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PERSONAL COMPUT€R MA©nZIN€ 



1-9826 



Issue No. 7, April 1983: $1.00 



Micro networks . 
tor- sch ools 






NZ-made disk drives 
for System 80/TRS 80 

Winning Sinclair program 

New Sord column | 

plus our usual columns 




:;. . . 



IN JAPAN 

THE NEC PC-OOOO 
OUTSELLS ITS NEAREST 
COMPETITOR DY 2 T0 1 



HERESWHY. 

The PC-8000 Personal 
Computer for Professionals from 
NEC. Prices including a high 
resolution monitor start at 52140. 
The PC-80O0 is a highly reliable 
personal computer ideal for 
applications in business and the 
professions. It features a powerfu 
BASIC, many versatile 
applications packages, excellent 
screen graphics, and high ease of 
use. The PC-8000 can be used as 
a stand-alone computer or as a 
terminal attached to a host 
computer. 

Either a PC-8023A Dot Matrix 

or a letter quality stand alone 

typewriter can be attached to the 
PC-8000. 

THE FACTS I 

PC 8001 B 

PROCESSOR: ,iPC760C-l 1 2-60A compatible-, 

'. MM/| 

MAIN MEMORY*: 32K (32.768) hytcs Dynamic 
haw Memory Heaoily extendable lofri K or lor 
special appl -.Jlionn up 10 192 K. 

flOM MEMORY; 24 K iVtb'Sl bytrtf minimum 
mti.i'.iiiiij M it i oao ' I Basic and Machine Code 
Monitor 

KEYBOARD: 02 Keys typewriter style with 20- Key 
"iimcric I>M. UBB«r/ii»««:r case qr-aptuc and 
1C flnllrie Ouir actors, and conliol Keys. — 5 
piogrtimmahla function keys ■ 2 functions each. 

CLOCK: t me and date can bo *« and road "torn 
programs. Keeps track of year, momti day and 
the exaci time 
ATTRIBUTES: User Programmable SottOn S*W 
3G. SO ?? ev Bfl characters by20oi 25 lines 

2*8 cuiactorsandg'aiyucsvmDob "60 ■ ico 

dois graphic mc-se 6 colours {blac<t. blue red. 
magenta, ween, cyan, yei-'o* or white! 
in intensities, and ■.urcon attribute* (blinking, 
reverse, hidden, etc.) Built in speaker 

INTERFACES: F5K lystem >(:?C0. 2400 Hit. 
£00 baud Standard 8- W paralte) printer Interlace. 
Serial Interface •vi^h oph-jiial cable Ctrioi (RGB) 
Video did MnnfKhrnmo iCcmnositn) Intotlnciw 
260 Processor bus interlace. 

TERMINAL MO DE: Allows the PC to operate as 
an ASCII terminal The terminal mode can Dc 
<!iiii:ri!ii Ircun it program or tvf the operator. 

Software omu'iiiois a*Wafflo lor most ibm and 

D|rxif m.unhamus. 




PERIPHERALS 

EXPANSION UNIT: Viuious Expanaton Units 
available (or. t loppy and/or Fined Disk. 
Memory Expansion, teal Trim Clocks with 
priority inioirupts: Single bit Input and Output 
porta. Addition Pi inter RS?32C, ana IEEE 468 
interfaces Card slots uraliabte lor user delined 
PCOs. 

DOT MATRIX PRINTER: r-aclor teed o. 
friction teed! ICO characteia'sec. bidirectional 
upper viewer ease cnaia<ters. numerals, symbols 
compressed, and double width character 
expansion true descenders; 3-1 D-cttar act c 
symbol set [maicnes POM clintiicier wit). 
Proportional spacing 

MASS STORAGE: Dual 525 or 8 inch floppy 
disk dines cpving flS5 K bytes Df ?.!> Mbytm st Or SQC 
capacity Comis Wintoesier disks at 6 11 or 20 
Mbytes available- MuiSplpigrj gpow sharing c< 5,?! 
men or Corviis otsk units between several 
much incs 

DISPLAY: M igh flosoliit.on 1? " Green Pnosphoi 
htgh ftesolution (2000 piiol) Color Display 

OTHER: Light Pens. CM Bod Plotters and otlwti 
peripherals available 



PROGRAMMING 

ENVIRONMENT 

DOS: NEC DCS 01 (optional) CP/M-. UCSD 
p" system. Hacer DOS elc. 

LANGUAGES: f-BA5IG 1 M . ■ , and 
■Asscrnotcrc-f (optional) Fortran. Cobol. PL/Z 
Pasoai, Lip. Basic Compilers. 

AVAILABLE SOFTWARE: N in* roi . 1 „ <ng« 
.avaitaejto immediately including Ben chniark* 
System Word Processor, Mailing !.■$■ Manager 
Various Accounting Packages including tiZ 
iequii(."nii*nis. Fanning PacKiicjos. Super-Calc". 

i«wi Ma«et". t /Mater" <?ic electronic 

spread~Srhcel«. Bur.iiess Planning Prick agis 
Database Systems- Telecommunication 
Pioiucols. Eew wariai Pnelragos 

NEC 

Nippon Electric Co Ltd 
Tokyo Japan 



COMPLETE LIST OF DEALERS ON FACING PAGE. 

OQSrnKlTERS 
C* Dmnn ol <*m Scwuy a Con«any LWJ 

4th Float. DFC Bldg. Cm Gr«y & FesltietatOA Sis, Wellington. P.O. Box 2377. 



FOR FURTHER DETAILS 
CONTACT YOUR NEAREST 
DEALER 

Aztec Management Services 
29-33 College Hill 
PO Box 47-182 
AUCKLAND 

Phone: IM) 793-496 

D E 8 J Goldllnch Lid 
Highbury HoitSG 
65-67 Birkenhead Ave 
PO Box 34-196 
AUCKLAND 10 

Phone (09) 483-342 

Software Architects Ltd 
10 Heather Street. Patnell 
PO Box 9652. Newmarket 
AUCKLAND 
Phone. (09) 732-427 

A1 Computer Services Lid 

Kings Arcade. Victoria St 

PO Box 1188 

HAMILTON 

Phone: (071) 193-000 

Waikato Computer Centre 

6 Princes Street 

PO Box 1094 

HAMILTON 

Phone: (071) 393-416 

Tsranakl Micro Electronics Ltd 

Centre Courr Budding 
Devon Street East 
NEW PLYMOUTH 
Phone: (067) 04-067 
Pattersons Office Systems 
211 Queen Street East 
PO Box 979 
HASTINGS 
Phone: (070) 85-161 

David Brice Electronics Ltd 
47 Kimbolton Road 
FEILDING 
Phone: (063) 37-141 

Hands On information Systems 
35-37 Vrclorifl Street 

WELLINGTON 
Phone: (04) 725-224 

Computers for People 

35 Taranaki Street 

WELLINGTON 

Phone: (04) 847-668 

Mainland Computers 

LeinsterHoLis* 
158 Lemster Road 

Me rivals 
CHRISTCHURCH 

Phone: (03) 554-339 
Intodala Systems 
Sixth Floor, BNZ House 
Cathedral Square 
CHRISTCHURCH 
Phone (03) 796-480 

Ken France Electronics Ltd 
40 Tatbet Street 
PO Box 213 
ALEXANDRA 
Phone. (0294)8021 

Generation Associates Ltd 

320 Princes Street 

PO Box 508 

DUNEDIN 

Phone- (024) 770-126 



BITS 6 BYTES. 



Hardware Reviews: 

The largest selling personal 
computers in Japan and USA 
arrive in New Zealand ... and 
we review them this month. 
Chris 0'Donoghue gets his hands 
on the IBM PC (Page 5) and 
Shayne Doyle runs over the NEC 
PC8000 (Page 8). 
System 80 owners yearning for a 
disk drive will be interested in 
Jay Mann's review of a New 
Zealand developed drive for the 
System 80 (Page 10). 

Sord arrives: 

We add a new dimension to our 
regular machine columns — 
Peter Hyde updates the Pips HI 
memory file, the latest release 
from SORD'S personal 
information processing system. 

Page 30 
Competition: 

Here's a chance for Sinclair users 
to "balance" Ecuation, the 
program which won our first 
competition. Wsyne Dobson, of 
Karamu High Srhnnl. in 
Hastings, supplies the details. 

Page 33 

Software Reviews: 

Our team of rev ewers starts a 
series of regular software reviews 
by looking at Multipioy (Apple 
arithmetic) and VIC-20 games. 

Page 1 1 
Education: 

Nick Smythe dismantles the 
mechanics of microcomputer 
networking systems. 

Pages 20-21 
Farming: 

Chris McLeotf asks why should 
farmers use computers, and 
explains how and where they can 
get access to them. 

Pages 17-18 
Books: 

Tony Lewis reviews a new 
Sinclair book and Gerrtt Bahlman 
&ets into computer language. 

Page 29 
Machine columns: 

An A-Mazing game for Atari 
users. 



Page 22 

A graphic game for the VIC. 
Page 24 

TRS8G/Systerns 80 columnist 
Gordon Findlay learns how to live 
with accidents. 

Page 27 

A tip for apple users 
Page 35 

BBC columnist Pip Forer works 
on benchmarks. 

Page 37 

Business: 

John Vargo gets down to the 
final selection of a system 
supplier and outlines what should 
be in the contract- Next month, 
he will discuss implementation of 

a new system. 
Micro News: 

IBM reacts quickly to critiscism 
and drops its prices for the new 
IBM PC. This and more . . . 

Pages 3,4,39 

Graphics: 

Pip Forer concludes his series on 
graphics by leading you up the 
"clip-on path" to better 
graphics. 

Pages 14-16 
Beginners: 

Gordon Findlay straightens out 
loops in hrs series on BASIC. 

Page 31 

Sorry 

Solicitors and architects stories 
have been caught up in the 
production cogs and have been 
delayed. They will be coming up 
in future issues. 

PLUS: 

Classifieds 38 

Club News 39 

Editorial 2 

Glossary 40 

Letters 12 



Post your 
subscription 

today 



€DITORinL 

Bits and pieces 

After six issues (you are reading the seventh) it is 
time to answer some queries (and dare we say com- 
plaints) from readers about the way we have done 
things. 

First off, the packaging of the magazine. That 
changed last month with a switch to plastic bags 
which we hope Improved the condition the magazine 
arrived in (no more ironing out the creases). 

Second, back copies. We ask for patience with 
these. The demand was such that our copies of issue 
number 2 disappeared quickly. Because of that de- 
mand a special reprint (minus the covers) of 500 
copies of issues 1 and 2 was done and most people 
should now have the back copies requested (sorry 
about the cover but the cost woutd have been too 
great). This is the last time a reprint will be done so if 
you want either of these two issues please hurry with 
your orders. 



We also request new subscribers to be patient. It is 
too time consuming to process subscriptions in- 
dividually as they arrive and recent demand ha? been 
such that our computer has been kept very busy. So 
all subscriptions start the month after they are receiv- 
ed and if you wish back copies please use the order 
form provided. 

Reader contributions. Keep sending them in but 
please don't expect them to be printed the next 
month. If you article or program is not acceptable we 
will return it otherwise we intend to publish it but that 
might not occur for several months so keep looking. 

Believe it or not we've also had complaints from 
some readers that the magazine's price is too low. 

Reluctantly economics says we have to agree and the 
price will increase when the price frown ends. So If 
you are not subscribing be in now. 



Coming up in 
BITS & BYTES 

Business Computing 

The Calc-a-likes — just what are 
financial modelling, programs and 
how can they help your business. 

The first in a series by Pecer 
Brawn which will include a look St 
the popular programs such as 
Visicalc. 

NZ business software. John 

Vargo reviews Auckland based In- 
ternational Applications Ltd 
"Charter" suite of business pro- 
grams. Case study of a small 
Business using a rnioxjconnputer 
for accounting applcattons. 

Hardware Review 

A new release from National 
Panasonic of Japan — the low 
priced JR1 00. 

Alternative machine code 
programming — John Durham 
puts the case for using machine 

code monitors. 



Plus columns an: 
Farming 
Education 
Beginners 



BITS & 8YTES is published monthly, except January, by Weill Sirss. 
Dion Crooks and Paul Crooks. Editorial and subscriber inquiries to 
Post Office Box 827. Christchurch. 

ADVERTISING: 

Auckland - Wandy Whitehead. Phone 794-807 
Wellington - Annie Carrad: Phone 723-431 

South Island - Graham Beecroft: Phone 554-265 Chch or telephone 
Christchurch 66-566 

EDITORIAL: 

Auckland - Cathy and Setwyn Arrow: 30A Bracken Ave. Takapuna 

Christchurch - P.O. Box 827 or Phone 66-566 

Wellington - Shayne Doyle. 280-333 ext 892 ,W). 278-545 IH) 

Production: Rofltc Browning. Graeme Patterson. LeeTeck Fgi, Janlno Worrell 

Typesetting: Focal Point 

Cover and Graphics: Sally Williams 

Technical Editor: Chi«s O'Donoghue 

Subscription rato: SH a year (11 issues! adults 
$6 a year lor school pupils 
Subscriptions begin from the next issue ol BITS & BVTES oflo« (nit subscription is 
received. 

Back copies are available (except issue* II at 91 per copy plus 50c por copy postage 
end packaging. 

Subscription eddressas: 

When sending in su bsct i prions pfease include postal crones 'or the cities. II your label 
is incorrectly addressed please send it to us with the correction marked. 

Distribution inQulries: Bookshops — Gordon aid Gotch, Lid. Computer stores — direct 

to the publishers. 

Printed in Christchurch by D.M. Adams. Ltd, 

COPYRIGHT: All articles ana programs printed in this magazine a»C copyright. They 
should not be sold 0' passed on to non- subscribers in any form: printed, or in tape or 
disk foimat, 

LIABILITY: Although -nnerial used in SITS & 8VTES is Checked lor Accuracy, no lability 
can be assumed for any losses due to The use of any material tn this magazine. 



mention BITS & BYTES when contacting advertisers 



MICRO N€UJS 

IBM has reacted quickly to 
criticism and lowered the prices 
tor the recently announced I8M 
PC. 

The price for what IBM sees for 
a typical business configuration — 
128K RAM. two 320JC diskettes. 
keyboard, screen, and a dot 
matrix printer — has been cut 
from $10,932 to S9860, a 
reduction of 1 1 per cent. 

As well this is post-devaluation 
i.e. the recent devaluation won't 
affect the price, meaning an 
effective reduction of some 20 per 
cent. 

And those people who have 
already bought IBM PCs won't be 
disadvantaged. The price 

reduction has been backdated to 
the release of the PC in New 
Zealand. 

IBM has also announced the 
release of 10 and 20 megabyte 
hard disks. The sample business 
configuration with a 10 megabyte 
disk replacing one diskette will 
cost S14.6O0. 

* * * * 



A direct competitor for the 
Apple II is now in use in at least 
one New Zealand school and is 
expected to be on retail sale here 
soon. 

Selwyn College, in Auckland, 
has purchased 1 5 Franklin Ace 
1000s, a "99.9 pej cent Appie 
compatible computer", according 
to the International Sales Manager 
for Franklin, Mr G.R. Treseder, 
who visited Nyw Zealand last 
month. 

Now the Educational Trading 
Society is offering the Ace 1000 
at $1850 ($1890 with colour) 
which is believed to undercut the 
education price for the new Apple 

He. 



Nevertheless it does have a 
numeric keypad. 15 Visicalc keys 
and a built-in fan. It will be 
interesting to see if a price 
differential occurs on the retail 

Apple Computer, Inc, has 
already lost a copyright suit 
against the Franklin Computer 
Corporation in the United States. 

"It is not a copy, it is a record 
player that plays Apple music," 
said Mr Treseder. 

Some of the Ace 1000s 
advantages over the Apple II, such 
as 64K RAM and upper and lower 
case characters, have 

disappeared with the release of 
the Apple He. 



COMPUTER OWNERS 

WE WILL MARKET YOUR SOFTWARE JN N.Z.. AUSTRALIA AND THE U.S.A 
ANY ORIGINAL APPLICATION OR GAMES PROGRAM WILL BE 

CONSIDERED. 

FOR FURTHER INFORMATION WRITE TO: 

THE REMAP KABLE SOFTWARE COMPANY LIMITED. 

P.O. BOX 9535. HAMILTON. N.Z. 



How to buy a computer 
by the numbers. 



Introducing Ihe Cromemco C-1 

Personal Computer. Under $5000, 
Including software, and you get 
more professional features and 
performance for the price than wilh 
any other personal compu ter on the 
-market. We've got the numbers to 
prove it. 

The C- 1 starts with a high- 
fesolution 1 2" CRT that displays 25 
lines with a full 80 characters on 
each line. Inside is a high-speed 2- 
80A microprocessor and 64K bytes 
of on-board memory. Then there's a 
detached, easy-to-use keyboard 
and a 5W " dfcsk drive with an 
exceptionally large 39QK capacity. 
That's the C- 1 0. and you won't find 
another ready-to- use personal 
computer that offers you more. 

But hardware can't work 
alone. That's why every C-1 
includes software — word 
processing, financial spread sheet. 
investment planning and BASIC. 
Hard-working. CP/M --based 
software that meets your everyday 



needs. Software that could cost 
ovei- S2000 somewhere else. FREE 
with the C- 1 The'e"s really nothing 
else to buy. 

Bui the C- 1 C's numbers tell 
only part of the story. What they 
don't say is that Cromemco is 
already known for some of (ha 
most reliable business and 
scientific computers in the 
industry . And now tor the 
first time, this techic-iogy 
is available in a personal 
computer. 

Z—80A 

64K RAM 

390K DISK DRIVE 

12" CRT 

COMPLETE SOFTWARE 

$4495 

Cromemco 




Cromemco 

Tomorrow's computers today 

MCLEAN 

INFORMATION TECHNOLOGY 



WCKUUO 

*0 Bfti H*i M-m»ttf< 






MICRO N€UJS 

miH KM » M MM» M »a ™ r 

From previous page 

Review of Franklin Ace 1000 
soon. 

* * * * 

The Auckland branch of the 
New Zealand Computer Society is 
to hold a seminar "Micro- 
computers for the Layperson" 
from 9.30am to 3.30pm on 
Saturday 23rd April at the 
Architectural Conference Centre, 
Auckland University. $2 

admission will cover lectures, 
videos, and discussions. Also on 
display will be a selection of books 
and computers- 

For details contact Ian Mitchell 
on 583-350. 

* * * * 

The B.B.C. computer-literacy 
project in the United Kingdom has 
not stopped at the end of "The 
Computer Programme" series. 

A second series is now on the 
air in Britain called "Making the 
Most of the Micro" and more are 



planned. 

A proposed future development 
is to transmit computer programs 
from the television studio to the 
B.B.C. Microcomputer fn the 
home using spare capacity in the 
television signal (similar to 
Teletext transmissions). 
¥ ¥ + ¥ 

Wrightson NMA intends 
setting up small computer bureau 
operations at its branches, using 
Sord microcomputers. Farmers 
will be given access to typical 
financial applications — cash- 
flow projections, account 
analysis, the ecoromics of farm 
purchase and anaysts of longer- 
term developments. 

* * * * 

Kellogg farm management 
courses on the use of on-farm 
computers are stil running. 
Workshops are planned for May, 
July and November. For further 
information, contact Mr J. 
Callan. Rural Development and 
Extension Centre, Lincoln 
College. Canterbury. 



Industry seminar 

The use of programmable 
manufacturing equipment to 
enhance the profitability of small- 
batch production will be the sub- 
ject Of a two end a half day 
seminar in Palmerston North on 

May 23-25. 

The seminar will address itself 
to- equipment that "works for 
you" — cutting metal, producing 
drawings, handling components 

Topics to be covered will in- 
clude computer-aided design, 
computer-aided programming for 
N.C. machines; C.N.C. and N.C. 
machines: flexible automation, 
and robotics. The main speaker on 
robotics will be Dr Alex Holzer, an 
Australian research scientist. 

Speakers from Cable-Price 
Engineering and Walker Scientific 
{representing Computer Vision) 
will also contribute. 

Further information can be ob- 
tained from: the secretary. 
Department of Production 

Technology. Massey University, 
Palmerston North, 



* SYSTEM 80 * SYSTEM 80 * SYSTEM 80 * 
MEMORY EXPANSION AND DISK DRIVE 

DESCRIPTION: 

1 . Memory expansion. The addi lion of 32K RAM is carried 
out by (he addition of a board within the computer, 
powered from the computer's power supply. Full 
buffering and heavy power supply filtering coupled *'iih-j 
the use of Prime spec, components and top quality 
I.C. sockets ensure reliable operation. 

2. Disk Drive Interface. This unit is housed in the case with 
Disk Drive and powered from the Disk Drive supply. All 
connections to Disk Drive arc permanent and internal. Edge 
Disk Drive connectors are provided foi connection to other 
Disk Drives, a Parallel Printer and the SYSTEM 80 expansion 
edge is repeated on the interface to allow the connection of other 
SYSTEM 80 peripherals. 

Six switches arc available on ihe front of the interface. 

PRICE $1495.00 complete with 40 track floppy drive, DOS, manual etc. 

Non standard versions subject to special quote 




Write to: 



Ph 62-894 

940A Colombo St. 



M44CL 



Box 21-024 
CHR1STCHURCH 



Ph: 555-699 

192PapanuiRd. 



(•ttaWMMOMdMUtf 



I II 1 1 1 II II llll II MlMimmilllH. 



HARDWARC R€VI€UU 

Hands on the IBM PC 

By Chris O'Donoghue and easy to follow. 




The machine as tested had two 
five and a quarter floppy disk 
drives, 64K of memory and a 
monochrome display/parallel 

printer interface with green on 
black monitor and an eighty 
character per second parallel 
printer. 

When turned on the IBM 
personal computer performs a self 
test of all system components. 
Documentation 

Documentation consisted of 
three manuals, a technical 
manual, a BASIC manual and a 
general information/DOS manual 
(although the technical manual is 
an extra). 

In general documentation was 
complete, easy to understand, 
with simple examples. But I did 
find some inconsistencies. For 
example, in the BASIC manual on 
the subject of conversion from 
single precision variables to 
integer variables, it stated that 

DASIC truncates cingl© precision 

variables to integer, later in the 
same section the manual stated 
that BASEC rounds single 
precision variables to integer (this 
is in fact what it does). 

The documentation comes 
nicely packaged in ring binders 
each with a case. All 
documentation is fully indexed 



Hardware 

The IBM PC is based on the Intel 
8088. a chip with an internal 16 
bit structure and an 8 bit data bus. 

Inside the system unit is 64K of 
RAM, 40K of ROM (used for boot, 
system check and BASIC) a 
cassette interface, and room for 
disk handlers. There is also a 
keyboard interface. 

Then comes the five expansion 
slots, I feel this is carrying the 
"simple system with user defined 
expansion" a b't too far. 

There should at least be a 
display interface included with the 
primitive system. Instead one of 
the five expanson slots was used 
for a monochrome display/parallel 
printer interface costing $699, 



leaving four slots to plug-in 
expansion boards. Of these there 
are options of up to two memory 
boards (giving expansion up to 
544K of RAM), a colour/graphics 
display board, various 

communications options. 
Keyboard/Display 

The keyboard has 83 keys, 
including 10 function key, 
numeric keypad, cursor 

movement and special keys such 
as a print screen key. 

An 8 bit character set is easily 
access able with the lower 7 bits 
giving the ASCII character set. 
The other 1 28 characters are 
graphics characters. 

The keyboard is connected to 
the system unit by a spiral cable 
and typing angle can be adjusted. 

This is a very good keyboard 
and it has a wonderful feel. 

The display is green phosphor 
with 25 lines by 80 characters 




WE DONT JUST SELL COMPUTERS... 

WE GIVE YOU ALL THE INFORMATION YOU NEED 

COMMODORE + ATARI + SINCLAIR 2X81 + SIRIUS + BBC + SYSTEM flO + WIZZARD 

Patrick Dunphy has over 1& years' computer programming experience and is now combining this with TV and 
video technology. He can talk io you in English about your computer requirements. We also have a large 
Stock of cheap colour TVs and monitors. 

Programs avoJfabfe include: 

i\\ Chess 

Galaxians 

Pilot 

Moon Lander 

Auckiands largast selection of programs, boots, games, programming courses, pane', all aece5sw.es., cassette*, cartridges, etc. 
Business systems also avatlabln. Mail Ofders and all credit curds accepted. Hire purcnaso available. 





SUFWKH BJECTRONICS 



430 MT EDEN POAD. MT EDEN 



TELEPHONE 605-216 



PO. BOX 26C0 AUCKLAND 



HHRDUJnR€ R€VI€UJ 



r ^^^' ^ i'»i' " Wt**"«'^'" -J -'~ J ' J, *^-^"' JJJ * WW ' a "^ Jj ™" 







„.,,,,. »n 



wide. 

Characters can be underlined, 
blinked, set in high intensity or 
reverse video. Full upper/lower 
case and graphics characters are 
displayed. Screen can also be set 
so that typed characters are not 
echoed (good for passwords etc). 

Disk: 

The disk drives are either 1 60K 
or 320K depending on how much 
money you have. They take 5%. 
inch floppy diskettes and are not 
too noisy. Up to 2 drives are 
supported. 

Software: 

There is a large software base 
available for the IBM. PC. These 
include operating systems such as 
CP/M-86 and UCSD p-system, 
compilers such as BASIC, 
PASCAL. FORTRAN and COBOL 
and a host of packages from 
VISICALC and MULTI-PLAN 
through EASY WRITER to the 
Business packages. Charter and 
Attache, and games. 

Operating System: 

The operating system PC-DOS 
will support one or two diskette 
drives. File structure is of the type 
DEVICE: FILENAME. EXTENSION 
where FILENAME is up to eight 
characters long and EXTENSION 
is up to three characters long. 

No attempt seems to have been 
made to include a hierarchical 
structure such as sub-directories. 

Apart from handling files the 
DOS does the other common 
things, displaying directories, 
renaming files, copying files etc. 
There is also a nice line based text 
editor called EDLIN which I found 
very useful in changing ASCII 
files. 



BASICS: 

BASIC on the IBM PC comes in 
a confusing four versions. 

1 . Cassette BASIC, included in 
ROM, is a full BASIC that 
handles cassette I/O, printer 
output. and light per 
functions. 

2. Disk BASIC, loaded from disk, 
it is a full superset of cassette 
BASIC. In addition it handles 
disk I/O, communications (if 
communications interface is 
present). It also has time and 
date functions. 

3. Advanced BASIC, is again a 
superset of Disk BASIC, but 



includes event trapping and 
colour/graphics function (if 
the colour/graphics board is 
present) - 
4. Compiler BASIC, an optional 
compiler for $709 (not 
tested). 
Of these four versions I tested 
the three interpreter BASICS, 
These are all upwards compatible 
i.e. anything written in cassette 
BASIC will run on Disk and 
Advanced BASICs etc, but not so 
the Compiler BASIC. 

I used the Advanced BASIC 
most of the tine to get the widest 
possible range of functions. The 
BASICs are written by Microsoft 
and Advanced BASIC is a superset 
of standard Microsoft BASIC. 

A nice feature was the event 
trapping which was available for 
function keys and communi- 
cations events (e.g. receiving 
data). This was of the form: 
ON event GOSUB n 
In the case of function key 
event, trapping was KEY<m) 



where m is in the range 1 to 10. 

Communications were also 
handled nicely. They were treated 
like a normal file i.e. after doing an 
OPEN "COM... statement 
normal PRINT f* and INPUT # is all 
that is needed. No INP(n) etc are 
needed ■(if you have the right 
Interface). 

Overall IBM seems to have 
made a reasonably conservative 
product. The BASIC is not overly 
structured, the DOS doesn't 
handle complex directory 
structures etc. But the lack of 
major faults in this computer is 
remarkable. However with the 
amount of software available and 
sure to be available soon this 
machine should take a large share 
of the market. 

This is despite the price tag 
(typical small business 

configuration around S 10,000) 
but is partly because of the label 
which seems to be perhaps the 
biggest selling point. 




icrocomputer 



Name: 

Manufacturer 

Processor; 

Clock Speed: 

RAM;. 

ROM: 

Input/Output: 



Keyboard: 

Display: 

Languages: 

Disk Operating? 

Systems: 
G rap files: 



Sou 
Cost: 




a Options: 



Peripherals; 



IBM Personal Computer 

IBM 

tntsl 8088: ; 

4 MHz 

64K-544K 

40K 

Two 5V« inch floppy disk drives, cassette interface, 

Centronics parallel printer port. Video. 5 expansion 

s"ots. 

83 key, auto repeat, numeric key-pad, edit 

10 programmable function keys. 

25, lines fey 80- characters, upper /lower case, 

tmdarlinmaj blinking, reverse videos grGenJstioaphor. 

Microsoft BASICs (see text} compilers for Pascal; 

BASIC, Cobol, Fortran. Macro-Assembler. 

PC-DOS, also CP;'M-8e ( UCSD, GP*M 80 sohcarii. 

Character level graphics on system tested. With 

additional Colours/Graphics board: 320 x 2< 

4 Colour, qr 640x200 ZlColouftJ 

Sound generator and speaker. 

System as tested approx $9,000. Additional: 

colour/graphics card «-- $658, Asynchronous 

Communications Card ~ §313- Tr^ese prices subject 

to price reduction announced late March. 

Many Hardware and Software options exist. 

Including : Inemq[y .expansion to 544K, SDtC 

communications. 

Printer, disks, other machines (e.g. laboratory 
machines} through communicartions adaptors. 



IT 



N HFRF' the IBM of 

o flciye.. Personal 

Computers 

For 40 years IBM lias built 
up a wealth of experience and 
expertise in computers. 
Now that knowledge is built 
into a tool for modern times: 
the IBM Personal Computer. 

As with any new tool, you'll want to get comfortable with 
the IBM Personal Computer before putting it to serious use. 
You'll have some stcp-by-step reading, but our instructional 
literature involves you from the start. And the Computer is on 
your side too — interacting with you as you learn. There's no 
reason why you can't be executing programs and feeling good 
with the results within your first week. After a month, it should 
be clear that you've made a good investment, and you'll 
probably be telling your friends why they should get one. 



To keep up with 
modern times, visit your 
authorised IBM Personal 
Computer dealer today - 
or call at the IBM Product 
Centre in Auckland, 
Wellington or 
Christchurch. 
Ask what programs are j 
available now. Get a 
demonstration. 
Be sure you check out the 
specifications and features 
that make this the IBM of 
Personal Computers — 
features that set it apart. 
You'll find that the quality, 
power — and readability 
— arc what you'd expect 
from IBM. The price isn't. 




HELPING PEOPLE FIND THE ANSWERS 



The IBM Personal Computer. 
A. tool for modern times. 



Whansareli MM Ibiiccm fid Co. Led Phon* 84-9"9 Auckland: B«« Shop Phone 52-860 Compmcrlxnd (NZ) Ud Phone 798-005 or 798- 
ll~8. Financial Svsicms Limited Phone "89-068 «r 789-069. International otitic E(|uipmcn< Phumc 775-57-2 Hamilton: Thomson & Ward 
( 19" I ) Lid. Phone 82-6" 1 ) Koto run- Thomson Ik VartI f I9~l > Ltd Plmnc *"'9-I - 2. Taurangai Hay of Plenty Office Supplies Phone 81-009 
Hastings: Midland Daia ProccH-inR Phone 84-528 F«Imer*ton North: Dado* Electronic* ltd Phone 70-845 or 70-849. Wellington! 
Compvwles Phone H44-H6 Pntijrci Computers Phone 731-152 Uardcom Bureau Phone "'29-028. Nelson: Geo Berry-man ti*l Phone 
8 1 -489 Ch rUtchurch: Small ii.miu« Software Lid. Phone 64-6 1 "or 64-71 ".Dunedlti: Whltcoulls Ltd. Phone 7~4-l2<> lnvcrcarglll: Office 
Cqulpmcm Southland Phone 8V-l4o. • IBM Prudutt Centres Auckland: Phone "'78-910, Wellington: I'hunr "29-199 Chrlwchurchi I'twnc 
"92-840. Suva, FIJI: Kcllon, .Marketing Ud Phvnr $85-53$ 



HARDUJAR€ R€VI€UJ 

NEC PC 8000 

"effective 
productivity 

tool 



#/ 



By Stiayne Doyle 



computers 

in schools. 



CPU/Keyboard 



One of the five 
recommended for use 
the NEC PC-8000 system loaned 
to me for this review was a CP/M 
colour business version 

comprising: 
•PC-8001B 
console 

• PC-801 1 B Memory expansion & 
Interface unit 

• PC-8031 B Dual floppy disk drive 

• PC-8023B Graphics printer 

• PC-8043B Hi-Res colour 
monitor. 

Price, around $8,600. 

Over the week or so that I had 
the machine, I grew to like it very 
much, parting with it reluctantly. I 
found it extremely easy to use, in 
fact, within the first two hours I 
had started writing this article us- 
ing the CP/M Word Procesor 
SELECT. 

Physically, the system is similar 
in size to most other business 
computers in it's class, but I was 
most impressed by the solid well 
engineered system components. 
The CPU/Keyboard unit is very 
definitely designed to withstand 
hard knocks and a lot of use, being 
a substantial metal enclosure. 
There is very little use of 
lightweight plastic anywhere in 
this computer system. 

Unpacking and connecting the 
system together took me a half 
hour and the only problem I had 
was with the cable between the 
disks and the expansion unit — 
these are edge connector types 
and if not pressed firmly home 
they can grip the edges of the cir- 
cuit board without mating proper- 
ly with the foil tracks. Apart from 
this, the whole system fired up 
and proceeded to load disk Basic 
as soon as it was switched on. 
Normally, however, this system 
would be installed for you by 

8 



TISCO under contract to Scollays. 

By stacking the disks, expan- 
sion unit, a-^d monitor behind the 
keyboard (remembering to 
preserve ventilation airflow 
space)! and sitting the printer 
alongside, a, very compact in- 
stallation can be achieved. This 
also situates the monitor at a com- 
fortable eye level. 

The do-it-yourself programmer 
will enjoy working with the NEC'S 
Basic screen editor — I found it 



very versatile, and it made writing 
code so much quicker than with a 
line editor. I also found I preferred 
using the 40 column screen 
width, with the consequent larger 
character size, when programm- 
ing. The display may be easily re- 
formatted with the WIDTH state- 
ment, and CONSOLE sets up other 
display feaures, 

The standard graphics facilities 
are not particularly impressive, 
with only 160 x 100 pixel resolu- 
tion, a LINE statement, and what 
are effectively SET and RESET 
statements. I did, however, have 
a disk of 12 machine code 



Microcomputer 



Name: 

Microprocessor 

Clock Speed: 

RAM; 

ROM: 

Input/Output: 



Keyboard: 

■' : ■ ■ ■ 

■ 

Display: 
^Unguages: 

Graphica: 

-■■ 

Sound: 
Cost; 

. : . ■ ■ 

■ . .:■ . : ' .' 

Options: 





DOS Options: 

" ■ ' . . . .■:■ : 

Peripherals: 




Features: 



.. .,- 



NECPC-8001 

U.PD780C-1 .(280A equivalent) ■ 

■4 Mtiz 

32 KBytes Dynamic ' 

24 K Bytes for Basic and macJiihe language 

Monitor 

Coiotfrand B&W video- 

600 baud FSK; cassette: ;■" 

Paraifei Printer interface 

1/0 Expansion Interface. 

Full ASCII with numeric keypad, 5 ahifted^ro- 

gramfnabln iiin'rtlon keys, olternaW* ehetaefer ■ 

set, graphics set from special graphics "shift" 

key. 

Format user definable — 20/25 lines per 

screen, 36/40/72/80 cheracters per Una, k -. 

NEC N-Busic, Z80 machine code \ assembler; 

Fortran. Cobol, PUZ, Pascal. Lisp, Basic 

Compiler. 

V28 graphics : characters, 160 x 100 pixel 
resolution, 8 colours, variable intensities. ■ | 
Built in speaker. 

(teste, unit cost — $2140 which includes 32K 
CPU keyboard console; and Green screen 
■monitor. 

3 different expansion units for memory expan- 
sion, adding floppy or hard disk drives/ 
p-8rs!ielteerial/lEEE488 I/O pons,, extra printer 
pons, priority interrupt real-time clock, slots ?P* 
user PCB's (printed circuit boards), tight pans. 
Voice recognition units. Flat Bed Plotters, Hi- 
Res graphics (640 x 200 .pixels*. 
NEC .DOS, CP/M, UC;Sp p-system, 
DOS; 
PC-8043 Hi-Res Colour Monitor 

Medium Res Colour Mojnitor 
PC-8023 Dot Matrix "printef 
PC-801 1 Expansion Unit ' ' 

Minimum cMsK interface 
PC-8031 Dual mini disk drive 
CORVUS Hard Disk Drives up to 20 Bytes, 
Terminal Mode =■ — allows the computed to 
operate as a standard terminal with emulator 
software for most IBM and ether mainframes. 



StOSO 
5470 

SI 440 

ii&w 

$250 
$2340 



HflRDU)flfl€ R€VI€W 



graphics games, which 

demonstrated that quite effective 
dynamic displays can be 
achieved!. 

The LINE statement has 
parameters which control colours 
or, if black and white mode, video 
attributes such as reverse, blink- 
ing, secret, and combinations of 
these. The graphics and alter- 
native special character 
sets, while residing in the usual 
decimal 128-255 positions;, can 
also be entered directly by a 
special graphics shift key, and 
alternative character set shift key. 

Extensive print formatting 
facilities using "mask" techni- 
ques are available, and the same 
formatting is used for writing 
basic sequential disk file records. 
Both sequential and random ac- 
cess disk files are handled under 
NEC DOS Basic, and it is quite 
literally "child's play" using the 
disk features. 

A very extensive repertoire of 
functions is offered, more than is 
usual, with quite a few devoted to 
conversion between the various 
variable types. There are func- 
tions tn convert between decimal, 
octal, and hexadecimal, and in 
fact, the latter two bases may be 
used directly by using special 
prefixes to the numbers. 

Both date and time functions in- 
terrogate the computer's internal 
clock. Programmers used to 
TRS-80 or System 80 will be glad 
to see the very useful VA.RPTR 
variable pointer function. 

For the "die-hard" hex machine 
code programmer, a basic 
machine language monitor is pro- 
vided, offering eight commands — 
display and alter memory, load 
and write tape, verify tape, go to 
address, test memory, and return 
to Basic. 

Moving away from DIY soft- 
ware, adding the RACET disk 

operating system ($2501, allows 
the use of keyed files, sort 
utilities, etc. A Spreadsheet pro- 
gram ($104>, and a Word Pro- 
cessor ($130) are available. 

Expanding to a full CP/M Disk 
Operating System ($200), gives 
access to the vast range of ap- 
plications software written for 
CP/M computers. These include 
accounting systems (PADMEDE. 
IAL, GOLDFINCH etc). Budgeting 




* ". ; — 




and Planning programs (Report 

Manager, Supercalc, Scratchpad, 

T/Maker etcl. Database manage- 
ment software (DBASE II, 
FMS-80, CONDOR etc). Word 
Processor programs (SELECT, 
BENCHMARK, WORDSTAR etc). 

For more sophisticated custom 
written programs, a choice of 
language compilers - Basic, 
Pascal, Cobol, etc. 

Documentation was very well 
covered, a comprehensive manual 
being provided with each compo- 
nent of the system, NEC Basic 
reference marual and quick 
reference programmers card. The 
applications programs had their 
own detailed manuals. 

The quality of the manuals is ex- 
cellent, and the only adverse com- 
ment I would make is on the lack 
of a detailed index in the back of 
the manuals, although there is a 
table of contenis at the front of 
each. 

Apart from this small point, I 
could only really criticise this com- 
puter on three counts. 

Firstly, the prhter is rather noisy 
in use and would benefit from ad- 
ditional sound proofing. It also 
emitted an *nnoying whistle 
(about 9-12 Kh2) when turned on. 



Enquiries established that this 

peculiarity only appears in printers 
manufactured up to a certain 
serial number. While this printer is 
bidirectional, it was tedious to find 
that SELECT does not take advan- 
tage of this, and only output print 
in one direction. 

My second gripe is minor, and 
reflects the basic nature of the 
standard graphics facilities. There 
appears to be a limit to the number 
of pixels that can be SET at any 
time, and I also felt that some 
form of programmable character 
generator should have been 
available, not to mention some 
sort of "sprite" system. 

The third point is of interest to 
the computer hobbyist — this 
machine does not have a parallel 
or serial port on the basic console, 
these are in the expansion units. 

The business user will not, 
however, bother about these lat- 
ter two criticisms, and in my opi- 
nion could consider this computer 
a very cost effective productivity 
tool. As you may gather, my 
overall reaction is definitely 
favourable, and I enjoyed working 
with the NEC PC-8000 computer 
system. 



& 



HRRDUUflR€ R€V1€UJ 



A clever disk-drive expansion 
for the System-80 b y jayd. mann 



Until now, System-80 owners 
wishing to expand their 
computers have had to purchase 
one or more adapter boxes to be 
added via the expansion 
connector at the back of their 
keyboard unit. They can now 
purchase a pair of locally made 
units that provide expansion to full 
memory plus disk and printer 
operation in an elegant fashion. 

There are two parts to the 

expansion. First 48K of RAM is 
installed inside the System-80 
keyboard box. Second, a 
combined disk drive/disk 

controller box is plugged into the 
expansion connector in the back, 
of the System-80. (You could use 
a disk drive without any memory 
expansion, as I did briefly for this 
review, but the software involved 
in controlling disk operations is so 
bulky that there won't be enough 
room in your memory for many- 
useful programs.) 

The in-keyboard expansion is 
done by thn nVvplnppn;. Mir.ro 
Processor Services of 

Christchurch, or by one of their 
agents. This step should not put 
you off, for it is an excellent way 
to expand memory. They have 
local agents throughout the 
country. Alternatively, you could 
mail them either one board from 
your System-80, or the entire 
computer. If an external 

expansion interface is used, it 
contains a great deal of circuitry 
that duplicates logic, buffering, 
and timing circuitry already 
present inside the keyboard unit. 
By using the in-keyboard memory 
expansion, there is no need to 
duplicate these circuits. You have 
a computer that has a full 
complement of memory without 
any expansion board, adapters, 
and extra cables. 

In addition, if you install a ciock 
speed-up modification, the in- 
keyboard memory has no trouble 
keeping up with the increased 
throughput, whereas many 
expansion interfaces have internal 
timing circuits rigidly locked to the 
standard System-80/TRS-80 

clock. Such expansion units 
cannot work properly with 

10 



computers wording at speeds. 

Wait a momant. you must be 
saying. What about the other 
functions of an expansion 
interface, such as a disk drive 
controller and a parallel printer 
port? The gooc news is that the 
folks at Micro Processor Services. 
Ltd, have come up with a 
compact, well-designed expan- 
sion boa rd that is built di rectly into 
the base of yojr first disk drive, 
No additional boxes or cabinets 
are needed. A single 50-pin 
parallel cable connects the 
System-80 to the disk 
drive/controller. The unit provides 
standard parallel cable connectors 
for additonal drives, a printer, and 
further use of the System-80 bus. 
Think of it. A single cable between 
your computer keyboard and the 
disk drive, and you have a 
complete system that is still highly 
portable. 

The expansion board is not a 
bare-bones design but instead 
provides a nnmhpr nf refinements 
not available on expansion boards 
designed overseas. These are 
controlled by a row of toggle 
switches set underneath the disk- 
drive door. 

The most useful addition is the 
ability to fool 1he computer into 
thinking that a printer is attached 
when it is not. This can be very 

important for programs that 
normally LPRINT at some point. If 
you have just spent a long session 
entering data, and then the 
program jumps to an LPRINT 
statement, normal System-80 
computers will lock up unless a 

printer is actually plugged in. 
Pressing the Break key won't help; 
you have to push the Reset 
button, and lose all you data. The 
Printer Disable switch bypasses 
the LPRINTing. Your results won't 
be printed (obviously, if you've no 
printer!), but at least the program 
will continue to run. You could, of 
course, edit the entire program to 
change LPRINT to PRINT 
everywhere, btt one slip-up and 
all is lost. fSorre but not all disk- 
operating systems let you route 
printer output back to the screen. 
Again, this wsrks well if you 



remember to do so before and not 
after the computer gets hung up.) 

If you do have a printer, then 
the expansion unit provides a very 
well designed parallel printer port. 
Not only does it respond in the 
System-80 "OUT FD" instruction 
but also to the TRS-80 "LD 
(37E8), A" instruction as well. No 
switches need be thrown. This 
overcomes one of the major 
difficulties with the "improved" 
System-80 software using a 
proper Z80 "OUT" 

instruction . . it is incompatible 
with a large amount of TRS-80 
software that tries to use the 
37E8 approach. 

All would be well if all printer 
commands went through the ROM 
routines, but because the ROM 
routines are rather minimal many 
advanced programs are designed 
to control the printer directly. 
Thus, the New Zealand-designed 
board solves the problem neatly 
by responding equally well to 
System-80 and to TftS-8:0 printer 
commands- 

Two separate reset switches 
are provided. One is like the 
normal reset button on the back of 
the computer. The other one acts 
like a power-off reset. A 
particularly useful switch allows 
you to fool the computer into 
thinking it is a non-disk system. 
An annoying aspect of disk- 
expanded System-80 and TRS-80 
computers is that hitting the Reset 
button fills the screen with 
garbage while the computer waits 
for the operating system to be 
loaded off the disk — even if you 
don't have a disk in the drive or 
are operating without a drive 
connected. 

A Write-Protect switch blocks 
transfer of data to a disk, so that 
you can do certain risky 
operations without putting 
garbage on your disk. 

Finally, room has been left for 
future addition of a double-density 
controller to the system. A switch 
will then determine whether the 
system boots up in single or in 
double density. The System-80 
normally starts up in single- 
density. If suitable hardware is 
present, it can then be switched 
to double-density. 

On examination of the interior, 
the disk controller unit can be 
seen to consist of a separate 



power supply plus two well- 
planned double-sided printed 
circuit boards, with plenty of room 
and no likelihood of heat build-up. 
The two boards are stacked one 
above the other, and fitted below 
the MPI disk drive. The boards are 
linked to each other by a 20-pin 
plug-end-socket connector that 
provides some of the mechanical 
support for the upper board, and 
will simplify any necessary 
servicing. A flat cable leads 
upwards internally into the 
attached disk drive unit, which 
has its own independent power 
supply. Typical of the thought that 
has gone into this unit is the 
mounting of the U-shaped disk- 
drive cover. In addition lo the 
customary four screws, there is 
a'n additional pair of screws that 
serve as hinges so that the cover 
can be swung up out of the way. 
{For those who may be 
confused about terminology, a 
disk is the 5-inch flat object that 
spins around inside a disk drive. 
The disk drive itself is pretty 
unintelligent, so the job of getting 
information on and off the disk in a 
form m«nningfnl to the- computer 
is done by the disk controller. 

You may have gathered that I'm 
enthusiastic about this system. I 
am. My present configuration is a 
System-80 with a separate 50/40 
adapter that in turn leads to an 
LNW expansion board in its own 
big case. From this, one cable 
snakes out to the disk drive and 
another to the printer. When I tried 
out the MPS configuration, with 
the combined disk drive/controller 
box sitting on my table next to my 
keyboard unit, the extra desk 
space and lack of clutter was 
most impressive. The operation of 
the controller was, as it should be, 
unobtrusive. Single-density disks 
booted reliably and the printer 
responded to LPRINT and LUST 
commands. When i disconnected 
the printer and threw the Printer- 
Deselect switch, I was able to run 
programs that called for LPRINTs 
without the computer locking up. 

This combination of in-keyboard 
memory expansion plus a disk 
controller built right into the first 
disk drive, is not available 
anywhere else in the world. It 
should have a market not only in 
New Zealand but overseas. 



SOFTUJAR6 

*MMMMSNMMMMOMMMMIMMMMM 

Learning in 
space 

Apple Software for schools: 
Multiploy. Availeble for Apple II 
48K on disk. Retail $36.95. 
Reviewed by Kathy Broadley. 

The microcomputer as an 
educational tool has not been ex- 
ploited yet in New Zealand. Few 
primary schools have even one 
micro, so the use of this potential- 
ly useful teaching aid is just a 
gleam in the eye of some teacher 
enthusiasts and some hopeful 
parents. Perhaps this is just as 
well since many of the so-called 
educational packages are 
technically competent but educa- 
tionally doubtful. The objective of 
getting the user to practise 
number facts can be achieved 
with 3 spirit duplicator worksheet 
for a fraction of ne cost of a com- 
puter program, even though the 
immediate reinforcement of 
knowing whether the answers are 
correct is probably handled best 
by the computer 

Decause I have seen some poor 
packages I was somewhat scep- 
tical when I loaded "Multiploy", 
by Paul Coletta (Reston Software, 
Prentice- Ha II, distributed in New 
Zealand by Whitehall Books). With 
this package I was pleasantly sur- 
prised. The accompanying booklet 
claims that "Multiploy" "com- 
bines the excitement of an arcade 
game with the cnallenge of learn- 
ing and practising arithmetic 
skills." The target age range is 
four to 14 years, "but adults like 
it, too". There are three levels of 
difficulty and the user chooses 
from the four arithmetic opera- 
tions. Within each level the speed 
at which the problems must be 
answered can be manipulated. A 
nice feature for classroom use is 
the option of low-level sound. 



The arcade game aspect is 
catered for in the way each pro- 
blem is presented. Each problem 
appears in a smiling (sp-ace)ship. If 
the correct answer is entered the 
ship is shot down. If the problem 
ship is not destroyed, it will even- 
tually start shooting back, 
possibly destroying the user's 
answer 'base'. Up to four pro- 
blems are on the screen at once, 
descending towards the 'base'. 
The user is given a rank that is 
determined by the number of cor- 
rect responses. A perfect score at 
any level attains the rank 
Multiploy. 

For classroom use a recordkeep- 
ing feature would have enhanced 
the program's value. A record of 
problems incorrectly answered by 
each user could be of assistance 
to a teacher making decisions 
about what should be taught next. 
Equally useful would be an 
authorising system so a teacher 
could insert his/her own problems. 
Perhaps future revisions of 
"Multiploy" might include these 
features. I also wondered whether 
more traditionally-known ranks 
such as Lieutenant or Admiral 
might be more attractive to 
children. 

The instruction booklet is clear 
enough for a fairly amateur 
operator to handle. That's impor- 
tant since most teachers will fall 
into that category until micros are 
more commonly used in schools. 
More information on the scope of 
the problems included at each 
level would be useful. 

This arithmetic practice pro- 
gram uses educational aspects of 
the microcomputer intelligently. 
The motivation of the arcade 
game format is harnessed. It is a 
drill and practice package, not a 
teaching one. As a drill and prac- 
tice package it is more imaginative 
and lively than most, and would 
be useful at all levels of the 



MULTIPIjOY 



(Apple Arithmetic Software) by Paul Coletta $36.95 N.Z. 

Preniice-Hall Inc Publication 

While first and foremost a novel Educational drill tool. MULTIPLOY. U so much fun to 

play thatyoushouldn'tbesurprlsedlili starts attracting people a way from video arcades. 

Available a t all leading Booksellers, Computer Stores and through 
BITS & BYTES Computer Book Clab. 

Ditf, WHITEHALL BOOKS. 



11 



SOFTUmRC 

primary or intermediate school. 
The harshest critics are the con- 
sumers, so I tried "Multiploy" on 
my two 13-year-olds and 10 and 
nine-year-old friends. It emerged 
with flying colours. 



Games for 
the VIC 



VlC-20 Games. Topes 1 and 2 
James Electronics Ltd, Box 527, 
Thames. $15 each. Reviewed by 
AJ. Petre 

With three good games a tape, 
the James tapes are good value. 
They also make excellent use of 
graphics and of colour — too 
many programs these days have 
badly-chosen colours that do not 
contrast. The result is illegible 
lettering and invisible games 
symbols. 

TAPE 1 has "Snako" "Maths 
Game", and "Ball in Bucket". 
The first two need memory 
expansion which should be 
ehown more obviously on the 
packaging. "Snake" is similar to 
the caterpillar-style of game - 
your snake (which will screen- 
wrap) gets longer as it gobbles 
mice. After a certain time mice 
turn into gravestones, and if your 
snake bites them, or itself, it 
dies. Good sound, quite 
addictive. 



"Maths sets the task of 
making mathematical expressions 
of varying difficult equate to an 
object number — a timed game 
against the VIC. Good stuff for 
making maths fun tor the kids, 
and hard enough in its upper 
skill-rates to keep even the 
whizz-kids guessing. A good 
mind stretcher. 

"Ball in Bucket" is a simple 
but good-fun dexte'ity game, in 
which the player uses specific 
symbols to bounce a ball into 
containers. 

TAPE 2 needs no expansion, 
and has "Formula 1", 
"Concentration," and "Line 
Game". Two of these are for 
two players — something we 
need more of in computer 
games. 

"Formula 1 " is a fairly typical 
race game, with good graphics 
and colour, but only average 
sound. You have to get around 
the track without running or 
spinning off, wearing out brakes 
and tyres. The car is hard to see 
at times which leads to 
frustration and crashes. That 
apart, quite a good axample of 
its type, but less gripping than 
some. 

"Concentration" s simple, but 
addictive. Two players seek 
mystery symbols under the 
letters on the screen, the aim 
being to pair them up. It needs a 
good player memory and good 
attention — with good colour 
and graphics, it's a winner. 




SEND ME FOR MORE INFORMATION 
OR TO ORDER: 

Check-Point Computers Ltd 
Private Bag, Tawa, Wellington 
Phone: 326-999 



1 8 K Microbes 


S329 


Rotail 


32 K Microtoee 


$990 


Petaii 


64 K Microtoee 


SI 350 


Retail 


Single disk drive 


Si 509 


Retail 


G*e?n screen tncoiiors 






Synao 


$299 


Retail 


Zenith 


$349 


Retail 


Sanyo 


$388 


Retail 


Education prices on application 





information 


LI 


Order 


U 




I I 


Prmieis 


□ 


Screens 


Li 


Irak Drives 


D 


Disks 


II 


Sofuvare 


LI 



r«A« 



ADOKSS 



PW.V-" 



"Line Game" is a simplified 
version of the "Snake" or 
caterpillar game — steer two 
lines (one player each) into or 
away from collision. Simple but 
fun. 

One point: "Formula 1" and 
"Concentration)" have good 
written instructions on the 
leaflet, but none in the program. 
A bad idea, I think. We all -end up 
losing those little bits of paper. 
then it's hell working out which 
keys to use. 

My rating for both tapes: 

Loading and instructions: 

Good. 

Colour and graphics: 

Very good 

Value: Very good. 

Player interest: Good to high. 

A final point: these are streets 
ahead of many imported 
games. . . bet they'd sell 
elsewhere. Governments, please 
note. 



l€TT€RS 



Taxing the 
computer 

Sirs — Many thanks for a very 
informative article on duty and 
sales tax on software etc 
(February '83 issue). As I write 
this, I still await an answer to an 
enquiry from the custom house in 
Wellington. Perhaps, the com- 
puter they use can' t or is st ill corn- 
put ing the variety of tariffs 
available to the department. 

It is a pity I didrVt receive this 
issue until the day of "media for 
data processing equipment" or 
they may have had this jumble of 
words. 

Once again, thank you and keep 
up your informative reporting. 

i. Mcdonald (Taupo). 

It's less hassle 
regularly 

Having difficulty getting your 
copy of "Bits & Bytes" regularly? 
We suggest that you become a 
subscriber. If you prefer to buy from 
your bookstore or computer shop 
place a regular order. This will help 
ensure you always get a copy. 



12 




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End of the series 

Computer graphics is now recognised as a major form of 
computer addiction. A great deal of thought goes into deciding just 
what a particular microcomputer will offer you for graphics .... 
and a good deal more thought goes into designing tempting add-on 
devices that you can buy at a later date. Such devices can help 
you enormously in creating, displaying or interacting with graphics. 
Some are cheap and some are expansive. 

This last article in this series outlines some of the clip-on 
graphics devices available on small computers. Basically such 
devices can perform one or more of four functions. They can help 
you create graohics more easily; they can help you display better 
graphics and fnally they can help you process graphics more 
effectively. 

The clip-on path to 
better graphics 



65 PITT St.. AUCKLAND 
Ph. 399 655 



By PIP FORER 



The most common graphics 
add-on that can be found is the 
paddle, often called the games 
paddle- The Apple II at one time 
came complete with a pair. Today 
many people purchase them at an 
early stage for an easy entry into 
the world of computer games. The 
paddle is usually a very simple 
analogue device with a rotating 
knob (connected to a 
potentiometer) and a simple 
on/off fire button. It relies on the 

user's software for interaction 

with the screen. 

All the knob on the paddle does 
is return a value in a certain range 
(typically to 2551 which is 
determined by the position of the 
potentiometer. Statements in 
BASIC or machine code translate 
this value into a screen position 
for drawing. Ttie user's eye then 
appreciates this position on the 
screen and adjusts the paddle 
appropriately to affect the image 
he Is getting. A single paddle is 
usually used to allow the user to 
control an object moving in one 
direction, say [he laser turret in 
Space Invaders. Two paddles 
allow control in two dimensions. 

More seriously, paddles are 
often used in screen creation 
utilities; for instance, to position a 
cursor for the start of a label or for 
locating a shape to be drawn. 



A more sophisticated version of 
the paddle is a type oi joystick 
where movement of a joystick can 
capture two potentiometer values 
at once, one for X and one for Y 
co-ordinates. The principle is 
identical to having two paddles 
but is made mechanically easier 
for a human hand to cope with. 
Musi Apple juyslicky are of ihis 
type. 

A second type of joystick is one 
where a direction rather than a 
position is sensed. This is typical 
of Atari joysticks, the most 
publicised of which is "Le Stick", 
a free-standing column in which 
direction is sensed from the 
simple angle of the hand holding 
it. Joysticks such as these return 

codes corresponding to directions 

of tilt (up, down, left, left and up 
etc), usually returning nine 
possible states. These correspond 
to stationary and the eight sectors 
of the compass <N, NE, E, SE, and 
so on). Again the link to a program 
consists of sensing the codes 
returned by the joystick and acting 
accordingly, In the case of 
controlling the movement of a 
shape on the graphics screen you 
would need to check the joystick 
response. If it was "move up and 
left" then the X and Y values of 
whatever you were drawing to the 
screen would have to be adjusted 
to do this. 

The main operational difference 
between the two types is that the 
latter sort requires you to check 
that your object stays on the 



14 



GRAPHICS 



screen while the former ones can 
be scaled to ensure that the 
screen boundaries are always 
conformed to. 

Joysticks and paddles come in 
various qualities (in terms of both 
ruggedness and purity of 
response) and are fairly cheap. 
Other means of screen interaction 
are more expensive. The most 
popular is the light pen. Light pens 
can be used to simply point at a 
display screen so that the 
computer records where the pen 
is pointing. This is a bit more 
direct than piloting a cursor 
around with paddles. It differs 
from paddles and joysticks by also 
involving the screen directly. Most 
decent light pens sense the 
location of the pen by very 
sensitive timing. The screen on a 
monitor is refreshed regularly by 
an electron beam and a sensor in 
cheap light pens actually picks up 
the passage of the refresh beam 
over the screen. By comparing the 
time at which this is sensed with 
its knowledge of where the 
refresh from the CRT should be at 
that point in time it can calculate 
tha X and Y positron nn (he 
screen. 

A word of caution. Because of 
timing rates that differ American 
light pens give peculiar results on 
New Zealand machines using 
standard monitors. This is 
because the refresh rates vary in 

certain countries. Also the poorer 

pens only give a limited standard 
of accuracy. Machines with built- 



in monitors (such as most of the 
Japanese machines) are able to 
offer a far higher accuracy of 
response than machines with ad- 
hoc display units. Many 8-bit and 
most 16-bit machines now offer a 
light-pen port. 

Finally there ere mice. A mouse 
is a small, hand-held device which 
can be moved by the hand over 
any flat surface and translates its 
own movements into a cursor 
movement on the screen. The 
mouse achieved a small fame with 
Xerox, which used it for screen 
interaction with a language 
developed at its Palo Alto research 
centre and called Smalltalk. It has 
recently found wider publicity as 
the main interactive device 
employed by the new 32-btt Apple 
Lisa computer. The computer 
press have applauded it, Others 
are imitating it but you will need 
almost SUS1O.0O0 (and I suspect 
some patience) 10 get within strike 
of one just at this moment. 

Capturing graphics 

The second sort of peripheral is 

aimed at capturing an existing 
pattern on the computer. The two 
most common clip-ons in this field 
are bit pads (alias graphics tablets, 
alias digiiisers) and video- 
digitisers (alias frame grabbers). 
These are typically quite 
expensive peripherals but 
extremely time saving. 

Bit-pads are the most common 
graphics peripheral after paddles. 

The basic aim of these devices is 



to allow the user to draw 
indirectly on the screen through 

using a hand-held pen or cross- 
hair cursor. In general they are 
used where an existing line- 
drawing exists (say an outline of 
New Zealand, a cartoon character 
or a diagram) and the pen can 
trace the design from a table top 
and see it appear on the screen. 
This has great attraction for the 
99 per cent of computer users 
with limited artistic talent and/or a 
dislike of coding long strings of 
co-ordinates. Using such a device 
a complex shape, such as the 

North Island, can be encoded to 

the screen in a few minutes. The 
information coming in from the 
pen can also be used for other 
tasks, such as calculating the area 
of a shape by drawing around its 
exterior. Geography students use 
this regularly to calculate the area 
of water catchments for instance. 

The digitiser really is a great boon. 

Unfortunately good ones are 
expensive. If you digitise 
information or shapes from large 
Lands and Survey map sheets you 
need both a large digitiser (able to 
deal with 30 in. by 40 in. maps) 
with very high accuracy (down to 
1/100 in.) That is a five-figure 
piece of equipment. The high 
quality, smaller models weigh in 
from S1500 upwards. These 
usually consist of a flat tablet 
perhaps 30 cm. square which is 
connected to the computer by a 
cable. A pen, also connected to 
the computer, allows you to trace 



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15 



GRAPHICS 



lines. The principle of operation 
involves a fine mesh of wires 
embedded in the tablet and more 
fine timing. Essentially readings 
from the wire mesh and the pen 
tip are compared and the timing of 
signals allows the position of the 
pen tip to be computed. 

These digitisers are accurate 
but expensive. For many 
microcomputers, whose owners 
simply want to draw a picture on 
the screen, the accuracy {and 
cost) is unwarranted. A cheaper 
set of digitisers exists using a 
hinged arm to calculate position. 
The hinges contain potentio- 
meters (useful things that they 
are) and as the hinge is opened or 
dosed the angle (and setting) of 
the potentiometer changes. From 
this the position of the cross-hair 
can be calculated and an image 
traced from a table top to the 
screen. Such digitisers need no 
special table but still serve only a 
limited size dictated by the length 
of their arms. An American firm 
(Penguin Software) has taken the 
whole idea one step further by 
having such a device that records 

3-D ahepoa. It markets this with 

software that displays such 
shapes straight on the screen in 
perspective •from any angle. 

Far less common but an area of 
increasing interest are the video 
digitisers. These simply take the 
input from a television camera and 
convert this into a computer 
graphics picture. The incoming 
signal is broken down into a 
particular grid of pixels (say 256 
by 256) and stored in graphics 
RAM just like any other picture. 
From here you can superimpose 
on it. clear bits out or modify it. 
The capture is fast, sometimes 
one-fiftieth of a second, and the 
image often good. These devices 
are the basis of "computer 
photography" side-shows. Until 
recently most cheap video 
digitisers needed American 
standard NTSC input so a New 
Zealand user might need a special 
camera for the task. British 
manufacturers have begun to 
produce systems based around 
PAL which may offer a better 
option for us. If you own a camera 
already (a big it) video digitisers 
are about the cost of a low-grade 
bit pad. 



Better graphics outputs 

Graphics s essentially about 
display, either hard copy or soft. 

With soft (fcreen-basedl output 
you can enhance your image by 
essentially buying a better 
monitor. The problem is that a law 
of diminishing returns per dollar 
spent sets in. Rough video is 
cheap: you use the television. If 
you ere dissatisfied with that a 
proper colour monitor of the large- 
volume production kind is 
relatively cheap. If you go for a 
basic RGB monitor it should cost 
you less thar a home television. It 
gives a calmer picture- 
Incidentally, RGB stands for red, 
green, blue, the three colours of 
the individucl colour guns in the 
set. RGB monitors are quite nice 
since on some machines you can 
interface them to the computer 
throug h software-programmable 
cards. These can be programmed 
to set a background colour (set 
one gun on all the time), delete a 
primary colour (disable a gun) or 
give coloured text on a machine 
that does not have such a facility 
inbuilt. However, most low-cost 
monitors (and ceitainly all 
televisions) have an upper limit to 
the number of dots they can 
resolve. On most it is under 300 
points vertically. To improve on 
this requires special circuitry 
(which is higher cost and 

produced ir smaller volumes). 
These monitors employ a 
technique called interlacing to 
extend the resolution. 

Thus the ACT Sinus gives 400 
by 800 points monochrome while 
the astonishing NEC Advanced 
Personal Computer (not to be 
confused wilh the PC8000I offers 
800 by 640 colour on its built-in 
monitor. Resolution above this 
geis progressively more 

expensive. 

The othc peripheral is the 
printer. Black and white graphic 
printers are now commonplace. 
The great growth recently has 
been in colour printers. Although 
exotic ink-jet ones exist in the 
over $7000 price range, matrix- 
dot printers offer colour at under 
half this price. Their operation is 
through a ribbon with at least 
three horizontal coloured stripes in 
it. To Create a Coloured screen 
merely requires the printer to pass 



,—..,.,._■ 



several times over with the 
required mix of the primary 
colours being struck. A screen 
dump can take three minutes with 
this but the effect can be striking 
and cheap. 



Putting punch in 
the processing 

The final graphics option is to 
upgrade your processing power. 
This can be done with one of 
several options. The most 
common is to firstly increase the 
size of your memory. This just 
allows more graphics screens to 
be stored in the computer and 
rapidly accessed. The next option 
is to increase the speed of your 
processor. This means (for those 
machines for which it is available) 
possibly a second processor that 
is faster or one designed 
specifically for processing 
3-dimensional data bases. Such 
add-ons are available for certain 
machines. Finally you can do a bit 
of both. It seems fair to end up 
with the Apple II for an example of 

thi? If ynu am constrained by 

normal Apple graphics then 

roughly SI 400 will get you a 

board with RAM, a graphics 
processor and 5 1 2 by 5 1 2 pictu re 
resolution. That might be one way 
to stick with a familiar system but 
pursue new heights. You will have 
to get a better monitor to cope 
with it though. 

The main lesson from this 
discussion, and the preceding 
articles, is the complexity of any 
computer system, even a 
microcomputer. The use of 
graphics involves a whole 
spectrum (acknowledgements to 
Clive Sinclair) of techniques and 
equipment and all must be well 
matched. Good programs, fast 
processors, friendly interaction, 
good resolution are only part of 
the whole. There is little point 
having a great computer and a bad 
monitor or a super program but a 
weak processor. If you want to 
get into this area, or are already in 
it, mix and match intelligently to 
build a system that fits your 
budget, uses all its parts fully and 
does the job you want done. 



16 



FARMING 



— i^W.'UVWM W IHWMP i 1 ■' ' ' 



......... --.,., ,.u ..... ,,,, 



Getting at the beast 



by CHRIS McLEOD 

Should you be using a computer 
on your farm, and if so, in what 
ways can you get access to a 
computer. 

There are three reasons for 
farmers using computers on the 
farm: 

• If you are interested in 
computers and their application 
on farms, you may want to use 
one as a hobby. 

Any benefits you gain could be 
considered a bonus; they are not 
essential in fulfilling your aim. As 
long as you get personal 
satisfaction and can afford to use 

the computer, then that is reason 

enough. 

• If you would like to improve 
some aspect of your farming 
operation, but not necessarily 
improve your financial position 
(eg, improve per head stock 
performance). 

A computer could help but you 

must carefully evaluate the 
software availablu lu wnsurw yuu 
can use a computer to achieve 
your aim. It would be best to seek 
advice from someone familiar with 
both farming and the computer 

software available. Again, you 
must be able to afford to use a 



computer. 

• If you warn to increase the 
profit from the farm, a computer 

could be used to help increase 
income and/or decrease 

expenditure. 

This is the most likely reason, 
and involves the most work in 
evaluating software, costs and 
benefits. Unless you have a good 
knowledge of what software is 
available, how you can use it, and 
how you can put a dollar value on 
the benefits, I strongly suggest 
you seek advice from someone 
who does. 

Farmers who already own 
computers, farm consultants, and 
computer consultants would be 
the best peop'e to talk to (but 
remember some farm consultants 
may not be familiar with 
computers). 

Idea — Before you commit 
yourself, you must have an idea of 
the annual cost of using the 
computer (including any extra 
time needed tc collect and enter 
the required data), and the annual 
financial benefits. Some costs and 
benefits are quite obscure. For 
example, what value do you give 
to better manacement information 



which will allow you to make 
better decisions. 

Now we will look at the various 
ways you could get access to a 

computer. 

There are several ways you can 
make use of a computer without 
using it yourself. This could be 
through farm consultants; 

accountants; farm secretaries 
working for consultants; 
accountants etc; stock firms; 
dairy companies; data bank 
accounting service; and bureaus. 

Several farm Consultants are 
now using computers to process 
information from clients' farms. 
They can more easily derive useful 
management information from 
financial information such as you 

would provide for your 

accountant. They can use this to 
advise their client, or give the 
information to- the client for his 
own use. 

Because of the amount of work 
involved in maintaining physical 
records, most consultants would 
restrict the use of their computers 
to financial information. The 
advantage of using a computer in 
this fashion is that the cost is low, 
and the consultants can provide a 
great deal of information and help 
which a computer could not. 

Most accountants now use 
computers to process their 



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17 



FARMING 



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clients' data, but very few provide 
anything more than a set of 
accounts — useful for the tax 
man, but not ideal for 
management purposes. Much of 
the information which could be 
used for management decisions is 
there, but not in a form which can 
be easily interpreted. 

At relatively little extra cost, 
accountants could provide 
farmers with a considerable 
amount of information which 
would be useful for management 
purposes. We hope to see more of 
this in future. 

If farm secretaries were to carry 
a computer around with them, 
they could collect information far 
more easily. This would have little 
effect on you as a farmer. If 
however, the farm secretary 
carried a range of programs which 
you may want to use, then a 
bureau-type service could be 
provided. 

Stock firms use computers at 
present to process their own and 
farmers' data, but generally for 
accounting purposes (the 

rinmments. about accountants 

would apply). We may soon see 
changes in this area, however, 
with stock firms offering bureau 
type services. Dairy companies 
are similar to the stock firms. 

Data Bank runs a sophisticated 
bureau service where you can use 
a computer to carry out relatively 
sophisticated financial analysis 
and control. This system uses 
coded checks indicating 

categories of income and 
expenditure as well as journal 
entries which you make and send 
in by post or deliver to a bank. 

Once you have an 



understanding of the system and 
how to interpret the results, it can 
be most use'ul. The cost is quite 
reasonable. 

Bureau - Bureau services 
generally wcrk on a mail-in/mail- 
out system where you enter the 
appropriate information on a 
coding sheet, then send it to the 
bureau whera it is processed. The 
results are mailed back to you. 
The type of work and cost varies 
considerably. 

There are several ways you can 
get access to a computer you can 
use yourself. These are: full 
ownership or lease; syndication 
ownership (group ownership); 
information system where you 
use your own terminal; bureau 
system where you use the 
computer ycurself (basically hire). 

Full c-wne-ship or lease has the 
most flexibiity. You can do what 
you want when you want. For a 
dairy or stud farmer who make 
almost constant use of the 
computer, this is the only viable 
alternative. 

Often, a farmer with his own 
computer may use other 
computers, such as the bureau 
service provided by Sheeplan. If 
real-time data acquisition and 
control is being considered, your 
own computer is the only option. 

Sharing ownership with others 
may be possible if you do not need 
a computer all the time. If you 
were going to carry out financial 
analysis and control work, with a 
small amount of physical 
recording, then this may be OK. 

As in any syndication of 
equipment, the rules of who can 
use the computer and when, 
should be clearly stated before 



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purchase, otherwise disagree- 
ments and arguments could ruin 
good friendships. Always keep 
the syndication on a business, not 
a personal basis. 

Cheap - This could be a 
relatively cheap method of getting 
access to a computer for many 
farmers. One way to establish a 
"syndicate with minimum cost is to 
follow the example set by a group 
of farmers and a programmer in 
Canterbury. They bought a 
computer for the local high school 
(saving the 40% sales tax) and 
have use of it in the evenings; the 
school uses it during the day. 

Although I know of none 
operating in New Zealand, 
Information systems could have a 
place in farming. An information 
system can take many forms, but 
in computing, this generally 
means a large computer which 
stores a great deal of information 
on one or more subjects. 

It is used like a library. By linking 
up to the computer with a terminal 
(keyboard and screen) or another 
computer, you get access to 
information in the large computer, 
The best way to use such a 
system would be to have your 
own microcomputer for most of 
your work, then when you want 
to tap the information system, you 
link your computer to the big 
computer by telephone. 

With a bureau system where 
you use the bureau computer 
yourself (instead o1 mailing the 
information in), you could travel to 
the bureau office or have a 
terminal. With computer 

equipment still relatively 

expensive, this could be cheaper 
than using your own computer, 
although not quite as convenient. 

If you are considering any of 
these alternatives, you must still 
carefully evaluate the costs and 
benefits of eech system. If you do 
not own your own computer, the 
inconvenience of the other 
alternatives must be valued as a 
cost, 

Naxt month, we will look at 
what should] be considered when 
determining the costs and 
benefits of owning a computer. 



18 



BUSIN6SS 

Final selection 

By JOHN J, VARGO 

Last month, we evaluated the 
vendor proposals and reduced our 
list to the most promising 
candidates to supply our small 
business system. We will now 
look at the process of making the 
final vendor selection and 
implementing the chosen system. 

Final selection - Having 
chosen your short list of potential 
system suppliers, you now need 
to determine their ability to deliver 
what they have promised. Your 
selection was based on their 
apparent ability to meet your 
needs and the cost/effectiveness 
of their system. 

Final evaluation of vendor and 
system capabilities will include: 

• contacting current users for 
their opinions and experiences 
with the vendor and the system 
you are planning to install. 

• testing the system with 
typical input from the proposed 
user environment. 

• evaluating documentation for 
hardware anU software. 

• appraising printed reports 
and CRT displays for suitability of 
format, quality and flexibility. 

A System may appear to meet 
all your needs and be very 
effective on paper. But when it is 
measured in its natural business 
environment for ease of use, 
vendor maintenance support etc, 
it may be found wanting. You 
need to discover before you buy if 
the real capabilities match up to 
the purported ones. 

Contacting current users — 

.To obtain names and addresses of 
current users on your short list, 
just ask your vendors. They 
should be pleased to provide such 
a list. But if they are hesitant, this 
may be an indication of the quality 
of service provided in the past. 

A phone call may be convenient 
for initial contact to determine the 
user's willingness to provide such 
information. The user's final 
response however should be in 
writing so that there are no 
misunderstandings about your 
questions, and to ensure clarity of 
responses. 

You may choose to prepare a 
"user questionnaire" which 



states the infoTnation you require 
and may provide a scale for 
response from 1 (very poor) to 5 

{excellent}. Here are some 
questions you may want to 
include: 

• How has vendor support 
been in terms of hardware and 
software maintenance? 

• Has the hardware been as 
reliable as you expected? 

• Has technical and user 
documentation been up to your 
expectations? 

• Have vendor training 
sessions been satisfactory and 
sufficient in scope to prepare your 
employees for using the new 
system? 

• Have there been any other 
areas you have found particularly 
troublesome? 

• Any areas you have been 
particularly pleased about? 

Based on the results oi the 
questionnaire, you may want to 
clarify certain points with the 
vendor, or include certain items in 
your contract. 

Testing the proposed 

Systems — Tasting the 

proposed systems is the key 
evaluation tool. A few days of 
thorough testing at this stage can 
save months of frustration later. 
Tests should be performed using 
samples of sctual transactions 
from your business selected to 
provide as wide a range of 
circumstances as possible. 
Transactions should include very 
small and very large dollar 
amounts, as well as erroneous 
information of every variety. 

The testing process will 
determine the suitability of the 
system to your working 
environment, as well as testing its 
reliability and error detecting 
capabilities- 
Documentation - Since the 
system you choose will be used 
for five years or more, it is 
important the original 

documentation is sufficient to 
train future errployees as well as 
provide an ongoing reference for 
current users. There should be 
user and technical manuals for 
hardware and software 

components. 

All user manuals should be 
clearly written and indexed so that 



■™ „*, 

a first-time user can read it and 
not feel threatened. At the same 
time, manuals should be complete 
enough to be a useful reference to 
the experienced systems 

designer. Unfortunately, not every 
manual may meet these 
guidelines. 

Appraisal of output - The 

printed documents and reports 
from the system, as well as the 
screen layouts, should be 
approved by the manager/users 
and operator/users. If the people 
who will be using the system are 
not satisfied with the final output, 
we may find the whole system 
failing. We must always 
remember the people in the 
business are a key element in our 
information system and the 
success of the installation 
depends on their enthusiastic 
support. 

Printed reports and screen 
formats should be easy to follow 
and as similar to the manual 
system reports and forms as 
possible. This requires flexibility in 
the system and good 
communication with users. This is 
aleo on opportunity to evaluate 
the quality of the printer proposed 
for the system, and the quality 
and stability of the CRT display. 

The contract - By this time in 
the evaluation process, it has 
probably become apparent which 
vendor is your top choice. A 
contract should be drawn up to 
formalise your choice and spell 
out the responsibilities of both 
parties. As a minimum the 
contract should include: 

• a specification of the hardware, 
software and training to ba 
provided by the vendor 

• delivery dates and a program of 
implementation, and related 
payment schedule 

• a specification of the 
maintenance program for 
software and hardware, and the 
related costs 

• any site preparation which 
might be required for the 
hardware. 

These are minimal suggestions, 
and it is recommended you 
contact your solicitor for further 
advice. 

• Next month, John Vargo will 
discuss the implementation of 
a new system. 

19 



€DUCflTION 



The mechanics of a 
network 



By NICK SMYTHE 

This article focuses on a few of 

the major questions and evaluation 

issues surrounding microcomputer 
networks. To do 1his we will refer to 
several networking systems 

available for the microcomputer 
systems that have attracted most 
interest: the Apply, Poly and BBC 
Microcomputer. At present the 

comments are largely secondhand 
but perhaps at a later date we can 
return to report on some "hands- 
on" experience. 

1 1s a network cost-effective? 

The first part of this issue 
depends on how many stations you 
want to have and what sort o1 disfcs 
and printers you want. Basically the 
more computers the bettqr the 
economics since for each station 
you save on a disk and printer. You 



can use that money either to get 
better disks or printers or to buy 
more computeis. Nothing is this 
simple though so go to 3 to see at 
least one caveat on this comment. 
2 Will it lose my flexibility with 
machines? 

Usually no. Mjost networks enable 
you to plug machines on or off with 
little trouble . Tha machines you take 
off are as autonomous as the 
equipment you have. If you have 
some small spare disk drives then 
you can take any machine away and 
use it as an independent micro 

wherever you want. Later on you 
can plug it back in. The real 
question here is whether the extra 
disk drive is available. An alternative 
to full detachment is linking a 

microcomputer in to the network 

cable at another point. However. 

there are limits on how far a 

network cable can stretch without 

extra equipment. 

3 Can I add any number of 

computers on? 



In theory some networks have the 
capability to recognise a large 
number of machines. Some of the 
Apple systems and Econet offer 255 
stations for instance. This is a little 
spurious since as you add machines 
a nasty phenomenon called 
system degradation sets in. 
Essentially this is a microelectronic 
traffic snarl-up. 

Each user is fine while he is using 
his own processor but whenever he 
uses the network to share things he 

has to compete with other users. 

Once you get into large numbers of 

users this competition can slow 

things down a lot. The number you 

can sustain depends on your use of 

the system. If your use is disk or 

printer intensive the number will be 

be lower than if most of the work is 

done by independent machines. 

One way of looking at a network is 

that you want users to get a fast 

response time. Slow response, say 

to a disk load, may indicate either 

slow disks or slow transfer along the 

wires or excessive queues. The last 

category is the real killer and can 

occur with surprisingly few users 

in some cases. 




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M i"«f«^ W»l" i l H 'M —l»l 



A Will I need expensive peripherals? 

This again depends on your 
requirements. Networks become 
unattractive when they stow right 
down. Although the worst culprit is 
user competition, clearly better 
peripherals can ease this a lot. Hard 
disks, lor instance, can perform at 
an average of 10 times the speed of 
floppy disks and thai can clear a lot 
of queued jobs quite speedily. 

The disk drive is particularly 
important if you solve your printer 
demand problems by saving printing 
requests temporarily to disk. The 
currently cheaper 5 V* in (loopy 
drives arc slow and have a small 
capacity. The spooling can run out 
of disk storage room. Most 
common 5in drives are in the 100- 
180 kilobytes range. Recent ones 
get to 400K. The 8in floppy is faster 
and larger. Best of all is the hard 
disk which has access times 
typically an order lower than any 
floppy and stores from 5 megabytes 
(million bytesl upward. Hard disks 
seem made for networks. 
Furthermore cost competition 
overseas is driving the price down 
very fast, A hgrd disk with 5 



megabytes should be available for 
under $5000 (educational price) in 
1983. In fact ihe Fanasonic 3001 16 
bit computer now marketed here is 

already rumoured to be more than 

shaving that threshold. 

While we are on hard disks it is 
worth noting thai the sort schools 
can afford do not have changeable 
platters as a floppy drive does. The 
disk is sealed in its container. The 
corollary of this is that you need a 
back-up system tc hold your files in 
case the hard disk crashes. This 
may be a tape or a floppy drive or 
both. Formac Marketing in 
Palmersion North is working on an 
interface to permi: back-up storage 
to a videotape recorder and this may 
be a cheap possibility. The Corvtis 
system for the Apple has a similar 
facility. Running a hard disk means 
more thought is given to a lot of 
matters regarding file security and 
who has what file space. This is 
such that most networks would 
want a floppy driv? and a hard disk 
drive just for user flexibility. 
5 What is a Megabaud netv/ork? 

Another reason ;hat networks are 
slow is that their transfer rate is 



slow. The cable in a network allows 
the transfer of data from various 
devices attached to it. The speed of 
this transfer is governed by the 
cable and by the transmission and 
reception ports in the computer and 
peripheral. Some networks are slow 
and some very fast. Some will meet 
small needs and some major ones. 
You can get an idea of what is 
involved by considering the baud 
rate of networks. A baud is the 
transfer of one bit (an eighth of an 
8- bit byte) a second. Network 
transfer speeds in our range vary 
between 9600 baud and 1 ,000.000 
baud with several on 250.0QQ. This 
Iranslates to 1200, 125,000 and 
30,000 bytes a second or, in 
practical terms, the transfer of an 
8K file (say a Poly or Apple screen 
image! would take 6 ■»• seconds, 
1/15 second, or about 1/4 of a 
second. As we noted there are other 
overheads in timing. These may be 
so significant as to dwarf transfer 
times. A small floppy loading the 8K. 
to the network would lake so long 
loading on any network that the 

Continued page 32 



HX-20 

PORTABLE COMPUTER 




The little computer with big 

performance 

The HX-20 is a lull- function, portable computer. 
Not a sophisticated calculator. 

Its standard 16KB RAM expands up to 32K bytes, or 
the 32KB ROM memory to 72 KB. 

This remarkable portable computer also communicates 
can connect RS-232C and serial interfaces to telephone c 
and other peripherals. 

The full-size ASCII keyboaid works just like a regular I 
its complete with built-in printer, a LCD screen and music generation via a 
piezo-electnc speaker. Full extended Microsoft BASIC Time and date (unctions. 

Compared to ordinary computers, Epson HX-20 offers six big 
advantages. 

1. Small size 2. Built-in power source 3. Automatic function keys 
4. Interfaced for peripherals 5. A Memory Saver 6. Costs less 

MICROPROCESSOR DEVELOPMENTS LTD 

24 Manukau Rd, Epsom Auckland 3. Ph (9) 540-128. Wellington Br.nth 1st Floor, World Trade Centre, Sturdee St.Ph W 851-917 
DEALERS: Auckland; Calculator Centre. Ph 790-328. D.E. and J Goldfinch, Ph 483-342, Southern Software, Ph 778-525, Smwll 
Systems, Ph 535-7389. Commu nicotians Specialists, Ph B76-W8. Twang*; Bay Computer* Ltd, Ph 83-633. New Plymouth; 
Taranakl Micro Electronics, Ph 84-067. Palmersion North; Vrscoun! Electronics, Ph 86-696. Wellington; Office Requisites, Ph 
721 -902. Dunedln; EcUpu Radio and Hobbles Ltd. Ph 778-1 02. 

21 



ATARI 



V*ww^<™wwi(Wrtynw«™ l i™--*w'*»~-bV.w™*- 



9 POKE 2*0:POKE 3,6:P0KE 9»2iP0KE 153S,7 
e:POKE 1537,64:P0KE 153S,185:TRfiP 17060 

1 itRAPHICS Ci:POKE 752,i:SETC0L0R 2,6, UP 
OSITION OA&i? ," ESCPPE r)QZE":POSITI 

ON 0,12:? ," G.C. ROBERTS" 

2 POSITION 0*145? ," 1382" 

3 FOR 1=1 TO 255 STEP 4: SOUND O,r,3,10:G 
OSUB I10005MEXT I 

5 FOR T=l TO l@:SETCOL0R 2,6, l: FOR D=l T 
56: NEXT D: SETCOLOR 2,6,7: FOR 0=1 TO 50 
:NEXT OiNEXr T:SOUNO 9,9,0,0 

&W!8JSi- W 23!? " EfiSV! N0T fis E 

3 FOR R=i TO 5: SOUND 0,TNT< RND< 1 >*256),1 

0*10:MEXT R:NEXT T: SOUND 9,6,8,0 

9 RET1 * «< (TflZE 1 >» 

18 GRftPHICS 7+16:C0LOR 2:G0SUB 2096 

« IPS! g*^ l5 *; '159,0,159,95,159,95,8, 
95,6,95,0,58,0,46,6,5 

13 DflTP 10,10/30,19,40,10,30,10,30,10,15 

9, 10,^9, 10,29,59,29,90,20, 100,29, 159,2 

0,30,39,49,30,50,30,70,30 

H °ft T Q 86,30,90,39,120,30,150,30,46,40, 

59,40,,0, 48, 109,48, 119,40,150,49,39,50,5 

0,59,39,50, 1 99, 59, 1 19,59, 159,59 



il 28 T ? ^^§'69,60,79,60,30,60,100,60,1 
59,69,4,-'0,30,79,54,79,99,70, 100,79,156, 
79*29,30,40*30,60,89,76,30 

16 DPTfi 99,80,159,80,24,90,50,99,70,90,8 
0,29,10,^0, 10,39,20, 10,20,60,20,30,20,93 
,30,20,30,40,30,59,30,60 

17 DATA 40,10,49,30,49,69,40,80,50,20,50 
,50,50,64,50,94,60,30,60, 70,66,36,69,95, 
70,2,70,10,70,40,79,50 

18 DfiTfi 80,39,80,69,80,70,80,39,90,16,90 
,38,30,50,90,79,96,74,96,95,160,30,109,4 
0,110#30#110,40, 993,999 

27 X=156:V=48 

28 COLOR i:SETC0LOR 2,6,0 

29 GOSUB 9090 

62 If PI0ZE=1 THEN IF X<60 AND V<40 THEN 
GOTO 27 

S3 IF X<1 AND V<56 THEN GOTO 3600 
64 GOSUB 7969 

55 COLOR l: SOUND 6.6,e,8:PL0T :■:,'■': COLOF: 
3: PLOT J, K: GOTO 28 
I960 GOSUB 16009 
1919 SOUND 6,64,10,8:GOTO 27 

2990 READ X,Y:IF XOS98 THEN PLOT X,Y:RE 
00 X,V:ORfiHT0 X,V:GOT0 2996 

2919 RETURN 



A-Mazing game for Atari users 



A game for Atari users calf-eri 
Escape Maze by G.C. Roberts of 
Te Kuiti. 

Requirernems: Atari 400/800; 
1 6K memory; Basic Cartridg e; one 
joystick. 

Game Objoct: To escape through 
all three mazes. 

Difficulty: Intermediate. 
Language: Basic. 
Graphics & Sound: Yes- 
Programme Line Analysis; — 

Lines 1-8: Introduction. Add 

the following lines if you want 
SYSTEM RESET to restart the 
Sarfte. 



O POKE 2.0:POKE 3.6:POKE 
9,2:P0KE 1536,76:POKE 

1537.64:P0KE 1 538,185:TRAP 
17000 
17000 RUN 

Lines 9-65: Ccmmands for first 
maze. Gosub 2000 reads Data 
lines (12-18) to draw maze. 
Gosub 9000 t-9090) gives 
joystick commands which control 
the moving pixel. These 
commands are same for mazes 2 
& 3 also. Line 8000 specifically 
gives time limit for all 3 mazes. 
Line 62 tests x.y co-ordinates for 
the invisible walls which if 



ATARI AND EPSON SOFTWARE 

Now available — N.Z. Designed Packages 

•it Accounts Receivable 

tV Hire Purchase 

<? Stock Control 

ir Television — Video tape rental packages etc 

Custom programming available for your needs 

Agents for Analog Software & Magazine for Atari users 
Full suppliers of all Hardware and largest 
Atari software agent in N.2. 



Conto<t Kevin Butler 

Communications Specialists Ltd., P.O. Box 15578, New Lynn. Auckland 



New rental premises opsninq Rpnl at 557 Rrccttfe Henderson. 



positive sends pixel back to start. 
Line 63 tests to see if pixel is at 
door of first maze. Line 64 with 
Gosub 7000 tests for pixel hitting 
wall (If positive Gosubs 
1 000- 1 01 0); Gosub 1 6000 
records number of wall hits- Line 
65 draws pixel with colour 1 while 
followed by colour 3 so as not to 
leave a trail. 

Lines 3000-4020: Graphics A 
sound commands for escaping 
first maze. 

Lines 4090-5180; Commands 
for second maze. Line 5157 is a 
test for sending pixel through to 
the third maze. Line 5159 with 
Gosub 14000 tests for pixel 
hitting wall. If positive Gosub 
1 3000- 1 30 1 gives the graphics 
& sound routine. If negative lines 
14020-14030 randomly draw a 
wall (14030) in maze at a low 
probability rate (14-020). Gosub 
1 5000 randomly places pixel 
somewhere else in maze as a 
result of being blasted & thrown 
from wall. 

Lines 5190-6090: Commands 
for third maze. Line 6075 tests to 
see if pixel is at door of third maze. 
If positive lines 8000 to 8070 give 
graphics & sound commands for 
conclusion & replay option. Line 
6080 with Gosub 7Q50 teM s for 
pixel hitting wall. If positive sends 
player back to start of first mazo. 



22 



3089 X=i:V=45:F0R T=l TO 3:F0R C=l TO 14 

:SGUtC 0*64*C*C:SETCQLOR l,C*C:FOR D=l T 

35: NEXT OrNEXT C 

3885 FOR W=l TO 28:NEXT H:NEXT T 

301S FOR C=8 TO 15 STEP 3:FOR 0=1 TO 10: 

NEXT D:SETCOL0R 4,C,7 

3920 FOR P=243 TO 31 STEP -7: FOR 0=1 TO 

51NEXT Da SOUND 0,P,i0,9:NEXT P:NEXT C 

3990 GRAPHICS 0:POKE 752,l:SETC0L0R 2,6, 

4 

4008 POSITION 0, IMPRINT ,,"C0NORATULATI 

ONS!" 

4865 PRINT **'YOU FOUND A HfiY AROUND THE 
INVISIBLE MALLS i " 

4020 SOUND 0,9,0, 0:FOR T=l TO 968: NEXT T 

4890 REP1 * <« HAZE 2 >» 

5090 HIT=0:nA2E=0:TinE=0:GRAPHICS 7+16:S 

ETCOLOR 1,8*10:COLOR 2: GOSUB 2060 

5100 DATA 0,0,159,0*159,0,159,95,159,95* 

0,95>0,95*0,50*0*48#0,0*20*10*50, 10*60*1 

9,150,10,1,20,30,20,40,20,66,20 

5105 DATA 80,20,140,20,20*16,20,29,39,0, 

30,10,10,30,38,30,90,30,100,30,44,30,50, 

50 

5110 DATA 36,30,60,30,110,30,140,30,10,4 
0,50,46,110,40,150, 40, 28,58,56, 5-5, 88,58, 
90,50,110,50,150.50,0,68,20,60 
5120 DATA 24,60,60,60,100,60,140,60,20,7 
9,40,70,50,78,76.70*80-79*148,78* 10,30,4 
8, 80, 60, S0, 150,80 

5130 DATS 10*40,10,56,20,50,20,95*30.20, 
30,30,50,30,50,40,58,64,50,95,60,10,60,6 
0*70,28*70, 70,S0>20.80.50 
5140 DATA 80,60,80,70,90,34,90,66,100,30 
,100,60,119,30,119,40,140,20,140,30,140, 
60,148,70,150,10.150.40 

5150 OATA 40,14,40.20,68,94,60,95.78,0,7 
0,10,110,59,110,56,150,50,150,80,999.999 

5155 X=156:V=48 

5156 COLOR i:SETC0LOR 2*0*0 

5157 IF X<50 ANO V<50 THEN SOTO 6088 

5158 GOSUB 9090 

5159 60SUB 14008 

5180 COLOR l: SOUND 0,0*0,8:PLOT X,V:COLO 
R 3JPL0T J*K":60T0 5156 
5190 RE(1 * <« HAZE 3 >» 

6908 TIITE=0: GRAPHICS 7+16:SETCOL0R 1.4,1 

Q: COLOR 2:80SU8 2800 

S#05 DATA 0,0, 159,0, 159,0, 159,95,159*95. 

0,95,0,95,0,60,0.50,0,0 

6810 DATA 10,10,50,10.60,10,90*10*100,10 

,149, 10, 18*- 20, 68.20*80,20, 130,20, 140.28. 

158,28,20,30,86,30,90.30, 1 19,30 

6920 DATA 130*30*140*38,1,40*29,40,50*40 

,140,48,20*50*30,50,54,59,130,50,10,60,2 

0,60,58*60.96*60*100,60*110*60 

6930 DATA 54,70,90,70,129,79,136,70,20,8 

0,30,80,48,80.60,88,70,39,148,80,18,90,2 

0,98*34,90*66,90,70,90,150,90 

6940 DATA 18,10,10,30,18,50,10*86*20*40* 
20,60,20,64,20,98,38,34,30,76,30,30,30,9 
5,48,30.40*80,50.20,50,39 

6058 DATA 50,40,50,76,50.30*50*30*60*1,6 

8*10,70.14,70*30.70,64,70,95,80,10,80,20 

,90,30,90,40,10.30,10,40 

6860 DATA 180*14,100,30,108*44*100,70,11 

3*60*110,30,120,28.129*36*120,60,120.70* 

140,10,140*30.140,40,148,70 

6870 DATA 130,50,130,60,150*20*150,58-15 
0,60.150,90,999,999 



6072 X=156:V=55 

6074 COLOR i:SETC0L0R 2*8,8 

6875 IF X<3 AND V<59 THEN GOTO 8080 

6676 60SUB 9080 

6830 60SUB 7059 

6090 COLOR l: SOUND 0,8,9,0: PLOT X,V:C0L0 

R 3: PLOT J. K: GOTO 6074 

7809 LOCATE X.V,A:IF P=2 THEN SOTO 1890 

7818 RETURN 

7859 LOCATE X,V*A: IF A=2 THEN RESTORE :G 

OTO 6 

7355 RETURN 

3800 X=i:V=55:F0R S=t TO 2: FOR 1=255 TO 

1 STEP -4: SOUND 0*1,18*18 

8005 SQSUB 10808: NEXT I 

9019 SETCOLOR 2*INT(RND<1 >*16>,8:NEXT S: 
FOR 1=255 TO 1 STEP -4:S0UND 0,1.8.10:60 
SUB 11 008: NEXT I 

3815 HAIT=18:F0R T=l TO 20: SOUND 0.INT<R 
ND<1 >*256^.10,18:6OSUe 128&0:NEXT ?:SOUN 

0,0.0.0 

3020 WPIT=3:F0R 1=1 TO 255 STEP 4: SOUND 

9,I,8*10:6OSUB 12980: NEXT I 

8025 SOUND 0*0.0.9 

8827 GRAPHICS 2=SETCOL0R 4.4,6 

3828 POKE 789,12 

8829 POKE 718.0 

3830 ? "PRESS THE TRIGGER TO PLAY AGAIN 

■ 

3840 FOR Y=l TO 598! IF STRI6<0>=0 THEN R 
ESTORE :GOT0 6 

8853 NEXT V: GRAPHICS 0:POKE 752,1 
8060 POKE 709*12:POKE 710,0: POSITION 0,1 
2:? ," THF END" 

8870 GOTO 8070 

9008 TirE=TIDE*-l:IF TIP1E=608 THEN GOTO 6 
9810 J=X5K=Y!IF STICK( 0>=14 THEN V=V-1 
9828 IF STICK<0>=6 THEN X=X+1 :Y=Y-1 
9038 IF STICK<9>=13 THEN Y=Y+1 
9840 IF STICK(9)=5 THEN Y=Y+i:X=X+l 
3850 IF STICK<0>=9 THEN V=V+1:X=X-1 
3068 IF STICK<9>=11 THEN X=X-1 
9070 IF STICK<9.>=18 THEN V=V-1:X=X-1 

9888 IF STICK<9>=7 THEN X=X+1 
9890 RETURN 

18000 FOR N=l TO 5:NEXT H:RETURN 

11088 FOR H=l TO 5:tCXT M: RETURN 

12080 FOR H=l TO HA IT: NEXT H: RETURN 

13880 60SUB 15008 

13905 FOR 1=1 TO 255 STEP 28:S0LN0 0.1.8 

,18 

13018 FOR T=l TO 15:P0KE 710*32+T:NEXT T 

:NEXT I: SOUND 8.0,0.8 

13912 GOSUB 16008 

13915 RETURN 

14980 LOCATE X,Y,A:IF A=2 THEN GOSUB 138 

88 

14020 IF RND<0>*290>1 THEN RETURN 

14930 TX=X:TV=V: COLOR 2:G0SUB 15900:PLOT 
X,V:G0SU8 15880: ORAHTO x,V:X=TX:Y=TV = RE 

TURN 

15000 X=INKRNtX0>*159>;Y=INT<RND<0>*95> 

: RETURN 

16088 HIT=HIT+l!lF HIT=4 THEN GOTO 6 

16810 RETURN 

17080 RUN 

23 



VIC 




graphic 
game™ 



ST*wDA«a 


VIC 


UKIEXA*MPEP 


ExMiotei) 


VIC 


m 3k 



By BRIAN BULLEN 
When I first got my VtC, I 
started at the front of the guide 
and worked as fast as possible 
through it. Every so often I'd) 
come across something that 
would) make me think "must 
come back to that". 

One of these was the section on 
animating with Peeks and Pokes 
(p61-65). It re-ntnded me of some of 
the first television games which 
appeared in New Zealand. 

I want to show how their program 
can be turned into a simple game, 
and introduce a few features of the 
VIC wa haven't yet looked at. 

VIC 
fix /amd ee 

above 

'$1^2* 





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UStA 










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SCREEM 


SC/tEEN 




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Erti 


Ty 




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AH tloM 





S oriM 



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Us£A 
H«H6iiy 





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337*7 



Memory map of bottom 32K of three versions of 
710 Memory Expansion. 



I suggest you reread the section 
in the guide. Be warned there is a 
mistake on p62, line 6 - the words 
row and column are interchanged. 

Now for the game. To their 
program, we will add a bat with 
which to hit the ball, controlled by 
the f 1 and f7 keys, a record of how 
many times the ball gets past us, 
and a timer to see how long we can 
survive. Enter the program listed 
below and run it. 

As it stands at the moment, it's a 
rather hard and unsatifactory game. 
To get the bat to move fast enough, 
you have to peck away at the keys 
like a woodpecker, but we'll do 
something about that later on. First 
let's have a look at some of the 
different parts of the program. 

Interest 

The first bit of interest is the 

TIS = "000000" in line 20. This is 
setting the VIC's built-in clock to 
zero so that we can time how long 
we play the game. 

Lines 230 and 240 then use Tl$ 
and extract the minutes elapsed 
using MID$(TI$,3,2), which picks 
out two characters of Tl$ starting at 
the third character In. Then the 
seconds are extracted using 
RIGHTS1TIS.2) which picks out the 
two rightmost characters of Tl S. 

This sort of technique can be 
used whenever you want to time 
something. You could even use it to 
turn your VIC into the most 
expensive digital clock on the 
market. 

The next lines of interest are 140- 
160. Line 140 uses the GET 
statement to see which, if any. key 
has been pressed. In most 
applications, the GET statement is 
used in a loop which makes the 
program wait until a key has been 
pressed. 140 GET PS:IF PS = 
"THEN 140 is the normal form for 
this. 

In our case, we most definitely 
don't want the program to wait. Try 
changing line 140 to that above and 
you will see what I mean. Line 150 
checks to see if the ft key has been 
pressec.' and, if so, moves the bamp 
the server Line 160 does likewise 
for the f7 key and moves the bat 
down, PY being the variable which 
determines rh e bat position . 

You could use any keys you 
wished. You would just have to 
chanqe the 133 and 136 CHH$ 



VIC 



MHMMMMMMMMM itedta ge d j «i ii is wmmwo •ftMNmMafHmMMMm 

values. -01 instance, if you wanted 
to use U for up and D for down, the 

values would be 85 and 68 
respectively. (Appendix J in your 
guidG has the values for all the keys). 
Alternatively you could use a 
statement such as IF PS = "U" 
TH EN... This has the same effect. 

Checks 

Line 170 checks to see if the bat 
has hit the ball (97 is the CHRS code 
for the bat). If it has hit, it reverses 
the ball's direction, makes the 
appropriate noise and goes back to 
line 60 to work out the ball's new 
position wfthout putting the ball on 
the screen. 

Now to deal with that 
"woodpecker" problem. The 
easiest way is to change the two 
control keys to N and Y. Then 
change lines 150 and 160 to start IF 
PEEK (37153) = 239 THEN... and IF 
PEEK (37153) = 247. Now you 
don't have to peek at the keys but 
simply hold down the desired key. 

This effect occurs because we ate 
taking advantage of the VIC's polled 



keyboard (that's another article in 
itself}. 

Make these changes and run the 
program. The game is far more 
playable, isn't it? 

However, there is still one 
problem to sort out. You should 
have noticed thatwhen you finished 
the game, it came up with the 
normal questicn, "ANOTHER 



GAME" and then a whole lot of Ns 
and Ys. 

Key 

The key to what is going on here 
lies in the fact there are exactly 10 
Ns and Ys. This is because the VIC 
has a keyboard buffer which stores 
the keys as they are pressed and 

Continued page 39 



Program listing 




10 PR I NT' 'IC LEAR)" 


165 


POKE 17680*21 * 22"PYI ( 97 


20 POKE 36879. 10S:POKE36878. 15:71$ 


170 


IFPEEKI7680-* X * 22"Y) -97THECJDX 


-"MOW 




- -DX:DY = -OY:POtfE36878.180i 


30 X=t:Y-lO:DX=1:DY-l:PY= 10 




GOTO60 


40 POKE 17880 + X-4 22^1.81 


\m 


GOT040 


£0 FORT - !TO10:NEXT 


zoo 


C-C-1 


60 POKE(7680(X'-22 , Y),32:POKE(7680 


?iu 


Y INTIRN0<1P23I:X = 1:IFC *20 


*2H-22 , PY>.32 




THENPY- 10:RETURN 


70 X = X + DX 


vw 


P0KE3W79,27:PMNT"KtfAfl, 


80 1FX = OTHEND3U-DX:POKE363?6.220 




0OWN.3RIGHTJGAME OVER" 


90 IFXX1THENGOSUB2G0 


■m 


PRINT" YOU SURVIVED FOR "• 


lCO Y-Y+DY 




MIDS(Tt$.3.21 


110 IFY-OORY = 23THEPJDY = -DY:POKE 


740 


PRINT"MINUTES & "; RIGHT* HIS, 


36876.230 




21;" SECONDS" 


130 POKE36876.0 


260 


INPUT"ANOTHER GAME";RS 


140 GETPS 


m* 


IFLEF7SlflS,l|-"Y"THENO0: 


150 IFP$=CHR$(133>THENPY = PY 1: 




GOTO10 


IFPYOTHENPY -0 


270 


PRINT"GOODBYE FOB N0W;EN0 


160 1FPS-CHR$n36)THENPY = PY*l : 




READY 


IFPY>2?THENPY = 22 







The Portable 
Business Computer 



CONTACT YOUR LOCAL DEALER NOW! 




$3815.00 

This includes double density! 




yVCifju5 



2 Manukau Rd Epsom Auckland 
Phone (09) 544-415, 504-7S9 
y\ ^J) Siptcm* visit our showroom. 



AUTHORISED N£W ZEALAND DISTRIBUTOR 



OSBORNE DEALERS 

COMPUTER WORLD LTO: Cnr Lome A Victoria Sts. Auckland 

Ph31-394 POBOK967 Ms <^ fttfwii. Minagar. 
FINANCIAL SYSTEMS LTD: 161 -163 JervosRd. Home Bay, 

Auckland. Ph 789-068 or 789-069 (Specialists in financial 

modelling). PO Box 46 068. Heme Bay. Or Mike Snowden. 

Director. 
MACH1NEHEAO COMPUTER CO: 9 Mormon St, Auckland 

Ph 77 1-566. PO Box 47-0&3 Mr Warren Wil&Ort. D-erfor. 
TECHNOLOGY RESOURCES LTD: 8 Thackeray Si. 

Hamilton Pt> 393-801 . POBox4063. Mr Wally McKenzie. 

Director 
WAIKATO COMPUTER CENTRE LTD: 6 Pnnces St. MamJlon. 

Ph 393-416. PO Box 1C94, Mr Bob Dean. Dwoctor. 
THE COMPUTER SUITE LTD: 84 Efuora St. Rotorua. Ph 497-507. 

PO Sox 1 858. Mr Stove Peacocke, Director 
LAKELAND TV & STEREO: 43 HOfomatanQi &. TaupQ>. Ph 88-868. 

PO BO* 892. Mr Harry Leusink. D-reckx. 
TIMMS' BUSINESS EQUIPMENT LTD: Tennyson Sl ( Napier. 

Ph 54-250. PO Box 308. Mr Nevlllo Bannister , Sales Exec. 
CQMPUSAL6S SOFTWARE * HARDWARE LTO: 7$ G- u: r»e* St, 

WeBrfllcn Ph 728-658. PO Box 11-819. 

Mr Warren Cardno, Director. 
EINSTEIN SCIENTIFIC LTD: 1 77 W*s St. WeDirigton. 

Ph 85 1 -055. PO Box 27-1 38. Mr Raju Badianl. Manager. 
SMALL BUSINESS SOFTWARE LTD: 2nd Floor IBIS House. 

Ph 64-617. 183 Hereford Street, Chr-sfchurch. POBox 1013. 

Mr Bruce Foufds. Managing Dxoctor. 
ECLIPSE RADIO & COMPUTERS LTD: 134-136 Stuart St. Dunotiin 

Ph 77 8-102 PO- Box £270. Mr Stuce McMillan, Manager. 
LEADING EDGE COMPUTERS LTD: South City Mall. Ounedin 

Ph 55-268.PO Box 2260. Mr George Orr 4 Mrs Elaine Orr . 

LVectors 



25 



Panasonic 




FUNCTIONAL SPECIFICATIONS 



• Microprocessor 

Model: MN180O (equivalent to 6802) 
Clock frequency: 890KHz 
System Reset Function 

• Memory 
BOM: 8K Bytes 
RAM: I6K Bytes 
Video RAM: 1K Bytes 



• Keyboard 

System: Sottwaie scanning 

Keys; 5-shlft key mode with 45 keys, SHIFT key and CTRL key 

• Display interlace 

Screen size: 24 lines x32 characters 



Characters: 64 characters witu 6x7 dot matrix 

64 semi-graphic characters with 8x 8 dot matrix] 
Characters & symbols specified by user: 32 characters with 

SxBOotmairix 
Attribute: Inverted display function 
Composite video signal: with 75 ohms, W p-p or with 
BF flip-Hop converter 
•Cassette Interlace 
System: FSK system 1.200Hz (space), 2,400Hz (mark) 

Baud rate: 600 Bauds 

• AC Adaptor 
Input Voltage: AC 1 10V, 120V or 220V*10°/o, 50r60Hz: 
Output Voltage: DC 17V. 7.8V and -8V 
Power Consumption- 12.5V/ 

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•mnvmay »•*-■"»)-"' 



Living with 
accidents 

By GORDON FINDLAY 



In my job, and because corn- 
puling has become my main in- 
terest outside work as well. I see a 
lot of software. Much of it is 
pretty hard to work with. 

This includes a lot of commer- 
cial software - it is hard to love a 
system in which an accidental 
press of a particular key can 
destroy all of the last two hours' 
work. Vet this is just what hap- 
pens with Apple Logo — hit 
RESET (which is right next door to 
RETURN, for heaven's sake) and 
you are completely sunk. 

And what about the programs 
which die when you make a little 
typing error? 

A little programming can get 
around these problems. 

Here are soma techniques for 
making your programs easier to 
work with. The main thing is to 
make input as painless as possi- 
ble. This usually means avoiding 
the INPUT statement, which is far 
too inflexible for most purposes. 

This first routine is pretty ob- 
vious — it simply scans the 
keyboard until a key is pressed, 
then returns to where it was call- 
ed, with ZXS containing the key 
pressed: 

10010 ZX$=IWKEYS: IF ZXS = " 
"THEN 10010 ELSE RETURN 



Notice there is noth ing at all bet - 
ween the two quote marks — we 
are comparing ZXS to the null 
string, not a blan<. 

Input given by ihe user of a pro- 
gram should always be checked. 
A program will usually crash if a 
string is given rather than a 
number. Using The INPUT state- 
ment isn't all that helpful — here is 
a subroutine you can use to input 
one key, which must be a digit. If 
a letter or other ciaracter is hit, it 
is ignored. The thsory here is that 
most typing errors occur by hitting 
keys near the correct one; and let- 
ters are often typed accidently in 
numerical input. 

10020 ZXS=INK=YS: IF (ZXS <* 
"O") OR {ZXS- "9") THEN 
10020 ELSE 2X=VAL (ZXS): 
RETURN 

In this case, the digit is returned 
as the variable 2X. and as tha 
string ZX$. 

Now we can elaborate this idea 
into the following subroutine, 
which inputs a njmber which it 
returns as ZZ. This can be used as 
a subroutine: instead of usinp) 
INKUr AS, use GOSUB 10030: 
AS = ZZ. 

In this subroutine, only digits, 
the decimal point, and the ENTER 
(or NEW LINE) key are acted on — 
everything else is regarded as a 
typing error, and ignored. 

10030 CR$=CHR$03) 

10040 2Z$="" 

10050 ZXS=rNKEYS:|FZX$ = " '* 

THEN 10050 ELSE IF ZX$ = CRS 

THEN ZZ=VAL tZZ$): RETURN 

10060 IF (ZX$*"9") OR (ZXS « 

".") OR (2XS='V"ITHEN 



10050 ELSE ZZ$=ZZ$+ZXS: 
PRINTZX$;:G0TO 10050. 

This subroutine works by filter- 
ing out alt the unwanted 
characters, and jumping the rest 

together into a string. The VAL 
function of Level II BASIC func- 
tions quite happily for strings, in- 
cluding decimal points — a point 
(pardon the pun) which not alt the 
books seem to be clear on. 

Of course, this only accom- 
modates positive input- The next 
subroutine accepts a negative 
sign as first character, allowing 
negative values input. Again, the 
subroutine returns ZZ; 

10030 CRS=CHR${13) 

10040 22$ = " " 

10045 ZXS = INKEYS:IF 

ZX$=" "THEN 10045 ELSE IF 

ZX$="-"THEN 

ZZS="-":PRINTZXS;:GOTO 

10051 ELSE GOTO 10051 

10050 ZXS=INKEYS: IF 
ZXS="' r THEN 10050 

10051 IF ZXS=CRS THEN 
ZZ=VAL (ZZS)rRETURN 

10060 IF (ZX$»'*9"J OR 
1ZXS«'\") OR (ZX$ = *7"JTHEN 
10050 ELSE 

ZZ$=ZZS+ZX$:PRINTZXS;: 
GOTO 10050 

This looks clumsy, but isn't 
really — it can keep up with fairly 
fast typing. Don't use it io your 
new word processor though. 

Tricks such as this have other 
applications too. The clumsy user 
who hits shift-backspace will be 
surprised to find all he has typed 
disappear. A simple problem — 
use a routine like those outlined to 
filter out the keys which are not to 
be acted on- 



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TfiS80/SVST€M 80 

Another help to the user is to 
force correct input by giving the 
proper format on the screen, and 
ignoring anything that doesn't fit. 
As an example, here is a 
subroutine to inputs a date. 

The format ../../.. is 
displayed, and as characters are 
input, they fill up the spaces. The 
day, and month, figures are 
checked for reasonableness as 
soon as they are complete. The 
disadvantage - single digit days 
and months must be given a 
leading zero. It isn't a lot more 
work to program around this; you 
need only check for a carriage 
return, or arrow key or whatever 
you choose to trigger a move to 
the next field. 

10 SCRN = 128 * where it all 

happens. 
20CLS 

30FMT$=" . ./. ./.." 
40 GOSUB 10000 
50 END 

55' - — 

9997' 

9998 ' date input subroutine. 

9999* 



10000 PRINT <gi SCRN, 

FMTS;:PRINT@SCRN.*'"; 

print format and go back to 

beginning of it. 
10002 ZZ$=- ":GOSUB 

10030:DAY =VAUZZ$) 
10004 IF (DAY « O) AND <DAY « 
32) THEN GOTO 10008 ' skip er- 
ror message. 

10006 PRINT @ SCRN+64.'*ER- 

ROR: incorrect day. Press any key 
to continue.": GOSUB 10040: 
PRINT <& SCRN+64. 

CHR$|31);:G0T0 10000 
10008 PRINT @ SCR+3." "; ' 
move to month field 
10010 ZZ$ = " ":GOSUB 

1 0030: MTH = VALIZZS) 
10012 IF (MTH - 1) AND {MTH - 
13) THEN GOTO 10016 ' skip 
error 

10014 PRINT @ SCRN + 64, "ER- 
ROR; incorrect rronth. Press any 
key to continue.": GOSUB 
10040: PRINT @ SCRN+64, 
CHRS(31»;:G0TC 10008 
10016 PRINT @ SCRN+6, 
" ";:ZZ$=" ":G0SUB 10030 
1 001 8 RETURN ' to main program 
calling 10000 



10019 ' next subroutine sets one 
digit (only!) and adds to ZZ$ 

10020 ZXS=INKEY$: IF {ZX$ « 
"0") OR <ZX$» "9") THEN 
1O020 ELSE 
ZZS=ZZS+ZXS:RETURN 

10029 ' this subroutine sets two 
digits, echos them. 

10030 FOR 1=1 TO 2:GOSUB 
10020: 

PRINTZX$;:NEXT:RETURN 
10040 IF INKEY$= " " THEN 

10040 ELSE RETURN : pause until 
key pressed. 

Of course, if you want to pro- 
cess or store the date, you need to 
pick up the day, month end year 
as they are input. 

This sounds a lot of trouble, and 
not very interesting. But it isn't 
really, and the results are well 
worthwhile. Besides, you need 
only write the code once to have it 
for use in any number of 
programs. 

This little demonstration looks 
fairly good — and it will look even 
better when you add a flashing 
cursor to it! 




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28 



BOOKS 



Sinclair 
book a 
good buy 

"Your Timex Sinclair 1000 And 
ZX81." 

Published by Sybex Publications, 
Author, Douglas Morgan Price 
$12.50. Reviewed by Tony Lewis. 

At first glance this book looks 
like a rewrite of the ZX81 manual. 
Further Inspection reveals that it is 
a lot more. Used in conjunction 
with the ZX81 manual it would be 
a very good guide to the beginner 
on the Timex 1000 or Sinclair 
2X81. 

There are five chapters and two 
appendices. Chapter one, "The 
Cast of Characters," goes 
through the initial setting up of the 
machine and what each pant does 
and what your role is. 

Chapter two, "The First Act: 
Enter Your Program," deals wfth 
the computer keyboard and the 
BASIC language used, 

Chapter three, "The Plot 
Thickens; A Short, Graphic, 
Course in BASIC," looks at the 
graphics capabilities of the Timex 
1000 and the commands needed 
to use them. 

Chapter four, "Take Five: 
Numbers on Your Computer," 
explains how the ZX81 or Timex 
1000 can be used as a calculator 
and how to generate bar graphs. 

Chapter five, "Words, Words. 
Words: Strings and String 
Functions on Your Computer," 
completes the book by explaining 
the use of strings and how you 
can "slice" them. 
Programs are used throughout the 
book to illustrate what is being 
covered in each chapter. 
Appendix: A gives a list of the 
BASIC vocabulary and what each 
word means. 

Appedix B gives a list of error 
codes used by the Timex 1000 
and Sinclair 2X81. 

Most programs in the book will 
run on the Sinclair ZX81 but since 
the Timex 10O0 has 2K of 
memory instead of the IK of its 
English counterparts, there are 
some programs that require 2K. 

In summary, in conjunction with 
the Sinclair manual this book 



could be very useful to the 
beginner as ft covers some areas 
that the manual overlooked. Value 
for money it has *o be a good buy. 



Useful 
Pascal 
work 



"From BASIC to Pascal" by 

Ronald W. Anderson, Pubfishgd 

by TAB Books inc. 310 Pages. 
$21,95. Reviewed by Gerrit 
Bahlman. 

If you are an exoerienced BASIC 
programmer who needs to be 
convinced that there is something 
in the structured beast, Pascal, 
then this book may be what you 
are looking for. By no means is it a 
beginners guide to Pascal. If offers 
a solid introduction which 
assumes a sophisticated 

comprehension of programming 
jargon and makes little concession 
to the novice. 

Notions such as the distinction 
between value and variable 
parameters oie not explained In a 
simple way, uti ising examples 
and diagrams — it is explained in a 
textual fashion that would leave 
the novice stranded. 

The book provides a very good 
comparative study between the 
two languages by programs 
presented in BASIC then Pascal, 
with explanations of their 
differences. The old much used 



recursion example of "Factorials" 
is presented as is a non-recursive 
version of the same exercise. 
While interesting, this is the only 
example of recursion cited and) 
once more fails to satisfy the need 
for more appropriate examples of 
this difficult concept. This is 
particularly true of the 
experienced BASIC programmer 
who has developed a mental 
attitude to non-recursive solution 
of problems which make recursion 
approaches difficult to grasp. 
The most attractive feature of 



Continued page 35 




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Distributors for:- 

BASIC PROGRAMMING ON THE BBC 
MICROCOMPUTER 

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Available from this magazine, computer stores and 

booksellers. 



29 



SOftD 



■aitMm. ii iit t mi ii wiw iw mm m iBMWuwiwHtiiHW 



PIPS III update — memory file pages 



By Peter Hyde 

Over ihe past few months, a 
number of SORD M23 users have 
bought and are using PIPS-HI, the 
latest release of SORD's Personal 
Information Processing System. In 
that time some discoveries have 
been made which will make the 
use of PIPS- III easier, and increase 
the power of the system. 

The first of these discoveries 
relates to getting the full use of 
the 128K of memory available in 
the M23. When PlPS-lll is loaded, 
most of this is occupied by the 
PIPS program itself and the 
memory work areas of PIPS which 
you know as the Master Buffer, 
Sub Buffer and Figure Buffer. 

The disk drives provide the 
permanent storage areas known 
as the Master File and Sub File. 
However, there is a temporary 
storage area known as the 
Memory File, which can hold three 
PlPS-lll pages. This large storage 
area in memory is useful when 
you want to work with several 
pages of data without having to 
access the disk. 

Transfer of the contents of 
these pages to and from the 
Master Buffer is almost 
instantaneous. Thus you can save 
a second or two by saving pages 
in the Memory File instead of the 
Master File or Sub File. 

Note; Because the pages are 
stored in Memory, their contents 
will be lost if you turn off the 
power. If you exit from PIPS, and 
then Te-enter without first 
powering off. the memory pages 
(like the Master Buffer) will be 
intact, except for the first one. 

Now let's* find out how to 
reference the three extra pages. 
This is by m eans of the P (Put) and 
G (Get) commands used for 
saving and retrieving pages on 
disk. 

Just as the statement: P;1 
saves the Master Buffer content in 
Master File page one, so: P;C1 
saves the Master. Buffer in the first 
Memory File. The codes C2 and 
C3 refer to the other two pages 
available. 

To retrieve the second page 
enter. G;C2 and press RETURN. 
Whatever is in that page will 
instantly appear in the Master 

30 



Buffer on the display screen. 

These memory pages cannot be 
referenced by PlPS-lll commands 
such as SORT, CS (Conditional 
Search). CAL (Calculate). L (List 
to Printer) or UPD (Update). These 
commands, and a few others, 
allow you to specify a range of 
pages on which the command will 
operate (e.g. L;S1,8 prints Sub- 
Files one to eight inclusive). 
However, you cannot specify 
SORT:C3...orCS:C1.2... 

The reason for this is that some 
of these commands actually use 
one or more of the Memory File 
pages for their own operations. 
For example, CS. UPD and CA use 
the first few line* of C 1 for storing 
the search conditions, SORT 
sometimes uses C2. And C3 will 
contain any automatic program 
you are executing (or have 
recently finisher executing). 

This imposes a limitation on 
your use of the Memory File. Treat 
the pages as a purely temporary 
storage area (like the Sub-Buffer! 
and save them on disk before you 
execute a conmand which may 
use them. Above all, DON'T use 
C3 in an automatic program! 
NOTE TO PIPS-II USERS: Yes. you 
have Memory File pages as well — 
7 of theml They are accessed by 
the commands. "PCF" and 
"GCF", and do not require "C" 
prefixes on the page number, e.g. 
PCF;6. 

Now that yoj have discovered 
the memory Files, there is one 
immediate application for them. 

Many users lave asked: "Is it 
possible to have PIPS remember 
my commands as I type them in so 
that I do not have to re-type them 
when creating an automatic 
program?" 

Short answsr: Yes. Memory 
page C3 can oe used to log all 
your commands as you type 
them. You can then edit them 
(using the ED command) and 
finally register your new 
Automatic Program. 

Use the following command 
sequence: 

0; TITLE This create s a blank 
page in the Master 
Buffer, with a title 

of your choice. 
<ESC> Press<ESC>key to 



P;C3 

SET; 
LOG=ON 



KIWVHmRM^MOTfifdHVMSMflyVWi^P 



end the 

command. 
Save the blank 
page in C3. 



Activate logging of 
your commands. 

issue any 

commands 

you wish to 

use in your 

programs, All commands are 

testing them remembered. 

as you go 

SET; 

L0G=OFF De-activate 
logging. 

G;C3 Get the list of 

commands. 

ED Edit your program. 

Pemember to put 
STOP on the end, 
and ensure you 
delete any mistakes 
you made in 
keying. 

AS;R;page Register your new 

number program. 

PlPS-lll is designed as a full 

system to give you the moono to 

do all normal business tasks as 
easily as possible. Automatic 
Programs extend the power of 
PIPS so that you can automate the 
jobs that you do. However, some 
task may be too complex for PlPS- 
lll to handle easily, or they may 
have requirements for speed or 
communications which PIPS 
cannot handle by itself. 

A special version of Basic called 
DBASIC 111 has been created to 
get over this obstacle. With 
DBASIC-III (the "D" stands lor 
"Docking") you can write 
programs in normal BASIC which 
process the date in PIPS pages in 
any manner you choose. 

Furthermore, you can compile 
your DBASIC program, store it on 
the PIPS program disk, and call it 
up *rorn within PlPS-lll using the 
command: DK#PR0G where 
PROG is the name of your 
program. 

Thus you can write your own 
custom routines to do such jobs 
as communications and data 
conversion to/from PlPS-lll pages. 
Anything you can do in SORD 
BASIC can now be done from 
within PlPS-lll itself. 



0€GINN€RS 



Getting 

loops 

straight 

Basic BASIC 6 

By GORDON FINDLAY 

Continuing a series on BASIC 
for complete beginners. 

Loops are so common in 
programming that almost all 
programming languages have 
special statements for coding 
them rapidly and easily. BASIC is 
no exception, and this installment 
will look at the FOR statement. 

Here is a simple program with a 
loop. Type it in, remembering to 
make any changes your machine 
expects (putting in LET, for 
example.): 

10 X = 1 

20 Y = X ■ X 

30 PRINT X; " ";Y 

40X = X+1 

50 IF X < = 20 THEN GOTO 20 

GO END 

Let's analyse it: lines 20 and 30 
do the real work — between them 
they calculate X * X; and print 
them out, separated by spaces. 
Line 10 makes this happen with X 
having a value of 1 at first; line 50 
makes it happen again and again 
until X becomes 20; and line 40 
makes sure the value of X 
increases by 1 each time. Lines 
1 0, 40, and 50 together make up 
the loop. 

Every loop has a "first" value, a 
"last" value, and an 

"increment", or step. In our 
program above, the "first" value 
is 1, the "last" value is 20, and 
the "increment" or step is 1. Try 
changing one or two of them, in 
lines 10, 40 or 50. 

There is a neater way: BASIC 
provides the FOR statement. 
Modify the program to look like 
this: 

1 FOR X = 1 TO 20 STEP 1 

20 Y = X • X 

30 PRINT X; " ";Y 

40 NEXT X 

60 END 



The FOR statement in line 10 
has the first, last and stepping 
values, and the NEXT X statement 
shows where the loop ends. 
These two act as a pair of brakes, 
as it were, enclosing the lines in 
the program which are repeated. 

In most machines, the STEP 1 
can be left out if the stepping 
value really is 1. So line 10 could 
become: 

10FORX= 1 TO 20 

Even if this is so, you must 
include the STEP phrase if the 
increase is by some other value. 
Change line 10 tc read 

10 FOR X = 1 TO 20 STEP 0.5 

Now X is increased by 0.5 each 
time round the loop, so more 
values are produced. 

Here is another program to try. 
Work out just what is produced, 
then try with a machine and see if 
you were right: 

10 FOR Y = 6 TO 25 STEP 0.25 
20 Z = 2 • Y 
30 W = 3 * Y 



40 PRINT Z, W 
50 NEXT Y 
60 END 

There are a few things to 
remember about FOR-loops to 
prevent disasters. Actually, these 
restrictions are true for any sort of 
loop, however constructed, ft is 
just that they are easier to express 
and more obviously dangerous in 
this case. 

Firstly, don't miss out the NEXT 
statement. If you do, the rest of 
the program will be included in the 
first interaction (first time round 
the loop), and then the program is 
finished. 

Secondly, name the correct 
variable in the NEXT statement. 
Some of the better versions of 
BASIC can make do without the 
variable at all, but even then you 
must be careful not to include the 
wrong one. 

It is often sensible to jump OUT 
of a FOR-loop, but it isn't very 
sensible to jump IN. If you do jump 
in, what is the value of the looping 
variable to be? Now I know it is 



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B€GINN€RS 

possible to fix things to make 
jumping in work, but there is 
always a better way. 

FOR-loops are often found 
nested. But if they are, the inner 
and outer loops must never cross. 
If you think about it, you should be 
able to see why — after all, what 
would the value of J be in line 70 
in this incorrect skeleton: 

10 FOR J = 1 TO 10 

20 

30 FORK = 10 TO 20 

40 

50 

60 NEXT J 

70 

80 NEXT K 

The program needs a value of K 
in line 70, but since K depends on 
J and line 65 is outside the J- loop, 
K cannot have a value . Th is is only 
one of the sort of things which 
can happen with crossed loops, 
and they are outlawed 
completely. 

One sure way to prevent nested 
FOR-loops from crossing is to be 
sure the NEXT statements come 
in the reverse order to their 
matching FORS. 

Here is an example of a program 
with correctly nested loops — all it 
does is prints out the 
multiplication tables: 

10 FOR I = 1 TO 10 

20 FOR J = 1 TO 10 

30K=I'J 

40 PRINT I, "x";J" = ";K 

50 NEXT J 

60 NEXT I 

70 END 

See how the J-loop is totally 
inside the l-loop, not crossing it. 
Now a job for you: modify this 
program to print a multiplication 
Table in the usual sauare form. 

From page 21 

transfer time differences cited 

would be far less apparent. The 

lesson here is that your peripherals 

and network should be on the same 

speed plane. A super-fast network 

running slow peripherals is wasted 

money. 

6 Can I change the machines I use 

on my network 

The user's dream is a network 
that any microcomputer can attach 
to. The reality is thai commerwal 
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manufacturers to specialise their 
Continued page 35 



32 



SINCLAIR 

Equation: 

Winning 

program 



"Equation" is for a Sinclair 
2X81 with 16K RAM, and unex- 
panded ROM. 

This is the winning program in 
"Bits Si Bytes" competition No. 1 . 
It is by Wayne Dobson, o/ Katamv 
High School, Hastings, and won 
him a Sinclair ZX81 supplied by 
David Roid Electronics. 

When "Equation" is run the 
name of the program and the 
writer's name are displayed. Then 
the program goes into an example 
showing movement keys, how to 
play, and the point scoring. That 
goes away and the computer 
simply displays in the middle of 
the screen, "Push G to PLAY". If 
G is not pushed then after a while 
that clears and an example of the 

high score being written yjp j 3 

shown. Another "Push G to 
PLAY' ' is displayed and if G is not 
pushed then the cycle starts 
again. 

Note, however, that if there is a 
high score it is displayed (just 
before the program's name) with 
the highest scorer and the holder's 
age. 

If G is pushed then the screen 
clears and you are asked to push 
either N for novice. I for 
Intermediate, or E for expert. 
Novice has a fixed height for the 
equations to come from and a 
slightly longer time to answer the 
question flines 2130 to 2140). In 
intermediate, the equations can 
come from 4 different heights (line 
3009) and the player has a shorter 
period to answer the equation. In 
expert, the player has a very short 
time to answer the equation and it 
can come from eight different 
heights. To stop people from 
working out a system the answer 
ship (your ship which is 
controllable) comes from different 
places. 

The game section — when playing 
the game the question will appear 
(addition or subtraction) and top. 
The player must then hold down 



the key (0 to 9) which answers 
the question until the scores at the 
top change and the answer is 
written up where it is to be 
displayed, Then the question 
starts moving end the player by 
moving the answer ship (an A at 
the bottom of :he screen! using 
keys 5 <1 TO THE LEFT), 8 (1 TO 
THE RIGHT) ar,d9 12 TO THE 
RIGHT) must position himself or 
herself ahead of the question and 
by using key (zero) must release 
the answer from the ship in time 
for it to move up the screen and 
connect (if possble) to the end of 
the question (scoring shows 
points and misses). 

Five misses is the end of the 
game and the highest scorer is 
allowed to put your name and age 

up. 

N.B. failure to answer the 
equation correction or push 
answer up at ship results a miss 
also keys must be securely held 
down, not Just taped. 

Wayne .has suggested the 
following amendments to his 
entry: 

Add - 
5Q03KHINI Al 0.21;C;ATQ,21;" " 
5005 PRINT AT 0.21:C;AT0.21;" " 

Change linos — 
2167 TO 2169 and repine© 2167 with the 
original 2 1 69 

3167 TO 3169 and replace 3:167 with the 
original 3 1 69 

4167 TO 4169 and rtpJflce 4-167 with the 
original 4 1 69 

The program 

1 & 10 Copyright, nane and writois name. 

date prog was written. 

30 sets high-score to wto. 

40 chocks to see if thjio is a high score, it 

POl jump to line 160. 

42 to 1 50 Displays high score, high scores 

holder, holders age. 

160 to 290 Displays frog's name, writer 
and month & year written. 

300 to 960 Draws a mock scmhwi and 
game as in the- pictures ol a novice game. 
970 10 1020 asks if you want to play. 

1 030 to 1 300 shows you whet to <Jo if you 
get the high score. 

1310 to 3340 asks if vou want to piny. 

1350 Loops back to 40- 

140O to 1630 asks you to choose a class 

(N. I. or El. 

2000 to ?460 is the rovice section. 

3000 to 3460 is trw intermediate soct*on. 

4000 to 4460 is the cupon section. 

5000 to 5160 is for a high score to> be 

written up. 

Variables 

A BS as a decimal nuTtber 

6 Score 

C Hi -Score 

E Score this turn 

F Height of e-Quau-on 

G Used to play Game 



H Column of answer ship 

I & J Used 1or loops 

K To givo a number deciding if the 

equation is + or - 

t High score holders age 

M First factor of equation 

N Second factor of equation 

O Sum of oquation 

Numbet of misses 

T Movement of equation in example 

7 Movement of -answoi in example 

AS 31 11 lino) ol spaces 

BS Used for answer to equation 

CS Hi Score holders name 

OS "4 +5=" for example 

ES Numbers for "A" movemoni in 

oxamplo 

F9 Number 9 for example 

Difficult linos to read 

2450 print at 8.0; AS : at 1 8,H; " " - one 

space. 

2460 go to 2005. 

3460 print at 8,0; AS : at 1 8.H: " » - one 

space. 

3460 go to 3005. 

4450 print at 8.0; AS; at. H; '* " — one 

space. 

4460 go to 4005. 

1460 lot 0=0, 



ia - = .■ - ■ ■_-'_■- : . 3ii — e ■■-• mb 

UBSC?V f.O'. IS'iJe 

. - ■■■ -. 
■ 

L a tf C - ■> tiii - - 1. 

~z phxmt *t- 0,i0, ■ i «-• 

>KP •■ -:.■-■-- 
ii Fr:? v ' flr - -.' --* <■ 

15 FR1MI' -IT ?. 1£ > • 

• a femur nr «..-..*. .--■ 

" IMT AT ?,-*;•'■ il*» *■" •- 

■ ■ • - • • ' 

63 PftXMT RT ••■:' ■ • ■ 

Tfl -^ITl BT " - - • ■ * 

. KSHT »r IQ,J," - . 

*»a wsiht sr ii. a;- .** ... , 

ii-j RfUtfl HT iSfii'-HSkB BY" 

s^c rcii.r «- i6,*.R( 

3.30 PR JUT *vr IS , CI "ACE "si, 

34o pop 1=0 to iSa ' 

3ro HOT I 

JM HW Ni-ME 

ibs prxnt «r a.» f "eouHrjgt(KBWR.T 



1M e=int mo 9 

aa» *>»X—T THP ? 

aiO PRH4T TSO 3 

-jo caim iri? ^ 

.:-*0 »^IMT T«D 3, 



.rue is. -o- 
TfiB za.-H- 

;tpb aa;-o 

, Iho 83; "I" 
iTSis aa 



' WfitSUHT IQUCOU 1 



fitiuaTiwi" 
' by urvue R r- 



n^o ps;mt or 3.191 

ioO PRJIlT DT 13,?: 

S7D PRINT THB 1 1. "NJOVCHBER 19B3 

aoe voo x»o to 3ob 
2C0 HEXT I 

iOO -EM CXBMPl-C 

aa p;?it«r -scom-B-.-RT t.n. ■■■-.. 

-SCORES" CRT O ._•*. I'lISi;;. -o 

330 Fttxtrr r« 1.0; 'BtoBi: t»ii> tu 

■HaO "T 1 ,iO. -flriSUER-" 

310 F=;i*r mi zi.o - j.u;.:j=tio»i by 
u r DtiB:-Q'* Jue?- 

D3B PRINT HT SB ,0: "LCFT-S' ,Hf S 
O . IS. "HIBUT i -? . — «i**' 

Soa p^iHT jr •,?;"lHtSH o to pla 

V 

37B PRIHI TRO 9, -UIlCH niKBO" 

399 t-xr ot-- i»a«" 

Sao CillMI MT 0,0.0* 
4QB KOU I-O TO a 
*IB NEXT Z 

tafl PBTMT Hr 1,87,0 
*2s »-c^ 1 -a to a 

*SB tET H-IO 

4KB po;Mt RT 18 .Hi* A ■" 

*70 POP I -1 TO * 
■1211 l-*-T a««"VS33" 

iSO IF liitl) r"V)" THEM (-HT M-M*9 

BBS JF EIIXI o-B" THfiN 1.KT M-H- S 

ae= =." till) s-a- then t_ET m-ii.; 

»1B PBIMT AT e,3.D« 
B3« EBIhT «T 13. M." R 

■so rc- j-e to s 
3+0 HKXT J 
330 HE'T 1 
|"; -=t XmXT 

u /a i.Ei 1 ■« 



33 



SINCLAIR 



-,- .. . . ■ ■ ,■ ■--■■■-■■■ 

■3-jO Jllr THEM PRINT AT Z4-1,H 



nats H.ET F«-"» 
aao IF ; il 

*a 



bo print *t z,n-a:#*» 

OIJ FRiNf HI U. t .D« 

eae let t-t*.i 
BDfl TDK I"0 TO B 
Bit a »ie*t j 
n-ja urt r«z-i 

DOB IF Tfal*. THEN COTQ SBC 

£70 PHIMT AT 11, Si"* POXNT3- 
osa pom i-o to 3o 

?IS..p5'int>t IW ' + ♦« "r"T 3 

'tiB PRINT BT 11.3;"* POINT*" 
7io for i-o ro so 
■730 HE XT 1 
■?*n i ff-imtp-T •.!*;•• **»- -.o: => 

'-789 print *r iijor-a points." 

7fr.U FOR I. a TD 3o 



: - 1 !! r.r -.- : 



ii 



at 0,3,*; 



4*5- 



-T ■ 



..... 



ip.n^ paint rnp o. -rt •novice " . -*n 

o i-;m l«mcd i*Tt -,3rt& b; *e-E;%p£ 

1KC3 IF 1NKCV*>- N - OR II^LVIr- I 
OH It.XEY.-~E- THEN OOTO 1665 

*.£»* SOTO 1603 

16B7 PRIHT RT S .0,H ■; Ra-.A.- *5 
^&ttf IP |H«V»»V TMEM OOTO JBC 

2 
iGAU IS 1HKCYI-' I" TMeNl QOTO 3BP 

193* X' JMKCY1- E THEN GOTO 400 



en •«»houic=» *» 
LET g, 



"?B0 PRINT RT 11.3: ".a POINTS" 
soo '■on x-e to ao 

aitO HSXT 1 

->i0 PRINT AT B.14,'* &•*■ ";«T E 

'aii ^nlMT »T 11.?; '1 POINT " 

eae row i-o to db 

■ 50 ■ . r ■- t I 

36e_PRll«T_ftT 3.1I.'9i<5- " - BT » 

'*7» PRINT AT ll,3f"0 POINTS' 
BSB "OR X-O TO 30 
-Bi> HBVT T 

Bed ffiivr »»t a.ia,- 9 4i-5« *",bt 
a, 13, - - 

IIO PRI-.T XT 11.3,-NISS 
9iO rCP S»C TO 30 

090 WBXT ; 

>.* Fa. kit «ir 0.13:" I -5 - 9" ; AT 

ft'o f ok :-e TO 3co 

,■ ■ - • 1 

■g=cri p'ifllt TO PLAY 

fc*NT > .1 ". PUBH TO Pi. 

icieo t -i i-a tc 303 

.. - INKBt •-'J" IHLN OOTO lis"- 

- •".■•'I- L3 >:■-"• 9-CCKO 

- ■ C-* 
:o3tf pwjhT e*r"M*»i.B 

L3EC ■•■ ■ u. CCM0»OTULor:c 

AT 7,aj"'V0U HfflVE THE 

- -^ - =I.IT»B VflUH" 

la&s ■ :■-'■ • •• il .a, "NMMt'- 

io »or. r-o to jiv 
UK f mr m .-:.«. -u". 
: .-;- ,-3. 'AVHB POO»C«a" 

'CR Ial TO 11 
: \ao p;p jio TO s 

: ice- --.::.■ > s 1 ;. 

liCJ FUXMT l»T ai .0. •■ 

1193 PRINT «T 11.6,-UnYWt POMOM E 

jaea ■ ;:«r at 13.»;-roe- 
;."".? rn;HT s» ai .0. 1 
isas ren^ijo to * 

brimt'at ai .0:1s 
iase por s-o Tp » 

1574 PWJMT AT 81 ,0; 

i.ifia nnifiT at 13,*;'"13" 
IB "on i»o to soa 

i->iaHR;ri PUSH O TO »UHV 

vs»o roR 1-0 to »oe 

1330 IF IHhtV|»-0" TMEH GOTO 1*-C 

a 

13*3 MCXT I 

13B0 -^TD 40 

1*31 PCI1 •••UMMCltl 

14 10 CI. 3 

L41B ttiT HO-0 

laaft (-ET fl-fl 

143P LET B-O 

1+60 v-cr B»Q 

1*73 IET OwO 
14S0 t.PT M»C 
1 i«3 UET X-O 

tsoo LBT JbD 

j.6 IO i.m k»B 
LH30 ler m.b 

!■«• VET 'i-i- 

tSBO LET o«a 

1BSD OfllNT "8COne-".BT d,u;-hi- 

»CORE»-:AT »,g*. -HISSES g" 

1S7B SHJNT AT 1,0, "SCOW THIS TL' 
BN»" mT IiIP-i "ANSUER«" 

asee print bt ai,o,-u«»«iMo.vou 

1f.UE OliL-V 3HB CHONCe" 

1-.9D PPX-HT BfT B.B/'C-OOSC VOOP C 
LMV 



aeao priiit bt a,o.fl» __ 

= 007 PRrMT AT 1 ,S7; "iAT io.m;" 

cOU i_bt KiiKT rRxoaai 

■fiBB ucr Mazrn* irhdhioi 

eeao let m-iki crno>*io* 

= U31 PBIHT RT 0.6;O;AT 0,»l,CiRT 

o.3i;d;ot 1 . 1&-E 

BOAe IF K-9 T-Ih LIT O-H.M 

QC9S0 IP K-O AND 0)>10 THEM OOTO 

4BS4 

2360 IF K=l THEN LET 0«M-M 

Si^iTP ir K»l AHP Ol -P TMtN -OOTO> » 

BBS 

SOBO UET M*3KT {P>IC*«13* -IO 

SaSfl PRXNT RT 1S.M, "»" 

5100 L.ET 2-1 

£110 IF KaB THfn PRINT HT (t.*;M; 

-♦■■;r*; "■'. 

aiae if k-i thin print at d,Z;m, 

£130 FOR I>3 TO- 3B 

B13B LET r-|r!!,".f.| 

illO IF B»»"- THEN NEXT I 
2160 Lf— ' n-CoDB P« OB 

2;6D IT RiO THEN UCT C »C • 1 
iie^ let j.e.E 

i;6&- XF O.C Tufftl LET C -0 

2ie? if hot n-o> <dih lbt t»-o»a 

siea ir a.c- tmeu lbt c>i 

£-69 PRINT «1T 1,10;E.AT O.O.fi.PT 

c.Ji.c.ar O.ii.O 
ii79 IF Q,<3 T1E^ OPTO SOtf".' 

S17B TF NOT A-Oi THEN OOTO 3*3© 

-=;ac p")iht **t ; . .- 11 

I19B =;■— — "1 TO J7 

aaoj ip k-b rp>EH priht hi b.z,** 

B210 IFK.l TMBN PRINT AT B.ZS" 
- H; - -'-,Nj " ■" 
=315 LET fi:K 
^.-iO LET H>M- . I'-t-.E". »■■■«"> • «!'■■ ■-' 

ii-i-i • i:nkev»*"|-» - 1 junen**^ — ■ 
i?2I IP H>93X T«P!< LET M«311 

c22H if M-. -O TMBN L.ET rt-O 
3383 IP HOT H.O THEN L-CT MO-1 
2339 IF INKBV*- '•" TMOiN LBT ■»-!«> 

S210 IP A-IO T"=H JOTO *3JO 

=;5H PK2NT RT 10 ","«" . _ 

E?e>e if MQ-i tmcn ««iht at is .a 



iZfS NE.VT Z 

aaes • ct aso. 1 

flSSO COTO Ji>00 

23iSO LET MT.17 

a.-.OS IF ".»& THEN PRINT AT 9 . i , 

£310 ir f.ml TMCH PRSIT ht t>.Z." 
■; m: "-'■fN* ~ ■" 

;--is uc \ : ~: - ; 

£33D if rti.iV T.iBH prim* *T 11TH 

.H: M ' 

23«© PRINT RT HT.MJO 

2Z-SO LET MT>«T-1 

ia&e If HT>-3 T«H GOTO a JOS 

ETT? IF MT-T AHD M-Z-4- IMEN L«tT 

! = !o 6 IP NT ^7 H»*D r»-2.3 THLh LET 

i;sa if KT"7 awo N»£«a then let 

eXgO IF MT = 7 HC.O N»Z«1 THEN LET 
sXlO^:^ "T-7 MHO "-~ Tilt" LET C« 

Illc TP MTa7 ««S HI Z-a TliCM .et 

--30*:> MT-7 "iWO H<-^-3 l"KH LET 

0-0 • J 
3440 LET B>B-e —- — »,■ 

2*43 PRINT AT l,ie,E;HI B,6.l> 

£^4* IF OlC THEN LET O-l 

B**C IF 8»C TMBN LBT C -B 

344.S IF O.-S T»«EH OOTO TIDCV 

VAZ BESS " S;o;«. ; mt *»,«>- •• 

"-ISSMSrraiMBefflTe.*. 

o pftiNT'ni e.o. h«;r«.a«;R»;R* 
300 7 PRINT RT 1,W; U ";AT iO,H, 

saoa i_er r«:nr m»«p**> »7 

3310 LET «3!NT IflHOiat 
£b£3 LET M=IMT IBMP.IO) 

3030 LET M = lt.r iRNP*lgl 
aOSO IF K-B TMEh LET 0-ll»N 

2%SX ir K ,° RNC- 0--10 THEN 3Of0 

-ypa CT 

3«r>(i ir K-a, TMEh LOT O-M-N 

3JB70 IF K»l "WD O.-B TMCN; OOTO 3 



■■■■-■ ' 

Bail LET M=M* iIHKEY|»"9"JtlI'«rr 
■"§--1 »I1MKEV#--«"J -IIHKBVB--B"! 
3^£1 IF H>-31 THEN LET M-31 
^^;j IF M«=0 TMENI LET M^W 
-■355 IF HOT HiS TMEH LET MO-1 

:"c IF IN-EV#."B" THEN LET h -ltS 

3840 TF R=10 THEN! OOTO 3300 
JO^O PRINT PIT lfl.M,"fl" 

piJF, E F HO»l TMEH PR3NT HT 10. P> 

33 '0 NlffxT- Z 
3aBO LET O-u-- 1 

33 OO GOTO 3l«0a 

33 OO LET HT-17* 

-JB5 XF K=0 THEN PRINT RT F , X; " 

3310 IF'Kil'THEH PRINT AT P.I;" 
33B& LET &«Z»1 

3'130 XF HT'S? THEM PRINT RT MT»i 

;?ie print at «T,h;0 

33 BO LET rCT-MiT-l „„ 

33BP XF MT.«P TUCH OOTO 3SOS 
■M>rO XF MT'P-l AMD H«IM THEN IE 
T EaBaS 

3380 Jr HT=r-l PWD tt»Z»3 THEN LC 

T CrC.l 

33-90 ZF HT.F-1 AND " -Z -J THEN LB 

T EaC+a 

34eO IF HTaF-1 AND H.I"J fnflN LaT 

T C:C»a 

34.1Q XF MTaF-1 RNO *1=Z THeil LET 

CiCtl 

ji.-. 1 :r -it ■"-; -no ns-Z-a Then ». 
kt o *a • 1 

34 30 IF MT-F-1 RNJO •• .■ - Z . b > -(■ n », 

CT 0=0*1 

3140 LET OiBtE 

3443 r>RiNT nr i,t6,t.UT i' > . if 

24.41 XF E>JC T:?C. L£T 3-. 

.". 1.:= IF BiC THEM LET C'D 
m(K — Z~" O > m* TME»J OOTO SCOO 
?i-47 "RIWT AT O.B1.C 

515P ra^MT A- S.O.UB.&T IB M ' 

Jlfiif i70T0 300-B 

4000 ~Z" •»*E''<Pfi-ir»« • 

<tac? — ET EiO 

10O6 PRIHT AT 5 .»?. HB ..:•■■*. Mt -'■■4 

^s: r*;a« 

4307 PRINT FIT 1.3*7;" " , HT 10,M;' 

■iffOB LET r=INT .HNDiOI'9 

JMP LET K-IMT IRIJU-J) 

iOJl) L=T I'-IIIT lRHD-il«) 

403O '—TTT H-1IJT iRNOalOi 

*O*0 Zr K=P THEN LET 0*I«tH _^__ 

Al>=0 IF Pi =0 RNC. C.-IO THEM UOTD 

ti~r ' 

4»bO IF K=l IMEM LLT 0=M-N 

•P76 ir «=1 AND O'.-O T«1£H OOTO 4 

4030 LEI M.Ii^T .RNSJl'-l . It 

4Buo r-BZiiT bt ia.ii; •*•>' 

ilCO LET 2=1 

41.10 3P P--0 TMEH PRINT «T P«Z{nj 

(ISO IF K=J THEN PRINT HT F^ZiM; 

ii.30 jwi 1=1 ro as 

4k35 LET B*-I'ME.'| 

f.lO IF D* = "" THEN NEXT I 

4l.se LET A-CODE of-aa 

1 IT IF O-O THEN i_ET 1 -•- - ' 
4-.OS LET D:B*E 
ilea IF D>C THEN LET CO 

iiGT IP H-OT H;0 THEN LBT 0-Ofl 

4TOO IF O-'C THEN LET O-S . 

*lo« F-AiNrr rt i.i«,e;~7 d,6;»;AiT 

o.3i;C;DT a r 3i.o 
4i7fl IF 01 .»5 THEH 00-ry b80Q 

417S IF MOT «-0 THEM GOTO 4-tSB 
4.130 PRSMT RT 1,37. A 

dlBO FOR i*l TO 37 

IF K.»0 TMEN PRINT RT P , Z; 



3000 Lcr n-wr ;KMOti^;«io 

5llO IF K.te TMEH PRINT MT T.Z.H. 
2i-£B N IF _ Kal TMEtl PRIHT AT F.ZlH; 

" -"; n; ■•-■*, 

31310 F?H 1-1 TO -r 
3135 LET BI-INKCVB 

J140 IP tlla " TUCH HOI 1 

3150 L£T •"• -CODE BB-aO 

Sl&O IF O^D TMEU LIT C-E.l 

;.?? let sse.e 

-•-.E-6 IF I«>C THEH LET C.U 

S1E7 IF HOT AaO TMEN LET O-OaX 

a ai C AT Q,31-D 

ilia "IF O ' -C TC'" OQTO Bt90O 
3173 IF NOT A«0 THEN OOTO 3*E>0 

31O0 PRINT AT i.a?:R 

3190 'C» 2"1 TO J7 

33aa IF K=B THEH RRINTT HT F..; 

3£XO If'kIi TMEN PRIM' RT F,=." 



4310 IF K-l THEN PRINT RT F.Z;" 

-;m; "-■';«; -a" 
*;;;y let O-h 

4SSO LET H-H- lINI\E-/»-"0 *l - t 1NKBY 

I»"3*'l HlNKEYi-"9"> -IINKBV»-"B"i 
331 IF HJ-33 THEN LET H-31 
-.;._.; IF Hi'a THgN LET H-O 
4»5 IF NOT HiO THEM LET MO » 1 

•Vl-30 I* INKE3Vl-."0" THEN LET Ralffl 

J-JiO IP R-IO TMEN OOTO -1390 

4USQ PRINT AJ 1B,H;' N ' 

*B0D ll " NO" 1 THEN PUIHT AT lO.Oi; 

4 a 7© NEXT Z 
43DO LCI 0-0»l 

crJUJ GOTO 40OO 

4300 LET MT=3,7 

4303 IF f.*0 THEM PRINT BT r,I'" 

- :M, "•-,«: "•" 

4310 IF Kil THEN PAINT RT F,Z;" 

•*vM; - --,m; "a— 

4sao let z-z-i 

433B ir rfT(17 TMEH PRINT RV Ml « 1 

,m; - ~ 

'"» POIWT at ht,n;0 

43BO LET HTaMT-li 

4 360 IP tfT>.F TMEN OOTO *3»fl 

43<"0 ;r HTsr-l RNO N-2*4 ThIIii k_a 
T B-C-B 

4300 ir MTsr-l UNO rt-Z*2 TNCN L.C 

4393~ IF MT=F-I HNO FI>Z>a TMEN LI 

4433 IP HT=P-1 RND M«I*1 TMEH LE 
l4l6 C XF KT.r-1 »NO H*Z TMCII LET 

4430 IF MT-F-1 RND M'aZ-a TMBN L 
ET O-Otl 

4430 IF MT"F-1 RND Mi-I*S TMEN L 
ET 0*0*1 



34 



SINCLAIR 



BOOKS 



iiffnmijniw"'i' 



44*11 LET Q.B + R 

4443 PRIMI AT 1 , IS ; K ; (*T 0.6;B 

C4t* IT BiC THEN LC7 & = 1 

Ui 1 - IF O'C TMCM LC C-D 

44*0 ir ©>-s t«cn ooto seee 

4*47 print bt a,ai;c 

443a BRjHT bt e,o:«i:«T IB -H; » 

i*(.0 SS»TO 4-OOB 

i91JB"L-| iiiNFU HIOM 5CORB»»» 
1MB TOW I«* TO 1B0 

saia next 1 

SD3B IW~NOT ami THBH OOTO 48 

bp*(9 prSHT AT ■.Bl-eOWOROTULCTTIO 

yeso print bt 7, a; 'vou houe tub 
MIUM SCORE"' 

snr>o print rt o,a; xnteo vour- 
■07* print rt aa.»;~NRMi ••; 

S3BG INPUT C» 

5C-BO PRINT C» „„__ „ 

eiao print bt 13, a-, hoc 
enu incut 1. 
013U VPIMT »T JJ.Tit 
313© FOR IbO TO Si> 

aiT>a CLft 

3103 GOTO -"O 



ftBrrWftVj^tfuyrt'Wv^ ^^i^W'*"i%w-W^i»w*v^rt^a*v^*A»rty' W*v^ -**v^ ■ 



From page 29 

the book is the depth to which 
particular "standard" program- 
ming problems are developed. 
One of the familiar tasks allotted 
to the programming student is an 
analysis of sort rates using various 
methods". This text provides a 
comparison program which will 
appear like mana from heaven to a 
student required to produce such 
a scheme. The sorts examined are 
the bubble sort, dried and slow!), 
insertion sort, inssrtion sort with 



APPl€ 

A tip for Apple users 



A reader, G. PORTENERS, of 
Paremata, offers this hint tQ 

Apple users 

You may be courting trouble if 
you are using the RENUMBER 
program of APPLE II PLUS 
SYSTEM MASTER (DOS version 
3.3 08/25/801. Try the following 
listing: 
tOQ-A'20 
20 R = B*20 
30 END 

Renumbering this by command & 
F= 5 results in: 
5Q = A'15 
15R = B*15 
25 END 

The factor 20 in lines 10 and 20 
assumes the value of the 
renumbered line 20. If, however, 
you write the expressions with the 

numerical factor first, i.e. Q = 20*A 

and R = 20 r B, all is well. I had this 
trouble in a program which used 240 
HPLOT N, SIN(A) *80 + 79. On 
renumbering the original line 80 



changed to 100 and so did factor 80 
to produce $IN(A)M0O. I have now 
changed the expression to 
80"SIN(A) and havs had no further 
trouble. 

From page 32 

networks. Having hooked you they 
have you. Having said that, there is 

on C3COp«. Most machines can be 

made to converse with limited 
flexibility through serial ports (this is 
fine for occasional data transfer but 
limited in every other way). The 
light is that there are a few networks 
coming in to production which 
allow far greater -flexibility, and this 
may be a significant purchasing 
factor. One networ< manufacturer, 
Omninet, was predicting a network 
capable of linking 23 different sorts 
of machine. There are limitations 
still in such an arrangement though. 

• Next month, Nick Smythe will 
look at networks which are 
available in New Zealand. 



binary search procedure, shell- 
metzner sort procedure and the 
quicksort procedure. The second 
point about these programs is that 
they are written so that the reader 
can utilise them as procedures in 
their own programs- 
There are a number of other 
programs which may also be of 
use to a new Pascal programmer 
who has as yet not built up a 
library of routines which might be 
needed. Linked list procedures, a 
label print routine, character 
conversion routines, a simple data 
base with editing procedures, and 
even a pseudo-random number 
generator. 

As a collector of esoteric 
routines that everyone writes as 
an exercise at one time or another 
I found the book immediately 
interesting, but. and there is 
almost alway a but . . . 

The layout of the text, which is 
blocky and unattractive, the lack 
of space and diagrams 
combined with the newsprint/ 
paperback quality of the materials 
used makes the book initially 
seem less than it actually is. 

In summary, it is a book which 
does not patronise the reader and 
expects that the reader has a 
modicum of experience in 
programming and has probably 

undergone a series of formal 
programming exercises in BASIC. 
It presents a library of common 
procedures that can be 
incorporated into any 

programming work without undue 
modification. Its presentation is 
not attractive but this is 
misleading. Perhaps the final point 
I can make is that I am pleased to 
have a copy — it will be useful! 



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COMPUTASHOP 
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Computashop is a low- 
cost way of reaching BITS & 
BYTES readers. 

You can save up to 55 per 
cent on usual advertising 
rates. 

Remember every BITS & 
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your computer business or 
product. 

Computashop, 
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Box 827, 
Christchurch, 



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advertisers 



■,: 



BBC 






^mWWWtWPW"™**"***"* 



dumw h hm ii— i— w 



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Beeb 

has Speed 



By Pip Forer 

Straining (he deadlines and the 
editors' nerves to the limits just to 
get a glimpse of the first 
"Computer Programme" before 
this draft article gets sent off. It 
seems that the BBC and IBM have 
at least one thing in common 
(apart from each having three 
initials). That common thread is 
the realisation that the greatest 
barrier to computer adoption is the 
newcomer's nervousness in the 
face of technology- Charlie 
Chaplin and a red rose and Chris 
Serle's matter-of-fact probings 
provide the same ingredient; 
reassurance. Whether you prefer 
the slick symbols of one or the 
personal approach of the other is a 
matter of personal taste. 

IBM also come into this column 
because this month we look 
hriefly at the basic model D Deeb 
and ask just how good it is in its 
native tongue, BASIC. There are 
two approaches we could take 
here. One is to catlogue the merits 
and problems of BBC BASIC. The 
other is to benchmark the BBC 
computer against various other 
machines. 

In general, BBC BASIC has been 
well received. Although its unique 
features will not transfer to other 
machines the combination of 
procedures, in-built assembler 
routines and powerful commands 
for handling Input/Output rather 
make up for that. VDU, OSWRCH 
and FX not only let you do things 
wefl within a BASIC program but 
make conversation with other 
machines that much easier. 

BBC BASIC has been well 
covered in reviews elsewhere so, 
for the moment, further 
discussion of that aspect is put 
asido, Instead we will return to 
benchmarks and (indirectly) IBM. 
What is a benchmark? It is a 
timed series of operations on a 
computer, usually used to 
compare the processing power of 
one machine against another. The 
task defined within the 
benchmark forms the basis of 



comparison. Thattaskcan be very 
simple (and pretty stupid). A 
common first benchmark is to run 
a null loop, i.e. 

10 (or i = 1 to 1000 
20 next I 

For clarity you usually insert a 
print statement at the top (Ready, 
Steady, Co) and another at the 
end announcing the programme 

has finished. Then if you have a 
stopwatch you settle back and 
time the task. 01 course, if you 
have a BBC you us the TIME 
command to do this for you. The 
command 

5 TIME « 

sets the clock ;ounter to zero 

and 

100 X =TIME;PRIN~ "BENCHMAHKEO 
TIME": X/100;' SECCNOS" 

prims out the final lapsed lime 

for thn tpst 

There are a few things to say 
about benchmarks. Firstly it is 
normal to run several on a single 
machine. This is because certain 
machines do sone operations 
more quickly than others. A 
second test might be to add 

15G0SUB 1000 
lOOO RETURN 

just to see how last subroutine 
calls work. A machine fast at null 
loops may be slow at subroutine 
calls (and one fast at both may be 
slow with rea'ly important 
instructions). The benchmarks 
usually therefore seek to test 
different aspects of a computer: 
setting varrabe- values, 

partitioning string variables, doing 
trigonometric functions, doing 
normal maths operations. A 
favourite is to fiid the prime 
numbers between 1 and 1000. 
Since disk drive access time is 
frequently a large part of running 
time many benchmarks also 
involve disk access time by 
reading and writng randomly 
generated values to disk files. 

Different publications publish 
and use different tenchmarks in 
their evaluative reviews. Three I 
know of are those from 
"Australian Personal Computer." 



"Interace Age" and "Byte". How 
does the BBC Computer behave 
on some of these? The "APC" of 
December carried a list of 49 
machines it had benchmarked. It 
used seven different programmes 
and averaged over these. They 
tested various aspects but had no 
disk access tests. The BBC came 
out as the second fastest. With a 
benchmark timing it ran through at 
14.6 seconds. This compared 
with the slowest on that list, the 
Texas Tl 99/4A with 78.2, the 
Apple 11+ with 30.4 and the IBM 
PC with 17.6. The significant 
update since then has been the 
release of the Apple He with a 
reportedly much-enhanced clock 
speed. A comparative benchmark 
with this machine would be 
interesting. 

Interested by the December 
benchmarks I ran the "Byte" 
benchmark used in a January, 
1982, review of the IBM PC on a 
BBC machine. The figures are 
given below. Thoy arc for 
resident, non-compiled BASIC in 
cither machine. The BBC machine 
figures are for a locally run 
benchmark, the IBM ones taken 
from "Byte," January. 1982, 
page 54. 
Benchmark IBM BBC 

1 Empty do loop 6.43 3.28 

2 Division 16.80 23.80 

3 Sutxoulino jump 12.4 5.34 

4 Substring (MID* I 23.0 T1.75 

5 Prime Number 1 90.0 Out o' 

■pKO 

I was unable to run the last 
benchmark fully since it requires a 
7000 element array. The BBC 
machine has not enough memory 
to cope with this so we had to 
omit it. Nonetheless, the figures 
are quite interesting. Why do the 
differences emerge between 
machines, both here and in the 
"APC" table? First, factors 
include the efficiency of the 
BASIC and the dock speed of the 
processor in the machine. The 
BBC machine outdistances some 
other early 6502 machines simply 
because its clock speed is cranked 
up to 2 megahertz. Some 
machines suffer because the 
BASIC interpreter they carry has 
been poorly tailored to the 
processor thoy use. One thing that 
seems to emerge from most of the 
comparisons is that, at least for 
8088 based 16-bit machines such 

37 



BBC 



r*v*fftt**mer * Ti<*jvft*f*™ 



as tine IBM PC you buy not for 
speed but for ease of handling a 
relatively large memory. Actual 
interpreted BASfC speeds suggest 
8/16 bit hybrids such as the 
8088-based machines are slower 
than a fast 8-bit machine but 
marginally faster than earlier 8-bit 
ones. 

A word of caution, however. 
The "APC" table listed three 
8088 based machines with 
reported speeds of 1 7.6. 20.9 and 
24.8 respectively. That is each 
was roughly 20 per cent faster 
than the next. Running other 
benchmarks on the same 
machines locally suggested that 
the slowest and fastest were 
equivalent while the middle 
machine was about 25 per cent 
adrift of these two. The 
conclusion: benchmarks are 
useful only as rough guides, and 
at that as rough guides only to 
speed. For many users that may 
be no guide at all. 

However, it is nice to have the 
power off a fast system if you need 
it. The BBC machine scores well 

on litis tor OAGIC application^;. 

However, one problem came 
straight to mind . . .it ran out of 
RAM. After all, benchmarks are 
designed to run on most machines 
and their demands should not be 
overly excessive (even if a 7000 
number array is quite large). 
Available memory is the Achilles 
heel of the BBC machine as first 
released. To see how this arises 
and how it can be countered by 
additional paged memory or a 
second processor read on in May. 



CLASSIFI€DS 

FOR SALE CHA.LENGER IP. 8K 
with Cassette Tape Recorder, 
software and manuals. 5 500. 
Contact Mrs J. Wood, Cambridge 
High School* 5415. 

WANTED Cash Flow, General 

Ledger accounting and farming 
software for SORD Ml 00 Ace. 
Contact J.R. Stevens. 6A Euclid 
Street. New Plymouth. Phone 
39-472. 



FOR SALE 

SURPLUS COMPUTER 
EQUIPMENT 
IBM model 2770 RJE station 
with 2213/2 printer and 2502 
card reader. 

DEC RK07 Disk Drives 28Mb 
(formatted) (two units) 
DEC RK61 1 Disk Controller 
DEC DZ11 A4B 16 line EIA 
controllers. 

APS C30 6800 based 

microcomputers (3 units) 

IBM and DEC equipment under 
maintenance agreements. 
Available now. 

Contact: The Director 

Computing Services 

Centre 

Victoria University 

Private Bag 

Wei ington 

Ter 721-000 Ext 703 



VIC 



From page 25 

then takes them from there to use 
them on a first in, first out basis. 

Our changes mean it doesn't use 
the buffer. It simply stores the Ns 
and Ys as we pushed 'hem and 
leaves them tbe'e in the buffer. 
Normally the VIC stores 10 
characters in.the buffer and if these 
aren't used, it ignores an>y extras. 

What we want to do is stop ihe 
VIC from storing any keys during 
the game. We can do this by 
poking the location that controls 
the number of characters stored. 
This location is 649. Try adding 



:P0KE 649.0 to line 20 and ;POKE 
649. 10 to line 220. That should 
solve the problem. 

Now if s your turn to take ovar 
the process of refining the program. 
A few suggestions - try making the 
bat a different colour from the ball; 
add another bat and make it a two 
player game. You could either play 
tennis, second bat on the left, or 
squash, second bat at the same 
end. 

If the game is too slow for yOu, 
change line 50 or perhaps allow lor a 
variable to be input and then used in 
the timing loop. The possibilities are 
endless. Have fun! 



CUSTOM WRITTEN 

PROGRAMS: 

FX702P, FX602P, System 

80/TRSSO, APPLEII, VIC20, 

and others. Other System 80 

software also available. Write 

with stamped self addressed 

envelope for information to: 

LINC 

36 Bruce Rd., 

Glenfield, 

Auckland 10. 



ZX81 users: I would be interested 
to swap software (educational 
software if possible). T. Daniell, 8 
John Street., Rangiora. 



Exidy Sorcerer equipment. 48K 

computer, display-disk, S-10O 
expansion, ROM Pacs, D/A- 
A/D, tape recorder, EPROM 
eraser, etc . Will sell any or all to 
first reasonable offer or best 
offer by 30/4/83. Telephone 
Wellington 723-494. 



ZX81 + 16K printer $350 Ph 
796-606 (Wellington). 

FOR SALE System 80 $800 0M0. 
16K. with sound lots of software. 
Phone Auckland 453-540. 

WANTED: 80-micro back issues. 
1980: Feb to May. 1981: Jan to 
June. Sept & Oct. Please sent 
issue nos & price to P. Clare, 8 
Norway St, Kelburn, Wellington, 

FOR SALE one 8K RAM pack, for 
the ZX81, includes reset button 
and power on LED $80. 

ZX81 FOR SALE ONLY $169wiin 

transformer and manual. Write 59 
Wesley Street, Kaiapoi. 

Casio FX-9O00P for sale $900. As 
advertised in February 83 issue. 
S. Jasper, Hilltop. Ohai, South- 
land. 

PROGRAMS for small businesS| 
and personal computers written or I 
modified to your specifications- 
Phone Paul Cull ChristchurchJ 
327-807. 



38 



CLUB CONTACTS 



.,.:> , ..--.-■ 



WMAMGAREI COMPUTER GROUP: Tom All-an. 
3 Mmou Rd. V/luMwjvtl. Phone 83-063 (w>. 
Meets every second Wednesday of the 
mciifi 11 NonNnid Conununitv CoUeee. 

NZ MICROCOMPUTER CLUB IMC. P.O. Box 
8210. Auckland. Tho montMy Meeting is 
head on Iho first Wednesday ot eacn month ai 

the VHP Clulwooms. Kaiel Av».. Mi Rosfc*. 

from 7.30pm. Visitors are alto welcome to 

the compute' workshop in tho clubtoomv 

lOum-Som, en the Saturday following thn 

above meetiiH). 

The foHcwirg uwf groups art paft of th* 

club. Ai meetings s"howi start 7.30pm at the 

VHF Oubroom. 

Other active user g*oups- wtthkt the dub eft: 
APPLE. CP/M. DREAM 6800. SMALL BUSINESS. 

KIM, LNW. SOftCEHER. 180? and 2650. 

Thoy can all be contacted at cl ub meetings or 

vie N2 microcomputer Club. P.O. Bon 6210. 

Auckland. 
APPLE USERS' GROUP: Biuco Given, 1 2 Irk-angi 

Rd,. One Troo Hill. Phono 667*720 (hi. 
ATARI MICROCOMPUTER USERS GROUP: Btlan 

o' Dean Vak.ii. Phono 8363 060 lh>. 

Meeting*: Second Tuesday. 
BBC USERS' GROUP: Dave ftetder. Phone 

770-630exi 518 (w). 
EUG BOARD USER GROUP: Steve Van Veen, flat 

S. Ill Maltose Rd. Ml Ac-skill, Auckland 4. 

Phono (09) 6*9-991 ml. 
BUSINESS USERS' GROUP: John Hawthorn. 1 1 

Soavtcw Rd. Rornutrt. Phono 642-714 im, 

876-189 iw). Meetings monthly. 
COMMODORE USERS' GROUP: Ooug Miller, 18 

Wetdone Ave., Glonliold. Phone 4.44-961 7 

lh|. 497081 <wl. Meetings: Tlv.d 

Wednesday. 
CPM USERS' GROUP: Kerry Koeperi. 2 670 

Oorrwitctn Rd.. Balmoral. Phono 69-5350 *ti». 

Meetings: M.co workshop. 
DREAM 6800 USERS: Polo- WMm ">0 KWcion 

St, New Lynn, Auckland, Phona 109) 8751 10 

(M, 
KIM USERS: Jo*m Mirn. 1A Norihooro Rd. 

TaAapun*. Phone (09) 4S7-8&2 Ihl 
LNW USERS: Ray James. Phone 109) 30-839 

Iwl, 585-587 <h), 
SINCLAIR USERS' GROUP: Ooug farmer. Phone 

667 689 W. Meeungs: Fou-th Wednesday. 
SORCeniR USERS' GROUP CNZI: Sehvyn Anew. 

Phone 491-012 Ihl. Meet*>g>: Micro 

wotiiinop. 
180? USERS' GROUP: Brien Conquer. Phono 

6S6-984 (h|. 

The above contact* can usually be found at 
N7 Microcomputer Cub Moot noji. or via P.O. 

Box 6210, Auckland, 

Olher Auckland-based groups: 

ACES (Auckland Comcuter Education Society): 
Pay Ciaske. 1 Ouftdas Pi-. Henderson. Phone 
836-9737 Off. 

CMUG iCombined M.cocom>pj:er Users' Group): 
This >s an assoc-atic-n ol Vtcioco-npuior 
Clubs. Groups, etc. formod to ca-orCinate 
activities and to Qlvo a combined voice on 
topics concerning sj| rnKFO men. 
Rootese ntation don a) Clubs and Croups b 
welcomed ;o: CMUG C- P.O. Box 6210. 
Auckland. 

EPSON HX20 USERS' GROUP. Contact: C.W 
NrQhy, 14 Domett Avenue. Eofcn. 
Auckland (Ansaphone. 774 268). 

HP41C USERS" GflCU? (Auduervl): O- 
Calculator Centre. P.O. ftp. 6044. Auckland: 
Grant Bvchansn. 790-328 IwjI Meets tn*d 
Wcdnoioay. 7pm. ai Conua Computerc. 
Great Sodth Rd., Eesom. 

NZ TRS80 MICROCOMPUTER CLUB: Ola! 
S«arsho>t. 203AGodley Rd . fnirangi. Phone 
8178698 (hi. Meets tint Tuesday, VKF 
Cl*jbrooms. Hazel Avo., Ml Roskttl. Auckland, 

OSI USERS' GROUP lAkl: Vlnca Martin-Smith. 
44 Murdoch Rd.. Grey Lynn, Auckland. 
Moots third Tuesday. VHF Ctubtooma, Hsiel 
Ave.. Mt fiosia. 

SYM«*00l INZ SYM USER * GROUP): J. 
Robertson, P.O Box 580. Manure**. Phone 
2S6-21B8 ihl. 



A.2..T.E .C: Etnan Mayo, Church Street. Katikau. 

Phone 4BO-326-. Member) use ad rricros and 

the dub has just bought a WW* erd. 
TAURANCA SINCLAIR COfVTUTcB CLUB: C. 

Ward. Secretary, P.O. Bo> 6037. Brookfiold. 

Tauranga. Phone 82 962 or 89-234. 
ATARI cMjBOO USER ClUB: Oevo B.own. P.O. 

Bok 60S3. Hamilton. Phone 1071) 54-692 

<ht. 
GISBORKE MICROPROCESSOR USERS' GROUP: 

Sluari Mullen -Merrick, P.O. Box 486, 

Gisborne. Phono 98-028. 
ELECTRIC APPLE USERS* GROUP. Noel 

Bmlcjcnan. P.O. Boi 3H)5. Fitzruy. Ntv* 

Ph/mouth- Phone 80-216 
TARANAKI MICRO COMPUTER SOCIETY: P.O. 

Box "7603. Bc5 Block. New Plymouth: Francs 

Slate.. Phono 84-514. 
HAWKE'S BAY MICBOCONPUTfR USERS' 

GROUP. Bob Brady, Prim* Phjrmacv. 

Plnma. Plaza. Napier. Phon* 439-016. 
VOTORolA USER GROUP: Harry Wiggint, 

(ZL2BFRI. P.O. Box 1718. Palmorston Norlh. 

Phono I063I8Z527 !h). 
MICRO AND PEOPLE IN S0CI6 1Y IMAPS): levin. 

meet* on second and fou-th Ihufs-Jav Of 

eech morith. 0. Cooe. 29 (rV-burgh Stieei. 

Levin. Phone 83 904. or W.Wrtnel. P.O. Box 

405. Lcvan. 
ATARI USERS' GROUP. tVelngton: Eddie 

NicklMs. Phone 731-024 (wl. P.O. 'Box 

1 601 1 . Meetings: lirst Wednesday of month. 

CENTRAL DISTRICTS COMPUTERS IN 

EDUCATION SOCIETY: Roiy Outlet. 4 John 

Shoot, Levin. 1069) 84-466 or Margaret 

Mofflan. 18 Slandon Stiwt. K.«o*i. 

Wolainflton. 104) 767-167. 
UPPER MUTT COMPUTER CLtO: Shane Ooyie. 
18 Holdworth Avenue. Upper Hutt. Phone 

278-545. An aa-macheie d«*b. 
BQC USER GROUP: Useis ol oth*r machifw* 

welcome ton Write P.O. Bok 'SO!. 

WeUington. or Phone 861-213. Wekrnion. 
0S60RNE USER GftOOft Dr Jb> Baxtaxa. &• »6 

Ghumco Street. Wollingtor 1. Phone 104) 

728 658. 
NZ SUPER BO USERS' GROUP: C/- PeBnwt 

Computers. 5 Oundoo PI., Chartwefl, 

Wellington 4. Phone 791-172. 
OHIO USERS* GROUP. We*ngtc*>. 

Stcretaryi'Irca-suftf: R.N. Mo*op. 658 

Awetea Street, Porirua 
WCLL1NGTON MICROCOMPUTING SOOETY 

INC.: P.O. Box 1681. WoBington. or BWH 

Patkin (h) 725-086. Mcot>gt ate held m 

Wang'a BUiUaX. 203 203 VYVL* Slfccl, on 

the 2nd Tuesday each month at 7.30pm. 
NELSON MICROCOMPUTER aUB: Dr Chrrs 

feltham. Marsden Valloy Rd, Nelson. Phone 

(054) 73-300 {hi. 
NELSON VIC USERS* GROUP; Peter Archer. P.O 

Box 860. Nrfsen. Phono (05*. 79-362 In). 
BLENHEIM COMPUTER CLUB: CM> night second 

Wednesday o* month, van Meyne4i. 

Secretary, P.O. Box 668. Phxva lh) 05-2O7 

Of (w) 87-834, 
CHRISTCHURCH ATARI US:ftS GROUP: 

Contact Edwin Brandt. Pborn 22e 222 lh), 

793 428 (w). 
CHRISTCHURCH "80 USERS* GROUP Dev4d 

Smith, p,0. Box 4118, Chrirctiutch. Phono 

63-111 IN. 
CHRISTCHURCH PEGASUS USERS' GROUP: 

Don Smith. S3 Farn/.rars 'd. Redwood. 

Cnnstchurch. Phone I03> 526-994 (hi, 

64-544 iwl, ZL3AFP. 
CHRISTCHURCH APPLE USERS' GROUP: Pawl 

Na U atei. C- P.O. Etox 1472. Coristchu'ch. 

Phono 79-6-100 Iw). 
OSl USERS' GROUP (CHI: Barry Long. 377 

Etttnngton St., Sgf«T*)n. Chfti-.-. 

Phone 384-560 Ihl. 

CHRISTCHURCH SINCLAIR USERS' GROUP: Mt 

J. Mitchell, Phone 385-141, P.O Bo. 

33-098. 
eHRISTCHUHCH COUMODOftE USERS* 

GROUP: John Kremef. 885 533 and Jorvi 

SpaffOw, Phone 886*039^ 
ASHBUnTO>JCO.V:PtJIEPSOCfEIi-:Mr J Cie*. 

52 Orucehckl Avenue- 



SOUTH CANTERBURY COMPUTERS' GROUP. 

Ceten (ot «■ machines for *fx8l to IBM34. 

Geoff MeCaughan. Phone Twnaiu 34-200 o- 

P.O. BOX 73. 
LEADING 60GE HOME COMPUTER CLUB- ElB'ne 

On. Leading Edge Computet s. P.O. Box 

2260. Ounedm. Phone 55 ?68 (w|. 
DUNEDlN VIC USERS' GROUP: Terry SHand. 24 

Bromnct Road, f#tf*w Phono (024] 

801-432. Meetings last Thursday ol month. 
DUNEDIN SORD USERS' GROUP; Terry Shond. 

Phono (0241 771-295 M, 881-432 (hj. 

NOTE: Clubs would appredaio a Clamped, 
stff>r*Wte«ed cnyoJooc with any wntien inquiry 
to them. 

NOTE: if your chiti or group la not itsled. drop 
a lino with the data's to: Club Contacts. BITS & 
BYTES. Box 827. Chrai crunch. The deadline lor 
additions end attetst-ons is tho second weekend 
Of tho month before iinj nt^nt 'iV'" 



N€UJ PRODUCTS 



A portable computer to rival the 
Osborne 1 is now on sole in New 
Zealand. 

Like T.he Osborne the Kaypro 1 1 
folds into a carrying case, 
although at 26 pounds it is two 
pounds or approximately one 
kilogram heavier than the 

Osborne, 

Tho Kaypro 1 1 luis x Z-80 
microprocessor, 64K RAM, a 76 
key detachable fcoyboard (with 
numeric keypad), an RS-232C in- 
terface port and Centronics 
parallel printer port and twin 5% 
inch floppy disk drives with 191 K 
of user memory on each. 

Probably the most significant 
difference from the Osborne is the 
screen, The Kaypro 1 1 has a 22.9 
cm (9 inch) screen (measured on 
the diagonal) displaying 80 
characters wide by 24 lines com- 
pared to the Osborne's 12.7 cm (5 
inch) screen. 

Also like the Osborne several 
software packages are included as 
standard in the Kaypro 11V 
$4690 price tag. These are CP/M 
disk operating system. S-BASIC 
(the "S" stands for structured), a 
word processing program called 
Select (and a disk called Teach 
which explains word processing 
to the first time user) and Pro- 
fitplan, a financial/calculation 
spreadsheet program again said to 
be oriented to the first time user. 

New Zealand agents for the 
Kaypro are President Computers 
of Auckland. We ■will have more 
on the Kayporo 1 1 in a later issue. 



39 



GLOSSARY 



BASIC: Boginnors' All purpose Symbolic 

InstrucOofl Code. The mut widely uwd, Hid 
easiest to loam. h>gh level programming 
language (a language with English-like 
instructions) for microcomputers. 
Binary: Tho system of counting in t's and Or's 

usedbyalld^iial computers. Ttw l's andO* 1 ? 

are represented In the computet by electrical 

pulses, either on or o". 
BJt: Binary digit. Each bit represents n ctwact-er 

in a binary number, that is either a 1 or 0. The 

number 7. initials 10 in Pinery and is :ac bits 
Boot: To toad tho operating system mio the 

computer from a disk or tope. Usually one of 

the first siepi m preparing the computer for 

use. 
Bug: An error in a program. 
Byte: Eight bits. A letter or number is usually 

repfoeoniod in a computer tiy a eeilos of eight 

bits called a byte and the compute' hand** 

these os one unit or "word". 
Character: Letters, numbers, symbols nd 

punctuation mirks «ecn of which has a 

specific mean«g in programming laoguawes. 
Chip: Ar> Integrated circuit etched on a tiny piece 

of silicon. A number of mieg'atefl circuits are 

used in computers. 

CPfM: A disk oparatingj system available for 
micrtKOrnputora using a particular 
microprocessor (that is the 8080 and 280 
base-d microcomputers such as the TRS 80 
and System 80). Sec also Disk Operating 
Systems. 

Cursor: A mark on a video that indicates where 

[ha next character will be shown, or where a 
change can next be made. 

Data: Amy information used by tho computer 
either i'O or Internal information. All internal 
Information is represented m btrtary. 

Dili: A flat, circular magnetic surface on which 
the computer can stoce and) retrieve data and 
programs. A flexible or (loppy disk is a- single 
8 incK nr 514 inch disk of flexible plastic 
ondosfd in an envelope. A nam disk is an 



assembly of several discs of hard plastic 
materia*!, mounted or* above another on the 
some spfnafe. The ierd disk holds up to 
hundreds of millions of byies. - while floppy 
disks cyp-cafly hold between 140-.000 and 
three million bytes. 

Disk drive: The mechanir.el device which rotates 
Ute cask and positions the read/write head so 
information can be retrieved or sant to the 
disk by the compute'. 

Disk operating system: A set of programs that 

operate ond control sne or more disk drives. 

S"0o CPi'M for one example. Other examples 
ate TRSDOS ion TRS SO) end DOS 3.3 (for 
Apples). 
Firmware: Programs fixed In a computer's ROM 

I Read Only Memtrvl: at compared to 

software, prograrrs held ouisride the 

computor. 
Hardware: The comparer itself and peripheral 

machines for storing, reading in and printing 

out information. 
Input: Any kind of infrrmation thai one enters 

into a computer. 
Interface: Any hard wore/ software systnm thai 

links a nWcrocompoicr and any other oevtce. 
K: The) number 1 024. Commonly refers to 105* 

bytos. Morn exception is capacity of 

ntMAaaj chips, whp<c k mean* tQ24 hits. 

KILOBYTE (or KJ: Represents 1024 bytes. For 
example 6K is 5120 bytos 16 x 10241. 

■s a B h fctl language* The binary code language 
that a computer can directly ""understand*' 

Megabyte Cor Mb): Rapotients a million bytes. 

Memory: The pat of the microcompuTer that 
stores Information and instructions. Each 
piece of information or instruction has a 
unique location assigned to it within a 
memorv. There it internal memory inside 0>e 
microcomputer itself, and external memory 
stored on a peripheral device such as disk s or 
tape. 

Mtofocomrxiter: A small computer rwisea on n 



microprocessor. 
Microprocessor: The central processing unit or 
"intelligent" part of a microcomputer. It is 

contained on o single chip of silicon and 

controta oil tho functions and calculations. 
Network: An interconnected group of computers 

or terminals linked together for specific 

CO mm unic ation t . 
Pascal: A high- level language that may 

eventually rival BASIC in popularity. 
PEEK: A command that examines a specific 

memory location and gives the operator the 

vnlue thore. 
Peripherals: All externa! input or output devices: 

printer, tetminol. drives etc. 
Pixel: Picture element. The point on o screen In 

graphics. 
POKE: A command that Inserts a valuo into a 

specific memory location. 

Program: A set or collection of instructions 

wmien in a particular programming langu-Jfte 

that cauaes a computer to carry out or 

execute n given operation. 
RAM: Rcndorn access memory . Any memorv into 

which you "read" or call up doto. or "writn" 

Ol enter information and instructions. 
RBrl statement: A remark statement in BASIC. Jt 

serves as a memo to programme*, and plays 

no Dot or the running program. 
ROM: Read only memory. Any memory n which 

information or instructions have been 

permanently fixed. 
Software: Any program* used to- operate a 

computer. 
System: A collection of hardware and software 

where the whole is greater that the sum of 

tho parts. 
Tape: Cassette tape used fo>r the storage of 

information and instructions (not music). 

Word: A group ol bits that am piocessad 
together by tho computer. Moat 
microcomputers use eight or 16 bit words. 



Casio's A ll-in-On e Personal Computer FX-9000P 

— S990.00 



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with battery backup. 

'0P2 twin floppy disks and RS323c interface. 

* MX82 Graphic Printer. * FP1 Mini Printer. 

All optional extras purchased with original order 
qualify for 25% discount off normal retail price. 




FX-9000P 



40 






Verbatim Datalife 3 flexible disks 
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We can give you a warranty this 
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All of our Datalife disks feature 
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Here is the news . 



The B.B.C. has arrived 

"Firstly the machine has been laid out with a clear growth 
path in mind: you can see how [he design has room for 
expansion. 

Secondly the machine as it stands is highly flexible. Il 
possesses the 'openness' of the Apple plug-it-in peripheral 
card philosophy, the screen software flexibility of the Atari 
400 and 800 machines and the teletext compatibility of Poly. 
Finally il seems to have taken all the little edges that most 
current machines possess, rounded them off and then French 
polished them." 

Dr. P. FORER in Bits and Bytes 
November, 1982 




B.B.C. Micro 

The face of things to come! 

FACTS THAT MAKE THE 
BBC BETTER 

•Price. .. is competitive... $1995 

• Good Colour essential for 

entertainment and in presenting 
information, you can highlight 
different areas at the same time. 

• The resolution of the screen allows 
640 dots x 256 dots which makes the 
BBC the best system available at this 
price. When making Graphs and 
curves, the better the resolution the 
clearer the curve. 

• Sound. . . four sound channels, three 
note generators, one noise generator. 
Full sound envelope control on sound 
channels. Is. adaptable to have a voice 
synthesizer fitted. The production of 
the sound does not stop or delay the 
running of the central process. 

• Basic. . . allows the use of 
PROCEDURES and REPEAT UNTIL 
loops, which give it the advantages of a 
structured language. 

• The BBC model B is the computer of 
the future. - - U is able to be hooked up 
to a second processor when necessary, 
the Z80 and 6502 already released. The 
BBC will never go out of date! A.16 Bit 
Processor to be released soon. 

it EDUCATION 

£ TRAINING COURSES AVAILABLE 
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Distributed by: 



Access Data Ltd Auckland Phone 686 578 



Branches in CHRISTCHURCH and WELLINGTON — and authorised dealers.