Skip to main content

Full text of "Syntax Magazine"

See other formats


Serving Timex-Sinclair 
Personal Computers 


VOL.4 NO.11 

ISSN 0273-2696 

NOV., 1983 


8K Programs 



to BASIC.4 

Memory Tester.5 

Pie Chart—Refinement.22 


2068 Programs 

Future History.8 

Book Review 

The Ins and Outs of the 
Timex TS/1000 & ZX81 ..6 

Classified Ads.22 


of Machines.14 

Dear Editor.12 

Machine Code 

Store & Recall.4 

Screen Reverse.8 

Screen Fill.8 

Character Table Start..8 

New Keyboards.14 

New Products & Services.3 


Rubbing It In.18 

Software Review 
Analogies, Logical 



Multiple Regression 


SQ-UP. 2 

Users' Groups.2 

Vendor Report.2 

ZX/TS Looks for 

Trapped Minds.18 

Index of Advertisers 

Byte-Back .21 

E-Z Key .19 

Gladstone .11 

Memotech .7 


To purchase the Timex Sinclair 2068 Computer see your local dealer 

Or mail this coupon to: Timex Computer Corporation, RO. Box 3138, 


Price Qty. Total 

Timex Sinclair 2068 Computer 


Timex Sinclair 2040 Printer 


Timex Sinclair 2050 Modem 


Timex Sinclair 2020 Program Recorder 


Timex Sinclair 2090 Command Sticks 

14.95 ea 

Please add $5 handling charge 


I enclose a check/money order for $_ 

Please charge my VISA® /MasterCard rM 
account no. 


Alphacom sells VP-42 plug-compatible, thermal 
printers. Beige. Call 800/227-6703 (800/632- 
7979 in CA). MC/VISA/AMEX or check or MO to 
ALPHACOM, POB 306, Half Moon Bay, CA 94019. 


Early shipments of TS2068s are selling well— 
Sears reordered 4000 units according to Dan 
Ross, Timex VP. A few units available at the 
Boston Computer Society TS Celebration disap¬ 
peared quickly. Buyers snapped up 1500's as 
well. Early tests suggest 1500 compatibility 
with most peripherals. Those confused by 16- 
32K internal memory will need some adaptor. 


Cartridge software for TS1000/1500 owners 
will be available by using a $19.95 T-Dock to 
feed buss signals through and connect the ROM 
plug-in—which uses chip-on-board technology. 


SQ-UP: In David Ornstein's premier 

issue article (SQ Winter 82 p. 29) 
Using Extra Keys on Big Keyboard, 
add a symbol A atop the D1 lead 
toward the right-hand edge of the 
page. The list of connections 
refers to this symbol. Also, the 
D3 (ANODE) legend applies to ZX80S, 
use D6 (ANODE) for ZX81s & TS1000S. 
Finally, change Jun.81 to Mar.81. 

Charles H. Bouley 


SQ closeout premium processing 
will continue to be slow. The book 
arrived in Harvard just before the 
BCS celebration & SYNTAX will pack 
and ship them early in Nov. Tapes 
will be ordered during that time 
and shipped after the books. Staff 
in circulation are changing subsc¬ 
riber records now. Labels will re¬ 
flect the change within two months. 
You will not miss any issues, but 
please renew when you receive your 
notice; cross-checking the records 
takes a long time. You will see 
the changed expiration date on your 
label when we alter the record. 

Memotech reports that only the 
RAM packs seem incompatible with 
the TS1500. No other problems 
reported so far. All plugins need 
extension cables to clear computer 
cables emerging from the back. Use 
your TS2040 printer, buy a flexible 
cable, or make an extender. 

TRS Color printers work badly 
with Memotech's RS232 interface. 
Said Fateh says Memotech will make 
refunds if the interface is not 
damaged. Memotech uses standard 
25-pin RS232 connectors; Radio 
Shack uses 4-pin DIN connectors and 
does not support the full standard. 

Memotech apparently will not 
introduce further new products for 
ZX/TS machines. As you know, they 
have designed their own computer, 
which will be introduced in the US. 

EZ-Loader contains a bug, says 
Ed Gidley. Kopak's Bob Schiller 
promises to provide the fix to all 
buyers of that package, as well as 
the printed manual to replace the 
computer-generated one supplied. By 
shifting manufacture in-house, 

Kopak hopes to improve quality 
control. Ed Gidley is sending the 
fix to SYNTAX—we'll pass it on. 

Timex 2040 printers have disc 
ceramic capacitors on the data 
lines. These cut noise, but slow 
buss timing. Cut one lead on these 
caps (usually 82p) to restore 
timing—and void your warranty. 
Early models use caps tack-soldered 
on the circuit side of the board; 
later ones are marked C4, C5 & C6. 

InfoWorld (V.5 N. 43 pp 57-58) 
says Budget Master 1000 contains no 
SAVE option—it's omitted from the 
program. SYNTAX called vendor HES 
(415/468-4111) who no longer offer 
the program in their catalog, but 
sell it on request. The reviewer 
feels it's a good program, you can 
repair the BASIC. HES software's 
Technical Support Coordinator says 
they quit supporting ZX/TS. 


Bladensburg, MD: Capitol Area 
Timex/Sinclair User's Group, P.0. 
Box 725, Bladensburg, MD 20710. 

(Jim Wallace: 301/699-8712) 

Bowie, MD: The Bowie Timex 
Computer Club, Lowell Demming, 

12611 Beechfern Lane, 

Bowie, MD 20715. 

Gainesville, FL: Timex-Sinclair 
User's Group, 3708 Newberry Road, 
Gainesville, FL 32607. 

Iowa City, IA: James Carroll, 1001 
Oakcrest #14, Iowa City, IA 52240 

Newport, RI: Ocean State T/S User 
Group, c/o Bob Dyl, 15 Kilburn CT., 
Newport, RI 02840, 401/849-3805. 



"HAM-HACKER"(TM) software includes: 
Morse Code 16K/2K practice w/ audio 
tone ($14.95), MINIMUF propagation 
($17.95), CE AMP for common emitter 
circuit design and test ($19.95). 
All 10% off till 15 Dec.83. Hawg 
Wild Software, POB 7668, Little 
Rock AR 72217. 

Four Hewson Consultants programs, 3 
for Spectrum, and ZX/TS PUCKMAN 16K 
will be available from Hawg Wild 
for $15.95+$2 P&H ea. Backgammon, 
Countries of the World, and Night- 
flite are offered as compatible 
with your TS2068, but the Hawg is 
hedging—delivery may be delayed. 

"POSTMASTER" in MC accepts address 
files & 2 user-defined codes, up to 
75 records/tape. Quick search for 
fast retrieval. Review on screen 
or print to TS2040—$9.95 + $1 P&H 
TOOLKIT moves RAMTOP, prints bytes 
free, renumbers BASIC, or assembles 
MC using ZX/TS dec codes—$7.95 PPD 
GENEALOGY stores a four-generation 
family tree on one side of tape and 
prints to TS2040—$6.95 PPD. Z- 
WEST, POB 2411, Vista, CA 92083. 

Computer literacy programs to teach 
programming concepts through games. 
Gridlock uses graphs, cooordinates, 
plots, and screen display. Turning 
the Truth Tables exercises logical 
thought via AND/OR, greater, equal, 
lesser, 0/1, and IF. Snake Eyes 
demonstrates random numbers and 
chance with histograms and classic 
casino games. All use graphic or 
text game format—$14.95 ea. Basic 
BASIC covers display, input, loops, 
moving graphics, and subroutines. 
User then builds upon the skeleton 
program to create an action game— 
$17.95. 2-BIT SOFTWARE, POB 2036, 
Del Mar, CA 92014. 619/481-3629. 

Software in package deals qualifies 
for Timex's buy 2, get 2 free deal. 
Phoenix Enterprises, 1780 N. DuPont 
Hwy., No. 17, Dover, DE 19901. 

UK acoustic modem connects to MIC & 
EAR jacks for simplex transmission 
of programs, blocks of memory, or 
screen contents between ZX/TS and 
Spectrum. Uses 5mA from computer 
power and UK modem frequencies—2 
cycles of 1650Hz for mark and 2 of 
2475Hz for space. No start or stop 
bits; byte only. Max. message is 
15 Kbytes. Menu-driven software. 
£48 Micro-Myte Communications Ltd., 
Polo House, 27 Prince St., Bristol 
1, UK. Tel. (0272)299373. 

Contact Lens overlay for your ZX/TS 
membrane keyboards, rectangular, 
bevel-edge holes to guide fingers 
to keys. Adhesive backing. $7.95 
PPD 30-day refund. Warren Imports 
Group, 81 Brookmill Blvd., Unit 80, 
Agincourt, ON Canada MlW 2L5. 

Programmer's Market organizes 500 
software publishers and marketers 
for your original programs. Lists 
contacts, requirements, payment 
terms, and contract work available. 
Organized by type of computer (31 
Timex entries), type of software, & 
alphabetically. Writer's Digest 
Books, 9933 Alliance Rd. Cincinnati 
OH 45242. $16.95+$1.50 P&H. Visa 

or MC call 800/543-4644. 

Two 16K, printer-compatible, filing 
packages by Russell Brewer. Rapid 
File—menu-driven edit, search, in¬ 
sert, & delete—machine code file 
handling and packed files. Rapid 
Finance lets user set up 19 accts, 
enter by date, account, amount, & 
optional comments for up to 500 en¬ 
tries. $10.95 ea, PPD in US. 26630 
Mill Rd., Frazeysburg, OH 43822. 

Power Squeezer drives up to 256 BSR 
controllers from your ZX/TS (1500's 
included) or allows 20 devices with 
software clock-calendar and 7-day 
program. Updates every minute. 
Cassette, transmitter & manual for 
$79.95 PPD (UPS Blue or Priority 
Mail). Avail. Dec.83, Advance 
orders to Goldwater Mfg. Co., POB 
1715, Sandy, UT 84091. 


IRA Organizer to record retirement 
fund transactions. Store date, de¬ 
posits, withdrawals and interest. 
Seven-option menu: enter, correct, 
save, print, or display all, one or 
summary. On tape for 8K R0M/16K. 
$16.50 from John B. Carson, Jr., 
11200 Lockwood Drive, Number 307, 
Silver Spring, MD 20901. 

MLVSS, SVI, TSS, Total Solids) menu 
driven, printer compatible. $24.95 
each. Labsoft, 1707 King St., 
Jacksonville, FL 32204. 

Data acquisition module multiplexes 
14-channels via an integrating A/D 
to ZX/TS (incl. 1500) to measure V 
ac/dc, dc I, temp., or frequency. 
Reasonable ranges, but not industr¬ 
ial standard values. Allows random 
scan under program control. ROM 
software at addresses 15360-16383 
called by USR. Results converted 
to quantity measured & returned in 
floating point for computation. 

User sets conversion time/channel 
to trade time (1-5 sec), error & 
noise rejection. No calibration 
needed. Works in IK RAM, plugs on 
edge connector and extends buss. 
Model 2900-Z, $89 PPD. MC/VISA 
Occam Research, Inc., POB 1055, 
Trumansburg, NY 14866. 

RPNZL programming system uses full¬ 
screen text editor for FORTH-like, 
stack-oriented syntax. Load/ save 
12 times faster than ZX/TS BASIC & 
verify. Integer only, full string 
handling, resident monitor, plus 
TS2040 support. Language tape, 
editor/compiler, linker, & manual. 
Requires 16K RAM. $29.95+1.50 P&H. 
The Golden Stair, 141A Dore Street, 
San Francisco, CA 94103. 

Peel & stick keys of resilient foam 
with characters & graphics in black 
and shifted characters in red. For 
ZX/TS keyboards to give soft feel. 
No keywords or functions on these. 
$5.95 PPD. E. H. Enterprises, 

POB 4068, Little Rock, AR 72214. 


Adding BASIC commands can be 
accomplished by locating machine 
language subroutines in RAM that is 
safe from NEW and LOAD. Two ideal 
places are above RAMTOP or below 
address 16384, such as in Hunter's 
NVM. You call the commands with 
USR; either in immediate mode or 
from within a program. This example 
gives details for placing routines 
above RAMTOP or in the Hunter NVM. 

STORE transfers a screen image 
(display file) above RAMTOP to be 
re-displayed by the RECALL command. 

Enter listing one exactly as 
shown. Notice that you enter hex 
codes directly into the REM at line 
one. Line 6 translates these to 
decimal codes as it POKES your 
program to the chosen RAM area. 


SAVE the program by entering 
RUN. Now when you LOAD the tape, 
the program RUNS and transfers the 
routines to memory automatically. 

STORE by using RAND USR 30000, 
won't work in immediate mode since 
CLS always follows immediate entry. 

After loading the routines in 
upper memory, RAMTOP is lowered to 
30000, thereby protecting them from 
NEW and LOAD. To shield the STOREd 
screen from NEW and LOAD, relocate 
RAMTOP to 29000: POKE 16388,72; 
POKE 16389,113. 

To change listing one for use 
with the Hunter NVM located at 8K, 
delete lines 9 and 10 and change 


line 4 to LET L=8192. New calls 
are STORE, RAND USR 8192, and 

Len Harmon, Metairie, LA 



2A0C40 STOR 




LD DE,7148 



LD BC,0318 








214871 RACL 

LD HL,7148 


ED5B0C4 0 




LD BC,0318 








My ZX/TS's erratic behavior 
when it ran big programs made me 
suspect memory problems. I wrote a 
BASIC program to perform a simple 
check of memory above the first IK 
of RAM. It found two bytes where a 
bit was dropped; I fixed the 16K 
RAM by replacing one chip. This 
program can help if you suspect a 
memory problem. 

MEMTST writes all zeroes into a 
byte, confirms that all bits equal 
zero by reading the byte, writes 
all ones in the byte, confirms that 
bits are all ones by re-reading the 
byte, then moves to the next byte. 
Lines 70 & 90 record errors. 

To use MEMTST, first do the 
following without line numbers: 

POKE 16388,0 
POKE 16389,68 

These POKES set RAMTOP so the stack 
resides in the first K of RAM. (So 
MEMTST will not destroy the machine 
stack.) Type in MEMTST exactly as 
shown. In line 20, spell out words 
except REM. If you SAVE MEMTST, 
set RAMTOP before you LOAD it. 

Run MEMTST. If all goes well, 
about 4.5 minutes later "END" will 
appear on the screen. If numbers 
show up, you have a memory problem. 

Each line represents one bad 
memory location. On each line the 
first number shows the address of 
the erring location. The second 
number contains the code read from 
the location. The third number is 
the code written to the location. 

To find which bits are bad in 
a location, convert codes first to 
hex and then to binary. Read the 
second number from a line on the 
screen and find it under the code 
column in appendix A of the BASIC 
manual supplied with your computer. 
Beside the code you will find a 
two-digit number in the hex column. 
Interpret each digit according to 

the following 






































For the two hex digits you'll have 
8 bits. Thus, code 127 means hex 
digits 7F and binary, 01111111. In 
this example, if the 3rd number was 
255, the leftmost bit is in error. 
(Zero gives all 0's; 255, all l's.) 

If the screen fills with errors 
when you RUN the program, push CONT 
to see more errors. Repeat until 
you see "END" displayed. RUN the 
program several times; some errors 
show up only on repeated /trials. 

Ron Charlton, Paducah, KY 




The Ins & Outs of the 
Timex TS/1000 & ZX81 


Don Thomasson 


Melbourne House, Dept. 
347 Reedwood Drive 
Nashville, TN 37217 



$12.95 (Softcover, 101 


"At last a hardware reference 
manual which covers all aspects of 
the TS 1000!", reads the Melbourne 
House ad for "Ins and Outs ". 

While the book provides a number of 
interesting tips and schematics, it 
falls far short of comprehensive 
coverage. Thomasson's book offers 
clearly printed pages and contains 
15 circuit diagrams and 9 other 
illustrations. Three sections 
organize the book: Internals, the 
External Interface, and Externals. 
In addition, two very short 
appendices present some simple 
BASIC and MC driver programs. 

Internals supposedly tells us 
all about the ULA (uncommitted 
logic array) or "workhorse chip." 
However, only 2 pages describe the 
general function of the chip before 
Thomasson (figuratively) throws up 
his hands over the "Machiavellian" 
complexities of the ZX's innards. 
Here he warns us again (the first 
several warnings come in the third 
paragraph of the introduction): 
"very little change is permissible" 
in the insides of our computers. 
This theme appears throughout the 
book: he tells us more about what 
we can't do than what we can do. 

After a disappointing look at 
the ULA, Thomasson delves into the 
TS's use of IN and OUT ports (FB, 
FD, FE and FF) for tape loading and 
keyboard, and briefly describes the 
video display. He gives simple 
memory expansion schemes, as well 
as a basic big keyboard layout. 

"The External Interface" pages 
describe the ZX/TS busses (internal 
and external) and investigate what 
those edge connector pins really 
do. Again we get a very brief view 

of the various functions available 
and Thomasson dismisses some out of 
hand as unusable. For example, for 
Ml (machine cycle one) he says "no 
external use can be envisaged". In 
fact, many add-on memories need Ml 
to decode addresses above 32K. 

In the last section Thomasson 
addresses external add-ons: The 
chapter starts with a basic power 
supply and then moves to a simple, 
but somewhat expensive, 16K RAM. 
But, it appears that some control 
lines may be missing in the plans. 
(For instance, one 16K RAM plan 
shows a WR line, but no RD or 
MREQ—this memory probably works 
by itself, but could cause problems 
when used with other peripherals.) 
Thomasson discusses basic I/O ports 
using Z80 PIO and 8255 PPI chips, 
though again, very briefly. 

Next, Thomasson introduces a 
Centronics style printer interface, 
potentially the most valuable part 
of the book. His design (software 
and hardware) should provide you a 
solid interface which even supports 
LLIST, LPRINT and COPY. Like Ener- 
Z's Report Generator board, Thomas¬ 
son overlays ROM print routines at 
0851H with his code. The chapter 
ends with examples of basic A/D and 
D/A converters, a sound generator, 
and 13 pages of BASIC program and 
explanation of a simulation of a 
model railroad system, not the real 
world control system advertised. 

This book contains useful tips 
& hints, and the printer interface 
concept seems sound. I give this 
book 6 out of 10, as it doesn't 
live up to its claims. 

Paul J. Donnelly, Centerport, NY 

Manual references mean the Sinclair 
UK manual—with its differences. 
Display timing (p.13) applies to 
50Hz systems. In the British way, 
you'll find some obtuse comments, 
but display and keyboard operations 
are clear, if brief. Five lines of 
text hint at how the simulator gets 
replaced in a control loop—KO. 


The Complete Range 

Fiiteen months ago Memotech developed the first 64K Memopak, designed to maximise the capabilities of the Sinclair 
ZX81. Since then, using the ZX81 as a starting point, we've gone on to produce a comprehensive range of Memopaks. 
adding 16K and 32K memory expansions, utilities packages comprising a Word Processor, Z80 Assembler and 
Spreadsheet Analysis, plus Communication Interfaces, High Resolution Graphics and a professional quality Keyboard. 
To complete our range of Timex add-ons, we are now introducing the MEMOPAK RS232 Serial Interface. 

RS232 Interface 

The RS232 is an all-purpose interface 
which allows the Timex not only to 
output to suitable serial printers, but 
can link up with numerous types of 
peripheral or even other processors. 

The Interface has two main modes of 
operation: BASIC mode allows you to 
use the range of functions supplied in 
the RS232 EPROM within an ordinary 
BASIC program, and TERMINAL mode 
allows you to use your Timex as a 
terminal to another processor. 

The EPROM functions offered permit 
the user to send, receive and convert 
bytes between Z80 code and ASCII, as 
well as check the status of numerous 
control flags. Received or transmitted 
data can appear simultaneously on the 
screen, and received data may be 
printed simultaneously. 

$79.95 cable $19.95 

Memopak Centronics 

The BASIC commands LPRINT, 

LLIST and COPY are used to print on 
any CENTRONICS type printer. All 
ASCII characters are generated and 
translation takes place automatically 
within the pack. Reverse capitals give 
lower case. Additional facilities allow 


Text is first arranged in 32 character 
lines for the screen with comprehensive 
editing facilities. On output the user 
simply chooses the line length required 
for printing and the system does the 
rest. Used with the Memopak 
Centronics Interface, the Word 
Processor makes available printout with 
80 character lines, upper and lower 
case and single and double size 
characters. i 




For those setting 
out on the road to real 
computing, these packs 
transform the Timex from 
a toy to a powerful computer. 

Data storage, extended program¬ 
ming and complex displays all become 
feasible. Further details available on request. 
16K Memopak $39.95 
32K Memopak $79.95 
64K Memopak $119.95 

high resolution printing. 

$59.95 cable $19.95 

Memopak HRG 

This pack breaks down the constraints 
imposed by operating at the Z80 
character level and allows high 
definition displays to be generated. All 
248 x 192 individual pixels can be 
controlled using simple commands, and 
the built in software enables the user to 
work interactively at the dot, line, 
character, block and page levels. 



The screen display behaves as a 
'window' on a large sheet of paper on 
which a table of numbers is laid out. 
The maximum size of the table is 
determined by the memory capacity, 
and with a Memopak 64K a table of up 
to 7000 numbers with up to 250 rows or 
99 columns can be specified. 


Z80 Assembler 

The Assembler allows 
you first to code and 
edit a source program in 
the Z80 language, and 
then assemble it into 
machine code. You can 
now write flexible and 
economic programs. 

The Editor mode 
allows you to code 
directly in the right 
format, manipulate 
inidividual lines and 
control the exact placing 
of source and machine 
code. Routines may be 
merged or listed (even 
to a commercial printer 
using our Centronics 
Interface). The 
assembler mode handles 
all standard Z80 
mnemonics, numbers in 
hex or decimal, 
comments and user- 
selected tables. 


Memotech Keyboard 

The Memotech plug-in Keyboard plus buffer pack takes 
the effort out of data entry for Timex users. The Keyboard 
has a light professional touch and is housed in an elegant 
aluminum case. The simple plug-in system means that you 
are not obliged to open up your Timex, use a soldering 
iron or invalidate your Timex warranty. 

Keyboard Buffer Pak , 

The Buffer Pak performs a "housekeeping" function for the 
Keyboard, interfacing directly with the port of your Timex. 

$79.95 — (keyboard & buffer included ) 

Note ! All Memotech products carry a 6 mo. warranty. 
80 column dot matrix printer packages available at a 
substantial savings from Memotech. 

Order at no risk (10 day money-back guarantee ) : Call 1-617-449-6614. Or send your 
name, address, phone number and a check/money order/Visa or MasterCard number with expiration 
date to: Memotech Direct Sales Division, 99 Cabot Street, Needham, MA 02194. 

Shipping/Handling $4.95 


In Jan. 1981, SYNTAX published 
LIGHTS OF THE CITY for the recently 
announced (and long-awaited) 8K ROM 
for the ZX80—it would be 10 months 
before ZX81's were announced in the 
US. For kicks, we updated CITY for 
the TS2068—just as it was updated 
from a 1978 version for the PET. 

Using simple graphics, this 
program generates an ever-changing 
video pattern like a growing city. 
To use, type RUN, then enter a 
PAUSE time (number of TV frames to 
display between moves). Depress P 
to run at top speed. 

Variables x & y define line & 
column of the PRINT position. The 
program selects a random direction 
(up, down, right, or left), changes 
the current position accordingly, & 
prints a character there. Display 
freezes for z frames, then changes. 

All the original program lines 
remain exactly, but we modified the 
program to add color. Lines 17 and 
107 are totally new; line 5 shows a 
new INPUT prompt; line 100 includes 
an INK command inserted before c$. 

You can run the old program on 
any ZX/TS with 8K of ROM: to see 
the original effect put your ZX/TS 
in FAST. Run this on your TS2068. 


This "souped-up" version of my 
SYNCWARS game runs in SLOW mode (no 
screen flashes or jitter) and shows 
more spectacular displays. Other¬ 
wise, the program plays just as the 
2K version, published in SQ Vol. 2 
No. 1. This version uses about 6K 
of memory, so you need a RAM pack. 
First, enter the loader program of 
Listing 1. Check to see that it is 
exactly as listed, RUN the loader 
and input the decimal listing shown 
after listing 1. Syntactic Sum now 
gives 18889, and the top 5 program 
lines should look just like lines 
1-5 of listing 2, the game program. 
Next enter lines 10-1590 of listing 
2, replacing the MC loader. 

To SAVE the program to tape, 
enter RUN 180. Line 180 shortens 
SAVE/LOAD time by compressing the 
display file. To play after you 
SAVE—BREAK, POKE 16389,128 and 
RUN. When LOADing, this byte will 
already be set correctly. 

Do not make any changes in 
lines 1-5, doing so will result in 
a crash. You can employ this trick 
to discourage people from removing 
your byline from programs; sandwich 
title and byline REMs between MC 
routines (1, 3, & 5). Pulling line 
2 or 4 will mess up the program. 

Line 1 (16514) contains a MC 
screen reverse routine; POKEing the 
5th byte (16518) with N+l reverses 
the first N lines. 

Line 3 (16556) fills the ZX/TS 
screen fast; the fifth byte (16560) 
again equals one plus the number of 
lines to fill; byte 12 (16571) sets 
the fill character. POKE 16571,0 
(space) to create a "clear screen" 
faster than CLS, and use byte five 
to control how many lines of the 
screen you clear. I'm sure you can 
think of other uses. 

Line 5 (16597) directs the 
computer to a wrong character-table 
start address; if byte 2 isn't 30, 
the screen turns to garbage. This 
creates the spectacular flash when 
you hit a zapper (key). 


All 3 machine code routines 
are fully relocatable. 

Line 210 graphics arerinv sp, 
inv inv ,, ." f inv "*", gr "A", 

"*" f . The remaining graphics 

should be quite apparent. 

Lines 650 and 750 set how much 
time you have to zap each invader; 
it gets shorter as you go along. 

You try to destroy 10 invader 
pairs as they appear on screen. To 
shoot, you must depress the key 
corresponding to invader position. 
For example, press "1" if the inva¬ 
der is in the upper left corner, 
"enter" if it's all the way to the 
right a little below center, and so 
on. SHIFT and BREAK are unused. 

You score when you hit the 
second of each pair of invaders; 
the first ("Syncloid robot") 
generates an "invisibility field" 
that hides the actual invader 
("Synclon", the one you get points 
for.) If you miss the robot, the 
field disturbance is enough to 
tingle the Synclon's antennae, 
giving away his position; so if 
you're fast you can nail him even 
with the field still in place. 
Perfect score merits a special (and 
rather patriotic) display. 

Have fun!! 




42 12 64 6 

4 5 200 24 

24 241 42 12 

6 25 126 254 118 32 

4 3 198 128 119 35 

2 64 6 24 126 254 

5 200 24 2 54 27 

35 24 242 62 30 237 71 201 

BEYOND 64K... 

Would you believe up to ONE MEGABYTE? 

Memory expansion is only the BEGINNING of the possibilities available through BASICare ... the ONLY expandable- 
expansion system for Timex-Sinclair computers. 

This is a unique flexible ‘Building Block’ expansion system that enables you to expand your system in any configuration you 

ASICare Modular Expansion Systems can ‘grow’ on Timex Sinclair 

TS1000 microcomputers ZX81 

To order call toll-free 800 - 833-8400 In New York call (716) 874-5510. 

|l| The phones are open 9AM - 10PM (E.S.T.) Monday to Friday. Call or write for further information. 

BASICare is available direct from fSK ft ft^TT^t ft f" ELECTR ONICS and from selected dealers. 
&h»oIa mv 14017 WMmtMMm m m m'm Dealer enquiries welcome. 

Kenmore Ave., Buffalo, NY 14217 

BASICare modules are what is required to turn any Timex 
Sinclair into a serious computer for business, education, 
industrial, and hobby applications. Your system can grow 
gradually as you can add new functions when and as required. 
In order to open the door to this exciting new world of 
expansions you require a Persona module. It simply (and 
firmly) plugs into your computer. No soldering. No 
modifications of any sort! 

BASICare uses a unique 64 way Organic Bus. This bus is the 
pathway to all modules. You have INSTANT access to all 
modules simply and easily through the PEEK and POKE 

Memory can be added AS REQUIRED in blocks of 16K or 64K 
up to one MEGABYTE. This is memory that is INSTANTLY 
AVAILABLE. This is unlike any other system available for a 
home computer and compares in capability to multi-tasking 
systems costing thousands of dollars! 

You can grow gradually, adding memory or other functions as 
you need them. Just think of the added power expandable 
memory will provide! 

The PERICON modules add Input/Output functions like driving 
relays, LED’s or a Centronics type printer. 

The DROM offers a PERFECT alternative to tedious cassette 
saving and loading by holding your programs and data in non¬ 
volatile RAM. 

These, combined with the other BASICare modules, put YOU 
in complete control. 

Expansion System the modules will never become redundant. If you 
eventually change to a bigger, more powerful computer, the chances 
are that we will have a Persona interface to allow you to use your 
modules on the new equipment. 

PERSONA: —Interface 
module to enable BASICare to 
grow on your computer $ 59.95 
MINIMAP: —Memory mapping 
to extend the address space 
beyond 64K to 1 Megabyte. 

$ 59.95 

RAM 16: —16K add-on 
memory. $54.95 
RAM 64: —a TRUE 64K add¬ 
on memory. $ 149.95 
DROM (2K): —Ultra low power 
memory backed by a 
rechargeable battery for non¬ 
volatile storage of programs 
and data $ 74.95 
USERFONT : —Provides user 
definable characters for DROM 
and TOOLKIT. $17.95 

PERICON a: —A general- 
purpose, user programmable 
device providing 24 lines of, 
input output. $ 54.95 
PERICON b: —24 lines ot 
heavy duty output to access 
and control the outside world. 

$ 59.95 

PERICON c: —To drive an 80 
column printer with Centronics 
type parallel interface $ 74.95 
SONUS: —Three voice music- 
sound synthesizer with 
independent envelope control 
under BASIC commands. 

$ 59.95 

TOOLKIT: —An 8K module of 
utilities in EPROM ROM 


While I'm eagerly awaiting the 
TS2068 I'm concerned that I cannot 
load my ZX/TS programs from tape. 
Will a program to allow this be 
available soon? 

Sigmund T. Mentzel, Crown Point, IN 

Probably. UK customers can now buy 
a program, ZX SLOWLOADER, to read 
ZX81 tapes into SPECTRUM, let you 
modify them, then save in SPECTRUM 
format. It may not work directly, 
but I expect equivalent products 
for the 2068—KO. 

(-10 East London Robotics, Gate 11, 
Royal Albert Dock, London E16, UK 
Tel. 01 474 4430, VISA, 24-hours) 

When I attach a 64K memory to 
my ZX/TS, I can't use more than 16K 
of its capacity. Should I modify 
my ZX-81 as John Oliger recommended 
in SQ Summer 83 p.47? 

John K. Mitchell, Westwood, MA 

ZX/TS machines will not set RAMTOP 
above 16K by themselves; you must 
POKE locations 16388 & 16389 to set 
it higher. John's computer change 
allows you to run machine code in 
the 16-32K block of RAM. If you do 
make the change, tie pins 1 & 13 of 
the 74LS10 to Vcc (Jul.83 p.2)—KO 

_ I suggest two improvements in 
publishing machine code listings. 
Please state when the routines can 
be relocated. In those cases where 
the code is not relocatable, please 
point out or mark absolute codes 
and addresses to recalculate for 
use in other memory locations. 

This would save time for those 
of us who try to relocate code and 
then find that it won't run without 
some alteration. 

R. Harder, N. Vancouver, BC, Canada 

MC authors, please tell SYNTAX what 
to point out and we'll comply—KO. 

I found your information on 
modifying "VU-FILE" very useful 
(Sep.83 p.13). Converting Sinclair 
programs to QSAVE has stopped me 
cold with my limited knowledge of 
programming. Please publish more 
in-depth solutions to convert 
such programs as "Checkbook 
Manager" and "VU-CALC" to QSAVE. 

A. Sloan, Green Bay, WI 

I subscribe to your magazine 
and find it most informative; maybe 
someone can help me. The Psion 
Flight Simulator is entertaining; 
adding a joy stick could make it 
better. Recently I bought Zebra's 
adaptor which accepts an Atari joy 
stick. Sadly, the program is not 
designed for a joy stick and the 
instructions with the adapter for 
adjusting the Program did not help 
me. I am not an experienced 

I hope you can help, I know of 
at least 4 other persons who have 
the same problem. 

Bob Eikhof, Warwick, NY 

We've also had a request to modify 
The Fast One to 64K. SYNTAX needs 
help from readers to do these—KO. 

Occasionally the H,J,K,L half¬ 
row of my ZX/TS keyboard locks or 
else prints blank spaces. Thinking 
it was a heat problem, I drilled 
holes in the case. At the same 
time, I cleaned the contacts of the 
keyboard plugs. After about a week 
it began locking-up again. Any 

Don W. Downs, Bourbonnais, IL 

Check the schematic (SQ Winter 82), 
that half-row goes to A14 through a 
diode. How does ENTER behave? Any 
open (solder joint, diode, cable) 
locks a half-row. Is the logic 1 
of A14 marginal? The Z80 could be 
becoming heat sensitive. Printing 
spaces instead baffles me—KO. 


I had a problem with a TS1000 
which, with a 64K RAM, developed 
temperatures of 95-100F measured on 
the keyboard face just over the 
heat sink using a thermometer 
covered with aluminum foil. After 
a crash, applying ice restored the 
machine immediately, verifying the 
heat problem. 

I reduced the supply voltage 
by inserting a series resistor in 
the plus power lead. Since my unit 
with 64K RAM attached draws 0.6A, I 
used 2 Ohms. This cuts the applied 
voltage by 1.2V. When connected, 
the voltage at the ZX/TS power inlet 
measures 8.1V. 

Now, temperature at the face of 
the keyboard does not exceed 85F at 
74F room temperature and I can keep 
the computer on for many hours with 
no heat problem. 

Use more resistance for lower 
current drawn by attachments. You 
must calculate resistor values so 
that the voltage doesn't fall below 
7V even with power fluctuations. 
About 8V seems a good compromise. 

Frederick M. Lewis, Burnt Hills, NY 

All the power supply tips and 
fixes I see replace or improve the 
9V input to the computer. 

I use a 5V-6A, regulated, 
adjustable, regulated power supply 
with OVP directly to the board, 
bypassing the ZX/TS regulator. 

Is this dangerous? 

Mike Thornton, Borrego Springs, CA 

Fred's problem points to 7805 ther¬ 
mal shutdown, 5V goes away and 9V 
goes up. Mike's solution presents 
no danger, but accessories that use 
9V from pin 2B of the edge connec¬ 
tor do not work—KO. 

You can defeat the "Program 
Access Security System:" use good 
ole...SAVE CHR$ USR 832"name". As 
the program SAVES, hit BREAK. 

Michael Bowman, Arab, AL 

On p.13 Jun.83, you inform Mr. 
Brandao about the "input" level for 
MIC plugs being 5 mV peak to peak. 

I don't understand; do you mean the 
ZX/TS MIC jack OUTput? While we're 
at it, what INput level does the 
EAR-jack need for proper loading? 

Cedric Bastiaans, Los Angeles, CA 

OK, one man's Mede is another man's 
Persian, and computer output equals 
recorder input. In any case: at 
MIC jacks, signals equal 5 mVpp; at 
the EAR jack, about 4.5 Vpp. TTL 
levels also work as EAR jack inputs 
SYNTAX Jun.83 p.20—KO 

Timex left out 2 key commands 
from their VU-CALC documentation. 

"p" copies the screen to the prin¬ 
ter, and "D" deletes a formula at 
the cursor position. (Sinclair and 
Psion included these instructions— 
KO.) VU-CALC is NOT compatible 
with Memotech interfaces. 

Sometimes my Gemini 10 printer 
omits characters or prints in the 
wrong place. Memotech checked out 
my interface, and my printer checks 
out. Could this be an incompatibi¬ 
lity between the interface and the 
printer? Memotech is by far the 
nicest company I've dealt with and 
their helpfulness is to be praised. 

Jim Payne, Dover, DE 

Yes, but if you can determine the 
pattern of behavior, you can prob¬ 
ably overcome it. Test for code 
or character sequences that cause 
this problem. Let us know what you 
find—maybe we can cure it—KO. 


Paul Donnely reports you can buy: 
TS1000+16K RAM+3 Software Packages 
from Yair Imports, E. 45th St. or 
47th St. Photo, 67 W. 47th St. all 
for $49.99 total. You can call 
47th St Photo at 800/221-7774 or 
800/221-5858 or 212/260-4410. He 
says Frogger is available. 



Many of us are trying to find 
out which peripherals work with 
what machines. Information is very 
sketchy, but here's what SYNTAX has 
learned so far. 


So far, we know of no ROM 
changes in the 1500. The keypress 
channel changing (see p.8, TS1500 
manual) uses hardware; Timex says 
no ROM entry point changes. 

starter tape into the 2068. BASIC 
programs LOADed and ran. MC gave 
out of memory reports and would not 
run, but the loading patterns look 
correct in the border. 

ZX/TS software, including MC, 
runs on the 1500. All programs in 
this issue were tested on both. 

Third-Party Hardware 

All ZX/TS peripherals that 
extend more than 1 3/8 inches to 
the left (viewed from the keyboard 
side of the computer) of the edge 
connector or more than 3/8 inch to 
the right, need an extender about 1 
1/2 inches long to clear the power 
and video cables. The printer plug 
of your TS2040 will do. 

Jerry Minchey of Byte-Back 
reports that they tested all their 
modules and all Byte Back modules 
function with TS1500S. But new, 
wide modules need a 1 1/2-inch 
extender plug ($6.95+$3 S&H) so you 
can connect the cables to the rear. 
Old, narrow module designs plug on 
directly. Or, use Computer Conti¬ 
nuum's flexible cable. 

Jerry also informs us that BB 
64K memories work with the TS1500 
because they don't disable internal 
RAM—rather, it runs in parallel. 

Memotech says their RAM packs 
don't work with the 1500, but they 
received no other problem reports. 
When SYNTAX checked, Memotech had 
not tested for problems. 

Timex Hardware 

Timex changed RAM CS on the 
edge connector to RAM RM. Edge- 
connector pin assignments are on 
p.150 of the TS1500 manual. When 
you attach an external 16K & pull 
RAM RM high, the internal memory 
goes to 16-32K. (This puts system 
variables in the external RAM—KO) 

In their OCT.83 newsletter, 
the Boston Computer Society says 
that TS1500's use an octal bus 
transceiver (74LS245) to partition 
the data bus. BCS had suggested 
this technique to modify your ZX/TS 
in the SEP.83 Sinclair-Timex User 
Group Newsletter. 

TS2040 printers work with all 
the machines, but we hear that 12- 
15% of early 1500s might not drive 
the printer properly. 

TS2068 edge connectors differ 
from both 1000s & ZX SPECTRUM—and 
the manual does not contain the pin 
assignments. Differences include 
both the number of pins and the 
function performed by a given pin. 
(Sinclair similarly altered the 
locations of some functions between 
the ZX81 and the ZX SPECTRUM. 


Keys of 1500s move, are soft 
gray rubber, use white characters 
and graphic symbols and black shift 
functions. Three 1500 keys occupy 
the same space as four ZX/TS keys. 
Markings are rearranged—primary 
character at top center, shifted 
character at bottom left, graphic 
at bottom right. 

TS2068 keys move, are hard 
white plastic with comfortable 
left-right dished tops, use black 
characters & graphics and show the 
symbol shift characters in white on 
black bands across the key bottoms. 
Key spacing is also 4/3 bigger than 
ZX/TS spacing. The 2068 offers two 
caps shift keys, a separate symbol 
shift key, a BREAK key (physically 
separate, but electrically another 
space key) and a long space bar. 



ACCOUNTS, an accounting pro¬ 
gram for small businesses, compu¬ 
terizes your DOME monthly account¬ 
ing book. It allows up to 240 
accounting records, either debit or 
credit, in 40 different categories. 
You choose each code definition. 

Menus and prompts guide you. 
Usually ENTER moves you along to 
the next phase, but if all else 
fails, simply GOTO 10 to return to 
the menu. DO NOT RUN! 

After loading ACCOUNTS, you 
see its menu and control portion 
(lines 10-170). Just touch the key 
for the first letter of each option 
to invoke it. Each option returns 
to the menu upon completion. 

If you choose BEGIN (lxxx), 
the program clears all data and 
variables and asks for data input. 
Respond to DATE with six charac¬ 
ters, year first; TO/FROM with up 
to 15 characters; REASON up to 10 
characters; CODE with two-character 
account code; and AMOUNT with dol¬ 
lar value. As written, the first 
32 codes automatically debit (no 
minus sign required, but the pro¬ 
gram stores the value as negative). 
Correct any item during entry using 
the DELETE key. You get a chance 
to check your entries before choos¬ 
ing YES or NO. After your last 
entry, use QUIT instead of YES to 
return to the menu. A flashing 
message tells when you can enter 
only five more records. 

CONTINUE (2xxx) works like 
BEGIN, except it does not clear 
previous data. Instead, it appends 
new data to the previous records. 

VIEW (3xxx) lets you scan 
entries by year or month. As the 
screen fills, ENTER makes room for 
more. Finally you see a summary. 
This takes the longest due to the 
ROM's floating point calculator. 

PRINT (4xxx) sends selected 
records and summations to an 80- 
column printer. Change the for¬ 
matting here for a 32-column print¬ 
er. CHR$ 155;"A" gives carriage 

return/line feed via Memotech's 
I/F, for which I wrote this pro¬ 
gram. The 80-column printer gives 
neat, formal accounting reports. 

FILE (5xxx) presents facts 
about file and space usage, includ¬ 
ing records used, contents of last 
record and total program and vari¬ 
ables size. 

EDIT (6xxx) allows selected 
altering or deleting of records. 
DELETE merely nulls a record and 
does not physically remove it. If 
space gets tight, you may ALTER new 
data into a deleted record. Unlike 
BEGIN, when editing you must put a 
negative sign in the AMOUNT field. 

SAVE (9xxx) sets up cassette 
save of program and data. Just 
ready the cassette in record mode 
and enter the name under which you 
want to save the program. 

Subroutine at lines 7xxx gives 
start and stop parameters for VIEW 
and PRINT options. 8xxx adds en¬ 
tries within each account code. 

You can get a tape of this 
program for $3 from me. 

James R. Shoaf III, POB 2147, 
Santa Clara, CA 95055-2147 


D(240) stores DATE (numeric) 

A(240) stores AMOUNT 

T(40) stores each acct subtotal 

Q(3) stores credit, debit and net 


C$(240,2) stores acct CODE (string) 
Y$(240,10) stores REASON 
W$(240,15) stores TO/FROM 
Z$(15) stores SAVE name, misc. 

X contains number of records used 
I loop counter during data input 
M loop counter during VIEW and 

F loop counter for flashing message 
K loop counter during summation 
N indicates current record 
L indicates month 
Z indicates year 
G indicates start time 
S indicates stop time 
R indicates items per display 




O Q 


One of our research programs at 
Clover Bottom Developmental Center, 
a state facility for the mentally 
retarded, seeks ways to measure 
intellect in quadraplegic, non¬ 
verbal children. Their severe 
motor impairments prevent valid 
estimates of intellect—they can't 
reliably make gross motor or verbal 
responses. Children so afflicted 
might be thought mentally retarded 
because we cannot measure the 
childs potential. 

We are evaluating a procedure 
to find a reliable motor function 
that such a child can control; re¬ 
inforce the exercise of that func¬ 
tion, and teach the child to use 
that motor function to communicate. 

Briefly the research program 
sequence seeks to: 

o Identify possible voluntary 
motor functions that could be 
used to operate a switch. 

o Design and construct a suitable 
switch and appliances matched to 
the child's existing voluntary 
motor functions. 

o Establish an operant-conditioned 
response using selected stimuli to 
reinforce switch activation. 

o Test conditioned responses with 
various discriminative stimuli. 

o Use a demonstrated, reliable 
response in a program combining an 
inexpensive microcomputer and human 
interaction to train the child in 
language expression. 

Steps 3 and 4 employ the ZX/TS 
to collect real-time data and, at 
the end of each session, to analyze 
the data. Step 5 uses the computer 
for computer-assisted instruction 
in communication skills. 

Information collected and 
stored by the ZX/TS includes: 
child's name, date, time of day. 

session length, number of switch 
operations, duration of each 
closure and percent of time the 
switch was activated. 

We selected the ZX/TS because 
it's low-cost, easy to alter, low- 
powered (permitting economical and 
portable battery operation), expan- 
dible, furnished with a complete 
BASIC, & uses a membrane keyboard. 

Responses by the child simu¬ 
late key presses. We simply wired 
a jack to the keyboard circuit to 
connect the external switch. 

William F. Tracy, Nashville, TN 


Owners of ZX/TS and Atari 400 
computers probably find membrane 
keys the weak point. Non-respon- 
sive keys, from misplaced or weak 
finger pressure, sneak errors into 
programs. To avoid dropped charac¬ 
ters, one must watch the screen 
while entering. This slows keying. 

Several vendors offer add-on, 
full-movement keyboards or overlays 
to position the fingers correctly. 

But the problem really comes 
from treating membrane keyboards as 
typewriters. Typing skills, even 
ideas of how typing movements look, 
mislead us. Tapping membrane keys 
often produces errors. Never mind 
the similarities, a membrane isn't 
a typing keyboard. 

Upset at this shortcoming, I 
experimented. I now cut errors and 
speed programming by pressing a key 
near its upper edge, and rubbing my 
finger over the key with enough 
force to make a slight "pop." 

I can now type in—or should I 
say rub in—several lines with no 
need to check my screen for errors. 
With practice, this method proves 
fast and not especially awkward. 

So, before you invest in an 
add on keyboard, try this method. 
You may save yourself the price of 
that peripheral you're saving for. 

Michael R. Watson, Sonoma, CA 



Name: Analogies, Logical Reasoning 

Type: Educational 

ROM/RAM reqd: 8K/16K 

Listable? Yes 

Printed listing? No 

Written in: BASIC and MC 

Easy to load? Yes 

Display: Good 

Price: $14.95 each 

From: Windcrest Software Inc. 

POB 423, Waynesboro, PA 


Analogies and Logical Reason¬ 
ing, two separate programs, pleas¬ 
antly teach important concepts in 
logical thought. I found each 
suitable for junior high and up. 

Analogies comes with two pro¬ 
grams, one a demo containing 25 
analogies and explanations of how 
analogies work. The computer gives 
the first three words; you supply 
the last. For example, pride: 
lions::gaggle: You answer geese, 

because a pride is a group of lions 
and a gaggle is a group of geese. 
The computer scores your analogy¬ 
perceiving ability. The analogies 
range from simple to clever. 

On the other side you find an 
analogy utility that lets you easi¬ 
ly create your own analogies. You 
enter all four words plus an ex¬ 
planation for users who do not 
guess correctly after two tries. 

Logical Reasoning introduces 
conditional statements, contraposi- 
tives, converse and inverse state¬ 
ments, direct and indirect proofs 
and the invalid logic of analogies, 
circular arguments and generaliza¬ 
tion clearly and simply. It uses 
tests, drawings and puzzles to 
cleverly demonstrate logic. Learn¬ 
ing how Sherlock Holmes knew which 
of the three men lied and exactly 
how many coins they found in the 
treasure through indirect proof 
held my attention for an hour. 

On tape you get 12 programs to 
load one at a time, including a 
pre- and post-test. The computer 


Suite 75 STX 
J 711 Southern Artery 
I Quincy, Massachusetts 02169 
V (617)773-1187 

asks your name and manages to re¬ 
member it through all 12 even 
though you load new programs. It 
also assures that you don't skip 
lessons by requiring an entry code 
if you don't go straight through. 

Problems: Both programs con¬ 

tain annoying misspellings. This 
proved crucial only in Analogies, 
where the computer rejected my 
(correct) spelling of venison. Al¬ 
so, inquiring minds may find the 
programs run slowly. Windcrest 
should make Analogies self-running, 
since mistakenly starting with RUN 
destroys the analogy sets. 

Each program comes attractive¬ 
ly packaged like a book and in¬ 
cludes a short instruction manual. 

Windcrest makes game and edu¬ 
cational software for several dif¬ 
ferent home computers on both tape 
and disk. I'm glad to see them 
offering such high-quality educa¬ 
tional software for ZX/TS users. 

Ann L. Zevnik, Boston, MA 



Name: Multiple Regression Analysis 

Type: Statistical Analysis 

Price: $15.95 

ROM/RAM required: 

Printed Listings? 

Program Listable? 

Easy to load? Yes 



Programmers at Large 

8K/16K min. 



Easy to use? 
Written in: 

POB 24362 
Fort Worth, 

TX 76112-9362 

This program does a very good 
job number crunching. To test it, 
I used data involving 95 observa¬ 
tions on 8 variables. An IBM-360 
mainframe gave me these results: 


In using multiple regression, 
you must know whether the data has 
multicoilinearity. (Multicolline- 
arity results when two or more 
independent variables are correl¬ 
ated. For example, if you want to 
develop an equation to predict the 
density of water using observations 
on the height from sea level, tem¬ 
perature in degrees C and degrees 
K, you would find perfect correla¬ 
tion, and thus perfect multicol- 
linearity, between the two tempera¬ 
tures. This renders the resulting 
equation invalid.) In research 
using regression, we commonly with¬ 
hold some data when developing the 
equation. Then we apply this data 
to the resulting equation to see 
how well it predicts. MRA does not 
let you use the equation at all. 

You need not redimension five 
arrays. Delete lines 3, 4, 10, 15 
and 20 and add: 


3.67X(7) with r 2 =.95 and F=237.8 
My ZX81 and this program gave: 

3.673X(7) with r 2 =.95 and F=237.15 

While MRA crunches numbers 
well, it displays three major cate¬ 
gories of flaws. One, it is not 
user-friendly. Two, it leaves out 
important results. And three, it 
shows evidence of poor programming. 

According to the instructions, 
you should redimension five arrays 
based on the number of variables 
and observations, but the instruc¬ 
tions don't tell you how and the 
program self-starts. They indicate 
that with 20 variables and 200 
observations you would DIM T(4000), 
but 16K will not allow this. The 
program does not let you review 
data entered to check for errors 
nor correct data. 

101 DIM T(N*M) 

102 DIM M(N) 

103 DIM Y(N) 

104 DIM X (N) 

105 DIM R(N* (N+l)) 

At a cost of seven bytes, the pro¬ 
gram now self-dimensions. 

MRA wastes about 130 bytes on 
REM statements and 20 bytes by us¬ 
ing E-N-T-E-R instead of ENTER in 
PRINT statements. It uses no 
string variables although this 
would also save memory. 

As MRA now stands, I cannot 
recommend it. I had to spend sev¬ 
eral hours cleaning up major flaws 
before I could test it. Developing 
a multicollinearity matrix may ex¬ 
ceed the limits of a 16K machine, 
but all,my other corrections result 
in a net memory savings. If the 
authors correct these flaws, I 
would rate MRA as excellent. 


Ronny Richardson, Chamblee, GA 


Program: Mazogs 
Type: Maze game 

ROM/RAM reqd: 8K/16K 
Printed listings? No 
Listable? Yes 
Easy to Load: Yes 
Written in: BASIC and MC 
Display: Superb 

From: Softsync Inc., 14 E. 34th 

St., New York, NY 10016 
Price: $19.95 

Few ZX/TS programs can claim 
Mazog's excellent union of strate¬ 
gy, display and sophistication. 

In this high-speed game you 
navigate an intricate maze in a set 
number of moves to find a treasure 
and bring it home. Ugly Mazogs 
along the route try to kill you. 

You can only win more moves by 
killing Mazogs; if you run out of 
moves you die. To kill the vile 
Mazogs, you find swords, but each 
sword serves only one use. The 
program carefully balances the num¬ 
ber of swords and Mazogs en route 
to the treasure, and the ratio 
becomes more adverse as you rise to 
higher difficulty levels. 

Besides swords and your wits, 
you use prisoners trapped in the 
walls who tell the way. The route 
appears for about 10 seconds, then 
vanishes, leaving you on your own 
again. In the advanced level, 
prisoners die after pointing the 
way, making it near impossible to 
find your way back home if you use 
them all to find the treasure. 

Any time you may view a larger 
section of the maze, at a small 
cost in moves; you can also learn 
your distance from the treasure or 
your base, again, at a cost. You 
can even buy a sword for the not- 
so-small cost of half your remain¬ 
ing moves. 

Mazogs includes professional 
and effective touches that make it 
worth its $20 price tag. These in¬ 
clude a running title screen (you 

mstock! ALL NEW MD-2 



• Send Text from Memory 

• Send and receive Programs by Ph| 

• Copy Information into memory i 
Print it Review it. Save it on Tapel 

• Use Timex 2040 Printer or RS-232 

• RS-232 Printer Port provided 

• No extra memory Required. 


64-K MEMORY $109? 5 k.t 


• Battery Backup • PROM/ROM socket 

• Reset Switch • BYTE-BACK EXCLUSIVE FULL 64 -K 



KEYBOARD.$59. 95 


NEW ZX PRO/FILE including shipping 
Clearly the Best File Management Program Available. 
CONTROL MODULE 8 Relays,8 Inputs, $59. 95 KIT$69. 95 ASSEMBLED 
16K MEMORY UM16 $59. 95 KIT$69. 95 ASSEMBLED & TESTED 
Battery Backup, reset switch, PROM/ROM socket PLUS . . . 

1 year, 100% Trade-in credit towards the UM-64._ 


Rt. 3, Box 147, Brodie Road 
Leesville, S.C. 29070 
ORDER PHONE 803-532-5812 
Add $4.95 shipping and handling 
90 Day Warranty On All Modules. 10—Day Return Priviledge 


see all the objects before play¬ 
ing) , the effective key layout (ac¬ 
tually giving a choice of control 
keys—I found both sets easy to 
handle) and an involving display. 

Machine code provides visually 
effective and speedy animation for 
on-screen figures and your man's 
combat contortions. The MC also 
quickly solves the maze when you 
ask a prisoner and the full-maze 
scrolling and solution at the end. 

Mazog's complexity lies in the 
challenging difficulty of the maze 
and escaping with the treasure, not 
in mastering odd keyboard layouts 
or confusing screen displays. A 
game not easily mastered, it won't 
sit dusty in your collection. And 
make a backup —I wore my original 
out after two weeks of continuous 
use. This is the finest game of 
its type I've seen for ZX/TS's. 
Even a friend who owns an Apple 
said "Wow" when he saw Mazogs. 

William Marriott, Canton, MI 



Refining Ron Oblander's chart 
(Nov.82) makes it run faster and 
puts table and chart on 1 display. 
But, it omits the segment titles. 

After entering PC, SAVE using 
GOTO 970. It comes up running and 
stops with a 9 report. For another 
chart, RUN again. 

After a title screen, PC asks 
the number of segments. You enter 
up to 18, the most the table holds 
on one screen. Then enter segment 
values one by one. After the last 
value, the computer shifts to FAST 
for about 6 seconds to produce the 
pie outline and table heading. Now 
in SLOW, the computer lays in the 
segments and table. At the end you 
can COPY the screen to a printer. 

On the chart, segment 1 starts 
at the 12 o'clock position; others 
follow serially clockwise. The 
table gives segment number, value, 
percent of pie, & total of values. 

Variables Q and R control pie 
position and radius. PC puts the 
pie in the lower right corner with 
an 18-pixel radius. The trig work 
exploits ZX/TS's internal MOD 
feature. One array, E(C), holds 
each segment value. I serves as 
index variable in two loops. You 
can use tokens in the print state¬ 
ments (Syntactic Sum here is for 
words spelled out.—AZ). Variable 
N0 carries the number 0. 

John Pazmino, Brooklyn, NY 

CLASS IFIED ADS; Reach thousands of 
ZX/TS users—just $9/line! We must 
receive your typed copy (35 charac¬ 
ters per line) with check or money 
order by the 15th for publication 
in the next issue. We print ad ex¬ 
actly as you type it. No fractions 
or cent symbols. Include your 
phone number, SYNTAX, Classified, 
RD 2, Box 457, Harvard, MA 01451. 

INFO. SERVICES (TS1000/1500). $20. 
UCLA Course Notes. MC/VISA (213) 
760-8110. Cibbarelli, 11684 Ventura 

#295, Studio City, CA 91604 



$ US 


Zilog Z80-Z80A Tech. Man 



Zilog Assy Lang Prog Man 



Crash Course in Micros 

Hardware and Mach Lang 



Exper. in Artfcl Intell 

AI Programs for Micros 



Plastic Micro Charts 

Z80 CPU 


8080A & 8085A 




6502 (65XX) 




Any 5 charts for 


Shipping & handling charges: 

Micro Charts $l/order 
Books (except Zilog) $1.50/book 
ORDER by telephone: 617/456-3661 



SYNTAX is published monthly by a wholly- 

owned subsidiary of The Harvard Group. 

Syntax ZX80, Inc. 

RD 2, Box 457, Harvard, MA 01451. Telephone 

12 issues, $29. Single issue, $4. 

Publisher: Kirtland H. Olson 
Consulting Editor: Ann L. Zevnik 
Technical Consultant: Kirtland H. Olson 

© Syntax ZX80, Inc., 1983. All rights reserved. 
Photocopying prohibited. ISSN 0273-2696 


SYNTAX invites you to express opinions related to any Sinclair computer or 
peripheral, or the newsletter. We will print, as space allows, letters discussing items 
of general interest. Of course, we reserve the right to edit letters to a suitable length 
and to refuse publication of any material. 

We welcome program listings for all levels of expertise and written in either 
Sinclair BASIC or Z80 machine code. Programs can be for any fun or useful 
purpose. We will test run each one before publishing it, but we will not debug 
programs; please send only workable listings. Programs submitted on cassette can be 
tested more quickly and with less chance of error. 

In return for your listing, we will pay you a token fee of $2.00 per program we 
use. This payment gives us the nonexclusive right to use that program in any form, 
world-wide. This means you can still use it, sell it, or give it away, and so can we. 

We will consider submissions of news and hardware or software reviews. Please 
keep articles short (350-400 words). Again, we reserve the right to edit accepted 
articles to a suitable length. We will pay 7 cents per 6 characters, including spaces 
and punctuation, for accepted articles. 

When you send in programs for possible publication in SYNTAX, please 
include the following information: 

• How to operate the program, including what to input if it does not contain 

• Whether you can run the program over again and how. 

• How to exit the program. 

• The Syntactic Sum (program published in Feb. 81 and Jun. 81; send SASE 
for a free copy). 

• What RAM size program requires. 

• What ROM program uses. 

We pay for this explanatory text at the same rate as for articles in addition to 
payment for the program itself. 

If you want us to return your original program listing or article, please include 
a self-addressed, stamped envelope. Otherwise, we cannot return submitted material. 

4 Go Forth-GO TREEFORTH 4 

4 Get Out of The Basic ZX-TS Rut 4 
4 Program Ten Simultaneous Tasks 4 
4 Environmental Control Tasks 4 
4 Robotic Control Tasks 4 

4 On 64K EPROM Just Plug It In 4 
4 Power/Speed and Time Control 4 
4 Intro. Price $49.95 + $2.00 P&H 4 
4 Soft Magic Corp. 1210 W High St 4 
4 Bryan OH 43506 419-636-4531 4 

Find out cheap in Programmer's 
Market—get names, rates, topics, 
and requirements in one easy-to-use 
book. Just like the one used by 
free-lance writers to sell stories. 
Includes chapters on how to write 
successful manuals & documentation 
as well as negotiating. Order now. 
Phone orders: SYNTAX 617/456-3661 
$16.95 + $1.50 P&H/book. $1 DISCOUNT 
on multiple copies to one address. 
Pay easy with MC/VISA/AMEX/DINERS 

Dec/Bin/Hex Slide Convertor $3.75ea 
VAN.B.C.V7K 1E7 ($16.25 for 5 CONV) 

Cassette for 165 Detailed Rcpt/Exp 
Entries. $21.95 PP. Transactions 
Auto-Sorted by Date. Review by Many 
Criteria. Auto-Prep of Tax Return. 
Manual Only $4.95. P. Hale Software 
40 Hancock St., Boston MA 02114 

Fill out the coupon below and mail it to: SYNTAX 

□ My check is enclosed. 
Make checks payable to: 
SYNTAX ZX80, Inc. 

Account number 

Exp. date _ 

Signature _ 

Name _ 

□ Please charge my □ VISA 

□ Diner’s Club □ American 
Express □ □ Mastercard 

□ Carte Blanche account 

RD2 Box 457, Harvard, MA 01451 

YES! Please send me: 

sll 83 

.Bank number (MC only) 



Day phone 

.Evening phone 


□ The Combination II (13 issues of SYNTAX and SQ Winter 

82-Summer 83). $39 

□ The Catch-up II (SYNTAX Jan. 82-Jan. 84, SQ Winter 82- 

Summer 83, plus 1 binder) .$77 

□ The Works II (SYNTAX No. 80-Dec. 83, SQ Winter 82- 

Summer 83, plus 2 binders).$97 

□ 12 issues of SYNTAX.$29 

□ 3 issues Syntax Quarterly (Winter 82-Summer 83).$25 

□ 1 issue Syntax Quarterly □ Winter 82 □ Spring 83 

□ Summer 83.$9 

□ 1 Binder.$9 □ 1 issue of SYNTAX.$4 

Telephone orders call 

□ My subscription number is: 

□ This is a new subscription. 


These offers expire 12/31/83 -SUBSCRIBE NOW. 



21551 BROOKHURST 205 H.B.CA92646 


software tapes like a pro!-12.95 

(C) LOST IN SPACE -11.95 







(Requires 16K RAM) GUARANTEED!!!!!! 
Add $1.50 S&H per order. NJ 6% tax. 

BOX 117, OAKLAND, N.J. 07436 

LETTER. XFORTH $25.00. W/ F. P. EXT 
ADD $15.00. ADD $1.00 EACH P. & H. 

ONE TAPE.$14.95 + $1.00 P&H 

(DXERS MUST!).. &17.95 + $1.00 P&H 

DESIGN/TEST_$19.95 + $1.00 P&H 

15,1983 ARK RES ADD 4% TAX. **HAWG 


* Complete 2K kit. $34 :00 * 

* Three more HM6116LP-3... $18:00 * 

* Bare board with manual.. $15.00 * 

* Prices include s&h -from HUNTER * 
*1630 Forest Hills Okemos MI 48864* 


LEDGER-List 300 entries across 20 
columns, review, total and graph. 
FILE:Multiple program with indepen¬ 
dent field lengths and eight fields 
max. Features are ADD, EDIT, SORT, 

Send $11.95 ea. to M*Z SOFTWARE, 

1003 S.CLIFF, PORTLAND, TX 78374 


Turn your program into profits with 
this comprehensive guide. Learn the 
techniques of the pros -pricing, 
packaging, advertising, publishing, 
T/S market trends, program ideas, 
royalties, plus many references. 
$14.95 money order, VISA, M.C. 

210 Fifth Ave, New York, NY 10010 

LOAN AMORTIZATION. Provide any 3 of 
4 factors will calc unknown. Any 
type of payment plan. ZX81-16K cass 
$10. WMJ Data Systems,4 Butterfly, 
Hauppauge, NY 11788 



Bolton Road, Harvard, Mass. 01451 

U.S. Postage 

Harvard, MA 

First Class 









FL 32211