 8 accessory slots with your choice of system.
Expand memory to 64K bytes or 128K bytes. Add an
A to D conversion board. Plug into time sharing, news and
electronic mail services. Use an IEEE 488 bus to monitor
lab instruments. Add 4 or 6 disk drives — the 5 "A" 143K
bytes, high-speed, low-cost drive that's the most popular
on the market.
Apple speaks many languages.
Since more than 100 companies create software for
Apple, you'll have the most extensive library in the personal
computer world. Want to write your own programs?
Apple is fluent in BASIC, Pascal, FORTRAN, PILOT and
6502 assembly language.
There's even a series of utility programs called the
DOS Tool Kit that not only lets you design high-resolution
graphic displays, but lets you work wonders with
creative animation.
More illuminating experiences in store.
You won't want to miss all the Apple products being
introduced at your computer store all the time. Don't let
history pass you by. Visit your nearest
Apple dealer or call 800-538-9696.
In California, 800-662-9238. Or write:
Apple Computer, 10260 Bandley Drive,
Cupertino, CA 95014.
tippkz computer inc.
Circle 10 on inquiry card.
U.S.A.
ARISTO/POLKS
314 5th Ave. (32 ST) N.Y.C.. N.Y. 10001
Telephone: (212) 279-9034
DIP 81 _^^Mrt^tt Impact Printer
A quality printer, designed for
continuous printing duty cycle, giving
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The small, quiet, light, highly depend-
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an extensive range of features
The new 150 CPS full size carriage, dot
matrix printer. Bidirectional and logic
seeking, taking up to 15" paper.
&w
NEW SUPERBOARD 3 . . . . S 279
CHALLENGER C1P8K . . . S 479
C1PS" FLOPPY 20K . . . . S 1279
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C4P FLOPPY 24K 5" . . . . $1799
COLOR-DUALS" FLOPPY C8P . $ 2995
C-3 48K DUAL-FLOPPY 8" . . $ 3995
C-3+ 23 MEG HARD DISK . . $10995
PLUS ALL SOFTWARE AND PERIPHERALS
AH European trade enquiries to:
NORTH AMBER LTD
Great Oak House, Esher.Surrey, England
KT10 9BR Telephone: 0372 62071
V
Letters.
68000 At Last?
In looking over a recent issue of
BYTE, I came across a section titled
"BYTELINES" that contained references
to the MC68000. (See "68000, Where
Art Thou?" September 1980 BYTE, page
164.) The message that I got from
reading the commentary was that the
MC68000 is still in the experimental
stage. This is untrue I All unreserved op
codes have been defined, and the in-
struction set has been frozen since
January 1980. The second point is that
we have been shipping the 68000 in large
quantities for some time now. We have
no problem committing to delivery on
large-production quantities.
Since those comments were based on
customer inputs, I can understand some
confusion. I hope that this letter will
help to resolve it.
Steve Sparks
Manager
Marketing and Applications
Motorola Inc
3501 Ed Bluestein Blvd
Austin TX 78721
Sol Libes Replies:
The column in question was written
some time ago. At that time, two OEMs
(original equipment manufacturers) that
wanted to use the 68000 reported to me
that they were still not able to go into
production on planned products because
Motorola still had not completed the
68000's design and would not fill pro-
duction orders. In other words, the facts
as I reported them were true at the time.
I understand that Motorola is now ship-
ping production quantities.
A System Note
One problem with OSI (Ohio Scien-
tific) systems (most notably the C-2) has
been the inability to utilize the 6502 IRQ
and NMI commands from a BASIC pro-
gram, via USR routines. The problem
originates from the fact that the reset
vectors for these commands, contained
in the system's ROM (read-only mem-
ory), point to an area of memory that is
heavily used by BASIC (ie: hexadecimal
addresses 01XX). Thus, it is impossible
to field either of these interrupts because
BASIC rapidly destroys any service
routine.
My colleagues and I have proposed to
OSI that new firmware be produced,
identical to the old one in all respects
but for the IRQ and NMI reset vectors.
These would be changed to point to a
part of memory that is "stable" (eg:
hexadecimal addresses D0XX or E0XX).
However, for such a new device to be
produced, it must be financially feasible
to do so (the cost to be in the $0.25 to
$0.50 range). So, we would like to ask
all interested OSI users to drop a quick
note to Ohio Scientific expressing
interest:
Ohio Scientific Computers
Attn: Customer Relations
1333 S Chillicothe Rd
Aurora OH 44202
If enough replies are received, all of us
may well see a new monitor device.
Thanks so much!
Shaun D Black
University of Michigan
Department of Biological Chemistry
5440 Medical Sciences I
Ann Arbor MI 48109
Intercepting Raster
I very much enjoyed John Beetem's ar-
ticle entitled "Vector Graphics for Raster
Displays." (See the October 1980 BYTE,
page 286.) To say the least, I found it a
unique method. However, I must take
exception to one statement that was
made regarding techniques for plotting
vectors.
In referring to the slope-intercept and
trigonometric methods of calculation,
Mr Beetem states, "None of these is very
good for a small computer, because
many slow multiplications and divisions
are needed." This is simply not true, at
least not in the case of the slope-inter-
cept method. (Note: In the following
discussion, for simplicity, it will be
assumed that the X length is greater than
the Y length. If this is not the case, the
X and Y values should be swapped; the
program under discussion handles the
data in approximately this way.)
The formula used in the common im-
plementation of the slope-intercept
method is Y=MX + B, where
M = (Y2-Yl)/(X2-Xl) and
B = Y2-(X2XM). In other words, the
value that represents the slope of the line
is multiplied by the given X value, then
added to the origin (offset) to determine
the Y position. To plot a vector, one
would normally step through the X
values and calculate matching Y coor-
dinates from one end of the vector to
the other.
In examining the formula, it should be
obvious that if X is stepped by a con-
stant amount, then Y will also increase
by some constant value. To reduce the
algorithm to its simplest form, it is best
to increment X by 1 (because, by defini-
tion, we cannot plot any fractional
points). One can, therefore, find the Y
increment value simply by dividing the
Y length by the X length.
How complicated is the actual algo-
rithm? Not very. Unitek Ltd is currently
developing a high-level graphics package
14 January 1981 © BYTE Publications Inc
TRS-80* Model I Computer Owners . . .
Double-density storage.
It's really here!
Here at Percom. And your authorized Percom dealers.
And double-density storage is here in a big way. Because now
you can choose from three different levels of mini-disk systems —
all double-density rated.
And get the storage that precisely meets your application
needs.
Not to mention the service and quality that's made Percom the
industry leader.
Although rated for double-density operation, all
levels of Percom drives work equally well in single-
density applications.
You can operate these drives in ordinary single-
density format using TRSDOS* Percom OS-80™
or any other single-density operating system.
Or, you can add a Percom DOUBLER™ to your
Tandy Expansion Interface and store data and
programs in either single- or double-density
format.
Under double-density operation, you can store
as much as 350 Kbytes of formatted data — de-
pending on the drive model — on one side of a
five-inch minidiskette. That's four times the
capacity of standard 35-track Model I mini-
disks, almost 100 Kbytes more than the capacity
of the eight-inch IBM 3740 format!
Available in 1-, 2- and 3-drive configurations in
all three model lines, Percom burned-in, fully-
tested drives start at only $399.
TFD-40™ Drives
TFD-40 Drives store 180 Kbytes (double-density) or
102 Kbytes (single-density) of formatted data on one
side of a 40-track minidiskette. Although economical-
ly priced, TFD-40 drives receive the same full Percom
quality control measures as TFD-100 and TFD-200
drives.
TFD-100™ Drives
TFD-100 drives are "flippy" drives. You store twice
the data per minidiskette by using both sides of the
disk. TFD-100 drives store 180 Kbytes (double-
density) or 102 Kbytes (single-density) per side.
Under double-density operation, you can store a 70-
page document on one minidiskette.
TFD-200™ Drives
TFD-200 drives store 350 Kbytes (double-density) or
197 Kbytes (single-density) on one side of a minidis-
kette. By comparison, 3740-formatted eight-inch
disks store only 256 Kbytes. Enormous on-line stor-
age capacity in a 5" drive, plus proven Percom
reliability. That's what you get in a TFD-200.
The DOUBLER™ — This proprietary
adapter for the TRS-80* Model I com-
puter packs approximately twice the
data on a disk track.
Depending on the type of drive, you
can store up to four times as much
data — 350 Kbytes — on one side of a
w™"*E minidiskette as you can store using a
Tandy standard Model I computer drive.
Easy to install, the DOUBLER merely plugs into the disk
controller chip socket of your Expansion Interface. No rewir-
ing. No trace cutting.
And because the DOUBLER reads, writes and formats
either single- or double-density disks, you can continue to
run all of your single-density software, then switch to dou-
ble-density operation at any convenient time.
Included with the PC card adapter is a TRSDOS*-
compatible double-density disk operating system, called
DBLDOS™, plus a CONVERT utility that converts files and
programs from single- to double-density or double- to sing-
le-density format.
Each DOUBLER also includes an on-card high-
performance data separator circuit which ensures reliable
disk read operation.
The DOUBLER works with standard 35-, 40-, 77- and
80-track drives rated for double-density operation.
Note. Opening the Expansion Interface to install the
DOUBLER may void Tandy's limited 90-day warranty.
Free software patch This software patch, called PATCH PAK™,
upgrades TRSDOS* for operation with improved 40- and 77-
track drives. For single-density operation only.
Quality Percom products are available at authorized dealers. Call toll free
1-800-527-1592 for the address of your nearest dealer or to order directly from
Percom. In Canada call 519-824-7041.
trademark of Percom Data Company, Inc.
Prices and specifications subject 10 change without notice.
trademark of Tandy Radio Shack Corporation which has no relationship to Percom Data Company Circle 1 1 OD inquiry Card.
PERCOM DATA COMPANY. INC.
311 N KIRBY ■ GARLAND TX ■ 75042
(214J 372-3421
Circle 12 on inquiry card.
MORE FOR YOUR
RADIO SHACK
TRS-80 MODEL I !
* MORE SPEED
10-20 times faster than Level II BASIC.
* MORE ROOM
Compiled code plus VIRTUAL
MEMORY makes your RAM act larger.
* MORE INSTRUCTIONS
Add YOUR commands to its large in-
struction set!
Far more complete than most Forths:
single & double precision, arrays,
string-handling, more.
* MORE EASE
Excellent full-screen Editor, structured
& modular programming
Optimized for your TRS-80 with
keyboard repeats, upper/lower case
display driver, single- & double-width
graphics, etc.
+ MORE POWER
Forth operating system
Interpreter AND compiler
Internal 8080 Assembler
(ZBO Assembler also available)
VIRTUAL I/O for video and printer,
disk and tape
(10-Megabyte hard disk available)
FORTH
THE PROFESSIONAL FORTH
FOR TRS-80 MODEL I
(Over 1 ,000 systems in use)
MMSFORTH Disk System V1.9 (requires 1
• _ ^M)
disk drive & 16K RAM) Just $79.95*
MMSFORTH Cassette System V1.8 (requires
Level II BASIC & 16K RAM) $59.95*
AND MMS GIVES IT
PROFESSIONAL SUPPORT
Source code provided
MMSFORTH Newsletter
Many demo programs aboard
MMSFORTH User Groups
Programming staff can provide advise,
modifications and custom
programs, to fit YOUR needs.
MMSFORTH UTILITIES DISKETTE: Includes
FLOATING POINT MATH (L.2 BASIC ROM
routines plus Complex numbers,
Rectangular-Polar coordinate conversions,
Degrees mode, more), plus a full Forth-style
Z80 ASSEMBLER; plus a powerful CROSS-
REFERENCER to list Forth words by block
and line. All on one diskette (requires
MMSFORTH, 1 drive & 16K RAM), . . $39.95*
THE DATAHANDLER V1.1, a very soph-
isticated database management system
operable by non-programmers (requires Disk
MMSFORTH, 1 drive & 32K RAM); with
manuals $59.95*
FORTH BOOKS AVAILABLE
MICROFORTH PRIMER (comes with
MMSFORTH) separately $15.00*
USING FORTH — more detailed and advanc-
ed than above $25.00*
Threaded Interpretive Language — Excellent
Analysis of MMSFORTH — Like Language,
Advanced $18.95*
CALTECH FORTH MANUAL — good on
Forth Internal structure, etc $10.00*
* — Software prices include manuals and re-
quire signing of a single-system user
license. Add $2.00 S/H plus $1.00 per addi-
tional book; Mass. orders add 5% tax.
Foreign orders add 15%. UPS COD, VISA &
M/C accepted; no unpaid purchase orders,
ptease.
Send SASE for free MMSFORTH information.
Good dealers sought.
Get MMSFORTH products from your
computer dealer or
MILLER MICROCOMPUTER
SERVICES (B1)
61 Lake Shore Road, Natlck, MA 01760
(617)653-6136
■ >atteri
for a commercial graphics product, and
the vector routine uses this method. The
division itself encompasses only fifteen
instructions (30 bytes), and need be done
only once, which is before the actual
write loop is entered. The loop proper
contains only an X increment instruc-
tion, a double-precision add (two in-
structions) for the Y increment, the ac-
tual write-routine call, and a simple test
for end-of-vector. Since Mr Beetem is
using an 8080 and Unitek's system is
6800-based, a speed comparison would
be worthless. Suffice to say that the
routine actually calculates the vector
faster than the hardware can plot the
points.
To show the simplicity of the
algorithm, here is a minimal representa-
tion:
1. Find the lengths of the X and Y com-
ponents of the vector.
2. Divide the Y length by the X length.
3. Set location to X, Y origin.
4. Set the X increment to 1.
5. Set the Y increment to the result of
the division.
6 . Set the Y fraction register to hexa-
decimal 80 {Vi for round-up).
7. Plot the location.
8. If location is end-of-vector, stop.
9. Increment X.
10. Add the Y increment to the Y frac-
tion register.
11. If an overflow occurs, increment Y.
12. Go to 7.
As can be seen, the algorithm is rather
simple, and uses no complex mathe-
matics in the loop.
It turns out that this method solves a
particularly knotty problem that crops
up in other variations (especially in a
parametric line representation). When
vectors approach angles that are multi-
ples of 45° (ie: the X length nears the Y
length), varying overflow rates in the
two variables cause undesired excursions
away from the actual vector. This
creates a rough section about the points
where steps would normally occur. In-
crementing one of the variables by 1
eliminates any possibility of variable
overflow and results in a very smooth
vector.
I found Mr Beetem's logic interesting
and informative; had I considered this
method of drawing vectors when we at
Unitek were designing our graphics
package, I probably would have discard-
ed it without careful examination,
believing it too slow and complex. Mr
Beetem has proven this not to be so.
Perhaps the same thing happened when
Mr Beetem was writing his routine. He
too may have considered the slope-inter-
cept method briefly, but discarded it,
without closer examination, as being too
clumsy. (Alas, it always seems that the
algorithm one discards later turns out to
be the variation with the greatest poten-
tial....) In this case, it happened for the
best; otherwise, we would not have Mr
Beetem's method to consider. I do not in
any way intend to detract from his ap-
proach; merely to indicate that the
slope-intercept is also a viable method
for microcomputers.
CET
Richard H Rae
Unitek Ltd
POB 671
Emporia VA 23847
Fewer Resistors =
Same Resistance
In the August 1980 BYTE, W Lloyd
Milligan shows a network of twenty-six
1-ohm resistors (see "Letters," page 20)
that he believes is the smallest net-
work whose value is very close to w (pi).
However, by using the same continued-
fraction principle with only six parallel-
connected resistors, a solution with a
total of only eighteen resistors is shown
in figure 1. Alas, I have been unable to
find any network that starts with three
in series with fewer resistors; starting
with two in series, there is another solu-
tion with eighteen. All of these differ
from t by about one part in four
million. They all have the value
355/113.
Can anyone find a solution with
seventeen or fewer?
John Fitzallen Moore
714 E Birch Rd
Lake Bluff IL 60044
Figure 1
-JVW-'WWvVv-
WWVVAVvl
fWWWv-«AVi I
fVWAW-^/^A'<l
— vw-vwl
16 January 1981 © BYTE Publications Inc
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The Percom SBC/9™ is an SS-50 bus compatible, stand-
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Circle 112
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Other features:
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True baseline descenders.
• Character-store (display)!
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• Provision for optional
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Driver — called WINDEX™
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Products are available at Percom dealers nationwide. Call toll-free,
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An Introduction
to Atari Graphics
Chris Crawford and Lane Winner
Atari Inc
1272 Borregas Ave
Sunnyvale CA 94086
The Atari 400 and 800 are second-generation personal
computers. In addition to the normal memory and pro-
cessor integrated circuits, they contain three special-
purpose LSI (large-scale integrated) circuits which make
them capable of many feats of computing legerdemain.
Most of this power, however, lies brooding beneath
many layers of "human engineering." The beginning pro-
grammer working in BASIC is paternalistically protected
from the complexities and power of the beast within. The
more experienced programmer seeking cybernetic high
adventure must first defeat the friendliness engineered in-
to the machine to unleash its throbbing brute power.
Without help, this can be most difficult. We will act as
native guides for one region of this complex machine: the
display list. We will show you how to generate flashy dis-
plays by creating you own display list and redefining the
character set.
Display-List Fundamentals
Most personal computers use a straightforward mem-
ory-mapped display in which the screen format is fixed
and each screen pixel's (picture element's) contents are
provided by a specific location in memory. This is a sim-
ple scheme demanding little of either the programmer or
the computer. The Atari 400/800 uses a more complex
scheme involving a display list and display data. A dis-
play list is a sequence of commands that defines the ver-
tical format of the video display; the display data is the
information to be displayed.
The Atari 400/800 display list is actually a small pro-
gram; it is processed by a special LSI circuit called
ANTIC. ANTIC is a dedicated microprocessor whose
sole function is to control the video display. ANTIC uses
a process called DMA (direct memory access) to gain ac-
cess to the display list and display data. The display list
and display data are stored by the high-speed (1.8 MHz)
6502 microprocessor. When the BASIC programmer
types GRAPHICS n, the operating system writes a com-
plete display list into memory and clears the display data.
The information flow for this process is diagrammed in
figure 1. Clearly, the adventurous programmer who by-
passes BASIC and writes his or her own display list will
have more direct control over the screen.
Associated with the display list are the concepts of a
graphics mode and a graphics-mode line. The Atari
400/800 supports fourteen fundamental graphics modes,
only nine of which are directly accessible from BASIC.
The first six modes (three of which are accessible from
BASIC) are character modes which display characters in
different combinations of size and color. The remaining
eight graphics modes display squares of color in different
resolution and color combinations. A graphics-mode line
is a group of horizontal-scan lines which are treated as a
unit for display purposes. (A horizontal-scan line is a
single sweep of the electron beam across the television
screen. There are 192 horizontal-scan lines in the visible
area of the screen.) A graphics-mode line will contain be-
tween one and sixteen horizontal-scan lines, depending
on the graphics mode involved. A graphics-mode line
stretches horizontally all the way across the screen (you
BASIC
OPERATING
SYSTEM
6502
MICRO-
PROCESSOR
DISPLAY LIST
AND
DISPLAY DATA
ANTIC
AND
CTIA
LSI
CIRCUITS
TELEVISION
SCREEN
Figure 1: Information flow for Atari 400/800 display. The adventurous programmer who bypasses BASIC gains more control over
the display list and display data, and thus is able to customize the displayed image to a greater extent.
18 January 1981 © BYTE Publications Inc
Circle 15 on inquiry card.
MountainlJardware
MusicSystem
All the Instruments
Anyone with an Apple
MusicSysterra generates the sound of any musical
instrument— neal or imagined! Solo or sextet. Rock
or classical, laid-back or loud. At home or in the
concert hall ©r classroom. MusicSystem sets new
standards for eomputer generated music.
Digital Synthesizer with 16 Voices. Stereo output.
Polyphonic-mfjlti-voice chords and note sequen-
ces. Additive synthesis of instruments. Waveforms,
envelopes, anil amplitudes are fully programmable
for each voice to create instrument definitions arid
music dynamics. 32 Khz sample rate. Frequency
resolution ia .5Hz steps. Graphical input of sheet
music on mgh-resolution screen using standard
music notation. Print out sheet j music with a
graphicsXprinter. Complete software operating
systerosr Graphical music editor using light pen
(provided), game paddles, or keyboard. Pre-
entered music provided for immediate playing
and enjoyment. Thorough documentation and
tutorial user's manual.
Drop by your Apple, Dealer and ask to hear for\
yourself. You'll know what we mean when we say v
MusicSystem is all the instruments anyone with an
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Available nl Apple Dealers worldwide
Mountain Hardware
LEADERSHIP IN COMPUTER PERIPHERALS
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(408) 429-8600
Music I can play? Send details.
'Apple is a trademark ol Apple Computer, Inc.
cannot change graphics modes halfway across the
screen). The video display is thus organized as a vertical
sequence of mode lines of varying height and contents.
There are many thousands of possible sequences of mode
lines on the screen; BASIC restricts the programmer to
seventeen such sequences. Each such sequence is referred
to in the BASIC manual as a graphics mode.
Display-List Details
The display list and the display data normally reside at
the top of available memory-address space. Since the
amount of available memory is not fixed, the operating
system must keep track of the address of the display list.
The address of the beginning of the list is stored in
decimal addresses 560 and 561. The first 3 bytes in the
display list skip twenty-four blank scan lines, which is
necessary to defeat the vertical overscan of many televi-
sion sets. The next byte is called the LMS (load memory
scan) byte. It defines the first mode line of the display and
also instructs ANTIC that the following 2 bytes give the
address at which display data can be found. Since we
rarely need to tamper with these first 4 bytes, we will
start with the fifth byte, whose address we will assign to a
BASIC variable called START. The value of START can
be calculated by:
START = PEEK(560) + 256*PEEK(561) + 4
The bytes at this location and the succeeding location
give the starting address of the display data. Beginning at
location START +2 is a sequence of mode bytes which
specify the mode lines for the display. The codes for these
mode bytes are found in table 1. The programmer has the
freedom to create any sequence of mode bytes for the
display list. The programmer also has the responsibility
to insure that the chosen sequence includes exactly 192
horizontal-scan lines. At the end of the mode-byte se-
quence, the programmer must place an ANTIC JUMP
byte (decimal 65) followed by the low- and high-order
address bytes of the beginning of the display list — four
bytes lower in memory than the location we refer to as
START.
The starting address of the display data, which we will
assign to a BASIC variable called MEMST, can be cal-
culated from:
MEMST = PEEK(START) + 256 *PEEK(START + 1)
The display data is simply strung together in sequence;
this can cause a headache when mixing modes. Since dif-
ferent mode lines require different numbers of display-
data bytes, the programmer wishing to change a display-
data byte must calculate its position in display-data
memory by adding up the space requirements of each
previous mode line. The BASIC POSITION and PLOT
commands work reliably only with the homogeneous
display lists used by BASIC, so the programmer who
mixes modes must expend greater effort to use such a
specialized display.
A Real Display List
We shall now illustrate these principles with a sample
program and its resultant display, display list, and dis-
play data. The program is a straightforward affair which
plots the BYTE logo in graphics mode 7+16. The pro-
20 January 1981 © BYTE Publications Inc
Circle 16 on inquiry card.
A growing
line of tools to
expand the Apple.
7440A Programmable Interrupt Timer Module.
Time events in four operating modes— continu-
ous, single shot, frequency comparison, and
pulse width comparison. Includes three 16-bit
interval timers, plus flexible patch area for
external interface. Programmable interrupts,
on-board ROM, and much more.
7720A Parallel Interface. Two bi-directional 8-bit
I/O ports will connect your Apple to a variety of
parallel devices, including printers, paper tape
equipment, current relays, external on/off
devices. Full featured, programmable inter-
rupts, supports DMA daisy chaining.
781 1 B Arithmetic Processor. Interfaces with
Applesoft, so you just plug in and run. Based
on the AM 9511 device, provides full 16/32-bit
arithmetic, floating point, trigonometric, loga-
rithmic, exponential functions. Programmed I/O
data transfer, much, much more.
771 0A Asynchronous Serial Interface. Conform-
ing to RS-232-C A thru E 1978 standard, this
card will drive a variety of serial devices such as
CRT terminals, printers, paper tape devices, or
communicate with any standard RS-232 device,
including other computers. Rill hand-shaking,
and fully compatible with Apple PASCAL!
7470A 3% BCD A/0 Converter. Converts a DC
voltage to a BCD number for computerized
monitoring and analysis. Typical inputs include
DC inputs from temperature or pressure
transducers. Single channel A/D, 400 ms
per conversion.
7490A OPIB IEEE 488 Interface. A true imple-
mentation of the IEEE 488 standard-the
standard protocol for instrumentation and test
devices. Control and monitor test instruments
such as digital voltmeters, plotters, function
generators, or any other device using the
IEEE 488.
7114A PROM Module. Permits the addition to or
replacement of Apple II firmware without
removing the Apple n ROMs. Available with
on-board enable/disable toggle switch.
7500 A Wire Wrap Board. For prototyping your
own designs.
7S10A Solder Board.
7S90A Extender Board.
7016A 16K Dynamic Memory Add-On.
Watch this space for new CCS products for
the Apple. We've got some real surprises in the
works. To find out more about the CCS product
line, visit your local computer retailer. The CCS
product line is available at over 250 locations
nationally, including most that carry the Apple.
Or circle the reader service number on this ad.
Apple II, Apple II Plus, and Applesoft are trademarks
of the Apple Corporation.
CCS makes the difference.
We see the Apple
a little differently.
!"««(
tf'it;
iSl!
ft*
4*"i
^
* hi
... /
^,.
We see it as a good
way to get things done.
Apple has built a great computer. We at CCS have
built a great line of peripherals and components to expand
the Apple. To do almost anything you want to get done
with a computer.
If you want to do business with an Apple, we've got
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If you want to apply your Apple to engineering, scien-
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To find out how much computer your Apple II can be,
see things our way. Because for serious users with serious
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California Computer Systems
250 Caribbean Sunnyvale, CA 94086 (408)734-5811
Scan
Color
Lines
Dots
Per
Number
Bytes
Left
Right
Per
Mode
of
BASIC
Per
Mode
Remark
4 Bits
4 Bits
Pixel
Line
Colors
Mode
Line
character
2
Vt
8
V/2
40
character
3
Vz
10
VA
—
40
character
4
1
8
4
-
40
character
5
1
16
4
—
40
character
6
1
8
5
1
20
character
7
1
16
5
2
20
character
8
4
8
4
3
10
character
9
2
4
2
4
AO
graphic
A
2
4
4
5
20
graphic
B
1
2
2
6
20
graphic
C
1
1
2
—
20
graphic
D
1
2
4
7
40
graphic
E
1
1
4
—
40
graphic
F
«/s
1
VA
8
40
special
2
0-7
Blank
—
—
—
—
special
3
4
1
JUMP
—
—
—
—
Table 1: Interpretation of the graphics
-mode-byte
codes
. Remarks are 1
is follows:
1.
The left nybble
of the very
first mode byte of the display list must be ch
anged from to 4.
2.
The blank mode is used to
output a si
lected
number of blank background lines.
3.
The JUMP instruction causes the ANTIC graphics processor
to recognize
the end of the display list and
return to
the beginning of the list, w
aiting for vertical blanking to occur so it can
proceed with anoth
er frame.
Where IV2 colors
are indicated, the hue
of the
foreground color cannot be controlled.
Photo 1: The BYTE logo as displayed by the Atari 400/800 run-
ning the program of listing 1. See table 2 for details.
gram is presented in listing 1 (page 24), and the display it
produces is shown in photo 1. Figure 2a and table 2a
show the display list for this display. Since this is a stan-
dard BASIC graphics-mode display list, it is neat and
tidy.
Tampering With the Display List
With the formal goal of improving the display and the
heuristic goal of demonstrating display-list manipula-
tions from BASIC, we shall now tamper with this display
list. The first step in this process is to prepare our pro-
posed display list on paper. The desired screen format is
shown in figure 2b.
We must consult table 3 to determine which of the
display modes will require the greatest amount of
memory space. In our case, we are using modes 0, 1, 2,
and 7; mode 7 is clearly the most memory-intensive
mode. We shall therefore start with mode 7 and modify
the mode-7 display list. It is always easier to pare down
an oversized display list than to build up an undersized
one.
Next, we must verify that our proposed display list
does indeed produce 192 horizontal-scan lines. Consult
table 1 to find the number of scan lines per mode line.
Our calculation produces the following results:
ode
Number
Scan Lines
Total Scan
of Mode
Per Mode
Lines
Lines
Line
1
8
8
1
4
8
32
2
4
16
64
7
44
2
88
192 Total
We now determine the mode bytes for each of the
mode lines by looking them up in table 1. It is handy to
convert these to decimal for later use. Our results are:
ode
Hexadecimal
Decimal
Mode Byte
Mode Byte
02
2
1
06
6
2
07
7
7
0D
13
22 January 1981 © BYTE Publications Inc
Circle 17 on inquiry card.
MULTIUSER
COMPUTER
ON S-100 BUS
DESIGNED TO
i WIDE
VARIETY DF
APPLICATIONS.
STANDARD FEATURES
INCLUDE: CP/M i
OPERATING SYSTEM, 64K
EXPANDABLE, BANKSE-
LECTABLE MEMDR Y.4MHZ
ZBOA CPU WITH 4 SERIAL
AND 3 PARALLEL PORTS,
RELIABLE B" FLOPPY DISK
DRIVES IN A STURDY ALL
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MP/M OPTIONAL.
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P.O.BOX 1847 SAN DIEGO, CA. 92112
5333 MISSION CENTER RD SAN DIEGO, CA. 921DB
(714) 296-91B2
Listing 1: Atari 400/800 program to plot the BYTE logo, shown in photo 1. See table 2 on page 26 for details.
100
HO
120
130
SCO
BiO
820
830
90 C
905
910
915
920
925
930
935
940
945
950
955
960
965
970
975
980
9S5
99
GRAPHICS 7JC0L0
A*0!READ B*CSIF
READ A»B»C:iF A
END
ON A+l GOTO 310
plot b»c:return
drawto b»c:retu
position b»c:xi
DATA lllf30s.Hl
106*35*106
111*41*110
106*46*107
R ItPOKE 765,1 J POKE 710*123
B>-1 THEN GGSUB 80QJGOTG 1
1 THEN GOSUB SOOtGOTC 120
J POKE
10
712*128
820*830
RN
DATA
DATA
DATA
DATA
DATA
DATA
DATA
DATA
DATA
DATA
DATA
DATA
DATA
DATA
DATA
DATA
DATA
DATA
1*-1*1
?-97*30
88 * 35
79*35
77*32
71*46
67*44
58*46
,j\j * cib
51*39
49*30
49*51
46,32
45*33
36 * 30
97
0*
■f
X *
0*
2*
1,
1*
1*
? <3
,4
*4
*5
93
88
79
76
70
67
54
54
51
49
48
46
45
49
13**6*0*0
1,110,31,
6*107*37?
1*109*41
7f 107*48
96*5
1*92
1*87
2*78
1*74
1*70
1*66
2*54
0*54
li 51
: RETURN
*31
*50
*35
*31
*30
*50
*46
*31
f42
»32
*51
*33
*33
*30
*49
»48
*46
f47
,"S
109
107*33*108
103*42*107
108*49*109
*1*96*50»2
31*
51*
34*
31*
46*
51*
44*
31*
50*
33*
wllj *
43*0
51*1
-1*0*0
91*31
80*51
78*34
74*30
69
59
64
54
50
49
48*42
46*49
36*51
*43
*51
*43
*43
*51
*43
3ii»
39,
43*
50,
10
10
10
11
7*33*107*34
9,40*110*40*111*40
7*44*106*45
0*50*111*50*111*51
96*31
90*
79*
78*
93*
69*
58 *
63 ,
51*
50*
49*
48*
45*
32*1*89*33*1*89*34
50,0*79*50
33 * * 78 * 33 * 2 , 77 , 32
71*30
63*44*1*68*46
58*50
63*31*1*62,30
30 *0*
46,1*
50,0*
42 , 1 ,
31
42,0*
49
39 f Of
48fl,
oG , ,
50,39,1,50,30
48f31, 1,48*30
45 ,43
35*50*2,35*31
a)
NORMAL
96X2 = 192
TOTAL=192
MODE 7
96 LINES
b)
192
SCAN
LINES
MODIFIED
MODE 7 9 LINES
MODE O 1 LINE
MODE 7 35 LINES
MODE 1 4 LINES
MODE 2 4 LINES
9X2 =
18
1X8 =
8
35 X 2
= 70
4X8 =
32
4 X16
= 64
TOTAL=192
Figure 2: Horizontal-scan line arrangement for normal- and modified-display screens. The video screen in figure 2a is composed com-
pletely of mode-7 horizontal lines. In figure 2b, the video screen is constructed from multiple-mode sections that allow a mix of im-
ages to be displayed. Refer to table 2 for details.
The results of this paperwork are presented in table 2b.
Now, at last, we are ready to write some code. Please
refer to listing 2 on pages 28 and 30 in conjunction with
this narrative. We begin by checking to see that there is
enough memory available to reposition the display list
(line 0). If there isn't enough, the program aborts. We
then move the top of available memory down by 4 K
bytes and execute a GRAPHICS call (line 20) to write a
new display list and display data in memory. This pro-
cedure reserves 4 K bytes of memory for our own use
later on. We then define our display strings (lines 30 and
40) and execute another GRAPHICS call to initialize our
display list — which we shall subsequently modify. The
series of POKEs in lines 50 and 55 define the colors we
will be using and turn off the character display while we
redefine our characters.
24 January 1981 © BYTE Publications Inc
Circle 1B on inquiry card.
GRAPHIC
T F R KA I N A I P0CKETABLE d|g|t|zer
GRAPHIC SOFT BOX-I (12K LEVEL)
( """" ) (""" "°") ( "■'" ) ( "«"' ) ( cSStlOL ) ( """ ) ( CO°M»?»0 )
E
6
*
- t, BMW 00r UH i T II IMPUTING X-Y AXIS Bi *[v
\
T
/
<—
-»
/
1.
\
&.PATTERN ANALYSIS
FANTA STICK-I is a multifunctional
terminal that lets you draw and move
patterns on the screen, and is also
capable of analyzing drawn patterns.
FANTA STICK-I is designed to im-
prove functional performance using
integrated circuits and highly ma-
nipulative telephone keys.
It is plug compatible with APPLE-
II and especially designed for such
fields as production of commercial
animation, promotional demonstra-
tion, graphic analysis, and develop-
ment of software.
■ HARDWARE
FANTA STICK-I consists of stick,
SW1-3 switch, tenkey, I/O expansio.
connector, pilot lamp, and change
over switch on the reverse side. Stick
and CHI -3 switch are used for mak-
ing patterns and playing games.
Tenkey is used for inputing dot to
the screen, graphic mode command,
box-position command, and save
and load patterns. I/O expansion
connector is useful with I/O connec-
tor inside APPLE by only changing
switch for using expansion connec-
tor without removing FANTA
STICK-I.
If you need higher performance, you
just add another FANTA STICK-] to
I/O connector.
■ SOFTWARE
A feature of this software is the
division of the screen into twenty
individual boxes, for drawing pat-
terns, and memory. Then the boxes
are reassembled to make a whole
screen.
It does not only draw patterns by
putting together the boxes and pat-
terns made with slide and revolve
command, but composes new
screens by putting together the man-
aged pattern.
Box system has the advantage of a
close management.
There are many features, such as
making patterns with expanding box
by three times on the screen, com-
puting the area of dots in a desig-
nated window.
Using a disk, you can freely operate
a graphic pattern with save and load
command.
an
;e-
T.I. P. INC 2-1-19 Kanda-Surugadai, Chiyoda-ku, Tokyo Japan
Phone: 03-295-7055 Telex: 02226152 TIPINC I
(Exclusive Agent) HYPERSOFT INTERNATIONAL, INC.
3928 S. Sepulveda Blvd #9, Culver City, CA 90230
Phone: (213) 397-2274
DEALER INQUIRIES INVITED
Modified
Mode-7
Mode-7
Display
Display
Mode
List
Scan
Mode
List
Scan
Line
Hexadecimal/ Decimal Line
Line
Hexadecimal /Decimal
Line
Number
Number
Number
Number
LMS Byte
1
(4D) 77 2
LMS Byte r 1
(4D) 77
2
Start
_
lo
—
Start
—
lo
—
_
hi
—
—
hi
—
2
(OD) 13 4
2
(OD) 13
4
3
(OD 13 6
Mode 7
3
OD 13
6
4
(OD) i
9 lines '
4
(OD) 13
8
5
(OD) 13
10
6
(OD) 13
12
7
(OD 13
14
I 8
(OD) 13
16
Mode 0~\ ? n
1 linp / - lu
(OD) 13
(02) 2
18
26
Mode 7
i imc j
r 11
(OD) 13
28
96 lines
Mode 7
12
1
(OD) 13
30
1
35 lines <
\
{
44
(OD
I 13
94
[ 45
(OD
) 13
96
r 46
(06
6
104
Mode 1 J 47
06
6
112
4 lines \ 48
(06
6
120
'
'
'
'
' ^
'
<- 49
06
6
128
r 50
07
7
144
94
(OD) 13 188
Mode 2 J 51
07*
7
160
95
OD 13 190
4 lines \ 52
07
7
176
96
OD) 13 192
^- 53
07
7
192
JUMP
(41) 65
JUMP
(41
65
lo
lo
hi
hi
(a)
(b)
Table 2: Normal- and modified-display lists
correspond to the lines displayed in figure 2. The program corresponding to table
2a is given
in listing 1,
and the actual displa
y is pictured in photo 1. Listing 2 corresponds to table 2b.
Mode 8 +
16
8138 Bytes
8
8112
7 +
16
4200
7
4190
6 +
16
2184
6
2174
5 +
16
1176
5
1174
4 +
16
696
4
694
3 +
16
432
3
434
2 +
16
420
2
424
1 +
16
672
1
674
992
Table 3: Memory requirements for various graphics modes.
We then calculate the variable START in line 60. In
lines 70 thru 90, we POKE the new and different mode
bytes into the display list to create our new display list.
The offsets from START (the numbers added to START)
are simply the mode-line numbers for the new mode
lines. Thus, the offset in line 70 is 10 because the mode
byte we are POKEing is for the tenth mode line from the
top of the screen. (Remember, a mode line is not the same
as a scan line.) In line 95, we POKE the ANTIC JUMP
byte and the jump-address bytes at the end of our new
display list. The value of the jump-address bytes points to
the beginning of the display list and can be found in loca-
tions 560 and 561.
We have just created a new display list on top of the
original one. Now we must put a display onto the screen.
This will be a tricky operation; as we mentioned earlier,
the PLOT and POSITION commands will not quite work
as we expect them to. Some extra effort is necessary to
produce a display. Fortunately, our GRAPHICS 7 plot-
ting of the BYTE logo will still work the same way.
Because we have inserted a mode-0 line above it, the logo
will be shifted down on the screen by six scan lines. This
shift is so small that we can neglect it and plot the logo
with the same routine used earlier. This is done in lines
110 and 120.
Now that we have plotted the logo, we desire to print
some other characters as shown in photo 2 on page 32.
Two problems impede us: first, we must redefine the
character set to mix uppercase and lowercase characters;
second, we must calculate where these characters go.
The first problem arises from the natural limitations of
an 8-bit processor. If four colors are supported (as in
GRAPHICS 1 and 2), only 64 distinct characters can be
displayed in each color. This is because 2 bits are required
to specify the color, leaving only 6 bits to specify the
character. This restricts our available set; the Atari char-
acter set in ROM (read-only memory) supplies uppercase
and punctuation or lowercase and graphics symbols, but
Text continued on page 32
26 January 1981 © BYTE Publications Inc
There are Daisies!. . . And, There are Daisies!. . . But Vista has a Peach!
The Vista V300 is exactly that, a "peach" of a daisy wheel printer both from the standpoint of price
and performance.
Think of it, a printer at nearly half the price (when compared to models even remotely competitive in
quality) combined with the ultimate in reliability, print quality, and flexibility.
Typical Comments: "Superb print quality!", "Highly reliable.", "Definitely letter quality. . . I can't
believe the price tag.", "Best use I've seen yet of LSI Technology."
But judge for yourself — look at the V300 features and keep in mind this is a letter quality printer at
dot matrix prices.
• Tractor option available
• Print Speed — 25 CPS (Optional 45 CPS for $2,195)
• Print Wheel — Industry standard 96-character Daisy Wheel
(including the extended-life dual plastic wheels)
• Service — Prompt maintenance/service agreements avail-
able nationwide
• Interface — Industry standard parallel (RS232-C optional)
• Printable Columns — 136
• Warranty — 90 days parts and labor, one year parts only
• Proportional, bi-directional printing • Programmable VFU
• Extensive self-test functions • Hardware and software
compatible
Vista does it again! Quality, Price and Perfor-
mance with a peach of a daisy wheel printer.
Wffff
AND, Vista Has a Complete V100 Word Pro-
cessing System for Only $4995!
The Vista V100 is a complete word process-
ing system that includes:
• Exidy Sorcerer
Computer, 48K
• V200E20 Disc Drive
System, Double
Density
• Sanyo Data Display
Monitor
• Vista V300 Printer
Full Character Daisy
Wheel
• Wordstar, CPM™ 1.4
(Includes E Basic)
• Can also be used for
Data Processing
IMMEDIATE DELIVERY
For Further Information
Call Toll Free (800) 854-8017
The Vista Computer Company 1401 Borchard Street • Santa Ana, California 92705*714/953-0523
CPM is a trademark of Digital Research
Circle 19 on inquiry card.
BYTE January 1981 27
Listing 2: Atari 400/800 program to plot the BYTE logo and the other characters as displayed in photo 2.
2C
30
40
50
55
60
70
80
90
95
11
12
20
21
22
23
24
25
29
30
31
32
33
3*
IF FRE( 0X5325 THEN PRINT "NOT ENCUG
RAMTOP=PEEK < 1 06 > J POKE 1 06 t RAMTGP-16
DIM SML$(32):3ML*(l»32> = Ii the smal
DIM MGHifc ( 41 ) t MGH* < 1 1 41 ) = a @(23A©McGRA
GRAPHICS 7+16t COLOR 2 J POKE 765 1 2
POKE 708»128JPOKE 709»40tPQKE 710 »1
START=PEEK ( 560 ) +PEEK ( 56 1 ) *256+4
POKE START+10»2
FOR X=0 TO 3 t POKE
FOR X=0 TO 3: POKE
POKE START+54»65:
o a=o:read b»c:if
n MEMORY! "J END
: GRAPHICS
1 systems Joi.irn3l
WeHILLB@e@eS@SPUBLICATION'
:s:poke 712,123
START+46+X»6:NEXT
START+50+X»7tNEXT
:POKE START+55»FEEK
B>-1 THEN G0SU3 80
READ A»B»C:iF A>-1 THEN GOSUB 80 0J
CHBAS=RAMTQP-4 : ADDR=CHBAS*256
FOR X=0 TO 1023: POKE ADDR+X»PEEK (5
POKE 756>CHBAS+2
FOR X=0 TO 255: POKE ADDR+512+X rPEE
FOR X=0 TO 7: POKE ADDR+5i2+X»0 JNEX
FOR X=0 TO 7: READ A: POKE ADDR+99*S
POKE 755 r0 {POKE 87 ,
G POSITION 4,9:? #6? "AUGUST 1980 Vo
MEM3T==PEEK ( START ) +PEEK ( START+1 ) *25
C FOR X=l TO LEN<8ML$)JPGKE CHRP03+X
CHRPGS=CHRFQS+6
C FOR X-l TO LEN( MGH* ).l POKE CHRPOS+X
X
X
(560) IPOKE START+56r PEEK (561)
o:goto 110
GOTO 120
7344+XKNEXT X
K(ADDR+256+X):NEXT X
T X
+x»a:next x
luirie 5, Number 8° *
6 : CHRP0S-MEMST+46*4
-1»ASC<SML*(X»X))+128:NEXT X
•l»ASC(MGH$(XfX))-64:NEXT X
Listing 2 continued on page 30
A MAJOR NEW YORK BANK
INVITES YOU TO BANK AT HOME
. . . By Personal Computer
Our system talks with Yours. A program diskette provides
access to the bank for!
bill paying
account transfers
balance inquiry
record keeping
Software requires 48K bytes of memory and one disk drive.
This is a pilot program. For more information. Please terminate
this message by sending in the form below.
NAME
ADDRESS.
TELEPHONE NO
Name and type of system
Do you have communications capability?-.
If not. are you planning for it?
MAIL FORM TO! Home Banking System
P.O. Box 721
Radio City Station
--~_ New York, New York 10101
.CITY STATE.
.ZIP.
28 January 1981 © BYTE Publications Inc
Circle 20 on Inquiry card.
THE DAWN OF
A NEW AGE
The 2nd Generation is here!
MEASUREMENT systems & controls proudly
introduces its new and exciting "2nd Generation"
family of S-100* compatible products. Each has
been specifically designed for use with
multi-user and network
operating systems such
as MP/M, CP/NET, and
OASIS. Every product is
fully tested and burned-
in, comes with a 1 year
guarantee, and offers
you features not
currently available from
any other source.
Z80 PROCESSOR
BOARD — The most
powerful CPU board available today. Outstanding
features include 4MHz operation, high-speed serial
and parallel I/O utilizing DMA or programmed
control, eight vectored priority interrupts, and a
real time clock.
MULTI-USER SERIAL I/O BOARD — For use in
expanded systems requiring up to eight additional
serial I/O ports. Features include: 16 maskable
'AH products meet the new IEEE standards.
Systems
a Division of MEASUREMENT systems 8. controls
incorporated
vectored priority interrupts, RS-232C interfaces
with full handshake, asynchronous or synchronous
operation with asynchronous baud rates to 19,200.
Available in four or eight channel versions.
DOUBLE DENSITY
FLOPPY DISK
CONTROLLER BOARD-
controls up to four Sc-
inch or 8-inch disk drives
using IBM soft sectored
formats. It features 1K
of on-board buffering,
DMA controlled data
transfers and the per-
formance character-
istics of the superior
NEC 765 chip.
64K BANK SELECTABLE MEMORY BOARD —
Features include I/O port addressing for bank
select with 256 switch selectable I/O ports for the
memory bank addressing. The memory is
configured as four totally independent 16K
software-selectable banks, with each bank
addressable on any 16K boundary.
"Attractive Dealer & OEM Prices"
~ See your nearest computer dealer, or
contact us for the complete story on
The 2nd Generation.
867 North Main St. / Orange, Calif. 92668
(714) 633-4460 TWX / TELEX: 678 401 TAB IRIN
Listing
35G
360
BCD
610
B2
83
900
9G5
910
915
92
925
930
935
940
945
95
955
96
965
970
975
98
9£5
99
999
2 continued:
POKE 7
GOTO 3
OK A+l
PLOT B
DRAWTO
POSITI
DATA
DATA
DATA
DATA
DATA
DATA
DATA
DATA
DATA
DATA
DATA
DATA
DATA
DATA
DATA
DATA
DATA
03*200
60
GOTO 8
rCJRETl
B?CiRE
ON B»CJ
11 jr 20 f 1
Q6»25>1
11*31*1
06*36* 1
10*820*8
RN
TURN
XIO 18 t*
1 1 > 2 1 * 1 1
30
6
*1Q7
9
j.
2
1
1
2
1
1
1
1
1
DATA
DATA 1
DATA
97
83
79
77
71
67
53
55
51
49
49
46
45
36
60
:o
36
3*
36
2G
29
20 »
41»
22 *
2S*
20*
96*
10? 31*10
07*37*10
97*41 * 2*
0*93*21*
1*38*40*
0*79*25*
2*76*21*
1*70*20*
1*67*40?
1*54*36*
2*54*21*
0*51*32*
1 * 49 * 22 *
1*48*41*
»46*^u*
41
1*45*23*
1*49*20*
96*96*60
/
96
1
1
1
1
1
2
•i
X
•I
1
o * o * " s ;
i-.lt
27*
31*
38*
,40
92*
87*
78*
74*
70*
66*
54*
54*
ZlX *
49*
4S*
46*
47*
* *
*0*0
*
10
107
10S
108
*1
21
41
24
21
36
41
34
21
40
23
40
33
41
" : RETUR
n,ios
3*103
32*107
39*109
6*40*2
*9i»21
»80*41
*78*24
»74*20
33
L<3
7 *
*59*41
*64*33
2*54*33
1,50*41
1*49*33
0*48*32
0*46*39
1*36*41
N
22*107*23,107*24
29*109*30*110*30*111,30
33*107*34*106*35
40*110*40, 111*40*111*41
96*21
1 * 9 , 22 , 1 * 89 , 23 * 1 * 89 , 24
2*79,40*0*79*40
2*73*23*0,78*23*2*77,22
1*93*20,0*71*20
1*69*36*1*63*34*1,68* 36
2*58*40*0,53*40
1,63*32*1*63*21*1*62*20
0*51,21
1*50*32*0*50*29,1*50*20
0,49*39
1*43,29*0*48*21*1,48,20
1*45*38*1*45*33
2*35*40*0*35*40*2,35*21
Building Blocks for
Microcomputer Systems,
Dedicated Controllers
and Test Equipment.
R 2 l/0
S-100 ROM,
RAM & I/O
BOARD
ECT's R 2 l/0 is an S-100 Bus I/O Board with 3 Serial
I/O Ports (UART's), 1 Parallel I/O Port, 4 Status Ports,
2K of ROM with the 8080 Apple Monitor Program and
2K of Static RAM.
$295.00
RM-10
S-100
RACK MOUNT
CARD CAGE
ECT's RM-10 is a rack mount 10 slot Card Cage with
Power Supply, consisting of an ECT-100 rack mount
Card Cage (19"W x 12.25"H x 8"D), the MB-10 Mother
Board (with ground plane and termination) all 10
connectors and guides and the PS-15A Power Supply
(15A@8V, 1.5A@ ± 16V). $295 00
Specializing in Quality Microcomputer Hardware
Industrial • Educational • Small Business • Personal
Card Cages, Power Supplies, Mainframes, CPU's, Memory, I/O, OEM Variations
763 Ramsey Ave., Hillside, NJ 07205
(201) 686-8080
30 January 1981 © BYTE Publications Inc
Circle 21 on inquiry card.
-JIMS
Q ATAia
Atari* &Appl<
ilc" software.
A financial VP in Massachusetts is cutting the time it takes
to prepare month-end reports from three days to three hours.
A California company is replacing most of its time-share
computer service with a personal computer and VisiCalc,
saving at least $30,000 the first year.
Thousands of other personal computer users are also sold
on how VisiCalc is increasing their productivity. Besides saving
time and money, they're simplifying their work and getting
more information that helps them make better decisions. A
typical user reaction comes from a New York dentist:
"VisiCalc has become an integral part of my business"
VisiCalc displays an "electronic worksheet" that auto-
matically calculates nearly any number problem in
finance, business management, marketing, sales, engi-
neering and other areas. The huge worksheet is like a
blank ledger sheet or matrix. You input problems by
typing in titles, headings and your numbers. Where
you need calculations, type in simple formulas
(+,— , X,-r) or insert built-in functions
such as net present value and averaging.
As quickly as you type it in, VisiCalc
calculates and displays the results.
"I am extremely impressed with Visi-
Calc's capability, flexibility and orderly
presentation of instructions'.'
So writes the director of a New York cor-
poration. He appreciates VisiCalc's powerful
recalculation feature. Change any number in
your model and instantly all numbers affected by
that change are recalculated and new results are
displayed. You can ask "What if . . 7', analyzing
Commodore is a registered trademark of Commodore
Business Machines Inc., Atari is a registered trademark of
Atari Inc.. Apple is a registered trademark of Apple
Computer Inc.
more alternatives and forecasting more outcomes. It really
increases your decision-making batting average!
When you finish, you can print a copy of the worksheet just
as it appears on the screen and /or save it on diskette.
"I like VisiCalc's ease of use"
That response comes from a Utah businessman using Visi-
Calc for production forecasts, financial report ratio analysis and
job cost estimating. Ease of use is VisiCalc's best-liked feature.
It's designed for a non-programmer, and has an extensive, easy-
to-understand instruction manual.
Users also like solving a wide variety of problems with
VisiCalc . . . and solving them their way. VisiCalc can even
justify the cost of a personal computer, according to a New
Hampshire financial analyst:
"VisiCalc is paying for itself over and over."
VisiCalc is available for 32k Commodore PET/CBM, Atari
800 and Apple disk systems. VisiCalc is written by Soft-
ware Arts, Inc.
See VisiCalc at your Personal Software dealer.
For your dealer's name, call Personal Software Inc.
408-745-7841, or write 1330 Bordeaux Drive,
Sunnyvale, CA 94086:
While there, see our other Pro-
ductivity Series software: Desktop Plan
and CCA Data Management System.
They're like time on your hands and
money in the bank.
Circle 22 on inquiry card.
AUGUST t?3G Volune s, HuHber
The Atari 400/800 display list is
actually a small program.
WS5-C-C.1
fl HCGRAM HILL
PUBLICATION
Photo 2: The BYTE logo as displayed by the Atari 400/800 run-
ning the program in listing 2.
8 BY 8 PIXEL
SQUARE
BINARY
HEXADECIMAL
DECIMAL
1 1
Figure 3: The assignment of values to create an elevated lower-
case "c" character.
Text continued from page 26:
not uppercase and lowercase together — at least not in
GRAPHICS 1 or 2. Since we want uppercase and lower-
case together, we will have to redefine the character set.
To do this, we must have some memory reserved for
the new character set. Line 20 did this by fooling the
operating system into believing that the top of memory
(called RAMTOP) lies sixteen pages lower than it actual-
ly does. This has reserved 4 K bytes for our use. The
character set needs only 1 K bytes, but the display data
cannot cross a 4 K boundary (without entailing difficul-
ty), hence we must move the display list and display data
down by an entire 4 K. The address of the beginning of
our new character set is calculated in line 200 and is called
ADDR.
In line 210, we move the original character set (starting
at address 57344 in ROM) into user memory. In line 220,
we tell the operating system where the new character set
is. In line 230, we move the uppercase characters into the
positions previously occupied by punctuation. Our new
64-member character set has uppercase and lowercase,
but very little punctuation. In line 240, we define a new
space character, as the original space character was part
of the old punctuation group. We shall use the place
previously occupied by the @ character for our space
character.
We next take this technique of defining our own char-
acters one step further. We had earlier decided to elevate
the lowercase "c" in "McGraw-Hill." To do this, we must
redefine what a lowercase "c" looks like. This is done in
line 250, with data coming from line 999. Obviously, this
procedure can be greatly extended. The diligent program-
mer can define any character set that can be expressed in
an 8- by 8-pixel grid and POKE it into user memory
directly (see figure 3). Greek, Cyrillic, or special technical
character sets can be created in this way.
We now have our display list and character set in
order. We need only display our text. This is done start-
ing at line 290. The first POKE suppresses the cursor for a
neater display; the second POKE fools the operating
system into believing that it is working in mode 0. This
prepares the way for a straightforward POSITION and
PRINT of the first text line. The only trick is that the line
is positioned vertically according to the number of mode
lines from the top of the screen.
The next two text lines pose a particularly knotty prob-
lem. We desire to print GRAPHICS 1 and 2 characters on
mode lines 46 thru 52. Neither graphics mode allows so
many lines; when we try to position the cursor onto line
46 the computer will generate a "cursor out of range"
error. Our only recourse is to POKE the character bytes
directly into the display memory. We do this starting at
line 310. First, we calculate the starting address of the dis-
play memory (MEMST). Then we calculate the address
where our characters are to be stored (CHRPOS). Our
calculation relies on the fact that the characters are on the
46th line and all previous lines used 40 bytes each. In
more complicated situations, we would have to add up
the byte requirements of all previous lines. This can get
messy when a display mixes mode-1 or mode-2 lines at 20
bytes per line with other modes that use 40 bytes per line.
Fortunately, our case is simple. Once CHRPOS has been
calculated, we POKE the character values into the dis-
play data using a simple loop (line 320). Adding 60 to
CHRPOS (line 330) skips three of our 20-byte mode-1 or
mode-2 lines. We then POKE the character values for our
third text line using the same technique we used in line
320, except that a different character-value offset ( — 64
instead of + 128) gives us green characters instead of red
ones. Line 350 turns the characters back on.
Conclusion
The two major tricks we have demonstrated in this ar-
ticle (modifying the display list and redefining the char-
acter set) will greatly extend the graphics and display
power of your BASIC programs. The Atari 400/800 run-
ning BASIC alone has stunning graphics capabilities.
With these tricks, the machine brings previously un-
heard-of capabilities into the hands of the personal com-
puter owner. Yet, we are still just trundling down the
runway. There are even grander functions built into this
machine — movable graphics objects for animation, ver-
tical and horizontal fine scrolling, and display-list inter-
rupts, to name a few. With these tricks in hand, we can
soar beyond the limits of yesterday's color display and
animation. ■
32 January 1981 © BYTE Publications Inc
Circle 23 on Inquiry card.
The Panasonic and Quasar
Hand-Held Computers
Beginning a New Generation
of Consumer Computers
Gregg Williams, Editor
Rick Meyer, Friends Amis
c/o BYTE
70 Main St
Peterborough NH 03458
Arthur C Clarke talked about them
in his futuristic novel Imperial Earth.
Jerry Pournelle and Larry Niven
talked about them in The Mote in
God's Eye. The subject is hand-held
computers that can run programs, re-
mind you of upcoming appointments,
and serve as portable intermediaries
between you and large, immobile,
mainframe computers. Are they still
science fiction? No, the hand-held
computer is here — and for less than
the price of some color televisions.
The HHC (hand-held computer) is
a device about the size of a standard
paperback book with two inches
added to its longest dimension (see
photo 1). Its weight is under a pound,
yet it has the capabilities (when ex-
tended with portable peripherals) to
do anything that existing personal
computers do. The device, developed
jointly by the Japanese corpora-
tion Matsushita (pronounced mat-
SOOSH-ta) and Friends Amis of San
Francisco, is being marketed in
America by Panasonic and Quasar.
Photographs in this article show both
It is impossible to lose
the work you are do-
ing by pressing the
OFF key.
the Quasar and the Panasonic ver-
sions.
Description of the HHC System
The Quasar/Panasonic HHC is an
integrated package of hardware and
software that has the ability to do
anything that other personal com-
puters do. The HHC unit has the
following characteristics:
• Dimensions: 22.7 by 3.0 by 9.5 cm
(8 15 / 16 by 1 3 / 16 by 3% inches);
• Weight: 397 grams (14 oz.);
• 6502 microprocessor running at
1MHz;
• Sixty-five-key keyboard with two-
key rollover;
• 159 by 8 dot low-persistence LCD
(liquid-crystal display);
• Uninterrupted storage of all user
programs and other data through use
of a unique "power-down" circuit;
• Redefinition of all keys during
execution of an application program;
• Redefinition of all characters
displayed on the LCD display and
printer during execution of an
application program;
• 2 K bytes of programmable mem-
ory, expandable to 4 K bytes internal-
ly or any practical limit (up to a
theoretical limit of 4 megabytes) ex-
ternally, by adding programmable
memory peripherals;
• 16 K bytes of internal ROM (read-
only memory) with sockets for four
program capsules containing up to
64 K bytes of application programs
or data (additional ROM, up to a the-
oretical limit of 4 megabytes, can be
added externally through ROM
peripherals);
• An internal real-time clock with a
resolution of y 2S6 second;
• A built-in nickel-cadmium battery
34 January 1981 © BYTE Publications Inc
How to tell if it's a White Computer.
You see, it isn't always white.
Until now, if you bought a White
Computer it was dressed up as some-
one else's system. Mow the White
Computer is available under its own
nameplate.
And the features that make the
White Computer the choice of many
system builders also make the White
Computer an excel tent choice for you.
Features like White's guarantee to
ship replacement parts within 24
hours of your telephone call. CP/M®
and MP/M™ operating systems. Full
upgrade routes to multi-user and
hard-disk performance. (Like the
3-user 35 megabyte system shown.)
And 8-bit or 16-bit configurations.
Features that make the White Com-
puter the reliable, high performance
system you need for business, or
software development, or industrial
control uses.
So if you buy a computer that's
not white, it might still be White. But
make sure. Because if it's not White,
chances are you're paying more, for
less computer.
White Computers are now
available from computer dealers
nationally. Call or write for more
information, and the name of your
nearest dealer.
CK/M is a registered trademark ol Digital Research.
MI7M Is a trademark of Digital Research.
White Computer Company A 1876 Industrial Way
Redwood City, California 94063 A 415 364 7570
Photo 2: The HHC and its peripherals. The HHC computer is in the center of the
photograph. The peripherals are (clockwise, from upper left): a programmable-memory
extender, the color television interface, the I/O driver (a distributor of bus signals from
the HHC to other peripherals), an acoustic-coupler modem, a portable printer, a
cassette interface, and a ROM expander.
All functions are
selected via a set of
nested menus.
enough current to retain the contents
of the HHC's display image and
CMOS (complementary metal-oxide
semiconductor) memory and to pre-
serve the real-time clock and key-
board functions. A side benefit of this
feature is that it is impossible to lose
the work you are doing by pressing
the OFF key; when you press the ON
key, the computer resumes whatever
it was doing before it was turned off.
A specially designed 44-pin bus
connector allows you to connect and
disconnect the HHC and its periph-
erals while all the components are
powered up. Because of this feature,
the HHC and its peripherals can join
their respective data, address, and
control buses without destroying data
in either unit. As an additional safety
feature, the piezoelectric beeper in-
side the HHC sounds if the HHC finds
any loose connectors.
The ability to connect and discon-
nect modules while the power is on is
very important because it allows the
unit to be used in a variety of com-
binations without worrying that data
will be destroyed by doing so. The
HHC and its peripherals can be con-
sidered as interconnecting modules,
and you can effectively forget that
they contain volatile data. For exam-
ple, when future program-develop-
ment capsules become available, you
will be able to write a program while
traveling, then debug it more easily
by hooking the HHC into the color
TV adapter and printer. Data can
also be entered into an HHC memory
peripheral that may then be detached
from the HHC and given to another
HHC owner. He or she can plug it in-
to another HHC and access the data
that was stored.
Friends Amis has invented a par-
ticularly elegant solution to the
packaging of programs in ROM
(read-only memory). This solution
also allows denser storage of informa-
tion than was previously possible.
The HHC uses 24-pin ROMs that are
packaged in a plastic carrier around
which the pins of the ROM are bent
(see photo 3). This combination is
called an Amis Memory System Cap-
sule (patent pending). (When a cap-
sule is inserted into the back of the
HHC, the flat base of each pin makes
contact with the socket. This insures
a good electrical contact without the
usual fragility of integrated circuit
pins.) Since a minimal amount of
hardware is used to package the
ROMs, more can fit inside the small
body of the HHC.
These capsules have already been
used in the Craig, Panasonic, and
Quasar language translators (also
developed by Friends Amis), and in
the Friends Amis point of
information display computer. Cap-
sules can contain data to be
manipulated (eg: words in a French
language capsule), application soft-
ware (eg: a capsule of game pro-
grams), programming languages (eg:
a BASIC capsule), or any other data
that the computer can act upon. Cap-
sules can hold 2 K, 4 K, 8 K, or 16 K
bytes of information. The 16 K-byte
ROM allows an unprecedented
amount of data to be stored in a small
space. The large amount of informa-
tion that can be stored in the HHC is
increased by its internal use of a
threaded language and by the ap-
plication of a set of data compression
techniques.
Human-Engineered Features
As a direct result of the manufac-
turers' desire to design a computer
specifically for the mass market, the
Quasar/Panasonic HHC was devel-
oped with a heavy emphasis on
human engineering. This design
philosophy is reflected in the opera-
tion and features of the HHC.
The keyboard has always been a
crucial interface between the user and
the computer, and the popularity of
several existing microcomputers has
been largely influenced by the us-
ability of their keyboard. This fact,
coupled with the small size of the
HHC, makes it necessary for the
HHC keyboard to be as usable as
possible. We feel that the designers
have achieved this objective.
[Despite my initial disbelief that a
keyboard this small could be of any
practical use, I was soon convinced
that the HHC keyboard is easy to use
and that, given some familiarity with
it, I could use the keyboard without
being distracted from the task at
hand... GW]
Photo 1 indicates that the keys on
36 January 1981 © BYTE Publications Inc
pack that supplies all power to the
unit;
• Internal shielding against RF (radio-
frequency) interference in compliance
with the new regulations from the
Federal Communications Commis-
sion;
• An internal set of application pro-
grams that includes a four-function
calculator, a free-form file system and
editor, as well as several other func-
tions.
In addition, the capabilities of the
HHC are greatly extended by an in-
tegrated system of intelligent periph-
erals that include:
• A bus expander through which
other modules are connected to the
HHC;
• A portable thermal printer that
prints 16 characters per line;
• A ROM extender that allows you to
attach an additional four program or
data capsules;
• A programmable-memory extender
that allows you to add additional
memory to the HHC;
• A 110/300 bps modem and tele-
computing program through which
the HHC can act as a remote terminal
to other computers and to large infor-
mation utilities and data bases;
• A cassette interface module that
transfers data to a microcassette
recorder at 1200 bps;
• A color television interface that
allows a display of 16 lines of 32 char-
acters each or up to 48 by 64 pixel
(picture element) graphics in eight
colors and black.
When connected to the HHC, all of
the above peripherals can fit in a
custom case the size of an average
attache case, or they can be intercon-
nected to make a flat, rigid, easily
portable combination. With the ex-
ception of the color television inter-
face, the HHC and the peripherals
can operate without connections to
any outside power source, thus mak-
ing the system truly portable and
hand-held. Photo 2 shows the HHC
and several of its peripherals.
Innovations in the HHC
The Panasonic/Quasar HHC em-
bodies several technical break-
throughs. Without these develop-
ments, a computer as small and as
powerful as the HHC could not have
been built.
One of the most important innova-
Photo 1: The Panasonic and Quasar HHCs (hand-held computers). Both units
shown are prototype models and will have the same keyboard layout in the
finished versions.
tions in the HHC is the proprietary
"power-down" circuit that allows the
HHC to use the popular 6502 micro-
processor in a hand-held device. In
the past, manufacturers have
designed hand-held products around
microprocessors like the 1802. Such
devices use a very small amount of
current and can be powered by bat-
teries, but they force the designer to
use a slow microprocessor with a
weak instruction set.
Designers have been prevented
from using the more popular micro-
processors because of their high cur-
rent drain: a conventional 6502-based
circuit (using the same batteries as the
HHC) would discharge them in about
two hours. But, with this power-
down circuit and additional hardware
innovations, the amount of current
needed to power the HHC in both its
fully functioning and "off" (powered-
down) modes is drastically reduced.
A related feature of the HHC is that
when the OFF button has been
pressed, the computer is still on. It is
in a dormant state that uses only
January 1981 © BYTE Publications Inc 35
the HHC are arranged in the standard
typewriter format. In addition, a key
can be pressed without pressing any
adjacent keys, so it is possible to
touch-type on the HHC, regardless of
individual finger width. This fact
allows the HHC to be used in text ap-
plications — an area not practically
accessible by any other device of its
size.
Another powerful feature of the
HHC is its ability within an applica-
tion program to redefine any key
position to any function. With the
addition of a keyboard overlay, this
can provide a keyboard that is com-
pletely suited to a given application.
It was the intention of the HHC de-
signers that no application, regardless
of complexity, would require mem-
orization of command language or
special key sequence (like control-P
for print) to perform a function avail-
able to the computer but not allotted
a key. With redefinable keys and
keyboard overlays, this will never
happen.
Three special keys, labeled fl, f2,
and f3, can be assigned to be any se-
quence of keystrokes, including most
function keys. When one of these
keys is typed, its current definition is
input as if the sequence of keys had
been typed by the user. The defini-
tions are processed as interrupts and
are independent of the program in
use. Thus, they can be used with any
present or future programs, even
those written in BASIC or SNAP (the
two computer languages currently
planned for the HHC). For example,
one key can be assigned to a sequence
of calculations and/or constant
values for use with the built-in
calculator. Another key can be used
to enter repetitive text in the memory
bank text editor or to create special
functions such as search-and-replace.
Another definition can be used to
make a commonly used sequence of
menu selections to reach a frequently
used program.
A unique feature of the HHC is the
HELP key. When this key is pressed,
you are prompted by the LCD display
to press any key to find its definition.
When a key is pressed, the function is
given in a complete sentence of up to
80 characters. For example, pressing
the HELP key followed by the
STP/SPD key causes the message
"STOP / ENTER 1-9 FOR SPEED" to
be displayed.
Four HHC keys are used to indicate
LEFT, RIGHT, UP, and DOWN. In
most programs, these keys are used
for cursor control and horizontal and
vertical scrolling. Since the HHC's
built-in display shows only one short
(26-character) line at a time, it is im-
portant to be able to "steer" the
display through a larger page or list
of material. The display is often used
as a window into a larger virtual
space (as is done in the popular
VisiCalc program), and the four
direction keys, which are auto-repeat
keys, move the window in any direc-
tion. Another key, STP/SPD (stop/
speed), allows you to freeze and con-
tinue any program, like a run/
stop switch, and to adjust the rate of
information display.
The HHC also has INSERT and
DELETE keys that allow text material
to be changed. The HHC normally
displays a solid rectangular cursor,
but when you enter the insertion
mode, the cursor changes to a blink-
ing checkerboard cursor. Similarly,
WORD
FIRST
NUMBER*
LETTERS BORROWED
FROM LAST WORD
FIRST
LETTER
NOT
COPIED
SECOND
NUMBER*
(COUNT
FORWARD)
NEXT LETTER
OF NEW WORD
REMAINING
LETTERS OF
NEW WORD*
SLOW
-_
__
__
__
__
__
SLUMP
2
SL
+
6 =
U
MP
SLY
2
SL
u +
4 =>
Y
—
SMALL
1
S
L +
1 =
M
ALL
SMART
3
SMA
L +
6 =
R
T
Figure 1: Compression of an alphabetized list. The tables of alphabetized lists within
the HHC are kept as small as possible by using numbers to keep track of the number of
letters shared from the previous word and the number of letters between the first dif-
ferent letter in the new word and its counterpart in the previous word. Note that the
shaded letters on a line make up the word being encoded, but only the two numbers and
the letters in the last column (all marked with an asterisk in their table headers) are ac-
tually stored in the encoded table. The dashes indicate an empty entry (as in the line for
the word SLY). The first line is all dashes because it does not have a previous line to
refer to; in practice, all the letters of the first entry must be normally encoded.
Photo 3: Close-up of an HHC program capsule. The program capsule is actually a stan-
dard 24-pin integrated circuit with its pins curled around a plastic harness. Its length is
3.65 cm (l 7 /i b inches).
January 1981 © BYTE Publications Inc 37
Photo 4: The Quasar HHC connected directly to its acoustic coupler. The combina-
tion, which is also available in the Panasonic HHC system, is a self-contained portable
computer terminal.
The computer executes
a FORTH-IIke language
called SNAP.
when you enter the deletion mode,
the cursor changes to a rectangular
outline cursor. These useful features
give you visual feedback regarding
the mode that the computer is in.
Other keyboard-related features
are the search and locate commands
available within the memory bank
electronic file system. These features
are available in two modes — context
and initial search. A context search
searches for a match to the given
character string anywhere in the file,
while an initial search searches for a
match beginning with the first char-
acter of each record in the file. The
former method allows maximum
searching power, but the latter pro-
vides a faster search when the posi-
tion of the string to be matched is at
the beginning of each record (eg:
when the file contains last names and
telephone numbers and you are given
the last name).
Other strong keyboard features of
the HHC are the size and placement
of certain keys. The SPACE and
ENTER keys are in their traditional
positions, and both are wider than
the other keys for ease of use. Also
notice from photo 1 that the CLEAR,
ON, and OFF keys are located five
rows to the right of the rightmost let-
ter key, and at least two rows to the
right of any other key. Although the
consequences of hitting these keys by
accident are less critical than on other
personal computers (more on that
later), the keys were placed there to
minimize the danger.
Finally, the behavior of the SHIFT
and LOCK keys should be mention-
ed. In applications where the pro-
gram differentiates between upper-
case and lowercase letters, an upper-
case letter is obtained by hitting the
SHIFT key, followed by the key to be
shifted. The HHC is locked into up-
percase by hitting the LOCK key after
the SHIFT key. You can return to
lowercase by hitting either the SHIFT
or LOCK keys. The LOCK key can
also lock the four cursor-control keys
and the INSERT and DELETE keys.
The Menu and Other Features
To allow for use of the Panasonic/
Quasar HHC with minimal prior
knowledge of the machine, all func-
tions are selected via a set of nested
menus. The first menu that appears
when the computer is turned on is
called the primary menu. It displays
the available internal and capsule
program choices (eg: clock/secretary,
program capsule, etc) with a 1-digit
number assigned to each. A choice is
selected by pressing the correspon-
ding digit key. If the selected applica-
tion allows choices of its own, its
menu is displayed in the same way.
This process is repeated until an ex-
ecutable program is reached. Pressing
the CLEAR key causes the HHC to
display the second menu (the one
immediately after the primary menu).
Pressing the CLEAR key twice causes
the HHC to return to the primary
menu.
The HHC computer contains a
piezoelectric beeper that can produce
either a click (to provide audible feed-
back to an event, usually a keypress)
or a tone within a four-octave range.
Squeezing More into Less
There has been recent publicity on
threaded languages — most visibly
FORTH. (See the special language
issue on FORTH, August 1980
BYTE.) Threaded languages offer
program compactness and speed of
execution halfway between those of
machine language and a high-level
language like BASIC, while offering
the programming ease and language
transportability of high-level lan-
guages.
The Quasar/Panasonic HHC is
actually a hardware machine that
executes a FORTH-like language
called SNAP, in addition to 6502 ma-
chine code. The HHC uses SNAP for
every function that it performs, from
the display of characters on the LCD
readout to the handling of interrupts
from the peripherals. When timing is
critical in a specific routine, such as
interrupt handling for high-speed pe-
ripherals, SNAP allows any portion
of itself to be coded in assembly
language for maximal speed.
SNAP, like other threaded lan-
guages, is defined in terms of a given
set of operators (which are analogous
to the operation codes of a given
microprocessor). SNAP programs are
simply lists of these operators, so
these programs (including applica-
tions programs embedded in program
capsule ROMs) may be used without
change on any machine that executes
the SNAP language, provided no ma-
38 January 1981 © BYTE Publications Inc
chine code is used. This protects the
sizable programming effort put into
the HHC against hardware innova-
tions in future versions of the HHC,
while maintaining a body of pro-
grams that execute quickly and use
little memory.
Another way in which the execu-
tion time of programs is decreased is
through the use of interrupts for the
HHC keyboard and all peripherals. In
contrast to other computers which
use polling (ie: they periodically
check the device to see if it needs
computer time), the HHC peripherals
and keyboard generate interrupts
when they require attention from the
6502 microprocessor. In this way
several peripherals can be serviced at
once. The HHC slows down only
when it is interrupted to do specific
work and is therefore faster than
computers that waste time polling in-
active devices. The HHC peripherals
that require serial data all use
separate UART (universal asyn-
chronous receiver-transmitter) in-
tegrated circuits for this purpose.
Given the 64 K-byte maximum ad-
dressing ability of the 6502
microprocessor, the HHC must
somehow pack more memory into
less space. It does so, using the
familiar technique of bank-switching.
Three banks of memory, hexadecimal
2000 to 3FFF, 4000 to 7FFF, and 8000
to BFFF, are bank-switched. This
means that several blocks of up to
16 K bytes of memory could be
assigned to one of the above address
areas, with electronic circuitry en-
abling only one such block to be
active at a time.
The program capsules that insert
into the back of the HHC all map into
the same 16 K-byte address area:
hexadecimal 4000 to 7FFF. Only one
capsule is active at a time and is
selected from the HHC primary
menu. This area is also used for user
data and programs.
The 16 K-byte area from hexa-
decimal locations 8000 to BFFF is used
for external programmable memory
banks. Since this bank is in a different
address area from ROM banks, many
ROM-based programs can reference
data in programmable memory with-
out bank-switching.
The 8 K-byte address area (from
hexadecimal locations 2000 to 3FFF)
is used by the specialized firmware
that is contained in each HHC
peripheral. When a given peripheral
is being used, the firmware that con-
Letter
E
T
I
O
N
S
Huffman Code
000
001
010
0110
0111
1000
(a)
Code
Bit(s) to
Be Matched
Comments
100111
--no match
01001 1 1
01
--no match
0100111
010
--matches I
(I1P_111
--no match
(1)011 1
01
-no match
(DQ1J1
011
-no match
(1)01 1 1
0111
-matches N
(I) (N)
done
--message is IN
(b)
Table 1: An example of Huffman coding. Table la shows an example Huffman
code for several letters. Table lb shows how the code 0100111 is decoded into the
letters I and N. Bits are taken from the left side of the remaining binary string until
the sequence of bits matches one of the table entries. Notice in table la that the
code for no letter is a beginning substring of the code for another letter. (This, for
example, accounts for the fact that no letter is given to the bit string 011 — it would
conflict with 0110, the code for the letter O.) Every Huffman code (of which there
are an infinite number) is constructed so that no two letters can be confused with
each other. If the letters are assigned codes in the order of their decreasing fre-
quency for the text to be decoded, a Huffman code permits the maximum data
compression possible.
Table Number of Elements
Rank(N) in Table ( = 2~)
1 2
2 4
3 8
4 16
5 32
6 64
Number of Bits
In New Permutation
Algorithm
(F(N) = 2~ + 2F(N-1))
1
6 = 4 + 2(1)
20 = 8 + 2(6)
56 = 16 + 2(20)
144 = 32 + 2(56)
352 = 64 + 2(144)
Number of Bits
In Ordinary Look-up
Table (=N2 N )
2
8
24
64
160
384
Table 2: Efficiency of the permutation algorithm given in figures 2 through 4 and
the text box. As can be seen from the last two columns, this algorithm uses fewer
bits to define a given permutation. The ordinary look up table uses a table 2"
entries long by N bits long to look up the value (from to 2 N —1) that a given
element (in the same range) is permuted to.
trols its communication with the
HHC is selected and used. This area
also contains the memory-mapped
contents of the video display when
the HHC is connected to the color TV
interface.
In both 16 K-byte bank-switched
areas it is possible to reference a pro-
gram or a program/data combination
that is more than 16 K bytes long.
The program (or program and data)
is divided into 16 K-byte blocks, all
of which map into the same area.
Under program control the software
can then jump between 16 K-byte
blocks by writing the appropriate
value to a location in the HHC that
determines which block is currently
selected.
Text Compression in the HHC
The increase in data storage caused
January 1981 © BYTE Publications Inc 39
a)
l
2
b)
Figure 2: Two possible outcomes for the
permutations of a two-element list. See
the Mapping Algorithm text box for
further details.
by the use of SNAP and 16 K-byte
program capsules is significant. But
the increase caused by the use of data
compression techniques is even more
significant, almost doubling the
amount of information that can be
stored in an HHC data capsule. A
variable word-length code and in-
creased data compaction through
context are the two techniques used.
In traditional data storage, one
character of information is stored in a
byte (or 8 bits or binary digits) of
computer memory. Letters, numbers,
and punctuation are stored in the
ASCII (American Standard Code for
Information Interchange) format,
which uses 7 bits per character. Using
a method developed by Friends Amis
that modifies what is called a Huff-
man code, variable bit-length codes
can be devised for the characters to be
encoded such that frequently used
characters will be given shorter codes
(called codons), thus decreasing the
average number of bits used per
character. Table 1 shows an example
of a standard Huffman code (there
are an infinite number of such codes).
Because of this variable-length
coding, the computer's memory is
seen as a long string of bits. Bits are
read from left to right (figuratively
speaking) until the bits read match
the codon for any character in the set.
(Codons are generated by rules that
guarantee that a beginning string of
bits can match the codon of only one
letter in the set.) Codons are also
devised so that the most frequently
used letters have the shorter represen-
tations and are also near the top of
the look-up stack. Because the num-
ber of look-up entries read before a
match occurs is kept to a minimum
(on the average, slightly more than
eight entries), the decoding process
does not slow the machine down.
A further measure of compression
is made by modifying the look-up
procedure to be sensitive to the con-
text of the previous letter. For exam-
ple, even though the most frequently
used letters in normal English text are
(in decreasing frequency) E, T, I, O,
N, and so on, if the previous letter
looked up was Q, then the letter U is
most probably the next letter and so
should be close to the beginning of
the look-up table. Within the HHC,
the letter-decoding routine uses the
previously decoded letter to index
one of several look-up tables. In this
way, encoded characters can be re-
presented in even fewer bits than
would otherwise be possible using
straight frequency-determined co-
dons.
Two more techniques are used
within the HHC to decrease the
number of bits used to represent
character information to a final
density of just over 4 bits per char-
acter. Although these techniques
were developed to deal with alpha-
betized lists of words (for the Friends
Amis language translator), it is possi-
ble to use them to compress nonal-
phabetized text in some situations.
The first technique replaces the
beginning of each word (except the
first word in a list) with two numbers.
The first number tells how many let-
ters to borrow from the previous
word. The second number tells how
many letters away the first non-
matching letter is from its counterpart
in the previous word. For example, if
the words are SMALL and SMART,
the following is stored for the word
SMART: 3 (telling the computer to
borrow SMA from the word
SMALL); 6 (telling the computer to
count forward six letters from the L in
SMALL to arrive at the R in
SMART); the encoded letter T
(ending the encoding of the word
SMART). (See figure 1 for other ex-
amples.) Because the two numbers
(contained in 3 and 4 bits, respective-
ly) take up fewer bits than the letters
The Mapping Algorithm
It is sometimes profitable to
maintain a list of words in alpha-
betic order but to be able to
retrieve them in some other pre-
specified order. The problem then
becomes one of finding the most
compact way of specifying a per-
mutation of N elements from (l, 2,
3, . , N) to some other ordering.
The algorithm used within the
Panasonic /Quasar HHC requires
that the list be a power of 2 (ie:
have 2, 4, 8, 16, 32, 64,... ele-
ments). The algorithm can be con-
sidered as a recursive set of pair
switchings. The permutations of a
list of two elements can be re-
presented by 1 bit of informa-
tion—say, aO to represent that the
elements are not switched, eg: (1,
2) becomes (1, 2); and alto repre-
sent that the elements are switch-
ed, eg: (1, 2) becomes (2, 1). This is
represented pictorially in figure 2,
where a box represents 1 bit of in-
formation.
The diagram in figure 3a is used
with a list of four elements. The
upper-lefthand box is always filled
in with an equal sign (=). The in-
put arrangement, usually (1, 2, 3,
4), is substituted for INI thru IN4,
and the desired permutation is sub-
stituted for OUTl thru OUT4. The
boxes in the first and third columns
are filled in with either equal signs
(=) or cross signs (X), leaving the
boxes in the second column for
last.
Consider the example of permut-
ing the list (1, 2, 3, 4) to become (4,
1, 3, 2). Given the interconnections
between boxes and the constraints
given above, the only path that
can be taken from 1 to 1 goes
through the top middle box (in a
manner not yet specified) and to
the righthand side through a cross
in the upper-right box, as shown in
figure 3b. In figure 3c, the element
4 is traced from box A to box B.
Similarly, element 3 is traced from
box B to box C, and element 2 is
traced from box B to box S, where
we started.
Given the conditions shown in
figure 3c, it is a simple task to fill
in the middle columns, thus com-
pleting the diagram. The finished
diagram is shown in figure 3d.
Through use of this diagram, the
list (1, 2, 3, 4) can be permuted to
the list (4, 1,3,2) using 6 bits of in-
formation (1 bit for each of the six
boxes).
Study of an eight-element list ex-
ample illustrates the recursive
40 January 1981 © BYTE Publications Inc
they replace, this method can repre-
sent the same text in fewer bits.
The last technique saves space in
that it allows alphabetized lists to be
used in a different order. (For exam-
ple, in language lists a given set of
words is mapped from the sequential
order in its alphabetized list to a
semantic order in a list of words of
equivalent meaning available in each
language list; this is done so that the
computer can translate a given word
to its equivalent in another language.)
With this technique, a list of 2 N
elements can be permuted into any
other arrangement of the same ele-
ments by a relatively small number of
bits of information (see table 2). Refer
to the Mapping Algorithm text box
for the details of this algorithm.
The Real-Time Clock
One of the most important internal
features of the Panasonic /Quasar
HHC is its real-time clock and event
sequencer. The real-time clock exists
in memory as a 40-bit number stored
method that is used to generate the
final structure for longer lists.
Figure 4 shows a mapping of the
list (1, 2, 3, 4, 5, 6, 7, 8) to (6, 3, 8,
1, 7, 5, 4, 2). As before, box S is
marked with an equal sign. Boxes
in the first and last columns are
then filled in; this can even be done
with no knowledge of the contents
of boxes X and Y. The boxes A
through G are filled in alpha-
betically. Note that when these
boxes are filled, the boxes X and Y
become "black boxes" that map
four-element lists into another
ordering. These boxes are then
solved as shown in figure 3, and
the permutation of eight elements
is now solved. The final solution
has twenty boxes: eight as shown
in figure 4, plus six boxes each for
boxes X and Y.
Larger lists are solved in an ana-
logous way, with a list of 2 N
elements first filling the 2 N boxes in
the first and last columns, followed
by the solution of the two middle
boxes, each of which permutes a
list of 2' elements. Table 2 shows
the number of boxes (or bits) nec-
essary to solve larger permuta-
tions.
•0UT2
•0UT3
-0UT4
©
1
P
1
X
3
3
Figure 3: Solving a four-element permutation problem as a network of binary deci-
sions. Figure 3a shows the initial configuration used in the solution of any four-element
permutation. Figures 3b, 3c, and 3d show steps in the solution of this problem. See the
Mapping Algorithm text box for further details.
January 1981 © BYTE Publications Inc 41
in 5 contiguous bytes of program-
mable memory, supported by a hard-
ware counter that can be preset. An
increment of one unit in this number
represents a time change of 1/256 sec-
ond (about 4 milliseconds), so that
the 40-bit number represents the
number of 1/256 second intervals
that have elapsed since the computer
was permanently turned on. (Given
the above figures, a 40-bit number
will represent a time period of ap-
proximately 139 years.)
In keeping with the design philos-
ophy of burdening the 6502 micro-
processor with as few tasks as possi-
ble, the real-time clock was designed
to require the generating of as few in-
terrupts as possible. Another area of
memory contains a signed 23-bit
counter circuit that automatically
counts down to at a rate of one
count every 1/256 second. Normally,
when this timer reaches (once every
2 23 /256 seconds, or about 9 hours), it
generates an interrupt that adds the
same amount (about 9 hours) to the
40-bit clock number. However, if any
program needs to access the real-time
clock, the appropriate count based on
the value in the 23-bit counter can be
added to the 40-bit clock number and
the 23-bit counter can be cleared, thus
updating the clock to its correct
value.
Associated with the real-time clock
is an event queue in which future
events are stored as 40-bit numbers
along with instructions to be carried
out when the 40-bit clock number
reaches that value. Internally, the
operating system software can use
this event queue to manage a set of
asynchronous events with a mini-
mum of processing. Application pro-
grams can use the event queue, as can
users programming on the HHC.
Design for Component
Interaction
The Quasar /Panasonic HHC was
designed to be compatible with both
existing and future hardware and
software. Because of this, the mem-
ory usage of the computer had to be
planned to provide maximum flex-
ibility.
In most microcomputer systems,
there are fixed memory locations or
I/O (input /output) ports assigned for
specific hardware peripherals. The
limitation of this approach is that the
entire memory mapping must be fore-
seen; otherwise the ability to include
Data compression
techniques in the com-
puter almost double
the amount of Informa-
tion that can be stored
in a given number of
bits.
future peripherals is questionable.
The HHC does not make any fixed
assignments. Instead, 4 bytes for each
peripheral are dynamically assigned
as I/O and status locations for all cur-
rently connected peripherals each
time the clear key is pressed, so any
number of different peripheral types
can be accommodated without run-
ning into memory map conflicts.
This flexible system of directing in-
put and output allows the HHC to
offer a more commonsense approach
to dealing with devices like printers,
modems, LCD displays, and other
devices. In most computers, special
commands must be given to direct in-
put and output to specific devices,
and even then you may not be able to
distribute it to several devices. For ex-
ample, a special command, LPRINT,
must be used to get either the Radio
Shack TRS-80 or the Atari 400 or 800
to print information on their
associated printers, and it is impossi-
ble to get a program to print on both
the video display and the printer
without using both PRINT and
LPRINT statements. With some limit-
ations this can be done with the
Apple computer, but only with the
correct interface board and the
correct PR#N command.
The attitude taken by Friends Amis
is that you shouldn't have to
remember extra information (which is
often complicated by being condi-
tional on what the computer is cur-
rently doing). With the HHC com-
puter, the use of I/O devices can be
changed by pressing the I/O key and
enabling or disabling the appropriate
devices from a menu displayed by the
HHC. You can even, for example, in-
terrupt a running program to enable
the printer, and resume the program
without error; from that point on,
both the current display device (the
LCD display, color TV, or other
device) and the printer display
whatever the program tells them to.
This method allows HHC programs
to be independent of the I/O devices,
and it allows the use of future
peripherals with current software.
Application Software
The Panasonic/Quasar HHC in-
cludes several application programs
that are contained in the same built-in
read-only memory devices as the
operating system. These programs
implement a calculator, a clock/
secretary, and an electronic file sys-
tem and editor. Each of these pro-
grams is called from the primary
menu of the HHC.
The calculator program, when
selected, transforms the HHC into a
standard four-function calculator
that adds, subtracts, multiplies, and
divides. The calculator can store one
number and has keys to add to, sub-
tract from, clear, and recall memory.
It also has a percent key.
The clock/secretary uses the real-
time clock that knows the time of
day, the day of the week, and the
date (day, month, and year). A clock
option within the clock/secretary
allows the time and date to be dis-
played and continuously updated on
the LCD display window. Otherwise,
the clock/secretary can be used to
keep track of future events. You can
specify a time for the clock/secretary
to activate itself, and include an op-
tional reminder message. When that
time arrives, the HHC sounds a mu-
sical tune regardless of its current
task; you can then perform an "ac-
knowledge" operation and see the
message associated with the event.
The number of events and messages
that the clock /secretary can hold is
limited by the amount of program-
mable memory in the HHC.
The "memory bank" is the nick-
name of an electronic file system and
editor within the HHC. You can enter
lines (or records) of up to 80 char-
acters of ASCII information, group
them to make files, and modify and
list these files. Any file can be edited
with a powerful cursor-controlled
editor that allows insertion and dele-
tion of characters or lines at the cur-
rent cursor position. With the
SEARCH key, you can also retrieve
records from a file based on a char-
acter string to be matched.
Memory bank files can have any
number of records, with each record
holding up to 80 characters. The size
and number of files that can be stored
depends on the amount of program-
42 January 1981 © BYTE Publications Inc
mable memory in the HHC. The cur-
rent model of the HHC has somewhat
less than 1500 bytes of memory for
this purpose, but the amount of
memory in the HHC can be expanded
with a battery-powered 4 K-byte
memory extender peripheral. Future
models will accept more program-
mable memory in the form of cap-
sules that fit into the same sockets as
the read-only memory capsules.
The Extended HHC
The Quasar/Panasonic HHC,
when combined with its line of pe-
ripherals, has the ability to perform
any function that existing personal
computers do, while retaining the
characteristics and advantages of a
hand-held unit. The following sec-
tions describe two of the most in-
teresting peripherals — the color tele-
vision interface and the modem.
The color television interface is the
only peripheral that requires connec-
tion to an AC power line. But since
the interface is also connected to a
color TV, this is hardly a limitation.
Once the interface is connected, out-
put can be routed to the TV through
the use of the I/O key.
Through the color TV, the HHC
will display 16 lines of 32 characters
each. Characters can be displayed in
several combinations (orange or
green characters on black, or black
characters on either an orange or a
green background). Several kinds of
characters can be displayed: upper-
case and lowercase ASCII letters;
numbers and punctuation; graphics
patterns; and katakana characters (a
set of phonetic characters used by the
Japanese). All characters are created
in a 7 by 9 dot matrix.
The color TV interface offers two
modes of color graphics: 32 by 64 pix-
els, or 48 by 64 pixels. The interface
allows for black and eight colors
(red, blue, green, yellow, orange,
magenta, cyan, and buff).
The color TV interface contains a
built-in RF (radio-frequency) modu-
lator, as well as 1.5 K bytes of
dynamic memory organized as two
software-selectable screen images.
The connection from the interface to
the HHC is an interrupt-driven par-
allel connection.
The modem, which connects to the
HHC through an interrupt-driven
parallel interface, is acoustically
coupled to a standard telephone
handset (see photo 4). Its options —
O
©
1
1
X
6
4
1
O
Q
3
4
X
/ \ 6
\ / 7
7 / \
4 \ /
X
©
©
©
Figure 4: Partial solution of an eight-element permutation problem. Each of the boxes
in the first and last columns is filled in first. The solution of this problem is then finished
by the solution of two four-element permutations as given by the numbers on both sides
of the boxes marked X and Y.
110 or 300 bps (bits per second) data
transfer rate, full- or half-duplex
transmission, answer or originate
mode, number of start and stop bits,
and parity — are all selected by soft-
ware. In a daring departure from con-
ventional modems, the HHC modem
has no visible switches to set any of
its options. This forces the software
to control all the options and leaves
nothing for you to worry with (or set
incorrectly).
The HHC modem, like other HHC
peripherals, is responsible for supply-
ing standard input and output rou-
tines. (By using a uniform software
interface for all peripherals, the HHC
can be expected to work with periph-
erals that have not yet been
designed.) Since the modem can be
used in several ways, it is supplied
with a socket in which to place a pro-
gram capsule for a given application.
The first capsule to be produced for
the HHC modem is called 'Telecom-
puting" and it will allow the HHC to
be used as an intelligent remote ter-
minal that is connected, through the
modem, to a timesharing computer or
data base. The program can be used
with the small battery-operated
modem directly connected to the
HHC, in a hand-held configuration,
or the printer and TV can be used.
The telecomputing software can
use an automatic X-ON/X-OFF hand-
shaking with a host computer so that
you can regulate the rate of display to
your reading speed. This protocol is
supported by most popular networks
such as Micronet, The Source, and
Tymnet. When a printer is not con-
nected, you can review many lines of
previous interaction as they appear in
the LCD display, creating, in effect, a
virtual printout. Incoming lines
longer than the 26-character LCD
display are divided only at blanks.
This "word-wrap" feature, combined
with the review mode, assures
January 1981 © BYTE Publications Inc 43
readability with the 1-line display.
Background of the HHC
The HHC was developed as a result
of a unique union of Japanese and
American technology. Friends Amis,
with headquarters in San Francisco,
contributed the best of Silicon
Valley — a software-based systems ar-
chitecture, circuit design, a unique
operating system and SNAP lan-
guage. The company's founders, who
came from Atari Inc, were responsi-
ble for introducing the now widely
accepted consumer video games.
Friends Amis' first product was the
highly successful language translator
sold by Craig, Quasar, and
Panasonic; this product was quickly
followed by its point of information
display computer and the HHC
(hand-held computer).
Matsushita, the parent company of
Panasonic and Quasar, in Osaka,
Japan, brought its unparalleled
techniques of miniaturization, in-
dustrial design, quality assurance,
and the ultimate in highly
The HHC, through the
color television Inter-
face, can display 16
lines of 32 characters
each.
automated, high-volume, low-cost
manufacturing — areas in which Japan
has clearly outstripped the US in re-
cent years. Putting the best of both
worlds together has resulted in a
special product that could not have
been produced alone: the first hand-
held computer with bus architecture,
a powerful operating system, and a
fast 8-bit microprocessor.
Conclusions
•The Quasar and Panasonic HHCs
are certainly impressive first entries
into the new market of hand-held,
consumer-oriented computers. Great
emphasis has been placed on human
engineering. This is important for any
device marketed to the general
public, even more so when so many
functions are being placed into such a
small package.
•The HHC was designed as a basic
unit augmented by an extensive com-
plement of peripherals. This "de-
bundled" approach allows you to buy
only those peripherals you want, giv-
ing you a customized computer at
minimal cost.
• Several innovations in the HHC
computer allow it to have the power
of conventional personal computers
while retaining the portability of a
hand-held unit. The use of data com-
pression techniques and program cap-
sules enables very large amounts of
data to be contained within the hand-
held unit.
•The HHC is supplied with internal
application programs that include a
clock, an electronic secretary that
reminds you of future appointments,
and a file system for user data con-
tained completely within the pro-
grammable memory of the computer.
These are nice touches that add to the
utility of the computer.
A Fictional Hand-Held
Computer
Duncan's Minisec had been a
parting gift from Colin, and he was
not completely familiar with its
controls. There had been nothing
really wrong with his old unit, and
he had left it behind with some
regret; but the casing had become
stained and battle-scarred, and he
had to agree that it was not elegant
enough for Earth.
The 'Sec was the standard size of
all such units, determined by what
could fit comfortably in the nor-
mal human hand. At a quick
glance, it did not differ greatly
from one of the small electronic
calculators that had started coming
into general use in the late twen-
tieth century. It was, however,
infinitely more versatile, and
Duncan could not imagine how life
would be possible without it.
Because of the finite size of
clumsy human fingers, it had no
more controls than its ancestors of
three centuries earlier. There were
fifty neat little studs; each, how-
ever, had a virtually unlimited
number of functions, according to
the mode of operation — for the
character visible on each stud
changed according to the mode.
Thus on ALPHANUMERIC,
twenty-six of the studs bore the
letters of the alphabet, while ten
showed the digits zero to nine. On
MATH, the letters disappeared
from the alphabetical studs and
were replaced by X, +, +, — , =,
and all the standard mathematical
functions.
Another mode was DICTION-
ARY. The 'Sec stored over a hun-
dred thousand words, whose
three-line definitions could be
displayed on the bright little
screen, steadily rolling over page
by page if desired. CLOCK and
CALENDAR also used the screen
for display, but for dealing with
vast amounts of information it was
desirable to link the 'Sec to the
much larger screen of a standard
Comsole. This could be done
through the unit's optical inter-
face — a tiny Transmit-Receive
bull's-eye operating in the near
ultraviolet. As long as this lens was
in visual range of the correspond-
ing sensor on a Comsole, the two
units could happily exchange in-
formation at the rate of megabits
per second. Thus when the 'See's
own internal memory was satu-
rated, its contents could be
dumped into a larger store for per-
manent keeping; or conversely, it
could be loaded up through the op-
tical link with any special data re-
quired for a particular job.
From Imperial Earth, copyright
1976 by Arthur C Clarke.
Reprinted by permission of
Harcourt Brace Jovanovich Inc.
[Editor's Note: The 'Duncan' refer-
red to in the first paragraph is
Duncan Makenzie, the main char-
acter in Clarke's Imperial Earth.
Duncan's boyhood friend is Karl
Helmer, a character whose name is
a variant spelling on that of our
Founding Editor, Carl Helmers.
For a humorous (and somewhat
eerie) commentary on the name
similarity and the anticipated
possibility of a hand-held com-
puter, see Carl Helmers' editorial
in the April 1977 BYTE (page 6).
"How I Was Born 300 Years Ahead
of My Time. "]
44 January 1981 © BYTE Publications Inc
• The HHC retains the contents of
memory even when it is turned off. In
addition, you do not lose what you
are working on if you accidentally hit
the OFF button. These are important
features that indicate the amount and
depth of human engineering that has
been applied to the design of the
HHC.
• The HHC will be marketed
aggressively by both Quasar and
Panasonic. The public reaction to this
device, which is the first of its kind to
be marketed on such a large scale,
will be carefully observed by manu-
facturers and may determine the ex-
tent and direction of future consumer
products in this area. We feel that the
Panasonic/Quasar HHC is highly
qualified to receive this scrutiny and
that the public response will be
favorable. ■
Acknowledgment
The cover photograph and all interior
photographs are by Ed Crabtree. Photo 2 is
courtesy Quasar Electronics Company.
Another Pocket Computer
The internal architecture of the
TRS-80 Pocket Computer is radi-
cally different from the other
pocket computers now reaching
the market. Instead of a single 8-bit
microprocessor (such as that used
in the Quasar/ Panasonic HHC and
the Sinclair ZX-80), the designers
of the TRS-80 Pocket Computer
(Sharp Electronics of Japan) decid-
ed to use two 4-bit micro-
processors in a unique serial con-
figuration.
Both microprocessors are
custom CMOS (complementary
metal-oxide semiconductor) in-
tegrated circuits with built-in
ROM (read-only memory). The
purpose of microprocessor 1 is to
arrange data and make decisions.
It reads the data that is keyed in or
fetched from programmable
memory. It is also responsible for
parsing arithmetic operations and
interpreting the syntax of BASIC
statements. It then arranges the
data and provides instruction
codes to microprocessor 2 through
a transfer buffer. The actual execu-
tion of an instruction is performed
by microprocessor 2, which also
updates the display and notifies
microprocessor 1 that it has finish-
ed its function. The respective
duties of the microprocessors are
listed at right.
Memory Organization
The programmable memory of
the TRS-80 Pocket Computer is
contained in four integrated cir-
cuits. There are three memory ICs,
each containing 512 bytes of pro-
grammable memory. The three ICs
which drive the liquid-crystal dis-
play each contain 128 bytes of pro-
grammable memory. Putting it all
together, you end up with 1920
bytes of programmable memory.
After you subtract memory space
used for the transfer buffer, input
buffer, display buffer, fixed mem-
Microprocessor 1
Microprocessor 2
Key input routine
Acknowledgment of the
Display processing routine
Input buffer
Computational result
remaining program
Error
One instruction to one
Arithmetic routine
program step incorporation
Character generator
Interpreter:
Program execute statement
Cassette routine
Cassette control statement
Command statement
Print routine
Printer control (reserved)
Buzzer
Execution of manual
Recognition of printer
operation
(reserved)
Power shut-off control
Power off
Clock stop control
Clock stop
ories, and reserved keys, you end
up with 1424 bytes of user-address-
able memory. Into this space you
can easily fit a BASIC program of
around 250 lines (average
length)... SMm
January 1981 © BYTE Publications Inc 45
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Circle 24 on inquiry card.
FLUK
Ciarcia's Circuit Cellar
Electromagnetic Interference
Steve Garcia
POB 582
Glastonbury CT 06033
You may have noticed that certain
household appliances such as a
microwave oven or tools such as a
power saw affect television reception
Copyright © 1 98 1 by Steven A Ciarcia.
All rights reserved.
when they are running. This televi-
sion interference, or TVI, is caused by
the electromagnetic energy which is
radiated when these electrical devices
are in use. The general term used to
describe such noise is EMI (elec-
tromagnetic interference).
EMI emanates from both natural
and artificial sources. Natural ter-
restrial EMI sources include lightning
discharges, precipitation, and storms.
Man-made EMI can come from
electrical-power systems, rotating
electrical machinery, gaseous-
discharge systems, and electronic
equipment such as radar, computers,
Photo la: To illustrate the effects of radiated and coupled interference, a portable TV set is placed next to an operating TRS-80 Model
I computer. The result is a very snowy picture, primarily the result of radiated noise. Also note a slight blurring of the characters on
the TRS-80 display screen. A beat frequency caused by magnetic coupling between the two video displays causes the TRS-80 screen
image to shake. In a longer exposure, the characters would be illegible.
48 January 1981 © BYTE Publications Inc
and television transmitters. Natural
EMI is usually beyond man's control,
and attempts to reduce it must be
centered on the susceptible equip-
ment. Man-made EMI, on the other
hand, can be suppressed at the
source — this is the most satisfactory
way to eliminate interference.
Various forms of EMI are a major
concern today due to the rapid
growth of digital electronic process-
ing in business, industrial, and home
environments. My mail has been
overflowing with questions on
computer-related interference. The
letters have been almost evenly divid-
ed between readers who require help
in cutting down the EMI emitted from
their computers and those concerned
with their computers' own suscep-
tibility to noise.
The problem has received con-
siderable news coverage lately, due to
the FCC's (Federal Communications
Commission's) stepping in to regulate
noise emissions from personal com-
The relative effect of
capacftfve coupling of
noise Is dependent
upon the distance
between conductors.
puters and other electronic equip-
ment. In the past, only equipment in-
tended for certain military applica-
tions had to meet EMI limitations.
The few EMI filters that were in-
stalled were primarily intended to
protect the equipment in which the
filters resided from the effects of EMI
generated by external sources, enter-
ing through the AC (alternating cur-
rent) power lines.
Little if any thought was given to
attenuating electrical noise which was
generated within the equipment, leak-
ing out through a variety of coupling
paths. Because of the large volume of
complaints about EMI that have
reached the FCC, the Commission
has set new regulations on the max-
imum level of electrical noise that can
be emitted from electronic equip-
ment. These regulations took effect
on January 1, 1981. (See "FCC
Regulation of Personal- and Home-
Computing Devices" by Terry G
Mahn, September 1980 BYTE, page
180.)
But what about the equipment you
own now? What if you have an im-
mediate noise problem? Where do
you start to solve the problem? How
do you detect where the noise is com-
ing from7 How do you break the path
between the noise source and the af-
fected receiver? Should you put noise
filters on every electrical outlet in the
house? How does shielding work?
Answering all these questions
could easily fill a book. However,
because EMI is such a pressing prob-
Photo lb: Demonstration of the effects of shielding. We have added a line filter to eliminate conductive interference to the setup of
photo la. In addition, two grounded copper sheets, one under the portable TV set and one to the left of it against the side of the
TRS-80 video monitor, protect the TV set from radiated noise. The results can be seen as greatly improved picture quality.
January 1981 © BYTE Publications Inc. 49
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The three forms of
noise coupling are con-
ductive, common-
impedance, and
radiated-field coupling.
lem for many computer owners, I
think it needs to be addressed
nonetheless.
This article is intended as an in-
troduction. While not endeavoring to
cover all sources and solutions, it will
outline the common causes and paths
of noise and suggest possible methods
for controlling interference. For that
reason, I am not limiting the discus-
sion merely to computer-generated
EMI and related suppression
methods. I hope the result will be a
better understanding of the entire
problem.
First, a few definitions:
• Noise: any electrical signal present
in a circuit other than the desired
signal.
• Noise Path: the coupling medium
that conducts the noise from the
source to the receiver.
• Interference: the undesirable effect
of noise.
• Susceptibility: the capability of a
device or circuit to respond to un-
wanted electrical noise.
• Receiver: any circuit or device be-
ing affected by interference.
If you own a typical computer pur-
chased before the FCC regulations
went into effect, then you no doubt
have noticed that it emits con-
siderable EMI. Depending upon the
manufacturer and configuration of
the system, the extent of the noise
may range from a little extra fuzziness
in television pictures to an actual
blackout of TV reception. The effect
upon nearby television sets is depen-
dent upon the level of the emitted
noise, the susceptibility of the
receiver, and the coupling channel
which conducts the noise from the
source to the receiver.
Noise Coupling
In order for noise to be a problem,
there must be a noise source, a re-
ceiver that is susceptible to the noise,
and a coupling channel that transmits
the noise to the receiver. The relation-
ship is shown in figure la.
We start to analyze a noise prob-
50 January 1981 © BYTE Publications Inc
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t Apple is a trademark of Apple Computer Inc.
tTRS-80 is a trademark of Radio Shack, a division of Tandy Corp.
lem by defining what the noise source
is, what the receiver is, and how the
source and receiver are coupled
together. It follows that there are
three ways to break the path:
1. The noise can be suppressed at the
source.
2. The receiver can be made insen-
sitive to the noise.
3. The amount of energy leaking
through the coupling channel can be
minimized.
There are three forms of noise
coupling: conductive, common-
impedance, and radiated-field cou-
pling. Figure lb demonstrates a
typical situation. In this circuit, the
commutator noise generated from the
Photo 2: The simplest method of noise reduction is to use capacitors as simple filters.
This photo shows two 0.1 fiF, 1000 V capacitors used to filter the AC power line in a
video terminal.
motor is both conducted along and
radiated from the leads going to the
motor-control circuit. Also, the
motor control and the television
receiving set are plugged into the
same long extension cord, so they
share a common line impedance. The
coupling channel consists of:
• conduction on the motor power-
supply leads
• radiation from the leads
• common line impedance
To eliminate the motor's influence on
the TV, all three parts of the coupling
path must be broken. You can apply
EMI controls to any or all of these
elements.
Conductive Coupling
Conductively coupled noise is
often overlooked. A wire passing
through a noisy environment picks
up noise either by capacitive or
magnetic coupling and conducts it to
another circuit. A simple representa-
tion of capacitive coupling between
two conductors is shown in figure 2.
When the resistance from conductor 2
to ground, R, is large, the voltage
coupled from conductor 1 to conduc-
tor 2 is defined as follows:
V N =
\ c a + C 2C J
v,
Photo 3: Commercial power-line filters from Corcom Inc, 2635 North Kildare Ave,
Chicago IL 60639. Prices range from $10 to $20.
where C 12 is the stray capacitance bet-
ween conductors 1 and 2, C iC is the
capacitance between conductor 1 and
ground, C 2C is the capacitance be-
tween conductor 2 and ground, R is
the resistance from conductor 2 to
ground, V, is the interfering voltage,
and Vat is the noise voltage produced
on conductor 2.
Even though this may appear small
(perhaps a few microvolts),
remember that some receivers
amplify input signals thousands of
times. A few microvolts of noise on
the antenna terminals of a television
set could easily be greater than the
desired video signal.
Figure 3 shows the effect of conduc-
tor spacing on capacitive coupling.
The coupling factor is said to be dB
(decibels) when the two conductors
are separated by a distance equal to
three times the conductor diameter
(for 22-gauge wire, d = 0.71 mm or
about 0.028 inches); the factor
decreases rapidly as the spacing in-
creases. Separating wires reduces the
capacitive coupling between them.
However, little is gained by spacing
52 January 1981 © BYTE Publications Inc
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NOISE
SOURCE
COUPLING
CHANNEL
RECEIVER
Figure la: The general case of the transmission of electrical noise.
AC POWER LINE
(TELEVISION SET)
Figure lb: A typical noise-coupling situation: commutator noise generated by the motor
is conducted along and radiated from the connecting leads. Common line impedance
shared by the receiver (a television set) and the motor cause motor noise to be imposed
on the receiver's power input.
Ct2=stray capacitance between
conductors 1 and 2
C ic = capacitance between conductor
1 and ground
Cic — capacitance between conductor
2 and ground
R = resistance from conductor 2 to
ground
Vi ^interfering voltage
V N =noise voltage produced on
conductor 2.
CONDUCTORS
Figure 2: Representation of capacitive coupling between two conductors. The defini-
tions of the symbols are listed above.
1/8 1/4 1/2
SEPARATION D FOR 22-GAUGE WIRE (INCHES)
1 11/2 2 2 1/2 3
-2
-4
-6
-8
-10
-12
Figure 3: The relative effect of capacitive coupling of noise is dependent upon the
distance between conductors. In the chart shown, for 22-gauge wire, coupling is signifi-
cant only when the conductors are closer together than 25 mm (1 inch).
the conductors more than 40
diameters apart (about 25 mm or 1
inch).
Magnetic Coupling
Magnetic coupling is also a prob-
lem. When a current flows in a closed
circuit, it produces a magnetic flux
which is proportional to the current.
If two wires are parallel, the flux pro-
duced in one wire will induce a
voltage in the second wire. This in-
duced voltage constitutes noise.
When you are running wires between
sensitive electronic components,
avoid laying signal wires parallel to
noisy, high-current AC power lines.
If a signal line must cross a power
line, have it do so at a right angle.
Common-Impedance Coupling
Common-impedance coupling oc-
curs when currents from two different
circuits flow through a common im-
pedance. Two examples of this type
of coupling are shown in figures 4 and
5. In figure 4, the ground currents of
both circuits flow through a common
ground impedance. The ground
potential of circuit 1 is modulated by
circuit 2, and vice versa. Any fluctua-
tions in the ground current of circuit 2
will be coupled through the ground
impedance, X c , to circuit 1.
Another example is the power-
distribution schematic diagram
shown in figure 5. Any change in the
current required by circuit 2 will af-
fect the voltage at the terminals of cir-
cuit 1. This effect is due to the com-
mon impedance of the power-supply
lines and internal source impedance,
R Sl of the power supply. Shorter
leads will help reduce the line im-
pedance, but the source impedance
always remains. The typical com-
puter system plagued with common-
impedance noise is one where the
builder has attempted to use the pro-
cessor power supply to run
everything, including peripherals.
The apparent economy is outweighed
by periodic system crashes and un-
predictable errors.
Radiated-Field Coupling
Radiated electric and magnetic
fields provide the last form of cou-
pling. This form of coupling can be
most easily thought of as free-air
radio transmission. The interfering
circuit broadcasts noise just like a
radio station, and every conductive
surface in the receiver acts as an
antenna. At close distances, the noise
can in fact be much stronger than a
real radio station. [Many readers
54 January 1981 © BYTE Publications Inc
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Nowavailable for TM990/189 module.
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With the TM990/469 Basic ROM kit,
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When purchased separately, the
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Of course, the standard TM990/189 is
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• IK byte RAM expandable to 2K
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A 570-page tutorial text accompa-
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Order your University Module from
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© 1980 Texas Instruments Incorporated
Circle 28 on inquiry card.
Texas Instruments
INCORPORATED
CIRCUIT 1
CIRCUIT 2
GROUND VOLTAGE
OF CIRCUIT 1
I
I
A?
GROUND CURRENT
l2G
/77
"GROUND CURRENT
llG
COMMON GROUND
IMPEDANCE
GROUND VOLTAGE
OF CIRCUIT 2
fh
Figure 4: Common-ground-impedance coupling is caused by two pieces of equipment using the same electrical lead to ground. The
ground current of one influences the ground-reference voltage of the other, and vice versa. One solution to this is a single-point
grounding system.
probably know of methods for
generating computer music by using
an AM radio to pick up computer-
emitted noise while the appropriate
program runs... RSS]
The characteristics of a field are
determined by the source of the field
and the distance between the source
and the point of observation. When
the receiver is near-field, closer than
1 / 6 wavelength, the electric and
magnetic fields are considered
separately. Any source/receiver
distance greater than V 6 wavelength
is far-field, and the electric and
magnetic fields are considered
together and are called simply the
electromagnetic field.
At frequencies below 1 MHz, most
coupling is near-field, because the
near-field boundary at the corre-
sponding wavelengths extends out to
approximately 45 meters (150 feet) or
more. At 100 MHz, most coupling is
far-field. For purposes of this discus-
sion, however, radiated-field-
interference problems within any
given piece of equipment should be
considered to be caused by near-field
radiation unless the interference is
clearly from far-field radiation.
Finding and Fixing
a Noise Problem
The key to solving a noise problem
is finding the source of the noise. In
fact, your computer might not be the
culprit. More than one computer
owner has suffered complaints about
his "computerized noise generator"
only to later find that the real source
of the interference was the solid-state
light dimmer on the overhead light.
Continuous sources of noise are
easier to identify than intermittent
ones. The interference from ap-
pliances and computers is usually
broadband, affecting the entire radio-
frequency spectrum. Digital
waveforms are especially rich in har-
_ — SOURCE IMPEDANCE
'l + l2
^i_^
*s
, . -
CIRCUIT1
<T
COMMON LINE
IMPEDANCES
POWER
SOURCE
^2
CIRCUIT 2
Figure 5: Common-power-source coupling occurs within a computer that uses a single
power supply for multiple peripheral devices. Due to the impedances on the connecting
lines, the current drawn by one circuit changes the voltage "seen" by another circuit.
monic frequencies, as shown in figure
6. Therefore, the continuous,
harmonic-rich emissions of com-
puters are relatively easy to find.
A standard battery-operated AM
radio makes a good EMl detector.
With it tuned to a frequency at which
the noise is the loudest, just roam
around the house looking for the
place where the interference is the
strongest.
If you suspect the computer, then
move the radio around it and along
the connecting cables. You will be
surprised how much the cables con-
tribute to radiated noise. Disconnect
cables and peripheral devices selec-
tively to further isolate interference
sources. Often, the long leads be-
tween the computer and printer emit
electromagnetic radiation as well as
any transmitting antenna you could
have possibly designed.
Finally, move the radio along the
power cord you have supplying the
computer system. If you are using a
15-meter (50-foot) extension cord
without the ground lead connected,
shortening the cord will reduce radia-
tion considerably.
If the computer system is indeed
found to be the source of the in-
terference, there are a variety of
possible coupling paths. The coupling
efficiency of digital interference is
proportional to frequency; the higher
the frequency, the greater the in-
terference. Depending upon the
design, these interfering signals can
radiate from the source, couple from
line to line, or be conducted directly
through connecting wires to the exter-
nal environment. Each noise path
must be suppressed.
Grounding
Grounding is the primary way to
56 January 1981 © BYTE Publications Inc
Circle 29 on inquiry card.
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minimize unwanted noise and
pickup. It is often the optimal solu-
tion to most problems. There are two
basic objectives in designing proper
grounding systems. The first is to
minimize the noise voltage generated
by currents from two or more circuits
flowing through a common ground
impedance; the second is to avoid
creating ground loops which are
susceptible to magnetic fields and dif-
ferences in ground potential. This
ground is the reference point for all
voltages in the system.
Signal grounds are generally
classified as either single-point or
Photo 4: Switching-type power supplies, which use high-frequency pulse-width-
modulated waveforms, are a potential source of noise. Most often they are contained in
shielded enclosures, as in the Apple II, to eliminate possibly interfering radiation.
Photo 5: The Atari 400 and Atari 800 personal computers are designed to eliminate any
forms of EMI coupling and to meet the new FCC standards. This requires considerable
shielding. The high-frequency processor and memory sections of the printed-circuit
board are segregated from the power supply and I/O (input/ output) areas. A heavy-
gauge aluminum enclosure encircles the high-frequency sections, as shown in this Atari
800.
58 January 1981 © BYTE Publications Inc
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Up to date patient information available anytime.
Patient files are updated everytime a transaction is
entered. All you need to check their files is to enter
the patient's name — no ID number.
PRIVATE AND THIRD PARTY BILLING
System keeps track of third party billing and insur-
ance claims. You can bill the patient on paper while
they are in the office! Resubmission of a claim is as
simple as pushing a button.
TECHNICAL SPECIFICATIONS
Written in Pascal, the system runs on most any 56K or 64K micro or mini computer. The system is currently operating
on Dynabyte, Cromemco, Onyx, Vector Graphic, and Digital Equipment Corporation (DEC) computers. Different
systems provide 500 to 10,000+ patient capacity.
Contact your Local computer store or
Circle 31 on inquiry card.
PROFESSIONAL
BUSINESS
SOFTWARE
119 Fremont Street, San Francisco, CA 94105, (415) 546-1596
multipoint grounds. From a noise-
reduction point of view, the single-
point ground is more desirable. Nor-
mally, with equipment operating at
frequencies below 1 MHz, a single-
point system is used. Above 10 MHz,
a multipoint ground is best, to
minimize ground impedance. Be-
tween these bounds, the type of
grounding depends on the system
configuration and layout. For per-
sonal computers, single-point
grounding is advised.
The AC power ground is of little
practical value as a signal ground. It
is usually connected to signal ground
as a safety measure only.
Shielding
When properly used, shielding is
an effective means of reducing the
coupling of noise between conduc-
tors. Shields consist of a variety of
conductive materials (usually steel,
copper, or aluminum), all of which
serve in some way to reflect, absorb,
or otherwise channel noise currents
away from the protected conductor.
Shields may be placed around com-
ponents, circuits, complete
assemblies, cables, or transmission
lines.
A parallel-tuned trap
cannot be used for
broadband computer-
generated noise.
The best way to minimize radiated
noise and susceptibility on connecting
wires is to use coaxial cable (coax) or
shielded twisted-pair cabling between
peripheral devices and the processor.
If the coaxial-cable shield is grounded
at one end, it will protect the central
conductor from electric-field radia-
tion. Grounding the shield at both
ends creates a return current in the
shield, which generates a field that
cancels the conductor's electric field
and any magnetic interference as
well.
In twisted-pair shielded wire,
grounding the shield at one end takes
care of electric fields, while twisting
the conductor with the return line
serves to reduce magnetic suscep-
tibility. (Twisted-pair shielded wire is
especially useful on low-level
signals.) The number of twists per
foot determines the insensitivity to
ARTIFICIAL
INTELLIGENCE
C/PM®
For Your
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S-100 SYSTEM
"SHIVA'"" is a highly-sophisticated VIRTUAL-PERSONALITY™ multi-level multi-
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surprisingly little R.A.M. area, and is conversational!!! SHIVA's™ English-like
input/output is interactive, dynamic, and may be reconfigured or expanded by the
user. And SHIVA'" gives you the freedom to expand indefinitely . . . with tremendous
hardware and software choice: SHIVA™ supports hard disks and floppies . . . R.A.M.
addressing beyond 64 kilobytes . . . time-sharing . . . multi-level user-reconfigurable
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SHIVA'" is compatible with C/PM® and C/DOS® for easy implementation and near
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And Omega Research™ is dedicated to non-obsolescence and system superiority in
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SHIVA™ $350 - Available on 8" I.B.M. Soft-Sectored Disks and 5" C/DOS®
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"SHIVA 1 "," "VIRTUAL-PERSONALITY'"." and "OMEGA RESEARCH 1 "" are trademarks of OMEGA RESEARCH.
"RT-11 ■ " in a trademark of DIGITAL EQUIPMENT CORPORATION.
"UNIX"" is a trademark of BELL Ij\BORATORIES
"CP/M-" is a trademark of DIGITAL RESEARCH OF CALIFORNIA
"C/DOS-" is a trademark of CROMEMCO. Inc.
"Z-80" " and "Z-8000" are trademarks of ZILOG. Inc.
"INTEL- " is a trademark of INTEL CORPORATION
No shipments prior to return of signed software
license agreement. For detailed information on
"SHIVA™," send $1.00 postage and handling to: A— »\ P0 - Box 479
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(209) 334-6666
9am to 5pm Mon.-Fri.
CALIFORNIA RESIDENTS ADD 6% SALES TAX
magnetic fields.
When comparing coaxial cable and
shielded twisted-pair cable, it is im-
portant to recognize their differences
in signal propagation, irrespective of
their shielding characteristics. Shield-
ed twisted-pair cable is very useful at
frequencies below 100 kHz. Above 1
MHz the signal losses are con-
siderable.
Coaxial cable, grounded at one
end, provides a good degree of pro-
tection from capacitive pickup and
can be used at all frequencies from
DC (direct current) to UHF (ultra-
high frequencies). However, due to
the potential for noise currents to
flow through the shield (which is also
part of the signal path), coaxial cable
is better used at higher frequencies
where such errors are minimized.
Shielded twisted-pair cable, on the
other hand, does not exhibit this
problem and should be used for con-
ducting low-frequency signals.
An unshielded twisted pair, unless
it is balanced, provides very little
protection from capacitive pickup,
but can still be good for magnetic-
field protection. Plain untwisted-pair
cable, such as the zip cord you might
purchase from a hardware store, pro-
vides no electromagnetic-field protec-
tion and should be avoided if you
have a noise problem.
Multiple-conductor cables, in-
cluding ribbon cables, are also
available in twisted-pair configura-
tions. A common cable used in data
acquisition is a twelve-conductor
shielded cable that consists of six
twisted pairs surrounded by a single
foil or braided shield. This cable is
very expensive, however, and it is
best acquired on the surplus market.
Shielding the connecting cables
may eliminate only part of the prob-
lem, especially if you determine that
the major source of radiation is the
computer. Most computers are en-
cased in metal chassis. If these are not
properly grounded, the benefits of the
metal as shielding material are lost.
On the other hand, if the computer
is encased in plastic, the only solution
is to coat the inside (or the outside) of
the case with a conductive substance
and connect it to signal ground.
Aluminum foil, for example, could be
used, but I suggest that you try all the
other suppression measures before at-
tempting this.
Encasing the entire computer in a
conductive enclosure is not un-
thinkable. In fact, newer small com-
puters such as the Atari 800 and
Hewlett-Packard HP-85 are built ex-
60 January 1981 © BYTE Publications Inc
Circle 32 on inquiry card.
Circle 33 on inquiry card.
When It Comes
To Add-on Memory...
LOBO
Has It All.
LOBO DRIVES manufactures a full line of S-1 00
computer compatible disk drives. All drives are
software compatible with most S-1 00 disk operating
systems and applications software programs. Only
LOBO DRIVES offers you the variety and choice of
floppy and fixed disk drives. Choose from 5'/a and
8-inch floppies, 5'/« and 8-inch Winchester technology
fixed disk drives, and several Floppy/Fixed disk
combinations. Each LOBO DRIVES system is
thoroughly tested and burned-in and has the famous
LOBO DRIVES One Year, 100% Parts/Labor
Warranty.
MODEL 400 5V4-INCH FLOPPY
DISK MEMORY SYSTEM
A high-speed (298) Msec Access), high-
reliability (8000 hrs MTBF), low-cost floppy
disk memory system. It is available in both
soft and hard sector formats, and a choice
of single or double density configurations.
• Up to 220 KBytes Capacity
• Single/Double Density
• Soft Sector Format
• Complete Software Compatibility
MODEL 800/850 DUAL FLOPPY
DISK DRIVE MEMORY SYSTEM
LOBO DRIVES offers you a choice of
single-sided, single or double density
(Model 800) or double-sided, single or
double density (Model 850) dual 8-inch
memory subsystems. Each system comes
complete with chassis and power supply,
cables, controller and interface.
• Compatible with Most S-1 00 DOS
Systems
• Up to 3.2 MByte Capacity
MODEL 1850 DUAL
FLOPPY/FIXED DISK MEMORY
SYSTEM
No more worries about back-up. LOBO
DRIVES has combined the latest state-of-
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850 8-inch floppy disk drive to bring you the
ultimate in memory expansion for your
S-1 00 computer. The Model 1850 is the
ideal memory system for small business
and word processing applications.
• 5 or 10 MByte Fixed Disk Capacity
• 1 .6 MByte Floppy Disk Capacity
• Software Compatibility
• Sealed Environment
• Winchester Reliability
• 70 Msec Average Access Time
MODEL 950 DUAL
FLOPPY/FIXED DISK MEMORY
SYSTEM
All the advantages of Winchester
technology fixed disk memory: large
capacity (6.38 MBytes), high speed (170
Msec avg. access time), and extended
reliability, combined with the convenience
of a built-in floppy disk back-up in one
cabinet. Only LOBO can bring you the
storage capacity of 1 6 mini-floppies at a
fraction of the price.
• The Storage Capacity of 16 Mini-
Floppies
• Built-in Back-up
• 1 70 Msec Access (Avg)
• Software Compatibility
See your nearest dealer, call, or write for the complete LOBO DRIVES story,
find out just how competitively priced a quality drive can be.
"clrii/es
I
I N T E R l\J AT I O M A L
935 Camino Del Sur
Goleta, California 93017
(805) 685-4546
Telex: 658 482
Circle 34 on inquiry card.
PERSONAL
COMPUTER
SYSTEMS
[cippkz computer
Sales and Service
w*!W*
APPLE II, 16K, List $1195 $ 989
32K, List $1395 $1169
48K 1259
ATARI® 400™, List $630
OUR PRICE ONLY $499
820 PRINTER, List $599.95 $499
810 DISK DRIVE, List $699.95 $589
only $2799
• Extended BASIC Language
• Advance Graphics
• CRT Built-in Display
• Magnetic Tape Cartridge for Storage
CALCULATORS BY
Wk'JM HEWLETT
W!HM PACKARD
HP-41C Calculator, "A System" . .
$244.95
HP-32E Scientific w/Statistics . . .
$ 53.95
HP-33C Scientific Programmable .
. 99.95
HP-34C Advanced Scientific
Programmable
123.95
HP-37E Business Calculator
. 58.95
HP-67 Handheld Fully Advanced
Programmable Scientific for
Business &■ Engineering
298.95
HP-97 Desktop w/Built-in Printer . .
579.95
COMMODORE PET Call for Prices
Prices do not include shipping by UPS. All
prices and offers are subject to change without
notice.
R
ersonal
omputer
ystcms
c
map
s
609 Butternut Street
Syracuse, N.Y. 13208
(315) 478-6800
62 January 1981 © BYTE Publications tnc
actly that way. It is very effective in
both containing the computer's elec-
tromagnetic fields and protecting the
computer circuitry from external
noise. When an EMI field impinges on
a shield, some of its energy is
reflected at the first surface, some is
absorbed by the shield material, some
is reflected by the second surface, and
some passes through. In general the
following is true of enclosure-type
shielding:
• Magnetic fields are harder to shield
against than electric fields. Magnetic
material should be used to shield
against low-frequency magnetic
fields.
• At high frequencies, a good conduc-
tor suitably shields against both elec-
Summary of Noise-Reduction Techniques
Suppressing noise at the source:
4. Keep ground leads as short as
possible.
1. Enclose noisy sources in a
5. Separate noisy and quiet leads.
shielded enclosure.
6. Use a single-point grounding
2. Filter all leads leaving a noisy
system.
environment.
7. Avoid ground loops.
3. Shield and twist noisy leads.
8. Keep sensitive-signal leads as
4. Ground both ends of coaxial-
short as possible.
cable shields to suppress radiated
interference.
Reducing noise at the receiver:
5. Limit pulse-rise times where
possible.
1. Use frequency-selective filters
where applicable.
Eliminating noise coupling:
2. Use shielded enclosures for sen-
sitive circuitry.
1. Twist and shield signal leads.
3. Provide proper power-supply
2. Ground shielded leads used to
filtering.
protect low-level signals at one end
4. Separate signal and hardware
only.
grounds.
3. Avoid ground leads in common
5. Use shielded cables to protect
between high-level and low-level
low-level signals.
equipment.
Photo 6: The underside of an Atari 800. Metal plates enclose the processor and
memory. The green printed-circuit board on the lower left contains the keyboard cir-
cuit. Since it runs at low frequencies, it does not require a shielded enclosure.
Circle 35 on inquiry card. — ►
NOW CLEANING YOUR OWN
DISKETTE HEADS COULD SAVE
YOU A $ 40 SERVICE CALL.
AND A LOT MORE.
The recording heads on your
diskette drives may be dirty —
and that can cause you a lot of
grief. There's the serviceman
you have to call when the
machine doesn't perform. (You
know how much service calls
cost these days!) There's
machine down-time. Idle data
entry clerks. All the other delays
a cranky machine can cause.
And that service call might
not even be necessary.
3M solves the problem
in seconds-and leaves
your heads
"Computer Room Clean'!
The Scotch* head-cleaning
diskette kit lets you clean the
read-write heads on your
8" or 5 1 /4" diskette drives. In just
30 seconds, without any
disassembly, mess or bother,
the heads can be completely
cleansed of dirt, dust, magnetic
oxides-all the things that can
get into your machines every
day. And foul them up.
Just saturate the special
white cleaning pad in its jacket
with the cleaning solution. Then
insert the jacket into the disk-
ette drive and turn it on. Your
machine does the rest. The
heads are microscopically cleaned
without wear, without abrasion.
This 3M head-cleaning
diskette kit has been evaluated
and approved by major diskette
drive manufacturers. It's the
best possible way to clean your
heads without service calls or
machine teardowns.
At only $1 per cleaning-
it's the best insurance you
can get.
This fast-cleaning new Scotch
kit comes with everything
you need (including special
fluid, applicator tip, cleaning
diskettes) to handle up to
30 cleanings. That's only about
a dollar a cleaning.
With the Scotch head-clean-
ing diskette kit, you could save
yourself a lot more than just a
service call. So try this remark-
able kit today. For the name of
J
otct
oc
i
cleaning
1
"1
HIV!
is?"
CUAJfn
PSr '
1 ^
i
*
■ J
A Scotch cleaning diskette shown
before use, and after 15 cleanings
of recording heads.
the dealer nearest you, call toll
free: 800-328-1300.
(In Minnesota, call collect:
612-736-9625.) Ask for the
Data Recording Products
Division.
Circle 36 on inquiry card.
CP/A
OPTIMIZED SYSTEMS
SOFTWARE
PRESENTS
CONTROL PROGRAM/APPLE
the DOS you have been waiting for
OSS CP/A is an all new, disk-based
operating system which provides
commands and utilities similar to
CP/M". CP/A has byte and block I/O, a
simple assembly language interface,
and direct access via Note and Point.
And it's easy to add your own com-
mands or device handlers. CP/A is
expandable, flexible, consistent,
easy-to-use and available now with
compatible program products:
BASIC — Some of the features of OSS
BASIC are syntax checking on program
entry, true decimal arithmetic (great for
money applications), 32K byte string sizes,
flexible I/O, long variable names (up to 255
significant characters), and the ability to get
and put single bytes.
BUSINESS BASIC WITH PRINT USING —
This is virtually the only basic available on
the Apple that has PRINT USING. It also
has record I/O statements and all the
features of our standard BASIC.
EDITOR/ASSEMBLER/DEBUG — OSS
EASMD is a total machine language de-
velopment package. The editor provides
functions like FIND, REPLACE, etc. The
assembler uses standard 6502 mnemon-
ics, can include multiple files in one assem-
bly, and can place the object code in
memory or to a disk file.
Prices of CP/A with:
BASIC $ 69.95
Business BASIC 84.95
EASMD 69.95
BASIC + EASMD 1 09.95
Business BASIC + EASMD .... 124.95
Requires 48K RAM and DISK
Add $3.50 for shipping and handling in continental USA.
California residents add 6%. VISA/Master Charge wel-
come. Personal checks require two weeks to clear.
SEE YOUR DEALER or ORDER TODAY
OPTIMIZED SYSTEMS SOFTWARE
Is a product of
Shepardson Microsystems, Inc.
20395 Pacifica Dr., Suite 108B
Cupertino, CA 95014 '
(408) 257-9900
CP/M is a registered trademark of Digital Research
trie and magnetic fields.
• Shielding effectiveness is increased
with thicker shielding material.
• In practice, actual shielding effec-
tiveness obtained is determined by
the leakage through seams and joints,
not by the shielding effectiveness of
the material.
Filtering
Grounding and shielding were
prescribed to eliminate noise at the
source. The final measure, filtering, is
applicable either at the source or at
the receiver. Filtering is generally the
easiest form of noise abatement. It is
primarily used to reduce noise con-
Photo 7: The Atari computers allow the user to plug in special game and business pro-
gram cartridges. These ROM packs (read-only-memory modules), which are connected
directly to the processor bus, must also be kept within the shield when the computer is
running. This is accomplished using a special molded, %-inch (9.5 mm)-thick socket that
is electrically part of the shield. A plate of aluminum with conductive gasket material
around the edges is attached to the cover. When the cover is closed, the memory is com-
pletely shielded and virtually no electrical noise is emitted.
Photo 8: To reduce any high-frequency harmonics that might radiate from the video-
monitor cable, a toroidal ferrite core may be wrapped in the line.
64 January 1981 © BYTE Publications Inc
Circle 37 on inquiry card.
from
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The ACE 64K Distributed Process-
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serial I/O. Shared storage is pro-
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simply inserting additional DPCs
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+ CP/M is a registered TM of Digital Research, Inc.
Whatever your requirements, Whatever your language. No matter
how you say it — DISCOVERY is THE World Class Multiprocessor.
The ACE DISCOVERY MULTIPROCESSOR dedi-
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Multiuser mainframes with 192K ram start at
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(a)
FUNDAMENTAL
FUNDAMENTAL AND 3RD HARMONIC
FUNDAMENTAL, 3RD, AND 5TH HARMONICS
(b)
4V/jr
I , I , I
123456 789
HARMONICS
Figure 6: Within the computer and be-
tween peripherals, signals are digital. (6a)
Such signals are square waves with very
fast rise times, composed of the fun-
damental frequency, u, and all the odd
harmonics of the fundamental frequency.
In a computer with a clock frequency of 8
MHz, there will be radiated noise at 8
MHz, 24 MHz, 40 MHz, etc. (6b) The
amplitude becomes less at each higher
harmonic.
f(t) = l^sin wt + ^sin 3o)f + §^sin 5u>f + |^sin 7a>t +
7r 3tt ot fw
AC LINE
Figure 7: A simple low-pass line filter with homemade inductors.
-3/4 in.-
1
1/2 in., 12.7 mm
10 TURNS
NUMBER 16 WIRE
FOR L
duction into or out of the AC power
lines.
A circuit used as a power-line filter
is a low-pass filter ideally designed to
supress all frequencies above 60 Hz.
Such filters are commercially
available from many sources but are
also easy to construct.
If you prefer to build a simple line
filter, figure 7 shows the schematic
diagram of a typical circuit. This cir-
cuit is applicable for use in instances
of minor television interference. It
should clear up most line-coupled
noise problems.
As a practical matter, simple line
filters are less than ideal. Typical
commercial single-section line filters
use toroidal inductors and provide
about 55 dB of attenuation at 3 to 5
MHz. Attenuation can be typically
increased to 70 dB by adding a second
LC (inductance/capacitance) section.
A line filter should be used on the
computer and any susceptible
receivers.
If your TV reception is still garbled
or nonexistent after you install a line
filter, then your set is picking up
radiated noise through the antenna
input. Generally, you will find the
VHF (very-high-frequency) channels
to be affected much more than the
UHF channels. This is because most
of the noise energy generated by the
computer is at frequencies below 100
MHz (VHF channels 2 thru 6 are be-
tween 54 and 88 MHz). At frequencies
above 470 MHz, where channel 14
starts, there isn't much energy in the
noise spectrum.
The process of eliminating
radiated-noise pickup starts with
replacing the 300-ohm twin-lead cable
from the antenna to the television
receiver with 75-ohm coaxial cable. If
the problem persists after you do this,
then additional filtering is in order. If
the noise is determined to be a single
frequency, such as that emitted from
a Citizens' Band radio transmitter
next door, then a parallel-tuned trap
that singles out this one frequency
should be used. Figure 8 shows such a
filter circuit.
Computer-generated noise is
broadband rather than narrow-band.
A parallel-tuned trap cannot be used,
and a different filtering technique
must be employed. A high-pass filter
on the set's antenna input may be
needed. The system clock frequency
of most computers is between 1 MHz
and 8 MHz. Harmonics will, of
course, reach much higher frequen-
cies. The harmonic amplitude
66 January 1981 © BYTE Publications Inc
Circle 38 on inquiry card.
Whatever
happened to
eenie, meenie,
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...a perfect
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i Solomon .
1
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If only
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iracing...
It must use
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.analysis, and..
Brilliant!
Like a window
into the future.
Maybe this'll
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I could
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Should I
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in this economy?
Hp> i
mf Would i ^M
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Winston's millions
H or Billy Joe's a
j^^^^M
^L low-'.' ^^k
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my ticket V
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of these people M
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afford $29.95? J
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H^/i Dec is ion Master speaks everybody listens.
Let's face it. We all have to make decisions. Decisions that can change our lives. Decisions that can
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Use Bayesian theory to peer into the future... even if you've never heard of the Bayes' Rule. A
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professors and top business executives are huili into DecisionMaster's algorithms...
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DecisionMaster is easy to use. It features:
• A fully documented manual developed by an authority in the field.
• A unique program-controlled cross reference system.
• A powerful formatted-screen data entry system.
You'll use DecisionMaster in hundreds of routine decisions,
as well as more important ones such as* Buying a house
• Changing jobs* Selecting investment' Evaluating insur-
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If you buy only one computer program this year,
make it DecisionMaster. And when it speaks.
listen .
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Figure 8: A parallel-tuned trap filter for use on FM-radio or television sets. Each LC
combination is set for resonance at the frequency that is causing the interference. Trap
filters are suitable only for eliminating narrow-band interference such as that from
Citizens' Band radio transmitters.
Here, the cen ter frequency trapped by the filter can be calculated from the equation
fo=159.2/\JLC , where / is the resonant frequency in Hertz, L is the inductance in
microhenrys, and C is the capacitance in microfarads.
300 fl
ANTENNA
O
JT
Ll
<.c>-
-)h-
lOpF
lOpF
1\-
-o"
, 300A
} ANTENNA
TERMINALS
-o
Figure 9a: A high-pass filter for use with 300-ohm antenna cable. A high-pass filter can
be used on television-receiving sets and FM-radio receivers to reduce or eliminate noise
at frequencies under 50 MHz, such as that produced by personal computers. These
filters pass frequencies above 54 MHz (where the VHF-TV broadcast band lies) and at-
tenuate any lower frequencies where noise may reside.
In this design, the inductors Li and L 2 are made from eight turns of 18-gauge wire in a
coil 19 mm (V* inch) in diameter, 25.4 mm (1 inch) long.
diminishes with each successive fre-
quency multiplication.
If we can presume that practically
all of the radiated noise is below 54
MHz where channel 2 starts, then we
can construct a filter that passes only
the frequencies above 54 MHz. The
filter should actually be set for a cut-
off frequency of 45 MHz to reduce at-
tenuation at the desired frequencies
above 54 MHz. In combination with
coaxial cable, the high-pass filter
usually remedies 80% of all in-
terference problems. Figure 9 shows
the schematic diagram of a typical
high-pass filter.
The use of a coaxial cable, a line
filter, and an antenna filter should get
you out of the digital doghouse.
In Conclusion
EMI is but one of the many prob-
lems confronting computer users. I
have only touched on a few of the
basics in this short article, with my
concern obviously centered on the ef-
fect the computer has on other equip-
ment. I hope that I have provided you
with some solutions.
The effect the environment has on
the computer is an entirely different
matter. You have probably noticed
that I have tactfully avoided discuss-
ing things like voltage spikes, line
fluctuations, frequency variations,
and line interruptions. While often in-
cluded in the consideration of EMI,
problems of power-line performance
is an entirely different subject, requir-
ing different solutions.
Noise filtering may improve your
relations with your neighbor, and
reduce the susceptibility of your
equipment to transients, but it will do
nothing to save you from the power
company. It remains for me to cover
this latter problem in a separate
discussion.!
22pF
27pF
27pF
o
75fiJ
ANTENNA)
-)h
^
;39pF
L.5
39pF;
-\—> ANTENNA
I TERMINALS
/ON TV SET
/77
L 6
Figure 9b: A high-pass filter for use with 75-ohm coaxial antenna cable. In this design,
inductors L 3 and L 3 are made from four turns of 14-gauge wire in a coil 6.35 mm (Vt
inch) in diameter and 12. 7 mm {Vi inch) long, tapped one-half turn from the end. Induc-
tors L s and L t are made from ten turns of 22-gauge wire in a coil 6.35 mm (V* inch) in
diameter, with the turns spaced at 3.175 per cm (8 per inch).
Next Month:
Milton-Bradley s Big Trak is a
clever toy. Wireless remote control
makes it even more clever.
Editor's Note: Steve often refers to
previous Circuit Cellar articles as
reference material for the articles he
presents each month. These articles are
available in reprint books from BYTE
Books, 70 Main St, Peterborough NH
03458. Ciarcia's Circuit Cellar covers ar-
ticles appearing in BYTE from September
1977 thru November 1978. Ciarcia's Cir-
cuit Cellar, Volume II presents articles
from December 1978 thru June 1980.
68 January 1981 © BYTE Publications Inc
Circle 204 on Inquiry card.
Two Great New TRS-80 Computers.
Radio Shack- Setting New Standards
For Price and Performance!
K TRS-80 Model III. The new standard in
personal computers— packed with the advanced fea-
tures you want, yet priced unbelievably low! The
Model Ill's handsome one-piece cabinet includes a high
resolution 12-inch monitor that displays 16 lines of 64
upper/lower case characters, and graphics. It also includes
a 65-key typewriter-style keyboard with data pad. There is
room inside for two optional double-density disk drives —
and you can add two more external drives for a total of
approximately 670K bytes of on-line storage. Model III
comes with a two-speed cassette interface, so most of our
huge library of Model I, Level II software can be used. And
the new 1500-baud mode gives you really fast cassette I/O.
The very powerful Model III BASIC language, contained in
14K of ROM, features automatic line numbering, tracing,
PEEK and POKE, machine language programming, key-
board-controlled screen print, I/O device routing, repeating
keys, special characters and lots more. Other Model III fea-
tures include a built-in real time clock, cassette jack and
Model III bus, plus a built-in printer interface for direct con-
nection with Radio Shack printers. With the built-in RS-232
firmware and the optional internal RS-232 board, commu-
nications is a snap! Model III is expandable to 48K RAM at
any time, and is also available with 4K RAM and Level I
BASIC (for only $699*). A full-blown 32K, 2 disk system
with RS-232 is yours for only $2495* This is the break-
through you've been waiting for. Come in and try Model III
today. 16K TRS-80 Model III Only $999*
13-Inch
Color TV Receiver
Available Separately.
Only $399*
16K TRS-80® Color Computer. Vivid 8-color graph-
ics, sound, the high performance 6809E microprocessor
and more — at a very affordable low price! This amazingly
portable new micro attaches in seconds to any TV set. Use
it at work, at school or at home. Its Extended Color BASIC
language provides unique commands for graphics manip-
ulations, easy machine language programming, complex
musical sounds (with more than one note!), PEEK and
POKE, specific error messages and much more. A built-in
RS-232 serial interface lets you attach a modem for com-
munications or a serial printer. Of course, you can save your
programs on cassette (at a fast 1500 baud) — or just pop in
one of our instant-loading ROM Program-Paks for a wide
variety of fast-paced games and valuable personal applica-
tions. Like all TRS-80s, it's easy to expand — add a printer
now, disk drives are on the way. An optional pair of joysticks
brings extra maneuverability and real excitement to com-
puter games. The TRS-80 Color Computer is also available
with 4K RAM and Color BASIC (at just $399*). This is the
multipurpose computer you've been waiting for. Try it today
at your nearest Radio Shack store, Authorized Dealer or
Computer Center. 16K TRS-80 Color Computer with
Extended Color BASIC Only $599*
®
Radio /hack
The biggest name in little computers®
A DIVISION OF TANDY CORPORATION
•Retail prices may vary at Individual stores and dealers. Ask for our FREE 1981 TRS-80 Computer Catalog or Write Dept. 79, 1300 One Tandy Center, Fort Worth. Texas 76102
dFEW
OF THE FEATURES
THdTGVETEMK
THE EDGE 111
PRKE/PERFOOTMIKE
While some of the features of
Terak's new 8600 can be found in
other computer graphic systems,
no other system in the $5K-$20K
price class (and even those costing
thousands more) provides a com-
parable combination of features
and benefits. Features such as
Low Entry Cost The basic
8600 color system is priced at about
$15,000. It can be upgraded to
higher resolution and a greater
number of colors, but even fuJJy
expanded it still comes in at less
than $19,000.
Or, you can start with a black
and white system for less than
$8,500 and upgrade to color at any
time by the addition of a color
processor and monitor.
Simultaneous
Graphic/Text Display
The 8600 offers outstanding
control and formatting of both
graphics and text. Completely
under user control, the multiple
memory planes permit simul-
taneous display and indepen-
dent manipulation of text and
graphics to achieve special
effects such as overlays, scroll-
ing and zoning. This capa-
bility, in conjunction with
Terak's unique flexible charac-
ter generation, enables the
8600 to present visual displays
that are unequalled by any
other system of its class.
Broad Spectrum
of Color Selection
The number of color maps
and the colors in each map is
completely under software
control. With a 6-plane mem-
ory (640 x 480 x 6), up to 64
colors can be displayed on the
screen simultaneously. With
a 3-plane memory (320 x 240 x
3), up to 8 simultaneous colors
can be displayed from any
one of eight color maps. The
output of the color map pro-
duces eight levels each for red,
blue and green. The result
is the selection of 512 possible
levels of intensity, saturation
and hue. Switching from map
to map is under software
control.
The 8600 monitor screen can
be divided into a maximum of
four variable size zones. In <i
typical application, the upper
three zones can display graph-
ics while the lower zone dis-
plays text. The text can be
scrolled or slow scrolled while
the graphics are changing to
coincide with the text changes.
Dual Processors For Speed and
Flexibility The two 16-bit proces-
sors (each with its own memory)
are assigned those tasks which they
can accomplish most efficiently and
with the fastest throughput. The
result is more available user space
in memory faster processing and
increased flexibility of operation.
DEC Based Hardware and
Software The DEC based hard-
ware and software includes the
LSI -11 main processor, RT-11 oper-
ating system and Q bus compati-
bility. As a result the 8600 will
support a variety of software and
easily integrates peripheral devices.
USCD Pascal, Too The 8600
also supports the easy to use USCD
Pascal operating system for pro-
gram development, text editing,
word processing and interactive
applications.
Siggraph Core Standards, 2D1
Level Graphic support is pro-
vided for USCD Pascal and RT-11
for Fortran, Basic and Pascal.
The Other Reasons? Add such
things as graphics display list
processing, a high resolution quad-
rant, four modes of display blank-
ing, emulation, remote on-line
diagnostics, etc. The list goes on
and on. But to fully appreciate
the system you should see one in
action. We'll be happy to set up
an appointment. Just contact us.
CORPORATION
14151 North 76th Street
Scottsdale, Arizona 85260
(602) 998-4800
Circle 39 on Inquiry card.
u
I
f!
ible
Character Generation
nlike the rigid cell sizes of
many graphic display systems,
the 8600 character generation
is under software control.
Characters can be programmed
to any size or shape including
the creation and display of
oreign languages such as
Arabic, Hebrew, Russian, etc.,
mathematical symbols, primi-
tives, specially configured
letters, characters or symbols
and a host of others.
Fill Algorithms
Terak's fill algorithms are fast
and allows you to fill the inside
of simple or complex geometric
figures without calculating points.
This not only helps define charts,
graphs, etc., but greatly enhances
the appearance of presentation
material.
DYNAMIC
FEATURES
The 8600 also offers several
dynamic features that are
impossible to illustrate and
must be seen to fully appreciate.
Smooth or Line Scrolling
The speed of the vertical,
bi-directional scrolling is under
operator control. It can be
slowed down for text editing
or speeded up for search. And,
unlike most terminals that
jump a line at a time, the 8600
moves in increments of one
scan line. The result is a smooth
moving text that is easy to read.
External Video Synch
The 8600 can be synchronized
to receive externally generated
RGB signals or transmit 8600
signals to external video moni-
tors. This lets you combine
and/or overlay internally and
externally generated characters
and graphics onto a single
screen if mixing hardware is
incorporated in the system.
■ ■ , ■
The NEC PC-8001: A New
Japanese Personal Computer
Michael Keith
D46 Abbington Dr
Hightstown NJ 08520
C P Kocher
505 South 42nd St
Philadelphia PA 19104
One of the products attracting a lot
of attention at the 1980 NCC (Na-
tional Computer Conference) in Ana-
heim, California was the PC-8001
personal computer produced by NEC
(Nippon Electric Company). Because
this well-made little machine has been
selling briskly in Japan, NEC was try-
ing to gauge consumer reactions to
the PC-8001 that would aid them in
deciding whether or not to sell it in
the US.
This article is based on our evalua-
tion of a PC-8001 that some col-
leagues purchased in Japan. When we
first received it, we were bewildered
because all the instructions and docu-
mentation were in Japanese (with
only the BASIC commands in
English). After several months of
poking, playing, and progamming,
some syllabie-by-syllable translitera-
tions of the katakana (a Japanese
syllabary) instruction manual, and a
few puzzled visits to Hiro, a Japanese-
American co-worker, we believe that
we have a good understanding of the
PC-8001's most important features,
its strong points, and its limitations.
Photo 1 shows the basic com-
ponents of the computer. It consists
of two units: a keyboard (including
both the processor and memory) and
The processor Is an
NEC version of the Z80
running at 4 MHz.
a color monitor, and it features a 24
K-byte version of Microsoft BASIC in
ROM (read-only memory). The dol-
lar equivalent prices of the keyboard
unit and monitor are $700 and $910,
respectively. [These prices, however,
may be only distantly related to the
final price of the American version of
this microcomputer. . . . G VV/
Keyboard
The eighty-two-key keyboard has a
high-quality standard English alpha-
bet keyboard, five user-definable
function keys, and a separate numeric
keypad. In the normal mode, the user
can enter uppercase and lowercase
Roman characters; if he presses a
locking shift key, he can enter char-
acters in the Japanese katakana sylla-
bary as well. Pressing a letter key and
the nonlocking "graph" key causes
one of a set of graphic characters to
be displayed; this set includes bars,
arcs, crosses, hearts, spades, clubs,
and diamonds. (Although the kata-
kana character set may appear useless
to most American users, the char-
acters are visually interesting and
nicely augment the set of graphics
characters.) All the characters avail-
able are shown in photo 2. There is
also a reset button on the back of the
console, so it can't be hit accidentally.
Inside the keyboard unit, the most
noticeable feature is the switching
power supply, which is mounted in a
long, thin metal cage (approximately
38 by 6.35 by 3.175 cm [15 by 2Vi by
IV* inches]) extending along the en-
tire rear of the keyboard enclosure.
(See photo 3.) The elongated shape
allows the entire power supply to be
suspended over the printed-circuit
board under the only portion of the
cabinet that can be vented. During
operation, however, the power
supply remains cool.
The 22.9 by 38.1 cm (9 by 15 inch)
printed-circuit board has three
layers, but the center layer does not
appear to be nearly as extensive as the
other two layers. There are at least
sixteen test-point posts staked into
the board.
Most of the integrated circuits are
mounted directly on the board, but
the circuits that are either expensive
or might have to be replaced (the
72 January 1981 © BYTE Publications Inc
memory, central processor, DMA
[direct-memory access] controller,
USART [universal synchronous/
asynchronous receiver-transmitter],
video display device, and font mem-
ory) are all in sockets. The board is
easy to remove because all connec-
tions to it — power, keyboard, beep-
er — are made with plugs and sockets;
there are no external connections or
even jumpers soldered to the board.
The processor is an NEC version of
the Z80 running at 4 MHz. The
BASIC ROM occupies the 24 K bytes
of memory from hexadecimal 0000 to
5FFF, and hexadecimal locations 6000
to 7FFF are available for an expansion
ROM. Standard programmable mem-
ory extends from hexadecimal loca-
tions C000 to FFFF, with locations
8000 to BFFFF available for expan-
sion. The board has empty sockets
available for both expansion ROM
and programmable memory. A time-
of-day clock is included on the board
(see figure 1).
The video controller is a custom
NEC integrated circuit. There are two
separate video output connectors on
the back of the keyboard unit. A
5-pin DIN (Deutsche Industrie Norm)
connector provides a baseband video
signal for a black and white monitor
and a similar 8-pin connector pro-
vides red-green-blue signals for a col-
or monitor. With a black and white
display, colors appear as different
shades of gray.
In addition to a video-out signal
and ground, the 5-pin connector pro-
vides V DD ( + 12 V) and horizontal
and vertical sync signals. The 8-pin
connector provides V DD , ground,
color-clock signal, horizontal and
vertical sync signals, and red, green,
and blue signals. Although the color
monitor has an audio amplifier and
speaker, the processor does not use
them. The only sound made by the
PC-8001 is provided by a 2-inch
speaker mounted on the power sup-
ply. The user can only control the
duty cycle of a fixed-frequency
beeper.
Another DIN connector and an
adapter cable provide an interface to
any standard cassette recorder for
program loading and storage. The en-
coding scheme is 600 bps (bits per sec-
ond) FSK (frequency shift keyed)
Kansas City format (which uses 1200
and 2400 Hz frequencies). This en-
coding scheme is very robust — unlike
many computers, almost any volume
setting on the tape recorder is okay.
A relay inside the console controls the
tape recorder motor (or any other
motor for that matter— a MOTOR
command in BASIC allows a user to
toggle this relay).
A 16-pin socket on the printed-
circuit board serves as an RS-232C
connector, while cutouts at the back
of the cabinet give access to a pair of
edge connectors on the board. One is
for a printer and one is a DMA chan-
nel. An expansion unit is available to
interface the DMA channel to up to
four disk drives, two RS-232C serial
Photo 1: The NEC PC-8001 personal computer system. Shown here is the basic system:
high-resolution color monitor, keyboard unit, and documentation (reference manual,
BASIC manual, and BASIC reference card).
* in see
Wiln U37','*H)97' ' = m AY**HiOWWHttArt: ?'4? iUmim IQT/ ' - m AT4WtO\
HttVtA iWSWWiV * WW,
pfl
p STUWXVZ[»^abcdefghi^iiirayqr5tuw
^7Uyfhl37VHD9y ,, =WAVW*0\XrTlfl»aA , it?'4?^y^l37 l J»l'D97 ,, r^AV«»MW\
wyuu .
■
^7;^1'l37'Jll^/'=WAVm4t0NJl<r»W?A^7^t?Uy^l37y»l'DTy , rWAV«»««\
RSTUVHXYZ[« A _
. abcdefghiJklmnopqrstuw.u^ORSTUVHXYZm*. abcdefghiJklrmiwstuti
IIIIW3tO--I Ir.Un-' * aJHttir M ' ' In"*-'
Photo 2: A display illustrating the colors and the character set on the PC-8001. In addi-
tion to complete ASCII, there are various graphics characters, control characters, and
katakana characters.
January 1981 © BYTE Publications Inc 73
Terminals
super price. Dol matrix, serial parallel
& current loop standard. 180 c.p.s. Bi-Directional
Memory Integrated Circuits - Call for Qty. discounts
when ordering over 50 units.
Motorola 4116 (200 Nanosecond, Plastic) $4.50 EA.
Fairchild 21 14 (Standard Power, Plastic) $4.50 EA.
CompuMart
i you put'em
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NEW from
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IT is the new Intermediate
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NEW From Integral Data
The IDS 445 Printer
So new all we can tell you is that it's fantastic. Priced
lower than the 440 and equipped with a better print
head. Advanced technology strikes!
IDS 445 w/Graphics Capabilities $894
IDS 445 w/o Graphics Capabilities $795
The IDS 460
Since its introduction 5 months ago this
printer has already proved itself. Features
include: Correspon dence quality printing,
High-resolution graphics
capability,
programmable
print justification
—a great printer,
$1,295
CENTRONICS ^-^'
PRINTERS
New! The incredible Model 737- Correspondence
and Draft Quality Printing for Under $1,000. This is
the first printer in its class to offer print quality
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737-1 (Parallel Interface)— $899
737-3 (Serial Interface) $1,045
Tractor Feed Printer- Centronics' Most Popular
Model. Perfect for the needs of a small business
sytesm. Recommended by Apple and Radio Shack.
$1,079
FREE Cable with purchase of any Centronics printer.
The Omni 810 Printer from
Texas Instruments
Tl Omni 820 Receive-Only (RO) Package. Includes
machine-mounted paper tray and cable. A com-
pressed print option and device forms control are
standard features. $2,155
Tl Omni 820 Keyboard Send Receive (KSR) Package
comes with full ASCII keyboard with numeric key-pad
and an EIA cable with autospeed select. $2,395
with
10 day
free return
CompuMart has been selling computers by
mail since 1971 . Our thousands of satisfied
customers rely on CompuMart for services
not generally available from the others.
Namely:
• Product Selection/Each product advertised
by CompuMart has been evaluated by our in-
house staff for best price, performance, and
supplier reliability.
• Return Privilege/After receipt of our prod-
ucts, you are protected by CompuMart's
exclusive, 10-day return priviledge good for all
products except software.
• Support/Our Customer Service Dept. and
expert technicians are always there to assist
you by phone or at CompuMart's outlets. Our
knowledgeable phone sales force can provide
you with detailed information and complete
product specifications.
• Phone Ordering/For added convenience,
CompuMart maintains a toll-free ordering
number. 1-800-343-5504.
• Phones open M T W Th F 8:30 a.m. - 7:00
p.m. Sat. 11:00 a.m.- 4:00 p.m.
Compumart will throw in
a FREE fabric ribbon and
Currier 72 element when
you buy a NEC from us.
We've got the following Lear
Siegler Terminals In Stock at prices
too low to print— Call for quotes.
ADM-3A Industries favorite dumb terminal tor
some very smart reasons.
ADM-3A.+ New from Lear Siegler. CALL!
ADM-31. The terminal that's too smart to
be considered dumb.
ADM-42. Available with keyboard or without,
semi intelligent terminal offering tremendous
user flexibility. The optional configurations
are amazing. Ca( | f Q| . details.
Limited Time Offer
We've slashed our Hazeltine prices
again!
Hazeltine 1410 List $850 CompuMart $749
Hazeltine 1420 List $995 CompuMart $825
Hazeltine 1500 List $1095 CompuMart $965
Hazeltine 1510 List $1395 CompuMart $1135
Hazeltine 1520 List $1585 CompuMart $1199
Hazeltine 1552 List $1395 CompuMart $1235
Calculators
HEWLETT-PACKARD'S HP-41C
HP-41C Calculator $288.00
The System
Memory Modules. For storing programs or up to
2,000 lines of program memory $45.00
"Extra Smart" Card Reader. Records programs
and data back onto blank mag-cards $199.00
The Printer. Upper and Lower case, High
resolution plotting, Portable Thermal operation
$355.00
Application Modules $45.00 EACH
Texas Instruments TI-99/4
Home Computer
Save $300 on this 16-Bit computer with
monitor
TI-99/4 w/o Monitor
$659
NOVATION CAT™
ACCOUSTIC MODEM
• Answer Originate • Bell 108
• 300 Baud . Low Profile Design
Looks good, works great! $179.00
NEW! D-CAT
Direct Coupler from NOVATION $199.
Monitors
EXCLUSIVE from CompuMart!
Special Offer. Zenith Color Video
Monitor for $379!
NEW FROM SANYO — Four Great Moni
tors at Low CompuMart Prices.
Sanyo's new line of CRT data display monitors are
specifically designed for the display of alpha-
numeric or graphic data.
9" Sanyo Monitor $169
12" Sanyo Monitor $289
12" Sanyo Monitor with green screen
$299
13" Sanyo Color Display Monitor
$495
Computers
[apple
We carry the most complete inventory
of Apple computers, peripherals, and
software. CALL!
Our Best Selling Apple System:
Save over $250 on our most popular
Apple System. System! includesa 48K
Apple II. Apple Disk & Controller, and
a Sup R Mod RF Modulator.
List: $2,020
Compumar! Sale Price: $1,769
New from Apple tor the Apple II:
DOS 3-3 Convert disks to 16 sector format for 23%
more storage and faster access S60
Apple Plot. The perfect graphic complement for
Visicalc. $70
Dow Jones News & Quotes $95
Adventure (Uses 48K) $35
DOS Tool Kit $75
Apple Fortran $200
Silentype Printer w/Xface $595
Visicalc $149
Tax Planner $120
From Symtech & Info Unlimited
Supersound Generator (mono) $159 (stereo) $259
Light Pen $249
X-10 Controller (plugs into paddle port) $49
From Personal Software
Visicalc $149
Desk top plan $99
New from Videx! — Video Term
80 Col. x 24 line
7x9 matrix, plug in compatible board for the Apple
II. Price $325 without graphics EPROM. With
graphics EPROM $350.
New from MUSE
The Voice $39.95
Super Text $99.00
Address Book $49.95
Mountain Hardware — Expansion accessories for
your Apple
lntrol/X-10 System $289
Super Talker $299
The Music System $545
ROM plus board w/keyboard filter $199
Clock Calendar S280
16 Channel A to D Converter $350
Apple Expansion Chassis $650
ROM Writer $175
Miscellaneous Apple II Accessories:
Easy Writer (80 col. need Videx) $249
Easy Mover $ 49
Easy Mailer $ 69
Dysan Diskettes ea. $ 5
S.S.M. Serial & Parallel Apple Interface $225
ABT's Numeric Key Pad $110
COMMODORE
Buy direct from the biggest — Compumart has deliv-
ered more Commodore computers in the U.S. than
any other dealer. We were Commodore's first dealer
and carry everything Commodore manufactures. In
stock for immediate delivery! Call us now for low
prices and special deals.
NEW FOR PET:
Visicalc (Need 32K and a disk drive) $199
Word Pro 1, 529.95 • Word Pro 2. $99.95 •
Word Pro 3. $199.95 • Word Pro 4, $299.95 •
The Amazing
HP 85
Hewlett-Packard's Personal Computer for Industry.
This extremely portable computer features ex-
tended BASIC lo solve your problems quickly and
efficiently along with an advanced graphics sys-
tem to enhance communication.
We carry H.P. Peripherals (Disk Drives to Graphics
Plotters) Enhancements: (BASIC Training, General
Statistics, Financial Decision, Math, Linear Program-
ming $95 ea.); HP-85 Accessories: (Enhancement
ROMs, ROM drawer, Overhead Transparency Kit);
Supplies: (Plotter Pens, Tape Cartridges); Interface
Modules (HP-IB Interface, HP-IB Interconnect
Cables. Serial (RS-232C)
Interface Module).
We can get your every
HP peripheral made for the
HP-85. CALL FOR
COMPLETE DETAILS
& SPECS.
3 Ways to save when you buy
the Atari 800 from us. Choose from
one of the following offers.
ATARI
1 ) Free 8K of memory with purchase.
(So your Atari will come to you with 24K.)
2) Free 410 program recorder with purchase ($89.95
value).
3) $100 off Atari Disk Drive purchase.
ATARI 800 Personal Computer
System —
Comes with 800 Operators Manual, 16K RAM
Memory module, 10 K ROM Operating System,
power supply, TV Switch Box. $950.
PERIPHERALS
Atari 410 Program Recorder (FREE w/purchase of
Atari 800) $ 89.95
Atari 810 Disk Drive ($100 off with purchase) 699.95
New Dual Disk double density 1499.95
825 Printer (Centronics 737) 995.00
RS232 Interface w/Cable 249.95
NEW! Light Pens 74.95
New! Visicale for Atari $199.
EXIDY SUPER SALE!
We want to clean out our inventory of Exidy com-
puters and peripherals. To do this we've priced our
Exidy equipment so low you'll have to call us for
prices.
ROCKWELL AIM 65
The single board development system
that's perfect in the classroom or lab.
Our AIM System includes: 4K AIM with BASIC
interpretor assembler, Power Supply, Cassette
recorder & Enclosure $799.
4K AIM — 65
PL65 High Level Language
Paper for the AIM (roll)
Rockwell's 4-slot Motherboard (SALE)
$499
$125
$ 2.50
$175
CompuMart's Microflex 65 System for your AIM
Includes: Adapter Buffer Module w/ 4-slot module
stack, 8K RAM module, 16K PROM/ROM module,
Asynchronous communications Interface, & Power
Supply $1,299
Call or write for
our complete
Microflex 65
brochure
Piggy-back
for the AIM
NEW! The PMC-80
The new 12K computer
that's SOFTWARE
COMPATIBLE with
the TRS-80.*
Level II 16K at $645
Just think, now you can choose from the thousands
of software packages already developed for the TRS-
80 and run them on a computer costing only $645.
But the PMC-80 is more than just a computer that
accepts TRS-80 software. Its features include: Reads
all Level II BASIC tapes. Reads all SYSTEM tapes.
Full range of peripherals. Video output for monitor
and TV. Optional FASTLOAD at 8000 baud. Optional
Upper/Lower case. Call for complete specs.
"TRS-80 is a registered trademark of
Tandy Radio Shack
Phones
open from
8:30 a.m. to
7:00 p.m., Mon.-
Fri.; 11:00 a.m. - 4:00
p.m. Sat. P.O.'s accepted
from Dun & Bradstreet
rated companies - shipment
contingent upon receipt of signed
purchase order. Sale prices valid for
month of magazine date only - all prices
subject to change without notice. Our Ann
Arbor retail store is open 11:00 a.m. to 7:00
p.m. Tues.-Fri., 10:00 a.m. to 5:00 p.m. Saturdays.
Stop by and visit.
^^\J§}tli^^Ji}/ir\a\ I Circle 40 on inquiry card
270 THIRD ST., DEPT. 113, P.O. BOX 568, CAMBRIDGE, MA. 02139 x
Member Computer Dealers Assoc.
We've had a reputation for dependability since 1971
Photo 3: Inside the keyboard unit. The bottom of this photo corresponds to the front of
the keyboard. Along the top edge is the power supply and, below it, the main printed-
circuit board. The reset button can be seen at the rear of the keyboard near the power
cord.
We don't play hard to get
gpaaoa etsgDcaags 1[@^mb ]
MQGas
SE)GD(3^fi?O0[a I
Fast, reliable delivery
of personal computer
software programs.
If you have an Apple or TRS-80
computer, Minnesota Software Inc. has
hundreds of programs — in stock and
available right now by mail order.
Choose from entertainment, learning or home-application programs. All software
is immediately available and features a money back guarantee.
TO GET A COPY OF OUR NEW CATALOG, CONTACT JOHN WEST.
PHONE 612/426-0916. SOURCE- TCH122. MICRONET - 70040,555. OR DROP
US A NOTE.
MINNESOTA SOFTWARE, INC.
5422 Fisher St. White Bear Lake, MN 55110
Apple is a registered trademark of Apple Computers. TRS-80 is a registered trademark of Radio Shack. A Tandy Corp.
IM-BASIC, written by
Microsoft, is a floating-
point BASIC capable of
operating in either
single or double
precision.
ports, a parallel port, and an IEEE
(Institute of Electrical and Electronics
Engineers)-488 bus (see figure 2).
Monitor
Everyone who has seen the NEC
color monitor has commented favor-
ably on its convergence and overall
quality of construction. The CRT
(cathode-ray tube) is a 30.48 cm (12-
inch) diagonal tube and has an in-line
gun structure and dot screen face with
12-mil (0.012-inch) dot spacing. The
deflection yoke is the precision
wound torodial type. Convergence is
excellent: during construction,
wedges were inserted between the
yoke and the neck of the tube to shim
the yoke into correct alignment.
The chassis is transformer power-
ed. Almost all the electronics are
mounted on one large single-sided
printed-circuit board. The horizontal
scan frequency is 15,974.4 Hz, and
the vertical scan frequency is 60 Hz.
The monitor uses an RGB (red-
green-blue) signal interface with
separate horizontal and vertical sync
signals. All signals are at TTL
(transistor-transistor logic) levels.
Although the monitor has an audio
amplifier and speaker, the audio line
on the connector is tied to V DD on the
Z80 microprocessor. The computer
generates a format of up to 80 char-
acters per line and 25 lines, noninter-
laced. The image quality is excellent,
as can be seen from photo 2.
The monitor power supply ap-
parently has some sort of time delay
element, either intentionally or unin-
tentionally, that prevents the user
from turning on a set that is still
warm. If you turn the monitor off
and then try to turn it back on again
without waiting a minute or so, the
screen remains dark.
Software
As mentioned previously, the
BASIC by Microsoft, called N-
BASIC, is contained in three 8 K-byte
ROMs. Contained within these 24 K
76 January 1981 © BYTE Publications Inc
Circle 41 on inquiry card.
Circle 42 on inquiry card.
SYBEX SPEAKS YOUR LANGUAGE . . .
THE PASCAL HANDBOOK by Jacques Tiberghien
— A dictionary of every Pascal instruction, function,
operator and reserved word covering virtually all
versions of Pascal. 300 pp., 150 III., Ret. P320, 7"x9",
$14.95 ■
INTRODUCTION TO PASCAL (Including UCSD
PASCAL) by Rodnay Zaks — A step-by-step introduc-
tion for anyone wanting to learn the language of
PASCAL. Describes UCSD and Standard Pascals. 440
pp., KK) III., Ref. P310, 7"x9", $12.95 ■
INSIDE BASIC GAMES by Richard Mateosian -
Uses a games format to teach program design in
BASIC. Games run on TRS-80, APPLE II, PET/CBM
and others. 300 pp., 1 00 III., Ret. H245, 7"x9", $13.95 ■
FIFTY BASIC EXERCISES by |.P. Lamoitier
Teaches BASIC by actual practice using graduated
exercises drawn from everyday applications. All ex-
ercises written in Microsoft BASIC. J00 pp.. 140 III.,
Ret. B250, 7"x9", $12.95 ■
THE CP/M HANDBOOK by Rodnay Zaks - Com-
plete instructions and reference handbook for CP/M
— the industry standard in microcomputer operating
systems. 336 pp., 100 III., Ref. C300, 5W'x6W, $13.95 ■
PROGRAMMING THE Z80 by Rodnay Zaks - A
complete course in programming the Z80
microprocessor and a thorough introduction to
machine language. 620 pp., 200 III., Ref. C280,
5'//'x8'/..", 2nd Ed. $14.95 ■
PROGRAMMING THE 6502 by Rodnay Zaks -
Machine language programming of the 6502 from
basic concepts to advanced data structures. 392 pp
160 III., Ref. C202, 5W"x8'//', 3rd Ed., $12.95 I
6502 APPLICATIONS BOOK by Rodnay Zaks -
Real life application techniques: the Input/Output
book for the 6502. 288 pp., 207 III., Ref. D302,
5'//'x8'//', $12.95 ■
6502 GAMES by Rodnay Zaks — Third in the 6502
series. Teaches advanced programming techniques
using games as a framework for learning. (04 pp., 140
III., Ref. G402, 5l4"x8lV', $12.95 ■
YOUR FIRST COMPUTER by Rodnay Zaks - The
most popular introduction to small computers, what
they do and how to buy one. 280 pp., ISO III,, Ref.
C200A, 5'/j"x8'/i", 2nd Ed., $7.95 ■
MICROPROCESSORS: FROM CHIPS TO SYSTEMS
by Rodnay Zaks — Covers components, concepts
and techniques from basic to advanced. 420 pp., 257
III., Ref.C201,5 l /i"x8Vi", 3rd Ed., $10.95 ■
MICROPROCESSOR INTERFACING TECHNIQUES
by Austin Lesea, Rodnay Zaks — Hardware and soft-
ware interconnect techniques including D to A con-
version, peripherals standard buses and
troubleshooting. 464 pp., 400 III., Ref. C207, 5Vi"\»Vi",
3rd Ed., $15.95 ■
PROGRAMMING THE Z8000 by Richard Mateosian
— Architecture and function of the Z8000 and its
family of support chips. Includes programming in
Z8000 machine language. 312 pp., 124 III., Ref. C281,
5'/j"x8'/j", $15.95 ■
tfsVBE
MAIL TO: SYBEX
DEPT. B1 % _
2344 SIXTH STREET ^^^T
BERKELEY, CA 94710
Phone Orders: 415/848-8233
NAME
ADDRESS.
CITY
D SEND ME YOUR FREE CATALOG
STATE
ZIP
ADD D $1 .50/book UPS or D 75</book 4th class mail (CA add tax)
OR CHARGE MY D VISA □ MC □ AM EX. CARD NO
Total Amt. Enclosed.
SIGNATURE
EXP. DATE.
bytes of ROM is a very complete
BASIC, as well as a system monitor
program. Advertisements in the
Japanese computer magazine ASCII
indicate that a number of user pro-
grams (including a color version of
the ever-popular Space Invaders) are
readily available on tape.
N-BASIC is a floating-point BASIC
capable of operating in either single
or double precision. All the features
of standard BASIC are present, along
with a few interesting extensions,
such as:
• SWAP: exchanges value of two
variables;
The PC-8001 has one
feature that ought to
be Included In all per-
sonal computers: a
single BASIC command
that changes It from a
computer to a terminal.
• BEEP, MOTOR: toggles beeper or
motor relay;
• HEX$: decimal to hexadecimal con-
version;
• STRINGS (X,Y): string equal to X
copies of the character with ASCII
(American Standard Code for Infor-
mation Interchange) code Y.
In addition, there is a whole set of
graphics and display commands that
will be described further.
There is also a monitor program
which gives the user direct access to
the Z80 machine code. After entering
the monitor by typing MON, the user
can test, manipulate, load or store
bytes of blocks of memory using the
commands in table 1.
Another useful feature of N-BASIC
is the use of the ESC (escape) key on
the keyboard as a pause function. It
PC - 8001
r
CPU
780-1
RAM
/iPD4161-3
c
ROM
^PD2364
TIMER
/1PD1990
CASSETTE
INTERFACE
SPEAKER
P
RS232C
PRINTER
INTERFACE
MODEM,
ETC.
SERIAL
I/O
INTERFACE
SYSTEM BUS
KEYBOARD
L^
DMAC
/iPD
8257
DISK
DRIVES
»
h_rl Hs~\
DISK
DRIVES
I
DISK
INTERFACE
OR
CRTC
fiPD
2301
CHARACTER
GENERATOR
HORIZ.
AND
VERTICAL
TIMING
INTERFACE
RGB
COLOR
MONITOR
EXPANSION
UNIT
■IEEE488
-RS232C
-PARALLEL I/O
±1
RF MOD-
ULATOR
BSW
TV
tl
E3 S3
DISK
DRIVES
— »>
DISK
DRIVES
Figure 1: Block diagram of the NEC PC-8001 system. The modules within the dotted lines are contained in the PC-8001 keyboard
unit.
POST-HASTE MAILING LIST
Software written in UCSD Pascal *
• 3 lines of address
• Ability to handle foreign addresses
• Address lines 35 characters long
• List on 80 or 132 character printer
• Print 1, 2, 3 or 4-up labels
• Access records by full or partial name
• Update files with screen-oriented input
• 50 character user definable field
• Select records using complex select criteria
• Sort selected records on up to 6 fields
These are some features of our professional mailing list package, the Post-Haste Mailing List. It is designed to
meet the demand of users of both large and small mailing lists. The mailing list file is indexed by a B+ tree
for fast record retrieval and may contain in excess of 40,000 records if the disk space is available.
Post-Haste Mailing List $100. Also available, PFAS, key file access for CJCSD Pascal from $100.
C.J. WIGGLESWORTH SOFTWARE, P.O. Box 755, Cardiff-by-the-Sea, CA 92007
"UCSD Pascal is a Trademark of the Regents of the University of California.
Circle 43 on Inquiry card.
78 January 1981 © BYTE Publications Inc
Circle 44 on Inquiry card.
Multi-User
UniFLEX is the first full capability multi-user
operating system available for microprocessors.
Designed for the 6809 and 68000, it offers its
users a very friendly computing environment.
After a user 'logs-in' with his user name and
password, any of the system programs may be
run at will. One user may run the text editor
while another runs BASIC and still another runs
the C compiler. Each user operates in his own
system environment, unaware of other user
activity. The total number of users is only
restricted by the resources and efficiency of the
hardware in use.
I
Support
The design of UniFLEX, with its hierarchical file
system and device independent I/O, allows the
creation of a variety of complex support
programs. There is currently a wide variety of
software available and under development.
Included in this list is a Text Processing System
for word processing functions, BASIC interpreter
and precompiler for general programming and
educational use, native C and Pascal
compilers for more advanced programming,
sort/merge for business applications, and a
variety of debug packages. The standard
system includes a text editor, assembler, and
about forty utility programs. UniFLEX for 6809 is
sold with a single CPU license and one years
maintenance for $450.00. Additional yearly
maintenance is available for $100.00. OEM
licenses are also available.
FLEX
Multi-Tasking
UniFLEX is a true multi-tasking operating system.
Not only may several users run different
programs, but one user may run several
programs at a time. For example, a
compilation of one file could be initiated while
simultaneously making changes to another file
using the text editor. New tasks are generated
in the system by the 'fork' operation. Tasks may
be run in the background or 'locked' in main
memory to assist critical response times. Inter-
task communication is also supported through
the 'pipe' mechanism.
UniFLEX is offered for the advanced
microprocessor systems. FLEX, the industry
standard for 6800 and 6809 systems, is offered
for smaller, single user systems. A full line of FLEX
support software and OEM licenses are also
available.
chnical /y/tenrv
LfflrS jltantr, inc.
Box 2570, West Lafayette, IN 47906
(317)463-2502 Telex 276143
'"UniFLEX and FLEX are trademarks of Technical
Systems Consultants, Inc.
Circle 45 on inquiry card.
MBC Systems, Inc.
(203) 342-2747
NORTH STAR HORIZON:
HRZ-2-32K-D-Factory ASM$2275
HRZ-2-32K-Q-Factory ASM$2675
64K DD or Q Also Available
HDS-18-F $4449
Northword DQ $ 295
INFO-Manager $ 365
Mail Manager $ 235
General Leger $ 775
ACC. REC. OR ACC. PAY . . $ 445
Word Star $ 350
Medical-Dental SYS $2500
COMMODORE
2001-32K-BorN Keyboard $1090
8K and 16K Also In Stock!!!!
8032 (80 Column Screen) $1599
2040 Dual Floppy Drive $1090
8'050 Dual Floppy (1MEG)$1599
2022 Tractor Printer... $ 749
Word PRO IV $ 290
VISICALC $ 195
APPLE II PLUS Call For Price!
ATARI 800 $ 849
TI 99/4 Console&Monitor . . $1190
INTERTEC SUPERBRAIN:
32K RAM $2595
64K RAM $2795
PRINTERS
Letter Quality:
NEC 5510 or 5530 $2550
NEC 5520 KSR $2950
DIABLO 630 $2390
C.ITOH $1690
Dot Matrix:
CENTRONICS 730 $ 629
" " 737-1 $ 849
" " 799 $999
EPSON MX-80 $ 599
PAPER TIGER 460G $1250
BASE II MST $ 64 9
DISPLAY TERMINALS
HAZELTINE 1420 $ 949
" " 1500 $ 999
INTERTUBE III $ 775
TELEVIDEO 920C $ 849
Since 1977 complete sales and
service. Most items in stock,
prices are subject to change.
Visa and Master Charge welcome
Most items shipped by UPS.
MBC Systems, Inc.
28 MARLBOROUGH STREET
PORTLAND, CONN. 06480
(203)342-2747 TWX 710-428-6345
M-F 9-6 SAT. 9:30-3:00
can be used to pause in the middle of
a program execution, program
listing, monitor dump, and just about
any other process. Pressing ESC
again resumes the program or listing.
This is very handy for debugging or
for reading parts of a long program
listing.
Finally, the PC-8001 has one
feature that ought to be included in
all personal computers: a single
BASIC command that changes it
from a computer to a terminal. The
TERM command allows the user to
select either ASCII or JIS (Japanese
Industry Standard) coding, parity,
and clocking options. A jumper in-
side the keyboard unit selects data
-
Command Meaning
S xxxx displays the byte whose address is xxxx and changes it to the value to be
entered
D xxxx, yyyy displays the hexadecimal values stored in locations xxxx to yyyy
G xxxx goes to byte xxxx and starts executing
W xxxx, yyyy writes to tape the block from xxxx to yyyy
L loads a stored block from tape back to memory
LV loads a stored block from tape and verifies that it has been correctly
loaded
TM tests memory and returns to BASIC
control-B returns to BASIC
Table 1: Monitor commands within the NEC PC-8001. These commands
available to the user for work in machine-language programming.
are
CONSOLE <T>, <N>, <K>, <M>
Sets the following display parameters:
T =top line of scrolling window
N = number of lines in scrolling window
K =key list flag; if 1, displays identity of programmable function keys
M = color mode: 1 = color, = black and white
COLOR <C>, <B>, <M>
Sets the following parameters:
C = color (or attribute in black and white mode):
In Color Mode:
= black
1=blue
2 = red
3 = magenta
4 = green
5 = cyan
6 = yellow
7 = white
In Black and White Mode:
Bit = visibility (0 = visible)
Bit 1 = flashing (1 = flash)
Bit 2 = reverse video (1 = reverse)
For example, color 6 in black and white mode would pro-
duce flashing, reverse-video characters.
B = background character; fills the background with the character whose ASCII code is
B.
M = mode flag, 1 = graphics mode, = text mode
WIDTH <H>,<V>
sets screen format (H by V); (H = 80, 72, 40, or 36; V = 25 or 20)
LOCATE <X>, <Y>
moves cursor to character position (X,Y)
PSET(<X>, <Y>, <C>)
draws a graphics dot at graphics coordinate X,Y in color C
PRESET (<X>, <Y>)
erases a graphics dot at X,Y
LINE(<X1>, <Y1>)-«X2>, <Y2>), "<char>", <C>,[B[F]]
Draws a line from (X1.Y1) to (X2,Y2). The line is a line of text characters "char". If
"char" = PSET or PRESET, the line is a graphics line and X and Y are interpreted as
graphics coordinates. <C> is the color of the line. If present, B causes a rectangle
(block) to be drawn with (X1.Y1) and (X2.Y2) as opposite corners, and F causes the
rectangle to be filled.
GET @ (<X1>, <Y1>)-(<X2>, <Y2>), X
stores characters from the specified rectangular area of the screen into array X
PUT @ (<X1>, <Y17>)-(<X2>, <Y2>), X
puts characters from array X to the display
Table 2: Commands for color-graphics display from within N-BASIC.
80 January 1981 © BYTE Publications Inc
Circle 46 on Inquiry card.
ew muscle
for Heathk it
Now with new CPIM Systems Software
for thousands more programs... and new
8-inch disk system for millions more bytes.
The Heathkit All-ln-One Computer now has space
for 64K of addressable RAM, so you can run bigger,
more complex programs.
And our new CP/M'-' Operating System (Standard
ORG-0, Version 2.2) makes thousands of CP/M pro-
grams available to you. Heathkit systems can run
more, do more, store more than ever before.
A new 8-inch double-sided, double-density disk sys-
tem, with over 1 million bytes per drive, is now avail-
able for Heathkit H-89 and H-8 Computers.
The new 8-inch disk system features soft-sectored
disks for IBM"" compatibility. It's capable of operat-
ing in standard IBM 3740 format. And the 8-inch sys-
VISIT YOUR HEATHKIT STORE
Heathkit products are displayed, , — -
sold and serviced at Heathkit
Electronic Centers*, located in
major cities throughout the U.S. '
and Canada. See your white
pages for the store nearest you.
'Units of Veritochnology Electronics
Corporation, in tho U.S.
tern can be used in conjunction with 5 1 /<i-inch
systems. For compatibility with the rest of the in-
dustry, Heathkit Computers may just be the most
flexible systems you can buy.
All Heathkit computers and peripherals are avail-
able in money-saving, easy-to-build kit form — or
completely assembled and factory tested. All are
supported by the best documentation in the busi-
ness and by 62 service centers throughout the U.S.
and Canada. You're never out in the cold.
For complete details and prices on Heathkit com-
puters, peripherals and software, write today for
the latest Heathkit Catalog or visit your
-rx eFfflM nearby Heathkit Electronic Center*.
[HeaSiH!
Send for FREE catalog
Write to Heath Company, Dept. 334-734,
Benton Harbor, Ml 49022
In Canada, contact Heath Co., I480 Dundns St. E.,
Mississauga, Ontario L4X 2R7
Heathkit
IBM is a rogistorod trademark ot International Business Machines Corporation. CP/M Is a trademark ol Digital Research, Inc.
transfer rates of either 4800, 2400,
1200, 600 or 300 baud; the function
keys on the keyboard determine
whether the terminal operates in half-
or full-duplex modes. The only ap-
parent deficiency is the lack of a shift
lock key for the terminal mode.
Graphic and Display Features
The display features of the PC-8001
include:
• eight-color display (both text and
graphics);
• 248-symbol character set (complete
Photo 4: Sample display created on the PC-8001 by the authors. Note the use of the
Japanese characters for graphics — the little invaders are actually the Japanese characters
for the word "minute."
Photo 5: Illustration of some of the display restrictions of the PC-8001. See text for ex-
planation.
ASCII, katakana, and graphics char-
acters — lines, arcs, card symbols);
• variable screen format: (80, 72, 40,
or 36 characters by 25 or 20 lines);
• two display modes: text and
medium-resolution (160 by 100 pix-
els) graphics (these two modes can be
intermixed on the same display);
• flashing, reverse video, and
underlined text.
Table 2 lists the graphics and
display-related extensions in the
PC-8001 dialect of BASIC. These in-
clude commands for cursor position-
ing, changing various display pa-
rameters, and plotting points and
drawing lines in gaphics mode. Two
particularly worthwhile instructions
are GET and PUT. GET allows the
user to store the image in a specified
rectangular area of the screen in an
array, which can then be PUT at
another location on the screen. This
allows the user to define complex
shapes that can then be drawn on the
screen with a single instruction.
Repetitive erasure and redrawing of a
shape also provides a simple method
of animation.
Photo 4 is a sample of what can be
done with the PC-8001 graphics. This
display uses most of the commands in
table 2 and, in addition, illustrates the
use of some of the Japanese characters
for graphics purposes (the invader
figures and the television speakers are
made from these characters).
Problems with Video Displays
Upon further experimentation with
the computer, we discovered that cer-
tain graphics operations can some-
times produce strange and unex-
pected results. A sampling of some of
the display anomalies which can oc-
cur is shown in photo 5. The follow-
ing unexpected things happen in this
display:
1. Each column of Xs in the upper-
left corner should be a different color,
but after eighteen columns, the dis-
play remains in one color.
2. The two pairs of intersecting lines
should be the same, but in the one on
the left, extra areas are colored in
near the intersection.
3. The width of the white diagonal
line should stay constant, but it
becomes much thicker in the middle.
4. The two rows at the bottom left
should be all dots, but some of the
dots are printed as text characters.
5. The figure on the right of the
82 January 1981 © BYTE Publications lnc
Circle 47 on inquiry card.
AUdOWDtlD
TOLL FREE 1 -800-528-1 41 8
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tions at eleven switch-selectable baud rates, from 110
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World's low price on the Diablo 630 includes forms
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INTERFACE ON APPLE II AVAILABLE.
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■ ■■■■■■■■■■ Outside Connecticut: ■■■■■■■■■■■,
CALL TOLL FREE:
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From Connecticut Or For Assistance:
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Please send the items checked below:
□ SWEET SIXTEEN kit; No. S-16 (reg. price
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D SWEET SIXTEEN, fully assembled, tested,
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display should be a ring of concentric
squares, each a different color, but
the line thickness varies and some
dots are replaced by text characters.
The explanation for all these
anomalies lies in the way the text and
graphic information is represented in
memory. For example, consider the
full 80-character by 25-line screen for-
mat. To represent a screen of infor-
mation in memory requires storage
space for 2000 characters and their at-
tributes (color, flashing, etc). At 1
byte for the character and 1 byte for
its attributes this would require about
4 K bytes of memory. However, only
3 K bytes are allocated for screen
storage (addresses F300 to FEB8) . The
way these 3 K bytes of memory are
organized explains all these display
anomalies and also provides insight
KEYBOARD/PROCESSOR
UNIT
into a useful feature that makes the
PC-8001 unique.
As shown in figure 3, each row of
characters on the screen is repre-
sented by 120 bytes in memory. The
first 80 of these 120 bytes contain the
ASCII codes for the 80 characters in
the row. The remaining 40 bytes are
organized into twenty pairs. We have
not determined the use of the first
pair, but the remaining nineteen pairs
are used to encode up to nineteen at-
tribute fields for that row. Each pair
Pi points to the beginning of the field,
which runs to position P 1+I — 1 (the
Pi are always ordered so that
Pi<P 2 < ...etc) and contains char-
acters with attributes a, (where a, is
the 1-byte attribute within pair P,).
Whenever a program, in printing
on the screen, uses up the first eigh-
teen attribute fields for a row, all suc-
PC-8001
PC-8041
PC-8043
BASEBAND VIDEO
MONITOR
HIGH-RESOLUTION
COLOR MONITOR
PRINTER
PC-8062
RS-232C
EXPANSION
UNIT
FLOPPY DISK
DRIVES
RS-232C
ADDITIONAL
I/O PORTS
PARALLEL I/O
Figure 2: Interconnection block diagram of the NEC PC-8001 system. While many
peripherals can be directly connected to the PC-8001, disk drives and I/O ports must be
connected through the PC-8011 expansion unit.
84 January 1981 © BYTE Publications Inc
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TELEX: 95 1579
Circle 48 on inquiry card.
BYTE January 1981 85
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Please send the items checked below:
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'.". JAWS 16K RAM fully assembled, tested, burned in.
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□ JAWS 32K RAM kit, No. 6432, (reg. price S329.95),
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No. 6432W, (reg. price S369.95). SPECIAL PRICE
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□ JAWS 48K RAM kit. No. 6448. (reg. price $459.95),
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'All prices plus $2 postage and handling. Connecticut
residents add sales tax.
Total enclosed: $
CI Personal Check □ Money order or Cashiers Check
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Signature
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City
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) Send me more information
cessive characters on the same line
that occur after these fields are given
the attribute a, 9 . This is the default at-
tribute for that row that is set to the
current attributes in effect whenever a
clear-screen command is received.
This explains the first anomaly in
photo 5. After eighteen different-
colored columns, the computer "runs
out of colors," and the remaining col-
umns default to red. Red is not speci-
fied in the program; it just happened
to be the color in effect when the pro-
gram started.
Another problem occurs when
plotting color graphics because the
80
PC-8001 has character-oriented (not
bit-mapped) graphics. (In this re-
spect, it is closer to the Radio Shack
TRS-80 than to the Apple II, for ex-
ample.) Each character space is divid-
ed into a 4 by 2 array of cells, each of
which can be "on" or "off." This pro-
vides an alternate character set con-
sisting of the 256 possible arrays of on
and off cells. When points, lines, or
graphics shapes are drawn, the com-
puter automatically converts the
points to the required graphics char-
acters and displays these, thus pro-
viding an effective graphics resolu-
tion of 160 by 100 cells.
.
o)
65208 ■
120 BYTES
ONE ROW
OF SCREEN
MEMORY
BYTE
80
81
82
83
b)
119
120
CHARACTER CODE 1
CHARACTER CODE 2
CHARACTER CODE 80
POSITION OF FIELD 1
A]
ATTRIBUTE BYTE
P2
POSITION OF FIELD 2
A 2
ATTRIBUTE BYTE
Pl9 POSITION OF FIELD 19
Aj9 DEFAULT ATTRIBUTES
Figure 3: Format of the NEC PC-8001 memory-mapped video display. Figure 3a shows
how each row of the video display translates into a block of programmable memory.
Figure 3b shows how each 80-character row is stored in memory. A row can be broken
into a maximum of nineteen fields, the position and attributes of which are described in
the last 38 bytes of the memory associated with one row. All numbers shown are in
decimal. See the text for further details.
86 January 1981 © BYTE Publications lnc
PUASANI
MEMORY
for f M-SC
users
MT-32
printer/memory module
Give something different this season — the
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The new, brilliantly designed Printer/Memory
expansion module for the TRS-80 Model 1.
This unit will add 16K or 32K of RAM to the
basic 16K machine without the expense of a full
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matrix printer or any other Centronics-
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No hardware modifications. Attaching or
detaching takes seconds. One year warranty.
Three configurations are available:
• Without RAM assembled and tested
(MT-32A @ $119.50)
• With 16K RAM assembled and tested
(MT-32B @ $159.50)
• With 32K RAM assembled and tested
(MT-32C @ $199.50)
Available from Microtek or your nearest
computer dealer.
9514 Chesapeake Drive
San Diego, CA 92123
Tel. (714) 278-0633
TWX 910-335-1269
Outside California
call toll free: 800-854-1087
MICROTEK^
TRS-80 is the Registered Trademark of Radio Shack, Div. Tandy Corp.
Circle 49 on inquiry card.
BYTE January 1981 87
However, a problem occurs when,
for example, two lines of different
colors intersect. Because a character
cannot be two colors at the same
time, the algorithm used by the com-
puter gives the most recently plotted
points precedence. Any cells within
the same character space that are
already "on" are changed to the new
color. Thus, an adjacent pair of hori-
zontal lines for which different colors
are specified may be displayed in
either the same or different colors,
depending on whether or not they lie
on opposite sides of a character cell
boundary. We can show that this is a
limitation of the software and not of
the hardware video-controller device:
the command OUT 63,41 (presum-
ably an output to part of the video-
controller device) fills the screen with
adjacent horizontal lines of different
colors.
This also explains anomalies 2 and
3 in photo 5. The two crosses look
different because they intersect in dif-
ferent positions relative to cell bound-
aries. The white diagonal line changes
width because it crosses a black
graphics rectangle. Even though the
black rectangle is invisible to the
casual observer, it changes the ap-
After you play
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Please send me the "Temple of Apshai" for:
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Disk ($29.95)
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Name
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Aririress
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Charge to: □ VISA □ MasterCard
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Expiration date_
Or charge by phone: (800) 824-7888, operator 861. In Calitornia: (800) 852-7777, operator 861.
If you prefer, call these numbers for a list of the computer stores near you.
pearance of the intersecting diagonal
line: every cell in each character space
changes to white.
This alternative graphics-character
set is selected with one of the bits in
the attribute byte. This implies that
the user can also "run out of
graphics" on a horizontal line. This is
what happens in anomalies 4 and 5
(bottom and far right of photo 5).
The default attribute byte happens to
specify text mode. Hence the remain-
ing characters on the line are dis-
played as their text equivalents.
It is unclear why the designers
chose this display approach, par-
ticularly since a full character- and
attribute-mapped display would have
required only 4 K bytes of memory
instead of 3 K bytes. But even though
this implementation imposes some re-
strictions on the types of displays that
can be generated, it also provides an
interesting capability which, to our
knowledge, is not found on any other
personal computer.
This capability is a consequence of
the fact that the attributes of a char-
acter on the screen are specified in-
directly. That is, each character is
identified with a field number which
in turn is associated with an attribute
byte. Thus, by a direct POKE into
memory (a 1-byte change), the user
can change an attribute (specifically.,
color) of a character or group of char-
acters (up to an entire field) without
altering the character or field codes.
This allows a sophisticated method of
animation called color table anima-
tion in which the user first prints a
number of images in different fields
on the screen, then changes the color
of the fields to make each image ap-
pear in succession. As an example, we
have written a BASIC program which
animates a large flying saucer flying
amidst a field of stars at 20 images per
second. This is very fast for an inter-
pretive BASIC animation.
Summary
The PC-8001 appears to be an at-
tractive, well-planned, and well-
made personal computer. The graph-
ics, though somewhat rudimentary,
are more than adequate for charting,
graphing, and business applications,
and they can do a creditable job on
many games as well. Most people
who have seen our PC-8001 feel that,
if it were sold in this country, it
would provide strong competition for
any of the color-based home com-
puters currently being sold.H
88 January 1981 © BYTE Publications Inc
Circle 50 on inquiry card.
Circle 51 on inquiry card.
Memory — you never seem to have quite
enough of it.
But if you're one of the thousands of Apple
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16K ON A PLUG-IN CARD.
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Together with the SoftCard,
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-L
. . . . -r
■ ■.. i-_l
> 1 . • • — 5
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"Ifllflll
Technical Forum
SC/MP Instruction Set Summary
Professor Walter E Burton Jr
Electrical Engineering Technology Department
Southern Technical Institute
Marietta GA 30060
If you hand-assemble or debug programs for National
Semiconductor's SC/MP processor, here is a simplified
instruction-set summary to speed you on your way.
Table 1 contains the hexadecimal codes, the standard
SC/MP mnemonics, and the SC/MP addressing modes.
Hexadecimal codes are separated into the high-order
digits, which are in the left-hand column, and the low-
order digits, which are in the top row. Mnemonics are
located within the table. The abbreviation PTR refers to
the four SC/MP pointer registers thru 3. The register
numbers are associated with the related instructions in
the same column in table 1.
Different addressing modes associated with two-byte
instructions are located along the bottom of the table.
Blanks identify areas of illegal code.
As a reference I used the SC/MP Technical Descrip-
tion, Publication Number 4200079B (Santa Clara CA:
National Semiconductor Corporation). ■
CO
c
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3
oo
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CD
>.
CD
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3
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CD
>.
m
6
5
1-
High
Hexadecimal
Digit
Low Hexadecimal
Digit
1
2
3
4
5
6
7
8
9
A
B
C
D
E
F
HALT
XAE
CCL
SCL
DINT
IEN
CSA
CAS
NOP
1
SIO
SR
SRL
RR
RRL
2
3
XPAL
XPAL | XPAL
XPAL
XPAH
XPAH
XPAH
XPAH
XPPC
XPPC
XPPC
XPPC
4
LDE
5
ANE
ORE
6
XRE
DAE
7
ADE
CAE
8
DLY
9
JMP
JMP
JMP
JMP
JP
JP
JP
JP
JZ
JZ
JZ
JZ
JNZ
JNZ
JNZ
JNZ
A
ILD
ILD
ILD
ILD
B
DLD
DLD
DLD
DLD
C
LD
LD
LD
LD
LDI
LD
LD
LD
ST
ST
ST
ST
ST
ST
ST
D
AND
AND
AND
AND
ANI
AND
AND
AND
OR
OR
OR
OR
ORI
OR
OR
OR
E
XOR
XOR
XOR
XOR
XRI
XOR
XOR
XOR
DAD
DAD
DAD
DAD
DAI
DAD
DAD
DAD
F
ADD
ADD
ADD
ADD
ADI
ADD
ADD
ADD
CAD
CAD
CAD
CAD
CAI
CAD
CAD
CAD
PTR
1
2
3
1
2
3
1
2
3
1
2
3
CO
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<
Table 1: In
structic
n set s
ummar
y for Nationa
/ Semic
onduc
for's S(
Z/MP
process
or.
90 January 1981 © BYTE Publications Inc
Circle 52 on inquiry card.
*CQ
tfVi
ft **
;. ;
G®^rTD^^ " VPH °"
|8.P
7 DAYS 9-6 I
ORDERS
CALIFORNIA, ALASKA, HAWAI
OUTSIDE OF U.S. (714) 698
NFORMATION, TECHNICA
BORDERS, CALL (714) 698
3 1IL.W S/lli/lnR I
IISIE:
800-854-6654
jcipplc computer
Authorized Dealer
CHRISTMAS
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ACCESSORY SPECIALS
DISK II DRIVE (add-on) 425
D.C. HAYES MICROMODEM II 319
GRAPHICS TABLET 655
INTEGER BASIC OR APPLESOFT II
firmware card 149
SILENTYPE PRINTER with Interface card. . 515
APPLE II ACCESSORIES
APPLE II PLUS
OR APPLE II STANDARD
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w/controller & DOS 3.3
PASCAL
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CENTRONICS PRINTER
Int. card 185
PARALLEL PRINTER Int. card145
COMMUNICATION CARD
w/conn. cable 185
HI-SPEED SERIAL Int. card . . 145
DAN PAYMAR lower case kit. 55
MICROWORKSDS 65
DIGISECTOR 339
LAZER lower case adapter. ... 50
SSM AIO SERIAL/
PARALLEL kit 155
SSM AIO assembled & tested190
SYMTEC LIGHT PEN SYSTEM215
SYMTEC SUPER SOUND
GENERATOR 225
SVA 8 INCH DISK
CONTROLLER CARD 335
VERSA WRITER
DIGITIZER SYSTEM 215
VIDEX VIDEOTERM
80 COLUMN CARD 315
VIDEX VIDEOTERM
w/graphics ROM 335
LOBO DISK DRIVE ONLY... 385
LOBO DRIVE
w/cont. & DOS 3.3 499
GPIB IEEE-488 11978) Int 259
ARITHMETIC PROCESSOR
CARD 335
SPEECHLINK 2000
(64 Word Vocab.) 215
M&R SUP-R MOD
TV MODULATOR 30
CORVUS 10 MEGABYTE HARD
DISK DRIVE SYSTEM
w/pwr supply 4395
CORVUS CONSTELLATION. . 595
16K MEMORY UPGRADE KIT
(TRS-80, APPLE II.
SORCERER 60
ABT NUMERIC INPUT KEYPAD
(specify old or new kybrdl. 115
ALF MUSIC SYNTHISIZER. . . 235
BRIGHTPEN LIGHTPEN 32
M&R SUPER-TERMINAL
80 COLUMN CARD 335
SMARTERM 80 COL 335
Mountain Computer
APPLE CLOCK/CALENDAR
card . 225
SUPERTALKER SD200 SPEECH
SYNTHISIZER SYSTEM. . . . 245
ROMPLUS w/kybrd filter. . . . 165
INTROUX-10 BSR REMOTE
CONTROL SYSTEM 245
INTROL/X-10 controller
card only 165
ROMWRITER SYSTEM 155
MUSIC SYSTEM
(16 voices/stereo) 465
A/D-D/A 16 CHANNELS 319
EXPANSION CHASSIS
(8 slotsl 555
VISICALC 120
CCA DATA
MANAGEMENT. 85
THE CONTROLLER General
Business System 519
THE CASHIER Retail Manage-
ment & Inventory system 199
APPLEWRITERWord
Processor 65
APPLEPOST MAILING
List system 45
DOW JONES PORTFOLIO
EVALUATOR 45
APPLE CONTRIBUTED
Volumes 1-5 w/manuals . . 30
•DESKTOP/PLAN by DESKTOP
COMPUTERS 85
APPLEBUG ASSEMBLER/
DISASSEMBLER 75
APPLE DOS TOOL KIT 65
PIMS Personal Information
Management System .... 23
ADVENTURE by
MICROSOFT 27
SUB LOGIC FS-1
Flight Simulator 34
SARGON II Chess
byHAYDENICass.) 27
FORTRAN 165
DOS 3.3 49
APPLE PLOT .... 60
TAX PLANNER 65
SARGON II Chess
on Diskette 32
TRILOGY OF GAMES 27
SPACE GAME ALBUM 38
SPACE INVADER ICass.l. .18
SPACE INVADER (Disk! ... 23
SYBEX APPLE 80
8080 Simulator 17
FORTH II by PROGRAMMA
SOFTWARE 45
SINGLE DISK COPY
ROUTINES 17
APPLEBUG DEBUGGER. . . 27
APPLESOFT UTILITY PRO
GRAMS BY HAYDEN. ... 27
The CORRESPONDENT. ... 35
ASTEROIDS IN SPACE 19
HEAD-ON 25
3-D ANIMATION PACK 53
BATTLESHIP
COMMANDER 23
FASTGAMMON 26
STAR CRUISER 24
TRANQUILITY BASE 24
More software available
Please write us for a list.
Circle 53 on inquiry card.
EXIDY
ATARI
Please
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For
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Price
SORCERER II
COMPUTER
1B.32K 6 48K VERSIONS AVAILABLE
S 100 EXPANSION UNIT 375
WORD PROCESSING PAC 179
DEVELOPMENT PAC 89
PMC-80
ȣ*,
THE TRS-80 WORK-ALIKE'
16K LEVEL II ONLY $579
Completely compatible with Radio Shack TRS-80
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Level II Basic, Video & Ch. 3 TV output. Buil!
in Cassette, 40 pin interface conn., 16K User RAM
memory, Expandable to 48K.
For more information, ploase call or writs.
ATARI
16K for /5I5J
ATARI 800
PERSONAL COMPUTER SYSTEM
400 COMPUTER 479
820 PRINTER I40 col. 1 459
810 DISK DRIVE 559
410 PROGRAM RECORDER 59
815 DUAL DISK DRIVE 1199
822 THERMAL PRINTER (40 col. 1 369
825 PRINTER (80 col. imp. 1 795
850 INTERFACE MODULE 175
ATARI 16K RAM MODULE 155
LIGHT PEN 65
ACOUSTIC MODEM ICATI 169
COMPUTER CHESS 35
SPACE INVADERS 19
STAR RAIDERS 49
SUPER BREAKOUT 35
3-D TIC-TAC-TOE 35
VIDEO EASEL 35
MUSIC COMPOSER 49
VISICALC DISK 129
OSI
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»799
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PLOTTERS VIDEO MONITORS
*1095
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tor more info please call or write
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SANYO 9" B&W 165
SANYO 12" B&W 255
PANACOLOR 10" COLOR 329
NEC 12" HI-RES COLOR 875
NEC 12" LORES COLOR 399
NEC 12" GREEN PHOSPHER(P3il . . 239
TELEVIDEO 912B&C 698
TELEVIDEO 920B & C 745
Cassette Disk
SPACE INVADERS 19 29
SARGON II 30 35
FORTH N/A 69
OS 65-D V3.3 N/A 79
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dac I N/A 45
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PASCAL & FORTRAN (4P 6 8P only! . N/A 450
When orderina Dlease SDGcifv system.
PRINTERS
ANADEX DP 8000 775
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NEC SPINWRITER 2550
TRENDCOM 200 519
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EPSON TX-80 w/graphica 729
EPSON MX-80 132 col 620
QUME SPRINT 5 2550
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Circle 53 on Inquiry card.
System Review
The Sinclair Research ZX80
John C McCallum, Department of Computer Science
York University, 4700 Keele St
Downsview, Ontario, M3J 1P3 Canada
The new ZX80 microcomputer from Sinclair Research
Ltd is a remarkable device. Although first announced to
the North American public in February, 1980, the
microcomputer did not become available until the fall.
During the wait, the price has dropped from the expected
$245 to just under $200. Because of this, the ZX80 is being
Name
Other hardware features
Sinclair ZX80
Forty-key pressure-
sensitive keyboard; built-
Manufacturer
in RF (radio-frequency)
Sinclair Research Ltd
modulator (for channel
475 Main St
2); creates video display
POB 3027
of 24 lines of 32
Wallingford CT 06492
characters each; includes
(617) 367-1988
AC adapter, cables to
cassette recorder
Price
$199.95
Software
4 K-byte system ROM,
Dimensions
which includes a BASIC
15.9 by 20.8 by 3.7 cm
interpreter and necessary
(6Vi by 8Vz by V-A
internal software
inches)
Options
Processor
8 K-byte BASIC module
Z80A, 8-bit
and 16 K-byte program-
mable memory module
System clock frequency
(see "New Sinclair
3.25 MHz
Modules" text box for
details)
Memory
1 K-byte static memory,
Comments
4 K-byte system ROM
Contains introductory
(includes BASIC inter-
BASIC book, A Course
preter)
in BASIC Programming,
128 pages, 20 by 14 cm
Mass storage
(8V4 by 5 3 /4 inches)
Uses standard cassette
recorder (not included)
widely advertised as the first personal computer for
under $200.
The ZX80, shown in photo 1, is a new design from
Clive Sinclair, a well-known British electronics in-
novator. Sinclair is best known for his previous products:
a miniature television, low-cost calculator and digital
watch kits, and miniature stereo components. All of his
products have stressed small size, low cost, and high-
quality operation — usually at the expense of packaging.
The same is true of the ZX80.
Can it be any good if it sells for under $2007 This is a
reasonable question, but the question that is most impor-
tant when buying a computer is, "Will it do the job I want
it to do?" The only way to tell is to look at its features in
some detail. In order to design a very low-cost computer,
some features had to be cut. However, the new features
that have been added are rather impressive. The good
features include low price, small size, high micropro-
cessor speed, ease of program entry, and real-time BASIC
syntax checking.
The price of $199.95 includes the assembled computer,
an AC (alternating current) power adapter, a cable to
connect the ZX80 to a standard television set (channel 2),
connectors for a cassette recorder, and a well-written
book on programming in BASIC for the ZX80. For those
interested in building kits, a kit version is available.
However, you will not save money by doing so, and the
kit involves some steps that are rather involved for an in-
experienced kit builder.
The ZX80 is small. The actual dimensions are 15.9 by
20.8 by 3.5 cm (6V2 by 8V2 by IV2 inches), or about the
size of a hardcover book. It is not the smallest personal
computer — the new pocket computers from Sharp, Pana-
sonic, Quasar, and Radio Shack have that honor. Also,
because the ZX80 has to be attached to its AC adapter
and a television set to work, some of its size advantage is
lost.
As part of this evaluation, several benchmark pro-
grams were run in BASIC to compare the ZX80 to other
personal computers. Although the ZX80 is not as fast as
advertisements imply, it does run faster than many other
personal computers, including the Radio Shack TRS-80
Model I.
94 January 1981 © BYTE Publications Inc
"1
'What You Don't Know
Won't Hurt You". Couldn't Be
Further From The Truth
When It Comes To Running Your
Own Business.
How far from the truth is the
adage that says "What you
don't know won't hurt you."
Systems II is designed to
give you the advantage. Its up-
dated methods and program-
ming procedures will take you
out of the "pencil pushing" age
and into "today's technology".
The Reasons For Systems II
The number one reason
is dependability.
At Applewest Inc. we have
put the system through its
paces. However no matter how
much "in-house" testing is
done the true test comes from
the end user — like yourself.
We listened to our customers
and we learned.
Here Is What We Found Out
The small businessman
wants big performance from
his micro system, not micro
performance. He wants com-
plete documentation that is
easy to use. He wants com-
plete flexibility to grow into a
more advanced system. He diskettes, standard eight inch
wants the availability of addi- disk or a ten megabyte hard
tional programs so he won't be disk. Programs are continuous-
boxed in. Last, but not least, he ly being developed to expand
wants support for any pro- the usability of our system,
blems he may have. See your local dealer today.
Here Is How We Responded If he doesn't have SYSTEM II
To expand the performance have him give us a call.
Of the already Super Apple II, Systems II - Apple II - And You
the KSAM (keyed sequential ac- Moving Your Business Forward
cess method) was developed Faster.
for fast aCCeSS tO any reCOrd 2455 s.W. 4th Ave., Suite 2, Ontario, Oregon 97914
on file, giving performance that P03)88i-ii47 .^
even larger systems find hard ,-
to beat. ^.tfrjpv
Our documentation is the ^P^^f-
most complete of any on the '-'-^
market. Our Operations Manual
explains in depth the use of
each module in the system, but
we didn't stop there.
A Lesson Manual/User's W&m
Guide was developed =_
taking the user through — = = == ■= |s^ i , = ; f ! g= =r : |
ted, learning process. = ==T~
SYSTEMS II is avail- SoFtUIOfC Inc.
able On five and One quarter Apple ll is a trademark of Apple Computers
High
Technology
Have you heard"?
The Cashier* has been
promoted to
The Store Manager.
The Cashier has so much more to offer
than its name implies that we decided to
give it a new name. This valuable software
package can save time and increase profits
for small business owners by providing:
• real-time inventory control
• point-of-sale functions
• customer & vendor address lists and
mailing labels
• informative management reports
• up-to-the-minute sales monitoring
• invoices, quotations, & packing slips
• purchase orders & receiving reports
• daily, monthly, and year-to-date sales totals
• physical inventory checklists
• and much, much more.
But what can you call a software package
for the Apple II* that does so much? You
might call it 'remarkable' ... we call it
The Store Manager.
Drop by your local
computer store and
see what The
Store Manager
can do
for you.
High
Technology, Inc.
P.O. Box B-14665
8001 N. Classen Blvd.
Oklahoma City. Oklahoma 73113
405 840-9900
•Apple II and The Cashier are trade names ol Apple Computer Inc
Photo 1: A photograph of the ZX80 in operation. The
homemade power supply gives an indication of the small size of
the computer. At the bottom of the television set, a BASIC line
is being edited.
The ZX80 also has a few software features that are
useful. The single-keystroke keywords mean that, instead
of typing a whole word, you have to type only a single
character on the keyboard. This can cause some confu-
sion at first, and it takes some time to remember not to
type the whole word. But it does speed up the typing pro-
cess when entering a program. Because the keywords are
stored in 1 byte each, you save memory space that can be
used for extra program storage.
Another BASIC feature that I found impressive is the
syntax checking of the program as you type it in. 1 have
always been disappointed that most other versions of
BASIC do not do this. The ZX80 actually prompts you
with the type of input it is looking for — a keyword, a
literal, a string, or a number. If you enter an illegal state-
ment, it indicates where the statement is wrong and will
not let you enter that statement into the program. It also
does a similar check on input data requested by a running
BASIC program. In fact, it allows you to enter simple ex-
pressions for numeric input and calculates the value while
reading the value into the program; a very nice feature.
At $200, though, everything cannot be optimum.
There are objectionable features too. The most annoying
or limiting features of the ZX80 are its small memory
size, screen blanking during program execution, its
limited BASIC, and its keyboard.
The ZX80 comes with 1 K bytes of programmable
static memory, although a memory-expansion board
allowing 16 K bytes of memory is expected soon (see text
box). These 1024 bytes of memory are shared by system
variables, your BASIC program, the program variables,
working space, the video-display memory and the stack.
Although the space is used very efficiently, 1 K bytes of
memory do not store a large program, no matter how
efficiently it is squeezed.
Perhaps the most limiting characteristic of the ZX80 is
the screen-blanking behavior. When the ZX80 is ex-
ecuting a program, the TV screen goes black. This hap-
pens because the processor is used to control the display
as well as to do the processing, and the design decision
was made to have the processor devote its time to only
one of these. The effect of this trade-off is to increase pro-
Circle 54 on inquiry card.
Circle 55 on inquiry card.
H
■mi
dalasoulh announces. ••
THE TOTAL PRINTER PACKAGE!
!
With so many matrix printers on the market today, it may seem
tough to find exactly the right one for your application. Some
models may offer the speed you need, others the communications
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printer offers all the features you need... until now.
The DS180 matrix printer provides the total package of perfor-
mance features and reliability required for applications such as
CRT slave copy, remote terminal networks and small to mid-range
systems. Not a "hobby-grade" printer, the DS180 is a real work-
horse designed to handle your most demanding printer require-
ments. And pricing on the DS180 is hundreds of dollars below
competitive units.
High Speed Printing -Bidirectional, logic-seeking printing at
180 cps offers throughput of over 200 Ipm on average text. A
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a 9x7 matrix with true lower case descenders and underlining.
Non-volatile Format Retention -a unique programming keypad
featuring a non-volatile memory allows the user to configure the
DS180 for virtually any application. Top of form, horizontal and
vertical tabs, perforation skipover, communications parameters
and many other features may be programmed and stored from the
keypad.When your system is powered down/the format is retained
in memory. The DS180 even remembers the line where you stopped
printing. There is no need to reset the top of form, margins, baud
rate, etc. . . . it's all stored in the memory. If you need to recon-
figure for another application, simply load a new format into the
memory.
Communications Versatility -The DS180 offers three interfaces
including RS232, current loop and 8-bit parallel. Baud rates from
110-9600 may be selected. A 1K buffer and X-on, X-off hand-
shaking ensure optimum throughput.
Forms Handling Flexibility -Adjustable tractors accommodate
forms from 3"-15". The adjustable head can print 6-part forms
crisply and clearly making the DS180 ideal for printing multipart
invoices and shipping documents. Forms can be fed from the front
or the bottom.
If you would like more information on how the DS180's low-cost
total printer package can fill your application, give us a call at
Datasouth. The DS180 is available for 30-day delivery from our
sales/service distributors throughout the U.S.
data©®*
computer corporation
4740 Dwight Evans Road • Charlotte, North Carolina 28210 • 704/523-8500
2a
1 REM
S REM CKhRRCTER SET
3 PRINT " "
4. PRINT " "
SSPRINT - "
lO FOR 1 = 1 TO 2SS
20 PRINT CHR* 1 1 ) ;
30 NEXT I
- ZXSO
fa
2b I
1
j"£J% ■J»»*£$:?<l-+X>'=><; , .01S345
e.TQgflSCOEFGHIOKUMNOPORSTUVWXYZ??
THEN TO ; , ) C
NOT -*X/ AND OR XI=>< LIST RETU
RN CLS DIM SRVE FOR GO TO POKE I
NPUT RhNDOMISE LET •?? NEXT PRINT
? NEW RON STOP CONTINUE IF GO S
U8 LORD CLERR REM f
0/30
Photo 2: The character set of the ZX80 computer. Photo 2a
shows a program that will list all 256 characters used by the
ZX80. Photo 2b shows the character set produced by the pro-
gram; note that some characters are expanded to multiletter
keywords and that undefined codes are represented by a ques-
tion mark.
cessing speed at the expense of limiting the interactive
quality of the ZX80. It is not going to have the same types
of games as the Commodore PET or the Apple II com-
puters. However, when performing long calculations on
the ZX80, it is easy to tell when the program ends — the
room bursts into light!
The limited features of ZX80 BASIC are also
frustrating. This is a result of the limited amount (4 K
bytes) of ROM (read-only memory) available. This mem-
ory contains the software used for the BASIC interpreter,
for the character generator for the TV display, for de-
coding the keyboard, and for cassette reading and writ-
ing. This squeeze results in many useful BASIC functions
being omitted.
When dealing with strings, for example, you can break
up a string using two functions: CODE gives the ASCII
(American Standard Code for Information Interchange)
equivalent of the first character of the string; the TL$
(tail) function returns a string containing all but the first
character of the string. As an example of functions left
out, you cannot put two strings together (no concatenate
operation or function exists). However, Sinclair intends
to bring out an optional 8 K-byte floating-point BASIC
on a single ROM. With more than double the space to
work with, it should be a very rich and impressive
language.
The last feature that I find annoying is the keyboard. It
works — but @"#$. It is a touch-sensitive key-
board — smooth, washable, indestructible. But it is dif-
ficult to keep your fingers positioned properly on the
keys, particularly on the shift key, without inadvertently
pressing an extra key or two. The hardest keys to use are
the cursor controls and the rubout keys (both are shifted
characters). I always seem to end up with zeros where I
want to remove a character (rubout is shift-zero). Re-
member, though, that some people pay more for a key-
board than this entire computer costs. This was a very
wise place to save money on the design.
iOO REM BENCHMRRK PROGRfiM 7
SOO PRINT "START "
AOO LET K=0
<K30 DIM M(S)
500 LET K=K+1
51CHLET R=Kvax3+*-5
520 GO SUB 820
5GO FOR l_=l TO S
SOS LET M(L)=R
SAO NEXT L
BOO IF - K<1000 THEN GO TO SOO
VOO PRINT "END"
SOO STOP
820 RETURN
510 LET BR=K/ , axa-»*-s
Photo 3: Editing on the ZX80. The cursor (at line 510 at the top
of the screen) can be moved via arrow keys to different lines of
the program. When the Edit key is pressed, the line being
pointed to is copied at the bottom of the screen, where it can be
edited. The cursor on the bottom line can be moved right and
left; characters can be deleted or inserted at the current cursor
position. When the Newline key is pressed, changes made in this
line are added to the existing program.
Some Technical Details
The ZX80 microcomputer uses a very efficient design
with a total of only twenty-two standard integrated cir-
cuits, including the voltage regulator. The main pro-
cessor is a Z80A processor running at a speed of about
3.2 MHz. The programmable memory is a pair of 4 K-bit
static memory devices. The ROM is a single 4 K-byte
part that includes both the BASIC interpreter and the
other functions listed above.
The operation of the ZX80 is — so far as I understand
it — quite complicated because it works on a mix of hard-
ware and software. The overall concept is that the refresh
counter of the Z80 is used to control the generation of the
lines of the video display, producing dots on the TV
screen at twice the frequency of the processor clock. The
keyboard is scanned under software control as I/O (in-
put/output) port number 1, a port that is also shared by
the cassette input circuitry. The cassette output signal is
the same as the video synchronization signal; it is also
under software control. It is an interesting design, but
you will need to study the ZX80 ROM carefully before
you can really understand it.
The character set is also a little strange. The keywords
that are entered with single strokes are stored as single
tokens and are expanded when displayed. Photo 2 shows
98 January 1981 © BYTE Publications Inc
OOmWJTER UJnREHOUg
CALL TOLL FREE 1-800~528-1054
ATARI
800 (16K) $775
400 $440
810 Disk Drive $520
825 Printer $750
850 Interface $160
16K Memory $110
410 Recorder $ 70
830 Modern $145
Star Raiders $ 45
Software From $ 10
Special 32K 800 System
800 w/32K, recorder
star raiders, joystick
MODEMS
Lexicon
LEX-II
Novation
CAT
D-CAT
MONITORS
APF - 9" Monitor
Sanyo - 9" Monitor
VIDEO TERMINALS
Hazeltine
1500
1420
Soroc
IQ 120
IQ 140
Televideo
912 B
912 C
920 B
920 C
Zenith -Z- 19
PRINTERS
Centronics
730 Serial
730 Parallel
737 Serial
737 Parallel
Diablo
1640 630 $2400
1650 Call
Epson-MX-80 Call
NEC
5510 Call
5520 Call
Okidata - Microline 80 $524
Qume
5/45 Call
5/55 Call
Teletype
Model 40 Call
Model 43 w/Pinfeed $1 005
Texas Instruments
810 Basic. . .• $1516
810 Loaded $1739
820 KSR Basic $1732
820 KSR Package $1916
Circle 56 on inquiry card.
$970
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COMPUTERS
Aitos Call
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Northstar
HRZ II-32K D (Assm) $2300
HRZ II-32K Q (Assm) $2665
Zenith
Z-89 48K $2210
DISKETTES
BASF
5'/4-0 Sector S/S D/D (Qty 10) $33
5%-10 Sector S/S D/D (Qty 10) $33
5V..-10 Sector D/S D/D (Qty 10) $37
Memorex
5'/4-10 Sector S/S D/D (Qty 10) $27
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5V4-10 Sector S/S D/D (Qty 10) $37
5VS-10 Sector D/S D/D (Qty 10) $42
Scotch
5%-0, 10, 16 Sector (Qty 100) $275
8"-0, 32 Sector (Qty 1 00) $275
BUY, SELL, TRADE
Experienced Equipments
Soroc IQ 120 . . $500 Centronics 779
Tl 810 Basic . . $1200
TVI 912 $550
TVI 920 $600
Qume Call
Diablo Call
Centronics 730
Teletype 40 $3400 NEW
Comprint $400
Z-89 Call
Sanyo 15" Monitor $195
Prices reflect 3% cash discount. Product shipped
in factory cartons with manufactures warranty. Add
2%, a minimum of $5, for shipping and handling.
GOmPUTCR
fl
WAREHOUSE £3
2222 E. Indian School Rd. • Phoenix, Arizona 85016
(602)954-6109
Store Hours: Tues.- Friday 10-6 MST Saturday 10-5 MST
BYTE January 1981 99
a program for generating all 256 codes.
The high quality of the black-and-white display can be
seen in the photograph of the TV screen, which is a stan-
dard 12-inch color TV set (see photo 2b). The question
marks are undefined codes, and the keywords (which are
spelled out) are fairly obvious. The graphics characters
allow a limited 46- by 64-pixel graphics resolution.
However, since the ZX80 is not primarily designed for in-
teractive graphics applications, the existing resolution on
the ZX80 should be sufficient.
Software Features
The ZX80 system is excellent for learning introductory
programming concepts. This is in large part due to the
immediate feedback about errors. For the student at the
introductory level, the limited features of the language
are useful in preventing confusion; compare this with the
extreme detail taken to describe some complicated ver-
sions of BASIC. When you are ready to progress at a
later time, the expanded version of BASIC will be
available.
ZX80 BASIC not only prevents you from making syn-
tax errors, but it also prompts you with a cursor that tells
you what it is expecting — a keyword (denoted by a K in-
side the square cursor) a literal (denoted by an L), or a
numeric literal (denoted by an LS). When a program is
expecting string input, it puts the cursor between quotes,
then expands the quotes as you enter the text. With the
ZX80, you never get the string errors during data entry
that are so common with other personal computers.
The method of editing programs is also well planned.
A cursor, controlled by the t and I cursor keys, is used to
text.
Sine
e lines
nre
octer
, words, lin
» or
anywr
n the
text
opens
up
or clos
s as
rioge
retu
ns as
well
since
each
line of
tex
the electric pencil II
% for the TRS-80 Model II* Computer
OEM
The Electric Pencil is o Character Oriented Word Processing
System. This means that lex! is entered as a conlinuous siring
of characters aid is manipulated as such. This allows the user
enormous freedom and ease in the movement and handling of
not delineated, any number of char-
' paragraphs may be inserted or deleted
. The entirety of I he text shifts and
; needed in full view of the user. Cor-
as word hyphenation arc not requi red
t is formatted automatical ly.
As text is typed and (he end of o screen line Is reached, a
portiolly completed word is shifted to the beginning of the
following line. Whenever lext is inserted or deleted, existing
lext is pushed down or pulled up in a wrap around fashion.
Kverylhing appears on the video display screen as it occurs
(hereby eliminating any guesswork. Text may be reviewed ot
will by variable speed or page-at-o-time scrolling both in the
forward aid reverse directions. By using the search or the
search and replace function, ony string of characters may be
localed rnd/or replaced with any other string of characters as
desired. Specific sets of characters within encoded strings
may also be located.
When text is printed, The Electric Pencil automatically
inserts carriage returns where they are needed. Numerous
combinations of Line Length, Page Length, Character Spacing,
Line Spacing end Page Spocing allow for any form to be
handled. Right justification gives right-hand margins that
are even. Pages may be numbered as well as titled.
the electric pencil
n Wuitl Pin
i, SyitM!
The TRSDOS versions of The Electric Pencil II are our best
ever! You can now type as fast as you like wilhout losing any
characters. New TRSDOS features include word left, word right,
word delete, bottom of page numbering os well as extended
cursor controls for greater user flexibility. BASIC files may
also be written end simply edited without additional software.
Our CP/M versions are
the some as
we have bee
distributing
for several years end alio
* the CP/iV
user to edi
CP/M files
with the addition of our
CONVERT
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n additional
S35.0Q. CONVERT is not
required if
ally quick tnd easy word
processing is required. A
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CP/M
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Features
TRSDOS or CP/M Compatible ' 5upoorls Four Disk
Drives * Dynamic Prim Formatting ' Diablo, NEC A
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Value Chaining ' Page-ot-a-l ime Scrolling •
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1-lrmb.T Tally * Global Search & Replace • Full Margin
Control • End of Page Control ■ lion Printing Text
Commenting * Line & Paragraph Indentation ■
Centering • Underlining • Boldface
The Electric Pencil I is still available for TRS-80 Mode! I
users. Although not as sophisticated as Electric Pencil II, it
is still an extremely easy to use and powerful word processing
system. The software lias been designed to be used with both
Level I (I6K system) and Level II models of lite TRS-80. Two
are available an cassette. The TRS-80 disk version is easily
transferred to disk end is fully interactive with the READ,
WRITE, DIR, and KILL roulines of TRSDOS,
MICHAEL SHRAVER SOFTWARE, INC,
1198 Los RoblesDr
Palm Springs, CA 02262
(714) 3231400
point to the "current" line. When the Edit key is pressed,
the current line moves down to the bottom of the screen
to the program-entry line. There is always at least one
line between the program and the text-entry line, so you
will not get the areas confused.
Once the line is in the program-entry area, the line is
treated exactly like a program line that you are typing ex-
cept that the cursor is at the beginning of the statement.
The cursor control keys — and -* are used to move the
cursor within the line. Typing anything just inserts it at
that point in the line, and the rubout key is used to delete
the previous character. When you are finished editing,
just press Newline and the edited line replaces the old line
in the program (see photo 3). If you modify the line
number during editing, you create a new line in the pro-
gram. This feature makes it very easy to duplicate lines in
a program.
The best way to describe the features of the ZX80
BASIC language is to add to the comparison table used
by Creative Computing in their "BASICs Comparison
Chart" (July 1980 issue, pages 28 and 29). The major
features of the Sinclair Research ZX80 4 K-byte BASIC
are given in table 1.
Performance of the ZX80
At some time, all users become concerned about the
speed of their computers. There is no simple way to com-
pare the speed of various personal computers without
running actual programs. Two standard benchmarks
have been used to compare a wide range of computers
running BASIC. These have been run on the ZX80 to get
a valid estimate of its speed.
The system clock frequency of the Z80A processor is
3.2 MHz. This compares to about 1.77 MHz for the
Radio Shack TRS-80 Model I or to the 4 MHz of the
TRS-80 Model II, both of which also use the Z80 as the
main processor. A Z80 running at 2 MHz should be
Integer variables
yes; names must contain letters and
numbers only, but can be any length.
Real variables
no
String variables
yes; names must be one letter fol-
lowed by a dollar sign (eg: AS, B$, ...,
Y$, Z$).
Arrays
integer and one-dimensional (eg:
C(N)) only; names must be one letter
long and are initialized to zero
values.
Arithmetic operations
performed on 16-bit signed integer
values.
Arithmetic operations
+ ,-,*,/,** (exponentiation)
Relational operations
= ,>,<, on either string or integer
argument pairs.
Boolean operations
NOT , AND , OR performed on cor-
responding bits of integer arguments.
String operations
CHR$(X), TL$(X$), STR$(X$)
BASIC statements
CLEAR, CLS, DIM, FOR, GOSUB, GO
TO, HOME, IF, INPUT, LET, NEXT,
POKE, PRINT, RANDOMIZE, REM,
RETURN, STOP
BASIC expressions
ABS(X), CODE(X$), PEEK(X), RND(X),
USR(X)
BASIC commands
CONTINUE, EDIT, LIST, LOAD, NEW,
RUN, SAVE
Graphics
20 graphics characters; effective
resolution is 46 rows of 64 squares
per row, plus some graphics
characters for shading.
Table 1: Summary of the Sinclair Research ZX80 4 K-byte
BASIC.
100 January 1981 © BYTE Publications Inc
Circle 57 on inquiry card.
WHYCIS COBOL
LETS TOUR
MICROCOMPUTER
PERFORM LIKE A
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Now, you can use a microcomputer for
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CIS COBOL is Micro Focus' Compact,
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offers the advantages of COBOL . . .
powerful data structure features, English-
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commercial language. You won't be
restricted by size either: a 64K byte
microcomputer will compile up to 8000
lines of COBOL, more if the program's
split into dynamically loaded modules.
Choose a Compact Compiler.
The Compact compiler runs on 32K byte
microcomputer systems. Its powerful
subset includes full support for random,
indexed and sequential files.
Or choose the
Standard Compiler.
The Standard CIS COBOL compiler
requires a minimum 48K of user RAM.
A super-set of the Compact compiler,
implementing ANSI 74 COBOL to
Federal Low-intermediate Level.
The same CIS COBOL
extensions for conversational
working, screen control, interactive
debugging, and special peripheral sup
port are in both compilers. And there are
more reasons to consider CIS COBOL:
• It conforms fully to the ANSI 74 stand-
ard, so programs are portable upwards
and downwards to minis or mainframes.
• Its interactive features enable main-
frame programmers to get results fast . . .
workingon inexpensive microcomputers.
Forms
The FORMS utility lets you build a
screen layout online at the CRT. Then
it automatically generates COBOL
record descriptions for inclusion in your
program.
Forms-2
A superset of FORMS, it eliminates the
need to write simple data entry and
inquiry programs, because the programs
can be automatically generated from
screen definitions.
Environment
CIS COBOL products run on the 8080
or Z80 microprocessors under the CP/M*
operating system, and on the LSI-11
or PDP-11 processors under RT-11.
They are distributed in a variety of disk
formats and come with a utility that
enables you to use any make of CRT.
OEMs
Intel has adopted CIS COBOL and offers
it (as iCIS-COBOL) for their Intellec and
Intellec II systems. Ideal
for OEM's or private label,
CIS COBOL was developed
"entirely by Micro Focus. Send
inquiries for CIS COBOL object packs
and application vendor terms to MICRO
FOCUS or its licensed distributors.
Distributor terms also available from
MICRO FOCUS.
______________^
Send me more information for: bi I
□ Single Copy Users
□ Reseller and Distributor Licensing
Name
Title
Company
Address
City/State
Zip/Phone
Computer Model.
Version of DOS_
MICRO FOCUS
Micro Focus Inc. ■ 1601 Civic Center Drive •
Santa Clara • CA 95050 • Tel: (408) 984-6961 •
Telex: 171-135 MISSION SNTA
U.K. Office • 58 Acacia Road • St. Johns Wood •
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CIS COBOL distributors include: Vector Graphic, Onyx Systems. Altos Computer Systems. Lifeboat Associates. Research Machines, Telecomputing, Modular Business Systems. Rair, Midlectron.
Roslronics and Johnson-Laird Inc. tlntellec is a trademark of Intel Corp. *CP/M is a trademark of Digital Research Inc.
Circle 58 on inquiry card.
BYTE January 1981
101
Benchmark
Number 12 3 4 5 6 7
Execution
Time (Seconds) 1.6 4.7 9.0 8.5 12.2 25.3 38.5
Table 2: Execution times of BASIC benchmark programs on
the Sinclair ZX80. See text for details
similar in speed to a 6502 running at 1 MHz (as used in
the Commodore PET or the Apple II). These estimations,
however, do not consider the efficiency of the BASIC in-
terpreter, which is often the most important speed factor.
Thus, the execution-timing test of actual BASIC bench-
mark programs is the most important way of comparing
the speed of various personal computers.
The ZX80 ranked between second and third places in
the BASIC benchmarks done for Kilobaud magazine (see
"BASIC Timing Comparisons" by Tom Rugg and Phil
Feldman, October 1977, page 20). It was beaten only by a
6502 microprocessor running at 2 MHz (an Ohio Scien-
tific Challenger II running its 8 K-byte BASIC), and by a
Z80 running at 4 MHz (Zapple 8 K-byte BASIC). For
those interested in the actual times of the benchmark pro-
grams, they are given in table 2.
The prime-number program used for benchmarking
BASIC processors by Interface Age was also run (see
"Assignment: Benchmark," by Tom Fox, June 1980, page
130). [A similar benchmark program was given in
"TRS-80 Performance: Evaluation by Program Timing"
by James R Lewis, on page 84 of the March 1980
BYTE....GW] This benchmark is particularly interesting
because it was run on several of the fastest small com-
puters, as well as on a DEC (Digital Equipment Corpora-
tion) PDP-10 computer. The program given in the Inter-
face Age article had to be modified slightly to allow for
integer BASIC. However, the only major effect was to
change an INT function to an integer multiply. The ex-
ecution time for the program running on the ZX80 was
1604 seconds. Although this was not very fast compared
with many of the computers in this benchmark, it was
not the slowest either (the TRS-80 Model I took 1928
seconds). The execution time was decreased to 1513
seconds by removing the comment statements from the
program (a 5 % increase in speed) . This is a typical way of
speeding up BASIC interpreters.
The ZX80 might be summarized as a high-perfor-
mance, very low-cost, portable personal computer sys-
tem. It is best used for home or school use in learning the
concepts of programming. When the memory-expansion
and floating-point-BASIC modules become available (see
the "New Sinclair Modules" text box), it will also be good
for low-cost mathematical, scientific, and engineering ap-
plications. If you are looking for your own home com-
puter, the ZX80 is a good starting point. ■
New Sinclair Modules
As this article goes to press, Sinclair Research Ltd
has announced two new modules for the ZX80, an
8 K-byte BASIC in ROM and a 16 K-byte program-
mable-memory module. According to an American
representative of Sinclair Research Ltd, the pro-
grammable-memory module and a later version of the
BASIC module currently being sold in England will
probably be available soon on the American market.
The prices are expected to be "under $100" for the
16 K-byte programmable-memory module and "about
$40" for the 8 K-byte BASIC module. The BASIC
module will be slightly different from the one now be-
ing sold in England in that it will add printer support
to the ZX80.
-ZX80
References
1. Davenport, Hugo. A Course in BASIC Programming-
Operating Manual. Sinclair Research Ltd, 1980.
2. "Personal computer looks to open up the market with an ultralow
price." Electronics, Volume 54, Number 4, February 14, 1980, pages
80 thru 82.
1 Trademark of Western Digital. ; -j
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Copyright ©1980.
Digicomp Research
All rights reserved.
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102 January 1981 © BYTE Publications Inc
Circle 59 on inquiry card.
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with your company's money.
Our entry level computer system is the first step in
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expense of new hardware and software when
you outgrow your current system.
You'll beabletodo low cost word processing,
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For information contact Vector, 31364 Via Colinas,
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Economy Sized Computers
Circle 60 on inquiry card.
BYTE January 1981 103
Education Forum
Multi-Micro Learning
Environments:
A Preliminary Report on the
Solo /NET /works Project
Dr Thomas A Dwyer, Soloworks Laboratory,
University of Pittsburgh, Department of Computer Science,
Pittsburgh PA 15260
Inventive Learning
It's a good idea to "back off" occasionally from the
tough problems of education in the real-school world
and spend some time thinking about what it would take
to develop learning systems that go beyond training in
the basics. In particular, it is valuable to contemplate the
intricacies of some of the impressive natural-learning
phenomena that surround us. For example, when a two-
year-old child startles her parents by speaking an adult-
sounding sentence (one recently heard was, "No garage
sales today — that's ridiculous") it's worth contemplating
the significance of such a minor miracle as a key to
understanding later cognitive developments. In a similar
manner, when a six-year-old masters the "solution" to a
complex system of differential equations in the eminently
practical form of learning to ride a bicycle, we should
spend more than a few moments asking what made such
a remarkable conquest possible.
An examination of these and similar examples of com-
plex human learning reveals that in addition to the intrin-
sic (and still quite mysterious) human potential for
developing an ever expanding "life of the mind," there are
two important external elements at work. These elements
can be described as supportive-social and supportive-
physical environments. In the case of the loquacious two-
year-old quoted above, the supportive-social environ-
ment was the constant flow of conversation between
parents and child as they made their rounds of local
garage sales in search of fun bargains. The supportive-
physical environment was the set of real places that were
visited as the child took part in the fascinating process of
finding and acquiring some well-remembered objects, in-
cluding, of course, a few toys.
The learning-to-ride-a-bicycle phenomenon is sup-
ported from the same two bases. The social environment
is the neighborhood full of other kids who can handle a
two-wheeler and the fun that is promised to anyone who
can participate in the local rites of pedal-pushing. The
physical environment is the pavement on which to pedal
and of course the bicycle. When similar examples con-
nected with older students are analyzed (eg: learning to
fly an airplane solo in 10 hours), it is evident that the
Photo 1: Students from a local high school learn to play N-Trek.
The terminals being used were connected to a PDP-11 RSTS
time-sharing system, with each terminal controlling a job
related to a function of one starship crew member. The jobs in-
teracted through use of shared variables in a common segment
of memory.
heritage of ideas built into complex mechanisms is often a
crucial part of supportive-learning environments.
It was another example of such environmentally sup-
ported human learning that triggered the idea behind the
Solo/NET/works project. The example came out of
something called the Soloworks project in the mid 1970s.
The Soloworks project involved the use of computer
technology to support a complex multiplayer version of
the popular game Star Trek. (See photo 1.) Written by
student Don Simon, the game was nicknamed N-Trek.
This was because it allowed a variable number of players
to interact in a cooperative simulation /game setting.
In its original version, N-Trek was run on a PDP-11
minicomputer time-sharing system. The general idea of
the game was similar to more conventional versions, with
the starship Enterprise commissioned to explore the
unknown while doing battle with the evil Klingon forces.
The big difference was that in N-Trek, the Enterprise real-
ly was run by a crew. Each member of this crew manned
a terminal on the computer system, and depending on
how the game was initialized, each crew member played
a specific role. Thus, one terminal was run by the com-
mander of the ship, another was manned by the weapons
officer, a third was dedicated to navigational tasks, and
so on. A separate graphics display showed the various
sector maps and status tables of the game, while an added
element of feedback was provided by a colored light dis-
play and a voice synthesizer that intoned such messages
as "RED ALERT" or "SHIELDS UP."
All in all, the many dramatic sessions played on this
system were rated as some of the best examples of en-
vironmentally supported learning that took place during
the project. The word learning is used here with delibera-
tion. The rules for handling the various roles in N-Trek
104 January 1981 © BYTE Publications lnc
Circle 61 on inquiry card.
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Education Forum
Photo 2: The equipment currently available in the Solo/NET/works laboratory. The terminal at the lower left in Photo 2a is used for
the WAG display (as explained in the text). To its right is the IMSAI S-100 computer that emulates the unrooted-tree network and
performs the managerial WAG functions. Further to the right are the system console and bus-status monitor; the other micropro-
cessors operate as nodes in the network. Photo 2b shows MATSRCH designer Ivan Zatkovitch using an Apple II computer in a ver-
sion of the game that requires only one player.
were extremely complex, yet it was possible to bring in a
group of neophytes and have them playing well in very
short order. The most remarkable thing about this learn-
ing was that it took place with surprisingly little explana-
tion time; it happened mostly as a result of doing what-
ever was necessary to handle the task at hand. It was also
a form of learning that prompted students to develop new
strategies and theories. It was, to use a phrase we later
coined as being particularly appropriate, inventive learn-
ing.
The Generalization of N-Trek
The new Solo/NET/works project (which like its
predecessor is supported in part by the National Science
Foundation Development in Science Education program)
can be looked upon as an extension and generalization of
the N-Trek experience. The goal of the project is to
develop a prototype learning environment that will sup-
port a variety of multiprocess simulations.
Physically, the environment will consist of a room (or
several rooms) in which there is a variety of microcom-
puters interconnected via a loosely coupled network. The
phrase loosely coupled is used in two senses. Technically,
it means that the microcomputers in the network have in-
dependent (and very likely differently designed) system
buses, and that they do not share memory. Pedagogical-
ly, it is used to mean that each microcomputer node will
be running an independent program (ie: process) that
uses its own independent memory. The node processes
will be able to cooperate, but only in ways determined by
the program designers, and only via data communicated
over the network.
The reason we have kept the prefix Solo in the project
name is to emphasize that the student controlling a given
process (which may or may not have been designed by
that student) is in charge of that aspect of the overall
simulation. The sharing of data and the choice of which
processes are to be cooperative is to be a student-team
decision, and modifications of this decision will be
viewed as an integral part of the learning process. We
want the student activities to mirror the team efforts of
professional scientific and engineering projects, but with
strong emphasis on independent thought within a group
effort.
Educational Applications
The tasks we have set in the first phase of the project
(1980 thru 1982) are technical in nature. The first issue we
must address is that of finding simple ways to intercon-
nect low-cost hardware in a cooperative network setting.
For this reason, it is premature to talk about applications.
Of course, they will eventually be the most important
aspect of the project.
Our approach to applications in this first phase has
been to outline scenarios describing how the system
might be used, but to do most of our initial network
testing with simplified surrogate applications (an example
will soon follow). The purpose of the scenarios is to help
us verify the accuracy and workability of the various
system hardware and software decisions that must be
made right away, while helping point the way to the best
use of new technology sure to be available by 1982 and
beyond.
One example of a scenario we have found useful is
based on the use of the Solo/NET/works system to
model both realistic and futuristic air traffic-control
systems. In this application, some students will play the
role of pilots flying a variety of aircraft. Each student
will control a microcomputer at a node of the network.
The principal process running in the computer at one
node will be a program that simulates the flight
characteristics of a given (or imagined) aircraft. The
other microcomputer nodes will be manned by air-traffic
controllers. The principal process running at each of
these nodes will be one that interprets data returned from
aircraft transponders (a transponder is an "encoded"
transmitter located in an aircraft), along with data on the
position of ground-based navigational aids.
106 January 1981 © BYTE Publications Inc
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BYTE January 1981 107
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Education Forum
There will also be a distinguished node in the network
which we call the WAG (Weltanschauung, or "world
view," Generator). This will calculate all the data needed
to generate a graphic display of the total universe within
which these pilots and controllers function. Normally,
the total WAG display will be visible only to observers or
visitors who are not engaged in the simulation. However,
windows on this universe appropriate to the functions at
specific nodes will be available to these nodes. For exam-
ple, an air-traffic controller will be given a graphic
display of the aircraft in the specific sector he controls.
This corresponds to the way in which radar displays are
actually used today.
What will be learned by students working in such an
environment? Specific learning will be in the areas of
aerodynamics, navigation and geometry, piloting, and
air-traffic control (for those so inclined vocationally).
Also involved are large-system design, distributed com-
puting, data-base design, and, of course, the physics and
mathematics of Newtonian dynamics.
The Solo philosophy assumes that students will play an
active role in the design and modification of the programs
for the node processes. More importantly, we believe
that the participants who design, develop, debug, and use
such a system will learn to be inventive — to devise
strategies and procedures that transcend anything that
even the best teacher or text could hope to transmit.
The ultimate power of a multi-micro network is found
in the fact that all the processes are run on general-
purpose computers. This means that entirely new ap-
plications, and an entirely new set of challenges to be in-
ventive, are only as far away as the imaginations of the
users. We have found that visitors often suggest in-
genious examples of such applications and that these
represent a multitude of disciplines. Some of the other
scenarios that we are working on as a result of such
discussions are in the areas of corporate-business
management, computer-operating systems, economic
models, the colonization of space, and models of human
physiology that could be used in medical education.
Network-Architecture Considerations
The subject of computer networking is extensive, and a
substantial amount of literature detailing a variety of ap-
proaches has developed over the years. For our purposes,
with our constraint to work with low-cost, off-the-shelf
microcomputers, most of the options discussed in the
literature were not directly applicable. It also became
clear that, as with any new development, the promises of
what could be done tended to be ahead of the availability
of actual products. However, we spent some time think-
ing through the consequences of trying to apply the most
recent ideas about local-area networking to our applica-
tion, subject to the constraint that costs had to be
minuscule compared to those associated with the com-
mercial and scientific networks in use today.
We decided that even with this constraint, it would be
advantageous to work conceptually with the unrooted-
tree passive-bus configuration, considered one of the
most powerful local-network architectures. Another
name for this arrangement is the global multiple-access
Circle 63 on inquiry card. ^— ^
THEY INVENTED THE WHEEL . . .
During 1 978 a set of four business systems was developed
for sale in the CP/M environment under the name
"Peachtree Software". Since then,
this software has been used in over 3000
installations, and sold through more than — / ^F\
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however, there was a split among — ~ / fiL//
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with them for one year. We are now ready to market our
business software to you under the name of "Insoft Accountant"
WE GAVE IT A NEW TWIST
Thanks to the Z-80 Softcard® by Microsoft, this software is
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Apple II or Apple II Plus with 48K RAM, 2 drives,
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data files to get you up and rolling fast.
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This fully Integrated Business Software Package for S 3B5 includes:
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ORDERING INFORMATION — Fill out and mail
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Apple II. CP/M. Peachee Software and Microsoft are registered trademarks of Apple Computer Inc Digital Research Retail Sciences, he , and Microsoft Consumer Products. Inc . respectively
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Education Forum
bus. Recent applications of this architecture are the Xerox
Company's Ethernet, and the Ungermann-Bass Net/One
system.
Figure 1 gives a brief summary of some of the network
architectures in use today. Although the passive-bus con-
figuration appears to lack the complexity of the others, it
is in reality a very general arrangement. This is because
the bus (the heavy horizontal line) is assumed to be a
wideband communications medium (usually a coaxial
cable) to which any node can be connected by means of a
transceiver. The transceiver contains sophisticated cir-
cuitry that allows the nodes to contend for access to other
nodes without waiting for their turn in a polling scheme.
This circuitry also allows for flexible addressing schemes
that allow the access paths in the network to be con-
figured in any way desired. Logically, this configuration
is equivalent to a fully connected distributed system, with
no limitations or dependencies on which nodes are to act
as control centers.
Since it is not yet possible to buy low-cost bus hard-
ware such as transceivers off-the-shelf for use with the
popular microcomputers, we are simulating the passive
bus-architecture with an S-100 microcomputer. The other
node microcomputers in the network connect to standard
serial I/O (input/output) ports on the S-100 machine.
The idea is to have a program segment running in the
S-100 computer that makes these ports appear to be
"taps" onto a passive bus. Actually, all communications
from the nodes will be via RS-232C ports which are
available at a low cost. In the spirit of limiting costs even
further, we are experimenting with having the same S-100
computer also act as one of the nodes.
Hardware and Software
There are many ways to put together a system that acts
like a general microcomputer network. One approach
would be to use a single machine running a sophisticated
operating system like UNIX (a development of the Bell
System Laboratories), which allows the various users on
the system to set up "pipelines" with each other. Bill
Gates of Microsoft has indicated that they will soon have
such a system for use on the newer 16-bit microcom-
puters. This product will undoubtedly be worth in-
vestigating when it becomes available.
Two other products we considered were the Nestar
system and the Corvus Constellation system. The Nestar
system is designed specifically for Apple computers and
the Apple II bus. The Corvus system was not in use any-
where that we could visit. Although both these products
are ingenious developments, we felt that with the lack of
generality and experience with their use, it would not be
wise to acquire the Corvus and Nestar systems at this
time. This decision was further supported by our
equipment-budget limitations and our desire to test the
feasibility of using a variety of low-cost microcomputers
as network nodes. Once we have a better feel for the
capabilities of the various machines, we will not be hesi-
tant in choosing the models that perform the best for us.
It is pretty clear that trying to accommodate all the dif-
ferences found in the various brands of microcomputers
today can create lots of problems.
110 January 1981 © BYTE Publications Inc
Circle 64 on inquiry card.
Mass Storage any style
nobody does it better.
.^cs^
Presenting Konan's Disk and Tape Controller
Boards for your S-lOO system. Konan's Disk and
Tape Controller Boards allow you to dramatical-
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that's guaranteed reliable, yet economical.
Take your pick to suit your needs. There's the
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software compatible with Alpha-Micro's
AM-500*...Konan's new SDC-lOO error correcting
intelligent disk controller for the Shugart
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'Alpha Micro AM-500 is a trademark ol Alpha Micro Systems
SMC-lOO. HARDTAPE and KNX-500 are trademarks ot Konan Corporation.
Circle 65 on Inquiry card.
Better can't be found. For exciting, but depen-
dable hard disk and tape controller boards (and
superlative I/O boards) for your S-lOO computer,
contact the company that's IN CONTROL.
Call Konan's direct toll-free information line;
800-528-4563.
Or write: Department B, Konan Corporation, 1448
N. 27th Avenue, Phoenix, Arizona 85009.
TWX/TELEX 9109511552.
BYTE January 1981 111
Education Forum
BUS (UNROOTED TREE)
DISTRIBUTED, MINIMALLY CONNECTED (RING)
CENTRALIZED
DISTRIBUTED, FULLY CONNECTED
DECENTRALIZED
HIERARCHICAL (TREE)
Figure 1: Examples of network architecture. A network consists of nodes that are linked through communications channels. In these
diagrams, square boxes represent nodes that act as resources in the network, circles represent users of these resources, and diamonds
show devices or persons that act as intermediaries (buffers, terminals, displays, etc). The letters P and C indicate that the node is a
person or a computer; a blank node means that the nature of the node is not specified.
Fortunately, the lack of standardization is not as severe
a problem with microcomputer languages and operating
systems, and we had no misgivings about using Microsoft
BASIC running under CP/M in the S-100 computer. Both
products have proven to be sophisticated and reliable.
Being able to count on this kind of stability has been a big
plus. We may look into using the C or Pascal languages
later on, but the microcomputer versions of these are still
relatively new.
The simplest choice of system software for low-cost
computers like the Apple, Atari, and Radio Shack's
TRS-80 is to use whatever is supplied by the manufac-
turer. This can cause problems, however, and since it is
now possible to add the CP/M-Microsoft BASIC com-
bination to both the Apple and TRS-80, we may take this
route later on. For the time being, we are trying to work
with the system software supplied with each of these
machines, supplementing it where necessary with bus in-
terface programs written in machine language.
Surrogate Applications
By now it should be clear that putting together a
system of this type is a complex job, especially for a small
staff. Some of this complexity can be sorted out by
recognizing that we (and, later on, others who wish to
replicate the system) must wear three hats. The most im-
portant of these will eventually be that of the educator
who uses the system. The second will be that of the
application-program designer. The third is the one we are
wearing most of the time at present, namely that of a
multisystem designer. The job of a multisystem designer
has to come first since the others build on its products.
The problem is that any decisions at the system level can't
be made without experience at the application level.
At this time, our strategy for dealing with this dilemma
is to give consideration to a variety of educational ap-
plications, but to hold off on implementing them fully. A
considerable effort in software engineering will be needed
to implement the more advanced applications we have in
112 January 1981 © BYTE Publications Inc
Circle 66 on inquiry card.
First compare quality.
Then compare cost.
Morrow Designs' 10 megabyte
hard disk system: $3,695.
MORE MEMORY. LESS MONEY.
Compare Morrow Designs' DISCUS
M26'" hard disk systems
to any system available
for S-100 or Cromemco
machines. First, compare
features. Then, com-
pare cost per mega-
byte. The M26 works
out to under $200 a
megabyte. And the M10 is
about half the cost of com
peting systems.
COMPLETE SUBSYSTEMS.
Both the M10 (8"), and the M26
(14"), are delivered complete with
disk controller, cables, fan, power sup
ply, cabinet and CP/M* operating
system. It's your choice: 10 Mb 8"
at $3,695 or 26 Mb 14" at $4,995.
That's single unit. Quantity prices are
available.
BUILD TO FOUR DRIVES.
104 Megabytes with the M26. 40+
megabytes with the M10. Formatted.
Additional drives: M26: $4,495.
M10: $3,195. Quantity discounts
available.
S-100, CROMEMCO
AND NORTH STAR?
The M26 and M10 are sealed-media
hard disk drives. Both S-100 controllers
incorporate intelligence to super-
vise all data transfers through four I/O
ports (command, 2 status and data).
Transfers between drives and control-
lers are transparent to the CPU. The
controller can also generate interrupts
at the completion of each command
. . . materially increasing system through
put. Sectors are individually
write-protectable for multi-
use environments. North
Star or Cromemco?
Call Micro Mike's,
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for the software ♦ '
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Price: $299 (kit), $349 assembled
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MAKE HARD COMPARISONS.
You'll find that Morrow Designs' hard
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Or, write Morrow Designs. Need infor-
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Look to Morrow
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MORROW DESIGNS
*CP/M is a trademark ol Digital Research Corp.
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Education Forum
mind, and for these we feel that it is wisest to confine
ourselves to the highest level of the application design
process at present. The catch to this strategy is that it
doesn't get into the nitty-gritty detail that can have im-
portant repercussions on network -level design decisions.
To handle this obstacle, we are also working with the
complete design and testing of what we call surrogate ap-
plications. These are highly simplified but fairly accurate
mappings of what we believe will be the essential ingre-
dients of real applications.
The first surrogate application we have worked with is
a game called MATSRCH. It was designed by Ivan
Zatkovich as an undergraduate. He has since graduated
and moved on to bigger and better things as a computer
scientist. His application was designed to work with a
minimal system in which an S-100 computer provides the
network -bus function, while also handling several node
tasks.
The arrangement of components used in MATSRCH is
shown in figure 2 and photos 2a and 2b. The S-100 com-
puter consists of an IMSAI mainframe equipped with an
Ithaca Intersystems Z80 processor board and memory
boards, and a Morrow disk controller and I/O boards.
The computer runs Microsoft 5.1 BASIC under CP/M.
The nodes controlled by persons Pi, P2, P3, and so on,
are equipped with low-cost machines such as the Apple
II, the Atari 800, and the TRS-80. The processes in each
of these machines are written in the BASIC supplied with
the machine (usually a variant of Microsoft BASIC).
The idea of MATSRCH is to allow several players,
each with his own computer, to move a spaceship
through a world defined by a matrix-like coordinate
system. Players issue commands that move their ships,
ask for scans of the area in which they are located, and
rendezvous with other ships. The program running in the
S-100 computer performs three tasks: it manages the
communication of data between nodes (ie: it emulates the
network bus function), it keeps track of where everybody
is in the matrix world of the game (supplying this infor-
mation to the WAG display), and it displays bus-status
information on the system console. This last function is
not essential to the game, but it is a revealing way to keep
tabs on where the bottlenecks in communications occur.
The present version of this simplified net monitor
shows whether the S-100 program is doing network poll-
ing (and buffer management), interpreting data received
from the nodes, or handling the WAG display.
The programs in the spaceship nodes are quite simple
at present. They allow the players to issue commands
that control the motion of their ships, and ask for infor-
mation about the presence of other ships. The game limits
the range that a player may ask to scan. In effect, in-
dividual nodes are able to look into small windows on the
global space known to the WAG. Each node application
program is also able to call upon a suitable driver pro-
gram that can transmit or receive data from the bus. The
programs in the nodes are actually parallel processes that
cooperate in the MATSRCH game. The important point
to note is that these processes can be expanded to take ad-
vantage of all the power of the microcomputer in which
they reside. This is an important point; the local nodes
114 January 1981 © BYTE Publications Inc
Circle 67 on inquiry card.
Circle 68 on Inquiry card.
"When you sell to small
business, learn to speak
their language. COBOL- 80."
Ron Mayberry
May berry Systems, Inc., Belleville, Illinois
"It's amazing what a
few key phrases will do
for your sales record
to small businesses.
Words like "faster,"
"cheaper," and
Microsoft's "COBOL-80"
I should know. I'm in
the business of selling
complete computer sys-
tems to one of the most
demanding enterprises
around: pharmacies.
That means my pro-
grams have to solve
the complex problems
facing pharmacies today
—the deluge of paper-
work, regulations, and
the need for immediate
access to patient
information.
I've sold a lot of mini-
computer systems with
programs written in
DIBOL. Then I discover-
ed microcomputers,
and Microsoft's
COBOL-80. Together,
they're faster and less
expensive than my old
system, yet do all the
same things. And more.
Like what? Like
more flexibility and ver-
satility. I use practically
the whole range of
COBOL-80 features, to
speed inventory, billing,
labeling, pricing,
accounts receivable,
patient profiles and
doctor lists. And I'll be
using a lot of the same
features to write a pro-
gram for travel
agents too.
Believe me, we
checked them all, and
only COBOL-80 had all
the necessary LEVEL II
features, plus the new
CHAIN feature, pro-
gram segmentation
and formatted screen
ACCEPT/DISPLAY.
The CHAIN feature
impressed even a
veteran programmer
like me. With my menu-
driven systems, I have
total control over which
program will execute
next. And it was great to
find that COBOL-80's
ACCEPT/DISPLAY
statements give for-
matted screens that
look the same as my old
DIBOL screens. Yet
with fewer lines of code.
With 300 different
program modules, you
can be sure I appre-
ciate segmentation too.
In one case, I collapsed
seven DIBOL programs
into one segmented
COBOL-80 program.
Now I can organize my
system according to
program function rather
than memory size.
My compile times?
Incredible. Over 1,500
lines compile and link in
just five minutes.
I know what you're
thinking. 'Sounds great,
but I wouldn't want to be
in Mayberry 's shoes
when he translated all
those DIBOL programs
to COBOL-80.' Well,
surprise. Since most
Dl BOL features trans-
late into COBOL one-
for-one, we converted
the source code six
times faster than
originally scheduled.
So simply put, that's
how Mayberry Systems
Inc. learned for itself
that COBOL-80 is one
language that makes
a lot of sense to
small businesses.
In my opinion,
COBOL-80 is first-
class. And I thought
you should know about
it too."
COBOL-80 now sup-
ports Level II ANSI
SORT/MERGE state-
ments to interface with
Microsoft's new sort
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COBOL-80 with
documentation, $750.
Documentation purchased
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M/SORT, $125.
10800 NE Eighth, Suite 819
Bellevue, WA 98004
206-455-8080 Telex 328945
We set the standard.
Education Forum
S-100 MICROCOMPUTER RUNNING MICROSOFT BASIC UNDER CP/M
MATSRCH LOCAL PROCESSORS
Figure 2: The hardware and software arrangement for MATSRCH. This application uses an S-100 computer (indicated at the top of
the diagram) for a variety of functions: the segment labeled "BUS" is involved in emulating the unrooted-tree network shown in
figure 1. Each microprocessor node has a principal function (the task assigned to that node, indicated by a square) and a driver pro-
gram that handles communications (indicated by a diamond).
are not just terminals connected to a central processor.
As was noted earlier, all communications between
nodes are via RS-232C serial lines. Thus, even though our
work is primarily concerned with a local network, there
is still the capability of connecting several schools
together via telephone lines and modems. The potential
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of interscholastic simulation gaming between several
local high schools and colleges is intriguing, especially in
terms of the higher levels of supportive social en-
vironments that could result. ■
Acknowledgments; Further Information
The Solo/NET/works project derives many of its
ideas from its two predecessors, Project Solo and the
Soloworks Laboratory. All three projects were funded
in part by the Education Directorate of the National
Science Foundation. Examples of early curriculum
units from Project Solo were reprinted in Creative
Computing in 1979 and 1980. Articles describing some
of the activities of Soloworks appeared in BYTE in
December 1976, August 1977, March 1978, and May
1978. A description of the educational ideas that
underlie the Solo philosophy was given in the article
"Books As an Antidote to the CAI Blues" which ap-
peared in the Education Forum of BYTE in June 1980,
page 74.
Documentation of the Solo/NET/works project will
initially be in the form of working papers. These are
for internal use only, but revised versions will later be
submitted for publication in the Education Forum of
BYTE. If you'd like to be placed on a mailing list for a
notice of what has been published and where it ap-
peared, send your name and address to Margot
Critchfield, Department of Computer Science, Univer-
sity of Pittsburgh, Pittsburgh PA 15260. However,
please understand that it will be some time before a
complete list is available.
The material in this preliminary report is based in
part on working papers by faculty associate Dr Sig
Treu, and project staff members Margot Critchfield,
Bob Hoffman, and Blaise Liffick. The material on the
MATSRCH application was derived from a paper in
preparation by Ivan Zatkovich.
116 January 1981 © BYTE Publications Inc
Circle 69 on Inquiry card.
A PASCAL/M Demo Disk from Sordm.
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for microcomputer applications.
THE INCREDIBLE
$10 FREE OFFER"
OK, I can't pass up your Incredible $10 Free Offer.
Please send me the Items checked below:
□ PASCAL/M Demo Disk $ 10.00
□ PASCAL/M User's Reference Manual $ 10.00
□ Demo Disk and Reference Manual $ 20.00
I understand that I'll receive full credit for my Incredible $10 (or
$20) Free Offer if I order the full PASCAL/M package by July
31, 1981.
□ I can't stand it; I've got to have the full PASCAL/M package,
including Compiler, Object Library, P-Code Interpreter, Ref-
erence Manual and Demo Disk.
□ Z80* □ 8080/85* □ Z80/951 1*
*S/xKi)5>.-nCP/MornCDOS $175.00
□ 8088/86 (Requires CP/M 86) $250.00
□ Master Card □ VISA □ Ship UPS COD.
□ Check or money order enclosed
Card Number Exp. Date
Master Card Interbank Number
Signature
(for credit card purchase)
Total amount enclosed
PASCAL/M is a trademark of Sorcim
CP/M is a registered trademark
of Digital Research
Z80 is a trademark
of Zilog Corporation
(California residents add 6.5% sales tax; for overseas shipment, add $10.00;
for shipment to Canada or Mexico, add $5.00.)
SHIP TO:
ADDRESS:
CITY:_
STATE:
(No P.O. boxes, please)
.ZIP_
K
SORCIM
1333 Lawrence Expressway
Suite 418
Santa Clara, CA 95051
(408)248-5543
Circle 70 on Inquiry card.
BYTE January 1981 117
System Review
The HP-41C:
A Literate Calculator?
Brian P Hayes
Scientific American
415 Madison Ave
New York NY 10017
Calculator vs Computer
The computer and the programmable calculator seem
to be following paths of convergent evolution. As the one
is made smaller while the other gains in capability, the
line of demarcation between them becomes more and
more arbitrary. For now at least, the programmable
calculator remains a distinct and lesser species, but it
shares many of the attributes of the computer. Moreover,
the shared attributes are chiefly the ones that make the
computer an interesting machine. Both devices offer an
intimate acquaintance with the powers and pleasures of
algorithms. Both exhibit an enigmatic unpredictability:
the response of the machine to any given stimulus is
wholly deterministic, yet the behavior of a large program
Photo 1: Components of the Hewlett-Packard HP-41C
calculator system. Shown here are the calculator itself and three
peripheral devices: a magnetic-card reader, a wand for reading
printed bar codes, and a thermal dot-matrix printer. The
peripheral units plug into four ports at the top of the calculator,
which can also receive modules containing additional memory
or preceded applications programs. The HP-41C alone costs
about $300; a system including all three peripheral devices and
two memory or applications modules is about $1000. (Photo by
Ed Crabtree.)
can be full of surprises, often to the frustration of the pro-
grammer.
The HP-41C, which was introduced by the Hewlett-
Packard Company about a year ago, is among the pro-
grammable calculators that lie closest to the computer
borderline. It comes close enough for the jargon of com-
puters to be useful in describing it. At the Corvallis Divi-
sion of Hewlett-Packard, where the HP-41C is made,
they refer to the calculator itself as the "mainframe" and
to its accessory devices as the "peripherals." The
calculator comes equipped with four input/output (I/O)
ports, through which the various elements of the system
are interconnected. Because the peripherals do some data
processing internally, the system might even be said to
have "distributed intelligence."
When compared with a computer, most programmable
calculators have a rich instruction set, but they are defi-
cient in memory capacity and in facilities for communica-
tion with the user. A calculator comes with such
amenities as trigonometric, logarithmic, and statistical
functions built in; with a computer, even floating-point
arithmetic must usually be constructed out of software.
On the other hand, no calculator has the memory needed
to store large tables or other data structures. And it is the
communication problem that most seriously limits the
utility of the calculator. A display that can represent only
the 10 digits, a decimal point, and a minus sign does not
have much range of expression. Even for problems that
have entirely numerical results, such a display is not
always adequate, since without labeling of any kind it is
easy to become confused about what a number means.
The HP-41C
In the HP-41C, the instruction set is at least the equal
of that in any other calculator and the potential memory
space is large (although it can never be large enough).
The most conspicuous distinguishing features, however,
have to do with communications and "human factors "
(or, in other words, those things that aid in writing pro-
grams and in interpreting their results).
All three of the peripheral units now available serve to
get information into or out of the HP-41C; they are a
printer, a magnetic-card reader, and a wand for reading
bar codes. But perhaps the most significant innovation of
all is in the calculator itself: a liquid-crystal display that
can represent not only numerals but also the complete
uppercase alphabet and a few lowercase letters and other
118 January 1981 © BYTE Publications Inc
The first personal computer
fM- under $20tt
The Sinclair ZX80.
A complete computer-
only $199. 95 plus $5. 00 shipping.
Now, for just $199.95, you can get a
complete, powerful, full-function computer,
matching or surpassing other personal
computers costing several times more.
It's the Sinclair ZX80. The computer that
"Personal Computer World" gave 5 stars
for 'excellent value.'
The ZX80 cuts away computer jargon
and mystique. It takes you straight into
BASIC, the most common, easy-to-use
computer language.
Yqu simply take it out of the box, con-
nect it to your TV, and turn it on. And if
you want, you can use an ordinary cassette
recorder to store programs. With the man-
ual in your hand, you'll be running programs
in an hour. Within a week, you'll be writing
complex programs with confidence.
All for under $200.
Sophisticated design makes the
ZX80 easy to learn, easy to use.
We've packed the conventional computer
onto fewer, more powerful LSI chips—
including the Z80A microprocessor, the
faster version of the famous Z80. This
makes the ZX80 the world's first truly port-
able computer (6V2" x 8V2" x 1V2" and a mere
12 oz.). The ZX80 also features a touch
sensitive, wipe-clean keyboard and a
32-character by 24-line display.
Yet, with all this power, the ZX80 is easy
to use, even for beginners.
^e-nBASiCpm
Your course in computing.
The ZX80 comes complete with its own
128-page guide to computing. The manual
is perfect for both novice and expert. For
every chapter of theory, there's a chapter
of practice. So you learn by doing— not just
by reading. It makes learning easy, exciting
and enjoyable.
You'll also receive a catalog packed with
items that can make your ZX80 even more
useful. Including 27 program cassettes,
from games and home budgeting for just
$6. 95, to Sinclair's unique Computer Learning
Lab. And books, hardware options and
other accessories.
ZX80's advanced design features.
Sinclair's 4K integer BASIC has perfor-
mance features you'd expect only on much
larger and more expensive computers.
■ Unique 'one touch' entry. Key words
(RUN, PRINT, LIST, etc.) have their
own single-key entry to reduce typing
and save memory space.
■ Automatic
error detection.
A cursor identifies errors
immediately to prevent entering
programs with faults.
■ Powerful text editing facilities.
■ Also programmable in machine code.
■ Excellent string handling capability— up
to 26 string variables of any length.
■ Graphics, with 22 standard symbols.
■ Built-in random number generator for
games and simulations.
Sinclair's BASIC places no arbitrary re-
strictions on you— with many other flexible
features, such as variable names of any
length.
And the computer that can do so much
for you now will do even more in the fu-
ture. Options will include expansion of IK
user memory to 16K, a plug-in 8K floating-
point BASIC chip, applications software,
and other peripherals.
Order your ZX80 now!
The ZX80 is available only by mail from
Sinclair, a leading manufacturer of con-
sumer electronics worldwide.
To order by mail, use the coupon below.
But for fastest delivery, order by phone
and charge to your Master Charge or VISA.
The ZX80 is backed by a 30-day money-
back guarantee, a 90-day limited warranty
with a national service-by-mail facility, and
extended service contracts are available for
a minimal charge.
Price includes TV and cassette connectors,
AC adaptor, and 128-page manual.
All you need to use your ZX80 is a standard TV
(color or black and white). The ZX80 comes complete
with connectors that easily hook up to the antenna
terminals of your TV. Also included is a connector for
a portable cassette recorder, if you choose to store
programs. (You use an ordinary blank cassette.)
Hi
The ZX80 is a family learning aid. Children 10 and
above will quickly understand the principles of
computing— and have fun learning.
Master Charge or VISA orders call:
(203) 265-9171. We'll refund the cost of your call.
Information: General and technical— (617)
367-1988, 367-1909, 367-1898, 367-2555.
Phones open Monday-Friday from 8 AM to
8 PM EST.
inczlaii—
Sinclair Research Ltd., 475 Main St.,
P.O. Box 3027, Wallingford, CT 06492.
To: Sinclair Research Ltd., 475 Main St., P.O. Box 3027, Wallingford, CT 06492.
Please send me ZX80 personal computer(s) at $199. 95* each (US dollars), plus $5
shipping. (Your ZX80 may be tax deductible.)
I enclose a check/money order payable to Sinclair Research Ltd.
Name
for$_
Address-
City
.State_
.Zip.
Occupation:
Intended use of ZX80:
- Age: .
Have you ever used a computer? D Yes □ No.
Do you own another personal computer? □ Yes □ No.
"For Conn, deliveries, add sales tax.
symbols. The letterforms are crude but perfectly legible;
what they bring to the calculator is literacy, and it makes
all the difference in man-machine relations.
The architecture of the HP-41C is not fundamentally
different from that of its predecessors in the Hewlett-
Packard line. There is a four-level stack of registers where
pending operands are generally held; other registers are
identified by a 2- or 3-digit address. The internal memory
consists of 63 registers, but this number can be increased
by plugging memory modules into the ports. Each
module adds 64 registers, so that a full complement of
four modules yields a total capacity of 319 registers; with
all the ports occupied, however, no peripheral devices
can be connected.
The memory available can be divided in any way
desired between data storage and program storage. When
allocated to data memory, a register holds a single
floating-point number (10-digit mantissa and 2-digit ex-
ponent). Program capacity is more difficult to measure
because instructions have varying space requirements.
Without extra memory and with a reasonable allowance
for data storage, the maximum for an unassisted HP-41C
usually falls between 150 and 200 program lines. By add-
ing three modules and keeping the same data space, the
program capacity is expanded to about 1200 lines.
An additional wider register is dedicated to alphabetic
operations. Up to 24 characters can be accumulated in the
alpha register, although only 12 at a time fit in the liquid-
crystal display; the extra characters scroll in to the left,
marquee-style. The alphabetic capability is not a mere
frill. The extent to which it is called upon in the everyday
REMOTE I/O
Control AND monitor remote devices
Real time clock/calendar included
• An AC carrier communications I/O interface for the APPLE II*
computer. Output communications operate up to 256 BSR System
X-10* control modules. Input communications come from the X-10
command console, and temperature and security input modules,
soon to be available from Intelligent Control Systems, Inc.
• Software routines are provided to handle the AC I/O, to set,
read, and display the real time clock, and a background schedule
control program. 4 selectable interrupt rates allow machine
language programs to run simultaneously with other programs.
• Real time clock provides sec , min , hour , date , day of week , mo,
and year. Rechargable battery runs clock when APPLE is off.
• Trademark s-APPLE II : Apple Computer Inc. , System X-10 :BSR Ltd.
SEE YOUR APPLE DEALER FOR A DEMONSTRATION. .. $185 sugg. retail
Intelligent Control Systems, Inc.
POBOX 14571«MPLS,MN 55414* (612) 699-4342
operation of the calculator can be illustrated by consider-
ing one of the curious challenges of calculator design.
Mnemonic Functions
The problem is that most scientific calculators have
more instructions than they have keys; in the case of the
HP-41C, there are more than 130 instructions and only
thirty-five keys. A shift function doubles the number of
distinguishable key sequences, but that still leaves almost
half the instruction set without a home on the keyboard.
Rather than further increase the number of keys or the
number of shifted modes, Hewlett-Packard has adopted a
solution familiar in larger systems: all instructions,
whether or not they appear on the keyboard, can be ex-
ecuted by spelling out their mnemonic in the display.
Programs resident in memory and instructions associated
with peripheral devices can be executed in the same way.
Execution of a mnemonic label has the significant ad-
vantage of eliminating all dependence of the instruction
set on the layout of the keyboard. It also has certain
potential drawbacks that the designers of the HP-41C
have gone to some lengths to remedy, largely by ex-
ploiting the alphabetic display. For example, if the spell-
ing of a mnemonic is forgotten, a complete listing of the
instruction set can be called up by the CATALOG func-
tion.
Another objection is that repeatedly spelling out a
function can be tiresome on a keyboard smaller than the
human hand. This burden has been relieved by the
radical strategy of allowing all the keys to be redefined by
the user. Any instruction (with the exception of a few
program-editing pseudoinstructions) and any program
can be assigned to any key.
The fluid indeterminacy of the keyboard leads to a fur-
ther possible complaint: the user may lose track of what
function has been assigned to a particular key. Two
devices come to the aid of the forgetful. A keyboard
overlay slides into place to relabel the keys according to
the chosen assignments; if several programs require dif-
ferent key assignments, a separate overlay can be made
up for each one. The second aid is more elegant: the cur-
rent function of any key can be verified merely by press-
ing the key and holding it down a moment. The
mnemonic of the function appears in the display. If the
key is released, the function is executed; otherwise, the
word "null" appears and the command is canceled.
I A third aid to the use of the HP-41C keyboard is the
selection of the user/standard mode. The key redefini-
tions are valid only when the calculator is in the user
mode. To use a key that has been redefined for its
original function, the user has only to press the USER key
to toggle the calculator back to its standard mode. In the
standard mode, the HP-41C behaves as it would before
any keys were assigned, thus giving the user the best of
both worlds. . . . GW]
Further Features for the Programmer
The versatility of the liquid-crystal display is exploited
in several other ways to make the HP-41C friendly and
fool-resistant. A row of indicators below the main
display provides various indications of mode and status.
Error messages can be reasonably explicit: an attempt to
divide by elicits "data error," and a number greater
than 10" is flagged as "out of range." When a conditional
120 January 1981 © BYTE Publications Inc
Circle 71 on inquiry card.
Circle 72 on inquiry card.
NEW DISK SYSTEM
POLISHES APPLE
s-n
■
■
»hSM
I
I
... J •
Micro-Sci's new disk drive family
really makes your Apple shine.
Both the A-40 and A-70 offer
extra performance plus the ability
to read existing diskettes written
on Apple Disk II systems.
And a jumper selectable boot
prom for 13 and 16 sector interger
Basic or 8 sector Pascal comes
standard.
The Model A-40 actually costs
a lot less than Apple Disk II drives.
Yet it provides 40 tracks instead of
35, along with up to 20K increase
in capacity. Maybe an extra 20K isn't
anything to write home about, but
the speed sure is — 5 ms track to
track vs. Apple's 15 ms.
The Model A-70, on the other
hand, features twice the tracks and
capacity of the Apple Disk II, but
it costs only a few dollars more.
The secret of outstanding per-
formance and reliability is a state-
of-the-art design incorporating a
band positioner, instead of a plastic
fj-sa
cam, plus an improved media
centering system.
SPECIAL DISCOUNT.
One A-40 plus controller is priced
at only $495 and the second drive
is just $395. You can save
up to $200 per system over Apple II
drive prices.
And you can save even more if
you act now. Contact us today for
a special $50 introductory discount
on your Micro-Sci A-40 or A-70
system order.
MICRO-SCI
1405 E. CHAPMAN AVENUE • SUITE E • ORANGE, CALIFORNIA 92666
MICRO-SCI IS A DIVISION OF STANDUN CONTROLS, INC.
Apple and Apple II are registered trademarks of APPLE COMPUTERS INC., SAN JOSE, CALIFORNIA
714/997-9260
test, such as "X = 07", is executed from the keyboard,
the display answers the question "yes" or "no."
Alphabetic text can also have a valuable role within a
program. How it is employed is largely up to the pro-
grammer, but two obvious uses are prompting for inputs
and labeling outputs.
Even with the best of keyboard technologies, entering a
long program is inevitably tedious. A feature of the HP-
41C that helps in avoiding needless repetition of effort is
a continuous memory, which maintains all data and pro-
grams even when the calculator is turned off. Key
assignments, the settings of flags, and other status infor-
mation (such as the angular mode) are also preserved. A
program that is run frequently can be kept in the
calculator. Memory resources are finite, however, and on
occasion a program must be cleared to make room for
another and later reloaded. It is for such purposes that
the magnetic-card reader and the bar-code reader are in-
tended.
Using Cards
The magnetic-card reader, which occupies one port, is
a small unit that clips onto the top of the calculator and
can be left in place. The cards are the standard 1 by
7 cm magnetic strips (slightly smaller than a stick of
chewing gum) that are also employed by the HP-67 and
HP-97 and by some Texas Instruments calculators. They
are inserted in a slot at the side of the reader and pulled
through by a motor for retrieval on the other side. Each
card has two tracks and each track holds the contents of
16 registers, which can be either data or programs. A
olVo
cut vrco
kV* *<*
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122 January 1981 © BYTE Publications Inc
Circle 73 on inquiry card.
long program requires several cards, and a routine that
saves the state of the entire machine sometimes calls for a
whole deck of them.
Cues provided by the calculator make operations with
the cards almost mindless. When writing a program onto
cards, a message in the display indicates how many
tracks will be needed; when reading a program, the same
message gives the lowest-numbered track that has yet to
be read. The cards can be inserted in any sequence, and
the information is sorted out internally. A defective card
or an unsuccessful pass through the slot generates an ap-
propriate error message.
Cards can be both written and read at the command of
a running program. For example, a data card might be re-
quested during an initialization routine, and new values
might be written onto the card at the end of a calculation.
Or one of several possible subroutines might be appended
to a running program once the program had determined
which subroutine was needed. Unfortunately, all these
procedures still require human intervention for the actual
insertion of the card. Thus, the user must attend the
machine and feed it by spoonfuls on demand.
An amusing feature of the card reader is its ability to
create "private" program cards. When such a card is read
back into the calculator, the program appears in the
catalog and becomes available for execution, but it can-
not be examined, modified, or copied onto another card.
Any attempt to do so is blocked by the imperious
message "private." The security measures seem to be ef-
fective (although I have not worked seriously at
penetrating them); how often they will be needed is
another question. In the realm of very-small-scale
systems, the major worry is theft of hardware, not soft-
ware.
Software Compatibility
The introduction of a new model computer often raises
questions of software compatibility. In this case,
Hewlett-Packard has made the new machine compatible
with the old software by including a translator routine in
the card reader. Magnetic cards written on the HP-67 or
HP-97 can be entered into the HP-41C and, with no in-
tervention by the user, will be converted into HP-41C
programs. Thus, the machine has access to the large body
of software written for the earlier calculators, including
more than 3000 programs in a users' library administered
by Hewlett-Packard.
An incidental benefit is the addition of more than a
dozen instructions peculiar to the HP-67 and HP-97 that
become available on the HP-41C whenever the card
reader is plugged in, even though most of those instruc-
tions have nothing directly to do with card operations.
For example, there is a block-memory swap that comes in
handy occasionally.
Bar-Code Wand
One drawback of magnetic-card recording is the cost
of the medium: roughly fifty cents a card, plus the con-
siderable expense of the card reader itself. There is also
the delicacy of the iron-oxide surface, which necessitates
careful storage and the maintenance of duplicate copies
for backup. A second input device for the HP-41C, the
bar-code reader, relies on the most inexpensive of all
known storage media, ink on paper. The reader is a
Circle 74 on inquiry card. >
INTERFACE PRODUCTS FOR THE 80's
Multiport Serial Card
• Two or Four RS-232 serial ports with full handshaking.
• Independent baud rate generator for each port, with 16
software selectable rates from 50 to 19200 baud.
• Handshake lines include hardware start/stop control for
each port to interface with serial printers without additional
software.
• Each port can be configured as a "data set", for direct
connection to a terminal, or a "data terminal", for direct
connection to a modem.
• 8-level vectored interrupt controller handles receive and
transmit interrupt requests from each port.
• Interrupt controller may be slaved to our CPU Support Card
for fully vectored operation or it may be used in the "polled
mode" while retaining the interrupt masking and prioritiza-
tion features.
' Both of these cards are IEEE 696 (S- 1 00) compatible. They
have DIP switches for I/O port address and all options are
set with switches or easy-to-use pin shunts.
Price: 2-port, $250; 4-port, $350. Manual only, $3. Cables
$15 each in 14, 18, or 28 inch lengths.
CPU Support Card
• RS-232 serial port with full handshaking. Software-
controlled baud rate generator allows almost any conceiva-
ble data rate.
• Socket for 2716 or 2732 EPROM. The EPROM can drive
PHANTOM to allow a memory board to overlap, and it can
be disabled with an output command.
• 8-bit parallel input and output ports, each latched and with
full handshaking.
• Vectored interrupt controller. Provides 15 levels of vectored
interrupts, expandable to 64 through "slave" controllers on
other cards (such as our Multiport Serial). Includes
complete interrupts support for 8080, 8085, Z80, and 8086
microprocessors.
• Two general-purpose timer/counters, Each is 16 bits wide.
One may be combined with the time-of-day clock to count
days.
* Time-of-day clock. Time of day is kept in 24-hour format to
0.01 second. Power to run the clock may be provided from
an external source, such as a battery, to keep the clock
running when the computer is off. If time of day is not
needed, the clock may be used as two general-purpose 16-
bit timers.
Price: Card, $370. Manual only, $4. Cables, one 28" cable
provided. Additional cables, see above. 2716 EPROM
(single supply), $15 each or $13 in 10s.
From Seattle Computer, the System Design Experts
While each of these cards is a great individual
performer, together they form an unequalled interrupt
system. Up to seven Serial cards may have their on-
board interrupt controllers slaved to the master control-
ler on the Support Card for a maximum of 64 different
interrupt sources. Only SCP provides this kind of
expandability required for the multi-user systems of the
80's.
To help you tap the power of this system, each CPU
support card includes source code on diskette of a
complete, fully interrupt-driven I/O system for MP/M.
(MP/Mis a trademark of Digital Research Corporation.)
These products may be purchased from your local computer store.
Products are guaranteed one year — both parts and labor. Factory orders
shipped prepaid In USand Canada. Foreign purchases must be prepaid In
US funds. Also add $10 per board for overseas air shipment.
A
Seattle Computer Products, Inc.
1114 Industry Drive, Seattle, WA. 98188
(206) 575-1830
hand-held wand similar to a general-purpose one in-
troduced some months ago (the Hewlett-Packard
HEDS-3000), but it has an interface and a plug specifical-
ly adapted to the HP-41C.
With programs encoded and printed by Hewlett-
Packard, the wand works extremely well. A line of code
can be scanned in either direction, although multiple lines
must be read in sequence. The calculator display prompts
for the lowest-numbered line not yet read. Even more
helpful is audible confirmation. After each successful
pass, the calculator emits a high-pitched beep; a failure
results in a lower-pitched tone. The speed and orientation
of the wand are not critical, and with practice the success
rate becomes quite high.
The wand can also do a few things besides the
straightforward loading of programs. Individual instruc-
tions can be executed from a "paper keyboard" (which is
a table of bar codes, each of which is a single HP-41C in-
struction); data can be entered directly into designated
storage registers; subroutines can be appended and pro-
grams merged. One wand function, instead of translating
the scanned bar code into HP-41C operation codes,
displays the actual binary value represented by the bars.
Printed machine-readable code is an ideal medium for
the mass distribution of programs, and Hewlett-Packard
will reportedly make all its software for the HP-41C
available in this form. Programs from the users' library
will also be offered in bar code, presumably at a lower
price than programs on magnetic cards. For frequent
users of such prepared software, bar code seems to be the
medium of choice.
The situation is somewhat different, however, for
those whose main interest is in writing their own pro-
grams rather than in running other people's. The trouble
is that bar code, for now, remains largely a one-way
channel of communication.
It is possible to assemble by hand a bar-code represen-
tation of a program. The basic materials are adhesive
labels, each bearing the code for a single instruction or a
single numeric or alphabetic character. [The "paper
keyboard" can also be photocopied, with a program be-
ing created by cutting and pasting photocopied bar-code
keystrokes. . . . GW] A long program, however, would
require several hundred labels; moreover, they must be
scanned as a series of many short strokes. The ability to
reproduce the program by photocopying might
sometimes compensate for this inconvenience, although
the wand owner's manual warns that such copies may not
always give acceptable results. (Three copying machines I
tried all produced readable images, although the error
rate was somewhat higher than with originals.)
For those who have access to a computer system that
includes a daisy-wheel printer or a plotter, Hewlett-
Packard will supply programs in BASIC or FORTRAN
that will generate bar code in the HP-41C format. A far
more appealing method would be to produce the bar code
on the printer in the HP-41C system; if that could be
done, the wand might entirely displace the magnetic-card
reader. The HP-41C printer can readily be made to
generate patterns that superficially resemble bar codes. In
several weeks of experimenting, however, I have been
unable to persuade the wand to recognize those patterns
9f Micros aren't just for games anymore-
AARDVARK gets down to brass TAX. 99
AARDVARK SOFTWARE takes home com-
puter use one practical step further with "Per-
sonal Tax," a federal income tax program
designed specifically for home use.
"Personal Tax" was developed by CPA's
and computer professionals. It will calculate
Federal Forms 1040 and 4726, as well as sched-
ules A, B,G and TC. The program features mul-
tiple entries for a variety of inputs (e.g. wages,
dividends and charitable contributions). An in-
dexed instruction manual and easy-to-follow
input forms are included.
"Personal Tax" computes quickly and
accurately, then displays or prints the totals
automatically (using a standard printer inter-
face). You simply copy the totals onto your IRS
forms.
This spring, use your microcomputer to
simplify your taxes and file with confidence !
You won't have to spend half of your refund
either. The "Personal Tax" program is very
affordable at only $75.
"Personal Tax" will run on: Apple II ,TRS 80
Models I and II, and OSI. Additionally, under
CP/M, the program will run on Vector Graphics ,
North Star and Cromemco.
Minimum machine requirements:
48K and one disk drive.
Send check or money order, or, write us for
more information.
AARDVARK SOFTWARE INC
The Microcomputer People for Professionals
783NORTH WATER STRE El MILWAUKEE WISCONSIN 53202 414/289-9988
124 January 1981 © BYTE Publications Inc
Circle 75 on inquiry card.
THE PERFECT MARRIAGE
CHRISLIN 256KB MEMORY
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Free up critical and expensive backplane space. Saves you 3 dual slots.
Addressable in 4K increments up to 4 Megabytes.
On board parity generator checker totally DEC hardware and software compatible.
Single 5 volt power requirement.
Battery back-up capability. 256KB unit draws less than 300 ma at 5 volts in battery back-up
mode.
Tested and burned in. Full year warranty.
DON'T ASK WHY WE CHARGE SO LITTLE, ASK WHY THEY CHARGE SO MUCH.
c
Chrislin Industries, Inc.
Computer Products Division
31352 Via Colinas • Westlake Village, CA 91362 • 213-991-2254
Circle 76 on Inquiry card.
Multibus is a trademark of the Intel Corp LSI II is a trademaik ol Digital Equipment Corp
BYTE January 19SI 125
SORCERER"
SOFTWARE!
Unless otherwise noted, all programs are on cassette and
require only 8K of memory.
FORTH
new! Now Sorcerer owners can enjoy the convenience and speed of the fascinating FORTH
programming language. Based on FIGFORTH and written by James Albanese, this version
was designed especially for the Sorcerer and includes the capability to read and write data
(screens) to cassette tape and a complete on-screen editor. Requires at least 16K of RAM.
$49.95
new! GRAPHICS ANIMATION by Lee Anders. This package provides the BASIC program-
mer with a powerful set of commands for graphics and animation. The program is written in
machine language but is loaded together with your BASIC program and graphics definitions
with a CLOAD command. Any image from a character to a large graphic shape may be
plotted, moved, or erased with simple BASIC commands. Encounters of plotted character
sets with background characters are detected and background images are preserved. Con-
tains a medium resolution plotting routine. A keyboard routine detects key presses without
carnage returns. Includes a separate program for constructing images. $29.95
new! STARBASE HYPERION™ by Don Ursem. At last, a true strategic space game for the
Sorcerer! Defend a front-line Star Fortress against invasion forces of an alien empire. You
create, deploy, and command entire ship squadrons as well as ground defenses in this
complex tactical simulation of war in the far future. Written in BASIC and Z-80 code. Full
graphics and realtime combat status display. Includes full instructions and STARCOM battle
manual. Requires at least 16K of RAM. $17.95
new! HEAD-ON COLLISION'" by Lee Anders. You are driving clockwise and a computer-
controlled car is driving counter clockwise. The computer's car is trying to hit you head on,
but you can avoid a collision by changing lanes and adjusting your speed. At the same time
you try to drive over dots and diamonds to score points. Three levels of play, machine
language programming, and excellent graphics make this game challenging and exciting for
all. At least 16K of RAM is required. $14.95
new! LUNAR MISSION by Lee Anders. Land your spacecraft softly on the moon by
controlling your craft's three propulsion engines. Avoid lunar craters and use your limited
fuel sparingly. You can see both a profile view of the spacecraft coming down and a plan
view of the landing area. Land successfully and you get to view an animated walk on the
moon. Nine levels of play provide a stiff challenge to the most skillful astronaut. Requires at
least 16K of RAM. $14.95
new! HANGMAN/MASTERMIND by Charles Finch. Two traditional games are broughtto life
by Sorcerer graphics. HANGMAN has three different vocabulary levels for you to choose
Irom. I n MASTERMIND, the computer selects a four-character code and you have to uncover
it. These two games provide an enjoyable way for young people to develop their vocabulary
and their logical reasoning ability. Written in BASIC. $11.95
QS SMART TERMINAL by Bob Pierce. Convert your Sorcerer to a smart terminal. Used with a
modem, this program provides the capability for you to communicate efficiently and save
connect time with larger computers and other microcomputers. The program formats
incoming data from time-sharing systems such as The Source for the Sorcerer video.
Incoming data can be stored (downloaded) into a file in RAM. Files, including programs, may
be saved to or loaded from cassette, listed on the video, transmitted out through your
modem, or edited with an on-board text editor. Interfaces with BASIC and the Word
Processor Pac. $49.95
DPX*" (Development Pac Extension) by Don Ursem. Serious Z80 program developers will
find this utility program to be invaluable. Move the line pointer upward. Locate a word or
symbol. Change a character string wherever it occurs. Simple commands allow you to jump
directly from EDIT to MONITOR or DDT80 modes and automatically set up the I/O you want
for listings. Built-in serial driver. Stop and restart listings. Abort assembly with the ESC key.
Save backup files on tape at 1200 baud. Load and merge files from tape by file name.
Versions for 8K, 16K, 32K. and 48K Sorcerer all on one cassette. Requires the Sorcerer's
Development Pac. $29.95
Other utility programs:
PLOT by Vic Tolomei. High res and low res modes $14.95
SHAPE MAKER" by Don Ursem. An on-screen character maker $14.95
DEBUG by Bob Pierce. Debug machine language programs $14.95
SOFTWARE INTERNALS MANUAL by Vic Tolomei. A 64-page book $14.95
Other game programs:
MARTIAN INVADERS'" by James Albanese $14.95
NIKE II'" by Charles Finch and Bob Broffel $11.95
TANK TRAP by Don Ursem $11.95
MAGIC MAZE'" by Vic Tolomei $11.95
FASTGAMMON'" by Bob Christiansen $19.95
QUTILny SOFTWARE
6660 Reseda Blvd., Suite 105. Reseda. CA 91335
Telephone 24 hours, seven days a week: (213)344-6599
WHERE TO GET IT: Ask your nearest Sorcerer dealer to
programs. Or, if you prefer, you may order directly from
holders may telephone their orders and we will deduct $1
sate for phone charges. Or mail your order to the address a
sales tax. Shipping Charges: Within North America orders
shipping and handling. Outside North America the charge
is $5.00 — payable in U.S. currency.
•The name "SORCERER" has been Irademarked by Exidy. Inc
see Quality Software's Sorcerer
us. MasterCharge and Visa card-
from orders over $19 to compen-
bove. California residents add 6%
must include $1.50 for first class
for airmail shipping and handling
126 January 1981 © BYTE Publications Inc
Circle 77 on inquiry card.
reliably. The printer output itself, which is made up of
blue or purple characters, is not recognized at all by the
wand, and photocopies give erratic results.
Even if the problems of color, contrast, and resolution
could be solved, there would remain other impediments.
The bar pattern for most of the instruction codes exceeds
the capacity of the print buffer; what is more, with no
means of summoning up operation codes from program
memory, printing the bar-code representation of a pro-
gram would necessarily entail manual translation. With
the system in its present configuration, bar-code output
from the printer does not seem to be practical, although it
is tantalizingly close.
The mere possibility of obtaining
hard copy greatly enhances the
utility of the calculator . . .
The Printer
The printer is easily the most engaging component of
the HP-41C system. The mere possibility of obtaining
hard copy greatly enhances the utility of the calculator,
since it relieves the operator of the need to transcribe
results as they become available. The printer for the HP-
41C does more than that: it will reproduce anything that
appears in the display and much else besides.
The print mechanism is a thermal, dot-matrix one;
24-character lines are printed on rolls of heat-sensitive
paper about 6 cm wide. There is a standard set of 127
characters, including full uppercase and lowercase
alphabets, the ten numerals, a few Greek letters, and
miscellaneous other symbols and punctuation marks. All
characters can be printed in a standard 5 by 7 matrix or in
a double-width format. A few of the standard calculator
instructions trigger printing and, in addition, the printer
has its own repertoire of about twenty-five instructions.
Programs can be listed in their entirety, or a designated
number of lines can be printed out; in either case, the
listing shows the same mnemonics that appear in the
display. The path followed by the calculator through a
program being executed can be traced, providing a record
of all instructions and operands; this is a useful facility
when the program does not function as expected. The
contents of the operand stack can be printed out with a
single command; so can the contents of all allocated
memory registers, or of a defined block of registers. In
addition, assignments of nonstandard functions to the
keyboard and the status of all flags can be listed. All of
these functions can be executed manually or within a pro-
gram.
The most commonly invoked print functions are those
that print the contents of the X register (roughly
equivalent to an accumulator), the alpha register, or a
print buffer. The variations offered by these instructions
allow the output of a program to take almost any format
within the physical capabilities of the printer. The main
limitations are the time and space the programmer wishes
to dedicate to format commands. It is easy to list a series
of variable names, each followed by a colon or an equals
sign and a value. Tabulating two or three columns of
numbers so they line up vertically on their decimal points
Circle 78 on inquiry card. ■■■►
The MODEL 800 MST is certainly pleasing to look at, but its true beauty lies beneath the surface. A glimpse at its
features reveals why it is rapidly becoming the most sought after printer in the world . . .
Four standard interfaces:
RS-232(15 baud rates)
Centronics compatible parallel
IEEE-488
20ma current loop
Six line densities: 64, 72, 80, 96, 120, 132
100 CPS at all six densities
Unidirectional or bidirectional printing
Sixteen horizontal and ten vertical tabs
Elongated characters in all six densities
1920 character buffer
Uses either perforated or roll paper
Fully adjustable tractors to 9V2"
Auto self-test
• Up to 10 character fonts
Standard 96 character ASCII
User defined character font
Provision for up to eight additional fonts
• Dot resolution graphics in six densities
• Variable line spacing control from to 64 dots in
half-dot increments
• Auto form-feed for any form length at any line
spacing
• Heavy-duty all aluminum chassis
• 1 lOvac or 220vac, 50/60Hz.
• 100 million character printhead
• Measures only 15" wide, 3" high, and 11" deep
• Weighs only 15 lbs.
but maybe its most attractive feature is the price $699.00.
baxe_ inc.
W
P.O.
y —
BOX 3548 FULL., CAL. 92634 / C7ia) 992-4344
demands a somewhat larger investment of program
memory and execution time.
The dot-matrix print head is a single vertical row of
print elements that sweeps across the paper forming
characters as a series of columns (see table la). A special
set of printer instructions brings this process under pro-
gram control so that nonstandard characters can be
created. Indeed, the printer reproduces any pattern that
can be defined by a matrix 7 dots high and no more than
40 dots wide. If the pattern fits in a 7 by 7 box, it can be
treated as a special character, stored in a register, and
called up as needed. In principle, a complete font could
be built up in this way, although its usefulness might be
somewhat impaired by the limited capacity of the print
buffer: only 6 special characters per line can be printed. A
more practical application is the creation of schematic
symbols and markers, such as playing-card suits, chess
pieces, or the phases of the moon (see table lb).
Another capability of the printer is the plotting of
graphs for any function that can be expressed in the form
y = f(x). The graph is drawn under the direction of a
(a)
(b)
STANDARD CHARACTERS
SPECIAL CHARACTERS
I JZ
x g
* *^
ci o:
P
r r
i i-
A A
d a a
»T
♦ +
\ I-.
L' JU
■ ■ ■
/ V
f T
1 .j.
e e
= llll ■». ?s
C Q
'— '
fl fi
i A
.-■.•-•■yz-'yz-':---j-yz-''S.
M f=l
o d
o 6
Z-i m -Z m -l--Z<-ZK-'Z-^-Z-^--l
u u
E ft
fi 6ft
j^$35?SS5S$i
* #
I £
i &
?SS4SS5ftSSSii
i ;
v 3s
l &
§ #
( £
1 1 1 1 1 1
♦ ¥ ♦ ♦
) ;■
* *
+ +
.■ .■
V -x $ <?
- -
, .
/ ..-'
8 9
sZ-^r
1 1
?. £
3 3
4 4
-W
5 5
6 6
7 7
8 8
< W HI" H*
9 9
i j
< <
- =
\ --..
? '?
g fa
a n
B B
C C
n n
E E
F F
G G
H H
I I
J J
K K
L L
r) M
H N
P P
Q Q
R R
"^ ^
T T
U U
ti *■ i 1
V, W
- X
Y ¥
7 ~7
[ C
\ %
] ]
t t
_
T T
a a
b b
c o
d d
8 ■='
f f
9 "3
ii h
i i
j J
k k
i 1
n fi
n n
O
p p
i '3.
r r
i S
t t
U u
V •-,'
U 1.0
s X
7 V
2 2
if TV
1 1
■» -j-
I s
r I-
Table 1:
Character set as printed by the HP-41C printer. The
standard character set, shown in table la, contains 127 let-
ters, numbers
and
other symbols. About sixty of them, in-
eluding
the fu
11 uppercase alphabet,
can also be represented
in a somewhat different form in the
display of the HP-41C
itself. Each character can be printed
in a standard 5 by 7 dot
matrix or in a
double-width format. Special characters (table
lb) can
also be created by specifying the pattern of dots in
each column <
->f the character.
program called PRPLOT (print plot), which is committed
to read-only memory in the printer. When PRPLOT is ex-
ecuted (see listing 1), it first asks the user to supply cer-
tain information that determines the form of the
graph, such as the range of x and y. It then calls on a
named program, also supplied by the user, that for each
given value of x must return a value f(x). The resulting
graphs cannot compare to the product of an x,y plotter,
but they can be run off quickly and are adequate for
gauging the basic form and range of a function. PRPLOT
can also be executed from within a program without the
prompting for input values, and various parts of it can be
called independently.
Programming with Labels
An organizing principle of programs for the HP-41C is
that all references and transfers of control are made by
means of labels. The name given to a program constitutes
a global label, one that can be accessed from any point in
program memory. By invoking the name, a program can
be called as a subroutine and can even call itself, although
there are limits to such recursion.
Labels within programs are generally local, so that the
same labels can be repeated in different programs without
interference. Subroutine calls and branches can be made
only to a label; there is no absolute addressing by line
number. As a result, all programs and procedures within
programs can be relocated at will. Lines can also be freely
inserted or deleted without adjusting references
elsewhere.
Instructions that require an address or a numerical
argument can be given it either directly or indirectly. The
addressing modes are uniform for all memory operations,
subroutine calls, branching, loop control, the setting,
clearing, and testing of flags, and even such functions as
setting the display format and determining the pitch of
the beeper. A subroutine is called by the XEQ (execute)
function, which must be followed by a local label or the
name of a program.
If the instruction is an indirect one (XEQ IND), the
2-digit number that follows is interpreted as the register
where the subroutine name or label will be found. Any
register, including those of the stack, can hold the in-
direct address. Subroutines can be nested six levels deep
before the return address of the highest-level routine is
lost.
Conditional tests of numerical data include various
combinations of "less than," "greater than," "equal to,"
and "not equal to"; alphabetic strings can also be com-
pared, but only for equivalence. All the tests have the
same format, in which a false result causes the instruction
following the test to be skipped. Tests of flags (set or
clear) employ the same scheme. The complement of fifty-
six flags seems particularly generous. Eleven flags are
completely unencumbered for use in programs; the rest
control the status of the HP-41C and its peripherals,
thereby affording the calculator a valuable amount of
self-knowledge.
Loops
The control of loops in HP-41C programs is facilitated
by two instructions that store all the needed information
in a single register. The instructions, ISG (increment, skip
if greater) and DSE (decrement, skip if equal), refer
128 January 1981 © BYTE Publications Inc
Circle 79 on inquiry card.
STOP PLAYING GAMES
HH3lililVJillii:ilKi7
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into a Powerful Business Tool.
In business, professional offices, and schools through-
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bring mass storage, increased speed, and multi-user
capability to a variety of microcomputers. Current applica-
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records, mailing lists, inventories, word processing, insur-
ance, mathematics and science, and other large and
complex files.
Corvus proven Winchester disk technology provides
10 to 80 million bytes of capacity, fully compatible with
your current operating system. This is up to 500 times the ,
capacity of a floppy disk.
The Corvus CONSTELLATION links up to 64 com-
puters in a state-of-the-art multi-processor network. It
provides shared mass storage, pipes for inter-computer
communication, and system spooling for sharing of
peripherals such as printers. Performance far exceeds
that of larger and more expensive networks.
Backup data protection and archival storage are pro-
vided by the Corvus MIRROR (Patent Pending), a low-
cost backup using standard video cassette recorders.
Contact your local Corvus dealer for the full story
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r CORVUS SYSTEMS
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directly or indirectly to a register holding a number of the
form nnnnn.tttcc. Here nnnnn is the number to be tested,
ttt is the value against which it is tested, and cc is the
amount by which nnnnn is incremented, or decremented.
The compacted form is a convenience, although I find it
odd that the incremented number has a range of up to
99,999, whereas a jump must take place whenever it ex-
ceeds 999.
Other Programming Features
The HP-41C cannot realistically be said to support
structured programming, not as I understand the term.
The rule that all procedures should have a single entry
point and a single exit, which is one of the precepts of
structured programming, cannot be observed without ex-
treme awkwardness. On the other hand, the program-
control structures of the HP-41C strongly encourage the
composition of modular programs, where each procedure
is a self-contained unit, small enough to be fully
understood and capable of being tested independently. In
a program longer than a few hundred lines, some such
technique for imposing order is obligatory.
In the end, the capabilities of the HP-41C can be ex-
hibited best by real programs and their output. A few
short utility routines and a longer program, called
CHART, are given in listings 2 and 3. CHART, which in-
cidentally shows off to good advantage the versatility of
the printer, produces a bar graph, a form of display that
is more appropriate for some kinds of data than the line
graphs of PRPLOT.
At last— the
Typewriter Interface!
Turn your electric typewriter into a low cost, high
quality hard copy printer. 1 Year Warranty
Dynatyper— the patented* RDI— I /O Pak is fast becoming the industry
standard for typewriter output. Why? Because:
1. It takes 2 minutes to initially install and 5 seconds to remove or
replace.
2. You do nor have to modify your typewriter. All factory warranties
and maintenance agreements on your typewriter will be honored.
3. You can use it with all powered carriage return typewriters that
have U.S. keyboard. Our Model I works with all non Selectrics and
our Model II works with Selectrics. Conversion between models
takes 2 minutes and the kit (26 plungers) is available for a nominal
charge.
4. You don't have to lug around a bulky printer when you travel. If
there is a typewriter at your destination, you can install the light
(3 lbs.) I/O Pak in just 2 minutes.
5. Same interface for TRS-80, Apple and GPIB. Centronics and Pet
compatible interfaces are available in third quarter 1980. Electric
pencil available.
6. Delivery: Stock to two weeks. Price: $499. for the complete system,
FOB Rochester, Domestic.
Over 1000 in operation today. VISA and MasterCard accepted. Call
Ken Yanicky at 716-385-4336.
•Polenl Pending
3100 Monroe Avenue, Rochester, New York 14618
incorporated
The main program in CHART (listing 2), which is con-
fined to the first 20 lines, is little more than a list of XEQ
statements. It first prompts the user for needed informa-
tion, then does some preliminary calculations and prints
a header that will identify the graph. An external pro-
gram (see listing 4) is then called once for each bar; it is
expected to return a value defining the length of the bar
and a label of not more than 4 characters.
It is worth noting that the actual calculation of the bar
length is a trivial operation. The bulk of the program is
taken up with input and output routines, which are in-
tended to minimize the burden on the user's memory and
faculties of interpretation. A bar graph generated by the
CHART program is shown for data on the distribution of
digits obtained from the RDM LN pseudorandom-
number generator; see listing 5.
Next Generations
What more can one ask for in a programmable
calculator? Quite a lot; there is much to look forward to
in the next generation. More memory is always near the
top of such a wish list. One way of supplying it, which
might be compatible with the present mainframe, would
be in a double-density memory module. The entire ad-
dress space could then be utilized without filling all the
ports.
The very existence of ports inspires thoughts of other
Text continued on page 136
Listing 1: Graph of the function (sin x)/x was drawn by
PRPLOT, a program that resides in read-only memory in the
HP-41C printer. The function itself is defined by a separate pro-
gram (at bottom), which evaluates the expression each time it is
supplied with a value of x and called PRPLOT.
PLOT OF SIN/X
■
{ <UHITS= 1.) i
1
1 <0HIT3= E-2.> •>
-8.58 2.8E
8. 88
|_ 1 _
368
z
331
z
382
z
274
I
245
*
21b
I
137
•
158
X
138
I
181
I
-72
I
-43
■
-14
»
14
X
43
I
72
I
181
I
138
z
158
z
187
«
216
•
245
2
274
382
X
331
I
368
8I*LBL "SIN/
82 RCL X
83 SIH
84 XOY
85 /
86 END
130 January 1981 © BYTE Publications Inc
Circle 80 on inquiry card.
computer
products, inc.
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LEEDEX 100-80, 80x24 B&W $165.00
SANYO VM4509, 9" B&W $175.00
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or
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Circle 81 on inquiry card.
BYTE January 1981 131
Listing 2: A bar-graph program. CHART, the HP-41C program for generating bar graphs, is written as a series of modules. Thefirst
of these prompts the user to supply certain initial information that will determine the form of the graph. An alternative entry point,
CHARTP, is intended for occasions when the bar-graph routine is called from another program; this entry point bypasses the
prompting. For each bar drawn, CHART calls on a user-supplied program, which must return two items, the value to be plotted in
the X register and a label for the bar no more than 4 characters long in the alpha register. The bar is actually formed in subroutine 08
out of a standard character and additional print columns for fine adjustment of the length.
8WLBL "CHART"
62»LBL .5
03 XEQ 08
84»LBL -CHflRTP-
65 XEQ 81
66 XEQ 82
07 XEQ -BAR"
88»LBL A
89 XEQ 83
10 XEQ 84
11 XEQ 85
12»LBL 38
13 XEQ 67
14 RCL 13
15 INT
16 XEQ 1,'IB 11
17 XEQ 83
18 I3G 13
19 GTO 38
20 XEQ 67
21 GTO 50
22»LBL 80
23 CF 23
24 -PGH NAME?"
25 RON
26 PROMPT
27 FS? 23
23 A3T0 11
29 flOFF
30 CF 22
31 "NO. OF BARS?"
32 PROMPT
33 FS?C 22
34 STO 12
35 "Y KIN?"
36 PROMPT
37 FS?C 22
33 STO 13
39 "V MAX?"
46 PROMPT
41 FS?C 22
42 STO -14
43 -AXIS?"
44 PROMPT
45 FS? 22
46 STO 15
47 RTN
48»L8L 61
49 RCL 12
58 1
51 -
52 1 E3
53 /
54 STO 18
55 137
56 RCL 14
57 RCL 13
53 -
59 /
66 "STO
Initialization; can
be executed from
the keyboard by
pressing "A."
Main calculation and
printing of bars. Calls
a user program whose
name is stored in
register 11.
Subroutine that
prompts for inputs.
In each case the
prompting message
appears in the
display but is not
printed. If no value
is input following the
prompt, the program
assumes the value
supplied on the previous
run is still valid.
16
Set up register
for looped calls
to user program.
Calculate coefficient
relating /-axis
scale to graph width
of 137 columns.
61 RCL 15
62 XEQ 18
63 STO 17
64 5
65 XOY
66 X<=Y?
67 ST- 17
63 132
69 XOY
76 X>Y?
71 ST- 17
72 RTN
73»LBL 82
74 ODV
75 All"
76 "F"
77 ACA
73 SF 13
79 "LOT OF
86 ACA
81 CF 13
82 SF 12
S3 RCL 11
84 ACX
85 CF 12
36 PREUF
87 RTN
88+LBL 83
39 SF 12
98
91
ACA
92 7
93 ACCHR
94 29
95 SKPCOL
96 T
97 ACA
93 125
99 ACCHR
186 CF 12
161 PRBUF
162 RTN
103«LBL 04
104 RCL 13
165 ACX
166 XEQ 11
167 STO 16
188 RCL 14
169 XEQ 11
118 ST+ 18
111.144
112 RCL 16
113 -
114 SKPCOL
115 RCL 14
116 ACX
Calculate absolute
position of axis;
if beyond the range
of the graph, axis
is suppressed.
Print identifying
header:
"Plot of 'PGM NAME'
Print labels
for X and Y
Labels extrema
of Y axis.
117 ADV
118 RTN
119»L8L 85
128
121 STO 16
122 RCL 17
123 X=6?
124 RTN
125 119
126 ACCOL
127 RUN
123 RCL 15
129 XEQ 1!
130 ST+ 16
131 2
132 /
pi -
Labels axis
134 5
135 X>Y?
136 GTO 52
within graph,
if it has not
been suppressed
137 RUN
133 132
139 RCL 18
149 -
141 X<Y?
142 GTO 52
143 RUN
I44+LBL 52
145 I NT
146 SKPCOL
147 ST+ 18
143 RCL 15
149 ACX
158 XEQ 12
151 RTN
152*LBL 87
153 119
154 ACCOL
155
156 STO 18
157 XEQ 17
158 XEQ 12
159 RTN
166«LBL 88
161 ACA
162 3
163 SKPCOL
164-RJJN
165 XEQ 18
166 X<=8?
167 GTO 07
168 127
169 ACCOL
178 RUN
171 136
Accumulates markers
for the extrema points
and the axis in spaces
between bars.
Master subroutine
for accumulating and
printing a bar. Checks
if the length is zero;
if so, executes LBL 07.
Checks if the length is
Listing 2 continued on page 134
132 January 1981 © BYTE Publications Inc
SuperSoft's
Gallery of CP/M MasJcrworks
SUPER-M-LIST: A complete, easy to use mailing list program
package. Allows tor two names, two addresses, city, state, zip and
a three digit code field for added flexibility. Super-M-List can sort
on any field and produce mailing labels direct to printer or disk file
for later printing or use by other programs. Super-M-List is the
perfect companion to TFS. Handles 1981 Zip Codes!
Requires: 48K CP/M
Supplied with complete user manual: $75.00 manual alone: $10.00
TFS-Text Formatting Systtm: An extremely powerful formatter.
More than 50 commands. Supports all major features including:
• left & right margin justification • user defined macros
• dynamic insertion from disk file • underlining and backspace
TFS lets you make multiple copies of any text. For example: Per-
sonalized form letters complete with name, address & other inser-
tions from a disk file. Text is not limited to the size of RAM making
TFS perfect for reports or any big job. Text is entered using CP/M
standard editor or most any CP/M compatible editor.
Requires: 24K CP/M
Supplied with extensive user manual: $85.00 manual alone: $20.00
Source to TFS in 8080 assembler (can be assembled using stan-
dard CP/M assembler) plus user manual: $250.00.
TEXT PROCESSING
ff
tSL
DIAGNOSTICS I: Easily the most comprehensive set of CP/M compatible
system check-out programs ever assembled.
Tests:
• Memory • CPU (8080/8085/Z80) • Terminal • Disk • Printer
To our knowledge the CPU test is the first of its kind anywhere. Diagnostics
I can help you find problems before they become serious. A good set of
diagnostic routines are a must in any program library. Minimal re-
quirements: 32K CP/M. Supplied with complete user manual: $75.00 Manual
alone: $15.00
DIAGNOSTICS II: Includes all of Diagnostics I, plus:
• Every test is "submit"-able
• A complete Spinwriter/Diablo/Qume test has been added
(Serial Interface only)
• Output may be logged to disk
• Expanded memory test
• Expanded terminal test
• Expanded disk test
Diagnostics II provides the next level in system maintenance.
Requires: 32K CP/M
Price: $100.00 Manual only: $15.00
-I-iT* * * 1 .A.*. *.^.^.4. *******
'TINY' PASCAL II: We still call it 'Tiny' but it's bigger and better than everl This Is
the famous Chung-Yuen 'Tiny' Pascal with more features added. Features Include:
• recursive procedures/functions • integer arithmetic ■ CASE
• FOR (loop) • sequential disk I/O • 1 dimensional arrays
• IF...THEN...ELSE • WHILE • PEAK & POKE
• READ & WRITE • REPEAT.. .UNTIL • more
'Tiny' Pascal Is fast. Programs execute up to ten times taster than similar BASIC
programs. SOURCE TOO! We still distribute source, in 'Tiny' Pascal, on each
discette sold. You can even recompile the compiler, add features or just gain in-
sight Into compiler construction.
Requires: 36K CP/M. Supplied with complete user manual and source on discette:
$85.00. Manual alone: $10.00
STACKWORK'S FORTH: A full, extended Forth Interpreter/compiler produces
COMPACT, ROMABLE code. As fast as compiled FORTRAN, as easy to use as in-
teractive BASIC.
SELF COMPILING: Includes every line of source code necessary to recompile
itself.
EXTENSIBLE: Add functions at will.
Z80 or 8080 ASSEMBLER included.
Single license, OEM licensing available.
Please specify CPU type: Z80 or 8080
Supplied with extensive user manual and tutorial: $175.00
Documentation alone: $25.00
SSS FORTRAN: The SSS FORTRAN compiler is fast, efficient, and complete
(full 1966 ANSI standard with extensions). The RATFOR compiler compiles into
FORTRAN allowing the user to write structured code while retaining the
benefits of FORTRAN. The FORTRAN supports many advanced leatures not
found in less complete implementations, including: complex arithmetic,
character variables, and functions. Complete sequencial and random disk I/O
are supported. SSS FORTRAN will compile up to 600 lines per minute! Recur-
sive subroutines with static variables are supported. ROMable ".COM" files
may be generated. SSS RATFOR allows the use of contemporary loop control
and structured programming techniques. SSS RATFOR is similar to FORTRAN
11 in that it supports such things as:
• REPEAT.. .UNTIL • WHILE • IF. ..THEN. ..ELSE
SSS RATFOR is supplied with source code in FORTRAN and RATFOR.
System Requirements & Prices:
SSS FORTRAN requires a 32K CP/M system.
SSS FORTRAN with RATFOR: $325.00
SS FORTRAN alone: $250.00
RATFOR alone: $100.00
(Sold only with valid SSS FORTRAN license)
^"|" | ■■^-^"|"1 PROGRAMMING LANGUAGES |f**f "♦**♦'* <^y*C
SYSTEM MAINTENANCE
jtfSwSfe
325?
UTILITIES I: A collection of programs that you will find useful and
maybe even necessary in your daily work (we did!).
Includes:
GREP: Searches files for a specified string
SORT: In core sort of variable length records
CMP: Compare two files for equality
PRINT: Formatted listings to printer
PG: Lists files to CRT a page at a time
. . , plus more . . .
Requires: 24K CP/M
Supplied with manual on discette: $60.00
UTILITIES II: Many new programs not available elsewhere. Includes thi
"file" utilities:
DIFF. Source comparitor
PR: Powerful multicolumn output formatter
CAT: Concatenate files
RPL: Substitute strings in files
. . . plus more . . .
Requires: 24K CP/M $60.00
Supplied with manual on discette
UTILITIES
TERM: A complete intercommunications package for linking your com-
puter to other computers, Link either to other CP/M computers or to large
timesharing systems. TERM is comparable to other systems but costs
less, delivers more and source is provided on discette! With TERM you
can send and receive ASCII and Hex files (COM too, with included conver-
tion program) with any other real time communication between users on
separate systems as well as acting as timesharing terminal.
• Engage/disengage printer • error checking and auto retry
• terminal mode for timesharing between systems
• conversational mode • send files • receive files
Requires: 32K CP/M
Supplied with user manual and 8080 source code: $150,00
Manual alone: $15.00
INTERCOMPUTER COMMUNICATIONS?
ta
".'.'• "''"■■■ ' ■■:•'■■ .!;*€? -'.' ."' ■ ,j/
ANALIZA: An amazingly accurate
simulation of a session with a
psychiatrist. Better than the famous
r v
■ :: .
"ELIZA" program. Enlightening as
.::
■T :
well as fun. An excellent example of
Artificial Intelligence.
Requires: 48K CP/M. CBASIC2
M
P
Cost: $35,00
:':':
;i::ii;;;;;i::.j entertainment }■••::!;;;;;;•::
s
H<
'..'' ..,.'■' 'J <■ .... : -- ■'■'. '...' '■:'- - '.'. ■'■
ft
CI. 1
Z8000CROSS ASSEMBLER: Supports
full Z8000 syntax, segmented and
unsegmented mode, full 32- b 1 1
.-.
V.
arithmetic, hex output, listing output,
: : :
'■•/
"downloader".
v.
Requires: 56K CP/M $500.00
1 year maintenance $300.00
'._:_;'
:' i'i
1
manual alone $ 50.00
k
Ii;S""'ii!:R:!ii| zaoootoo! |::i"i::> :; '":i::ir
I ti 'L- ,1 -i — -±^ a-
ENCODE/DECODE: A complete software security system for CP/M.
Encode/Decode is a sophisticated coding program package which trans-
forms data stored on disk into coded text which is completely unrecog-
nizable. Encode/Decode supports multiple security levels and passwords.
A user defined combination (One billion possible) is used to code and
decode a file. Uses are unlimited. Below are a tew examples:
• databases • payroll files • programs • tax records
Encode/Decode is available in two versions:
Encode/Decode I provides a level of security suitable tor normal use.
Encode/Decode II provides enhanced security for the most demanding
needs.
Encode/Decode I: $50.00 Encode/Decode 11:5100.00 manual alone: $15.00
^ SOFTWARE SECURITY ^
On line "Help" system provided with every program package.
SuperSoft
First in Software Technology
Circle 82 on Inquiry card.
CP/M Formats: 8" soft sectored, 5" Northstar, 5" Micropo-
lis Mod II, Vector MZ, Superbrain DD/QD
All Orders and General Information:
SUPERSOFT ASSOCIATES
P.O. BOX 1628
CHAMPAIGN, IL 61820
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Technical Hot Line: (217) 359-2691
(answered only when technician Is available)
CP/M REGISTERED TRADEMARK DIGITAL RESEARCH
Listing 2 continued:
172 X<=Y?
173 GTO 89
174 RHH
175 STO 18
176 XEQ 15
177 ROH
178 KEG 16
179 127
188 RCCOL
181 XEQ 17
182 XEQ 12
133 RTH
134
185
136
187
133
189
198
191
192
19:
194
195
196
197
193
199
288
281
282
283
♦LBL 89
STO 18
XEQ 15
RBH
XEQ 16
127
flCCOL
ADV
RTH
♦LBL 15
I
X>Y?
RTH
RTH
31
flCCKR
RDM
GTO 15
greater than the maximum;
if so, executes LBL 09.
Otherwise, the bar is
built up by LBL 15
and LBL 16.
Special routine for
a bar that must fill
the entire width of
the graph.
Accumulates the maximum
integer number of gray-tone
characters (standard char-
acter 31) that will fit in
the bar.
284*LBL 16
285 1
286 X>Y?
287 RTH
288 X=Y?
289 RTH
210 42
211 flCCOL
Finishes a bar by
212 RDH
accumulating individual
213*-
columns until actual
214 1
length eguals specified
215 X>Y?
length.
216 RTH
217 X=Y?
213 RTH
219 35
228 RCCOL
221 RDH
222 -
223 GTO 16
224»LBL 17
225 RCL 18
226 1
227 +
223 RCL 17
229 X*8?
Inserts space from
238 X<=Y?
end of bar to maximum Y
231 RTH
then adds a marker for
232 STO 18
maximum Y
233 XOY
234 -
235 SKPCOL
236 119
237 flCCOL
233 RTH
239*LBL
18
240
RCL
13
241
-
242
RCL
16
243
*
244
FIX
8
245
RND
246
FIX
c
247
RTH
248
►LBL
11
249
BBS
258
sf ;
IT
251
LOG
1CA
C-JC
cf :
e
253
IHT
254
5
L.JJ
+
256
7
257
*
258
RTH
259»LBL
12
268
135
261
RCL
18
262
-
263
SKPC
OL
264
119
265
flCCOL
266
ADV
267
RTH
268*LBL
58
269
ADV
278
ADV
271
BEEF
272
EHB
Calculates the length
of the bar.
Calculates width of
a number (eg: axis or
extrema labels) in number
of columns.
Adds space to fill out a
line, other than a line with
a bar, then prints a Y -
maximum marker.
Beeps to mark finish.
RACET SORTS - RACET UTILITIES - RACET computes - RACET SORTS - RACET UTILITIES - RACET computes — RACET SORTS - RACET UTILITIES - RACET computes -
HARD DISK MULTIPLEXOR
F0RTHETRS-80*Modll
NOW YOU CAN HAVE THAT LARGE COMMON DATA BASE! !
• Allows up to 4 Mod ll's to connect to a single controller — up to 4 hard disk
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• Uses Cameo controller and standard 10-megabyte cartridge (hard) disk drives
along with RACET Hard/Soft Disk System (HSD) software.
• Access times 3 to 8 times faster than floppy. Mixed floppy/hard disk operation
supported.
• Compatible with your existing TRSDOS programs — you need only change
filenames! All BASIC statements are identical.
• A single file may be as large as one disk. Alternate mode allows 24-million
byte record range. Directory expandable to handle thousands of files.
• Includes special utilities — XCOPY for backup and copies, XPURGE for multiple
deletions, DCS directory catalog system, and Hard Disk Superzap. FORMAT
utility includes options for specifying sectors/gran, platters/drive, logical
disk size, etc.
HARD DISK DRIVES CONTROLLER $5995 RACET HSD Software $400
Call for multiuser pricing. Dealers call for OEM pricing.
BASIC LINK FACILITY 'BUNK' $25 Mod I, $50 Mod II
Link from one BASIC program to another saving all variables! The new program
can be smaller or larger than the original program in memory. The chained program
may either replace the original program, or can be merged by statement number.
The statement number where the chained program execution is to begin may be
specified! (Mod I Min 32K 1-disk)
INFINITE BASIC (Mod I Tape or Disk) $49.95
Extends Level II BASIC with complete MATRIX functions and 50 more string
functions. Includes RACET machine language sorts! Sort 1000 elements in 9
seconds! ! Select only functions you want to optimize memory usage.
INFINITE BUSINESS (Requires Infinite BASIC) $29.95
Complete printer pagination controls — auto headers, footers, page numbers.
Packed decimal arithmetic — 127 digit accuracy +, -,*,/. Binary search
of sorted and unsorted arrays. Hash codes.
BASIC CROSS REFERENCE UTILITY (Mod II 64K) $50.00
SEEK and FIND functions for Variables, Line Numbers, Strings, Keywords. 'All'
options available for line numbers and variables. Load from BASIC — Call with
'CTRL'R. Output to screen or printer!
DSM $75.00 Mod I, $150.00 Mod II
Disk Sort/Merge for RANDOM files. All machine language stand-alone package for
sorting speed. Establish sort specification in simple BASIC command File. Execute
from DOS. Only operator action to sort is to change diskettes when requested!
Handles multiple diskette files! Super fast sort times — improved disk I/O times
make this the fastest Disk Sort/Merge available on Mod I or Mod II.
(Modi Min 32K 2-drive system. Mod II 64K 1 -drive)
UTILITY PACKAGE (Mod II 64K) $150.00
Important enhancements to the Mod II. The file recovery capabilities alone will pay
for the package in even one application! Fully documented in 124 page manual!
XHIT, XGAT, XCOPY and SUPERZAP are used to reconstruct or recover date Irom
bad diskettes! XCOPY provides multi-file copies, 'Wild-card' mask select, absolute
sector mode and other features. SUPERZAP allows examine/change any sector on
diskette include track-0, and absolute disk backup/copy with I/O recovery. DCS
builds consolidated directories from multiple diskettes into a single display or
listing sorted by disk name or file name plus more. Change Disk ID with DISKID.
XCREATE preallocates files and sets 'L0F' to end to speed disk accesses. DEBUGII
adds single step, trace, subroutine calling, program looping, dynamic disassembly
and more!!
DEVELOPMENT PACKAGE (Mod II 64K) $125.00
Includes RACET machine language SUPERZAP, Apparat Disassembler, and Model
II interface to the Microsoft 'Editor Assembler Plus' software package including
uploading services and patches for Disk I/O. Purchase price includes complete
copy of Editor Assembler + and documentation for Mod I. Assemble directly into
memory, MACRO facility, save all or portions of source to disk, dynamic debug
facility (ZBUG), extended editor commands.
C0MPR0C(Modl — Disk only) $19.95
Command Processor. Auto your disk to perform any sequence of instructions that
you can give from the keyboard. DIR, FREE, pause, wait for user input. BASIC, No.
of FILES and MEM SIZE, RUN program, respond to input statements, BREAK,
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£T RACET COMPUTES -Z£
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RACET SORTS - RACET UTILITIES — RACET computes — RACET SORTS - RACET UTILITIES — RACET computes — RACET SORTS — RACET UTILITIES — RACET computes -
134 January 1981 © BYTE Publications Inc
Circle 83 on Inquiry card.
Circle 84 on inquiry card.
Accounting
Thousands of SoftwareHows'"users agree — SoftwareHows
products set a new standard of excellence for solution-oriented
software. Instant installation for your system, powerful "word
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features make this SolutionWare'" the only serious choice for
your needs.
Why settle for a piece
when you can have
the whole pie?!
At last! An integrated system of business
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How often have you purchased software
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chase Ordering System when a part is or-
dered ,into Inventory when it arrives, Payabje*
when it's invoiced and General Ledger when
it's paid for? Can you easily link your Account-
ing Data Base with your word processing software
to create personalized letters, reports, notices and
announcements?* Does your Point of Sale, Order
Entry software also save a keyed file which may later
be Sorted for over 60 customer characteristics and used
to generate personalized sales literature?
If you don't like your answers to these questions, your accounting
software is costing you money!
The Data Base Integration™ System from SoftwareHows "does all
this and much more! This newest software product offers the
perfect blend of performance, price and flexibility. Every single
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data base is unique. You'll be amazed at how much better you'll
understand the operation and cash flow of your business! And
better understanding means better planning — and higher profits
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The Data Base Integration System is built around the basic four
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a division of MicroDaSys
PO Box 36275 Los Angeles, CA 90036
(213)731-0876 TWX:9 10-32 1-2378
Text continued from page 130:
peripheral devices. A cassette recorder could provide
mass storage and would make feasible operations on
large blocks of data. An x,y plotter could be driven very
efficiently by the HP-41C, albeit at a leisurely pace. With
a fairly simple interface, it should be possible to connect
the calculator to a computer system. The likelihood that
any of these products will ever be forthcoming is un-
known. It is probably too much to ask that Hewlett-
Packard release technical information on the signals
available at the ports so that others could develop plug-
compatible devices. Some intrepid experimenter with a
logic probe may do it anyway.
There are a few gaps in the instruction set of the HP-
41C that should not be perpetuated in future calculators.
For example, there are tests for x < y, for x < y and for
x > y, but there is no test for x > y. Of course, any
desired logic function can be fabricated out of the existing
instructions, but the programmer should not have to go
to that trouble and should not have to remember which
of the tests is the missing one.
The most fundamental defect in the architecture of the
HP-41C, inadequate numerical precision, is a serious
flaw indeed. Numbers are represented, both internally
and in the display, with 10 decimal digits; there are no
guard digits. As a result, inaccuracies are quite often in-
troduced into the least-significant digit. For example,
(■s/2) 2 is evaluated by the calculator as 1.999999999. For
operations on some data, the corruption goes still deeper
and 2 or 3 digits become suspect. There is something ab-
surd about the world's fanciest calculator not being able
NOW. . .Continuous Checks
That Can be Used With or Without Your Computer! !
The Best in A Home Checking System
That's right. Continuous Checks in a 3-to-a-page
desk set design that can be computer printed or
handwritten - just as you now do your present
home checks.
VERSATILE
Our checks are not a high-volume business form
adaptation. They're especially designed for the
home or low volume user. Now, you don't have
to change your check writing habits just to use
your computer.
THOUGHTFUL FEATURES
Programming? Easy. All stub and check informa-
tion is on the same line. No need to change
tractor width either. Our checks are standaru
916" width for tractor feed printers.
COMPLETE HOME SYSTEM
When you've iinished printing your monthly
checks on your computer, store your checks and
stubs in our attractive Data Ring Binder Check-
book. Later, if you have a few checks to write
there's no need to load them into a printer - just
write a check right there at your desk as shown
above.
And, you can mail your checks in our dual
windowed envelopes to eliminate addressing
chores.
136 January 1981 © BYTE Publications Inc
UNIQUE
You won't find checks like these at any bank or
forms company. Even so, our special small
quantity printing process will give you quality
and appearance equal to any check supplier.
Color co-ordinated imprinting is standard on
blue, grey, tan, or green checks.
Standard imprinting and encoding is as shown
above (logos and multi-color printing are
optional).
Our prices are reasonable too. Two Hundred
checks are just S29.95 (envelopes $11.95}.
Five Hundred checks are $49.95 (envelopes
$23.95). Data Ring Checkbooks are only $5.95.
Special "ORDER NOW" Offer
If you order now, we'll send you a checkbook
FREE. You'll save $5.95. Just enclose a voided
check (for encoding information) with your
payment. (VISA - MasterCharge orders must
show signature, expiration date, and account
number). Or, send today for samples (sorry, we
can't make this free offer on requests for
samples) To:
to give results accurate to more than seven or eight
decimal places.
Actually, a subsidiary problem is more serious than
that. Conditional tests on data are carried out on the full
10-digit representation. Consequently, a test that effec-
tively asks "Is (V2) 2 equal to 2?" will give a false result,
which can lead a program far astray.
Listing 3: Utility routines for the HP-41C. These two routines
are the kinds of programs that can remain in memory as
resources to be drawn on by other programs, somewhat like
macro instructions in an assembly language. BAR simply prints
a heavy bar across the width of the paper to separate different
kinds of information. TAB handles the spacing of numbers to be
printed in vertical columns. It must be supplied with the number
to be printed (in the X register) and the number of character
spaces to be measured from the present position in the line of
print to the decimal point. TAB was employed in formatting the
random-number data in listing 2.
81+L8L "BfiR"
82 SUV
93 .823
84 31
85+LBL 61
96 OCCHR
67 I3G Y
93 GTO 81
89 FRBUF
18 BDV
11 flDV
12 END
SYNERGETIC
SOLUTIONS
4715 SHEPHERD RD.
MULBERRY, FL
33860
01»LBL ■
82
BBS
S3 SF 25
84 LOG
85
CF 25
86
X<=8?
07
CLX
88
INT
89
1
IS
+
11
RCL X
12
3.1
13
/
14
hit
15
+
16
CHS
17
+
13
SKPCH
TfiB"
19 END
Listing 4: Random-number routines for the HP-41C. These two
random-number generators, standard coding exercises for pro-
grammable calculators, both calculate a pseudorandom real
value, then select a single pseudorandom digit for return to the
calling program. RDM LC employs the standard linear-
congruential method, which has virtues and failings that are
well understood. In this example, R n * , is equal to [24,298R„ +
yy^yllmod 199,017.
RDM LN is an algorithm the author stumbled upon but has
not seen in the literature. R„ t , is defined as 1/ln R„. Experimen-
tal runs of up to several thousand iterations have given good
results, but the behavior of the algorithm is not understood. A
sample test is shown in listing 5.
9ULBL "RDM LN"
02 RCL 28
03 HBS
04 LN
85 1/X
96 STO 20
87 1 E3
08 *
09 FRC
18 18
11 *
12 INT
13 A8S
14 END
81»LBL "RDH LC"
02 RCL 28
03 24298
04 *
05 99991
86 +
87 199817
08 MOD
09 STO 28
18 1 E3
/
12 FRC
13 10
14 *
15 INT
16 END
11
Circle 85 on Inquiry card.
Look
's happened to
HIPL0T
TM
$1,385-
It's grown into a complete
family of quality low cost digital plotters
In just two short years, The
HIPL0T has become the most
popular digital plotter among
small systems users. With a
record like that, what can we do
for an encore? WE'VE IN-
TRODUCED A COMPLETE LINE
OF HIPL0TS...with a model
suited for just about every plot-
ting application.
The HIPL0T DMP Series is a
new family of digital plotters
with both "standard" and "in-
telligent" models available with
surface areas of 8 1 /2" x 11" (DIN
A4) and 11" x 17" (DIN A3). For
the user needing a basic reliable
plotter, we have the "old stan-
dard" DMP-2 (8 1 / 2 " x 1 1 ") and the
"new standard" DMP-5 (11" x
17"). For those needing a lit-
tle more capability, there are
the DMP-3 (8V2" x 11") and
the DMP-6 (11" x 17")-both
TM HIPLOT and DM/PL are Trademarks
of Houslon Instrument
Yes, they are UL listed! *
microprocessor controlled and
providing easy remote position-
ing of the X and Y axes (perfect
for the OEM). For those who
want this intelligence plus the
convenience of front panel elec-
tronic controls, we've provided
the DMP-4 (8 1 /2" x 11") and the
DMP-7(11" x 17").
The "standard" plotters come
complete with an RS-232-C and
a parallel interface. The "intel-
ligent" DMP plotters accept data
from either an RS-232-C or Centronics
data source. For the "standard" plot-
ters, software is available from
our ever expanding "Micrographic
Users Group." The "intelligent"
HIPLOTs use our exclusive
DM/PL™ language which min-
inimizes plot software to a
fraction of that normally as-
houston instrument
GRAPHICS DIVISION OF
BAUSCH&LOMB
Circle 86 for literature
Circle 87 to have representative call
sociated wth digital plotting.
With the new DMP Series,
high quality digital plotting can
now be a part of your system. It
just doesn't make sense to be
without this valuable tool when
there is a DMP plotter with the
plot size, speed and capabilities
that are exactly tailored to your
specific needs. ..and your
budget.
Prices for the DMP series
range from $1,085* to $1,985*.
For complete information con-
tact Houston Instrument. One
Houston Square, Austin, Texas
78753. (512) 837-2820. For rush
literature requests, outside Texas
call toll free 1-800-531-5205. For
technical information ask for
operator #5. In Europe contact
Houston Instrument, Rochester-
laan 6, 8240 Gistel, Belgium.
Telephone 059/27-74-45.
'U.S. suggested retail prices only.
DMP 2, 3 and 4 UL listed
DMP 5, 6 and 7 UL listing pending
DELIVER! ||
n VANDATA y
Business Software <zj
Before you buy the programs that your company is going to
depend on for its accounting, ask the following questions:
Do I get the source (Don't settle for less.
code? You cannot make the
smallest change without it.)
Is it well documented? (The Osborne documen-
tation is the best.)
Is it fully supported? (If not, why not? What are
they afraid of?)
The Osborne system is the industry standard accounting
package, with literally thousands of users. We offer an en-
hanced version of that package that will run on most systems
without recompiling.
CRT INDEPENDENCE. The original programs were
designed to run on a Hazeltine terminal. To use a different
CRT, you had to modify and test two modules — and recom-
pile every program! With the Vandata package, you simply
pick your CRT from a menu and run.
FILE/DRIVE MAP. The original package had all data files
on the same drive as the programs. Ours allows you to
dynamically specify the drive assigned to each file. In fact, you
can change the drive assignments whenever you wish, to ac-
commodate expanded file sizes or new hardware — all
without recompiling!
INTEGRATION. The original AR and AP systems had to
be changed and recompiled to feed journal entries to GL. Our
installation program eliminates this hassle. It simply asks you if
you want the systems integrated, and what your special ac-
count numbers are.
SPEED. The original programs used a binary search to ac-
cess the GL account file. We use an enhanced technique that
greatly cuts down on disk accesses, thus speeding up account
lookups significantly in the GL, AR and AP systems.
BUGS. We have corrected a number of bugs in the original
programs. If you find a bug in our programs, we'll fix it — and
send you a $20 reward! Our users are sent bug fixes in source
form.
MORE! We have made many minor enhancements, and
fixed many minor problems. We are committed to the ongoing
support of our package. Vandata has been an independent
software supplier for over seven years. Quality and support are
our way of doing business.
General Ledger with Cash Journal . . $95
Accounts Receivable $95
Accounts Payable $95
Payroll with Cost Accounting $95
• All Four Packages (GL, AR, AP, PR) $295
Magic Wand (Super Word Processor!!) $345
Pearl Level III (best prog, tool available) $645
CBASIC-2 $110
TRS-80® MODIICP/M® 2.2 (Pickles & Trout) $185
H89/Z89 CP/M® 2.2 (Magnolia Microsystems)$249
Formats: Sid. 8". 5" NorthStar DD. TRS-80 MOD II", H89/Z89 Manuals lor
GL, AR/AP. and PR are not included in price — add $20 per manual desired
(AR/AP are in one manual). CP/M- ! and CBASIC-2 required lo run accounting
software Users must sign licensing agreement Dealer inquiries invited.
To order call: (206) 542-8370
or write: VANDATA
17541 Stone Avenue North
Seattle, WA 98133
CP/M® is a registered trademark ot Digital Research.
TRS-80® is a registered trademark ot Radio Shack, Inc.
Listing 5: Bar-graph results of the CHART program, given in
listing 2. The graph represents pictorially the distribution of the
10 digits in a sample of 2500 pseudorandom numbers. The
numbers were generated by another program, RDM LN (shown
in listing 4), with the bookkeeping done by a third program.
Tesi of
•
RDM LN"
Plot of "RANDOM"
Nufiber
3f
trials 2538
mmimnmmmmi
Seed =
1
234567890
V.l Y-»
uiuu
mu
286.80 389.88
! 258.00
mMMMM 1
DIGIT i
1 1
<l>SIfSIHS3l?3
MEAN =
25S.08
1 1
1 i
<2>liIiIBI! !
<9> =
237.
1 1
1 1
<1> =
259.
<3>aiIIS 1
<2> =
234.
f 1
<3> =
22S,
<4>mnsiinia
<4> =
256.
i i
i i
<5> =
265.
<5>IM«IIiiI.«H
<6> =
268.
1 1
1 1
\ I f ~
251.
<6)IKiIII!III£ifII
/0\ ~
259.
1 1
<9> =
243.
<7>fiSlllIlli !
1 I I
i I I
<3>BIISSP*i«l :
RUNS OF
d
211.
I 1 1
RUNS OF
3
14.
<9>liiiIIIH 1 1
RUNS OF
4
3.
i i I
RUNS OF
e
J
8.
STATISTICS
CHI SQUARED = 6.3248
HIGH/LOW = 1.8593
ODD/EVEN = 8.9936
ISISIlIIIIillllilllilHI
It is easy to imagine that some programmable
calculator evolved from the HP-41C would have instruc-
tions much like those of a higher-level language. Having
introduced named programs, the next obvious step is
named variables, which would relieve the programmer of
much tedious worry over memory allocation. Let the
machine keep track of where the numbers are; it does so
better than people can. The existing conditional tests,
which act directly on particular registers, might be recast
as a more general if . . . then . . . else construction,
employing the named variables. Also, do . . . while and
repeat . . . until commands would be a welcome addi-
tion; indeed, the loop-control instructions of the HP-41C
already come close.
One essential capability must be added to the
calculator before such higher-level commands can be
made available. A higher-level language is a program
whose output is another program, and so it is necessary
that instructions be allowed to operate not only on data
but also on other instructions. In this context, it seems
significant that the inability of a calculator to alter its
own instructions is what most clearly distinguishes
calculators from computers. ■
138 January 1981 © BYTE Publications Inc
Circle 88 on inquiry card.
INVEST IN PRODUCTIVITY
Are you responsible for introducing modern
office systems into your organization?
Is your department going to be a user of such
systems?
Do you design, plan, make, or market such
systems?
If so, you should plan now to attend the second
annual Office Automation Conference in Houston,
Texas, March 23-25.
More than a showcase for the latest office auto-
mation equipment, the Conference provides a
unique forum in which you can learn from experts
how to harness and integrate today's worksaving
devices for maximum gains in productivity
In addition to 150 informative exhibits, you'll be
able to attend over 50 special learning sessions.
Sessions covering topics as diverse as: Feasibility
Studies. ..Organizational Impact. ..Electronic Mail...
Teleconferencing.. .Merger of Voice with Text and
Data... State of the Art in Word Processing.
Don't miss this opportunity to see and hear
what's new in office automation and turn what you
learn into greater productivity for you.
For Conference information, call or write Office
Automation Conference c/o AFIPS, PO. Box 9659,
1815 N. Lynn Street, Arlington, VA 22209 (703)558-3610.
For discount air fares, airline reservations, hotel
and show information, or to pre-register, call toll-free
(800) 556-6882.
See you in Houston!
THE 1981 OFFICE AUTOMATION CONFERENCE
HOUSTON, TEXAS MARCH 23-25
Circle 244 on inquiry card.
BYTE January 1981 139
No.18
Software with
full support
Purchasing our software is just the
beginning. We then back it up with
professional support:
■ Subscription to "LIFELINES" for automatic
notifications of revisions! ■ Update service for
software and documentation! ■ Telephone
Hotline! ■ Overseas software export service!
AM Lifeboat programs require CP/M, unless otherwise stated.
ilinull/ Alor
Munutl / Al
^
LJCP/M* FLOPPY DISK OPERATING SYS-
TEM— Digital Research's operating system
configured for many popular micro-computers
and disk systems:
System Version Price
Apple II* 2.x .. . .349/NA O
SoftCard* with Z80
Microsoft BASIC version 5
with high resolution
graphics
North Star Single Density . . 2.x . . . .170/25 ®
North Star Double/Quad . . . 2.x . . . .170/25 ®
Durango F-85 2.x .. . .170/25
iCOM Micro-Disk 241 1 1 .4 . . . .145/25
iCOM 3712 for MITS
88-2SIO Console 1.4 .. . .170/25 "
iCOM 3712 for 3P+ S/MITS
SIO Rev non-zero console 1 .4 . . . .170/25 "
iCOM 3812 2.x .. . .225/25 ®
JCOM3812 1.4... . 170/25 *
iCOM 451 1/Pertec D3000 . . 2.x . . . .375/25 •+
Mils 3202/Altair 8800 1 .4 . . . .145/25
Heath H8 + H17 1.4... .145/25 ®
Heath H89 by Magnolia .... 2.x .. . .249/25 O
Ohio Scientific C3 2.x .. . .200/25
Ohio Scientific C3-C 2.x .. . .250/25
Onyx C8001 Standard 2.x .. . ,250/25
Onyx C8001 Enhanced .... 2.x .. . ,330/25
TRS-80 Model I 1 .4 . . . .145/25 ©
TRS-80 Model II 2.x ,. . .170/25
TRS-80 Model II + Corvus . 2.x . . . .250/25
Processor Technology
Helios II 1.4.... 145/25
Intel MDS Single Density . . . 2,x 170/25
Intel MDS Double Density , . 2.x . . . .170/25
i jf Micropolis Mod I 2.x 200/25 ®
k/Otv]* Micropolis Mod II 2.x ., . .200/25 ®
'V Jl Mostek MDX STD
Bus System 2.x... ,350/25 "
HARD DISK OPTIONS (items with ®) when
purchased with CP/M 2.X system.
Corvus Add 80.
Konan Phoenix Add 80.
ICOM 451 1/Pertec D3000 Add 80.
Software consists of the operating system, text
editor, assembler, debugger and other utilities
for file management and system maintenance.
Complete set of Digital Research's documen-
tation and additional Implementation notes in-
cluded. Systems marked * and " include firm-
ware on 2708 and 2716. Systems marked -In-
clude 5440 media charge. Systems marked
® require the special ® versions of soft-
ware in this catalog. O includes hardware ad-
dition to allow our standard versions of
software to run under It.
L.Z80 DEVELOPMENT PACKAGE-Consists
® of: (1) disk file line editor, with global inter and
® Intra-line facilities; (2) Z80 relocating assem-
bler, Zllog/Mostek mnemonics, conditional as-
sembly and cross reference table capabilities;
(3) linking loader producing absolute Intel hex
disk file $95/520
DZDT— Z80 Monitor Debugger to break and
'" examine registers with standard Zilog/
© Mostek mnemonic disassembly displays. S35
when ordered with Z80 Development
Package S50/S10
AVOCET SYSTEMS
D XASM-68— Non-macro cross-assembler with
nested conditionals and full range of pseudo
operations. Assembles from standard Motorola
MC6800 mnemonics to Intel hex . , ,S200/$25
□ XASM-65-As XASM-68 for MOS Technology
MCS-6500 series mnemonics S200/S25
□ XASM-4B- As XASM-68 for Intel MCS-4B and
UPI-41 families S200/S25
D X ASM-1 8- As XASM-68 for RCA 1 802
$200/525
Ll'DISTEL— Disk based disassembler to Intel
8080 or TDL/Xitan Z80 source code, listing and
cross reference files, Intel or TDL/Xitan pseudo
ops optional. Runs on 8080 S65/S10
DDISILOG-As DISTEL to Zilog/Mostek
® mnemonic files S65/S10
©
DSMAL/80 Structured Macro Assembler
® Language — Package of powerful general
purpose text macro processor ana SMAL
structured language compiler. SMAL is an as-
sembler language with IF-THEN-ELSE,
LOOP-REPEAT-WHILE, DO-END. BEGIN-
END constructs. Not compatible with CP/M
version 2 or greater $75/51 5
□ RAID — 8080/8085 debugging aid and general
system utility program. Both a software
emulator and real-time debug monitor. Fea-
tures multiple breakpoints, symbolic input,
symbolic display and altering of registers, built-
in assembler & dis-assembler, tracing, single-
stepping, memory protection, histograms,
memory search, direct disk access. Requires
ZP/W
w
32K CP/M
.S250/S25
PHOENIX SOFTWARE ASSOCIATES
DPASM* — Z80 macro assembler, Intel/TDL
© mnemonics. Generates Intel hex format or re-
locatable code in either TDL Object Module
format or PSA Relocatable Binary Module for-
mat. Supports text insertion, conditional
branching within macros, recursive macro calls
and parameter passing $129/325
□ EDIT— Character oriented text file editor. In-
© eludes macro definition capabilities. Handles
insertion, deletion, searching, block move, etc.
for files of any length. Does not require a
CRT. $129/$25
□ PLINK'-Two pass disk-to-disk linkage edl-
ffl tor/loader which can produce re-entrant,
ROMable code. Can link programs that are
larger than available memory for execution
targeted on another machine. Full library
capabilities. Input can be PSA Relocatable Bi-
nary Module, TDL Object Module or Microsoft
REL files. Output can be a COM file, Intel hex
file, TDL Object Module or PSA Relocatable
file $129/525
D BUG* and ^BUG'— Z80 interactive machine
©level debugging tools lor program develop-
ment, BUG "has full mnemonic trace and In-
teractive assembly (mnemonics compatible
with PASM). Dynamic breakpoints and condi-
tional traps while tracing (even through ROM!),
^BUG is a subset of BUG and is used in mem-
ory limited situations $129/$25
DIGITAL RESEARCH
□ MP/M- Installed for single density MDS-800.
Multi-processing derivative of the CP/M op-
erating system. Manual includes CP/M?
documentation $300/$50
□ MAC— 8080 Macro assembler. Full Intel macro
©definitions. Pseudo Ops Include RPC, IRP,
REPT, TITLE, PAGE, and MACLIB. Produces
absolute hex output plus symbol table file for
use by SID and ZSID (see below) ..$120/515
□ SID— 8080 Symbolic debugger. Full trace.
© pass count and breakpoint program testing.
Has backtrace and histogram utilities. When
used with MAC, provides full symbolic display of
memory labels and equated values ,$105/515
DZSID— ZB0 Symbolic debugger with all fea-
ts tures of SID 5130/S15
®
□ TEX— Text output formatter to create paglnat-
®ed, page-numbered and justified copy. Output
can be directed to printer or disk . . .5105/515
□ DESPOOL— Utility program to permit simulta-
©neous printing from text (lies while executing
other programs 5B0/S10
□ tiny C— Interactive interpretive system for
® teaching structured programming techniques.
Manual Includes full source listings .$105/550
□ BDS C COMPILER- Supports structures,
® unions, 2 dimensional arrays, pointers, recur-
© sion and overlays. Features optimized code
generator, variable sized buffers for file I/O, and
capability to produce ROMable code. Includes
macro package to enable user to produce link-
able modules with MAC (see under Digital Re-
search). Floating point functions, full run-time
package and machine code library sources
provided. Linker, library manager and textbook
included. Compiler lacks Initializers, statics,
floats and longs $145/525
□ WHITESMITHS C COMPILER-The ultimate
©In systems software tools. Produces faster
® code than a pseudo-code Pascal with more
extensive facilities. Conforms to the full UNIX"
Version 7 C language, described by Kernighan
and Ritchie, and makes available over 75 func-
tions for performing I/O, string manipulation
and storage allocation. Linkable to Microsoft
REL files. Requires 60K CP/M 5630/530
MICROSOFT iMmtS'i/Moiw
□ BASIC-80-Disk Extended BASIC. ANSI
©compatible with long variable names.
©WHILE/WEND, chaining, variable lenglh file
records. MBASIC version 4.51 also included on
disk 5325/525
□ BASIC COMPILER— Language compatible
© with BASIC-80 and 3-10 times faster execution.
® Produces standard Microsoft relocatable bi-
nary output. Includes MACRO-80. Also linkable
to FORTRAN-80 or COBOL-80 code
modules S350/525
□ FORTRAN-80-ANSI 66 (except for COM-
© PLEX) plus many extensions. Includes relocat-
® able object compiler, linking loader, library with
manager Also includes MACRO-80 (see
below) $425/525
□ COBOL-80-Level 1 ANSI 74 standard plus
© most of Level 2. Full sequential, relative, and
® indexed file support with variable file names.
Powerful interactive, formatted screen handling
with ACCEPT and DISPLAY verbs. Program
segmentation for execution of programs larger
than memory and CHAIN command with pa-
rameler passing. Full support of CP/M version
2 files. Includes MACRO-80 (see above), link-
ing loader, and relocatable library manager.
Requires 48K CP/M $700/$25
□ M/SORT— Optional sort/merge capability for
©COBOL-80 which conforms fully to SORT/
MERGE, Level II of the 1974 ANSI COBOL
standard (except COLLATING SEQUENCE IS
alphabet-name). Requires COBOL-80. Sold as
an update to COBOL-80 $150/510
COBOL-80 + M/SORT $825/$35
□ MACRO-80-8080/Z80 Macro Assembler.
© Intel and Zilog mnemonics supported. Relocat-
®able linkable output. Loader, Library Manager
and Cross Reference List utilities
included S149/S15
□ XMACRO-86 — 8086 cross assembler. All
© Macro and utility features of MACRO-80 pack-
age. Mnemonics slightly modified from Intel
ASM86. Compatibility data sheet
available S275/S25
□ EDIT-80— Very fast random access text editor
® for text with or without line numbers. Global and
intra-llne commands supported. File compare
utility included $89/515
□ muSIMP/muMATH — muSIMP is a high level
© programming language suitable for symbolic
and semi-numerical processing implemented
using a fast and efficient interpreter requiring
only 7K bytes of machine code. muMATH is a
package of programs written in muSIMP The
package performs sophisticated mathematical
functions, Keeps track of up to 611 digits. Per-
forms matrix operations on arrays: transpose,
multiply, divide, inverse and other integer pow-
ers. Logarithmic, exponential, trigonometric
simplification and transformation, symbolic dif-
ferentiation with partial derivatives, symbolic in-
tegration of definite and indefinite integrals,
Requires 40K CP/M $250/$20
□ muLISP-60— Microcomputer implementation
© of LISP. The interpreter resides in only 7K bytes
of memory yet includes 83 LISP functions. Has
infinite precision integer arithmetic expressed
in any radix from 2 to 36. muLISPSO includes
complete trace facility and a library of useful
functions and entertaining sample
programs $200/515
□ PASCAL/M* — Compiles enhanced Standard
® Pascal to compressed efficient Pcode, Totally
CP/M compatible. Random access files. Both
16 and 32-bit Integers. Runtime error recovery.
Convenient STRINGS. OTHERWISE clause on
CASE. Comprehensive manual (90 pp, In-
dexed), SEGMENT provides overlay structure.
INPORT, OUTPORT and untyped files for arbi-
trary I/O. Requires 56K CP/M. Specify 1) 8080
CP/M, 2) Z80 CP/M. or 3) Cromemco
CDOS 5175/520
□ PASCAL/Z-Z80 native code PASCAL com-
® pller. Produces optimized, ROMable re-entrant
©code. All interfacing to CP/M Is through the
support library. The package Includes compiler,
relocating assembler and linker, and source
for all library modules. Variant records, strings
and direct I/O are supported, Requires 56K
CP/M $395/525
□ PASCAL/MT- Subset of standard PASCAL,
©Generates ROMable 8080 machine code.
® Symbolic debugger Included. Supports inter-
rupt procedures, CP/M file I/O and assembly
language interface. Real variables can be BCD,
software floating point, or AMD 9511 hardware
floating point. Includes strings enumerations
Sotlwar* /
wild /Mi
M.11U.I/ All
* t
and record data types. Manuafexplains BASIC- Vj
PASCAL conversion. Requires 32K ,S250/S30\k
□ APL/V80— Concise and powerful language for
© application software development. Complex
programming problems are reduced to simple
expressionsTn APL. Features include up to 27K
active workspace, shared variables, arrays of
up to 8 dimensions, disk workspace and copy
object library. The system also supports auxil-
iary processors for interfacing I/O ports. Re-
quires 48K CP/M and serial APL printing termi-
nal or CRT $500/530
LJALGOL-60— Powerful block-structured lan-
©guage compiler featuring economical run-time
dynamic allocation of memory. Very compact
(24K total RAM) system implementing almost
all Algol 60 report features plus many powerful
extensions including string handling direct disk
address I/O etc $199/520
□ CBASIC-2 Disk Extended BASIC-Non-
® interactive BASIC with pseudo-code compiler
and run-time interpreter. Supports full file con-
trol, chaining, integer and extended precision
variables, etc. Versions of CRUN for CP/M ver-
sions 1.4 and 2.x included on disk. . .$120/515
•
MICRO FOCUS
] STANDARD CIS COBOL- ANSI 74 COBOL
) standard compiler fully validated by U.S. Navy
tesls to ANSI level 1 . Supports many features to
level 2 including dynamic loading of COBOL
modules and a full ISAM file facility. Also, pro-
gram segmentation, interactive debug and
powerful interactive extensions to support pro-
tected and unprotected CRT screen formatting
from COBOL programs used with any dumb
terminal S850/S50
] FORMS 2— CRT screen editor. Output is
) COBOL data descriptions for copying into CIS
COBOL programs. Automatically creates a
query and update program of indexed files
using CRT protected and unprotected screen
formats. No programming experience needed.
Output program directly compiled by STAN-
DARD CIS COBOL 5200/S20
J NEVADA COBOL- Subset of ANSI-74. Fea-
tures fast compilation and execution with small
object modules. Has extended arithmetic with
18 digit accuracy. Extended I/O includes ran-
dom access files and sequenlial files of both
fixed and variable lenglh records, and interac-
tive accept/display verbs. Good error mes-
sages and debugging facilities enhance pro-
gram development. Requires a 32K CP/M
system S149/S25
EIDOS SYSTEMS
JKBASIC-Microsoft Disk Extended BASIC
) version 4.51 integrated with KISS Multi-Keyed
Index Sequenlial and Direct Access file man-
agement as 9 additional BASIC commands.
KTSS included as relocatable modules linkable
to FORTRAN-80, COBOL-80. and BASIC
COMPILER, Specify CP/M version 1.4 or 2.x
when ordering. Requires 48K CP/M S585/S45
To licensed users of Microsoft BASIC-80
(MBASIC) S435/S45
JXYBASIC Interactive Process Control
BASIC— Full disk BASIC features plus unique
commands to handle byte rotate and shift and
to test and set bits. Available in several ver-
sions:
Integer ROM squared 5350/525
Integer CP/M 5350/$25
Extended ROM squared $450/$25
Extended CP/M 5450/525
Extended Disk CP/M -.5550/525
Integer CP/M Run Time Compiler . .S350/525
Extended CP/M Run Time CompilerS450/S25
] RECLAIM— A utility to validate media under
CP/M, Program tests a diskette or hard disk
surface for errors, reserving the imperfections
in Invisible files, and permitting conlinued
usage of the remainder. Essential for any hard
disk. Requires CP/M version 2 580/55
j BASIC UTILITY DISK-Consists of: (1)
OCRUNCH-14— Compacting utility to reduce
the size and increase the speed of programs in
Microsoft BASIC 4.51. BASIC-80 and TRS-80
BASIC. (2) DPFUN- Double precision subrou-
tines for computing nineteen transcendental
functions including square root, natural log, log
base 10. sine, arc sine, hyperbolic sine, hyper-.
bolic arc sine, etc. Furnished in source on dis-
kette and documentation 550/535
] STRING/80— Character string handling plus
routines for direct CP/M BOOS calls from
FORTRAN and other compatible Microsoft lan-
guages. The utility library contains routines that
enable programs to chain to a COM file, retrieve
command line parameters and search file direc-
tories with full wild card facilities. Supplied as
linkable modules In Microsofl format, $95/$20
DSTRING/80 source code available
separately— $295/NA
JTHE STRING BIT- FORTRAN character
I string handling. Routines to find, fill, pack,
move, separate, concatenate and compare
character strings. This package completely
eliminates the problems associated with
character string handling In FORTRAN.
Supplied with source $65/515
I VSORT— Versatile sort/merge system for fixed
D length records with fixed or variable length
fields. VSORT can be used as a stand-alone
package or loaded and called as a subroutine
from CBASIC-2. When used as a subroutine,
VSORT maximizes the use of buffer space by
saving the TPA on disk and restoring it on com-
pletion of sorting. Records may be up to 255
bytes long with a maximum of 5 fields. Upper/
lower case translation and numeric fields
supported $175/520
l IBM/CPM- Program to transfer IBM 3741 data
set files to CP/MTlles or CP/M files to IBM 3741
data sets. Easy to use. Requires two eight inch
diskette drives, 24K memory, and a 24 by 80
CRT terminal S175/S5
CPAIds*
] MASTER TAX — Professional tax preparation
) program. Prepares schedules A, B, C, D, E, R
' G, R/RP, SE, TC, ES and forms 2106. 2119,
2210, 3468, 3903. 2441. 4625, 4726. 4797.
4972. 5695 and 6251 . Printing can be on readily
available, pre-printed continuous forms, on
overlays, or on computer generated, IRS ap-
proved forms. Maintains client history files and
Is interactive with CPAids GENERAL LEDGER
II (see below) 5995/S30
Annual Update Fee $350
j STANDARD TAX — As above for schedules A,
B. C. D, E. G. R/RP, SE, TC and forms 2106 and
2441, Also, does not maintain client history
files $495/S30
Annual Update Fee 5175
Copyright © 1980 Lifeboat Associates. No por-
tion ol this advertisement may be reproduced
without prior permission.
Neu In der Schwefz Lifeboat Associates GmbH, Aegeristr. 35, CH 6340 Baar Telefon 042/31 2931
ttwara /
with /Manual
linuil/ Alone
#
. GENERAL LEDGER ll-Designed for CPAs.
t Stores complete 12 monlh detailed history of
transactions. Generates financial statements,
depreciation, loan amortizations, journals, trial
balances, statements of changes in financial
position, and compilation letters. Includes
payroll system with automatic posting to gen-
eral ledger. Prints payroll register, W2's and
payroll checks S450/S30
Q T/MAKER — Powerful new tool for preparing
management reports with tabular data. Makes
financial modeling projects easy. Do you want a
weekly profitability report? Set up the table and
compute. Just change the sales figures for next
week and compute. You have a new report!
T/MAKER includes a full screen editor for
setting up tables which pages left, right, up
and down. Compute includes standard arith-
metic, percents, exponents, common tran-
scendental functions, averages, maxima,
minima, projections, etc. Requires 48K CP/M,
CBASIC-2. CRT terminal with addressable cur-
sor positioning S275/S25
UESQ-1 — Professional time and billing for the
©legal profession. Designed for use by the first-
t time computer user. Records billable and non-
51 billable time. Complete system includes trans-
nifi action entry, posting, billing, reports, and client
analysis. Records cash receipts, escrow receipts,
and escrow transfers. Requires 48K CP/M
system, 480K of disk storage space, cursor ad-
dressable CRT, and CBASJC-2 . . . .S1495/S50
.'...Complete demonstration system for ESQ-1
© S75/S50
f
tt-ar. .
with /Ml
Soltwaru /
wlih / Manual
Manual/ Alona
y
V
C J BSTAM - Utility to link one computer to another
® also equipped with BSTAM. Allows file transfers
at full data speed (no conversion to hex), with
CRC block control check for very reliable error
detection and automatic retry. We use it! It's
great! Full wildcard expansion to send *. COM,
etc. 9600 baud with wire. 300 baud with phone
connection. Both ends need one. Standard and
® versions can talk to one another. This
soltware requires a knowledge of assembler
language for installation S150/S10
□ BSTMS— Intelligent terminal program for
®CP/M systems. Permits communication be-
tween micros and mainframes. Sends charac-
ter data files to remote computers under com-
plete control. System can record character data
sent from remote computer systems and data
banks. Includes programs to EXPAND and
COMPRESS binary files for transmission. This
software requires a knowledge of assembler
language for installation S200/S25
ZDWHATSIT?*— Interactive data-base system
using associative tags to retrieve information by
subject. Hashing and random access used for
fast response. Requires CBASIC-2 .S175/S25 -\X
□ SELECTOR III-C2— Data Base Processor toV
t create and maintain multi-key data bases.
9 Prints formatted sorted reports with numerical
summaries or mailing labels. Comes with sam-
ple applications, including Sales Activity, Inven-
tory, Payables, Receivables, Check Register,
and Client/Patient Appointments, etc. Requires
CBASIC-2. Supplied in source S295/S20
□ GLECTOH— General Ledger option to
SELECTOR III-C2. Interactive system provides
for customized COA. Unique chart of transac-
tion types insure proper double entry book-
keeping. Generates balance sheets. P&L
statements and journals. Two year record al-
lows for statement of changes in financial posi-
tion report. Supplied in source. Requires
SELECTOR ll[-C2. CBASIC-2 and 56K
system $350/$25
MAGSAM III — Sophisticated keyed access file
© support system. Supports random, sequential,
and generic retrieval by key. Also, multiple sec-
ondary keys. Dynamic allocation and extension
of files with automatic free space reclamation.
Interactive tutorial included to get the user
started, Complete with documentation and
quick reference card, Specify CBASIC or Mi-
crosoft BASIC version. Requires 48K
system S145/S25
□ MAGSAM IV — High speed machine code ver-
©sion of MAGSAM III for CBASIC only. Distrib-
uted as pre-loaded modules and Microsofl re-
locatable object modules S295/S2S
G DATASTAR— Professional forms control entry
© and display system for key-to-disk data cap-
ture. Menu driven with built-in learning aids.
Input field verification by length, mask, attribute
(i.e. uppercase, lowercase, numeric, auto-dup,
etc.). Built-in arithmetic capabilities using keyed
data, constant and derived values. Visual feed-
back for ease of forms design. Files compatible
with CP/M-MP/M supported languages. Re-
quires 32K CP/M and CRT with addressable
cursor S350/S35
DWORD-STAR— Menu driven visual word pro-
© cessing system for use with standard terminals.
Text formatting performed on screen. Facilities
for text paginate, page number, justify, center
and underscore. User can print one document
while simultaneously editing a second. Edit
facilities include global search and replace,
Read/Write to other text files, block move. etc.
Requires CRT terminal with addressable cursor
positioning S445/S40
DWORD-STAR-MAIL-MERGE-As above with
©option for production mailing of personalized
documents with mail lists from DATASTAR or
NAD S575/S40
DWORD-MASTER Text Editor- In one mode
© has superset of CP/M's ED commands includ-
ing global searching and replacing, forwards
and backwards in file in video mode, provides
full screen editor for users with serial address-
able-cursor terminal S145/S25
D MAGIC WAND*— Word processing system
with simple, easy to use full screen text editor
and powerful print processor. Editor has all
standard editing functions including text insert
and delete, global search and replace, block
move and library files for boiler plate text. Print
processor formatting commands include au-
tomatic margins, pagination, headings & foot-
ings, centered and justified text. Also prints with
true proportional spacing, merges with data
files for automatic form letters, and performs
run-time conditional testing for varied output.
Requires 32K CP/M and CRT terminal with ad-
dressable cursor ■ . . .S395/S40
D TEXTWRITER III- Text formatter to justify and
® paginate letters and other documents. Special
features include insertion of text during execu-
tion from other disk files or console, permitting
recipe documents to be created from linked
fragments on other files. Has facilities for sorted
index, table of contents and footnote insertions.
Ideal for contracts, manuals, etc. Now compati-
ble with Electric Pencil* and Word-Star pre-
pared files S125/S20
D DATEBOOK— Program to manage time just
like an office appointment book but using the
speed and memory ol a computer. Keeps track
of three appointment schedules (three dental
chairs, three attorneys, etc.) at once. Appoint-
ments consist of name, reason for the appoint-
ment, the date and time, and the length of the
appointment. System can be quickly cus-
tomized for the individual user. Many helpful
features for making, changing, finding, and re-
porting appointments. Requires 48K CP/M and
180K bytes diskette storage, Requires 80 *24
cursor addressable terminal. Specify 8080
CP/M, Z80 CP/M or Cromemco CDOS
5295/S25
DMA
□ CBS — Configurable Business System is a
t comprehensive set of programs for defining
custom data files and application systems with-
out using a programming language such as
BASIC, FORTRAN, etc. Multiple key fields for
each data file are supported. Set-up program
customizes system to user's CRT and printer.
Provides fast and easy interactive data entry
and retrieval with transaction processing.
Report generator program does complex calcu-
lations with stored and derived data, record
selection with multiple criteria, and custom for-
mats. Sample Inventory and mailing list sys-
tems included No support language
required S395/S40
MICROPRO
D SUPER-SORT I — Sort, merge, extract utility as
© absolute executable program or linkable mod-
ule in Microsoft format. Sorts fixed or variable
records with data in binary. BCD. Packed Deci-
mal. EBCDIC. ASCII, floating & fixed point, ex-
ponential, field justified, etc. Even variable
number of fields per record! S225/S25
□ SUPER-SORT It-Above available as abso-
© lute program only S175/S25
□ SUPER-SORT III- As II without SELECT/
© EXCLUDE S125/S25
PEACHTREE SOFTWARE*
D General accounting software for small busi-
© nesses. Each product can be used alone or with
t automatic posting to the General Ledger,
Supplied in source for Microsoft BASIC 4.51 .
GENERAL LEDGER $530/$40
ACCOUNTS PAYABLE S530/S40
ACCOUNTS RECEIVABLE S530/S40
PAYROLL $530/540
INVENTORY S660/S40
D Other application products supplied in source
©for Microsoft BASIC 4.51.
f MAILING ADDRESS S530/S40
PROPERTY MANAGEMENT S925/S40
GRAHAM. DORIAN SOFTWARE
SYSTEMS
□ Comprehensive accounting software written in
©CBASIC-2 and supplied in source code. Each
® software package can be used as a stand-
f alone system or integrated with the General
Ledger for automatic posting to ledger ac-
counts. Requires CBASIC-2.
GENERAL LEDGER $805/840
ACCOUNTS PAYABLE $805/S40
ACCOUNTS RECEIVABLE $805/840
INVENTORY SYSTEM $555/$40
JOB COSTING S805/S40
APARTMENT MANAGEMENT . . . .5805/540
CASH REGISTER $805/S40
D POSTMASTER— A comprehensive package
®for mail list maintenance that is completely
menu' driven. Features include keyed record
extraction and label production. A form letter
program is included which provides neat letters
on single sheet or continuous forms. Includes
NAD file translator. Requires CBASIC-2.
$150/520
STRUCTURED SYSTEMS GROUP
□ Complete interactive accounting software for
t business. Each product can be used stand-
alone or with automatic posting to the general
ledger. Each product is thoroughly tested and
very well documented.
GENERAL LEDGER $820/540
ACCOUNTS RECEIVABLE SB20/540
ACCOUNTS PAYABLE $820/540
PAYROLL $820/540
INVENTORY CONTROL S820/S40
I ] ANALYST— Customized data entry and report- C
t ing system. User specifies up to 75 data items
per record. Interactive data entry, retrieval, r-
and update facility makes information
managemenl easy. Sophisticated report
generator provides customized reports using
selected records with multiple level break- C
points for summarization. Requires a disk sort
utility such as QSORT. SUPER-SORT or
VSORT and CBASIC-2 $250/515
I iLETTERIGHT— Program to create, edit and
type letters or other documents. Has facilities to
enter, display, delete and move text, with good
video screen presentation. Integrates with NAD j^j
for form letter mailinqs $200/$25fl* w
I I NAD— Name and Address selection system. ™
Interactive mail list creation and maintenance
program with output as full reports with refer- D
ence data or restricted information for mail
labels. Transfer system for extraction and trans-
fer of selected records to create new files.
OSORT required if sorting is desired. $100/$20 □
[} QSORT— Fast sort/merge program for files
with fixed record length, variable field length
information. Up to five ascending or descend-
ing keys. Full back-up of input files created n
$100/520
• •••••*
nHEAD CLEANING DISKETTE-Cleans the
drive Read/Write head in 30 seconds. Diskette D
absorbs loose oxide particles, fingerprints, and
other foreign particles that might hinder the per-
formance of the drive head. Lasts at least 3 q
months with daily use. Specify 5' or 8".
Single sided $20 each/$55 for 3
Double sided $25 each/565 for 3 LJ
NEWSLETTER
FROM LIFEBOAT
LIFELINES is the first step in software support for the
serious microcomputer user. Each issue reports
new revisions together with information on the purpose
tor each such release, be it for correction of "bugs"
or the addition of features and facilities.
Feature Articles I New Software I Product
Comparisons I Info on CP/M Users Group I
SUBSCRIPTION INFORMATION:
$1 8 for twelve issues: U.S., Canada, and Mexico.
$40 for twelve issues; all other countries.
$2.50 for each back issue: U.S., Canada, and
Mexico.
$3.60 for each back issue: all other countries.
Send Check to LIFELINES, 1 651 Third Avenue,
New York, N.Y 1 0028 or use your VISA or
MASTERCARD-call (212) 722-1700
DC 300 Data Cartridges Specify 450'XL or
300' certified. Pack of 5 5100
FLIPPY DISK KIT- Template and instructions
to modify single sided 5Va" diskettes for use of
second side in single sided drives $12.50
FLOPPY SAVER— Protection for center holes
for 5" and 8" floppy disks. Only 1 needed per
diskette. Kit contains centering post, pressure
tool and tough 7 mil mylar reinforcing rings for
25 diskettes.
5, Kit $14.95
5", Rings only $7.95
8". Kit $16.95
', Rings only SB. 95
The CP/M HANDBOOK (with MP/M) by Rod-
nay Zaks $13.95
PASCAL USER MANUAL AND REPORT-By
Jensen and Wirth. The standard textbook on
the language. Recommended for use by
Pascal/Z, Pascal/M and Pascal/MT users $12
THE C PROGRAMMING LANGUAGE- By
Kernighan and Ritchie. The standard textbook
on the language. Recommended for use by
BDS C, tiny C. and Whitesmiths C users . .$12
STRUCTURED MICROPROCESSOR PRO-
GRAMMING- By the authors of SMAL/80.
Covers structured programming, the 8080/
8085 instruction set and the SMAL/80 lan-
guage $20
ACCOUNTS PAYABLE & ACCOUNTS
RECEIVABLE- CBASIC book by Osborne/
McGraw-Hill $20
GENERAL LEDGER - CBASIC book by
Osborne/McGraw-Hill $20
PAYROLL WITH COST ACCOUNTING-
CBASIC book by Osborne/McGraw-Hill . .$20
• **•••**
* Program names trademarked
f Recommended system configuration consists
of 48K CP/M, 2 full size disk drives, 24 x 80 CRT
and 132 column printer.
® Modified version available for use with CP/M as
implemented on Heath and TRS-80 Model I
computers.
©User license agreement for this product must
be signed and returned to Lifeboat Associates
before shipment may be made.
©This product Includes/eXcludes the language
©manual recommended in Condiments.
©Serial number of CP/M system must be
supplied with orders.
©Requires Z80 CPU.
**•*•***
Ordering Information
MEDIA FORMAT ORDERING CODES.
When ordering, please specify format code.
LIFEBOAT ASSOCIATES MEDIA FORMATS LIST. Diskette, cartridge disk and cartridge tape
format codes to be specified when ordering software for listed computer or disk systems. All
software products have specific requirements in terms of hardware or software support, such as
MPU type, memory size, support operating system or language.
Computer lyiiim Format Coda
Alialr BSOODiSk . . . See MITS 3200
Alios AT
Apple - ScftCard 13 Sector , , . ,RG
Apple + SoftCard 1 6 Seclor . , . .RR
AVL Eagle RB
BASF Syslem 7100 RD
Blackhawk Single Density 03
Blackhawk Micropenis Mod II 03
CDS Versatile 3B Ql
CDS Versatile 4 Q2
COMPAL-80 Q2
Cromemco System 3 Ar
Cromemco Z2D R6
CSSN BACKUP (lape) T1#
Delia AT
Dlgl-Log Mlcroterm II RD
Digital Microsystems Ar
Discus See Morrow Discus
Ourango F-85 RL
Dyiabyte DBB/2 R1
Dynabyte DB8/4 A1*
Exldy Sorcerer h Lifeboat CP/M .02
Exidy Sorcerer - Exldy CP/M , . .04
Heath HB - H17/H27 P4
Heath H89 - Lifeboat CP/M . . . .P4
Haalh HB9 - Magnolia CP/M . . .P7
Hallos II ,See Processor Technology
Horizon See Norlh Star
ICOM 2411 Microfloppy R3
iCOM 3712 A1
ICOM 3B12 AT
Prices reflect distribution on 8'
single density diskettes. If a
format is requested which
requires additional diskettes, a
surcharge of SB. per additional
diskette will be added.
Prices FO.B. New York,
Shipping, handling and C.O.D.
charges extra,
Manual cost applicable against
price of subsequent software
purchase.
The sale of each proprietary
software package conveys a
license for use on one
3m only.
Computer ayaiem For mat Cod a
ICOM 4511 5440 Cartridge
CP/M 1.4 D1#
ICOM 4511 5440 Cartridge
CP/M 2.2 D2#
IMS 5000 RA
IMS 8000 AT
IMSAI VDP-40 R4"
IMSAI VDP-42 R4"
IMSAI VDP-44 R5"
IMSAI VDP-60 AT"
Intecolor See ISC Intecolor
Intel MDS Single Density A2
Intel MDS Double Density A5
Interlec SuperBraln DOS 0.1 ... R7
Inlertec SuperBraln DOS 0.5-2. X RJ
Inlertec SuperBraln DOS 3.X RK
ISC Intecolor 6063/8360/B963 . ,A1
Konlron PSI-80 RF
Meca5'/<" P6
Mlcromallon
(Except TRS-80 below) AT
MicropoliS Mod I Ql
Micropolls Mod II 02
MITS 3200/3202 B1
Morrow Discus AT
Mostek A1
MSD5WT RC
North Star Single Density P1
North Star Double/Quad P2
Nylac Single Density 03
NylacMlcropollsMod.il 02
Oh'o Scientific C3 A3
OnyxCSOOl T2#
Pertec PCC 2000 AT
Processor Technology Helios II . .B2
Quay 500 RO
Quay 520 RP
RAIR Single Density R9
• Single-Side Single-Density disks
are supplied for use with Double-
Density and Double-Side 8 soft
seclor format systems.
" IMSAI formats are single density
with directory offset of zero.
# A media surcharge ol 525 (or or-
ders on tape formats Tl and T2 and
ol S100 for orders on disk lormats
D1 and D2 will be added.
The list of available formats Is sub-
ject to change withoul notice. In
case of uncertainty, call to confirm
the lormat code lor any particular
equipment.
Computer ayitem Formal CoOa
RAIR Double Density RE
Research Machines 8 A1
Research Machines 5Vi" RH
REX 03
Sanco7000 5'/i" RQ
SD Systems 8' AT
SO Systems 5'/*" R3
Sorcerer See Exidy Sorcerer
Spacebyle Ai
SuperBraln See Interlec
Tarbell AT
Tfittt" R3
TEI 8 AT
Thlnkertoys See Morrow Discus
TRS-80 Model I 5 'A" R2
TRS-80 Model I - FEC Freedom RN
TRS-80 Model I - Mlcromallon . .A4"
TRS-80 Model I -r Omlkron 5V*" .RM
TRS-80 Model I 4 Omlkron 8" . . .A1
TRS-80 Model I - ShuflleboardB" A1
TRS-80 Model II AT
VDP-40/42/44/80 See IMSAI
Vector Graphic Q2
Vector MZ Q2
Versatile See CDS Versatile
Vista V8D 5V* Single Density . . . .P5
Vista V200 BVSt* DoublB Density . ,P6
Zenith Z69 • Lifeboat CP/M ...,P4
Zenith ZB9 - Magnolia CP/M . . .P7
Lifeboat ASSOCiateS, 1651 Third Avenue, N.Y, N.Y 10028 (212)860-0300 ™The Software Supermarket is a trademark
International Telex: 220501 , Domestic Telex: 640693 of L,feboat Assoc,ates
<aa* For The
$ 99 GENERAL
The Micro Computer General 85
OEM Industry
University
FOR USE IN:
° Laboratory
Home
The General is a 4.5" x 6" single board micro
computer, ideal for industrial control applications
as well as for dedicated test monitoring systems,
communication subsystems, small scale data
processing and front end processing. Through its
advanced design, it is adaptable for data logging,
data acquisition, prototyping and experimenting.
Program development is facilitated through the
General's "Expeditor" system monitor. The Ex-
peditor has specialized commands for automatic
baud rate selection — uploading and download-
ing which speed up development and cut down on
"hidden" program costs. An optional assembler
and disassembler on a 2716 will compliment the
Expeditor and will further reduce programming
time and cost.
The General comes complete with the Deluxe
Users Manual which offers complete instructions
on hardware and software usage.
THE GENERAL — ONE POWERFUL
COMPUTER SYSTEM
HARDWARE FEATURES
Board dimensions — 4.5" x 6"
8085 A CPU
4 Level programmable Interrupt
3 Priority Interrupts
2 Non-maskable Interrupts
256 Bytes of programmable memory
(expandable on board to 2 K bytes of
either Static Ram or CMOS Ram with
battery back-up)
2 K Bytes of EPROM — expandable
on board to 4 K bytes
22 Programmable parallel I/O lines
(ports)
6 Bit memory mapped port
Programmable 14 bit binary counter
and timer controlled through the
system software
Software compatible with the 8080
THE GENERAL MCG-85 $99.00
(Kit)
The GENERAL MCG-85 $135.00
(Assembled & Tested)
2 K Expansion Rom
SOFTWARE FEATURES
EXPEDITOR — 2 K SYSTEM MONITOR
Automatic Baud Rate
Selection (50-9600 Baud)
° Downloading — from a computer that
supports an assembler. This will enable
the user to develop programs on a time
sharing service, a larger computer, and
download directly to the Ram of the
General.
° Uploading — Develop programs on the
General and upload them to a computer
that supports a disk drive for program
storage.
Hex Keypad and Display $69.00
2 K Basic in Rom $59.00
$30.00
2 K Assembler &
Disassembler $40.00
2 K Expansion Ram $30.00 Expeditor Monitor Listings $29.00
(Manual Form)
2 weeks to clear) or charge to Visa or Master
add 8% sales tax.
Send certified check (regular checks require
Card. Add $3.00 shipping. N.Y. residents
L
* In Kit form, single quantity, introductory offer.
Dealer Inquiries Invited
ATLANTIS COMPUTERS
Division of
Atlantis Computerized Services
34-13 30 Ave. Astoria, NY 11103
(212) 728-6700
Desk-Top Wonders
Self-Modifying Code
for the TI-58/59
Ted Green, Box 2289- AMR
Johns Hopkins University
Charles and 34th St
Baltimore MD 21218
Because of the four multiregister memories in the Texas
Instruments TI-59 programmable calculator and their
ability to hold either data or program steps, it is possible
to let the TI-59 change its set of instructions, or any seg-
ment of its instructions, at any time during the program.
This is done by "overlapping" data registers and program
steps.
To see how the TI-59 stores numbers contained in the
data register in the program-step memory, enter the
following, repartitioning to 100 data memories, steps:
1234567891
ST0 99
Op 17
GTO 000
LRN
Examine the LRN mode using SST; keep in mind that
originally there was nothing in the LRN mode. Now, we
examine the following locations:
000 90
001 00
002 00
003 91
004 78
005 56
006 34
007 12
The code in location 000 represents the type of number
that was entered. In this case, the 9 stands for a number
that consumed 9 memory locations (location 007 repre-
sents memory location 1, location 6 represents memory
locations 2 and 3, location 5 is for memory locations 4
and 5, etc). Notice that the number entered as
1234567891 is stored as 9178563412 (starting at location
003). The empty registers 001 and 002 are used for the
storage of up to thirteen digits (in location 001, the
rightmost digit is always 0). If you entered 1234567891
and stored it in data register 98, your LRN mode would
look like this:
000 00
008 90
001 00
009 00
002 00
010 00
003 00
011 91
004 00
012 78
005 00
013 56
006 00
014 34
007 00
015 12
142 January 1981 © BYTE Publications lnc
Circle 90 on inquiry card.
Circle 91 on inquiry card.
New on the North Star Horizon:
18Mb Hard Disk Drive!
r i
o
I I
L
.^fl
Horizon Computer with 64K RAM
and dual quad capacity (720kb)
floppy disks
Up to four 18Mb Winchester-
type hard disk drives
Display terminal
Letter-quality or dot
matrix printer
Horizon I/O flexibility
allows expansion to
meet your needs
Unsurpassed Performance and Capacity!
North Star now gives you hard disk capacity and process-
ing performance never before possible at such a low
price! Horizon is a proven, reliable, affordable computer
system with unique hardware and software. Now the
Horizon's capabilities are expanded to meet your growing
system requirements. In addition to hard disk perform-
ance, the Horizon has I/O versatility and an optional hard-
ware floating point board for high-performance number
crunching. The North Star large disk is a Century Data
Marksman, a Winchester-type drive that holds 18 million
bytes of formatted data. The North Star controller inter-
faces the drive(s) to the Horizon and takes full advantage
NorthStaf^
North Star Computers, Inc.
1440 Fourth St.
Berkeley, CA 94710
(415) 527-6950 TWX/Telex 910-366-7001
of the high-performance characteristics of the drive. Our
hard disk operating system implements a powerful file
system as well as backup and recovery on floppy diskette.
Software Is The Key!
The Horizon's success to date has been built on the qual-
ity of its system software (BASIC, DOS, PASCAL) and
the very broad range and availability of application soft-
ware. This reputation continues with our new hard disk
system. Existing software is upward compatible for use
with the hard disk system. And, with the dramatic increase
in on-line storage and speed, there will be a continually
expanding library of readily available application software.
For more information, see your North Star dealer!
HORIZON-HD-18
Horizon computer with 64K
RAM, 2 quad capacity mini
drives and one HDS-18 hard
disk drive $9329
HDS-18
Additional 18Mb hard disk drive
for expansion of Horizon HD-18,
or your present Horizon $4999
SYS-1N
Complete Horizon HD-18 plus
80 x 24 display terminal and
NEC Spinwriter printer $13,239
SYS-1A
Complete Horizon HD-18 with
80 x 24 display terminal and
Anadex printer $11,319
Desk- Top Wonders.
Storing the same number in data register 97 would use
memory locations 016 thru 023, and so on. This scheme
continues throughout, with data register 00 taking up
memory locations 952 thru 959.
To apply this principle, try the following example:
9
Op 17
8166950185
+
.686
ST0 99
Op 17
RST
Now examine the LRN mode and notice the following:
000 90 List
001 60 Deg
002 68 Nop
003 85 +
004 01 1
005 95 =
006 66 Pause
007 81 RST
This is a counting program. Press RST, R/S, 1 . . . 2 . . .
3 . . . 4 . . . etc. The .686 was added because neither the
Deg nor the Nop have any effect on numbers that are
"carried" from one step to another.
There are drawbacks to this storage system. For in-
stance, if the number 1 is stored in memory 99, all pro-
gram locations 001 thru 006 are cleared, erasing every-
thing between 000 and 007. Also, the instruction 000 90
appears to be troublesome and cannot be changed to a
useful code; all it does is take up space. In addition, the
code in 002 always has a on the rightmost side, which
disables the code. Keep in mind that this also applies to
codes 008 and 009, 017 and 018, all the way up through
952 and 953.
Listing 1 is an actual program that will first begin as a
counting program, then, after adding 1, it will modify its
instructions so that it becomes a subtraction program. ■
Listing 1: A demonstration program showing self-modifying
code on the Texas Instruments TI-58 or Tl-59 programmable
calculators. When run, the program adds 1 to the number on the
display, then continually subtracts until R/S is pressed. Begin
execution at step 950. As soon as the program begins, hold
down the Pause key to see the program work. After the pro-
gram has been run, examine the LRN mode to observe how the
code has been modified.
Step
Code
Key
000
76
Lbl
001
12
B
002
05
5
003
69
Op
004
17
17
005
01
1
006
01
1
007
06
6
008
01
1
009
09
9
010
05
5
011
00
012
01
1
013
07
7
014
05
5
015
85
+
016
93
017
06
6
018
08
8
019
06
6
020
95
=
021
42
STO
022
00
00
023
00
00
024
69
Op
025
17
17
026
61
GTO
027
09
949
028
49
—
949
32
xgt
950
76
Lbl
951
11
A
952
85
+
953
01
1
954
95
=
955
32
xgt
956
61
GTO
957
12
B
* NORTH STAR USERS *
8" FLOPPY SUBSYSTEM HAS DAWNED ON THE HORIZO
COMPLETE WITH MANUALS. SOFTWARE, HARDWARE FULLY INTEGRATED, READY TO RUN
v Totally compatible with North Star hardware * Allows use of 8' and/or 5" drives * Detailed, 80 page manual included * Background print tasks
* Supports Hoppy files up to 4.2 MB * Simple, plug-in operation * Fully CP/M" compatible *File security * Extensive utilities included
DMA-DOS Software S200
Dynamic Microprocess Associates Disk Operating System
Tarbell Double Density Controller $420
Cables $40
Dual Shugart 8" 800R drives in cabinet with fan
and power supply $1,250
Total package $1,910
Prices antl offers subject to change without notice
n WE WILL PAY SHIPPING ON PREPAID ORDERS (Continental USA only). WE HAVE NO READER INQUIRY NUMBER. PLEASE WRITE OR CALL.
JOHN D. OWENS ASSOCIATES, INC.
12 SCHUBERT STREET, STATEN ISLAND, NEW YORK 10305
OVERSEAS CALLERS: TWX 710 588 2844 or call (212) 448 6298*DOMESTIC CALLS: (212) 448 6283 (212) 448 6298 (212) 448 2913
144 January 1981 © BYTE Publications Inc
baZic is written entirely in Z80 5 code — baZic runs as much
as 30% faster than North Star 8 BASIC. The greater execu-
tion speed is significandy advantageous for hea\y number
crunching, multiuser and multitasking operations.
baZic has all the features of North Star BASIC — and
then some.baZic, with minor exceptions, is 100% compatible
with existing North Star BASIC programs. Our new baZic
s under all Micro Mike's timesharing and hard disk
rating software, including JOEDOS/.IOESHARE/
SHARE and 5SHARE.
CHECK THESE FEATURES AT YOUR
COMPUTER DEALER:
■ lakes full advantage of the Z80 instruction set
■ Can be used on any Z80-based microcomputer operating
under North Star DOS or CP/M* (CP/M versions available
early '81)
■ Supports North Star floating point board for even faster
execution of compute intensive programs
■ Makes Multiuser systems with floppy disks more practical
■ Improves performance of Multiuser Hard Disk systems
■ baZic adds functions to assist in screen formatting, as well as
features to simplify programming, e.g. APPEND command/
statement, ON GOSUB, cursor-addressable PRINT, etc.
■ baZic, as shipped, includes 8, 10, 12 and 14 digit precisions,
including both software and hardware floating point versions
■ baZic is now included with Micro Mike's operating system
software and applications programs
Dealers and OEM's: Special Discounts Available
For complete information, contact your North Star dealer or
send $1 to Micro Mike's for complete technical presentation.
"North Star Computers, Inc.
"Zilog, Inc.
"Digital Research, Inc.
Micro Mike's Inc.
905 S. Buchanan, Amarillo, Texas 79101
806-372-3633
Circle 92 on inquiry card.
Hard fact:
$150 package makes your Horizon
execute programs up to 30% faster!
: at**.
m
;*%
>. W
The Model-Ill is a completely self-contained
desk-top unit. Like the Model-I it is fully ex-
pandable. There's plenty of room inside for
more memory, communications interface,
and 2 double-density disk drives. And best of
all many of the programs now available for
the Model-I will run on the Model-Ill. HARD-
SIDE's low price includes shipping charges
and our extended 180-day warranty. Model-Ill
W/16K RAM $929.00
TRS-80 goes color! This is a complete, all-
around personal computer. Instant-load Pro-
gram Paks cover a wide range. The Color
Computer offers vivid color graphics for ex-
citing visual displays. The Color Computer
attaches easily to any color TV. It programs
easily in Color BASIC or the more powerful
Extended Color BASIC. More expansions,
even disk storage, will be available soon.
HARDSIDE's low price includes shipping
charges and our extended 180-day warranty.
TRSSO COLOR COMPUTER w/4K RAM $359.00
Model-ll,64KRAM
LIST PRICE
$3899.00
$999.00
$2495.00
$298.95
$599.00
$179.95
$279.95
$349.95
$418.00
$537.00
$99.00
$119.00
$119.00
$59.00
OUR PRICE
$3799 00
Model-Ill, 16KRAM
$929 00
Model-Ill, 32K Dual Disk
Pocket Computer w/ Interface. . . .
TRS-80 Color Computer Expanded
COMM-80 Interlace
$2299.00
$269.00
$519.00
$159.95
CHATTER BOX Interface
DISK-80 Interface
$259.95
$329 95
Expansion Interface, 16K RAM . . .
Expansion Interface, 32K RAM . . .
RS-232-C Board
$339.00
$399.00
$89.00
TRS-232 Printer Interface
16K Memory Kit, TRS-Keypad . . .
16K Memory Kit, TRS-Exp. Int. ..
Upper/lower Mod Kit
$59.95
$59.00
$59.00
$24.95
Video Reverse Kit
LIST PRICE
$9.95
$109.00
$84.00
$429.95
$849.00
$399.95
$675.00
$399.00
$29.95
$39.95
OUR PRICE
$23.95
CPU Speed-up Kit
Percom Electric Crayon, w/cable .
TRS-80 Dust Cover (3pc set)
TRS-80 Computer Case
TRS-80 Monitor Case
$34.95
$279.95
$7.95
$99.95
$84.00
Percom, TFD-100, 40-track
Percom, Dual TFD-100 Drives
Percom, TFD-40, 40-track
Percom, TFD-200, 77-track
Hardside, 40-track Disk Drive . . .
Percom Doubler
$399.00
$799.00
$379.00
$629.00
$359.00
$129.95
Percom Data Separator
$29.95
2-Drive Cable
$29.00
4-Drive Cable
$39.00
TERMS'. Prices and specifications are subject to change. HARDSIDE accepts VISA & MASTERCARD.
Certified checks and Money Orders; Personal checks accepted (takes 3 weeks to clear). HARDSIDE pays
all shipping charges (within the 48 states) on all PREPAID orders OVER $100. On all orders under $100 a
$2.50 handling charge must be added. COD orders accepted (orders over $250 require 25% deposit) there is
a $5.00 handling charge. UPS, Blue Label, and Air Freight available at extra cost.
TOLL FREE ORDERS:
1-800-258-1790
6 South St., Mllford, NH 03055
(In NH call 673-5144)
TS£:HPIRDSID€
146 BYTE January 1981
Circle 93 on inquiry card.
1 I
under one roof!
At TSE HARDSIDE we stock our shelves with only the finest products
available to make your micro-merchandise shopping a pleasure. So the
next time you're considering a purchase for your micro, just pick up the
telephone and dial our toll-free number 1-800-258-1790 (in NH call 673-5144)
to get in touch with all that counts in the micro industry.
SOFTWARE
Microsoft
Apparat
Racet
Hayden
Muse
Creative Computing
Personal Software
Scott Adams
Acorn Software
Synergistics
Strategic Simulations
Lance Micklus
Softape
Quality Software
Web Associates
Small System Software
Image
On-Line Systems
Ritam
Avalon Hill
Big Five
Micro Lab
Programmers Guild
Quality Software Distributors
HARDWARE
• Radio Shack
• Commodore Pet
• Atari
• Percom
• Centronics
• NEC
• Sun
• Okidata
• Source/Telecomputing
• Computer Case Co.
• MicroMint
• Eaton LRC
• Cover Craft
• BSR
• BASF
• Corvus
• Archbold Electronics
• ESP
• Novation
BOOKS
• Hayden
• Wiley
• Scelbi
• Compusoft
• Dilithium
• Sams
• Radio Shack
• SoftSide
• Addison Wesley
• Computer Science Press
• Rainbow Associates
• Plus much more!
Send S1.00 for our catalog, and receive a
$2.00 credit toward your next purchase.
TStdHflRDSirX
6 South St., Mllford, NH 03055 (603) 673-5144
Circle 94 on inquiry card.
Generating Bar Code
in the Hewlett-Packard Format
The HP-41C is Hewlett-Packard's
newest entry in the hand-held pro-
grammable calculator race. The main
feature that distinguishes it from
Hewlett-Packard's earlier calculators
is its modular design, which allows
the HP-41C to be extended by a line
of peripheral devices. Up to four
peripherals can be plugged into the
calculator, and these include a
magnetic card reader, a thermal
printer, memory modules to increase
the amount of memory available to
the user, and "application pacs" that
contain software for particular ap-
plications in read-only-memory
module form. In addition, Hewlett-
Packard has introduced the 82153A
Optical Reader (also called a Wand),
which is capable of reading bar codes
that contain HP-41C programs, data,
or function definitions.
This article describes the HP-41C
bar-code format and includes a
BASIC program that converts an HP-
41C program into a series of bar-code
rows that can be printed using a high-
quality printer with incremental spac-
ing.
HP-41C Bar-Code Format
The bar code that is read by the
Wand is simply binary information
represented by wide and narrow bars
(representing 1 and 0, respectively).
The space- 'between each bar is
nominally the width of the narrow
bar and serves as a benchmark for the
current unit bar width. The unit bar
width must be greater than 15 mils. A
narrow bar may be up to 20% wider
than the unit bar width, which is
Thomas McNeal
Hewlett-Packard
Cupertino Integrated Circuits Operation
10900 Wolfe Rd
Cupertino CA 95014
established by the previous bar and
space. A wide bar should be twice the
unit bar width, and a wide bar should
vary no more than 20% from its stan-
dard value.
The bars are logically grouped into
8-bit bytes, and a bar-code program
is organized into rows of a maximum
of 16 bytes, with 3 bytes of header
information and up to 13 bytes of
data per row. Associated with each
row are pairs of start and stop bits
(binary 00 and 10, respectively) that
allow the rows to be read in either
direction. Figure 1 shows the format
for a single row of program bar code.
The 13 data bytes contain the ma-
chine language of the HP-41C instruc-
tion set. Table 1 lists these instruc-
tions, with the first 8-bit byte of each
instruction determining the instruc-
tion type. Additional bytes, if any,
contain alphanumeric character data,
numeric or stack operands, or linkage
information.
All indirect instructions are 2 bytes
long, with the high-order bit of the
second byte set to 1 to signify an in-
direct operand. In the case of indirect
numeric GOTO and EXECUTE in-
structions, the high-order bit is set to
1 for an EXECUTE instruction and
cleared to for a GOTO instruction.
The size of an instruction is deter-
mined by its position in the table. In
order to save room in the HP-41C,
some instructions may have two com-
pletely different representations, de-
pending on the value of the operand
associated with that instruction. For
example, the numeric label instruc-
tion is represented by 1 byte if the
operand is less than 15 and, other-
wise, by 2 bytes. The XROM (EXE-
CUTE read-only -memory module) in-
structions seen in the function table
also save room when a reference to an
alpha label within a read-only-mem-
ory module is made by an EXECUTE
instruction. The XROM instruction is
a compact, 2-byte reference to a table
of alphanumeric labels within the
read-only-memory module; this re-
places the EXECUTE instruction orig-
inally entered by the user.
HP-41C Internal Representation
The instructions generally are 1, 2,
or 3 bytes long, with the 4 high-order
bits of the first byte indicating the in-
struction length. The exceptions to
this rule are the instructions contain-
ing alphanumeric character data. The
HP-41C has an alphanumeric display
that allows the definition of instruc-
tions with nonnumeric operands.
These functions include an alpha-
numeric label instruction, which con-
tains a label of up to seven characters,
GOTO and EXECUTE instructions
with alphanumeric label operands,
and a text-entry instruction. This last
instruction will either append or re-
place character data in a special
alphanumeric register and may con-
tain up to fifteen characters.
All character data is represented in
ASCII (American Standard Code for
Information Interchange), with one
character per byte and a few excep-
tions for special characters not found
in the ASCII character set. Since
character-oriented instructions are of
indeterminate length, their size is
148 January 1981 © BYTE Publications Inc
Please send your free software catalog.
(Check which software is of particular interest)
D C COMPILER. Optimized native code for VAX 11/780, PDP-11, LSI-11, Z80,
8085, 8080. Full C language as defined in Kernighan and Ritchie, with com-
prehensive portable library. Cross compilers available. Runs under VMS,
IAS, RSX-11D, RSX-11M, RSTS/E, RT-11, UNIX, Idris, CDOS, CP/M. From $600
□ IDRIS OPERATING SYSTEM. System calls and file system identical to
UNIX V6, including pipelines. Utilities include shell, editor, assembler,
loader, archiver, compare, copy, grep, etc., plus system utilities for file
system maintenance. Runs on LSI-11, PDP-11. From $1000.
□ PASCAL COMPILER. Optimized native code for VAX 11/780, PDP-11,
LSI-11, Z80, 8085, 8080. Full Pascal language as defined in Jensen and
Wirth, with standard library. Includes C compiler and portable library,
permitting intermixed C and Pascal. Cross compilers available. Runs
under VMS, IAS, RSX-11D, RSX-11M, RSTS/E, RT-11, UNIX, Idris, CDOS,
CP/M. From $750.
Name_
Company.
Street
City
_State_
-Zip_
Idris is a trademark of Whitesmiths Ltd.
UNIX is a trademark of Bell Laboratories.
CP/M is a trademark of Digital Research Co.
VMS. RSX-11. RT-11, RSTS/E. VAX,
PDP-11. LSI-11 are trademarks of Digital
Equipment Corporalion.
Whitesmiths, Ltd.
Software for grownups.
(212)799-1200 ° r
RO.B. 1132 Ansonia Station, New York, N.Y. 10023
VALUE
FUNCTION
NUMBER
OF BITS
nnnnnnnn
nnnn
(UP TO 13 BYTES )-
• I nnnn
J
10
START
BITS
CHECKSUM
SEQUENCE
NUMBER
LEADING
PARTIAL
FCN BYTES
DATA
(TRAILING
I PARTIAL
I FCN BYTES
STOP
BITS
UP TO 104
Figure 1: Format for Hewlett-Packard bar codes. A maximum of 13 bytes can be encoded into one row of bar code.
embedded within a word in the in-
struction itself. For alphanumeric
label operands, the number of char-
acters is held in the 4 low-order bits of
the second or third byte, with the 4
high-order bits set to hexadecimal F.
The position of this byte is indicated
in the documentation of the compile
routine of the bar-code generating
program. (See listing 1.) This conven-
tion allows differentiation between an
alphanumeric label instruction and an
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Overland Park, ATS (913) 492-4333 MD.: Wheaton, Brimberg Sales Assoc. (301) 946-2670; Baltimore, Brimberg
Sales Assoc. (301) 792-8661 MASS.: Waltham, Digital Sales Assoc. (617) 899-4300 MICH.: Southfield, L.H.
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end instruction, in which the third
word contains a hexadecimal F in the
low rather than the high 4 bits.
In addition, the alphanumeric label
and end instructions contain pointers
that link them with other alpha-
numeric label and end instructions,
creating an alphanumeric label chain.
This chain is used to identify the posi-
tion of labels and program bound-
aries within the HP-41C program
memory and establishes entry points
for each program. The chain is re-
compiled by the Wand software, so
the bytes containing the chain point-
ers are set to by this program.
For a detailed discussion of the
function table and other internal fea-
tures of the HP-41C, refer to a series
of articles that appeared in the Cor-
vallis Division Column of the PCC
Journal beginning on September 6,
1979. The PPC Journal is a publica-
tion of the PPC (Personal Program-
mable Calculator), an independent
user group for Hewlett-Packard pro-
grammable calculators. Further infor-
mation may be obtained by writing
to:
Richard Nelson, Editor
PPC Journal
2541 W Camden PI
Santa Ana CA 92704
The header information necessary
for a bar-code program is contained
in the left-most 3 bytes of each bar
code row. The first byte is a parity
check in the form of a running check-
sum (a summation modulo 256, with
wrap-around carry, of the checksum
of the preceding row and all other
bytes of the current row).
The second byte is split into two
parts. The 4 high-order bits contain
the program type (l=nonprivate,
2 = private), and the 4 low-order bits
contain the sequence number, which
is the bar-code row number minus 1,
modulo 16. The sequence number
will be inspected by the Wand soft-
ware to assure that the correct row is
being read.
Text continued on page 172
Circle 96 on inquiry card. — j
THE FRONT RUNNER
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GRAPHIC 280 XN DOT MATRIX. ! i PRINT SPEED TO 240 LINES PER MINUTE.
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SPRINTER 40 is a highly reliable printer/plotter providing long life-expectancy
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DISTRIBUTORS:
1 202 Eastchester Dr.
2 1 5 Park Ave. South
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(919) 883-9125
|212) 677-8400
Tel. |415) 968-1080
Tel. (714) 528-4480
Tel. (617) 862-8230
LOW ORDER 4 BITS
1
2
3 4
5
6 7
o
NULL
LBLOO
LBL01
LBL 02 LBL 03
LBL 04
LBL 05 LBL06~>
_
digit
1
2
3 4
5
6 7
CM
RCLOO
RCL 01
RCL 02
RCL 03 RCL 04
RCL 05
RCL 06 RCL 07
STO00
+
STO01
STO 02
*
STO 03 STO 04
/ X<Y?
STO 05
X>Y?
STO 06 STO 07
X<=Y? £ +
' BYTE
1 4 BITS
6 5
LN
X 2
SORT
Y* CHS
e*
LOG 10*
1/X
ABS
FACT
X*0? X>0?
LN(1 +X)
X<0? X = 0?
LU
CL
XoY
PI
CLST Rt
RDN
LASTX CLX
O
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DEG
RAD
GRAD
ENTERt STOP
RTN
BEEP CLA .>
CD
x »
RCL nn
STO nn
ST+ nn
ST- nn ST* nn
ST/nn
ISG nn DSE nn~
L
<
m
XROM
XROM
GTO 00
XROM
GTO 01
XROM XROM
GTO 02 GTO 03
XROM
GTO 04
XROM XROM
GTO 05 GTO 06
t 2
/ BYTES
.->
o
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BYTES
J
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TEXT
1
TEXT
2
TEXT TEXT
3 4
TEXT
5
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6 7 J
UP
TO 16
BYTES
Table 1: /I fnb/e /or the HP-41C instruction set.
Instructions in the HP-41C are
stored as one
or more 8-bit bytes.
Table 1 continued or
page 154.
Combine accurate flight characteristics with the best in animation graphics
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Computer and aviation experts call the
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Special Features:
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• Keyboard or joystick input
$
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for the Apple II
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$
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50
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Present cassette users may
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and receive the disk version.
See your dealer or order direct. For v^
direct order, include $1.25 and specify ^ — •
UPS or first class mail. Illinois residents
add 5% sales tax. Visa and Mastercard
accepted.
HflfeLOGIC
Distribution Corp.
Box V, Savoy, I L 61 874
(217)359-8482
152 January 1981 © BYTE Publications Inc
Circle 97 on inquiry card.
Free software ($50-$120 worth)
when you buy aTI programmable.
R.E.
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Printer
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59 Fun
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Electronic
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MODULE
POOL
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Civil
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Programming
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□ $10
Statistical
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□ $10
An $io
2 FREE modules, 2 FREE
Pakettes with a TI-59.
1 FREE module, 1 FREE Pakette
with a ; !
TI-58C. RSL'
□ $10 •
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Solid State Software™ modules
and Pakettes can help you utilize
the full capability of your TI
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Modules turn a programmable into
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have selected programs you key in.
The TI-58C. An exceptional value
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Up to 480 program steps or 60 mem-
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The TI-59. Top-of-the-line.
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□ I've bought a TI-59. Send me the 2 modules and 2
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MODULE 1 PAKETTE 1:
MODULE 2: PAKETTE 2:
"b!
Name
Address
Cily
State
Zip
ALTERNATE MODULE:
Send to: Texas Instruments Free Software Offer
P.O. Box 725, Dept. M, Lubbock, Texas 79491 Calculator Serial Number (from back of unit)
Return this coupon with (1) Customer Information Card (packed with calculator). (2) Dated copy ol prool of purchase between
January 15, 1981-March 31. 1981 Items must be postmarked by April 14. 1981. Please allow 30 days lor delivery Otter void where
prohibited Otter good only in U.S.A. TI reserves the right to substitute items
U.S. sug^esterl retail prices. *For use with TI-59 only.
Texas Instruments
) 1981 Texas Instruments Incorporated
NCORPOR ATED
J
45746
Circle 98 on Inquiry card.
Table 1 continued
LOW-ORDER 4 BITS
8
9
A
B
C
D
E
F
o
LBL07
LBL08
LBL09
LBL 10
LBL 11
LBL 12
LBL 13
LBL 14 "N
,-
8
9
.
EEX
(digit entry)
CHS
GTOa
XEQa
CM
RCL08
RCL09
RCL 10
RCL 11
RCL 12
RCL 13
RCL 14
RCL 15
CO
STO 08
STO 09
STO 10
STO 11
STO 12
STO 13
STO 14
STO 15
1
■■3-
E-
HMS +
HMS-
MOD
%
%CH
P-R
R-P ( BYTE
CO
e v -1
SIN
COS
TAN
ASIN
ACOS
ATAN
DEC
* CO
INT
FRAC
D-R
R-D
HMS
HR
RND
OCT
LU
Q r-
X = Y?
X*Y?
SIGN
X< =0?
MEAN
SDEV
AVIEW
CLD
O
x m
ASHF
PSE
CLRG
AOFF
AON
OFF
PROMPT
ADV J
X m
VIEW nn
REG nn
ASTO nn
ARCL nn
FIXn
SCI n
ENGn
TONEn-^
<
SF nn
CF nn
FS?C nn
FC?C nn
FS? nn
FC? nn
GTO/XEO
IND
I
I 2
m
GTO07
GTO 08
GTO 09
GTO 10
GTO 11
GTO 12
GTO 13
GTO 14
' BYTES
o
— »-X< >nn
LBL nn -^
Q
— :)
3
BYTES
TEXT
TEXT
TEXT
TEXT
TEXT
TEXT
TEXT
TEXT "\
UP
LL
8
9
10
11
12
13
14
15 j
TO 16
BYTES
Quiet Designs
Preformatted Disks:
Compatible with Lanier 'No Problem',
Lanier 90/100, Micom 2000/2001,
A.M. 425, C.P.T. 6000/8000, Canon
Standard Disks
For all systems using unformatted disks
Head Cleaning Kits
Kits for 5'/4" and 8" drives
Flip-Sort™
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and Retrieval System.
Quiet Designs
Quiet Designs Inc.
1330 W. Robinhood Dr.,
Suite F
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Ph. (209) 957-8631
Quiet Designs Inc.
473 Macara #706
Sunnyvale, CA 94086
Ph. (408) 739-5215
Quiet Designs of California
1030 W. Maude #51 2
Sunnyvale, CA 94086
Ph. (408) 730-0170
Quiet Designs International
5940 F #2 Road
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Canada V7C 4R9
Ph. (604) 273-9710
154 January 1981 © BYTE Publications Inc
Circle 99 on inquiry card.
^a
BASIC SOFTWARE LIBRARY
NOW * 10 * Volumes and Growing
WHY Pay hundreds of dollars for Software that does Not work when WE offer the BEST
available Software for only a few dollars a program. And what is better OURS WORKS!
We have over 100,000 in circulation since 1975 and we are still around and That's more than Anyone else can say. We
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in Volume III for over $6,000 but a few years ago we decided to promote software to the mass public and it was an
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For Homeowners, Businessmen, Engineers, Hobbyists, Doctors, Lawyers, Men and Women
Vol. 1 $24.95
Vol. II $24.95
Business &
Animals Four
Binomial
Beam
Personal
Astronaut
Chi-Sq.
Conv.
Bookkeeping
Bagel
Coeft.
Filter
Programs
Bio Cycle
Confidence 1
Fit
Cannons
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Integration 1
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Correlations
Integration 2
Building
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Doglight
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Lola
Cyclic
Golf
Dual Plot
Macro
Decision 1
Judy
Exp-Distri
Max. Min
Decision 2
Line Up
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Roulette
Plot
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Rand 1
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Return 1
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Vector
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Nude
Schedule 1
Peace
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APPENDIX A
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Schedule 2
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Vol. VI
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Vol. IV
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Almost every single program
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OVER 116,
illli
USE TODAY
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156 January 1981 © BYTE Publications Inc
Why is the 88G Printer
the new industry
leader?
QUALITY
The attractive, durable 88G casework is
formed from impact-resistant, flame-
retardant Styron. Microprocessor con-
trolled stepper motors provide precision
control over print head and paper
positioning. Computer quality tractors
position paper for readability and are
fully adjustable to accommodate varying
paper widths.
MICROPROCESSOR
CONTROLLED INTERFACE
The microprocessor array provides the
intelligence for a dual RS232 serial
and a Centronics® type parallel interface.
Both inputs are fully buffered to allow
the 88G to receive data and print
simultaneously. A IK character buffer is
standard with a 2K buffer available as
an option.
The short line thruput of the 88G has
been increased by incorporation of a
Quick Cancel feature that fully utilizes
the bidirectional/unidirectional printing
capabilities. Built-in diagnostic and
self-test capabilities allow the user to
easily pinpoint system problems and
a Power On confidence
test verifies
operational status of
the printer each
time power is applied
VERSATILITY
The 88G prints a full upper and lower
case 96 character ASCII set with a crisp,
clear 7x7 matrix in 80, 96, or 132 column
formats. For text processing and
correspondence applications, an 11x7,
80 column serif style matrix can be
selected by switch or software command.
The dual tractor/pressure-feed paper
drive system allows the user to choose
either pin-feed, roll, or single sheet
papers up to 9.5 inches wide.
Complete forms control allows the
88G to be quickly configured for printing
single or multiple-ply invoices, purchase
orders, checks, or any type of preprinted
form. Optional paper roll holders and
single sheet feeders can be quickly
attached.
The wide use range of the 88G makes
it the perfect companion for business
systems, data processing, RO teleprinter
and terminal printer applications.
GRAPHICS
A high-resolution, dot-addressable
graphics option can be added for appli-
cations requiring plotting, printing of
screen graphics, drawings, illustrations,
etc. Single dot print resolution greatly
extends the usefulness of the graphics
capability. Selection of one of the
four horizontal dot densities available
customizes the graphic printout, and
alphanumerics can easily be included
for titling of graphs and illustrations.
LONG LIFE
RIBBON CARTRIDGE
Ribbon difficulties are minimized
through use of a continuous loop cart-
ridge with a five million character life.
It is easily changed without opening
the case, and without any complicated
or messy threading operations.
PRICE
Every detail is directed toward providing
a heavy-duty, commercial quality
printer for only $749.00. No other printer
on the market today can provide its
quality, features and performance at
a comparable price. The 88G is an
obvious industry leader.
^Centronics is a registered trademark of the Centronics Data Computer Corp.
Circle 100 on Inquiry card.
Micro Peripherals, Inc.
4426 South Century Drive
Salt Lake City, Utah 84107
Phone (801) 973-6053
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iT. iT. ij 1 . ij'.
158 January 1981 © BYTE Publications Inc
Circle 101 on inquiry card.
00MPUS1AR
INTERTEC S NEW $2500 MULTI-USER SMALL BUSINESS COMPUTER
At last, there's a multi-user micro-
computer system designed and built the
way it should be. The CompuStar™. Our
new, low-cost "shared-disk" multi-user
system with mainframe performance.
Unlike any other system, our new
CompuStar offers what we believe to be the
most practical approach to almost any
multi-user application. Data entry. Distrib-
uted processing. Small business. Scientific.
Whatever! And never before has such
powerful performance been available at
such modest cost. Here's how we did it . . .
The system architecture of the
CompuStar is based on four types of video
display terminals, each of which can be
connected into an auxiliary hard disk stor-
age system. Up to 255 terminals can be
connected into a single network! Each ter-
minal (called a Video Processing Unit) con-
tains its own microprocessor and 64K of
dynamic RAM. The result? Lightning fast
program execution! Even when all users
are on-line performing different tasks! A
special "multiplexor" in the CompuStar
Disk Storage System ties all exter-
nal users together to "share" the
system's disk resources. So, no
single user ever need wait on an-
other. An exciting concept . . .
with some awesome application
possibilities!
CompuStar™ user
stations can be configured in
almost as many ways as you
can imagine. The wide variety
of terminals offered gives you
the flexibility and versatility
you've always wanted (but
never had) in a multi-user
system. The CompuStar
Model 10 is a program-
mable, intelligent terminal
with 64K of RAM. It's a
real workhorse if your re-
quirement is a data entry
or inquiry/response application. And if your
terminal needs are more sophisticated,
select either the CompuStar Model 20, 30
or 40 Each can be used as either a stand-
alone workstation or tied into a multi-user
network. The Model 20 incorporates all of
the features of the Model 10 with the
addition of two, double-density mini-flop-
pies built right in. And it boasts over
350,000 bytes of local, off-line user stor-
age. The Model 30 also features a dual
drive system but offers over 700,000 bytes
of disk storage. And. the Model 40 boasts
nearly 1 % million bytes of dual disk stor-
age. But no matter which model you
select, you'll enjoy unparalleled versatility
in configuring your multi-user network.
Add as many terminals as you like
- at prices starting at less than $2500.
Now that's truly incredible!
No matter what your application,
the CompuStar can handle it! Three disk
storage options are available. A tabletop
10 megabyte 8" winchester-type drive
complete with power supply and our spe-
cial controller and multiplexor costs just
$4995. Or, if your disk storage needs are
more demanding, select either a 32 or 96
megabyte Control Data CMD drive with a
16 megabyte removable, top loading car-
tridge. Plus, there's no fuss in getting a
CompuStar system up and running. Just
plug in a Video Processing Unit and you're
ready to go . . . with up to 254 more ter-
minals in the network by simply connect-
ing them together in a "daisy-chain"
fashion. CompuStar's special parallel
interface allows for system cable lengths
of up to one mile . . . with data transfer
rates of 1.6 million BPS!
Software costs are low, too.
CompuStar's disk operating system is the
industry standard CP/M*. With an
impressive array of application soft-
ware already available and several
communication packages offered,
the CompuStar can tackle even your
most difficult programming tasks.
Compare for yourself. Of all
the microcomputer-based multi-
user systems available today,
we know of only one which
offers exactly what you need
and should expect. Excep-
tional value and upward
growth capability. The
CompuStar™. A true price
and performance leader!
3NTE3TEC
Edata
ssystems®
2300 Broad River Rd Columoia SC 29210
1803} 798-9100 TWX 810-666-2115
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160 January 1981 © BYTE Publications Inc
Circle 102 on inquiry card.
Pump Up Your TRS-80 with the ES/F Mass Storage System
THESE FACTS SPEAK FOR THEMSELVES!
CASSETTE ES/F
MINI-DISK
MEET
THE WAFER
SPEED
(Seconds to
load "Blackjack")
56
6
(5' wafer)
%Vz
CAPACITY
(thousands
of bytes)
38
(C-20)
64
(75' wafer)
59
(TRSDOS)
RELIABILITY
(Designed for
digital data?)
NO
YES
YES
▲ Actual Size
Actual Thickness T
SYSTEM COST
(First unit
plus interface)
$60
$250
$800
MEDIA COST
(in quantities
often)
$3.10
cassette
$3.00
wafer
$3.20
disk
Let's face it. Cassette players were not
designed to store digital data and pro-
grams. That's why we designed a digital
storage system using a continuous tape
loop: the Exatron Stringy /Floppy
(ES/F) and the Wafer. There's no ex-
pensive interface to buy-the ES/F
comes ready to pump up your TRS-80.*
Once your TRS-80* is pumped up by
our ES/F . . . you won't want to deflate
it. We're so sure, that we offer an
unconditional 30-day money-back
guarantee and a one-year limited war-
ranty. Over 2,000 TRS-80 * owners have
met the wafer . . . why don't you'll '
EXATRON
STRINGY/Fl
SPEED, CAPACITY
AND RELIABILITY
FOR ONLY $249.5
f
CALL
OUR HOTLINE
(800)-538-8559
IN CALIFORNIA.
CALL (408)-737-71 11
^
<*»«""
exatron, inc.
Commercial Street
ivvale. Calif. 94086
•TRS-80 is a registered trademark
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•3 u:i o in
162 January 1981 © BYTE Publications Inc
Circle 103 on inquiry card.
Orange micro
'SPECIALIZING IN PRINTERS
AND CRT'S"
CENTRONICS 737 (SS)
Word Processing Print Quality
• 18 x 9 dot matrix; suitable for word
processing • Underlining • proportional
spacing • right margin justification • serif
typeface • 50/80 CPS • 9 1 /2" Pin
Feed/Friction feed • Reverse Platen •
80/132 columns
MALIBU
The Smail Business Printer;
Letter Quality & Speed.
• 10 x 9 dot matrix • Letter quality print;
Lower case descenders • High speed; 165
CPS, Bidirectional, Logic seeking • Wide
carriage, Adjustable tractors to 16" •
Vertical forms control • Variable line spac-
ing • User programmable character set •
Dot Resolution Graphics
CENTRONIC 737-1 (List $995)
SCall
MALIBU 165 (List $2495)
$2195
EPSON MX80
Low-Priced
Professional Print Quality
• 9 x 9 dot matrix • Lower case descenders
• 80 CPS • Bidirectional, Logic seeking •
40, 66, 80, 132 columns per line • 64 special
graphic characters: TRS-80 Compatible •
Forms handling • Multi-pass printing • Ad-
justable tractors
EPSON MX80 (List $645)
SCall
OKIDATA MICROLINE SERIES
TRS-80 Graphics Compatibility
• 9 x 7 dot matrix • 80 CPS • 80, 132
columns — 64 shapes for charts, graphs &
diagrams • Double wide characters • 6/8
lines per inch • Up to 3 part copy • Friction
& pin feed • 200 M character head warranty
OKIDATA MICROLINE 80 (List $800)
$599
BASE 2
The Hobbyist Printer With The Most Features
• Graphics • Tractors/Friction Feed • 2K
Input Buffer • RS-232 Serial, Centronics®
Parallel, IEEE-488, 20 ma • TRS-80 Cable
option • 100 CPS • Fast form feed • User
programmable character set • 64, 72, 80,
96, 120, 132 Columns/line • Expanded
characters • Automatic skip-over-perfora-
tion • Horizontal & Vertical tabs • Pro-
grammable vertical line spacing • Intel
8085 Microprocessor — over 40 software
commands
(List $699) $649
BASE 2 800B
TOLL FREE
(800) 854-8275
CA,AK, HI (714) 630-3322
At Orange Micro, we try to fit the right printer to your application.
Call our printer specialists tor free consultation.
ANACOM
Low Cost, High Speed, Wide Carriage
• 9 x 9 dot matrix • Lower case descenders • Wide carriage •
Adjustable tractors to 16" • 150 CPS, Bidirectional, Logic Seeking
ANACOM 150 (List $1350)
SCall
EPSON TX80
• 5 x 7 dot matrix • 125 CPS • Double wide characters • Dot
resolution graphics & 64 special graphic characters • 6/8 line per
inch • Vertical forms control • Adustable tractors • Heavy Duty —
Highly reliable
EPSON TX80 (List $799)
SCall
THE SMALL COMPUTER PRINTER by Brent Weston
This illustrated booklet provides the information you need about today's small
printers. There are many printers available, each with different features and
capabilities. The Small Computer Printer will guide you in determining which
printer best fits your applications. A complete feature comparison chart is
included representing over 40 small printers. A printer is a big investment —
learn all about them before you buy one. $795
TELEVIDEO CRT'S
PRICES SLASHED!
TVI912C") Please Call Toll Free
_ > Prices are too low to
TVI 920C J advertise
PRINTERS
J CENTRONICS 730 Radio Shack Line Printer II (List $795) $ 639
I OKIDATA MICROLINE 82 & 83 $ Call |
l NEC 5530-5 letter quality, RO, parallel, tractors (List $2970) $ 2599 1
PAPER TIGER IDS 440 w/graphics and 2K buffer . . (List $1094)$ 939 1
PAPER TIGER IDS 460 w/graphics, 9 x9dot matrix . . (List $1295)$ Call!
QUME 5/45 typewriter quality (List $2905) $ 2559 j
INTERFACE EQUIPMENT
APPLE II -BASE 2 parallel graphics interface board & cable $ 160
APPLE II- EPSON TX80
■ parallel graphics interface board & cable $ 110 ;
SSMAIO BOARD Apple Serial/parallel interface (List $225)$ 175 1
MICROTRONICS Atari parallel interface $ 69'
ATARI 850 Interface module, serial/parallel $ 199 1
, TRS-80 CABLES to keyboard or Exp. interface * Call]
CALL FOR FREE CATALOG
--
Phone orders WELCOME. Same day
shipment for VISA, MASTER
CHARGE, and AMERICAN EX-
PRESS. Personal checks require 2
weeks to clear. Add 3% for ship-
ping and handling. California resi-
dents add 6%. Manufacturer's
warranty included. Prices subject to
revision.
Orange
flllCfO, Inc.
3148 E. La Palma, Suite E
Anaheim, CA 92806
o
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164 January 1981 © BYTE Publicaeions Inc
dBASE II vs. the Bilge Pumps.
by Hal Pawluk
We all know that bilge pumps suck.
And by now, we've found out— the hard
way— that a lot of software seems to work the
same way.
So I got pretty
excited when I ran
across dBASE II, an
assembly-language rela-
tional Database Man-
agement System for
CP/M. It works! And
even a rank beginner
like myself got it up
and running the first
time I sat down with it.
If you're looking
for software to deal with
your data, too, here are
some tips that will help:
Tip #1: Database Management
vs. File Handling:
Any list or collection of data is, loosely,
a data base, but most of those "data base man-
agement" articles in the buzzbooks are really about
file handling programs for specific applications.
A real Database Management System gives you
data and program independence (no repro-
gramming when data changes), eliminates data
duplication and makes it easy to turn data into
information.
Tip #2: Assembly
Language vs. BASIC:
This one's easy: if you're setting up a
DBMS, you're going to be doing a lot of sorting,
and Basic sorts are s-l-o-w. Run a benchmark on
a Basic system like S*-IV against a relational
DBMS like dBASE II and you'll see what I mean.
(But watch it: I've also seen one extremely slow
assembly-language file management system.)
Tip #5: Relational vs. Hierarchal
& Network DBMS.
CODASYL-like hierarchal and network
systems, around since the 1960's, are being
phased out on the big machines so why get stuck
with an old-fashioned system for your micro? A
relational DBMS like dBASE II eliminates the pre-
defined sets, pointers and complex data structures
of a CODASYL-type DBMS. And you don't need
to be a programmer to use it.
Circle 104 on inquiry card.
dBASE II vs. everything else.
dBASE II really impressed me.
Written in assembly language (with no
need for a host lan-
guage), it handles up to
65,000 records (up to 32
fields and 1000 bytes
each), stores numeric
data as packed strings
so there are no round-
off errors, has a super-
fast multiple-key sort,
and supports ISAM
based on B* trees.
You can use it
interactively with
English-like commands
(DISPLAY 10 PROD-
UCTS), or program it
(so when you've set up the formats, your secretary
can do the work). Its report generator and user-
definable full screen operations mean that you can
even use your existing forms.
And if all this makes your mouth water, but
you've already got all your data on a disk, that's
okay: dBASE II reads your ASCII files and adds
the data to its own database.
Right now, I'm using dBASE II with my
word processor for budgeting, scheduling and
preparing reports for my clients.
Next come job costing, time billing and
accounting.
An Unheard-of Money-Back
Guarantee.
dBASE II is the first software I've seen
with a full money-back guarantee.
To check it out, just send $700 (plus tax in
California) to AshtonTate, 3600 Wilshire Blvd.,
Suite 1510, Los Angeles, CA 90010. (213) 666-4409.
Test dBASE II doing your jobs on your computer
for 30 days. If, for some strange reason, you don't
want to keep it, send it back and they'll refund
your money.
No questions asked.
They know you don't need your bilge
pumped.
Ashton-Tate
©Ashton-Tate 1980
BYTE January 1981 165
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166 January 1981 © BYTE Publications Ire
THE UNBEATABLE S-100
MEMORY I
Mi W i tfiijiiidiiiiaia
DBOOttC
■
,,,,,,........
J/ffiiii/MiiHiiffilT^^
That's the MEASUREMENT systems & con-
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modules, fully compatible with ALPHA
MICRO, CROMEMCO, DYNABYTE , NORTH
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Definitely a winner, the DMB Series is avail-
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and is backed by dedicated customer service
and a one year guarantee.
The DMB6400 uses I/O port addressing for
the bank select feature. A switch provides the
ability to select any one of the 256 I/O ports
for addressing the memory banks. The mem-
ory is configured as four totally independent
16K software selectable banks, with each
bank addressable on any 16K boundary.
Systems
Group
a Division of MEASUREMENT systems &. controls
incorporated
Outstanding features such as those listed
below make the DMB series the UNBEATABLE
S-100 Memory:
• Four independent 16K software select-
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• Each bank is independently addressable
on any 16K boundary.
• Switch selectable bank sizes — from
16K to 64K in 16K increments.
• Eight banks (51 2K) per I/O port for each
of the 256 ports.
• Z-80 4MHz operation with no wait
states using transparent refresh.
• On-board diagnostic LED's.
• Low power — 8 watts maximum.
• Reliable, tested and burned-in memory.
• IEEE S-100 compatible timing.
• One year guarantee.
• Attractive Dealer & OEM Prices.
See your nearest computer dealer, or contact
us for the complete story on the UNBEAT-
ABLE S-100 Memory.
867 North Main St. / Orange, Calif. 92668 / (714) 633-4460
TWX/TELEX: 678 401 TAB IRIN
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168 January 1981 © BYTE Publications Inc.
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Circle 106 on inquiry card.
BYTE January 1981 169
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170 January 1981 © BYTE Publications Inc
We're
known
for our
fine print.
■r
Mv 0«r«* """"
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BYTE January 1981
171
Circle 108 on inquiry card.
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Listing 1 continued:
5045
5058
5855
5068
5065
5078
5075
5080
5685
5098
5095
5108
5105
5118
5115
5120
5125
5130
5135
5 140
1> INDEX OF FIRST POSITION {INTEGER)
2HNDEX OF LAST POSITION (INTEGER)
3>KEV TO EE FOUND CSTRING)
4) STRING ARRAY IN WHICH THE SEARCH IS MADE
DEF FN
1NTEG
F=I
L=J
M=t.F +
IF Q*
IF Q*
IF Q<
IF F<
M = 8
RETUR
FNEND
S< INTEGER I, J,Q*, A*C*> >
ER F,L, M
L> DIV 2
=A*<M> THEN RETURN M
>A*<M> THEN F=M+1
<fl*<M) THEN L=M-1
=L THEN 5890
N M
** END OF BAR
I FIND CENTER OF ARRAY
!IF KEY HAS BEEN FOUND, RETURN INDEX
'CONTINUE SEARCH THROUGH APPROPRIATE HALF
! RETURN IF SEARCH FAILS
:iDE GENERATION PROGRAM *****************
Text continued from page 150:
Since the HP-41C instructions are
of varying length, they quite often
straddle the border between two rows
of bar code. If an instruction starts in
the previous row and ends in the cur-
rent row, the bytes of the instruction
contained in the current row are the
leading partial-function bytes. Alter-
nately, if an instruction starts in the
current row and ends in the next row,
the bytes contained in the current row
are the trailing partial-function bytes.
The third byte of a bar-code row con-
tains, in the 4 high-order bits, the
number of leading partial-function
bytes, and, in the 4 low-order bits,
the number of trailing partial-func-
tion bytes.
A Bar-Code Generating Program
The program given in listing 1,
which runs on a Hewlett-Packard
HP-9845 minicomputer, allows the
user to enter numbered HP-41C in-
structions and will insert the instruc-
tions into a text string for later use.
Each instruction is associated with a
value between 1 and 2240, which
determines the order of execution of
the HP-41C instructions. The number
2240 is given as a maximum since that
is the largest number of bytes avail-
able to the user in program memory.
If the HP-41C program is extremely
long, a renumbering command allows
the user to create gaps in his number-
ing scheme to allow for later insertion
of instructions. Using this program,
the user is able to insert, delete, and
replace instructions; the user can save
the program in a file for later use.
In response to the prompt symbol,
the user may give other single-word
commands to compile and generate
bar code for the HP-41C programs,
save and retrieve the compiled HP-
41C machine language, and list or
delete the entire program. The syntax
and action of each command are
given in table 2 and will be printed
out by the program if a "77" is typed
in response to the prompt symbol.
The basic structure of the program
is a main routine that generates the
prompt symbol and decodes the
input. A series of other routines per-
form the command functions and are
called by a jump table in the main
routine. The input to the main rou-
tine is decoded only to the extent of
determining whether a command or
an instruction has been given, and if
an instruction has been decoded, the
instruction number is calculated. The
instruction is then appended to a text
string, and a pointer to that instruc-
tion is entered into a pointer array at
the position given by the instruction
number. Consequently, the other
routines will be able to retrieve the
program by a linear inspection of the
pointer array.
Replacement, deletion, and renum-
bering of instructions only involve
manipulation of the pointer array,
while insertion requires that the in-
struction number (an integer) must
fall between two existing instruction
numbers. The syntax of the HP-41C
instructions recognized by this pro-
gram follows that of the HP-82143A
thermal printer and of the program
listings distributed by the HP User's
Library, with a few exceptions dic-
tated by the difference between
ASCII and the HP-41C character set.
For example, characters representing
the Greek letter E, the angle sign, and
the =£ sign are represented by the
Text continued on page 178
172 January 1981 © BYTE Publications Inc
fey
fred
Hi*C
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• Are you an active Computer Programmer, Engineer,
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• Do you work with Mathematics frequently?
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Name
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COMPILE
DELETE n
EXIT
GETPROG
GETTEXT
LIST
NUMBER
RENUMBER
RUN
RUNPRIVATE
SAVEPROG
SAVETEXT
Bar-Code Generator Commands
Compiles the current program and loads the compiled code into the array M.
Deletes the instruction given by n from the current program.
Halts execution of the bar-code generator or of the line-number generator.
Retrieves compiled code from a file on cassette tape. (The routine prompts for a
file name.)
Retrieves program instructions from a file on cassette tape. (The routine prompts
for a file name.)
Lists the entire current program.
Automatically generates instruction numbers for HP-41C program entry. The start-
ing number and size of the increment are requested by the routine. This routine is
halted by typing "EXIT".
Renumbers the current program instructions. (The routine prompts for the old
starting number, new starting number and size of the increment.)
Generates the bar code from the compiled code. (It may not be run unless com-
piled code has been generated.)
Generates bar code for a private program.
Stores compiled code for the current program on cassette tape. (The routine
prompts for a file name.)
Stores instructions of the current program on cassette tape. (The routine prompts
for a file name.)
SCRATCH Erases the current program.
?? Displays a list of available commands and syntax rules.
Table 2: A table of commands for the bar-code generating program given in listing 1.
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Shipping charges
174 January 1981 © BYTE Publications Inc
Circle 109 on inquiry card.
Circle 110 on inquiry card.
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^*vc
ROW 1 (1-2;
"ll
ROW 2 (2-5)
ROW 3 (5-8)
ROW 4 (8 - 11)
ROW 5 (12-14)
ROW 6 (14-16)
ROW 7 (16-20)
ROW 8 (20 - 24)
ROW 9 (25 - 3i;
ROW 10 (31 - 37)
ROW 11 (38 - 40)
Figure 2: A demonstration program for the HP-41C. This bar-code program was created by an HP-9845 minicomputer connected to a
Diablo 1650 printer using a Titan 10 metallic daisy-wheel. The program requires twenty registers within the HP-41C.
I The I
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176 January 1981 © BYTE Publications Inc
Circle 111 on inquiry card.
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today, no salesman will ever bother you.
Keep up with the latest technology as you
learn on the world's most popular computer.
If card has been used, write to:
NRI Schools
McGraw-Hill Continuing
rrjj Education Center
S4SvZ 3939 Wisconsin Avenue
■ ■n I Washington, DC. 20016.
Text continued from page 172:
ASCII characters &, @, and #,
respectively. Also, single quotes in-
stead of double quotes are used for
text and alphanumeric labels, and an
alphanumeric append instruction is
indicated by the character A pre-
ceding the single quotes and character
string. The most important routines
called by a command are the compile
routine, which decodes the current
program held in the text string, and
the run routine, which takes the com-
piled machine code and generates the
bit pattern representing the required
bar code.
The program listed here was
developed on an HP-9845A minicom-
puter and contains the functions and
output statements required to gen-
erate bar code on the Diablo 1650
daisy-wheel printer. This is the
system used by the HP User's Library
to produce bar code at request for
any program written either for the
HP-41C or for the HP-67 and HP-97
series. The Diablo 1650 printer is used
with a 96-character Titan 10 metallic
daisy wheel and a Hytype II multi-
strike film ribbon.
The bars are printed by using the
vertical bar (about 160 mils tall and 9
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mils wide) on the Titan 10 with a
horizontal increment of 1/120 inch.
The narrow bars are two characters
wide, the wide bars are four char-
acters wide, and the spaces are three
blanks wide. Three blanks are used
instead of two because the ink
generally spreads a slight amount,
causing the spaces to shrink and the
bars to grow larger. The paper used is
the standard one-ply, 8V4 by 11 inch,
white computer paper. Figure 2 con-
tains the bar code generated by the
User Library's Diablo 1650 for a short
demonstration program written for
the HP-41C.
The subroutine at line 1605 prints a
row of bar code and clears certain
variables in preparation for the next
row of bar code; this routine must be
changed by the user if a different
computer/printer combination is
used. Copies of the resulting bar code
may be made by an office copier if
careful attention is paid to contrast,
sharpness, and bar width. Many of
the less expensive copy machines
shrink the size of the bars, thus
expanding the size of the spaces and
rendering the bar code unreadable.
Most of the commercial printing
houses have the better copiers needed
for this purpose. If many copies are
needed, offset printing may also be
used as a more expensive but very
reliable method for bar-code repro-
duction.
For further assistance in generating
bar code, you can obtain the Hewlett-
Packard Creating Your Own HP-41C
Bar Code manual (part number
82153-90019), which contains a
listing of the program given here and
a discussion of bar codes and bar-
code generation. ■
Editor's Note:
The Hewlett-Packard bar-code format is
partially compatible with the PAPER-
BYTE 9 format designed by BYTE Publica-
tions Inc in 1977. Fortunately, the com-
patibility is in the most important place, the
representation of 1 and bits within a line
of bar code. Although Hewlett-Packard
uses different header and trailer bytes to
frame the actual bytes of data, the encoding
scheme used to encode both the data and
the header and trailer bytes is the same in
both Hewlett-Packard bar codes and
PAPERBYTE® . Hewlett-Packard's deci-
sion in this direction strenghtens the
authority of the PAPERBYTE 9 format,
and we feel that this is an important step
toward the standardization of machine-
readable bar code.... GW
178 January 1981 © BYTE Publications lnc
Circle 113 on inquiry card.
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AND FLOPPIES TO WORK WITH N.S. AND
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SOFTWARE
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MAILMERGE 100
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N.S. PASCAL 160
MAGIC WAND 290
CBASIC 100
BOOKKEEPER 800
ADDITIONAL SOFTWARE DISCOUNTS
WITH SYSTEM PURCHASE
GRAHAM-DORIAN
JOB COSTING$700
INVENTORY.. 475
CASH REG. . . 475
APARTMENT . 475
MEDICAI 700
STRUCTURED SYS
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TECH. ASSISTANCE: WE TRY TO HELP INTERFACE AND
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Open Mon.-Fri., 8:00 AM - 5:00 PM Dealer Inquiries Invited.
Our Systems Work!
All systems normally tested and
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Prompt repairs and warranties.
Circle 114 on inquiry card.
BYTE January 1981 179
When You Have To
Face A Deadline
Communication Arts. Huntington Beach. CA
Arm Yourself With
Pascal/MT+®
From
VISA*
master charge
MT Micro SYSTEMS
1562 Kings Cross Drive
Cardiff, California 92007 (714) 753-4856
We ship on 8" single density and 5-1/4" North Star single density.
Other formats available. Ask us.
CP/M is a r egister ed trademark of Digital Research MP/M is a trademark of Digital Research Pascal/Ml"-*- is a registered trademark of MT Micro Systems
MT MicroSYSTEMS SOFTWARE ARSENAL:
Pascal/MT+ (
Screen
Editor*
'Contact us tor the exciting news about this leap forward in state ot the art technology.
Pascal/MT+® provides you with the power to meet your
deadlines head-on! Compiling directly to native code without
slowing down to generate P-code or assembly language,
Pascal/MT+® generates ROMable, optimized native code and
gives you the flexibility ot modular compilation; and it does
so at speeds up to 1000 lines per minute while the others are,
at best, one third as tast! Even when you're not facing a
deadline, Pascal/MT+® never wastes your time! Nobody likes
to wait for a computer. The Pascal/MT+® won't keep you
waiting! Your software written in Pascal/MT + ® is totally
portable to most 8 and 16 bit processors. The Pascal/MT+®
system provides you with a powerful debugging tool. With
Pascal/MT+® you do have an effective weapon against
monstrous deadlines.
Pascal is the most popular programming language in use
today. You can use Pascal/MT+® to replace assembly
language in your ROM based applications, BASIC and COBOL
in your business applications, FORTRAN in your scientific
applications, or interpreted Pascal in all of your appiications.
Because Pascal programs are easy to write, read, and
maintain; and because the Pascal/MT + ® system contains all
of the features you need for your applications, you can get
your job done on time! In fact, you may never need assembly
language or any other high level language again.
Pascal/MT+® has the speed, extensions, and portability to
stock your software arsenal for years to come!!!
ISO STANDARD Pascal
Pascal/MT+® supports the ISO Standard. We send the results
of our compiler's performance on the Validation Suite. Also,
for portability the MT+ compiler can warn you when you are
using non-standard extensions.
Modular Compilation
Pascal/MT+® generates the same industry standard relocat-
able code used in FORTRAN and PL/I. Both Pascal and
assembly language modules may be separately compiled
and then combined to produce a final program. With modular
compilation available, the run time overhead is as small as
256 bytes and is typically 1200 bytes.
Native Code Generation
Pascal/MT+® native code is faster than interpreted Pascal
and other native code Pascals in benchmark test programs.
Optimization steps taken during compilation perform such
enhancements as removing redundant PUSH/POPsequences
and using single increment and decrement instructions when
adding or subtracting small literal numbers. In addition, our
disassembler interleaves your Pascal source code and
symbolic assembly code to help you write more efficient
programs.
Extras
• Predeclared a-rays INP and OUT directly access I/O ports.
• INLINE instruction for inserting assembly language between the Pascal
statements. A built-in mini assembler translates the instructions at
compile time. Constant tables may be generated using the inline facility.
• ABSOLUTE assembly language procedure declarations for using pre-
assembled routines.
• INTERRUPT procedures.
• CHAINING for transfering control from one program to another.
• ELSE clause on the case statement.
• REDIRECTED I/O facilities allow user written character level I/O drivers to
be called via READ and WRITE statements.
• HEX literal numbers are supported.
• Built in procedures/functions:
—bit test, clear, set.
—byte swap.
—return hi or lo byte.
—Shift left and right.
—Return the address of a data item or routine.
—Return the size of a data item.
—Enable, disable interrupts.
—All standard file I/O plus random read and write to files.
• Include files supported.
• Source code for run-time package included.
• Business (18 digit) arithmetic.
• Scientific (6.5 digit) arithmetic.
• AMD 9511 hardware support.
• Transcendental functions.
• Full string capability (UCSD compatible).
Symbolic Debugger
Our symbolic debugger is optionally linked into the final program. If you're
tired of feeling like you're in the dark when using a higher level language, the
Pascal/MT* 19 debugger lights up the darkness. The debugger traces one or
more lines of Pascal code or executes the program until a line number or
symbolic breakpoint is reached. To follow program flow the name of each
procedure and function entered is displayed by the debugger. The contents of
simple and complex variables may be displayed by name. The debugger may
be used in a ROM environment so that program flow and variable contents are
visible.
Distribution disk contains
• BCD compiler configured for your target machine.
• Floating point compiler configured for your target machine.
• Linker.
• Interactive Symbolic Debugger.
• Run time package in source and object form.
• Pascal library and utility routines.
• Manual containing an Applications Guide and a Language Guide.
• Sample programs.
System Requirements
• Operating System: CP/M® (or equivalent such as CDOS. IMD0S, etc.)
• Memory requirements:52Kminimum.
• Host Machines: 8080 or Z80.
• Target Machines: 8080/Z80. 68000, Z8000, 8086/8088, 6809.
• Resident compilers for all processors will be forthcoming as operating
systems become available.
MT MicroSYSTEMS has a very reasonable, graduated, one time royalty
arrangement for free standing software generated by Pascal/MT+*\
Ordering
8 bit processor target machines:
8080/Z80, 6809 S250.00 each
16 bit processor target machines:
68000, Z8000, 8086/8088 $500.00 each
Copies on North Star Disks $50 additional.
User's guide alone
(refundable with system purchase): $30.00
Note: Not all 16-bit CPU code generators are available at Ibis time: contact us (or information
before ordering.
OEM and Dealer inquiries invited.
Circle 115 on Inquiry card.
Systems Notes
Numerical
Analysis for
the TRS-80
Pocket Computer
Mike Salem, 26A Delancey St, London NWl 7NH, England
Complicated programs can often be easily modified to
fit into the new pocket computers. I've taken three pro-
grams from the December 1979 issue of BYTE and
modified them to run on the Radio Shack TRS-80 Pocket
Computer (sold as the Sharp PC-1211 outside of the
United States). The Pocket Computer has a 24-character
LCD (liquid-crystal display), twenty-six fixed variables,
and 1424 bytes of programmable memory.
One of the programs I modified was the discrete-
Fourier-transform program that appeared in "Frequency
Analysis of Data Using a Microcomputer" by F R
Ruckdeschel (December 1979 BYTE, page 10). I also com-
bined two programs that compute the time-domain
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Accounts Receivable $95.00
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Payroll-Non California state
income tax calculations
(add to California payroll) $95.00
General Ledger $95.00
Multiple profit center option
for general ledger $95.00
Manuals (each) $20.00
Formats: Any 8" single or double density. TRS-80 Mod II, Northstar
DD. Vector Graphics. Super Broin, many others.
Runs on Beehive. Soroc. Hazeltine. ADDS, Televideo, SOL, TRS-80
Mod II, HEATH, ACT V. Intertube II. Altos. ADM and many other
terminals. All programs in CBASIC under CP/M (includes source).
Synergetic Computer Products
575 Middlefield Avenue Suite J, Palo Alto, CA 94301
(415) 328-5391
VISA ■ Masler Charge • COD • Company Check
TRS-80 is a trademark of Radio Shack. Inc CP/M is a trademark of Digifal Research
response of a system with a given transfer function into a
single program ("Noniterative Digital Solution of Linear
Transfer Functions" by Brian Finlay, December 1979
BYTE, page 144). The modified programs have all of the
features of the originals, with the obvious omissions of
printing and plotting.
Incidentally, it is important to note that the TRS-80
Pocket Computer, in common with many machines,
allows BASIC lines to contain multiple statements (sav-
ing 3 bytes of programmable memory for each line
number omitted). Although this feature is useful in itself,
the TRS-80 Pocket Computer also has an IF statement
that can control all of the remaining statements in the
Listing 1: A discrete-Fourier-transform program for the TRS-80
Pocket Computer. This program was modified from "Frequency
Analysis of Data Using a Microcomputer" by F R Ruckdeschel
(December 1979 BYTE, page 10). Statements entered on the
same line are separated here for clarity.
10
11
190
250
290
340
370
410
420
510
710
770
800
810
815
820
REM BYTE DEC 79
RADIAN
INPUT "1ST X? ";Z,"LAST X? ";Y,"#OF POINTS? ";N
1=1
INPUT "I/P SCALE FACTOR? ";I
IF I< 1 GOTO 250
D = (Y-Z)/(N-1)
Q =
V = i/DI
U = V/(N-1)
FOR 1=1 TON
PAUSE "NEXT § = ";I
BEEP 1
INPUT "NEXT F(T) VALUE? ";0
A(I + 26) =
NEXT I
B =
FORI = 27TON + 26
IFB>A(I)LETB = A(I)
NEXT I
FORI= 27TON + 26
A(I) = A(I)-B
NEXT I
B = ABSB
T =
FORI = 27TON + 26
IFT<A(I)LETT = A(I)
NEXT I
FOR 1=1 TON
W = (I-1)*U
C =
P =
FORM=l TON
X = Z + (M-1)*D
G = WX
C = C + A(M + 26)*COSG
P = P + A(M + 26)*SING
NEXTM
F = V(PP + CC)*D
IF 1=1 LETC = C-NB
F = D*ABSC
BEEP 1
PRINT U*(I-1);"RAD/S"
PRINT "AMPL. = ";F
IF C<>0 LET O = ATN(P/C)*180/tt
PRINT "PHASE = ";0
NEXT I
BEEP 3
PRINT "END OF RUN"
END
182 January 1981 © BYTE Publications Inc
Circle 124 on inquiry card.
One Stop
Shopping
New CPU Card
Completes the
Package.
Now Tarbell offers a Z-80 S-100 CPU/IO board that
rounds out its product line. Along with the single or
double density floppy interface, the 32K memory card
and the S-100 bus in the cabinet, this new CPU board
means that Tarbell now offers everything needed to
build a system. Just add a CRT and printer, and you're
in business. Tarbell is now your one-stop shopping
source.
One of the outstanding features of this new CPU board
is memory-management hardware that allows dynamic
mapping of logical to 1 Megabyte of physical memory in
4K blocks. Moreover, the CPU board is especially
designed to make it easier to implement multi-user
operating systems, such as MP/M™ from Digital
Research. It can run at 2 or 4Mhz, jumper selectable. It
has two RS-232 Serial Ports (one for printer and one for
CRT), with full handshaking capability.
One of its additional important features is a crystal-
controlled programmable timer, which can be used for
time-of-day clock and multi-tasking operations.
Programmable priority masked vectored interrupt
hardware is another useful feature.
In addition to all the features of the new CPU card, the
double density floppy interface has DMA which makes
the multi-tasking operation quite efficient. Also, the 32K
memory board is static, resulting in a reliable memory.
The Tarbell System with all three cards can be
expanded for more memory and thus provides the
ultimate in flexiblity.
Now Tarbell has it all.
^?1ot5
Circle 116 on Inquiry card.
The One-Stop Shopping Service
950 Dovlen Place, Suite B
Carson, CA 90746
(213) 538-4251
MP/M is a trademark of Digital Research.
BYTE January 1981 183
Systems Notes,
same line. Since this makes listings a bit difficult to read, I
prepared listings 1 and 2 with a separate statement on
each line.B
Listing 2: A program for the TRS-80 Pocket Computer that
computes the time-domain response of a system with a given
transfer function. The program shown was combined and
modified from two programs contained in "Noniterative Digital
Solution of Linear Transfer Functions" by Bryan Finlay
(December 1979 BYTE, page 144).
10
70
150
160
240
250
330
370
380
REM "TF: TRANSFER FCN - BYTE DEC 79"
RADIAN
INPUT "CONST.? ";K,"#TERMS NUM.? ";E,"#TERMS
DEN.?";L
IF E = GOTO 240
FORG = 27TOE + 26
O=10 + G
INPUT "RL, NUM.? ";A(G),"IM, NUM.? ";A(0)
NEXTG
IF L = GOTO 330
FORH = 47TOL + 46
O=10 + H
INPUT "RL, DEN.? ";A(H),"IM, DEN.? ";A(0)
NEXTH
FOR G = 1 TO L
= 66 + G
Q = 76 + G
A(0)=1
A(Q) =
IF E = GOTO 450
FOR H = 1 TO E
D = A(26 + H)-A(46 + G)
C = A(36 + H)-A(56 + G)
M = V(DD + CC)
410
450
465
470
500
501
520
620
650
710
730
N = ATN(C/D)
IFD<0LETN = N-i
A(0) = MA(0)
A(Q) = N + A(Q)
NEXTH
FOR R = 1 TO L
IF R = G GOTO 501
D = A(46 + R)-A(46 + G)
C = A(56 + R)-A(56 + G)
M = V(DD + CC)
N = ATN(C/D)
IFD<0LETN = N-ir
A(66 + G) = A(66 + G)/M
A(76 + G) = A(76 + G)-N
NEXTR
NEXTG
INPUT "T(0)7 ";0,"DT? ";S,"# STEPS? ";N
:T = + NS
U=-S
FORQ=l TON
:U = U + S
V =
w=o
H=l+INT((U-0)/S)
FOR G = 1 TO L
X = A(66 + G)*EXP( - UA(46 + G))
Y = A(76 + G)-UA(56 + G)
V = V + X*COS Y
W = W + X*SINY
NEXTG
Z = KV(VV + WW)*SGN V
BEEP 1
:PRINT"TIME = ";U
PRINT "RESP. = ";Z
;NEXT Q
ECHO SERIES™ speech synthesizers
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speech synthesizer for the Apple* is the first of a
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that made the Speak & Spell* * a success.
The initial operating system allows the creation of
your own vocabulary with phonemes (word sounds)
while using very little RAM memory (approx. 800 bytes
+ 20 bytes/word). Enhanced operating systems and
vocabulary ROMs will be offered as they become
available.
The ECHO ][™ comes complete with speaker, instruc-
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*Trademark of Apple Computer ** Trademark of Texas Instruments
Circle 117 on Inquiry card.
Speed up your PET programming with The BASIC
Programmar's Toolkit™ now only $39.95.
Don't waste valuable programming time if there's an
easier way to go. Here it is: The BASIC Programmer's
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The BASIC Program-
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This extra ROM store lets you avoid
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ed on a circuit board attached on
the side of your PET, depending on
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There are three versions of BASIC,
and three Toolkit models. If you
see ***COMMODORE BASIC***
when you turn on your PET, it
uses model TK-80R If you see
###COMMODORE BASIC###,
it uses model TK-160. If you see
***COMMODORE BASIC 4.0***,
it uses model TK-4.0. Other
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would di:
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for
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DELETE
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APPEND
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How Toolkit makes your programming easier:
FIND locates and displays the BASIC program lines
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If you were to type FIND A$, 100-500, your PET's screen
would display all lines between line numbers
100 and 500 that contain A$.
RENUMBER renumbers theentire
program currently in your PET.
You can instantly change
all line numbers and all
references to those
numbers. For instance,
to start the line numbers
with 500 instead of 100,
just use RENUMBER 500.
HELP is used when your program
stops due to an error. Type HELP,
and the line on which the error
occurs will be shown. The erroneous
portion of the line will be indicated
n reverse video on the screen.
These simple commands, and the other
seven listed on the screen, take
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Get the BASIC Programmer's
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PALO ALT© iCs
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The Toolkit is fully assembled.
It is not a kit and requires no
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FIND
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I want to save
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Send me The BASIC Programmer's Toolkit that will give
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Fill in the appropriate line below:
Qty TK-4.0 Toolkit(s) @ $39.95 each
Qty TK-160 Toolkit[s) @ $39.95 each
Qty TK-80P ToolkitCs) @ $59.95 each
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Please include the amount of the Toolkit, plus $2.50 for
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INVOICING AND PAYROLL (Small Business Systems
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ordinated system. $225. ..per module. ..$1299 for the
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(5) ADVENTURE »1-#9 (Scott Adams - Adventure
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actually alphabetize (or any other type of sort) 4 disk
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use DSM with the RS MAILING PROGRAM ...works
under TRSDOS. ..$150.
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language monitor and disassembler.. .can be used to
see and modify memory or disk sectors. ..contains all
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under TRSDOS.. .$39.95.
(9) BLINK BASIC LINK FACILITY (Racet Computes)..
Link from one BASIC program to another saving all
variables chain programs without losing variables
...$50.
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variables or strings (with the line number in which
they appear) ..$50.
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SUPERZAP (to see. print or change any byte on a
diskette) ...Disassembler and MOD-II interface to the
MICROSOFT EDITOR ASSEMBLER PLUS including
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The software essential to interface any of the popular
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coming soon (November 1?)
{14) HARD DISK DRIVES. coming soon (Nov. 1?).
(15) H & E COMPUTRONICS, INC. SHARE-A-
PROGRAM DISKETTE #1... works under TRSDOS. ..a
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processor. ..mail system. ..mortgage calculations...
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50 diskettes. ..comes complete with index-dividers, tilt
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(18) MASTER PAC 100... 100 essential programs...
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manual and 2 diskettes.. .$99.95.
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includes 125 page manual and two diskettes. ..$149. 95.
(20) EDITOR ASSEMBLER (Galactic Software Ltd.)...
the first user oriented Editor Assembler for the
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...$229.00.
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source programs into machine language... increases
program execution by 3-10 times. ..$395.
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stores 2,500 names per disk. No sorting time is
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changed and edited ...built in error checking. ..$199. 95.
(24) COMPUTER GAMES (SBSG) ...Mean Checker
Machine. Star-Trek III, Concentration, Treasure Hunt.
Banco, Dog Star Adventure. ..$74.95.
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(2) CP/M HANDBOOK. (Sybex). a step-by-step
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CP/M commands., numberous sample programs..
practical hints. ..reference tables. ..$13. 95.
(3) GENERAL LEDGER, ACCOUNTS RECEIVABLE,
ACCOUNTS PAYABLE, INVENTORY CONTROL,
AND PAYROLL (Peachtree Software), requires CP/M
and MICROSOFT BASIC. .professional business
systems. ..turn key operation ...can be used as single
modules or as a coordinated system. ..$500 per
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(4) WORD-STAR. ..The ultimate word processor. ..a
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andy CP/M based mail program, .,$150.
(6) SELECTOR III (Micro-Ap)... complete data
management system.. .user defined fields and codes,, .
manages any list defined by the user, ..includes
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accounts receivable and accounts payable,. .requires
CBASIC-2...$295.
(7) SELECTOR IV (Micro-Ap) the ultimate data
management system. ..all features use the SELECTOR
III plus. data file format conversions. .full page report
formatter, .computations. ..global search and replace
...hard disk compatible.. .data/text merging. ..$550.
(8) GLECTOR (Micro-Ap). ..add on package to the
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(9) CBASIC-2 a non-mtesactive BASIC used for
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(10) MICROSOFT BASIC an enhanced version of the
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(11) MASTER TAX (CPAids).. professional tax
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payroll register. W2's and payroll checks. ..$450.
(13) ELECTRIC PENCIL (Michael Shrayer Software)
...Complete word processor with extensive editing
and printer formatting features, ..$275 (Standard
printer version) $300 (DIABLO. NEC or QUME
version)
(14) BASIC COMPILER (Microsoft) ..changes your
source programs into machine language, .increases
program execution by 3-10 times. ..$395.
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A
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NEW!!!
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Languages Forum
A Bug in BASIC
W D Maurer, Dept of Electrical Engineering and
Computer Science, The George Washington University,
Washington DC 20052
The purpose of this article is to describe and analyze a
particular bug that is common to a number of BASIC sys-
tems for microcomputers. Specifically, of fifteen micro-
computers surveyed, four of them had this particular bug
in their BASIC, nine of them did not, and the remaining
two had the bug in one version of their BASIC but not in
the other. The bug is illustrated by a simple BASIC pro-
gram that runs properly on the systems that do not have
the bug and encounters a run-time error on systems that
do have it. By comparing the program inputs that cause
erroneous behavior with those that do not, the cause of
the bug is traced, and two possible corrections are sug-
gested. One of these is quite elegant and results in almost
no change in running time or space requirements. It is, of
course, rather common for programmers to accuse either
the hardware or the system software of being at fault
when their programs have bugs. The analysis here may
serve as an example of a valid isolation technique of a
bug's source in system software.
The program illustrating the bug is shown in listing 1.
It accepts some numbers from the keyboard, checks for
the presence of the number 0, and checks for duplica-
tions. Sample inputs and outputs are shown in listing 2.
Of the six test cases in listing 2 on page 190, only Test IV
and Test VI cause problems; both correct and erroneous
behavior are shown. Table 1 gives the names of the
microcomputer systems and their respective behavior.
There are no easy explanations for the presence of this
bug. As should be evident from table 1 on page 194,
many of the lowest-priced systems are free from the bug,
Listing 1: A BASIC program that sometimes causes a NEXT
WITHOUT FOR error.
10 DIMT(100)
20 PRINT "HOW MANY NUMBERS?"
30 INPUT N
40 PRINT "INPUT ";N;" NUMBERS"
50 FOR C = 1 TO N
60 INPUT T(C)
70 NEXT C
80 FOR C = 1 TO N
90 IFT(C) = 0THEN 130
100 NEXTC
1 10 PRINT "ZERO IS NOT PRESENT"
120 GOTO 140
130 PRINT "ZERO IS PRESENT"
140 FORR = lTON-l
150 FORC = R + lTON
160 IFT(R) = T(C)THEN210
170 NEXTC
180 NEXT R
190 PRINT "NO DUPLICATIONS"
200 GOTO 220
210 PRINT "T(";R;") = T(";C;")"
220 END
as are many of the highest-priced systems. A large pro-
portion of the BASIC systems surveyed, with and with-
out the bug, were produced by a single software supplier;
other systems, with and without the bug, were not. We
draw no general conclusions about the general relative
suitability of the various systems; many of the systems
that exhibit the bug have numerous advantages when
compared to systems that do not have it.
As we shall see, there are various ways to circumvent
the bug. That is, we can rewrite the program so that it
still does the same thing as before, without encountering
the bug, and we can also do this in a variety of ways.
This, however, does not change the fact that there is a
bug. We have the incontrovertible evidence of a simple
program that clearly ought to run, that does run on nine
microcomputer systems, and does not run on another
four systems.
The bug has to do with FOR... NEXT loops in which
there are abnormal exits. Many programmers are still
under the erroneous impression that this is illegal — that
you are not supposed to jump out of a FOR loop. On the
contrary, it is illegal to jump into such a loop. Abnormal
exits from loops are absolutely necessary in programming
for such tasks as searching (as illustrated here), error
exits, and, in general, the treatment of special cases.
Let us now analyze the bug. It is clear from listing 2
that the problem arises at statement 180. The error
message, NEXT WITHOUT FOR ERROR IN 180, means
that there is a NEXT statement (180 NEXT R) that does
not have a corresponding FOR statement. But this is
clearly false; there is a corresponding FOR statement (140
FORR=lTON-l).
Is the problem the expression N — 1 in statement 1407 If
statement 140 is changed to 140 Z = N-1 and 145 FOR
R = l TO Z, the bug is still there. So this is not the prob-
lem.
Can we ever get to statement 180 without encountering
the bug? If we look at Test I, we see the message NO
DUPLICATIONS. Clearly this was printed at statement
190, and there are no jumps to 190 in the program, so the
only way to get to 190 is through 180. Thus, in Test I, the
computer got through statement 180 with no problems.
How did we get to statement 1807 There are no jumps
to 180 in the program either; so we must have gotten
there from 170 NEXT C. Could this have caused the
problem? Since the problem is that the system thought it
was not in a loop when it got to statement 180, we now
consider the possibility that the system thought it was
coming out of an outermost loop at 170 NEXT C.
Could the system have thought it was coming out of
one of the earlier loops? The FOR statement correspond-
ing to 170 NEXT C is 150 FOR C = R + 1 TO N. But there
are two earlier FOR loops that use C, one starting at 50
and the other starting at 80. Could this be the source of
the confusion?
If so, it was probably the loop starting at 80 that
caused the problem. The loop starting at 50 is completely
self-contained, but the loop starting at 80 has an abnor-
mal exit: 90 IF T(C) = THEN 130. Here is our hypothe-
188 January 1981 © BYTE Publications Inc
From Digital Research
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Circle 120 on Inquiry card.
BYTE January 1981 189
Languages Forum.
Listing 2: Test runs of the program in listing 1. Test IV and Test VI can each return two sets of behavior, one for versions of BASIC
that correctly execute the program and one for versions of BASIC that do not.
]RUN
HOW MANY NUMBERS?
?5
INPUT 5 NUMBERS
?6
71
?8
?10
?12
ZERO IS NOT PRESENT
NO DUPLICATIONS
JRUN
HOW MANY NUMBERS?
?5
INPUT 5 NUMBERS
?4
?7
?2
?4
?10
ZERO IS NOT PRESENT
T(1) = T(4)
JRUN
HOW MANY NUMBERS?
?5
INPUT 5 NUMBERS
?3
?7
?9
?23
?9
ZERO IS NOT PRESENT
T(3) = T(5)
> RUN
HOW MANY NUMBERS?
?5
INPUT 5 NUMBERS
?4
?0
71
?12
?6
ZERO IS PRESENT
NO DUPLICATIONS
Test I
Test II
Test III
Test IV (correct)
]RUN
HOW MANY NUMBERS?
?5
INPUT 5 NUMBERS
?2
?6
?8
71
?0
ZERO IS PRESENT
T(D=T(4)
RUN
HOW MANY NUMBERS?
?5
INPUT 5 NUMBERS
71
?0
?24
?1
?24
ZERO IS PRESENT
T(3) = T(5)
]RUN
HOW MANY NUMBERS?
?5
INPUT 5 NUMBERS
?4
?0
71
?12
?6
ZERO IS PRESENT
?NEXT WITHOUT FOR ERROR IN 180
]RUN
HOW MANY NUMBERS?
?5
INPUT 5 NUMBERS
71
?0
?24
?1
?24
ZERO IS PRESENT
?NEXT WITHOUT FOR ERROR IN 180
Test V
Test VI (correct)
Test IV (erroneous)
Test VI (erroneous)
sis: when this abnormal exit was taken, the system did
not realize that it was not in a loop any more. Then,
when it came to 170, it thought that it was finally coming
out of the loop that started at 80. Since this loop was an
outermost loop, the system thought that it was no longer
in any loops at all. Under these conditions (if they ex-
isted), a NEXT statement, such as the one at 180, would
truly be an error.
This hypothesis is certainly plausible, but it has to be
checked. Specifically, does it account for the fact that
Tests I and III worked, while Tests IV and VI did not7 In
Tests I and III, we print ZERO IS NOT PRESENT. This
was done at 110, and it is not too hard to see that in this
case the abnormal exit is not taken; we never jump from
90 to 130. In Tests IV and VI, we print ZERO IS PRE-
SENT, and under those conditions we do jump from 90 to
130. This behavior is consistent with our hypothesis.
Why did Test V work? The message T(1)=T(4) is
printed by Test V. Looking at statement 210, we can see
that we must have had R = l. Looking at statement 140,
we can see that we must have been in the first iteration of
that loop (since R = l) and that we made an abnormal exit
from 160 to 210. Thus 180 was never executed. Again this
behavior is consistent with our hypothesis.
What happens if we change C to D in the earlier loop?
If we go back to statements 80, 90, and 100, and change C
to D throughout these statements, the bug disappears. If
we change C to D throughout the loop at statements 50,
60, and 70 (and leave 80, 90, and 100 without change),
the bug does not disappear. This tells us two things. First,
the bug has nothing to do with the loop at 50, 60, and 70
(again consistent with our hypothesis). Second, the bug
definitely does have something to do with variable
names. The confusion is between FOR C at 80 and FOR C
at 150, and the confusion goes away if one of these is
changed to FOR D and if other corresponding changes
are made.
What happens if we change the earlier loop so that
190 January 1981 © BYTE Publications Inc
Computer experts
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That's why when they shop
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The biggest challenge
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Languages Forum.
System
Bug?
Alpha Micro (interpreter)
no
Alpha Micro (compiler)
no
APPLE (Integer BASIC)
no
APPLE (Applesoft BASIC)
yes
Archives (MBASIC)
yes
Atari 800 and 400
yes
Commodore PET
yes
Cromemco
no
Heath H-11A
no
Hewlett-Packard HP-85
no
IMSAI VDP-80
no
North Star Horizon
no
Ohio Scientific Challenger 1P
yes
Radio Shack TRS-80 Model I (Level
BASIC)
no
Radio Shack TRS-80 Model I (Level II BASIC)
yes
Radio Shack Model II
no
Texas Instruments 99/4
no
Vector Graphics (MBASIC 5)
no
Table 1: A list of computer systems' running
versions of
BASIC that do and do not run corre
ctly due to a
bug in their
handling of the FOR... NEXT loop.
The system'
■ listed here
were tested on November 12 and li
1, 1980.
there is no FOR statement? This can be done by simply
changing 80 to C = l and then replacing 100 by two
statements: 100 C = C + 1 and 105 IF C < = N THEN 90. If
this is done, even though the same variable name C is still
used in two places, the bug disappears. This is further
evidence for our hypothesis, because now there is no con-
fusion about which FOR statement corresponds to the
NEXT statement where the bug appears.
The above changes illustrate ways of working around
the bug. If you have a FOR loop with an abnormal exit,
you will never find the bug if that particular FOR loop
has a uniquely named loop-index variable. That is, if it
ends with NEXT a, then nowhere else in the program
should there be a statement NEXT a with the same a.
Now let us dig a little deeper. At statement 90, the exit
goes to 130, while the loop involves only statements 80,
90, and 100. Why can't some of our BASIC systems tell
that the exit at 90 is an abnormal exit? Presumably
because they have no information whatsoever as to
where loops start and end. Why would this be the case7
There is a plausible explanation having to do with the
relationship between the BASIC interpreter and its
editor.
Many of the BASIC systems that exhibit the bug have a
very close coupling between running and editing a BASIC
program. The two activities, in fact, can be carried on
alternately with very little internal data processing to ac-
company the switch-over from running to editing or from
editing to running. Simple editing, however, may pro-
duce far-reaching changes in the loop structure of a pro-
gram. Adding or deleting a single FOR or NEXT state-
ment can cause the pairing of other FOR and NEXT state-
ments to be changed, even though they are widely
separated from the added or deleted statement. There-
fore, the decision must have been made not to keep
FOR... NEXT pairing information at run time, with the
hope that it would never really be needed. As we can see,
Murphy's law is applied in this case with a vengeance.
Let us now examine the bug technically in terms of
stacking considerations. This will also suggest methods of
fixing the bug.
194 January 1981 © BYTE Publications Inc
AH JH| ^P Licenced by Sinclair Research Ltd.
Microcomputer
for everyone at
a Micro Price
The LMicrofkeJ
The unique
and valuable
components of the MicroAce
The MicroAce is not jusl another personal
computer. Quite apart from its exceptionally low
price, the MicroAce has two uniquely advanced
components: the powerful BASIC interpreter, and
the simple teach yourself BASIC manual.
The unique versatile BASIC interpreter offers
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• Unique 'one-touch' key word entry: the
MicroAce eliminates a great deal of
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• Unique syntax check. Only lines with correct
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faults only discovered when you try to run
them.
• Excellent string handling capability takes up
to 26 string variables of any length. AH strings
can undergo all relational tests (e.g.
comparison). The MicroAce also has string
input to request a line of text when
necessary. Strings do not need to be
dimensioned.
• Up to 26 single dimension arrays.
• FOR/NEXT loops nested up 26.
• Variable names of any length.
• BASIC language also handles full Boolean
arithmetic, conditional expressions, etc.
• Exceptionally powerful edit facilities, allows
modification of existing program lines.
• Randomise function, useful for games and
secret codes, as well as more serious
applications
• Timer under program control.
• PEEK and POKE enable entry of machine code
instructions, USR causes jump to a user's
machine language sub routine.
• High resolution graphics with 22 standard
graphic symbols.
• All characters printable in reverse under
program control.
• Lines of unlimited length.
'Excellent value' indeed!
For just $149.00 {including handling charge) you
get everything you need to build a personal
computer at home... PCB, with IC sockets for all
ICs; case; leads for direct connection to a cassette
recorder and television (black and white or color);
everything!
Yet the MicroAce really is a complete, powerful,
full facility computer, matching or surpassing other
personal computers at several times the price.
The MicroAce is programmed in BASIC, and you
can use it to do quite literally anything, from playing
chess to managing a business.
The MicroAce is pleasantly straightforward to
assemble, using a fine tipped soldering iron. It
immediately proves what a good job you've done:
connect it to your TV . . . link it to the mains adaptor
... and you're ready to go.
Fewer chips, compact design,
volume production-more power
per Dollar!
The MicroAce owes its remarkable low price to its
remarkable design: the whole system is packed on
to fewer, newer, more powerful and advanced LSI
chips. A single SUPER ROM, for instance, contains
the BASIC interpreter, the character set, operating
system, and monitor. And the MicroAce 1K byte
- a new generation of
miniature computers
A COMPLETE COMPUTER
for $149.00 for 1K Kit
Post and Packing FREE
(Add 6% Tax for Shipments inside California}
RAM (expandable to 2K on board) is roughly
equivalent to 4K bytes in a conventional computer
typically storing 100 lines of BASIC. (Key words
occupy only a single byte.)
The display shows 32 characters by 24 lines.
And Benchmark tests show that the MicroAce is
faster than all other personal computers.
No other personal computer offers this unique
combination of high capability and low price.
The MicroAce teach-yourself
BASIC manual.
If the features of the BASIC interpreter mean
little to you don't worry. They're all explained in the
specially-written book free with every kit! The book
makes learning easy, exciting and enjoyable, and
represents a complete course in BASIC
programming from first principles to complex
programs. (Available separately-purchase price
refunded if you buy a MicroAce later.)
A hardware manual is also included with every kit.
The MicroAce Kit:
$149.00 with IK COMPLETE
$169.00 with 2K
Demand for the MicroAce is very high: use the
coupon to order today for the earliest possible
delivery. All orders will be despatched in strict
rotation. If you are unsuccessful in constructing
your kit, we will repair it for a fee of $20.00, post and
packing FREE. Of course, you may return your
MicroAce as received within 14 days for a full
refund. We want you to be satisfied beyond all
doubt and we have no doubt that you will be.
Z80 A microprocessor
chip, widely recognised
iis the besi ever made.
Your MicroAce kit
contains...
• Printed circuit board, with
IC sockets for all ICs.
• Complete components set,
including all ICs all
manufactured by selected
world-leading suppliers.
New rugged keyboard,
touch-sensitive, wipe-clean.
Ready-moulded case.
Leads and plugs for
connection to domestic TV
and cassette recorder.
(Programs can be SAVEd
and LOADed on to a
portable cassette recorder.)
Mains adaptor of 600 mA
at 9VDC nominal
unregulated.
FREE course in BASIC
programming and user
manual.
JOIN THE REVOLUTION - DON'T GET LEFT
BEHIND - ORDER YOUR MICROACE NOW!!
Send Check, Money Order or quote your Credit Card No. to:
MicroAce 1348 East Edinger, Santa Ana, California, Zip Code 92705.
or phone (714) 547 2526 quoting your Credit Card Number.
Quantity
Description
TOTAL
MicroAce Kit IK
$149.00
MicroAce Kit 2K
$169.00
Manual
$10.00
1K Upgrade Kit
$29.00
Shipmen
add 6%
ts inside California
TAX
TOTAL
Amex.
Diners
Check
Money Order
Master Charge
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Card No..
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Address-
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.Zip.
Circle 121 on inquiry card.
BYTE January 1981 195
6809
SOFTWARE
POWER TOOLS
BY MICROWARE"
OS-9 ™ MULTIPROGRAMMING
OPERATING SYSTEM
j\ true multitasking, real time operating system for
J M timesharing, software development, database,
X JL process control, and other general applications.
This versatile OS runs on almost any 6809-based computer.
■ UNIX™ -like file system with hierarchical directories,
byte-addressable random-access files, and full file security.
Versatile, easy-to-use input/output system is hardware in-
dependent and expandable.
■ Powerful "shell" command interpreter features: I/O
redirection, multiple job stream processing, and more. In-
cludes a complete set of utility commands.
■ OS-9 Level Two uses hardware memory management
and can address over one megabyte of memory. Also
includes pipes and filters for inter-process data transfers.
■ OS-9 Level One runs on systems without memory
management hardware having up to 56K memory.
□ OS-9 Level Two $495* □ Level One $150'
BASIC09™ PROGRAMMING
LANGUAGE SYSTEM
Extended BASIC language compiler/interpreter with
integrated text editor and debug package. Runs
standard BASIC programs or minimally-modified
PASCAL programs.
■ Permits multiple named program modules having local
variables and identifiers. Modules are reentrant, position
independent and ROMable.
■ Additional control statements for structured
programming: IF . . . THEN . . . ELSE, FOR . . . NEXT,
REPEAT . . . UNTIL, WHILE ... DO, LOOP . . . ENDLOOP,
EXITIF . . . ENDEXIT.
■ Allows user-defined data types and complex data
structures. Five built-in data types: byte, integer,
9 digit floating-point, string and boolean.
■ Runs under OS-9'" Level One or Level Two. D$195*
OTHER OS-9™ FAMILY SOFTWARE
■ Microsoft BASIC ■ Interactive Assembler
■ Macro Text Editor ■ Interactive Debugger
■ Stylograph™ Screen-Oriented Word Processor
BASIC09 is a trademark of Motorola, OS-9 is a trademark of Motorola and
Microware'" . UNIX is a trademark of Bell Laboratories. * Most software is
available on ROM, diskette and tape in versions for many popular 6809
computers. Contact Microware® for specific availability.
MICROWARG®
Microware Systems Corp., Dept. B2
5835 Grand Avenue, Des Moines, Iowa 50304
(515) 279-8844
Languages Forum.
At the start of a FOR loop, certain information is
stacked; upon normal exit from that loop, it is unstacked.
Upon abnormal exit from a loop, the information is also
supposed to be unstacked, but in most cases it does not
matter whether the information is unstacked or not. In
this case, however, it appears to matter. The sequence of
events is as follows:
• At statement 50, we enter a loop, and C is stacked.
Clearly, the loop-index-variable name must be stacked,
along with other information that we shall ignore for the
moment.
• At statement 70, we make a normal loop exit, and C is
unstacked, leaving the stack empty.
• At statement 80, we enter another loop, and C is
stacked again.
• At statement 90, if we make the abnormal exit from this
loop, C is supposed to be unstacked; but let us assume for
the moment that it is not.
• At statement 140, we enter another loop, and R is
stacked.
• At statement 150, we enter a third loop, and C is again
stacked. Note that we are now in two loops, although the
system thinks that we are in three.
• At statement 170, we exit from a loop, and C is
unstacked. But C is on the stack twice. Which version of
C is unstacked? It must be the one at the bottom of the
stack, because, according to our analysis, when we get to
statement 180, the stack is empty. Then we try to unstack
an entry, and, since it is empty, we signal an error.
This gives a clue to fixing the bug in an imaginative
way. Of course, one way of fixing the bug is to simply
keep the relevant FOR... NEXT pairing operation around
at run time. But a simple change in the handling of NEXT
statements would also fix the bug in this case. We must
search the stack for the right information to unstack, and
the trick is to search the stack downwards from the top,
rather than upwards from the bottom. If we had done
this, we would have unstacked the right version of C, and
the bug would not have occurred.
Are there any other ill effects from leaving extra infor-
mation on the stack that should be unstacked, as is done
by those systems that have the bug? At the end of the ex-
ecution of the program, the stack will not be empty.
Since this could also happen if there were a FOR state-
ment in the program without a corresponding NEXT, this
indication might be given (erroneously) at the end of the
run. (The Data General D2 microcomputer system ap-
pears to exhibit this behavior.) Another possible un-
wanted effect is unlimited stack growth, causing stack
overflow. If an abnormal exit causing extraneous stack
information is inside an outer loop, then unwanted stack
information can continue to pile up — eventually resulting
in overflow. This situation is more serious on a
Z80-based system than on a 6502-based system, since the
stack on the 6502 is confined to hexadecimal addresses
0100 thru 01FF, and it wraps around when it overflows.
In conclusion, let it be carefully noted — as is necessary
in this fast-changing field— that all the information in this
article is as of November 12 and 13, 1980. ■
196 January 1981 © BYTE Publications Inc
Circle 122 on inquiry card.
MODEL
$ DISCOUNT $
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26-4160 1 Drive EXP .$1035.00
26-4161 2 Drive EXP .. 1575.00
26-4162 3 Drive EXP ..2115.00
26-4501 Gen. Ledger . . . 180.00
26-4502 Inventory 180.00
26-4503 Payroll 360.00
26-4554 Aect. Rec 180.00
26-4701 Fortran 270.00
26-1 157 A Daisy Wheel . 2495.00
26-1158 Daily Wheel II 1799.00
COMPUTER SPECIALISTS
26-1 155 Quick Printer II $187.00
26-1145 RS-232 Board 84.00
26-1 140 "O" K Interface 249.00
26-1141 "16" K Interface 359,00
26-1142 "32" K Interface 469.00
26-1 160 Mini Disk ■ Drive 419,00
26-1 161 Mini Disk - Additional 419,00
26-1 154 Lineprinter II 699.00
26-1 156 Lineprinter III 1799.00
26-1 159 Lineprinter IV 859.00
26-1 166 Line Printer VI 1080.00
26-1563 Scripsit • Disk 79.00
26-1566 Visicalc 83.00
26-1562 Profile 72.00
NOTE: Call for availability of VIDEO TEX, Model III, Color,
and other new products,
26-1061 4K I
26-1062 16K III..,
26-1063 32K III
2-Drives, RS232. .
. $630.00
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COLOR
ALL OTHER R.S. SOFTWARE
FURNITURE, STANDS, CABLES
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CATALOG PRICE.
26-3001 4K $360.00
26-3002 16K 540.00
26-3010 Color Video 360.00
26-1206 Recorder 54,00
26-3008 Joysticks 22.50
CEnTRonics
Fast 100 CPS Centronics
730 Printer $659.00
Text Quality Centronics
737 Printer $819,00
Novation Cat Modem. .$149.00
CCA Data Management
System 72.00
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Cobol Run Time Package
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GAMES:
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26-3503 Cassette l/F 45.00
14-812 Recorder 72.00
FREE: COMPUTER CATALOG
UPON REQUEST
1-800-841-0860 Toll Free Order Entry
MICRO MANAGEMENT SYSTEMS, INC.
No Taxes on Out Of
State Shipments
Immediate Shipment
From Stock on Most Items
DOWNTOWN PLAZA SHOPPING CENTER
115CSECONDAVE.S.W.
CAIRO, GEORGIA31728
(912) 377-7120 Go. Phone No.
'TRS.ftO If a ragiltarad trademark of tha Tandy Cora.
R.S. 90 Day Limited Warranty
F-48 Form Provided
Largest Inventory
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Circle 123 on Inquiry card.
BYTE January 1981 197
WE SUPPORT THE BUS OF THE FUTURE:
S-100 systems are ideal for high level industrial, commercial, and scientific applications.
Modularity prevents obsolescence; conformance to the IEEE 696/S-100 standards assures well- integrated system performance.
Find out what a computer can really do . . . specify CompuPro and the S-100 bus.
NEW: "SYSTEM SUPPORT 1"
S-100 MULTIFUNCTION BOARD
$295unkit, $395 assm, $495 CSC
Finally — one multi-purpose board combines all the most useful system
support funclions required by your computer. Extensive use of LSI
technology not only packs the greatest number of features in the minimum
amount of space, but also increases reliability and cuts costs compared lo
buying numerous single-function boards. Features include:
— Sockets for 4K of extended address EPROM or RAM (271G pinoul)
— Crystal controlled month/day/year/lime clock
— Optional high speed math processor (951 1 or 9512)
— Full KS-232 serial port
— Three 16 bit interval timers (cascade or use independently)
— 15 levels of vectored interrupts
— Conforms fully to all IEEE 696/S-100 standards
Ready to add some extra performance to your S-100 system? Then this is
the board for you. System Support 1 comes with a comprehensive owner's
manual that includes numerous software examples; add $195 to Ihe above
prices for the optional 9512 math processor.
COMPUPRO S-100 MOTHERBOARDS:
DESIGNED FOR THE FUTURE,
AVAILABLE NOW
Fully terminated and fully shielded, these advanced motherboards handle
the coming generation of 5 to 10 MHz CPUs as well as present day 2 and 4
MHz systems. Mechanically compatible with most computer enclosures.
Unkits have edge connectors and termination resistors pre-soldered in plane
for easy assembly.
20 slot motherboard with edge connectors — unkit $174, assm $214
12 slot motherboard with edge connectors — unkit $129, assm $169
6 slot motherboard with edge connectors — unkit $89, assm $129
CPU Z: 8 BITS OF Z80*
POWER FOR THE S-100 BUS
Like many others, we claim full conformance lo IEEE 696/S-100 specifica-
tions; unlike many others, we'll send you the timing specs to prove it. CPU Z
includes all standard Z-80A* features along with power on jump, on-
board fully maskable interrupts for inlerrupl-driven systems, selectable
automatic wait stale insertion, provision Tor adding up to 8K of on-board
EPROM, and 16/24 bit extended addressing. Works with 6 Mil/. CPUs; sup-
plied with 4 MHz CPU. $225 unkit, S295 assm, $395 CSC.
8088/8086 MONITOR-DEBUGGER: $35
Supplied on single sided, single density, soft-sector 8" disc. CP/M* com-
patible. Great development tool: mnemonics used in debug conform as closely
as possible to current CP/M* DDT mnemonics.
COMPUPRO COMPUTER ENCLOSURE
$289 desktop, $329 rack mount
This enclosure does justice to the finest computer systems. Includes dual
AC outlets and Tuseholder on rear, heavy-duty line filter, quiet ventilation
fan, and black anodized front panel (with textured vinyl painted cover for
desktop version). Pro-drilled base accepts our high-performance S-100
motherboards or types by Vector, California Digital, and others. Rack mount
version includes slides for easy pull-out from rack for maintenance or board
changing.
PASCAL/M* FROM SORCIM: $175
PASCAL — easy lo learn, easy to apply — can give a microcomputer with
CP/M* more power than many minis. We supply a totally standard Wirth
PASCAL/M* 8" diskette and comprehensive manual. Specify Z-80* or
8080/8085 version.
CompuPro products nrt: available in unkit form, assembled, or qualified undor the high- ■
J reliability Certified Sysli;m Component (CSC] [mi^nim (200 hour burn-in. oxlmisivo testing, !
I extended 2 yonr warranty, moro), Please note lhal unkils are not inlendud for novices, as j
I de-bugging may bo roquirod duo lo problems such as IC infant mortality, factory sorvioo isj
I available for unkits tit u fhii Bervice Charge '
I _____ ______!
LOWEST PRICE EVER !!
16K DYNAMIC RAMS — 8i$37
lust what you would expect from the memory leader: the lowest price
ever on 16K dynamic RAMs, backed up with a 1 year warranty. These are
lop quality, low power, high speed (200 ns) parts that expand memory in
TRS-80* -I and -II computers as well as machines made by Apple. Exidy,
Heath H89. newer PETs, etc. Add $3 for two dip shunts plus TRS-80* con-
version instructions. Hurry! 16K dynamic RAM prices may never be this low
again, and quantities are limited.
CPU 8085/88: 16 BIT DUAL PROCESSING
POWER FOR THE S-100 BUS
When we shipped Ihe first CPU 8085/88 board back in June of 1980. we
created ;i bridge between the 8 bit world of the present and Ihe 16 bit world
of the future. By using an 8088 CPU (for 16 bit power with a standard 8 bit
bus) in conjunction with an 8 bit 8085. CPU 8085/88 is downward compatible;
with 8080/8085 software, upward compatible with 8086/88 software (as well
as Intel's coming P-Series), designed for professional-level high speed ap-
plications, and capable of accessing 16 megabytes of memory . . . while con-
forming fully to all IEEE 696/S-100 standards (timing specs available on re-
quest).
booking for a powerful 8 bit CPU board? Looking for a powerful 16 bit
CPU board? Then look at CPU 8085/88, the best of both worlds.
Prices: $295 unkit, $425 assm (both operate at 5 MHz); $525 CSC (with 5
MHz 8085. 6 MHz 8088). Owner's manual available separately for $5.
Also available: CPU 8085 (single 8 bit processor version of above) Tor $235
unkit, $325 assm, $425 CSC.
2102 MEMORY SPECIAL
While they last 99 cents each. 10/$9.90. Low power.
CLOSEOUT SPECIAL: 32K fully static memory for the SBC bus
(RAM XI), now only $699 assembled. Limited quantities.
OTHER S-100 BUS PRODUCTS
Active Terminator Board $34.50 kit
Memory Manager Board $59 unkit, $85 assm, $100 CSC
Mullen Extender Board $59 kit
Mullen Relay/Opto-Isolator Control Board. .$129 kit, $179 assm
Spectrum color graphics board $299 unkit, $399 assm, $449 CSC
2708 EPROM Board (2708s not included). . .$85 unkit, $135 assm, $195 CSC
Interfacer 1 (dual RS-232 serial ports) $199 unkit, $249 assm, $324 CSC
Interfacer 2 (3 parallel + 1 serial port) $199 unkit, $249 assm, $324 CSC
COMING SOON: "MPX 1", a front end processor/system
multiplexer for high speed multi-task/multiuser setups. Greatly
enhances multiuser performance by taking over system I/O
overhead from the main CPU. Included on board: 5 MHz 8085
microprocessor, 2K of ROM, 4K of RAM, interrupt controller, and
much more. Finally . . . multi-processing is an affordable reality.
Also, if you've been waiting for someone to do a dual density
disk controller board right . . . your patience has been rewarded.
The CompuPro disk controller is on its way.
TERMS! till rim mill lux. Allow m lensl .v.. shipping oxnotil, 1-nHiniltxl. Ontors onilorsl5 ntld S3 hlMUUing. VISA'
/Mnsloroortl" onlors |S25 rain] Will [4181 5fi2-Hli:ili. 24 hrs. 1'Iiiomi; inolmlo slrool mhlrrss for UTS dalivory. Ppfeua
itnl suli|ool lo i:lmiii!0 wlltl'llll rojllfit).
FREE CATALOG: find mil more about the CompuPro product linn, and bow il can turn your
computer into a powerful Information processing tool, l-or 1st dnss delivery, add 41 oonts
in slumps: Fnrnijpi orders unit $2 (rnfundobli: with order).
LEGAL CORNER: KHUA Ikii ,.-ui-I.T-->1 1r.ul.-ni.irk >il Zihi W ; I KSIIII i. .1 lr.nl. nurL ,.l Hoi I. unit Ifcrnifl I'ASIIAI.M w .1 IMiliKiori ..I >,,.n im. i:i- M r»
COMPUPRO PRODUCTS ARE AVAILABLE AT FINER COMPUTER STORES WORLD-WIDE
OR DIRECT FROM THE FACTORY.
CompuPro
OAKLAND AIRPORT, CA 94614
from pt50S®ll(£
v ^ ELECTRONICS ^
198 BYTE January 1981
Circle 125 on inquiry card.
Memory has assumed tremendous importance in today's
computers, which is why you don't just need memory: you
need reliable, finely-tuned, precision machines.
We've understood the importance of memory since we
introduced our first memory board well over 5 years ago.
That's why CompuPro memory conforms fully to all IEEE
696/S-100 specifications . . . uses low power static
technology to avoid dynamic timing problems . . . comes in a
choice of formats (unkit, assembled , or qualified
under the Certified System Component high-
reliability program) . . . and zips along to keep your
throughput up where it should be (10 MHz
operation with CSC and assembled boards, 5 MHz
with unkit boards). We back these precision
machines with a standard 1 year warranty, and 2
year extended warranty for CSC boards.
RAM memory machines from
CompuPro couple experience,
innovative engineering, and
cost-effectiveness.
See them in person at finer
computer stores world-wide.
CompuPro
OAKLAND AIRPORT, CA 94614
from
iijl®lB6)
W* ELECTRONICS ^
Prices (assembled and tested units]: 8K RAM 2A,
$189; 16K RAM 14*, $349; 16K RAM 20-16**,
$399; 24K RAM 20-24**, $539; 32K RAM 20-32**
$699. Write for prices on unkits and CSC
boards. 128K RAM 21-128* (CSC only), $2795.
Also available in 64K and 96K configurations.
For 24 hour VISA* /Mastercard® orders,
call (415) 562-0636.
•With IEEE extended addressing
**Uso with IEEE ox tended addressing systems o
BYTELINES
News and Speculation About Personal Computing
Conducted by Sol Libes
*» upercond uctlvl ty At
Room Temperatures
Reported: A breakthrough
for the next generation of
supercomputers may have
been made. It was previous-
ly thought that superfast
computers, using Josephson
junctions, would require
supercooling to a tempera-
ture near absolute zero.
Now, Fred W Vahldiek of the
Wright-Patterson Air Force
Base, Dayton, Ohio reports
that he has achieved super-
conductivity at room tem-
peratures. Vahldiek has
developed titanium borite
crystals with zero resistance.
Further research will be
required to determine
whether or not this could
lead to the development of
computers with picosecond
machine cycles and 100%
power efficiency.
I
BM Announces 370-
On-A-Chlp: IBM has dis-
closed what many already
suspected: it has implement-
ed the circuitry of a model
370 processor on a single in-
tegrated circuit. IBM has
created a 370 model 1 38 pro-
cessor that utilizes 5000 cir-
cuits and Schottky-clamped
bipolar TTL (transistor-tran-
sistor logic) technology that
can execute 2000 instruc-
tions per second. The device
has a cycle time of only 100
ns and consumes 2.3 watts.
It is part of a research pro-
ject, and no specific plans
for a product have been an-
nounced.
I™ ight For 16-Bit Micro-
processor Market: It ap-
pears that the 16-bit micro-
processor market is the
scene of a three-way battle
between the Motorola
68000, the Zilog Z8000, and
the Intel 8086. Although the
68000 is ranked first in per-
formance and the 8086 is
ranked last, the volume of
sales is greater for the 8086.
Intel has a two-year lead in
product availability. This
means that there is already a
substantial software base
and peripheral device sup-
port. Furthermore, Intel has
introduced 8086 enhance-
ments such as a 10 MHz ver-
sion, an arithmetic co-pro-
cessor, and a new 32-bit mi-
croprocessor, the iAPX-432,
that may undercut the 68000
and Z8000. Intel expects to
start shipping samples of the
iAPX-432 in two or three
months.
u,
'NIX-LIke Operating
Systems Increasing In
Popularity: Several soft-
ware suppliers are now offer-
ing UNIX-like operating sys-
tems that may rival CP/M.
The first UNIX-like software
package, called TYNIX, was
released for LSI-11 and
Heath H-11 systems in 1978
by the Boston Children's
Museum. In 1979, Yourdon
announced OMNIX for Z80
computers and advertised it
as CP/M compatible and
similar to UNIX. Yourdon
then withdrew it because of
software bugs, but it may be
released again. Whitesmiths
released its IDRIS system in
early 1980. Also in 1980,
ElectroLabs introduced its
OS-1 UNIX-like system (now
marketed by Software Labs),
and late last year Microsoft
and Morrow Designs an-
nounced packages for Z8000
and Z80 systems, respective-
ly.
^■opyrlght Decision
Overturned: In Chicago,
the US Court of Appeals has
overturned an earlier ruling
that ROM- (read-only mem-
ory) based software cannot
be copyrighted. In the case
of Datacash vs JS & A (as
reported earlier in this col-
umn), the court had ruled
that the marketing of a chess
game by JS & A with a pro-
gram identical to the one
originally developed by
Datacash was not copyright
infringement because under
the 1909 copyright law the
program could not be read
with the naked eye.
E thernet Specifica-
tions Released: Xerox,
Digital Equipment, and Intel
have published specifica-
tions for the Ethernet system
developed by Xerox. Ether-
net provides a local net-
working system for word and
data processing applica-
tions. Xerox has already
released some Ethernet
products.
Ethernet is a passive sys-
tem and does not use switch-
ing logic or a central com-
puter. Rather, coaxial cable
and communications trans-
ceivers attach each machine
to the network; each ma-
chine is assigned a 48-bit ad-
dress. Data is transferred in
serial groups which include
the data and the addresses
of both the sender and the
addressee. Each transceiver
monitors the cable for data
with its address. It is ex-
pected that the IEEE (In-
stitute of Electrical and Elec-
tronics Engineers) will in-
tegrate the Ethernet specifi-
cations into the networking
standard currently in devel-
opment.
Amda Language Final-
ized And The Rush Is
On: Ada, the language that
the DOD (Department of
Defense) expects to even-
tually replace all other
languages, has been final-
ized, according to Jean Ich-
biah, president of Apsys,
Washington DC. Over nine
hundred revision proposals
were submitted, and several
major improvements have
been incorporated into the
proposed Ada language
standard that was released
in 1979. The most significant
improvement is the addition
of tasking. The Ada Refer-
ence Manual may be obtain-
ed from the DOD's DARPA
office, 1400 Wilson Blvd,
Arlington VA 22209.
At least twenty-five com-
panies and universities are
reported to be in the process
of developing compilers for
the Ada language. A few uni-
versities have already had
their Ada compilers running.
However, the first commer-
cial release has yet to occur,
Intel claims that its new
32-bit microprocessor, due
for release shortly, will use
Ada as its primary language.
WD (Western Digital) is
rumored to be working on a
single-board Ada computer
that is similar to its Pascal
MicroEngine. WD has pur-
chased a 20% interest in
Telesoftware Inc of San
Diego, which is developing
an Ada compiler. (Dr Ken-
neth Bowles of UCSD Pascal
fame owns an additional
40% interest in the com-
pany.) Reportedly, Telesoft-
ware already has a prelimin-
ary version of its Ada com-
piler running.
WP/M For 8086/8088
Systems Released: Digital
Research has released CP/
M-86. This operating system
is designed for 8086- and
8088-based systems and pro-
vides the same facilities and
file format as CP/M, release
2. CP/M-86 can also function
as a slave node in a CP/NET
network. As with 8080-based
versions of CP/M, the logic-
and hardware-dependent
portions of CP/M-86 are
modularized for ease of cus-
tomization. Digital Research
also plans to release MP/M
and PL/I for 8086/8088-based
systems in the near future.
I ontgomery Ward
And Sears Expand Per-
sonal Computer Market-
ing: After test marketing
Ohio Scientific computers in
selected stores, Montgom-
200 January 1981 © BYTE Publications Inc
90S
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Report Writer
is a trademark of Carolina Business Computers
Selector IV Is a trademark of Micro-Ap Pearl is o
trademark of CPU International Pascal/M, ACT & TRANS 86 are
trademarks of Sorcim CBASIC2 is a trademark of Compiler Systems
Magic Wand is a trademark of Small Business Applications Textwiter, Datebook &
Milestone are trademarks of Organic Software Ultrasort-ll is a trademark of Computer Control Systems
For shipping add S5
Circle 126 on inquiry card.
Magic Menu is o trademark of Charles Merrift Copywriter is a trademark of Systronics Mlcrostat is a trademark of Ecosoft
S-Basic is a trademark of Topaz Programming CP/M & MP/M are trademarks of Digital Research TRS-80 is a trademark of Tandy
Superbrain is a trademark of Intertec Data Systems UCSD Pascal is a trademark of the Regents of the University of California
in US- S10 outside US per package California residents add appropriate state sales tax Terms: Prepaid check, M/C or VISA
or in US COD (UPS) Dealer inquiries invited Prices effective until March 1, 1981
BYTE January 1981 201
BYTELINES
ery Ward has decided to ex-
pand its personal computer
sales into one hundred
stores. The stores will sell
the OSI Challenger 1P and
4P cassette-based systems
with accessories such as disk
drives, video monitors, print-
ers, security systems, and
software. Sears is now carry-
ing two full pages in its
catalog promoting the Atari
400 and 800 computers,
games software packs, and
peripherals. Other retail
chains and department
stores are expected to follow
in their footsteps.
Jystem Puts Local Net-
work On Cable TV: Sytek
Inc, Sunnyvale, California
has introduced a packet-
network system to support
up to 24,000 terminals and
operate at up to 9600 bps
(bits per second) over a
cable TV system. This sys-
tem, called "LocalNet," is
expected to fill the gap that
exists between such systems
as Ethernet and ARPANET.
Ethernet is limited to a 1 to 2
km distance while ARPANET
is committed to long-dis-
tance distributed processing.
LocalNet can cover up to 50
km distances on a single
coaxial cable and can be
piggybacked onto existing
CATV cable systems, thus
providing a very low-cost
networking system.
IM,
I EC Claims Cure For
Dual-Sided Floppy Prob-
lems: NEC, the Japanese
manufacturer, claims to
have developed a floppy
disk system which elimi-
nates the disk and head wear
problems associated with
dual-sided floppy disks. NEC
uses an "air" shock absorber
to cushion the force of the
heads landing on the disk,
and the company claims
that its new FD1160 Soft
Touch drive provides twice
the media and head life of
competitive drives.
Standard For 32-Blt
Bus: The IEEE has formed a
committee to draft a back-
plane bus standard, desig-
nated as P896, for 32-bit
microcomputers. According
to committee chairman An-
drew Wilson, P896 is already
well along in development,
and a draft may be released
soon. The bus will support
32-bit microprocessors un-
der development by Intel
and other companies. It will
be processor-independent
and will support up to sixty-
four bus masters and clock
rates of up to 20 MHz.
fcSOOO Call Conven-
tions Proposed: Micro-
soft, Bellevue, Washington
(the largest supplier of mi-
crocomputer software) has
proposed a standard for
Z8000 calls that specify
parameter-passing and regis-
ter usage. Adoption of a
standard would enable
Z8000 languages, applica-
tion programs, and operat-
ing systems to be more easi-
ly interfaced, and would fa-
cilitate the building of a
Z8000 program library simi-
lar to the present CP/M User
Group Library.
mJ o Computers Cause
Unemployment? Calvin C
Cotlieb, a professor of Com-
puter Science at the Univer-
sity of Toronto, delivered a
paper at the recent IFIPS (In-
ternational Federation of In-
formation Processing Soci-
eties, Inc) Congress-80 which
claimed that computers are
causing unemployment.
Gotlieb cited dozens of stud-
ies to support his claim; for
example, at one Western
Electric facility, the number
of employees was reduced
by 50% (from 39,200 to
19,000) over a six-year peri-
od, while production doub-
led. A Japanese TV manu-
facturer increased produc-
tion by 25% over a four-year
period, while reducing the
number of workers by 50%.
Cotlieb contends that com-
puters must be used more
wisely, and cited a West Ger-
man study that stated:
"(C)omputers make things
more formal, more routine,
more bureaucratic and inev-
itably lead to less humane
treatment of people." He
also cited a law on the West
German books that com-
plains: "(O)nce a decision is
made by a computer, no one
is permitted to challenge it,"
Atmateur Robotics On
The Rise: More and more
hobbyists are building their
own robots. The evidence is
the fact that there are al-
ready several companies
supplying robot parts to hob-
byists and two magazines
catering to their interests.
Hobbyists seeking parts and
kits should write to: Hobby
Robotics Company, POB
997, Liburn CA 30247, and
the Robot Mart, 19 W 34th
St, New York NY 10001.
Robot Mart also publishes
the Hobby Robot Newslet-
ter.
■ lat-Panel Display
Technology Improving:
Although CRTs (cathode-ray
tubes) still dominate the
computer-terminal display
field, it appears that several
flat-screen systems will soon
be ready to challenge that
dominance. The new tech-
nologies include electro-
phoretic, electrochromic,
LCD (liquid-crystal display)
and LED (light-emitting
diode) systems. LCD panels
are already available in
1-and 2-line versions. Several
firms will soon offer multi-
line panels. Dot-matrix dis-
plays are also under devel-
opment by several firms,
and prototypes are becom-
ing available in LED, vacu-
um fluorescent, and elec-
troluminescent technolo-
gies. There is no doubt that
flat-screen terminals will
compete with small CRTs
within two or three years.
One manufacturer of flat
screens is Optotek Ltd, of
Ottawa, Canada, which will
soon offer a display using
LEDs that are 1/8000 inch in
diameter. Each square inch
of the display has 4000
diodes. A 3- by 4-inch display
has 49,000 diodes. Control of
the diodes is performed by
special VLSI (very large-
scale integration) integrated
circuits provided for each
square-inch block.
R
andom Bits: As of
January 1, 1981, Radio
Shack has stopped produc-
tion of the TRS-80 Model I
computer, in anticipation of
increased sales of the
TRS-80 Model III. .The IEEE
has established a committee
to develop a standard for
benchmark programs for
microprocessor users...
Several hundred workers at
the Minneapolis Star and
Tribune newspaper recently
went on strike tc protest,
among other things, the
newspaper's experimental
electronic newspaper pro-
ject with CompuServe Inc....
Japan's NTT (Nippon Tele-
graph and Telephone Public
Corporation) will soon in-
augurate a public facimile
network that may be the first
step in developing an elec-
tronic mail system. ...Intel
has released prices on its
new 2764 64-K-bit (16K by 8
bits) 250ns EPROM: $163
each in lots of one
hundred. ...Seventy to eighty
percent of all TRS-80 Model
II systems are running CP/M;
this statement is based on
the fact that Lifeboat
Associates has already sold
4000 copies of CP/M for the
Model II.
R
l andom Rumors: Ap-
ple Computer Company may
be setting up its own floppy-
disk manufacturing opera-
tion to make double-sided
double-density drives for its
new Apple III Computer. In-
troduction of the drive is ex-
pected by mid-year....
Sources say that Radio
Shack is close to releasing a
hard-disk drive for the
TRS-80 Model II and III com-
puters. Further, Radio Shack
will soon release version 1.3
of its DOS (disk-operating
system) to replace version
1.2 which, reportedly, has
many bugs. Unfortunately,
the two versions will not be
compatible. ...Altos Com-
puters is said to have switch-
ed from the Z8000 to the
8086 for its new 16-bit sys-
tem. This decision was prob-
ably due to the introduction
of the CP/M^86 from Digital
202 January 1981 © BYTE Publications Inc
Suddenly, RCA makes talking to
your computer a lot cheaper.
New interactive data terminal
with color graphics-only $36
RCA's new VP-3301 is a professional quality, ASCII
encoded, interactive data terminal, suitable for a wide
variety of industrial, educational, business and individual
applications requiring interactive communication
between computer and user. Connects directly to your
computer or to a standard modem for over the phone
access to time sharing networks and data bases. And it's
compatible with networks such as those provided by
CompuServe Information Services and Source Tele-
computing Corp. Microprocessor intelligence and LSI
video control integrated circuits bring performance,
features and flexibility at a low price. Power supply
included.
Unique color locking circuitry creates sharp, jitter
free, true color graphics and rainbow free characters.
Displays the entire field of characters in any of 8
colors against any of 8 background colors (7 gray scales
with monochrome monitors). Or to add special
emphasis, you can display individual letters, words or
lines in different colors or in reverse video.
The VP-3301 offers you a choice of two software-
selectable display formats: Either 40 characters by 24
lines. Or 20 characters by 12 lines.
The terminal's resident character set consists of 52
upper and lower case alphabetics, 1 numerals, 32
punctuation/math symbols, and 31 control characters.
You can also define a total of 128 of your own characters.
Including: Greek letters and other foreign alphabets,
graphic symbols, large graphics building blocks.playing
card suits, unique character fonts, and "little green men."
The keyboard section features flexible-membrane
key switches with contact life rated at greater than five
million operations. A finger positioning overlay and
positive keypress action give good operator "feel".
An on-board sound generator and speaker provides
aural feedback for key presses and may also be
activated with escape sequences to provide an audio
output.
The sealed keyboard surface is spill proof and dust
proof. This combined with high noise immunity CMOS
circuitry makes the VP-3301 ideal for hostile
environments.
Output is industry standard asynchronous RS232C
or 20 mA current loop with six switch selectable baud
rates and 8 selectable data formats.
The terminal can be connected directly to a 525 line
color or monochrome monitor. Or to a standard TV set
using an Rf modulator.
For more information, contact RCA Microcomputer
Marketing, New Holland Avenue, Lancaster, PA 17604.
Or call our toll-free number: 800-233-0094.
'Suggested user price.
RC/1
Circle 127 on inquiry card.
BYTE January 1981
203
BYTELINES
Research. ..North Star Com-
puters might be developing
a single-board 8088-based
system that will work with a
hard disk and support CP/M
....Whitesmiths Ltd is ru-
mored to be about to release
an 8088/8086 version of its
C compiler.... A California
firm may be readying an
under $300 OEM (original
equipment manufacturer)
daisywheel printer that
would be set for introduc-
tion by the end of the year.
I redlctlons. Predic-
tions.. .In my December
1979 column I made eleven
predictions for 1980. Several
readers asked me to grade
myself on how well I did, so
here goes:
1 . The first Japanese per-
sonal computer system will
become available in this
country. Score a "correct."
In fact, several have been in-
troduced and reported on in
this column. Look for many
more in 1981.
2. Competitive pressures on
small manufacturers will in-
crease. This will cause
several mergers, consolida-
tions or acquisitions. Score a
"correct" on this one too. So
many failures, mergers and
acquisitions occurred that
they are too numerous to be
mentioned. More will be
forthcoming in 1981.
3. A sizable number of audio
and office equipment re-
tailers will enter the com-
puter retailing business. This
will create pressures on con-
ventional computer stores.
We may even see the ap-
pearance of stores that sell
only software, much like
audio record stores. Score a
"maybe." Although some
steps have been taken in this
direction (eg: Bell & Howell
and several other audio/
visual and office equipment
suppliers), the real first step
has yet to be taken. ..possible
developments this year or
next.
4. 16-bit microcomputer
systems will be common-
place. Score a "maybe" on
this one too. Although
several 16-bit systems were
introduced, lack of 16-bit
parts and software limited
their adoption. We should
see a significant increase in
their acceptance in 1981
with the availability of
CP/M, MP/M, UNIX and
other powerful operating
systems.
5. IBM, DEC, Data General,
H-P and other minicomputer
makers will introduce low-
cost microcomputer systems.
Score a "partial" on this one,
as H-P (Hewlett-Packard) in-
troduced the HP-85 and IBM
showed its S-100 product in
Europe but withheld it from
the US market. These com-
panies may jump in this year
or next.
6. Several personal com-
puter manufacturers will in-
troduce second-generation
machines with significant in-
creases in power. Score a
"no." Although Apple,
Tandy and Commodore all
introduced new machines,
none were significantly dif-
ferent from their previous
units. I look to 1981 for the
introduction of a machine
with significantly new per-
formance versus price mark.
7. The emphasis will shift
from hardware to software.
BASIC will continue as the
dominant language. Score
another "correct." This year
should see continued im-
provements in disk operat-
ing systems and applications
packages.
8. Business application soft-
ware for microcomputer sys-
tems will finally come of age
and provide the needed per-
formance that suppliers have
been promising but not de-
livering during the past two
years. Score a "correct."
9. The first low-cost micro-
computer-based robot kit
will be introduced. Score an
"incorrect." Although a
robotic arm kit was intro-
duced, its price was beyond
the means of most personal
computerists. Maybe this
prediction will come true in
1981.
10. Typewriters will have
built-in intelligence, and use
microprocessors, built-in
microdisks, and word pro-
cessing features. The dumb
typewriter will soon be a
thing of the past. Score an
"incorrect." Although Smith-
Corona and Triumph-Adler
introduced electronic type-
writers, their intelligence is
still on a primitive level. I
am now projecting 1982 or
1983 on this development.
11. Personal computer time-
sharing systems will pro-
liferate. Score a definite
"correct" on this one.
All in all, I would rate my
prediction ability as "fair":
about sixty points out of a
possible one hundred.
Where I guessed wrong I was
just ahead of the industry.
I redlctlons For The
Future: Not allowing my
previous performance to
deter me, I will venture forth
with some more predictions:
1. The S-100 will become
the de facto standard for bus
interfacing. There are al-
ready thirty-two manufac-
turers of S-100 systems, and I
expect this number to in-
crease to over forty in 1981
(and to include IBM). This
trend should continue into
the mid-1980s, when we may
see the development of a
new interface bus to accom-
modate new hardware and
architectures.
2. Hardware will become
more sophisticated and less
expensive. This is not a dif-
ficult prediction to make,
since Moore's law states that
"the number of components
per integrated circuit rough-
ly doubles every year."
Thus, personal computer
systems will acquire the
characteristics of their larg-
er, more expensive predeces-
sors. In other words, within
three to five years we can ex-
pect personal computers
with the characteristics of
large IBM 370s. The likeli-
hood is that by the mid-
1980s we will see a single
package device containing
processor, floating-point
arithmetic, main memory
and read-only memory with
the complete operating sys-
tem and a compiler or inter-
preter.
3. The man-machine inter-
face will improve to accom-
modate the many users who
have little or no knowledge
of computers. I therefore
look for voice input/output
to become commonplace by
the end of the decade. Al-
though voice input may be
limited to short commands,
output should be of a high
quality with a large vocabu-
lary.
4. Cheap mass storage will
finally arrive via video
cassette and optical disk
memories. We will be able
to store 100,000 pages of
printed text on a single op-
tical (video) disk. ..expect to
see the Encyclopaedia Bri-
tannica on a single optical
disk, with sophisticated
cross-referencing software.
Furthermore, expect optical
disks that may be used with
personal computers to pro-
vide high-quality video im-
ages for games, educational
use, etc.
5. Higher-quality displays
using either liquid crystal or
semiconductor technology
will replace CRTs (cathode-
ray tubes).
6. Personal computers will
include self-testing capa-
bilities and redundant cir-
cuits to improve reliability.
7. Expect BASIC to continue
as the dominant language.
Assembler and Pascal will
still be the most popular
languages for systems-level
programming, and C will in-
crease in popularity. Natural
programming languages and
automatic programming still
appear to be many years
away. The number of menu-
driven systems for the naive
user will increase.
8. Operating systems such
as UNIX, CP/M, MP/M and
more sophisticated systems
will increase in popularity,
and many manufacturers
will design special hardware
to support these operating
systems.
MAIL: I receive a large num-
ber of letters each month as a
result of this column. If you
write to me and wish a re-
sponse, please include a
stamped, self-addressed enve-
lope.
Sol Libes
POB 1 1 92
Mountainside NJ 07092
204 January 1981 © BYTE Publications Inc
The
I
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BYTE January 1981 207
Product Review
The Newest Sargon — 2.5
John Martellaro
2929 Los Amigos Ct Apt B
Las Cruces NM 88001
Time travel is common now. You've decided to spend
the afternoon in Vienna on a sunny spring day in 1770.
There is talk that at the Royal Palace the Baron Wolfgang
von Kempelen, counselor to the Royal Chamber, will be
giving a demonstration of his amazing Automaton Chess
Player. You wander over towards the Palace.
The murmur of the crowd grows as the Baron rolls a
large wooden cabinet into the courtyard, the result of a
solemn promise he made to the Queen 6 months ago to
build a chess-playing machine. The Baron smiles gra-
ciously and invites anyone to come forward from the
crowd to play the Automaton.
Meanwhile, the noblemen are about ready to accuse
the Baron of a hoax. A machine that thinks? Rubbish.
Sacrilege. And the spectators are no more convinced.
Catcalls from the crowd dare the Baron to open the
cabinet — obviously big enough to hold a small man —
whereupon von Kempelen opens all the doors only to
reveal a complex system of pulleys, gears, and levers,
nothing else.
About this time, you decide to come forth from the
crowd to play this wondrous machine. Unknown to
everyone, you have Sargon 6, no bigger than a match-
book, hidden in your palm. With its aid, you win, but the
Automaton plays a superb game. Afterwards, a crowd
gathers around you, and the Baron congratulates you on
your game. Everyone agrees that the machine played a
creditable game of chess, clearly outplayed by a genius.
A priest overhearing this remarks that this is proof of the
superiority of the human mind. You shrug, put Sargon 6
in your pocket, and wander off into the crowd.
The Baron will go on to amaze the bewildered crowds
in Europe and America for many years, and the machine
will defeat many chess players. It will take 70 years for
the hidden compartment and the hoax to be revealed. But
the dream of a chess-playing machine is planted firmly in
the minds of men. A dream which would take another
200 years to come true.
Introduction
Sargon 6 isn't available yet, but Sargon 2.5 is. It is a
game module and holder slightly larger than a hardback
book, but the real guts are no larger than a pocket
calculator. This is the MGS (Modular Game System)
from Chafitz; as of this writing, it is the strongest chess-
playing microcomputer you can buy.
You may already be familiar with the Sargon 1 and
Sargon 2.0 computer programs written by Dan and
Kathe Spracklen. These are available on cassette or flop-
py disk (from Hayden Books) for the Apple II and
TRS-80 computers. But now Chafitz is marketing Sargon
2.5 as a plug-in ROM (read-only memory) module that
fits into the MGS. Presumably, when Sargon 3 and other
versions are available, you can remove the old ROM and
plug in the new one. Not only does this protect the firm-
ware, but allows new games (such as checkers and
backgammon) to be run on the same system.
The technical specifications of the MGS-Sargon 2.5
combination are many and impressive. The system is
rather complete: a benefit of Chafitz's previous ex-
perience with its chess machine, Boris. A touchpad
keyboard allows the user to:
• force selection of best move
• use the machine in its hint mode
• set playing level (from to 6)
• set up a given position
• show elapsed time (either player, cumulative, or time
per move)
• withdraw a move or moves (up to three moves)
Af a danrp
Name
mable memory (for inter-
Chafitz Modular Game
nal use only)
System with Sargon 2.5
Additional features
Manufacturer
Includes AC adapter,
Chafitz Inc, 856 Rockville
keyboard, chessboard,
Pike, Rockville MD
magnetized chess pieces;
20852, (301) 340-0200
Sargon 2.5 is a re-
movable module that can
Price
be replaced by other
$375
game modules (not yet
released)
Processor
6502, 8-bit
Software
Sargon 2.5 program, held
System-clock frequency
in 8 K bytes of ROM
2 MHz
Options
Memory
Rechargeable battery
2 K bytes of program-
option
208 January 1981 © BYTE Publications Inc
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DEALER INQUIRIES INVITED
Sicilian Defense
White
Black
Martellaro
Sargon 2.5 (level 4)
1 . e2-e4
c7-c5
2. Ng1-f3
d7-d6
3. Bf1-b5 ch
Bc8-d7
4. Bb5-c4
Nb8-c6
5. Nb1-c3
Ng8-f6
6. d2-d4
c5xd4
7. Nf3xd4
Qd8-b6
8. Bc1-e3
Qb6xb2??
9. Nd4-b5
Ra8-c8
10. Ra1-b1
...and Black loses his Queen
Table 1: Beginning
of a
chess game between the author and
Sargon 2.5.
The system is very nicely packaged. The quality of the
plastic case and the display is outstanding. In the instruc-
tion manual there is a brief rule description of chess and
information on the USCF (United States Chess Federa-
tion). This is an important and welcome addition.
Overall, the instructions are clear and easy to under-
stand. For once, we have complete documentation.
A conversation with Kathe Spracklen revealed that the
decision algorithms of Sargon 2.5 are exactly the same as
those of Sargon 2.0. The only modification is that the
host 6502 microprocessor runs at 2.0 MHz as opposed to
the Apple's effective 1.0 MHz, and Sargon 2.5 thinks on
its opponent's time. The result of this is that Sargon 2.5 is
often ready with a move as soon as the opponent enters
his move. The program uses 8 K bytes of ROM and 2 K
bytes of programmable memory.
Playing Strength
When chess programs were first written for microcom-
puters (Microchess 1.0 on the KIM and Sol), we all
laughed and proceeded to demolish them. While we had
respect for the programs on big computers, microcom-
puter chess programs had a poor reputation. Times have
changed, and now the average player can no longer bully
microcomputer-based chess programs. That is not to say
that Sargon can't be beaten by a good player. (Some
results are given here; see tables 1 and 2.) But now a
player must use care and caution, and a single slip can
mean disaster.
Sargon 2.5 in experimental form obtained a USCF
rating of 1641 in a rated human tournament (the 1979
Paul Masson Championship). This is not bad at all for a
machine that plays under tournament time controls and
can be held in the palm of your hand. Reportedly, the
Spracklens are working on major improvements that will
boost its rating (Sargon 3) to 1800 in tournament time.
Sargon 2.5 is probably the last microcomputer program
that we amateur players will be able to consistently beat.
Playing Results
In a match of five games between Sargon 2.5 and
Sargon 2.0 (which runs on my Apple II), the programs
split — two wins, two losses each, and a declared draw.
Sargon 2.5 started out slowly indeed. I didn't mind too
much when I (rated about 1700) and a friend (rated 1850)
210 January 1981 © BYTE Publications Inc
When it comes to 6800
Software Source Books;
Hemenway delivers what
the others leave out.
...including complete source listings,
complete descriptions of all algorithms used,
and complete manuals of the products.
SP/68 OPERATING SYSTEM STRUCTURED BASIC LANGUAGE
One of the most powerful operating systems STRUBAL+'" COMPILER
available for the 6800 family of microproces- The compiler features variable precision
sors, this disc-based system features great from 4 to 14 digits for business or scientific
flexibility. The user can add commands for uses and Structured Programming forms. It
special purposes. A single transient Periph- produces Relocatable and linkable code. You
eral Interchange Program (PIP) transfers data can create data structures with mixed data
between devices. The system is relocatable types, COMMON and DUMMY sections.
anywhere in memory and fits in less than 8K.
Other features include device-independent
I/O and dynamic file allocation.
U.S. $34.95
International $52.45
XA6809 MACRO LINKING
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This new two-pass program generates relo-
catable and linkable code (requires LINK68).
Resident on any 6800 system, XA6809 lets
you produce code for a 6809 right now. This
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a COMMON section for the production of
ROMable code, conditional assembly and
fast execution.
U.S. $24.95
International $37.95
STRUBAL+™ includes a complete scientific
package, allows for string-handling and is
extensible. , _ . .. __
U.S. $49.95
International $74.95
TRACER: A 6800 DEBUGGING
PROGRAM
Ideal for the programmer looking for good
debugging software. TRACERfeatures single
step execution using dynamic break points,
register examination and modification, and
memory examination and modification.
Includes detailed TRACER program notes
and a reprint of "Jack and the Machine
Debug" (from the December 1977 issue of
BYTE magazine). U.S. $5.95
International $8.95
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copies ofTRACER DEBUGGING PROGRAM
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LINK68 LINKING LOADER
This is a one-pass linking loader which allows
separately translated relocatable object
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form a single executable load module, and to
relocate modules in memory. It produces a
load map and a load module in Motorola
MIKBUG loader format. This book provides
everything necessary for learning about this
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in general.
U.S. $7.95
International $11.95
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4
ArJsr
BYTE January 1981 211
Grunfeld-lndian Defense
18. g2xf3
19.0-0
Qe4-f5
White Black
Taunting Sargon 2.0 to do any harm...
Sargon 2.5 (level 4) Sargon 2.0 (level 3)
19
b7-b5
1 . d2-d4 Ng8-f6
2. c2-c4 g7-g6
20. Bc4-b3
21. Bc7-g3
Qf5-g5 ch
Qg5-f6
3. Nb1-o3 d7-d5
22. Rc3-c5
a7-a6
4. c4xd5 Nf6xd5
23. Bb3-d5
Ra8-d8
5. Nc3xd5 Qd8xd5
24. Qd1-c2
6. Ng1-f3 Bf8-g7
7. Bc1-f4
Threatening, of course,
25. Rc5-c8.
24
Qf6-f5
This gets the Bishop developed in preparation for 8. e2-e3.
25. Qc2xf5
g6xf5
Nb8-c6
26. Bd5-b7
e7-e6
8. e2-e3 Qd5-a5 ch
27. Bb7xa6
b5-b4
9. Qd1-d2 Nc6-b4!
28. Rc5-c4
Rd8-a8?
Not a bad move for a $30 program. But it will be fruitless.
Black was in serious trouble, but there was no reason to allow the
following clincher.
10. Ra1-c1 Bc8-f5
11,Rc1-c5 Qa5-b6
29. Bg3-d6 ch
Kf8-e8
12. Bf4xc7 Nb4-c2 ch
30. Ba6-b5 ch
Sargon 2.0 has been wanting to do this badly. Now, however, it is
The mating web starts.
•
in vain.
30
Ke8-d8
13. Rc5xc2 Qb6-e6
31. Rc4-c7
Ra8-a5
14. Bf1-b5ch Ke8-f8
32. Rc7-b7
15. Bb5-c4 Qe6-e4
Threat: Rb7-b8 mate.
16. Rc2-c3 Bf5-g4
17. Qd2-d1
32
33. Rb7-d7 ch
Ra5-a8
Kd8-e8
Sargon 2.5 is finding all the right defensive moves and is a pawn
34. Rd7-a7 ch
Ke8-d8
and Knight to the good.
35. Ra7xa8 mate
17 Bg4xf3
Table 2: Record of a complete chess game between Sargon 2.5 (running on the Chafitz Modular Game System) and Sargon 2.0
(running on an Apple II computer).
Technical Notes on Sargon 2.5 and the Chafitz
Modular Game System
The NIGS is a plastic case with a slide-out tray. The
top of the chessboard is brown and white soft grain
with algebraic-notation markings. In the tray is the
receptacle for the plug-in ROM, a keyboard (supplied
with a chess overlay), and a compartment with chess-
men — standard Staunton chess pieces, magnetized,
with a 2V*-inch King. There is an AC (alternating cur-
rent) adapter supplied. An optional battery pack is
available for $39. 95; on battery power, the unit can re-
tain an adjourned position for about 24 hours. The
total system price is $375.
Sargon 2.5 plays at six levels. Level 4 gives a reply in
2 to 4 minutes, plays in tournament time, and is rated
1641. If you want to wait 20 to 40 minutes per move at
level 5, the claimed rating is 1800.
took three games from Sargon 2.5. But when Sargon 2.0
won its first two games, apprehension mounted. We
wondered if there was a faulty ROM in Sargon 2.5, but
we decided it was unlikely. Later, Sargon 2.5 came back
to win two straight games against Sargon 2.0 and redeem
itself (see match results, table 3).
The circumstances of the first two losses to Sargon 2.0
are peculiar. In the first game, everything was even down
to pawns and King against pawns and King. But Sargon
2.0 gained a tempo (an advantage in time) and promoted
a pawn to Queen before Sargon 2.5 could. In the second
game, Sargon 2.5 played very speculatively on the attack
and lost a Bishop for a pawn, then later another pawn. A
whole Bishop down going into the end game with no
Opponent of
Sargon 2.5
Martellaro
J. Irwin
Sargon 2.0
USCF
Rating
(1700 + )
(1850)
(1600?)
Results
2 wins, 1 loss
1 win
2 wins, 2 losses, 1 draw
Table 3: An informal list of match results between Sargon
2.5 and other opponents.
compensation whatsoever caused me to declare a win for
Sargon 2.0.
This is hard to quantify or justify, but it appears that
Sargon 2.5 with its greater look-ahead capability plays
more (what I would call) speculatively. Sargon 2.5 will
play solid defense and sacrifice soundly, but it also ap-
pears to play a little more aggressively and loosely than
Sargon 2.0. Sargon 2.0 is very solid and conservative and
never risks too much. Because of this, Sargon 2.5 can get
into trouble on the offensive.
It is also peculiar that in the games Sargon 2.5 won, it
was on the defensive with White. (See the game score in
table 2.) Sargon 2.0 huffed and puffed on the attack with
Black for twenty moves, flailing away. When Sargon 2.5
was done fending off the attack, it was a Bishop and two
pawns up and proceeded to mate. Astonishing.
The difference in strength between Sargon 2.5 and
Sargon 2.0 seems small yet definite. My personal subjec-
tive experience is that Sargon 2.5 is more resilient on the
defense, and I would prefer to play Sargon 2.0 as the
weaker opponent. However, if you are running Sargon
2.0 on your microcomputer, the $300-plus investment for
the "improved" version is hardly worth it. Wait for
Sargon 3.B
212 January 1981 © BYTE Publications Inc
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BYTE January 1981 213
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SORT— Sort any number of fields, in any sequence,
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UPDATE— Single or dual file report and update utility.
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The MICROCONDUCTOIV" is power at your fingertips!
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Circle 134 on Inquiry card.
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Circle 135 for Microcomputer Tech
Circle 1 36 for Apparat
BYTE January 1981
Product Review
The SwTPC 6809 Microcomputer System
Tom Harmon, 1505 Magnolia Dr, Salisbury MD 21801
The SwTPC 6809 microcomputer system can be pur-
chased in kit form (as the 69/K) for $495 or assembled
and tested (the 69/A) for $595. Since I wanted to add
sockets for all the integrated circuits, I chose the kit. (The
assembled version doesn't use sockets.)
The 69/K and 69/A systems both include the MP-09
processor board, one MP-8M 8 K-byte programmable
memory board, the MP-S2 RS-232C serial-interface card,
and the MP-B3 motherboard with eight 50-pin slots and
eight 30-pin slots. The case and power supply are also in-
cluded.
The Processor Board
The MP-09 uses the Motorola 6809 microprocessor
with a 1 MHz clock. The 6809 is the third-generation ad-
Af a nianrp
Name
Hardware
69/K (kit) or 69/A
RS-232C terminal (for
(assembled) computer
input and output)
Use
Software
6809-based personal
SBUG-E monitor in ROM
computer
(included)
Manufacturer
Hardware Options
Southwest Technical
extra memory boards,
Products Corp, 219 W
expansion kit for serial
Rhapsody, San Antonio
interface, MF-69 5-inch
TX 78216 (512) 344-0241
floppy-disk system (in-
cludes FLEX operating
Dimensions
system)
length: 44 cm (17 inches)
width: 39 cm (15 inches)
Software Options
height: 18 cm (7 inches)
FLEX disk operating
system, other software
Price
products from TSC (see
$495 (for 69/K), $595
text) that are supported
(for 69/A)
by SwTPC
Features
Documentation
processor board contain-
looseleaf pages, 22 by 28
ing 6809 microprocessor
cm (8V2 by 11 inches), in
running at 1 MHz,
binder, with separate sec-
RS-232C serial-interface
tions on kit construction
card, 8 K bytes of pro-
(if applicable), sche-
grammable memory, fan
matics, parts layout,
operation
dition to the 8-bit 6800 family. It includes two 16-bit in-
dex registers, two 16-bit stack pointers, two 8-bit ac-
cumulators which can be treated as a single 16-bit register
for some operations, and a direct-page register for direct-
memory addressing. The 6809 includes all addressing
modes of the 6800 with the addition of program-counter
relative, extended indirect, indexed indirect, and
program-relative indirect. Assembly language written
with program-counter relative mode can be moved
anywhere in memory without reassembly.
The 6809 is not object-code compatible with the 6800.
Although 6800 source code can be reassembled with
minor changes, the code should be rewritten to take full
advantage of 6809 capabilities.
Sockets are provided on the board for three additional
2716 EPROMs (erasable programmable read-only
memory devices). However, the documentation says the
physical addresses of these may conflict with interface
addresses and recommends they be switched off.
Included on the processor board is an integrated circuit
that creates clock signals for various data-transfer rates.
Because of the shortage of pins on the SS-50C bus, some
of the clock signals share common bus lines and are
jumper-selected.
A DAT (dynamic address translator) allows physical
memory to be assigned as logical memory in any desired
order. Because of this, you don't have to strap memory
boards into consecutive memory locations. The principal
use for the DAT will be for multiuser/multitasking soft-
ware, which is still being developed.
A welcome feature is that the memory addresses used
for input and output have been moved to a higher loca-
tion to allow the 6809 to support 56 K bytes of program-
mable memory instead of the 32 K bytes supported on
older SwTPC 6800 systems.
The MP-09 processor board is silk-screen masked and
is of much higher quality than the memory board sup-
plied with the kit. The MP-09 board is intended for use
with the SS-50C bus and cannot be used with the older
SS-50 bus unless modifications are made to the mother-
board.
The SBUG-E Monitor
A 2 K-byte monitor (SBUG-E) is supplied in a ROM
(read-only memory) that is pin compatible with a 2716
EPROM. The monitor contains disk bootstrap routines
for both 5-inch and 8-inch floppy disks. A new DC-3
double-head single-density disk controller that is com-
216 January 1981 © BYTE Publications Inc
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OMEGA ships via UPS, truck, or air. COD's.
Visa, Mastercharge accepted, with no service charge.
Circle 137 on Inquiry card.
BYTE January 1981 217
Photo 1: The SwTPC 6809 microcomputer system. The factory-
assembled 69/ A sells for $595 and includes the three boards
shown here. Front to back are the MP-09 processor board, the
MP-8M memory board, and the MP-S2 RS-232C serial-interface
board. The kit version 69/K is $495.
Photo 2: The MP-8M programmable memory board for the
SwTPC 6809 microcomputer system. Both the kit and as-
sembled versions of the computer are shipped with one of these
8 K-byte boards. This board is addressable to any 8 K-byte
boundry within the first 32 K bytes of memory.
patible with the SS-50C bus is available from SwTPC for
$150. The older MF-68 disk controller cannot be used
with the SS-50C bus without modification. It has been
rumored that SwTPC may soon discontinue the MF-68
floppy-disk drive and replace it with a DT-5 unit, which
uses the Siemens double-head drive.
The SBUG-E monitor also includes a memory
diagnostic. It allows you to set and release breakpoints,
examine and alter memory, and examine and alter 6809
registers. Unfortunately, SwTPC does not provide source
listings of SBUG-E. However, a disassembled source
listing has been published in 68 Micro Journal (June
1980).
Serial Interface
The MP-S2 serial-interface card is supplied set up for
one serial port. It can be expanded to two ports by order-
ing the MP-SX expansion kit, which sells for $25. The
card must be installed in bus-row 0, driving the system
console with a standard RS-232C port. A nice feature is
that you don't need extra cables or connectors since the
DB-25 connector is mounted directly on the card.
Other Features
The MP-B3 motherboard uses the new SS-50C bus.
Since I/O cards have decoding performed for sixteen ad-
dresses, the new cards are not downwards compatible
with the SS-50 bus.
The power supply provides unregulated outputs of
±16 VDC and +8 VDC. Older SS-50 cards that
obtained 12 VDC from the bus will now require on-board
regulators.
The 6809 cabinet is constructed of heavy anodized
aluminum and is a major improvement on the older
SwTPC systems. I had no trouble getting the bolt holes to
align perfectly.
The quality of the parts supplied with the 69/K kit is
excellent. I did find several small components missing
from the kit but had no trouble getting replacement parts
from SwTPC.
AIM 65
AIM 65 is fully assembled, tested and warranted. With the addition of a low cost, readily available power
supply, it's ready to start working for you. It has an addressing capability up to 65K bytes, and comes
with a user-dedicated 1K or 4K RAM.
• Thermal Printer
• Full-Size Alphanumeric Keyboard
• True Alphanumeric Display
• Proven R6500 Microcomputer System Devices
• Built-in Expansion Capability
• TTY and Audio Cassette Interfaces
• ROM Resident Advanced Interactive Monitor
• Advanced Interactive Monitor Commands
PRICE: $389.00
Plus $4.00 UPS (shipped in U.S. must give street address), $10 parcel post to APO's, FPO's, Alaska,
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We manufacture a complete line of high quality expansion boards. Use reader service card to be added
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218 January 1981 © BYTE Publications Inc
Circle 138 on inquiry card.
DYNACOMP
Quality software for:
ATARI
PET
APPLE II Plus
TRS-80 (Level ID-
NORTH STAR
CP/M 8" Disk
GAMES
BRIDGE 2.0 (Available for all computers) Price: $17.95 Cassette
$21.95 Diskette
An all-inclusive version of [his most popular of card games. This program both BIDS and PLAYS
either contract or duplicate bridge. Depending on the contract, your computer opponents will either
play the offense OR defense. If you bid too high, the computer will double your contract! BRIDGE 2.0
provides challenging entertainment for advanced players and is an excellent learning tool for the bridge
HEARTS 1.5 (Available for all computers)
Price: $14.95 Cassette
$18.95 Diskette
An exciting and entertaining computer version of this popular card game. Hearts is a trick-oriented
game in which the purpose is not to take any hearts or the queen of spades. Play against two computer
opponents who are armed with hard-to-beat playing strategies.
CRIBBAGE 2.0 (TRS-80 only) Price: $14.95 Cassette
$18.95 Diskette
This is a well-designed and nicely executed two-handed version of the classic card game, cribbage. It is
an excellent program for the cribbage player in search of a worthy opponent as well as the beginner
wishing to learn the game, in particular the scoring and jargon. The standard cribbage score board is
continually shown at the top of the display (utilizing the TRS-80's graphics capabilities), with the cards
shown underneath. The computer automatically scores and also announces the points using the tradi-
tional phrases.
CHESS MASTER (North Star and TRS-80 only) Price: $19.95 Cassette
$23.95 Diskette
This complete and very powerful program provides five levels of play. It includes castling, en passant
captures and the promotion of pawns. Additionally, the board may be preset before the start of play,
permitting the examination of "book" plays. To maximize execution speed, the program is written in
assembly language (by SOFTWARE SPECIALISTS of California). Full graphics are employed in the
TRS-80 version, and two widths of alphanumeric display are provided to accommodate North Star
users.
STARTREK 3.2 (Available for all computers) Price: $ 9.95 Cassette
$13.95 Diskette
This is the classic Starirek simulation, but with several new features. For example, the Klingons now
shoot at the Enterprise without warning while also attacking starbases in other quadrants. The
Klingons also attack with both light and heavy cruisers and move when shot at! The situation is hectic
when the Enterprise is besieged by three heavy cruisers and a starbase S.O.S. is received! The Klingons
get even!
SPACE TILT (Apple only) Price: $10.95 Cassette
$14.95 Diskette
Use the game paddles to tilt the plane of the TV screen to "roll" a ball into a hole in the screen. Sound
simple? Not when (he hole gets smaller and smaller! A built-in timer allows you to measure your skill
against others in this habit-forming action game.
GAMES PACK I and GAMES PACK II Price: $ 9.95 each, Cassette
$13.95 each, Diskette
GAMES PACK I contains BLACKJACK, LUNAR LANDER, CRAPS, HORSERACE, SWITCH
and more. GAMES PACK II includes CRAZY EIGHTS, JOTTO. ACEY-DUCEY. LIFE. VVUMPUS
and others. Available for all computers.
Why pay S5.95 or more per program when you can buy a DYNACOMP collection for just $9.95?
STUD POKER (ATARI only) Price: $11.95 Cassette
$15.95 Diskette
This is the classic gambler's card game. The computer deals the cards one at a time and you (and the
computer) bet on what you see. The computer does not cheat and usually bets ihe odds. However, it
sometimes bluffs! Also included is a five card draw poker betting practice program. This package will
run on a 16K ATARI.
STATISTICS and ENGINEERING
DATA SMOOTHER (Not available for ATARI) Price: $14.95 Cassette
$18.95 Diskette
This special data smoothing program may be used to rapidly derive useful information from noisy
business and engineering data which are equally spaced. The software features choice in degree and
range of fit, as well as smoothed first and second derivative calculation. Also included is automatic
plotting of the input data and smoothed results.
FOURIER ANALYZER (Available for all computers) Price: $14.95 Cassette
$18.95 Diskette
Use this program to examine the frequency spectra of limited duration signals. The program features
automatic scaling and plotting of the input data and results. Practical applications include the analysis
of complicated patterns in such fields as electronics, communications and business.
TFA (Transfer Function Analyzer) Price: $19.95 Cassette
$23.95 Dbkette
This is a special software package which may be used to evaluate the transfer functions of systems such
as hi-fi amplifiers and filters by examining their response to pulsed inputs. TFA is a major modification
of FOURIER ANALYZER and contains an engineering-oriented decibel versus log-frequency plot as
well as data editing features. Whereas FOURIER ANALYZER is designed for educational and scien-
tific use, TFA is an engineering tool. Available for all computers.
FOURIER ANALYZER and TFA may be purchased together for a combined price of S29.95
(Cassettes) and $37.95 (Diskettes).
REGRESSION I (Available for all computers) Price: $19.95 Cassette
$23.95 Dbkette
REGRESSION I is a unique and exceptionally versatile one-dimensional least squares "polynomial"
curve fitting program. Features include very high accuracy; an automatic degree determination option;
an extensive internal library of fitting functions; data editing; automatic data and curve plotting; a
statistical analysis (e.g., standard deviation, correlation coefficient, etc.) and much more. In addition,
new fits may be tried without reentering the data. REGRESSION I is certainly the cornerstone program
in any data analysis software library.
REGRESSION II (PARAFIT) (Available for all computers) Price: $19.95 Cassette
$23.95 Diskette
PARAFIT is designed to handle those cases in which the parameters are imbedded (possibly nonlinear-
ly) in the fitting function. The user simply inserts the functional form, including the parameters (A(l),
A(2), etc.) as one or more BASIC statemeni lines. Data and results may be manipulated and plotted as
with REGRESSION I. Use REGRESSION I for polynomial fitting, and PARAFIT for those com-
plicited functions.
REGRESSION I and II may be purchased together for S36.95 (cassettes) and $44.95 (diskettes)
Availability
DYNACOMP software is supplied with complete documentation containing clear explanations and
examples. All programs will run within 16K program memory space (ATARI requires 24K). Except where
noted, programs are available on ATARI, PET, TRS-80 (Level II) and Apple (Applesoft) cassette and
diskette as well as North Star single density (double density compatible) diskette. Additionally, most pro-
grams can be obtained on standard 8" CP/M floppy disks for systems running under MBASIC.
BUSINESS and UTILITIES
MAIL LIST II (North Star only) Price: $21.95
This many-featured program now includes full alphabetic and zip code sorting as well as file merging.
Entries can be retrieved by user-defined code, client name or Zip Code. The printout format allows the
use of standard size address labels. Each diskette can store more than 1 100 entries (single density; over
2200 with double density systems)!
TEXT EDITOR I (Letter Writer) Pr ke: $14.95 Cassette
$18.95 Diskette
An easy to use, line-onented text editor which provides variable line widths and simple paragraph in-
dexing. This text editor is ideally suited for composing letters and is quite capable of handling much
larger jobs. Available for all computers.
PERSONAL FINANCE SYSTEM (ATARI only) Price: $34.95 Diskette
PFS is a single disk menu oriented system composed of 10 programs designed to organize and simplify
your personal finances. Features include a 300 transaction capacity; fast access; 26 optional user codes;
data retrieval by month, code or payee; optional printing of reports; checkbook balancing; bar graph
plotting and more. Also provided on the diskette is ATARI DOS 2.
FINDIT (North Star only) Price: $19.95
This is a three-in-onc program which maintains information accessible by keywords of three types: Per-
sonal (e.g., last name), Commercial (eg: plumbers) and Reference (eg: magazine articles, record
albums, etc). In addition to keyword searches, there are birthday, anniversary and appointment search-
es for the personal records and appointment searches for the commercial records. Reference records
arc accessed by a single keyword or by cross-referencing two or three keywords.
DFILE (North Star only) Price: $19.95
This handy program allows North Star users to maintain a specialized data base of all files and pro-
grams in the stack of disks which invariably accumulates. DFILE is easy to set up and use. It will
organize your disks to provide efficient locating of the desired file or program.
COMPARE (North Star only) Price: $12.95
COMPARE is a single disk utility software package which compares two BASIC programs and dis-
plays the file sizes of the programs in bytes, the lengths in terms of the number of statement lines, and
the line numbers at which various listed differences occur. COMPARE permits the user to examine ver-
sions of his software to verify which are the more current, and to clearly identify the changes made dur-
ing development.
COMPRESS (North Star only) Price: $12.95
COMPRESS is a single-disk utility program which removes all unnecessary spaces and (optionally)
REMark statements from North Star BASIC programs. The source file is processed one line at a time,
thus permitting very large programs to be compressed using only a small amount of computer memory.
File compressions of 20-50W are commonly achieved.
GRAFIX (TRS-80 only) Prke: $12.95 Cassette
$16.95 Diskette
This unique program allows you to easily create graphics directly from the keyboard. You "draw"
your figure using the program's extensive cursor controls. Once the figure is made, it is automatically
appended to your BASIC program as a string variable. Draw a "happy face", call it HS and then print
it from your program using PRINT HS! This is a very easy way to create and save graphics.
TIDY (TRS-80 only) Price: $10.95 Cassette
$14.95 Diskette
TIDY is an assembly language program which allows you to renumber the lines in your BASIC pro-
grams. TIDY also removes unnecessary spaces and REMark statements. The result is a compacted
BASIC program which uses much less memory space and executes significantly faster. Once loaded,
TIDY remains in memory; you may load any number of BASIC programs without having to reload
TIDY!
SIMULATIONS and EDUCATION
BLACK HOLE (Apple only) Price: $14.95 Cassette
$18.95 Diskette
This is an exciting graphical simulation of the problems involved in closely observing a black hole with
a space probe. The object is to enter and maintain, for a prescribed time, an orbit close to a small black
hole. This is to be achieved without coming so near the anomaly that the tidal stress destroys the probe.
Control of (he craft is realistically simulated using side jets for rotation and main thrusters for accelera-
tion. This program employs Hi-Res graphics and is educational as well as challenging.
V ALDEZ (Available for all computers) Price: $14.95 Cassette
$18.95 Diskette
A simulation of supertanker navigation in the Prince William Sound and Valdez Nanows. The pro-
gram uses an extensive 256X256 element radar map and employs physical models of ship response and
tidal patterns. Chan your own course through ship and iceberg traffic. Any standard terminal may be
used for display.
FLIGHT SIMULATOR (Available for all computers) Price: $17.95 Cassette
$21.95 Diskette
A realistic and extensive mathematical simulation of take-off, flight and landing. The program utilizes
aerodynamic equations and the characteristics of a real airfoil. You can practice instrument approaches
and navigation using radials and compass headings. The more advanced flyer can also perform loops,
half-rolls and similar aerobatic maneuvers.
TEACHER'S PET I (Available for all computers) Price: $ 9.95 Cassette
$13.95 Diskette
This is the first of DYNACOMP's educational packages. Primarily intended for pre-school to grade 3,
TEACHER'S PET provides the young student with counting practice, letter-word recognition and
three levels of math skill exercises.
Ordering Information
All orders are processed and shipped postpaid within 48 hours. Please enclose payment with order along
with computer information. If paying by VISA or Master Card, include all numbers on card. For orders
outside North America add 10ft for shipping and handling.
Add S2.50 to diskette price for 8" floppy disk (soft sectored, CP/M, Microsoft BASIC)
'TRS-80 diskettes are not supplied with DOS or BASIC.
Deduct 10% when ordering 3 or more programs.
Ask for DYNACOMP programs at your local software dealer. Write for detailed descriptions of these and
other programs from DYNACOMP.
DYNACOMP, Inc.
6 Rippingale Road
Pittsford, New York 14534
(716) 586-7579
New York Suit residents pleue add 7tt NVS sales las.
Circle 139 on inquiry card.
BYTE January 1981 219
31^^S 1^\ The improved
3l\^J l\/« version of BKG9.8,
the BACKGAMMON playing program that
defeated the '79'-'80 World Backgammon
Champion by a score of 7-1!
f'%,^ BKQl6.,developed°with the
help of Paul Magriel former
? world champion and author
of BACKGAMMON, has
emerged as one of the
best examples of artificial
| intelligence software
available for micro-
computers.
Vers I $79.
^ Vers II $129.
FEATURES:
* Version I: Full direct cursor screen control for professional
display of beard, dice, etc.
* Version II adds printer/ disk output of game in progress,
board initialization at non standard positions, and simulation
capabilities.
* BKG 10. utilizes advanced SNAC functions (smooth,
nonlinear application coefficients) as described in Scientific
American, June, 1 980.
* Complete game rules including: doubling, match play and
Crawford Rule. Will play man-machine, either side or
.i machine-machine with Version II.
' BKG 10. makes most moves in under 20 seconds (2MHZ)
or 10 seconds (4 MHZ).
* BKG 10. was written entirely in Z-80 assembler.
ANNOUNCING:
G OMO K U
Compete against
your machine to
arrange five stones in a
row on a 19 by 19 matrix. ! !
Play this game for fun but be prepared for defeat as
it exploits your human weaknesses in this entirely
logical game. You may allow yourself a handicap, ask
for the prefrred move, store a game position, recall a
game from disk, output a game to the printer or re-
play a game from memory for study.
• SYSTEM REQUIREMENTS •
Z-80 Processor, 40k CP/M for BKG 10 Vers I, 48k for BKG 10 Vers II
and GOMOKU, cursor addressable video terminal (specify terminal
model, most makes supported), 8" or 5^4" floppy drive. Formats
available for TRS-80 Model II, Northstar, Cromemco, others.
For MasterCard and CODs only-
CALL NOW (800) 824 -7888
in California: 800-852-7777
in Alaska/ Hawaii: 800-824-7919
please ask for Operator 105
Intelligence Systems Ltd.. Indianapolis. IN - (317) 631-5514
The documentation supplied with the 69/K system is
adequate, but the construction manuals are not as de-
tailed as those of some other manufacturers. For exam-
ple, you are told to install all resistors as a single step in
construction, and you are expected to know the resistor
color codes and be able to identify the polarity of all
polarized capacitors. I would not recommend this kit for
a beginning kit builder. However, an experienced builder
should have no trouble.
Construction Hints
I selected low-profile tin soldier-tail sockets manufac-
tured by Texas Instruments for use on the printed-circuit
boards. These sockets may be purchased from a number
of sources, including Digi-Key Corporation, POB 677,
Highway 32 S, Thief River Falls MN 56701.
The straight pin-edge connectors on the motherboard
seem to slope in one direction and the 10-pin male con-
nectors should be installed with the slope in the same
direction. This avoids problems when the printed-circuit
boards are inserted later. You might also find it easier to
remove the socket index pin before soldering the sockets
to the board.
The Added Extras
In order to communicate with your microcomputer
system, you'll need an RS-232C-compatible terminal. I
selected the Heath H-19 video terminal over the SwTPC
CT-82 because I prefer the larger 12-inch display size of
the Heath. (The SwTPC CT-82 has a 9-inch display.) The
normal format of the Heath H-19 is 24 lines by 80
characters, while the CT-82 format is 16 lines by 82
characters.
You'll probably want additional memory because only
4 K bytes of the supplied 8 K bytes of programmable
memory are available for use. The SBUG-E monitor
assigns a 4 K-byte area for a system stack and for internal
tables and addresses. SwTPC sells additional MP-8Mb
bare boards with edge connectors for $17. By buying
your own integrated circuits and memory from indepen-
dent suppliers, you can save a considerable amount of
money over assembled units.
Digital Research Computers (POB 401565, Garland TX
75040) sells a 16 K-byte programmable memory board
for the SS-50 bus ($26). The board uses type-2114 in-
tegrated circuits instead of the type-4044 programmable
memory devices used by the MP-8M board. The quality
is excellent and well worth adding to your 6809 system.
Of course you'll also need either a cassette-tape unit
(like the SwTPC AC-30) or a floppy-disk system for
loading and saving programs.
Software
The FLEX 09 version 2.6 disk operating system is
available from SwTPC. The price ($35) includes a
manual and object-code disk. FLEX 09 can be used with
most of the 6809 software available from TSC (Technical
Systems Consultants, POB 2574, West Lafayette IN
47906). TSC has a large amount of 6809 software, in-
cluding a text editor, an assembler, several versions of
BASIC, a debugging package, and others.
CSI (Control Systems Inc, 1317 Central, Kansas City
KS 66102) has the UCSD Pascal compiler for $419 that
Circle 140 on inquiry card.
PET and the
IEEE 488 Bus
(GPIB)
by E. Fisher and
C. W Jensen
This is the only complete guide available on
interfacing PET to GPIB. Learn how to program
the PET interface to control power supplies,
signal sources, signal analyzers and other
instruments. It's full of practical information, as
one of its authors assisted in the original design
of the PET GPIB interface.
#31-4 $15.99
NEWPET/CBM
edition
Some Common
BASIC Programs
by L. Poole, M Borchers,
C. Donehue
76 Programs you cen use even if you don't
know BASIC. This book gives you e variety of
math power including personal finance, taxes
and statistics as well as other programs you'll
want like Recipe Cost and Check Writer. All
programs can be run on a PET or CBM with 8K
or more.
#40-3 $14.99
PET owners can purchase the programs ready-
to-run on cassette or disk. Use the book as a
manual for operating instructions and
programming options.
Disk #33-0 $22.50
Cassette #25-X $15.00
Practical BASIC Programs
ed. Lon Poole
These are 40 easy to use programs that
each do something useful.
Income averaging, checkbook reconciliation,
statistics, factorials, temperature conversion
and musical transposition are just a few. It offers
a wealth of practical computing power. Includes
write-ups, program notes and instructional
examples to help you realize the potential uses
of each program.
#38-1 $15.99
6602
Assembly Language
Programming
by L. Leventhal
Increase the capabilities and performance of
PET (end other 8502-based computers) by
learning to program in assembly language.
#27-6 $16.99
New for your PET
from
{j\ OSBORNE/McGraw-Hill
PET™/CBM™ Personal Computer Guide
Second Edition
by Adam Osborne and Carroll S. Donahue
The PET/CBM Personal Computer Guide is a step-by-step guide that assumes no
prior knowledge of computers. If you can read English, you can use this book.
This book provides the important information and documentation that PET/CBM
users have sought for so long. After reading this book you will have
a good understanding of what a computer —
especially the PET/CBM
computer — can do for you. If you've just / j^
bought a PET or CBM this is the book you
must have to really understand your
computer. By using the examples
found in this book, you will quickly
get your PET/CBM up and running. These
examples are thoroughly documented so
you can learn how and why the programs
work. It is the "how" and the "why" that
are important if you want to learn how to
make your PET or CBM work efficiently
for you.
This second edition contains even more
useful information than the first
edition of this book.
The guide contains a wealth of
information on everything
from keyboard variations
to a detailed description
of PET and CBM memory.
Included are:
Complete operating instructions for
■ keyboard
■ tape cassette
• disk
Description of all CBM BASIC statements
Optimal programming techniques including
■ input/output programming
* file handling
■ screen editing
Solutions to programming problems
CBM capabilities and limitations
#55-1 $15.00
Book/Caeeette/Dlek
Prloe
Quantity
Amount
27-6 6602 Assembly Language Programming
$18.99
30-fl PET Personal Computer Guida
$16 00
3 1 -4 PET and the IEEE 488 Bui IGPIQI
$1599
40-3 Some Common BASIC Programa PET/CBM ad. (book)
$1499
26-X Soma Common BASIC Programt PET Caaaatte
$15.00
33-0 Soma Common BASIC Programt PET Diak
$22.60
38-1 Practical BASIC Program!
Si & 99
California raiident tax
Shipping
■ I Amount Enclaead
Shipping: (Shipping for large orders to ba arranged)
• All foreign ordari $4.00 par book for airmail
^-^630
OSBORNE/McGraw-Hill
630 Bancroft Way, Dept.BII
Berkeley, California 04710
(416) 648-2806 • TWX 910-366-7277
706
Name:,
Address:,
City:
• $0.45 par book 4th clan in tha U.S. (allow 3-4 wmVi)
• SO 75 par book UPS in tha U.S. (allow 1 days)
• $1.60 par book apacial ruih ahipmant by air in tha U.S.
Caaialtai and Diak:
a No additional charge in tha U.S
• $1 .60 aach foreign airmail
State :_
Phone:.
Dvisa
Credit Card No.:
□ Master Card
Circle 141 on Inquiry card.
BYTE January 1981 221
YOU'RE RIGHT!
KEYED FILE ACCESSING
is essential to develop effective application
programs under CP/M® for your 8080/Z80 machine.
Your on-line, interactive systems demand the
performance that only a professional keyed file
accessing package can offer: fast random and
sequential access to data by key values, on-line
additions and deletions to your data files,
elimination of lengthy sorting procedures.
BUT WHICH ONE?
Feature
MICRO B- w The Other One
• Random Access by Key
YES
YES
• Wild Card Search
YES
YES
• Key-Sequential Access
YES
YES
• Multiple Keys
YES
YES
• Automatic Space
Reclamation
YES
YES
• Eliminate Overflow Files
YES
NO
• Maximum Number of Entries
65,535'
10,000
• Eliminate Index File
Reorganization
YES
NO
• Guaranteed Optimal Index
File Structure
YES
NO
• Maximum Disk Accesses To
Reach Any of 10.000 Entries
3
?
• Duplicate Key Values
YES 2
NO
'32.767 for the source code versions
2 Source code versions only.
IT'S OBVIOUS, GET MICRO B+™!
And search an index of over
1 0,000 key values in less than one
second on a floppy disk system!
Assembly Language Version ...$260.00
Specify MICROSOFT. CBASIC", PL/l-80'". S-BASIC"
Basic Source Code Version ...$195.00
Specify MICROSOFT Basic or CBASIC"
Shipping $2 USA / $5 Foreign
We accept VISA and MASTERCARD
DEALER INQUIRIES INVITED
RIrCom
Making Micro's work like Maxl't
© 1980 Fair Com
2606 Johnson Drive
Columbia, MO 65201
(314) 445-3304
CP/M and PL/l-80 are trademarks of Digital Research
MICROSOFT is a trademark of MICROSOFT. Inc.
CBASIC Is a trademark of Compiler Systems. Inc.
S-BASIC is a trademark of Topaz Programming
will run on a 6809 system with 56 K bytes of program-
mable memory. The software is available on both 5-inch
and 8-inch floppy disks, and includes operating system,
compiler and linker.
System Checkout
The power-supply cables and voltages are first checked
without any other boards installed. Then the mother-
board is installed, and finally the remaining printed-
circuit boards. You will need an RS-232C-compatible ter-
minal connected to the serial-interface card to test for the
proper message, "S-BUG 1.5-8 K", followed a blinking
cursor.
When I performed the checkout, everything appeared
to be normal until I attached a terminal and noticed that
the video display consisted of question marks being pro-
duced much faster than the current data-transfer rate,
which was 300 bps (bits per second). The SwTPC
documentation states that if anything is printed, especial-
ly question marks, the computer is probably working and
that the problem is probably with the terminal parity, bit
format, or data-transfer-rate setting.
I spent a considerable amount of time checking for
problems and couldn't find anything wrong until I used
my ohmmeter and observed that the resistance between
the 300 and 4800 bps lines on the motherboard measured
about 2 ohms. I immediately suspected a solder bridge
but was unable to find one I then called in a friend with a
very accurate ohmmeter. He detected a dip in the
resistance at the closest pin on the motherboard. Using a
projector lens, he found two extremely small copper
bridges that were covered by the green coating on the
motherboard and were virtually impossible to see with
the naked eye. After I removed the copper bridges with a
small knife, the system worked beautifully.
The moral of this story is that you should be careful to
check adjacent bus lines on the motherboard both initial-
ly and after assembly. Doing this will eliminate a lot of
frustration and wasted time.
Conclusions
I'm pleased with the overall quality of the SwTPC
69/K, and I recommend it to any experienced kit builder.
One big headache-saver is to check out individual fin-
ished boards on a working SS-50 or SS-50C system. I
used a friend's SS-50 computer to test the 8 K-byte pro-
grammable memory board supplied with the kit.
If you don't have a means of testing individual boards,
I strongly suggest the purchase of the 69/A assembled
and tested system. When you consider the amount of
time spent assembling and testing the unit, the extra $100
seems like a bargain.
SwTPC does have technical services available, but the
entire computer must be repacked and sent to San An-
tonio, Texas. Without the proper test equipment, it is dif-
ficult, if not impossible, to track down specific problems.
If you purchase factory-assembled boards, SwTPC
does offer a factory exchange program. Boards can be ex-
changed for a fixed fee ($40 for the MP-09 processor
board). All factory-assembled products are included in
the plan for 6 months, and SwTPC will arrange a service
contract after the 6-month period. If you're using your
computer for business, this service is ideal. ■
222 January 1981 © BYTE Publications Inc
Circle 142 on inquiry card.
CALL FOR PAPERS
W EUROMICROSl
SEVENTH SYMPOSIUM ON MICROCOMPUTING
PARIS, SEPT. 7-10, 1981
THE SYMPOSIUM
EUROMICRO 1981 is the seventh annual symposium
organized by EUROMICRO, the European Associa-
tion for Microprocessing and Microprogramming.
Previous annual conferences have been held in Nice,
Venice, Amsterdam, Munich, Goteborg and London.
The purpose of this conference is to bring together
practitioners and theoreticians from industry, govern-
ment and academia who are interested in all prob-
lems relating to the underlying concepts and the use
of microprocessing and microprogramming.
SUBMISSION OF PAPERS
Authors are invited to submit original papers on
recent and novel work in the whole field of
microprocessing and microprogramming. Solicited
are all contributions concerning problems of hard-
ware, firmware, software and applications that are
typical with respect to systems, development, social
implications and education.
Authors should submit six complete copies of their
papers to the program chairman not later than by
March 15, 1981.
EUROMOUSE IN PARIS— CALL FOR MICE
EUROMOUSE™ is the European version of IEEE Micromouse contest where a microcomputerized "mouse" must
find its way in a labyrinth.
FOR FULL DETAILS:
EUROMICRO, 18 rue Planchat, 75020, Paris, France Tel: 1/370-3275 Telex: 211801
Or Contact: Dr. Rodnay Zaks, SYBEX, 2344 Sixth Street, Berkeley, CA 94710 Tel: 415/848-8233 Telex: 336311
Circle 143 on inquiry card.
BYTE January 1981 223
As your introduction to The Library Of
Computer and Information Sciences
Take this
$60.00 classic
for only $3.00
ENCYCLOPEDIA OF COMPUTER SCIENCE
Edited by Anthony Ralston and Chester L. Meek. More lhan 1550 oulsize
pages of information on every aspecl of computer science— from algebra to
automata theory, from basic terminology to string-processing languages. 470
articles by 208 experts. Over 700 charts, tables, graphs and diagrams.
or 3 other
books for only $1 each
(values to $74.90) SRWKSEKSB
(Publishers' Prices shown)
and
only 3 more books-at handsome
discounts-over the next 12 months.
discipline
programming
fdsge
mwivMssm
ser
jksti
dijkstra
42303. A DISCIPLINE OK 62641. MICROPROCES-
PROGRAMMING. Edsger
W. Dijkstra. Program deriva-
tion and composition, com-
mon mistakes; plus numerous
other examples. $21.95
SORS: From Chips to Sys-
tems. Rodney Zaks. Detailed
examples, photographs, dia-
grams and appendices. 525.00
I intemtiw
//jflwji/Bte/s
87970-2. WRITING IN-
TERACTIVE COMPILERS
AND INTERPRETERS. P. J.
Brown. Includes how to de-
sign an internal language,
error detection and diagnosis
in the run-lime svstem. and
much more. Counts us 2 of
your .$ hooks. $26.95
224 BYTE January 1981
79155. SOFTWARE INTER-
PRETERS FOR MICRO-
COMPUTERS. Thomas C.
Mchuire. How to design a
reliable software interpreter
for anv microcomputer sys-
tem. ' $23i95
56395. AN INTRODUCTION
TO PROGRAMMING AND
PROBLEM SOLVING
WITH PASCAL. G. Michael
Schneider el al. Presents the
fundamentals of PASCAL, a
new computer language.
$15.50
54455. IMS PROGRAM-
MING TECHNIQUES: A
Guide to Using DL/1. Kapp
and Lehen. Spells out specific
techniques to write applica-
tion pros rams in ANS.
COBOL. PL/I. or Assembler
Language in an IMS DL/I
data base environment.
$17.95
38319-2. CLASSICS IN
SOFTWARE ENGINEER-
ING. Edited by Edward Nash
Yourdon. A compendium of
reference articles. 424 pages.
Softcover. Counts as 2 of your
i hooks. $28.00
■UCMWM
predicts
una***
51955-2. A GUIDE TO THE
SUCCESSFUL MANAGE-
MENT OF COMPUTER
PROJECTS. Hamtih Don-
aldson. Counts as 2 of your 3
books. $34.95
SOFTWARE
GUIDEBOOK
BvB »w" "-
79167. SOFTWARE RELI-
ABILITY GUIDEBOOK.
Robert I.. Glass. Spells out all
the technological and man-
agement techniques. SI8.95
42053-2. DESIGNING A
DISTRIBUTED PROCESS-
ING SYSTEM. Hamlsh Don-
aldson, Includes file strategy,
communication networks and
workflow design. Counts as 2
of lour i hooks. S34.95
"TbeCCBCL
38968. THE COBOL ENVI-
RONMENT. Graucr and
Crawford. $20.95
70745. A PROGRAMMER'S
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If the reply card has been removed, please write to
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to obtain membership information and an application.
BYTE January 1981 225
The Picture-Perfect Apple
Phil Roybal
1111 Pippin Creek Ct
San Jose CA 95120
A picture is worth a thousand
words. And it was the capability of
representing information in pictures
that initially attracted me to the
Apple II computer.
But images on a screen can be too
personal an experience. Often no one
else sees them. It would be great if
there were a way to transcribe these
images so that others could also ap-
preciate them. There is a way to do it,
and this article tells how.
The program discussed here was
written in Apple (6502) assembly
language for the Qume Sprint Micro
3, a daisy-wheel printer with a 16-bit
parallel interface. The approach is
quite general in nature; therefore,
you will find it easy to adapt it to
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SEE OUR AD FOR 8" FLOPPY NORTH STAR SUBSYSTEM ON PAGE 144
JOHN D. OWENS
Associates, Inc.
12 Schubert Street
Staten Island, New York 10305
212 448-6283 212 448-2913 212 448-6298
other hardware.
The high-resolution screen of the
Apple II is actually a window into the
memory between decimal addresses
8192 and 16,383. Anything you see
there can be printed on paper. This
means that if you have a graphics
printer, you needn't go to a lot of
trouble writing plotting routines for
it. Those already available in the
Apple languages and utility programs
will suffice quite handily.
This capability can be put to good
use the next time you need to produce
a high-quality chart for a presenta-
tion, or an attention-getting cover for
a report. You can do the job on the
same letter-quality printer you used
to produce the report itself.
Even if you don't have one of these
elegant but expensive printers, this
routine is still useful. Very little
depends upon either the printer or the
interface. In fact, the bulk of the
routine is concerned with decoding
the high-resolution screen addresses.
Therefore, you can quickly tailor the
printer routine to your hardware.
The High-Resolution Graphics
Screen
The Apple graphics screen is a
tricky beast. If you calculate how
much memory it should consume, it
comes out:
280 dots X 192 lines = 53,760 pixels
Then consider that there are eight
colors that can be displayed. This
means you throw in 3 bits per pixel to
wind up with:
53,760 X 3 = 20,160 bytes
of memory
Despite this, the screen takes up only
8192 bytes. How is this done?
The screen doesn't show every
color in every location. Only black-
and-white images take advantage of
the full resolution of the screen.
Colors show up in alternate columns
(green alternates with violet, orange
with blue, etc). Apple's video cir-
cuitry and the television set's
response characteristics combine to
make the rows of colored dots appear
to fuse together. Thus, you can draw
a "solid" horizontal line across the
screen, regardless of the color you
plot it in.
226 January 1981 © BYTE Publications Inc
While this bit of trickery does save
memory, it makes analyzing screen
images rather complex since you have
to figure out what the color is at any
given location. Fortunately, since
most printers produce only black and
white, the color issue is academic. If a
dot is there, the printer prints it. The
end result is that colors appear as less
dense clusters of dots than solid
white, providing a shading effect to
images produced on the printer.
What causes the most difficulty is
that the designer of the Apple saved
himself a logic gate or two through
the use of rather unorthodox screen
addressing. As a result, adjacent
screen rows do not occupy con-
secutive memory locations. It is the
decoding of this high-resolution
screen addressing which accounts for
a good deal of the complexity of this
program. The software has to use a
series of counters to keep track of
where it is on the screen. (Figure 2
shows how it works.)
The high-resolution
screen of the Apple II Is
actually a window into
the memory.
High-resolution screen addressing
is easy to understand if it is con-
sidered as a series of hexadecimal
rather than decimal numbers.
As shown in figure 1, the screen is
divided into three major sets of
horizontal lines which I call triads.
Each triad is divided into eight groups
of horizontal lines called octets. And
finally, each octet consists of eight
horizontal lines called fillers. A line
consists of 280 dots, which are de-
rived from 40 bytes of memory by us-
ing the lower 7 bits of each byte. This
is how it works.
The triads begin with lines whose
first bytes (leftmost characters) have
hexadecimal addresses:
2000
2028
2050
If you poke Is into these addresses
while the high-resolution screen is
black, dots will appear along the left
margin, evenly dividing the screen
vertically into thirds.
Within a triad are octets. The
octets begin with lines whose first
bytes are incremented by hexa-
decimal 80 from the starting address
of the triad. For example, the first
triad, which starts at hexadecimal
2000, has octets beginning with lines
whose first bytes have hexadecimal
addresses:
2000
2080
2100
2180
2200
2280
2300
2380
Each ocfef has eight lines within it.
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JOHN D. OWENS
Associates, Inc.
SEE OUR AD ON FACING PAGE
January 1981 © BYTE Publications Inc 227
Circle 144 on inquiry card.
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These lines start with bytes whose ad-
dresses go up in increments of hexa-
decimal 400 from the octet starting
address. Thus, the first octet of the
first triad has eight lines in it that start
with the hexadecimal addresses:
2000
2400
2800
2C00
3000
3400
3800
3C00
This is a bit complex. It helps if you
work out a table and verify it by pok-
/* 2000
ing information into the high-resolu-
tion screen area. Adapting the pro-
gram to handle a different printer is
relatively trivial compared to under-
standing the address scheme. Thus,
this algorithm is a good base to build
on, no matter what hardware you
use.
A Tour of the Driver
The driver routine (see figure 2)
knows that the screen is contained in
the memory area between hexa-
decimal 2000 and 3FFF. Therefore, it
moves the print head to the left
margin and then starts with hexa-
decimal address 2000, in the first
First
Triad
2000
First
Octet
2080
Line
Beginning
Locations
^ 2028
r
Second
Octet
Third
Thru
Eighth
Octets
2028
2000
2400
2800
2C00
3000
3400
3800
3C00
2080
2480
2880
2C80
3080
3480
3880
3C80
2100
2028
Second
Triad
First
Octet
Second
Thru
Seventh
Octets
Eighth
Octet
^- 2050
r
2050
Third
Triad
V.
First
Octet
Second
Thru
Seventh
Octets
Eighth
Octet
Figure 1: Apple II high-resolution screen-memory addressing. All addresses shown are
in hexadecimal radix. The screen is divided into three major sets of horizontal lines
called triads. Each triad is divided into eight groups of horizontal lines called octets.
Each octet is divided into eight horizontal lines called fillers. Each line uses 40 bytes of
programmable memory and consists of 280 dots.
228 January 1981 © BYTE Publications Inc
Can your
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Requires CP/M (a trademark of Digital Research) or compatible operating systems, eg. CDOS, ADOS, etc.
Circle 145 on inquiry card.
ITIkroPfO
INTERNATIONAL CORPORATION
The Star Maker
MicroPro International Corporation
1299 4th Street, San Rafael, CA 94901
(415) 457-8990 TELEX 340388
Sold through authorized dealers and
distributors only. OEM inquiries invited.
BYTE January 1981 229
Circle 146 on inquiry card.
CALL OUR TOLL FREE NUMBER
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Bay Area Residents add 6'-':% sales tax.
Calif. Residents add 6% sales tax.
JDR MICRODEVICES, INC.
1101 South Winchester Blvd.
San Jose, California 95128
800-538-5000
408-247-4852
230 January 1981 © BYTE Publications Inc
triad, first octet, and first filler line, has found a dot.
Beginning at one end of the first line, In the first case, the complete line is
it looks at the lower 7 bits of each blank (all zeroes), so the driver issues
byte until it has scanned (decimal) 40 a line feed. It then picks the next line
bytes without finding a dot, or until it (in this case, the second filler line in
f ENTRY J
INITIALIZE PRINT HEAD POSITION
TR=OC=FL=BYT=MSK=0
ADDR =
$2000+ ($28*TR)+ ($80*0C) + ($400*FL)+ BYT
DATA=SCREEN (ADDR)
DATA = DATA AND MASK (MSK)
YES
DELTA = ABS(HEAD POS'N- DOT POS N)
CONSTRUCT HEAD MOTION STRING
MOVE HEAD 1/60" PER DOT
UPDATE HEAD POS'N COUNTER
RAISE RIBBON AND PRINT DOT
BYT =
LINE FEED 1/48"
FL = FL+1
0C=0C+1
MSK=MSK+1
MSK =
RESET PRINT HEAD
TO LEFT EDGE
f RETURN )
Figure 2: Flowchart for a program to drive the Qume Sprint Micro 3 plotter to print
Apple II screen graphics. The shaded boxes indicate hardware-dependent code,
although the code is very similar for all 16-bit parallel printers. Abbreviations are as
follows: TR = triad counter; OC = octet counter; FL=filler counter; BYT = filler-line-
byte counter; and MSK=seven-dot byte mask.
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AARDVARK SOFTWARE INC.
The Microcomputer Peoplefor Professionals
783 NORTH WATER STREET MILWAUKEE. WISCONSIN 53202 414/289-9988
Circle 147 on inquiry card.
BYTE January 1981 231
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Model 30 $4495 $3955
Model 40 $4995 $4395
HARD DISKS
Intertec's Winchester type 8" hard disk
for Superbrain or Compustar Terminal
1 Omb Sugg. List $4995 YourCost$3890
Call for prices on 32 mb and 96 mb hard disks,
TERMINALS
Intertube III .Sugg. List $ 895 .... Your Cost $750
Emulator. . .Sugg. ListS 895. .. . Your Cost $750
WORD PROCESSING
VTS80
Reg. $549 $469
Magic Wand
$400 $325
COMMUNICATIONS
Link 80
Reg. $100 . .Your Cost $89
— — SOFTWARE — ^—
CBasic MBasic Reg. Your Cost
Accounts Receivable X X $ 750 $350
Accounts Payable X X 750 $350
General Ledger X X 750 $350
Payroll X X 750 $350
Inventory X X 750 $350
Restaurant Payroll X 750 $350
Job Costing X 750 $350
Mailing List X $150
Mailing List (NAD) .$150
Master Tax Package (CP Aids) $1500 . . .$995
Restaurant Cost & Inventory Program . . $750 . . . $350
Graham-Dorian
Medical Billing $1000 . . .$899
Dental Billing $1000 . . . $899
Cash Register Inventory Program $750 . . . $500
Printers
DOT MATRIX
$
595
MPI 88T Sugg. List $749
MPI 88G ...Reg. $749 Your Cost $650
With graphics option ..$799 $700
Paper Tiger
Model 440 $995 $895
Model 440 w/graphics
&2KBuffer $1100 $985
TI810 $1895 $1650
Tl 81 w/full ASC II $2155 $1 950
Artadex
DP 9500 $1650 $1399
DP 9501 $1650 $1399
Daisy Wheel
Diablo $2950 $2180
ROw/tractor . ..$3250 $2380
NEC 5510 $2950 Call for price
Xymec Typewriter
Printer $2650 $2350
Vista V 300 ..$1395 $1795
Qume Sprint
5/45 RO $3073 $2695
KSR $3537 $3145
w/tractor $3787 $3350
Other Hardware
CAT Novation Modem .$199 $169
Cash Register Interface .$1000 $795
EProm $125 $120
Upgrade kit cuts in half access time.
Allows serial number of machine on chip
and all software.
DISKETTES — —
Verbatim
Double density,
Single Sided,
Pkg.of 10 $60.
Double density,
Double Sided,
Pkg.of 10 $75.
LANGUAGES
CBasic YourCost$125
M Basic $325
Fortran $450
Cobol $650
DEALER INQUIRIES INVITED
TO ORDER CALL
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the first octet) and again scans it from
end to end. This pattern continues (if
the whole screen is blank) through the
eight filler lines of each octet, the
eight octets of each triad, and all
three triads, until the end of the
screen is reached. Then the driver
jumps back to the routine that called
it.
When a nonzero bit (a dot on the
screen) is found, the driver calculates
the distance from the present print
head location (normally over the last
dot printed) to the new dot position.
It then moves the print head into
place in a single step (instead of ratch-
eting along over every dot position).
When the print head is in place, the
dot is printed.
In the driver written here, if at least
one dot has been printed on a line, the
next line will be scanned and printed
from the opposite direction. This pro-
vides the fastest printing with
minimum wear and noise under
average conditions. While this
scheme is not 100% optimized, it
does yield very acceptable perfor-
mance. The determination of scan-
and head-motion direction adds com-
plexity to the algorithm without con-
tributing to the basic capability, so
this feature is omitted from the flow-
chart in the interests of clarity.
The bulk of this program is
dedicated to screen-address decoding.
The only section tightly woven about
the hardware is the output routines.
These come last in the source code to
facilitate changing them without
reassembling the entire driver. They
assume that you are using a Qume
printer receiving 16-bit parallel code
in the format shown in figure 3. If
you are using another printer and in-
terface, just write code to send the
correct control characters to your
printer hardware.
Using the Plotter
The driver was written for a printer
that provides horizontal resolution of
120 steps per inch and vertical resolu-
tion of 48 steps per inch. Two
horizontal increments are used for
each screen dot, and one vertical in-
crement is used for each line. As a
result, the printer will reproduce the
high-resolution graphics screen in a
space about 11.3 by 9.8 cm (4.7 by 4
inches). This area will be centered on
a 20.8 cm- (8V2-inch) wide page, and
will start printing at wherever the
paper is located at the time the driver
is called.
Once you have loaded the driver
and produced an image in high-
232 January 1981 © BYTE Publications Inc
Circle 148 on inquiry card.
DEC® LSI® 11/23 COMPUTERS $6750
and we're delivering from stock!
CI-103 DESK TOP COMPUTER. Available with LSI 11/23 or LSI 1 1/2. Complete computer system
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Memory. $6750 with LSI 11/23 and 96K Bytes Memory.
PDP 1103SE — LSI 11/2 CPU, 64KB Memory, power
supply, KEV 11 in 8 slot rack mountable chassis. $2695
CI 1103LK — LSI 11/2 CPU, 64KB Memory, power supply,
KEV 11 in 16 slot rack mountable chassis. $2750
CI-11/23 AC — LSI 11/23 CPU, MMU, 256KB Memory,
power supply, in 16 slot rack mountable chassis. $6895
LSI 11/2 CPU card with 64K Byte
Memory. $1095
1 Megabyte RX02 Floppy Disk
System. $3045
RT11 V4 Operating System. $1085
RSX11M Operating System. $3250
VT100AA Video Terminal. $1795
c
Chrislin Industries, Inc.
Computer Products Division
31352 Via Colinas • Westlake Village, CA 91362 • 213-991-2254
DEC. LSI. PDP. are Trademarks of Digital Equipment Corp
Circle 149 on inquiry card.
BYTE January 1981 233
Circle 150 on inquiry card.
Edmund
Scientific
Catalog
I Edmund Scientific Catalog
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resolution page 1, just turn on your
printer and enter the routine with a
CALL from BASIC or a G command
from the monitor.
7 6
LOW BYTE
OUTPUT
4 3
— i — I I I f
ASCII CODES USE BITS 1-7 I
MOTION CODES USE ALL 8 BITS-
HIGH BYTE
1 1 1
MOTION DISTANCE
MOST SIGNIFICANT
DATA BITS (0-4)
1 1 1
STROBES:
-PRINT CHARACTER
MOVE PRINT CARRIAGE
Fi D PAPER
INPUT
7
HIGH
6
3YTE
5
4
3
2
1
STATUS FLAGS:
PRINTER READY
PLATEN READY
CARRIAGE (POSITION) READY-
PRINT HEAD READY
Getting a Copy of the Driver
A driver code is rather long for
publication. In any case, typing it in
is a masochistic form of entertain-
ment. To alleviate these problems, I
have made this code available on
5-inch floppy disk. The disk includes:
• object code assembled at hexa-
decimal location 9000 (for 48 K-byte
systems), and hexadecimal location
5000 (for 32 K-byte systems)
• source code in a text file
Also included is a version of this code
adapted for use with Sprint 5 printers
interfaced through Apple's Serial In-
terface Card.
To obtain your copy of this floppy
disk, send a check for $14.95 (Califor-
nia residents add 6% sales tax) plus
$1.00 shipping and handling to Con-
tech, 1111 Pippin Creek Ct, San Jose
CA 95120. Ask for the "Picture-
Perfect Apple" software. ■
Figure 3: The form in which the driver
described in the text communicates with
the Qume Sprint Micro 3 plotter. A strobe
consists of a "1" bit in the appropriate
position, with all other bits "0." If all
strobes are raised simultaneously, the
printer is reset and the print carriage
moves to the left margin.
Figures 4a, 4b, and 4c: Three examples of Apple II high-resolution graphics transcribed
by the Qume Sprint Micro 3 plotter, using the driver described in this article.
234 January 1981 © BYTE Publications Inc
Poking Data Into the High-
Resolution Screen Area
Direct interaction with the
Apple II high-resolution screen
memory is an excellent way to
test addressing schemes and ex-
plore the structure of Apple
graphics images. To experiment
on your own, get into the
monitor mode (type CALL
— 155) and display the high-
resolution screen by typing:
C050 C054 C057
resolution screen. To clear it of
garbage, fill it with Os by typing:
2000:0 2001 < 2000.3FFEM
followed by a return. Once you
have a clean screen, type a hexa-
decimal address followed by a
colon and FF. For example:
2000-.FF
followed by a return. This will set
the byte to all Is and will produce
and hit the Return key. You are a 7-dot-wide line segment at the
looking at page 1 of the high- appropriate place on the screen.
4b
4c
Circle 151 on inquiry card.
Have some
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memories.
16K PROM boards.
■ PROM card has 2708-type memory
■ Quality board construction ■ 0-4 wait states
■ Address any 4K group to any 4K boundary
■ Control up to 8 banks of memory ■ Fully
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Expandable 5 MHz RAM boards.
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memory runs at 5MHz ■ Fast 250 ns access
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any 4K boundary ■ Quality board construction
PRICE— 8K— $175; 16K— $315; 24K— $475;
32K— $620; 8K add-on kits— $135
(California residents add 6% sales tax)
Call or write Artec for details
rlRTGC eLGCTROnOJMC
605 Old County Rd., San Carlos, CA 94070
Telephone (415) 592-2740
January 1981 © BYTE Publications Inc 235
FOR TRS-80* MODEL I USERS ONLY
16 Times
Normal Speed
*TRS-80 is a trademark of Tandy Coip.
High speed load TRS-80* Level II cassettes
Input 15K byte Level II program in 15 seconds
Search BASIC or SYSTEM programs by name
Unlike other high speed tape input de-
vices, FASTLOAD uses standard format
cassettes. Therefore, there is no need to
re-record on other media. At 8000 baud,
FASTLOAD is faster than disk for short
programs. FASTLOAD reads tapes at the
fast-forward speed of the CTR-41 cassette
recorder. The recorder can also be used
for CSAVE at the normal speed.
FASTLOAD connects to the 40 pin I/O or
to the Expansion box. The control program
does not use computer memory because
it is in a built-in PROM. Other valuable
features are keyboard debounce program,
automatic key repeat routine and key-
beep via cassette speaker. Price is $188.00
for FASTLOAD and $95.00 for the modi-
fied CTR-41 recorder.
Personal Micro Computers Inc.
475 Ellis Street, Mountain View, CA 94043 (415) 968-1604
236 BYTE January 1981
Circle 152 on inquiry card.
PM080
Level II 16K at $645
SOFTWARE COMPATIBLE
Reads all Level II BASIC tapes
Reads all SYSTEM tapes
Full range of peripherals
The PMC-80 is a "work-alike" computer
to the popular TRS-80* Model I, Level II
by Tandy, Radio Shack. The PMC-80 has
16K bytes of RAM and the complete
Level II 12K BASIC ROM by Microsoft
that makes it 100% software compatible
with programs from Radio Shack and
from the hundreds of other independent
suppliers. The built-in cassette player
reads standard Radio Shack programs
fortheTRS-80r
Sold through computer stores.
Video output for monitor and TV
Optional FASTLOAD at 8000 baud
Optional Upper/Lower case
The PMC-80 will operate with any of the
many peripherals Radio Shack and
other independent vendors have in-
vented to plug into the TRS-80.* Most
importantly, the Interface Adapter per-
mits Expansion Interfaces with memory
expansion to 48K to be added. An
Expansion Interface will also permit the
addition of Radio Shack compatible
5 Va " disks and disk operating systems,
RS 232, printers, etc.
"TRS-80 is a registered trademark of Tandy, Radio Shack.
Personal Micro Computers, Inc.
475 Ellis Street, Mountain View, CA 94043
(415) 9620220
Circle 152 on inquiry card.
BYTE January W*l 237
Micrograph
Part 3: Software and Operation
E Grady Booch
4314 Driftwood Dr
Colorado Springs CO 80907
Some background on interactive
computer-graphics systems was pre-
sented in Part 1. In Part 2, a descrip-
tion was given of the hardware for a
low-cost color-graphics display pro-
cessor, called Micrograph, which in-
terfaces to a microcomputer as an in-
telligent peripheral device. In this, the
third and final part, you will become
familiar with the software for Micro-
graph, which implements the display-
processor instruction set introduced
in Part 1, and be given instructions
for operating the system.
Software Perspective
Two packages of software are re-
quired to support Micrograph, as we
have observed in the generalized
graphics system in Part 1. The first
package is the applications software,
which executes in the host computer.
This software creates and manipu-
lates abstractions of images. The
elements of these images are de-
scribed to the display processor
through the instructions in a display
list. Within the display processor
itself, there must reside a second soft-
ware package that converts these in-
structions into a visible image.
In Part 1, we described one such in-
struction set for controlling a color
raster-scan display processor, and it
is summarized in table 1, here, in Part
3. Since emphasis has been on the
display processor, and since the ap-
plications software is system specific,
the remainder of this article will con-
centrate upon the other package: the
software internal to the display pro-
cessor. However, the protocol soft-
ware in the host computer that is
needed to carry out communication
with Micrograph will be described.
Mnemonic
Name
CALL
Call subroutine
LCRAM
Load color memory
LPIX
Load pixel
LREG
Load register
LSUB
Load subroutine
LSYM
Load symbol
MOV
Move
RCRAM
Read color memory
RET
Return
RPIX
Read pixel
RREG
Read register
Read subroutine
RSUB
RSYM
Read symbol
SYM
Display symbol
VEC
Draw a vector
WAIT
Wait
Diagnostics are available under XERR.
Table 1:
Sum
mary of graphics
primitives.
These
instructions control
the graphics-dii
play processor in
Micrograph
Software Description
The source software for
Micrograph consists of approxi-
mately 2400 lines of Z80 assembly-
language code plus internal com-
ments. (See listing 2 in Part 1, BYTE,
November 1980, page 280; listing 1 in
Part 2, BYTE, December 1980, page
327; and listing 1, in this issue, page
240.) This code assembles to approx-
imately 2.6 K bytes of object code
and resides in the three system
EPROMs (erasable programmable
read-only memories) in the address
space decimal to 3071.
The Micrograph software was
written on a Zilog Development
System and conforms to the Zilog
Z80 assembly-language standards.
Structured programming and step-
wise refinement were used to develop
the software. By virtue of these
techniques, once I had cleared out the
typos in the source, I required only
four assemblies to complete the final
working package.
Software Structure
Figure 1 (on page 264) indicates
that, as a result of stepwise refine-
ment, the Micrograph software is
highly structured. The software con-
sists of one main routine, three driv-
ing modules, seventeen routines that
implement the instruction set, twelve
shared utility routines, and five inter-
rupt-service routines. These routines
appear grouped together by their
class, then alphabetically in the soft-
ware source listing.
The routine MAIN drives the entire
Micrograph software and handles a
call to the power-up INIT (initializa-
tion). MAIN then enters an infinite
loop of instruction fetches (via
FETCH) and executes (via EXEC). In
this sequence, Micrograph requests
an instruction from the host com-
puter and executes it. PRIMAT is
then called by EXEC to calculate
which instruction has been com-
manded and, in turn, calls the ap-
propriate routine that processes the
various options of the instruction.
These sixteen routines (CALLS
through WAIT) correspond directly
to the instruction set in table 1. Since
the routines execute similar code,
they may call any of several utility
routines. These routines include null
subroutine calls (GUSER and USER),
routines for communicating with the
host computer (GETBLK, SENDBK,
and SENDBY), and some primitive
Text continued on page 260
238 January 1981 © BYTE Publications Inc
COLLECTOR E
ITION
I
M^HtwawLv;...
VERS
The Byte Covers shown at left are available as
Collector Edition Prints. Each full color print is:
• 1 1" X 14" including a 1 W border.
• Part of an edition strictly limited to only 100
prints.
• Personally inspected, signed and numbered
by the artist, Robert Tinney.
• Accompanied by a Certificate of Authenticity.
• Carefully packed and shipped first class.
• Priced at $20, plus $3 ($6 overseas) for post-
age and handling. If Set 1-4 or Set 5-8 is
ordered, the price for all 4 prints is only $70.
To order, use the coupon below. Visa or Master-
Charge orders may call Toll Free.
r Please send me the following Collector Edi
tion Byte Covers and Certificates of Authen-
ticity.
Qty. Cover Amount
#1-7 Bridges of Konigsberg $20
#2-Fun and Games $20
#3-Homebrew $20
#4-Sottware Mirage $20
#5-Computer Engineering $20
#6-Total Eclipse $20
#7-Computer Hardware $20
#8-Perspectives $20
No.s 1-4 $70
No.'s 5-8 $70
Post. & hand. ($3 in US , $6 overseas) $
Total
□ I have enclosed check or money order
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Expiration Date
Send my print(s) to:
Name
Address
City
State_
-Zip-
Mail this coupon to:
robert tinney graphics
1864 N. Pamela Dr.
Baton Rouge, LA
"Of) WS/ ^~ _ 70815
" MV8 "l*E BQ
; ^ Dayi
Circle 153 on inquiry card.
TOUGHEST
BOARDS
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FOR S-100's
Monitor and control
in wicked environments.
Want to put your S-100 system to
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Dual Systems has all the boards it
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D/A board. Four independent channels.
12-bit precision. Input is binary or 2's com-
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back-up preserves data a year. 200 ns
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$590. 16K bytes $990.
CMOS clock board. On-board battery
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We also provide complete main-
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Contact Dual Systems Control
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Listing 1: The final third of the firmware for Micrograph control, written for the Z80
microprocessor used in the prototype. The first and second portions of the firmware ap-
peared with Part 1 and Part 2 of this series.
Q7EA
El
1861
POP
HL
(RESTORE H AND 1.
D7EB
FDE1
1662
POP
IK
SRESTORE )Y
07ED
Fl
18 63
POP
AF
; RESTORE STACK
0VEL
C9
166 4
1865 .
P.E1
1666
CLIP
-: v. ¥. $ a ;
**:******:*««
¥. S * 3 *
» « k « * * « s * * * « « * ft *■ k * * x a? * * «
1867
1668
C.L If
DETERMIN
SHOULD BE CLIPPED OR NOT
1869
CLIP
"IRST
DETERMINES
THE F
OINT REFERENCED, THEN
1870
COMPARES IT WITH THE CASE.
SUCCESS IS SET IN THE
1871
POINT
IS NOT CLIPPED.
1672
1873
CALLS
NONE
1874
1875
CALLED
1876
PUT
ie?7
RPIX
1878
LP IX
1679
1680
REG I J
TERS
H
(TEMPORARY)
1881
B
(CASI
:>
1 882
C
(SUCCESS)
1883
D
(TEMPORARY)
1684
E
(TEMPORARY)
1885
H
(TEMPORARY)
1686
L
(TEMPORARY)
1887
IX
(INDt
:x>
1888
1Y
(INDEX)
1889
1690
1/0
NONE
1891
1892
STRUCTU
GDRO
(X)
1893
GDR1
(Y)
1894
GDR6-13
(VIEWPORTS)
1895
REF
(REFERENCE)
1896
07EF"
0L01
1697
;lips
LD
C, 1
(ASSUME SUCCESS
7F1.
DDCB434E
1898
B I T
1 , (IX+REF)
(POINT TO REFERENCE
D7F5
00
1899
RET
N7
(RETURN IF SET
07F6
F5
1900
PUSH
AF
(SAVE A AND F
D7F7
FDE5
1901
PUSH
1Y
(SAVE IY
07F9
E5
1902
PUSH
HI-
(SAVE H AND L
07FA
[)5
1903
PUSH
DE
(SAVE D AND E
07FB
0E00
1904
LD
CO
(CLEAR SUCCESS
07FD
FD218610
1905
LD
I Y, STRUCT +GDR6
(LOAD REFERENCE START
0801
DDCB4346
1906
BIT
0, (IX+REF)
(TEST REFERENCE
0605
2804
1907
JR
Z.CLIPO
(JUMP IF NOT SET
0807
FD218A10
1908
LD
IY.STRUCT+GDR10
(LOAD REFERENCE START
obob
FD6E00
1909
;lipo:
LD
L, (IY+0)
(LOAD LEFT X
OBOE
2600
1910
LD
H,0
(CLEAR H
0610
Cf.D9
1911
SET
3,C
(SET BIT 3
0812
DD5E0
1912
LD
E, (IX+GDRO
(GET X
0615
1600
1913
LD
0,0
(CLEAR D
0817
AF
1914
XOR
A
(CLEAR CARRY
0818
ED52
1915
SBC
HL.DE
(SUBTRACT
081A
FA2108
1916
JP
I'I,CLIP1
(JUMP IF MINUS
081D
2802
1917
JR
Z, CI I PI
(JUMP IF ZERO
08 1F
CB99
1.918
RES
3,C
(SET BIT 3
0621
FD6E02
1919
:lipi :
LD
L, ( IY-12)
(LOAD RIGHT X
0824
2600
1920
LD
H,0
(CLEAR H
OS 24
CBD1
1921
SET
2 7 c;
(SET BIT 2
08 28
DD5E00
1922
LD
E, (IX + GDRO
(GET X
082B
1600
1923
LD
D ,
(CLEAR D
082D
AF
1924
XOR
A
(CLEAR CARRY
062E
E052
1925
BBC
HL.DE
(SUBTRACT
U830
FA3508
1926
JP
M.CLIP2
(JUMP IF MINUS
0633
CE91
1927
RES
2,C
(RESET BIT 2
0835
FD6E01
1928
:LIP2:
LD
l , ( t y n )
(LOAD LEFT Y
0636
2600
1929
LD
H,u
(CLEAR H
083A
CBC9
1930
SET
1,C
(SET BIT 1
063C
DD5E01
1 931
LD
E, (IXl GDR1
(GUI Y
083F
1600
1932
LD
D , 1]
(CLEAR D
0841
AF
1933
XOR
A
(CLEAR CARRY
0842
ED52
1934
SBC
HL.DE
(SUBTRACT
0844
FA4B08
1935
JP
M.CLIP3
(JUMP IF MINUS
8 4 7
280 2
.1936
JR
Z, EL IP 3
(JUMP IF ZERO
0849
CB89
1937
RES
1 ,C
(SET BIT 1
08 48
F DAE 3
1938
:lip3i
LD
L. ( IY+3)
(LOAD RIGHT Y
084E
2600
1939
LD
H,0
(CLEAR H
0850
CBC1
1940
SET
0,C
(SET BIT
0652
DD5E01
1941
LD
E. (IX+GDR1 )
(GET Y
0855
1600
1942
LD
DrO
(CLEAR D
0857
AF
1943
XOR
A
(CLEAR CARRY
0858
ED52
1944
SBC
HL.DE
(SUBTRACT
065A
FA5F08
1945
JP
M.CLIP4
(JUMP IF MINUS
08SD
CB81
1946
RFS
Q.C
(CLEAR BIT
085F
79
1947
:LIP4:
LD
ft,C
(GET C
0840
0E00
1948
LD
CO
(CLEAR SUCCESS
0862
CB46
1949
BIT
1 ,B
(TEST CASE
0864
2014
1950
JR
NZ.CLIP6
(JUMP IF SET
0666
CB40
1951
B I T
0,B
(TEST CASE
0868
2006
1952
JR
NZ, CLIPS
(JUMP IF NOT SET
Listing 1 continued on page 242
240 January 1981 © BYTE Publications Inc
H
N
C.
CQIYIPLITRQNICS
• ••EVERYTHING FOR YOUR TRS-80 •••
TRS-SO Is a trademark of ihr Radio Shac k Division of Tandy Corporation
1980 INCOME TAX PAC
Completely Revised • Latest Tax Tables •Fully Tested • Complete Manual and Documentation
• • The New Version Of The Income Tax Pacs Are Full Of Error Catching Codes • •
• * Making It Impossible To Make An Error • *
— Follow The Simple Step By Step Procedure That Makes Tax Preparation Simple —
r
* INCOME TAX PAC A
FOR LEVEL II 16K
• DOES FORM 1040 and 1040A
• SCHEDULE A ITEMIZED DEDUCTIONS
• SCHEDULE S INTEREST and DIVIDENDS
• OUTPUT TO VIDEO DISPLAY
• SCHEDULE C TAX COMPUTATION
_L.
• INCOME TAX PAC B
FOR LEVEL II with or without Printer, Cassette or Disk. Has all features
of Income Tax A PLUS,
• WORKS WITH LINE PRINTER
• FORMATS FORM 1040 and 1040A FOR TRACTOR FEED FORMS
• SCHEDULE C INCOME FROM A PERSONALLY OWNED BUSINESS
• FORM 2106 EMPLOYEE BUSINESS EXPENSE
n
FORM 1040 (LONG FORM)
FORM 1040A (SHORT FORM)
FORM 2106 EMPLOYEE BUSINESS EXPENSE
FORM 2440 DISABILITY INCOME EXCLUSION
FORM 2441 CREDIT FOR CHILD AND DEPENDENT CARE EXPENSES
FORMS 3903 MOVING EXPENSE ADJUSTMENT
FORM 4797 SUPPLEMENTAL SCHEDULE OF GAINS AND LOSSES
* * PROFESSIONAL * *
INCOME TAX PAC C
• SCHEDULE A ITEMIZED DEDUCTIONS
• SCHEDULE B INTEREST AND DIVIDENDS
• SCHEDULE C PROFIT (OR LOSS) FROM BUSINESS OR PROFESSION
• SCHEDULE D CAPITAL GAINS AND LOSSES
• SCHEDULE E SUPPLEMENTAL INCOME SCHEDULE
• SCHEDULE G INCOME AVERAGING
• SCHEDULES R & RP-CREDIT FOR THE ELDERLY
FOR MODEL I (32K) or MODEL II (64K)
WITH 1 OR MORE
DISK DRIVES
kLL SPECIFICATIONS SUBJECT TO CHANGE
• SCHEDULE SE-COMPUTATION OF SOCIAL SECURITY SELF-EMPLOYMENT TAX
• SCHEDULE TC TAX COMPUTATION
• OUTPUT TO VIDEO OR LINE PRINTER
• FORMATS FOR TRACTOR FEED OR INDIVIDUAL FORM FEED PRINTERS
• AUTOMATIC MEMORY STORAGE FOR INCOME TAX PREPARERS
• INSTANT LINE CHANGE
• BUILT IN ERROR CHECKING
•CQMPJTRQNICS
■ v \A T *-«*vUi"* .a
50 N. PASCACK ROAD
SPRING VALLEY, NEW YORK 10977
PLEASE SEND ME:
□ INCOME TAX PAC A (S19 95)
D INCOME TAX PAC B ($49.95)
D PROFESSIONAL INCOME TAX PAC C (S99 95)
O MODEL II PROFESSIONAL INCOME TAX PAC C (S199.95)
NEW TOLL-FREE
ORDER LINE
(OUTSIDE OF NY. STATE)
(800) 431-2818
* A COMPLETE LINE OF NELCO TAX FORMS
ARE AVAILABLE
• INDIVIDUAL FEDERAL and STATE FORMS
• 2 OR MORE PART FORMS
• TRACTOR FEED FORMS
• PLASTIC OVERLAYS
■k All orders processed within 24-Hours
•k 30-Day money back guarantee on all Software
• Add $2.00 for shipping in UPS Areas
• Add $3.00 for COD. or NON-UPS Areas
• Add $4.00 outside U.S.A., Canada & Mexico
CREDIT CARD NUMBER
SIGNATURE
.EXP DATE
NAME.
STREET.
CITY.
.STATE.
.ZIP.
Circle 154 on Inquiry card.
HOUR
24 ORDER
LINE
(914) 425-1535
BYTE January 1981 241
Circle 155 on inquiry card.
MTI stocks 'em
for faster deli vc
all]
No hidden charges. Prices include delivery.
VISA and MasterCard orders accepted.
VIDEO TERMINALS
1695
2295
.
ADM-31 (2 page buffer)
«
ADM-42 (8 page buffer avail.)
»
825
1420 (dumb terminal)
895
1421 (Consul 580 & ADM-3A comp.)....
895
1045
1510 (buffered)
1145
1395
1552 (VT-52 compatible)
1350
300 BAUD TELEPRINTERS
LA34-DA DECwriter IV
1045
1295
..1085
LA34-AA DECwriter IV
1225
Diablo 630 RO
2295
Diablo 1640 RO
3085
Diablo 1640 KSR
3285
Diablo 1650 RO
3185
Diablo 1650 KSR
3385
Tl 743 (portable)
1190
1585
Tl 745 (portable/built-in coupler)
Tl 763 (portable/bubble memory)
2690
Tl 765 (port/bubble mem/b-i coupler)
2895
600 BAUD TELEPRINTERS
Tl 825 RO impact
1565
Tl 825 KSR impact
1645
Tl 825 RO Pkg.
1750
Tl 825 KSR Pkg
1R95
1200 BAUD TELEPRINTERS
LA120-AA DECwriter III (forms pkg.l
. 2410
LA180 DECprinter I
. 2195
Tl 783 (portable)
1745
2395
Tl 787 (port/internal modem)
. 2845
Tl 810 RO impact
1800
Tl 810 RO Pkg
. 2047
Tl 820 KSR impact
. 1895
Tl 820 KSR Pkg
1995
Tl 820 RO
1895
. 2047
Tl 820 RO Pkg
2400 BAUD
Dataproducts M200 (2400 baud) . ..
.2595
DATAPRODUCTS LINE PRINTERS
B300 (300LPM band)
. 5535
B600 (600LPM band)
6861
2230 (300LPM drum)
7723
2260 (600LPM drum)
9614
12655
2290 (900LPM drum)
ACOUSTIC COUPLERS
A/J A242-A (300 baud orig.)
242
315
A/J 247 (300 baud orig.)
A/J AD342 (300 baud orig./ans.l
395
A/J 1234 (Vadic compatible)
895
695
A/J 1245 1300/1200 Bell comp.)
MODEMS
GDC 103A3 (300 baud Bell)
395
565
.. 850
GDC 202S/T (1200 baud Bell)
GDC 212-A (300/1200 baud Bell)
A/J 1256 (Vadic compatible)
825
MS
CASSETTE STORAGE SYSTE
...1050
Techtran817 Istore/for/speed up)
1295
Techtran 818 (editing)
. 1795
2295
MFE 5000 (editing)
. 1495
FLOPPY DISK SYSTEMS
Techtran 950 (store/forward)
. 1395
Techtran 951 (editing)
1995
"Please call for quote.
Applications Specialists & Distributors
Great Neck, New York/Cleveland
Ohio.
N.Y.: 516/482 3500 & 212/895-7177
k 800/645-8018 Ohio: 216/464 6688
Listing
1 continued:
086A
FEDA
1953
CP
10
JTEST IF 10
086C
2820
1954
JR
Z, CLIPS
;JUMP IF EQUAL
086E
1822
1955
JR
CLIP9
JJUMP AROUND
0870
FE08
1956 CLIPS: CP
8
JTEST IF 8
0872
2B1A
1957
JR
Z.CLIPS
;JUMP IF SO
0874
FE0B
1958
CP
11
;TEST IF 11
0B76
2816
1959
JR
Z, CLIPS
;JUMP IF SO
0878
1818
1960
JR
CLIP9
;JUMP AROUND
087A
CB40
1961 CLIP6: BIT
0,B
JTEST BIT
087C
200A
1962
JR
NZ,CLIP7
;JUMP IF SET
oe7E
FE02
1963
CP
r>
JTEST IF 2
0880
280C
1964
JR
Z, CLIPS
JJUMP IF SO
0882
FE0E
1965
CP
14
JTEST IF 14
0884
2808
1966
JR
Z, CLIPS
JJUMP IF SO
0886
180A
1967
JR
CLIP9
JJUMP AROUND
0888
FE05
1968 CLIP7: CP
5
JTEST IF 5
088A
2002
1969
JR
NZ.CLIP8
JJUMP IF NOT SO
088C
1804
1970
JR
CLIP9
J JUMP AROUND
08SE
0E01
1971 CLIPS: LD
C, 1
JSET SUCCESS
0890
1802
1972
JR
CLIP10
JJUMP AROUND
0692
0E00
1973 CLIP9: LD
CO
JCLEAR SUCCESS
0894
Dl
1974 CLIP10: POP
DE
JRESTORE D AND E
0895
El
1975
POP
HL
JRESTORE H AND L
0896
FDE1
1976
POP
IY
JRESTORE IY
0898
Fl
1977
POP
AF
JRESTORE AF
0899
C9
1978
1979
RET
J RETURN
1980
GETBLK ***
**********
*********
***********************
1981
1982
GETBLK READS B BYTES
OF DATA
AND PLACES THE DATA
1983
STARTING AT HL.
1984
1985
CALLS
FETCH
1986
1987
CALLED BY
LCRAM
1988
LSUB
1989
LSYM
1990
1991
REGISTERS
A
(DATA)
1992
B
(COUNT)
1993
H
(POINTER)
1994
L
(POINTER)
1995
1996
I/O
NONE
1997
1998
STRUCTURES
NONE
1999
089ft
CDED01
2000
3ETBLK: CALL
FETCH
JCALL FETCH
089D
77
2001
LD
<HL),A
J SAVE THE DATA
089E
23
2002
TNC
HL
J INCREMENT THE POINTER
039F
05
2003
DEC
B
JDECREMENT THE COUNT
0SA0
20FB
2004
JR
NZ, GETBLK
JJUMP IF NOT DONE
08A2
C9
200S
2006
RET
J RE TURN
2007
GUSER ****
**********
*********
**•::********************
20U8
2009
GUBER IS THE DEFAULT
GRAPHICS
SUBROUTINE WHICH IS
2010
THE DUMMY
CALL FORM
THE PRIMITIVE CALL. GUSER SlflPL
201 1
RETURNS.
2012
2013
CALLS
NONE
2014
2015
CALLED BY
CALLS
2016
2017
REGISTERS
NONE
2018
2019
I/O
NONE
2020
2021
STRUCTURES
NONE
2022
08A3
80
2023
2024
iUSER: DEFB
128
JRETURN FROM GRAPHICS
2025
PEEK *****
**********
*********
*********************** T
2026
2027
PEEK READS
DATA FROM
A PIXEL.
PEEK FIRST SETS A READ
2028
FLAG, CALLS PIXEL, THEN RETURNS. PEEK EXPECTS THE
2029
PIXEL TO BE AT XY. THE COLOR
IS RETURNED IN ft.
2030
2031
CALLS
PIXEL
2032
2033
CALLED BY
RPIX
2034
2035
REGISTERS
A
(COLOR
RETURN)
2036
C
(READ FLAG)
2037
2038
I/O
NONE
2039
2040
STRUCTURES
NONE
2041
08A4
0E01
2042 1
•EEK: LD
C, 1
JSET REftO FLAG
08A6
CDAA08
2043
CALL
PIXEL
JGET THE DATA
08A9
C9
2044
2045
RET
J RETURN
2046
PIXEL ****
**********
*********
***********************
2047
2048
PIXEL MAPS
THE USER
I00RDINATE DATA TO THE PHYSICAL
2049
SYSTEM. THIS IS PERHAPS THE MOST COMPLEX ROUTINE IN
205D
THE FIRMWARE, AND IS
THE ONLY
ROUTINE THAT MUST
Listing 1 continued on page 244
242 January 1981 © BYTE Publications Inc
DEALERS: By now you know that it takes
SOFTWARE
TO SELL
COMPUTERS
and International Micro Systems can provide you with the largest selection of quality business
applications ever developed for the microcomputer industry.
If you are just looking for a G.L., A/P, and Payroll, you can find them in a dozen ads in this
magazine. But thers's a much bigger market for micros out there than that. Where can you find a
fully interfaced Wholesale/Retail Distribution System? How about Manufacturing Inventory
Control including Production Scheduling & Control. See that one anywhere else? Maybe your
market is Medical/Dental and IMS has the full systems there too. You can't sell computers
without software and IMS has the finest selection of software available foryou. Each system has
been developed by the IMS professional staff and we support what we sell.
But thats not all. International Micro Systems has the strongest dealer marketing plan in the
industry. With our
$ 245 Dealer Demo System.
we put all the software shown below in your office or store ready to demo to your prospects and
we include the promotional material and our unique video sales presentation to help you move
systems. Give us a call or drop us a card and let us show you what selling business systems
should be all about.
Financial Systems
GL. A/P, A/R
Payroll
Cash Receipts/Disb.
Job Costing
Mailing List Mgmt.
Medical/Dental
Office.Scheduler
Patient Billing 4 AVR
Insurance Forms
Governmental/Educational
Student Record Keeping
and Scheduling
Fund Accounting
Wholesale Distribution System
Purchasing & Receiving
Inventory Control
Invoicing & Receivables
Salesman Comm. Reporting
Backorder Management
Manufacturing Inventory Control
Finished Goods Inventory Mgmt.
Parts Inventory Mgmt.
Parts Purchasing & Receiving
Bill of Material
Production Scheduling
INTERNATIONAL
IICRO
S
YSTEMS
For details on our demo special, contact us at:
8425 Quivira Road, Lenexa, Kansas 66215
Phone: (913) 888-8330
Circle 156 on inquiry card.
BYTE January 1981 243
Circle 157 on inquiry card .
SUPERBRAIN
32K or 64K (Double or Quad Density units
available). Uses two Z-80 CPU's. Commercial-
type terminal with 12" monitor. Dual double
density minifloppies. Over 350 kilobytes of
storage (twice that with quad density drives).
Two serial RS232 ports, I/O ports standard.
Expandable with optional S-100 S-100 inter-
face. Comes with CP/M™ 2.2 operating sys-
tem. MiniMicroMart includes BASIC inter-
preter and can supply a wide range of CP/M
Development and Application software.
w/32K Double Density, List $2995 . $2685
w/64K Double Density, List $3345 $2883
w/64K Quad Density, List $3995 $3595
64K Special Quad Version $3395
INTERSYSTEMS
formerly ITHACA AUDIO
DPS-1, List $1795
Call for Price!
The new Series II CPU Board features a 4 MHz
Z-80A CPU and a full-feature front panel. 20-
slot actively terminated motherboard, with 25
amp power supply (50/60 Hz operation, incl.
68cfmfan).
COMPLETE SYSTEM with InterSystem 64K
RAM, I/O Board w/priority interrupt and
double density disk controller board. Full 1-year
warranty, List $3595
HEWLETT-PACKARD
HP-85A
F.O.B. shipping point. All prices subject to change and all
offers subject to withdrawal without notice. Advertised prices
are for prepaid orders. Credit card and C.O.D. 2% higher.
C.O.D. may require deposit.
- WRITE FOR FREE CATALOG -
MiniMicroMart
1618 James Street
Syracuse, IMY 13203 (315) 422-4467
Listing 1 continued:
OBAA
08AC
OBAD
08AE
OSAF
03B2
Dee. 4
uae.i
08BS
081} A
0BBD
08BF
08C2
08 CS
oecs
DSC 9
oacft
C8CC
0BCE
08D1
08D3
0SD5
08D7
08D9
D8DB
08DD
06DF'
08E1
0BE4
OSES
D8EB
08EA
obec;
08EE
0BF0
08F2
08F3
08F4
08F5
08F7
08F9
D8FB
08FD
Q8FF
0901
0903
090S
0907
0909
090B
090C
090D
0V0F
0910
0911
0912
0911
0916
0918
091A
09 1.C
09 IE
09 If
0920
0921
0922
0923
0921
FDE5
E5
05
F5
DD7E0E
E6E0
FE00
280 D
Ft CO
CA4209
F EE0
CAB709
C39000
DD7EQ1
2F
67
CB3C
CB3C
DD6E00
CB3C
CB1D
CB3C
CB1D
CB3C
CB1D
CB3C
CB1D
110020
19
DD7E00
E60C
CB3F
CB3F
CB41
2B1E
IF
Fl
7E
CB41
2301
CB27
CB27
CB4 9
2808
CB27
CB27
CB27
CBS 7
E6C0
Dl
El
FDE1
C9
4F
f 1
163F
E6C0
CB41
2E0A
CB3F
CB3F
FS
7 A
OF
01
57
F 1
CB49
2051
2052
2053
2054
2055
2056
2057
205B
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2073
2079
2080
2081
2082
2083
2084
2085
2086
21.187
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
23?'/
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
21.10
2111
2112
2113
2114
2115
2116
2 1 1 7
2118
2119
2120
21.21
2122
2123
2124
2125
2126
2127
2128 PIXEL
2129
2130
2131
2132
2133 PIXEL
2134
2135
2136
2137
2138
2139
2140
2 1 4 1
214 2
2143
2144
2145
2146
21.47 PIXEL
BE MODIFIED IF SYSTEM II IS USED. PIXEL FIRST
DETERMINES WHAT DISPLAY DENSITY IF USED. AND IF THE
OPERATION IS READ OR WRITE. THE PHYSICAL ADDRESS
OF THE PIXEL IS DETERMINED, THEN THE BIT ADDRESS IS
MAPPED OUT. PIXEL DEALS WITH THE PIXEL AT XY , THE
READ FLAG IN REGISTER C, AND EXPECTS/RETURNS THE
COLOR IN REGISTER A.
CALLS
CALLED BY
REGISTERS
I/O
STRUCTURES
IXELOs I.
PIXEL1 I
NONE
POKE
PEEK
A
c
D
E
H
L
IX
IY
NONE
GDRO
BDR1
GDR14
(COLOR, FLAGS)
(FLAGS, TEMPORARY)
(TEMPORARY)
(TEMPORARY)
(POINTER)
(POINTER)
( INDEX)
(INDEX)
(X)
(Y)
(DISPLAY FORMAT)
PUSH
PUSH
PUSH
PUSH
LD
AND
CP
JR
CP
JP
Cf
JP
JP
D
EPI
LD
SRI.
SRL
LD
SRL
RR
SRL
RR
SRL
RR
SRL
RR
LD
ADD
LD
AND
SRL
SRL.
B I T
JR
LD
POP
LD
BIT
JR
SLA
SLA
BIT
JR
SLA
SLA
BLA
SLA
AND
POP-
POP
POP
RET
LD
POP
LD
AND
BIT
JR
SRL
SRL
PUSH
LD
RRCA
RRCA
LD
POP
BIT
REFRESH RAM
IY
HL
DE
AF
A. (IX+GDRM)
liioaonoi}
u
Z, PIXELJ)
11 000 00 Of.
Z, PIXEL*
11100000EJ
Z.PIXEI...C
XERR
A, < IXK3DR1 )
H,A
H
H
I , ( IX+ODRO)
H
L
H
L
H
L
H
L
DE.RBOTTOM
HLiDE
A, < IX + GDRO)
00001 100B
A
A
O.C
2, PIXELS
C,A
AF
A, <HL>
0,0
Z.PIXEL1
ft
A
1 ,C
Z,PIXEL2
A
A
A
A
11000000B
DE
HL
IY
C,A
AF
D, 001 11 11 IB
11000000B
0,0
7.PIXEL4
A
A
AF
A,D
D,A
AF
1,C
(SAVE IY
(SAVE HL
(SAVE DE
(SAVE AF
;glt display i ormat
(MASK all but type
(64 X 64 ?
(JUMP IF SO
;128 X 128 ?
(JUMP IF 80
125* X 192 ■■■
(JUMP ':-' 80
! ERROR OTHERWISE
(BET Y
: COMPLEMENT
(LOAD H
! SHIFT
; SHIFT
iLOAD X
; SHIFT
! SHI FT
(SHIFT
; SHIF1
; SHI FT
; SHIF'I
(SHIFT
(SHIFT
(LOAD BASE ADDRESS
(ADO OFFSET
(GET X
(MASK ALL BUT 2 BITE;
(SHIFT
(SHIFT
(CHECK READ FLAI3
[JUMP IF NOT SET
(LOAD C
(RESTORE A
(GET PIXEL
(CHECK LSB
(JUMP IF ZERO
(SHIFT A
(SHIFT A
(TEST NEXT BIT
(JUMP IF ZERO
(SHIFT
(SHIFT
(SHIFT
(SHIFT
(MASK ALL ELSE
(RESTORE DE
(RESTORE HL
(RESTORE IY
(RETURN
(SAVE DATA
(RESTORE COLOR
(LOAD A MASK
(MASK COLOR
(TEST READ FLAG
(JUMP IF NOT SET
(SHIFT
(SHIFT
(SAVE AF
(GET THE MASK
(ROTATE RIGHT
[ROTATE RIGHT
[RESTORE THE MASK
[ RESTORE AF
(TEST LSB
Listing 1 continued on page 246
32K Board Pictured Above
Why Not the Best?
From The Dynamic RAM Company.
2MHz
4MHz
16K-$249
$259
32K-S375
$395
48K— $500
$530
64K— $625
$665
We have now been shipping
our 2MHz dynamic RAM boards
for over two years. Hundreds of
4MHz boards have been going
out every month since early
1979. Our reliability is proven in
the thousands of systems which
contain our board. Many quality-
minded systems houses across
the country and overseas are
using our boards for their
equipment.
Our prices still beat all.
Despite rising 1 6K memory chip
prices (at least from reputable
suppliers), Central Data continues
to give you the best buy in
memory today. Nobody offers a
board with a capacity of 64K,
assembled, tested, and guaranteed
for a full year at the price we do.
Circle 158 on Inquiry card.
Deselect around PROMs. Our
boards have the important deselect
feature which lets you overlap any
fixed memory in your system with
no interference.
Our features make the board
easily used and expanded. You
address our boards on 1 6K
boundaries with mini-jumps (small
shorting plugs that slide over wire-
wrap pins) near the top of the
board for easy access. If you want
to expand your board after you
have purchased it, all that you
need to do is add memory. We
can supply you with expansion
packages ($150-2MHz,
$160-4MHz) which include eight
RAMs that you can depend on as
well as two mini-jumps for
addressing. And of course, our
board never generates wait states.
Low power consumption keeps
your computer running cool and
reliable. The total power
consumption of our 1 6K board is
typically less than 4 watts (+8V @
300ma, + 1 6V @ 1 50ma and
-16V @ 20ma). Boards with
additional memory typically
increase power consumption only
1 watt per 1 6K!
Standard S-100 Interface. Our
board is designed to interface with
any standard S-100 CPU. All of
the timing of the board is
independent of the processor chip,
and the board is set up for
different processors by changing
two plugs on the board.
Call or write us today. That will
guarantee a fast response with
more information on the board. Or
make an order — you'll probably
have the board in two weeks! If
you're interested, also ask for a
catalog on our Z8000 16-bit
processor board designed for the
MULTIBUS. All of these products
are available to your local dealer,
also.
Central Data Corporation, 713
Edgebrook Drive, PO Box 2530,
Station A, Champaign, IL 61820.
(217) 359-8010
Central Data
BYTE January 1981
245
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Phone Orders Call 212-465-6609
Listing 1 continued:
0926
2010
2118
JR
Z, PIXELS
[JUMP IF ZERO
0928
CB3F
2119
SRL
A
(SHIFT
092A
CB3F
2150
SRL
ft
ISHIF1
092C
CB3F
2151
SRL
A
; SHIFT
092E
CB3F
2152
BRL
A
; SHI FT
0930
F5
21.53
PUSH
AF
(SAVE AF
0931
7 A
2151
LD
ft.D
(SET THE MASK
0932
OF
2155
RRCA
[ROTATE RIGHT
0933
OF
2156
P. RCA
[ROTATE RIGHT
0931
OF
2157
RRCA
; ROTATE RIGHT
935
OF
2158
RRCA
! ROT ATE RIGHT
0936
5 7
2159
LD
D,A
;GET THE MASK
093"/
Fl
2160
POP
AF
(RESTORE AF
0938
IF
2161 PIXELS: LD
C,A
[SAVE MASK
939
7E
2162
LD
A. (HL)
;get data
093A
A2
2163
AND
D
(MASK THE old
093B
Bl
2161
OR
C
;and data
093C
77
2165
LD
(HL) ,A
[SAVE PIXEL
093D
Dl
2166
POP
DE
(RESTORE DE
093E
El
2167
POP
HL
(RESTORE HL
093F
FDE1
2168
POP
1Y
(RESTORE IY
0941
C9
2169
RET
(RETURN
0912
DD7E01
2170 PIXEL6: LD
A, ( IXhGDRI)
(LOAD Y
0915
2F
2171
CPL
[COMPLEMENT
0916
67
2172
LD
H,A
(LOAD Fl
0917
CB3C
2173
SRL
H
(SHIFT
0919
DD6E00
2171
LD
L. CIX+BDRO)
(LOAD X
091C
CB3C
2175
SRL
H
[SHIFT
091E
CB1D
2176
RR
L
(SHIFT
0950
CB3C
2177
SRL
H
(SHIFT
0952
CB1D
2178
RR
L
(SHIFT
0951
CB3C
2179
SRL
H
(SHIFT
0956
CB1D
2180
RR
L
(SHIFT
0958
110028
2181
LD
DE.RBOTTOM+2018
(LOAD BASE ADDRESS
95B
19
2182
ADD
HL.DE
(ADD OFFSET
095C
DD7E00
2183
LD
A, (IX+GDRO)
(GET X
095F
E606
2181
AND
000001 10B
[MASK ALL BUT 2 BITS
0961
CB3F
2185
SRL
A
(SHIFT
0963
CB11
2186
BIT
o.c
(TEST LSB
0965
281E
2187
JR
Z.PIXEL9
(JUMP IF NOT SET
0967
IF
2ise
LD
C,A
(SAVE A
0968
Fl
2189
POP
AF
(RESTORE A
0969
7E
2190
LD
A, (HL)
(GET PIXEL DATA
096A
CB11
2191
BIT
OrC
(TEST NEXT BIT
096C
2801
2192
JR
Z.PIXEL7
(JUMP IF NOT SET
096E
CB27
2193
SLA
A
(SHIFT
0970
CB27
2191
SLA
A
[SHIFT
0972
CB19
2195 PIXEL7: BIT
IrC
(TEST NEXT BIT
0971
2808
2196
JR
Z.PIXEL8
(JUMP IF NOT SET
0976
CB27
2197
SLA
A
[SHIFT
0978
CB27
2198
SLA
A
[SHIFT
097A
CB27
2199
SLA
A
[SHIFT
097C
CB27
2200
SLA
A
(SHIFT
097E
E6C0
2201 PIXEL8: AND
11000000B
[AND ALL ELSE
0980
Dl
2202
POP
DE
[RESTORE DE
0981
El
2203
POP
HL
[RESTORE HL
0982
FDE1
2201
POP
1Y
[RESTORE IY
0981
C9
2205
RET
[RETURN
0985
1F
2206 PIXEL9: LD
C,A
[RESTORE A
0986
Fl
2207
POP
AF
[RESTORE STACK
0987
163F
2208
LD
D, 001 11 HIE
(GET THE MASK
0989
E6C0
2209
AND
11000000B
(MASK ALL ELSE
09 BE
CB11
2210
BIT
O.C
[CHECK LSB
093D
2S0A
2211
JR
Z, PIXELA
[JUMP IF ZERO
098F
CB3F
2212
SRL
A
[SHIFT
0991
CB3F
2213
SRL
A
[SHIFT
0993
F5
2211
PUSH
AF
[SAVE AF
0991
7A
2215
LD
A,D
(GET THE MASK
0995
OF
2216
RRCA
[R0TA1E RIGHT
0996
OF
2217
RRCA
[ROTATE RIGHT
0997
57
221B
LD
D,A
[RESTORE THE MASK
0998
Fl
2219
POP
AF
[RESTORE THE MASK
0999
CB19
2220 PIXELA: BIT
1 ,C
[CHECK NEXT BIT
099B
2810
2221
JR
Z, PIXELS
[JUMP IF ZERO
099D
CB3F
2222
SRL.
A
[SHIFT
099F
CB3F
2223
SRL
A
[SHIFT
9 A 1
CB3F
2221
BRL
A
[SHIFT
09A3
CB3F
22^5
SRL
A
(SHIFT
09A5
F5
2226
PUSH
AF
(SAVE. AF
09A6
,'n
2227
LD
A,D
[GET THE MASK
09A7
OF
2228
RRCA
[ROTATE RIGHT
09A8
OF
2229
RRCA
[ROTATE RIGHT
09A9
OF
2230
RRCA
[ROTATE RIGHT
09AA
OF
2231
RRCA
[ROTATE RIGHT
09AE:
57
2232
LD
D, A
[RE1 THE MASK
09AC
Fl
2233
POP
AF
[RESTORE AF
09AD
1F
2231 PIXELS! LD
C, A
[SAVE A
09AE
7E
2235
LD
A, (HL)
(GET PIXEL DATA
D9AF
A 2
2236
AND
D
(MASK THE OLD
09B0
Bl
2237
OR
C
(OR WITH C
09B1
77
2238
LD
(HL) ,A
(SAVE PIXEL
09B2
Dl
2239
POP
DE
[RESTORE DE
09B3
El
2210
POP
HL
[RESTORE HL
09B1
FDE1
2211
POP
IY
[RESTORE IY
09B6
C9
2212
RET
[RETURN
09B7
DD7E01
2213 PIXFLC: LD
A, (IXi-GDRl )
[MOVE Y TO A
09BA
2F
2211
CPL
[COMPLEMENT
Listing 1 continued on page 248
246 January 1981 © BYTE Publications Inc
<F,V
.Threaded Interpretive
Languages
R. G. Loeliger
Threaded languages (such as FORTH) are an exciting new class of languages. They are compact
and fast, giving the speed of assembly language with the programming ease of BASIC, and com-
bine features found in no other programming languages. An increasing number of people are
using them, but few know much about how they work. Is a threaded language interpreted or
compiled? How much memory overhead does it require? Just what is an "inner interpreter?"
Threaded Interpretive Languages, by R. G. Loeliger, concentrates on the development of an
interactive, extensible language with specific routines for the ZILOG Z80 microprocessor. With
the core interpreter, assembler, and data type defining words covered in the text, it is possible to
design and implement programs for almost any application imaginable. Since the language itself
is highly segmented into very short routines, it is easy to design equivalent routines for different
processors and produce an equivalent threaded interpretive language for other development sys-
tems. If you are interested in learning how to write better FORTH programs or you want to design
your own powerful, but low-cost, threaded language specific to your needs, this book is for you.
linil
This and other BYTE/McGraw-Hill
books are available from BYTE
Books or your local computer store.
Please send
. copies of Threaded Interpretive Languages
ISBN 0-07-038360-X
Price $18.95
B1
Name
Title
Company
Street
City
Stale/Province
Code
Call TOLL FREE: 800-258-5420
or Mail To:
Bill
k;ii\s 7: "
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I Check enclosed in the amount of $
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Card No.
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Add 75ff per book to cover postage and handling.
Please remit in U.S. funds or draw on a U.S. Bank.
Circle 160 on inquiry card.
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• Optional 951 1 arithmetic processor
• 8-level vectored + non-maskable interrupts
• Two programable timers
• On-board monitor ROM option
• Full "Multimaster" capabilities allow multiple
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same bus
• Flexible and/or hard disk controller
• Powerful disk-based operating system
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Prices start from $998. System discounts.
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• 16biiP-codeCPU
• 64K bytes RAM/Full DMA
• Floppy disk controller (SS or DS)
• Floating point hardware (IEEE standard)
• System software with enhancements
• 2 serial, 2 parallel ports
• Pascal compiler. text editors, file manager,
CPU & memory diagnostics, symbolic Pascal debugger.
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Floppy Disk Drives (2)
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With CPU
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System discounts
ADM3A+ plus RG graphics (512x256). ..$1995
NEC Spinwriter 5510 or 5530 w/trac 2895
Anadex DP-9500 printer (60dpi) 1595
X-912 CRT (less 18 function keys) 799
P-E 550 CRT ("Bantam") 740
Siemens standard 8" drive (ss/sd-dd) .... 399
312 684-3183
^^" COMPUTEX
J^L \ Microcomputer Sy»t ems \
^^\ \ 5710 Drexel, Chlcigo, IL 60637
Listing 1 continued:
09BB
67
2245
LD
H,A
SAVE IN H
9BC
DD6E00
2246
LD
L, (IX+GDRO)
GET X
09BF
CB3C
2247
SRL
H
SHIFT H
09C1
CB1D
2248
RR
L
SHIFT L
09C3
CB3C
2249
SRL
H
SHIFT H
D9C5
CB1D
2250
RR
L
SHIFT L
09C7
CB3C
2251
SRL
H
SHIFT H
09C9
CB1D
2252
RR
L
SHIFT L
09CB
110018
2253
LD
DE,RE0TT0M-2048
POINT TO BOTTOM
09CE
19
2254
ADD
HL. ,DE
ADD OFFSET
09CF
DD7E00
2255
LD
A, (IX+GDRO)
GET X
09D2
E607
2256
AND
00000111B
MASK A
0904
CB41
2257
BIT
0,C
TEST LSB
09D6
2824
2258
JR
2, PIXELS
TEST FOR READ
09D8
4F
2259
LD
C,A
LOAD C
09D9
Fl
2260
POP
AF
RESTORE A
09DA
7E
2261
LD
A,(HL>
GET PIXEL
09DB
CB41
2262
BIT
0,C
•TEST LSB
09DD
2802
2263
JR
Z.PIXELD
SJUMP AROUND SHIFT
09DF
CB27
2264
SLA
A
;SHIFT A
09E1
CB49
2265
=TXEL0:
BIT
1,C
;test next bit
09E3
2804
2266
JR
Z.PIXELE
JJUMP AROUND SHIFT
09E5
CB27
2267
SLA
A
JSHIFT A
09E7
CB27
2268
SLA
A
;SHIFT A
09E9
CB51
2269
••IXELE;
BIT
2,C
;TEST NEXT BIT
09EB
2808
2270
JR
Z.PIXELF
;JU«P AROUND SHIFT
09ED
CB27
2271
SLA
A
(SHIFT A
09EF
CB27
2272
SLA
A
; SHIFT A
09F1
CB27
2273
SLA
A
JSHIFT A
09F3
CB27
2274
SLA
A
; SHI FT A
09F5
E680
2275
E'lXELF:
AND
100000O0B
(MASK ALL OTHERS
09F7
Dl
2276
POP
DE
; RESTORE DE
09F8
El
2277
POP
HL
RESTORE HL
09F9
FDE1
2278
POP
IY
(RESTORE IY
09FB
C9
2279
RET
; RETURN
09FC
4F
2280
='IXELG:
LD
C,A
■SAVE DATA
09FD
Fl
2281
POP
AF
;GET COLOR
09FE
167F
228^
LD
d. om hub
[LOAD THE MASK
oaoo
E680
228 3
AND
loooooaoB
•MASK ALL EL8E
DA02
CB41
2284
BIT
o,c
■TEST LSB
0A04
2807
2285
JR
Z.PIXELH
JUMP AROUND SHIFT
0A06
CB3F
22E6
SRL
A
SHIFT
0A08
F5
2287
PUSH
AF
SAVE AF
0A09
7A
2288
LD
A,D
GET THE MASK
0AC1A
OF
2289
RRCA
ROTATE RIGH1
0A0B
57
2290
LD
D,A
GET THE MASK
0A0C
Fl
2291
POP
AF
RESTORE AF
0AOD
0B4 9
2292
"•1.XELH:
BIT
1,C
TEST NEXT BIT
0A0F
280A
2293
JR
Z,PIXELI
JUMP AROUND SH.TI- r
0A11
CB3F
2294
SRL
A
SHIFT
UAli
CB.5I-"
2295
SRL
A
SHIFT
D a i :,
F 5
2296
PUSH
AF
SAVE AF
0A16
7rt
2297
LD
A»D
GE ' 1 HE MASK
0A1V
or
2296
RRCA
ROTATE R1GK1
0A18
OF
2299
RRCA
ROTATE RIGHT
0A1V
57
2300
LD
D , A
GET THE MASK
0A1A
Fl
2301
POP
AF
RESTORE AF
0A1B
CB51
2302
'■1XLL.1 :
B 1 T
2,C
TES'I NEXT Bl"!
GA1D
2810
2303
JR
Z, PIXEL J
JUMP AROUND SH ' F r
0A1F
CB3F
2304
SRL
A
SHIFT
0A2t
CB3F
2305
SRL
A
SHTFT
0A23
CB3F
2306
SRL
A
SHIFT
0A2S
CB3F
2307
SRL
A
SHIFT
0A27
F5
2308
PUSH
AF
SAVF, AF
0A28
7 A
2309
LD
A , D
GET THE MASK
0A29
OF
2310
RRCA
ROTATE RIGHT
DA2A
OF
2311
RRCA
ROTATE RIGHT
0A2B
OF
2312
RRCA
ROTATE RIGHT
0A2C
(IF
2313
RRCA
ROTATE RIGHT
0A2D
57
2314
LD
D,A
GET HIE MASK
0A2E
F 1
2315
POP
AF
RESTORE AF
0A2F
4F
2316
'IXELJ:
LD
C, A
SAVE A
0A3Q
7E
2317
LD
A , ( HL )
GET PIXEL
0A31
A2
2318
AND
D
MASK THE OLD PARI
0A32
Bl
2319
OR
C !
OR DATA
0A33
77
232D
LD
(HL),A
SAVE PIXEL
0A34
Dl
2321
POP
DE !
RESTORE DE
0A35
El
2322
POP
HL
RESTORE HL
0A36
FDE1
2323
POP
IY i
RESTORE IY
0A38
09
2324
2325
2326
2327
2328
RET
RETURN
POKE
««««*****««***«**«********
***********«**«*««
POKE
WRITES DATA TO THE PIXEL t
T XY. POKE SETS A
2329
WRITE
FLAG
THEN CALLS PIXEL. TF
E COLOR DATA IS
2330
EXPECTE TER A.
2331
2332
CALLS
PIXEL
2333
2334
CALLED
LPIX
2335
PUT
2336
2337
2338
REGIS
TERS
C (WRITE FL
AG)
2339
2340
I/O
NONE
2341
Listing 1 continued on page 250
248 January 1981 © BYTE Publications Inc
SIRIUS 80+
High Performance
Low Cost Floppy Add-Ons !
The SIRIUS SYSTEMS 80+ Series of Floppy
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COMMON CHARACTERISTICS
■ 5ms track-to-track access lime
■ Auto-Eject
m 180 day WARRANTY
■ Exceptional speed stability - 11l2°k
■ Single/Double Density operation
■ Mix any or all 80+ Series ontbeSS
Standard cable
SPECIFIC CHARACTERISTICS
The SIRIUS 80+1 -a single sided, 40 track
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The SIRIUS 80+2 is a dual sided, 80 track (40
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as TWO 40 track drives yet COST LESS THAN
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since data is recorded on both sides of the
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data storage is 204K/408K Bytes Single/Double
tensity.
SIRIUS 80+2 $449.95
The SIRIUS 80+3 - a single sided, 80 track
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Formatted data storage is 204K/408K Bytes
Single/Double Density.
SIRIUS 80+3 $499.95
The SIRIUS 80+4 -a dual sided. 160 track (BO
per side) 5'/<" monster! The ultimate in state-
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80+4 is seen by the TRS-80* as two single
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one 80+4 is equivalent to 4% standard Radio
Shack drives — at a savings of over 73% (not
to mention diskettes!!!), (with a double den-
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The 80+4 (a 96 tpi drive) includes TRAKS-
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Standard cable. Formatted storage is 408K/
816K Bytes Single/Double Density.
SIRIUS 80+4 $649.95
All 80+ Series Floppy Disk add-ons operate at
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limited to 12ms for the TRS-80*
*TRS-80© ol Tandy Corp.
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I Fast, Linear Voice Coil Positioning
I 10 ms track-to-track positioning
I Fully servoed head positioning
I Dedicated servo track