F

SYNTAX

Serving Timex-Sinclair Personal Computers

A PUBLICATION OF THE HARVARD GROUP

VOL. 4 NO. 3

ISSN 0273-2696

MAR. ,1983

IN THIS ISSUE

8K Programs

Math . 8

Where To Move RAMT0P...9

Pledge Keeper..,. . 10

Direct Input Horizontal and Vertical Line

Graphics . 14

Real-Time Soft Clock.. 15

Do Or Die . 18

A Sojourn at

CompuServe . 4

Get Your System

Together . 16

Book Review Computers For Kids — Sinclair ZX81 Edition. 14

Classified Ads . 21

Dear Editor . 12

Hardware Project

Reverse Video Monitor. 19 Hardware Review E-Z Key 60 Keyboard. ... 6 Machine Code Programming Routine Elimination. . . 21 News, New Products .... 1 , 2 Program Improvements....! Software Reviews

Snake . 16

Reference Card . 20

Users' Groups . 3

Vendor Report . 3

TIMEX PRINTERS ON THEIR WAY

Timex printers are en route to distributors, according to a Timex source, and should be in retail stores in March. TS2040 printers offer 32-column thermal printout and require

no interfacing. Price: $99.95.

KOPAK INTRODUCES NEW KEYBOARD

Kopak Creations' new keyboard, ^ready in 15

weeks, plugs into internal ZX/TS keyboard connector. Full-size keyboard features on/ off switch, standard space bar and RETURN, 2 ENTER and 2 shift keys, shift lock and 4 single-stroke keys (comma, colon, $, DELETE). Optional numeric keypad extra (price not set). Preproduction orders $69.95 + $5.50 P&H. Full price is $99.95+$5.50 P&H. Kopak Crea¬ tions, 119 Peter St., Union, NJ 201/864-4410.

DRIVE TO RUN CP/M IN THE WORKS

Kopak Creations and Aerco are working jointly on a ZX/TS disk drive to run CP/M (world's most common disk-based microcomputer operat¬ ing system.) Aerco says the drive will be available in 3 months. Now work continues on the software and getting a license from Digi¬ tal Research, CP/M's orginator. Aerco's spokesperson would not predict the drive's price. Aerco, Box 18093, Austin, TX 78760- 8093, 512/ 385-7405.

Index to Advertisers WANTED: ASSEMBLY LANGUAGE PROGRAMMERS

Brainchild Computer . 4 Proprietary International needs assembly

Byte-Back . 10 language programmers for their unreleased

Discount Software . 6 ZT21000 (Jan. 83). You'll get a production-

Frog Software . 18 model unit, documentation and a marketing

Intercomputer . 7 contract, but you'll pay $1000, says Steve

Kopak Creations, Inc... 17 Zwaska of PI. Send a short resume (with

Memotech Corp . 5 phone number) and sample program (plus check)

People's Computer . 20 by 3/21/83. Info: Randy Wear, 800/356-8392,

Softsync . 11 PI, 131 LaSalle Rd., Streamwood, IL 60103.

NEW PRODUCTS AND SERVICES

New ZX/TS software: Blackjack and Hi-Lo (tape 1); Mastermind, Super¬ mind and Guess (tape 2); Escape, Snake and The Trap (tape 4). Each tape, $10.95. Compuwiz Software, POB 390078, Mt. View, CA 94039.

Plug-in speech module, The Parrot, makes 64 English-language sounds. Combine sounds (allophones) to gen¬ erate words, phrases, sentences and sound effects. Package includes: software, directions, jack for 4- or 8-Ohm speaker. Power socket permits more power. R.I.S.T. Inc., $69.95, 921 Port Washington Blvd., Port Washington, NY 11050, 516/883- 8865. In Canada: Integrated Data Systems, 11 Brighton Ave., Toronto. Ontario, Canada M4M 1PW.

Guide to ZX Spectrum Resources . a 92-page illustrated book, details, reviews British products for the new Spectrum/TS2000. $6.50, Micro¬ scene, 6 Battenhall Road, Harborn, Birmingham B17 9UD, UK.

SCREEN-CALC, ZX/TS electronic spreadsheet program, holds 450 user-defined entries as either in¬ put data or calculated results.

You can define any entry in terms of other entries. Built-in fea¬ tures total and average columns and rows and can locate entries by name. On cassette. Banta Soft¬ ware, 8088 Highwood Way, Orange- vale, CA 95662, 916/722-4895. '

Hidden Words, ZX/TS word search game, conceals words in the playing grid. Word editor lets you change words; four levels of play. On tape, 16K required, $9.95. Soft¬ ware Unlimited, P.0. Box 147, Grandview, MO 64030.

Construct current buffer for tape recorder remote jacks. Excessive current can damage the relays in your ZX99. Schematic package al¬ lows you to construct buffer to

reduce remote jack current to 10 mA. ZX99 can't tolerate more than 130 mA. Schematic package and in¬ formation on constructing current buffer for input/output recorder jacks using simple parts. Z-WEST, P.0. Box 2411, Vista, CA 92083.

KBD-1 keyboard for TS1000 has 58 plunger-type keys, 12 spare keys, internal or external PC board in¬ stallation without solder, full space bar, dual shift keys with shift lock, electronic shift/ un¬ shift, repeat and fast repeat on all keys, keyboard entry disable and instruction manual. $84.95 plus $4.95 P&H. Half-size 5 1/4" disk drive is in the works. SYNER¬ GISTIC, P.O. Box 411023, Chicago,

IL 60641, 312/772-7461.

Machine code debugger for BASIC programs resides in the top 2.5K of 16K. STEP can single-step BASIC lines and be set to RUN to condi¬ tional breakpoints or break after a specified number of loops. $14.95 plus $2 P&H. HOT Z, machine code monitor and disassembler, is now available on four 2716 EPROMs ad¬ dressed to 8-16K memory block.

Chips require Hunter memory board or home-made EPROM reader for ac¬ cess to HOT Z monitor. Four tested 2716s, $40. Sinware, Box 8032, Santa Fe, NM 87504.

Problem Solver, an external voltage regulator, eliminates loading and overheating problems and includes on/off switch. Schematic, parts list, assembly directions, $12.95; kit, $24.95; wired and tested $49.95. Original Programs, 3763 W. Crocus Dr., Phoenix, AZ 85023.

User-friendly 16K Ohm's Law pro¬ gram. On cassette, $15 plus $1 P&H. Keyboard conversion plans for ZX80/ZX81 , TS1000 includes decoding shift keys and reset, $5 plus $1 P&H. Arizona residents add 6% sales tax. Spectra Computer Products, P.O. Box 41795, Tucson, AZ 85717.

2

VENDOR REPORT

USERS' GROUPS

In this new department, you'll find out about ZX/TS vendors — what prob¬ lems exist and which have been resolved, who's in business and who's not. If you're having prob¬ lems with a vendor, let us know. We'll help find a solution. — Ed.

OUT OF BUSINESS: Synchronize, Box 1667, Kerrville, TX 78028, adver¬ tised in Winter 82 SQ. If you have a problem with them, call SYNTAX.

ZXPress Compiler from Non-Trivial Solutions is now available only from Proprietary International.

They should fill all back orders and inquiries before press time.

If you have a problem, contact Randy Wear, Marketing Director, 800/356-8392. PI, 131 LaSalle Rd. , Streamwood, IL 60103.

We've heard complaints about Norris Radio and Electronics' repair and return practices. We telegrammed Tracy Norris about these problems (no phone listed) , but he has not responded. Norris is a ZX/TS re¬ pair shop in Slidell, LA.

Neither have we heard from SMUG, the Sinclair Midwest Users' Group in Fort Wayne, IN. Some readers wrote they did not receive software they ordered from SMUG. Last month we wrote to SMUG to inquire; we'll let you know if they answer.

Gladstone Electronics is working on catching up on their US shipments. Readers have reported receiving cancelled checks promptly, but no merchandise up to two months later. Howard Gladstone says US shipments are now about 4 weeks behind, with Canadian shipments on schedule.

They increased their staff and shifts to remedy the problem. You can now talk to Gladstone until 1 AM EST. Ask for head troubleshoot¬ er Pauline Sampson in Buffalo, NY, at 716/874-5510.

Bakersfield, CA: Bakersfield Timex/Sinclair Users' Group, Don Stewart, 2617 Anza St., Bakers¬ field, CA 93305, 805/871-7024.

Detroit, MI: Sig-Sinclair c/o SEMCO, Don Bicht, P.0. Box 02426, Detroit, MI 48202, 313/535-6253.

Fredericton, NB, Canada:

Fredericton Sinclair/Timex Users' Group, John Palmer, Fredericton,

NB, Canada, 506/454-0705.

Huntsville, AL: Sinclair Users' Group, Bob Boyle, 7705 Martha Drive, Huntsville, AL 35802, 205/883-4354.

Manitoba, Canada: The Manitoba Telephone Systems Sinclair ZX81 Systems Users' Group, Ben Landry, 204/888-4516.

Modesto, CA: Time-Sync Group for Central Valley California, Thomas Eckle, 3716 Corte Madera St., Modesto, CA 95350.

Palatine, IL: The Sinclair Users' Network (SUN) , nationwide users group. Diana Wright, 2170 Oak Brook Circle, Palatine, IL 60067, 312/934-9375.

Portland, OR: Portland Area Timex/ Sinclair Users' Group, Michael Veine, P.0. Box 3153, Portland, OR 97208, 503/774-9637.

Redwood City, CA: ZX Micro Club, c/o Ampex Corp., Don Femling, 401 Broadway M.S. 2-04, Redwood City, CA, 415/367-3454.

PROGRAM IMPROVEMENTS/REFINEMENTS

To get a heart without a bite taken out of it in Sweetheart (Feb. 83) change line 120 to: FOR B=7 TO 24. New Syntactic Sum is 22457.

John Sampson, College Point, NY

3

CHANGE YOUR

TIMEX/SINCLAIR 1000 DISPLAY TO FULL COLOUR GRAPHICS

with

KOLORWORKS

LOOK AT THE FEATURES ! ! !

* Plugs into ZX81/1000 (edge connector)

* All text will run on the color tv

* Module contains it's own memory

* User defined characters & graphics up to

256x192 pixels

* Latest technology with TMS991 8 VDP

(32 sprite levels)

* Module contains extension of basic commands

including: PAPER/INK/BORDER/BIN/ SPRITE/OUT/INP / etc.

for $149.95

Use your KOLORWORKS immediately with a game cassette for $9.95

This delightful game is designed for hours of fun using some of the color graphic capabilities of KOLORWORKS. The cassette also contains a short program to familiarize you with some of the commands and graphics.

MAIL TO:

BRAINCHILD COMPUTER WORKS, INC. P.O. Box 506 Pewaukee, Wl 53072

Price + Qty. _ Am ou nt

KO LOR WOR KS	$149.95
CASSETTE	9.95
Shipping and Handling	4.95	$4.95
Wi. Res. add Sales Tax
My n check EH money order enclosed	TOTAL

Name

Street _

City _ State _ Zip

Please allow six to eight weeks for processing. Thank you.

For further information - Send $2.00 (credited to order) WATCH FOR:

"GAAMWORKS" -

Joystick Ports / Sound / Cartridge Slot

A SOJOURN AT COMPUSERVE

CompuServe Information Service is available to ZX/TS owners with a modem and the proper software. (Modems allow two or more computers to communicate via phone. SYNTAX Jan. 83 describes one available ZX/TS modem.) For $5/hr. (initial $100 subscription fee), you get: electronic mail, newspapers and magazines, banking, games, SIGs (Special Interests Groups) , and a special programmers area. You can also store programs, up to 64K, at no extra charge!

To access the system, you need a user number and password which you get from computer stores or CompuServe (800/848-8990? in Ohio call 614/457-8650). They also ex¬ plain log-on procedures and how to hook up to the system.

CompuServe uses prompts throughout. Because the menu is slow, I prefer GO statements. For example, if I tire of playing Wum- pus, and want to call the Work-at- Home SIG, I enter GO HOM-146 at the prompt. CompuServe's computer then looks up the particular disk file and lets me access it.

This system supports many var¬ ied SIGs. One or more SYStem Oper¬ ators run each SIG. SYSOPs manage the SIG, moderate the SIG C.B. sim¬ ulator, keep SIG database files neat and help newcomers.

SIGs cover the entire world of computing in the Personal Computer Service area. That is, except for ZX/TS computers. But there's hope. I talked, via computer, with SYSOPs on Computer and Electronics maga¬ zine SIG. They welcome a ZX/TS SIG in their group (GO CEM-450) and have a database available for ZX/TS computer users.

Patrick Spera, Tinker AFB, OK

For more information, contact CompuServe Corporate Headquarters, 5000 Arlington Centre Blvd, Colum¬ bus, OH 43220.— Ed

4

THE POWER.

AND THE GLORY.

Sinclair

TIMEX has given the world a breakthrough in personal computing power at an affordable price. Now, to the power of the TS-1000, you can add the glory of MEMOTECH ... of “piggy-back” compatibility: increased memory, a user-oriented keyboard, a printer interface, a full spectrum of printers, high resolution graphics and a remarkable range of new applications.

In short, MEMOTECH offers you the high-quality peripherals that turn an introduction to computing into a versatile, full-powered computer system.

New from Memotech . . . the TS-1000 keyboard. And state-of-the-art printers.

Keyboard. The Memotech keyboard is a standard (Typewriter) keyboard with TS-1000 legends. The keyboard is cable-connected to a buffered interface which is housed in a Memopak case, and plugs directly into the back of the computer or other Memopaks.

Printers. Memotech offers you a wide range of high quality printers . including the SEIKOSHA GP 1 00A. The Seikosha GP 1 00A uses a 5 x 7 dot matrix printing format with ASCII standard upper and lower case character set. Printing speed is 30 characters/second with a maximum width of 80 characters. The printer uses standard fanfold paper up to

Baseline s the most economical way to add memory to your TS-1000. It is fully compatible with Memopak 1 6K and 32K RAMs to provide you with up to 32K or 48K of RAM respectively. Memopak 1 6K RAM. The Memopak 1 6K RAM offers expansion capabilities through its “piggy-back” connection and is fully compatible with Timex or Memotech 1 6Ks to give a massive 32K of RAM.

Memopak 32K RAM. Offers your TS-1 000 a full 32K of directly addressable RAM. It enables you to execute sophisticated programs and store large data bases. It is also fully compatible with the Timex or Memotech 1 6K RAMs to give you a full 48K of RAM. Memopak 64K RAM. Turns your TS-1000 into a powerful computer suitable for business, recreational and educational use. No additional power supply is required. It accepts such basic commands as 10 DIM A (9000).

New Memocalc . . . push-button spreadsheet analysis. Allows the generation of a spreadsheet of up to 7000 numbers with up to 250 rows or 99 columns. Every time the command to calculate is given, all the numbers in the table are instantly re-evaluated.

Memopak HRG. The Memopak High Resolution Graphics, with up to 192 by 248 pixel resolution, enables display of high resolution “arcade game” style graphics through its resident 2K EPROM, programmed with a full range of graphics subroutines. Memopak Interfaces. The Memotech Centronics parallel or RS232 interface paks enable your TS-1000 to use a wide range of compatible printers. The resident software in the units gives the ASCII set of characters. Both Memopak printer interfaces provide lower case character capabilities and up to 8 column printing. The RS232 Interface is also compatible with modems and terminals.

Order at no risk! If you’re not completely satisfied, ■■BjiaiiHB return any Memotech product within ten days for a full refund. And Memotech's six month warranty means we’ll repair or replace any defective part free.

I1111'1"1 . To order, use the order coupon or call our

' toll-free number 800/662-0949.

Dealer inquiries welcome.

. - ,

Meul to: Memotech Corporation I 7550 West Yale Avenue • ™ Denver, CO 80227 i

Printer interface High Resolution Graphics | Memopak RAM

Peripherals that fit like a glove . . . for an integrated system look.

m&opm&m

‘All prices quoted in U.S. dollars. Prices and specifications subject to change without notice. “Please add an additional $5.00 for printer shipping charges.

16K RAM Baseline	$ 49.95
1 6K RAM	59.95
32K RAM	109.95
64K RAM	179.95
Memocalc	49.95
Keyboard with Interface	99.95
High Resolution Graphics	124.95
Centronics Parallel Interface	104.95
RS232 Interface	139.95
Printer Cable	19.95
GP 1 00A Printer Package**	399.00
Shipping and Handling	4.95	$4.95
Tax (Colorado residents only)
TOTAL	$	$

□Check DMasterCard DVisa

m CORPORATION^**

7550 West Yale Avenue • Denver, Colorado 80227 (303) 986-1 51 6 TWX 91 0-320-291 7

Account No. _ _ _ Exp. _ |

Name _ _ _ _ |

I City _ State _ Zip _ |

I Phone - Code: STX-03 I

I _ I

HARDWARE REVIEW

Product: E-Z Key 60 Keyboard

From: E-Z Key

Suite 75A

711 Southern Artery, Quincy, MA 02169 617/773-1187

Price: $84.95 plus $4 P&H

E-Z Key offers a 60-key key¬ board in a 10" x 4" x 1/2" black case that matches your ZX/TS. Each gray key is slightly concave, has a definite stroke and an audible click. Keys include the ZX/TS's standard 40 plus a numeric keypad, a second shift key, a 4 3/4" space bar and eight single stroke (no shifting) keys. The single stroke keys are FUNCTION, EDIT, DELETE, STOP, single quote, double quote, colon and semi-colon. Keyboard screening matches the ZX/TS leg¬ ends. Shift keys are red and match the red screening of the graphics and shifted characters. The func¬

tion key and function legends are yellow. Keywords, numbers and let¬ ters are white.

To install E-Z Key keyboard you must take apart your ZX/TS case, but no wiring is necessary. Gently remove your ZX/TS keyboard cables and replace them with the copper laminated cable that comes with the keyboard package.

E-Z Key's keyboard cable snaps easily in place and appears quite durable. It was the first time I had taken my ZX/TS apart and in¬ stallation took me five minutes.

My new keyboard worked perfectly as soon as I turned my ZX81 on.

I really like the audible click of the E-Z Key 60. I find the single stroke DELETE, EDIT, FUNC¬ TION and large ENTER keys very useful. I also use the numeric keypad and single stroke quote and semi-colon regularly. I found the keyboard easy to read and my entry time improved significantly. E-Z Key 60 Keyboard gave me a stronger psychological sense of "working with the computer."

I encoutered two problems with my keyboard. First, OR and STEP legends were missing from the key¬ board screening. Second, the back of the keyboard rocked slightly on the cable plug — not enough clear¬ ance under the keyboard. A tele¬ phone call to E-Z Key revealed that both problems were being fixed.

They volunteered to fix my keyboard before I could ask. E-Z Key also said they plan to make bolder leg¬ ends for punctuation marks and an improved instruction sheet.

I am pleased with my E-Z Key 60 keyboard. It is well designed, comfortable to use, is completely consistent with the style of my ZX/TS computer and improves entry. It's an excellent addition to your ZX/TS system that will help you to take advantage of all your comput¬ er's capabilities. I highly recom¬ mend E-Z Key 60.

Robert Masters, Tewksbury, MA

wmmxm is our tg as? you.

losTHurrr

'<**»»*»*

IMT€RCOMPUT€R IMC.

HARDWARE AND SOFTWARE PACKAGES

MAKE THE MOST OF YOUR TIMEX SINCLAIR 1000

MEMOTECH PERIPHERALS

MEMORY EXPANSIONS

16K RAM # PL7002 $ 59.95

32K RAM # PL7003 $109.95

64K RAM # PL7004 $179.95

HIGH RESOLUTION GRAPHICS (16K RAM)

# PL7007 $144.95

PLUG-IN KEY BOARD # PL7011 $99.95 CENTRONICS PARALLEL INTERFACE # PL7005 $104.95

MEMOTECH RS232 INTERFACE # PL7006

$139.95

PRINTERS

1 SEIKOSHA GP-100A PRINTER The revolutionary low- cost dot matrix impact printer— Uses up to 9.5” paper

# PL7008 $349.00

- SEIKOSHA GP-250X PRINTER The most intelligent programmable graphic printer— Uses up to 9.5” paper

# PL7009 $449.00

> PRINTER-INTERFACE CABLE # PL7010 $19.95 » MEMOCALC Software on plug-in EPROM cartridge— Spread sheet analysis— Up to 7000 numbers (when used with 64K) # BS200C $59.95

EDUCATIONAL ADVENTURE SERIES

EDUVENTURE I Answer the questions encountered in each classroom until you make it outside for RECESS and the surprise that awaits you there. (Grade level K-3)

# ED3001 $12.95

EDUVENTURE II Each new situation requires either your ingenuity or knowledge (or both) to avoid being sent to the principal’s office. (Grade level 4-6) i

# ED3002 $12.95

EDUVENTURE III Solve complex puzzles to outwit i

your teacher and achieve the highest scores. (Grade .

level 7-9) # ED3003 $12.95

EDUVENTURE IV An agile mind and quick reflexes !

will get you through this maze of mysterious situations- !

to your DIPLOMA. (Grade level 10-12) # ED3004

$12.95

All programs use 16K RAM.

NEW products coming soon: Software on ROM/EPROM CARTRIDGES— SOFTBOXtm . A software library which can contain several ROM/EPROM programs. Plug in your computer and instantly call any program from your SOFTBOX — A full line of software and peripherals for the "colorful ZX SPECTRUM/TIMEX SINCLAIR 2000.

For more information, Free Brochure, and Special Package Discount, write or call:

1C INTERCOMPUTER INC.

P.O. Box 90, Prudential Center Boston, MA 02199 Tel: (617) 437-1190 Telex: 951141 COFAR

QSAVE A Hardware-Software Combination— Allows a baud rate of 4000 to be achieved com¬ pared with only 250 on the normal SINCLAIR ZX81— Loads and saves a full 16K in only 29 seconds— Works with 16K and 64K. # PL7001 $37.95

Dealers and Distributors Inquiries Welcome

Mail to: Intercomputer, Inc., P.O. Box 90, Prudential Center, Boston, MA 02199







Shipping and Handling Printer	9.95
Shipping and Handling Memotech Products and QSAVE	4.95
Mass. Residents Tax	5% Total

□ Check □ Mastercard □ Visa

HOME MANAGEMENT

• BILL ORGANIZER Keeps track of bills, amounts due, date due, finance charges, payments made, etc. Sum¬ marizes all data for tax purposes. # HM5001 $14.95

• CHECK BOOK Balances and maintains your checkbook. Finds all checks written to one payee easily. Add a printer and it will even write checks for you.

# HM5002 $14.95

• ADDRESS BOOK Store, update and retrieve names, addresses, and phone numbers. With a printer attached, it will print mailing labels, sorts entries alphabetically by name, or by Zip Code. Only remember part of a name? It will find records from incomplete informa¬ tion. Code the entries for special purposes, i.e. Christmas Cards, Party Invitations, etc. # HM5003 $14.95

• OCCASION CALENDAR Keep track of birthdays, an¬ niversaries, meetings and special events. Have your calendar appear on the screen at the touch of a key.

# HM5004 $14.95

All programs use I6K RAM.

ENTERTAINMENT

•MISSILE LAUNCHER Challenge the enemy by destroying his ammunition stored in different locations.

# FG1002 $12.95

• KRAZY KONG A new version of the popular arcade game. This program has all the features of the original and is every bit as fast. # FG1013 $12.95

• GHOST HUNT Gobble your way through a maze of Ghosts, Power Pills, etc., etc., very fast. # FG1014 $12.95

• MAZE DRAG RACE Drive through a giant maze 9 times the size of the screen, watch out for other cars, rocks, oil and ice. A really superb machine code game. # FG1015 $12.95

• DEMOLISHER Design an intelligent strategy to demolish a growing wall before it crushes you.

# FG1005 $12.95

• MCODER Compiles a BASIC program into machine code— Extremely simple to use— Write and debug your Basic programs— Enter the MCODER— the Basic pro¬ gram will be compiled into machine code as you watch. # PT4001 $18.95

• RETURN FROM SPACE # FG1001 $12.95 •JEOPARDY # FG1003 $12.95

•VEGAS # FG1004 $12.95 •AIR ATTACK # FG1006 $12.95

• GUARD THE PRESIDENT # FG1007 $12.95 •SUBMARINE #FG1011 $12.95

• COMBO PACK I Contains Return From Space and Missile Launcher # FG1008 $18.95

• COMBO PACK II Contains Vegas and Jeopardy

# FG1009 $18.95

• COMBO PACK III Contains Demolisher and Air Attack

# FG1010 $18.95

• COMBO PACK IV Contains Guard The President and Submarine # FG1012 $18.95

All programs use 16K RAM.

Limited warranty— Defective Software will be replaced if returned within 30 days— Memotech Products: 180 days— Seikosha Printer: 90 days

MATH— 8K/16K

Use Math to introduce your children to the ZX/TS and give them experience with basic skills of addition, subtraction, multiplica¬ tion and division. Math provides 4 skill levels with 10 problems in a set. Students get 3 tries on each problem before getting an answer.

Use the mix-up choice to choose randomly among the 4 operations. Division is protected from remaind¬ ers, and subtraction never yields a negative answer.

Enter the listing in FAST mode, then switch your ZX/TS to SLOW and SAVE by typing RUN 100. Math self¬ starts and contains input prompts.

Inverse graphics are:

650 six graphic shift D 1120 graphic shift space 1130 graphic shift H 1140 graphic shift space 1150 graphic shift H 1240 graphic shift H, A, H, A

between words graphic shift H then repeat beginning sequence.

Barry Boyer, West York, PA

20 REM # MATH PRACTICE #

30 REM * BY B . L . BOYER *

SEM ***********************

50 REM

50 LET I=INT (D/E)

70 LET D=I*E 50 LET D $ =5TR$ D 30 RETURN 100 SHUE "MRTfflf"

10-* ^ "PLEftSE TELL

ME YOUR NAME 120 DIM G$(10)

130 INPUT G$

140 DIM B$(5,14)

150 LET B$ ( 1) /ADDITION**

150 LET BS 1 2) sr" SUBTRACTION"

JZ2 hEX (31 =" MULTIPLICATION" 150 LET B$(4) =“DIUISION**

190 LET B $ (5) ='*MIX -UP-

200 LET GUESS =0

210 LET R=0

220 LET U=0

230 RAND

24*0 CLS

250 PRINT "THANK YOU, **; GS; AT 1 j 1; *'NOU , PL ERSE SELECT**; RT 2,1;" 1- <+) BS ( 1) RT 3,1; "2. <-)

RT ^vi;M3. cx) **;b$C3);rt ?) *(51 ‘^B*<4);RT 6,1; "5. <

260'* IF INKEY* <>**** THEN GOTO 26© 122 XP^INKEEY*.— THEN GOTO 270 280 LET R* ss XNK EY*

290 REM * CHECK FOR URLXD ENTRY 300 IF CODE ft* <29 OR CODE ft* >33 THEN GOTO 2S0 310 LET SL=UAL R*

32© LET R=SL

330 PRINT RT 8,©; "YOU PICKED *’; ft; ** *•; B$ (R)

34-0 PRINT RT 10,0; "NOW PICK DIE FICULTY"; AT 11,0; "LEUEL 1 TO 4." 350 IF INKEY * < > " " THEN GOTO 35© 360 IF INKEY*-**** THEN GOTO 300 370 LET C * = INKEY $

380 IF CODE C* <29 OR CODE C*>32 THEN GOTO 380 390 LET C=URL C$

4*00 FOR K = 1 TO 10 4.10 FRST

4.20 IF SL =5 THEN LET RsINT (RND *4.) +1 4.30 CLS

4*4.0 PRINT RT 1 , 1; B* (ft) ; TRB 17;*’ LEUEL "; C; RT 6 , 10; "PROBLEM "; K 450 DIM D* CO 460 DIM E*(C)

470 IF C>1 RND R>=3 THEN DIM ES ( C - 1 )

480 IF 02 RND ft =4 THEN DIM ESC C— 2)

490 LET D*=STRS (INT (RND *9 999) +0>

500 LET E*=5TR* CINT C RND #9999/

510 LET D-URL D$

52© LET E=URL ES

530 IF D >E THEN GOTO 600

54© LET T*=ES

550 LET TEMP=E

560 LET E=D

570 LET ES=DS

58© LET D=TEMP

590 LET D$ — T $

600 IF (INT (D/E) OD/E) RND R*4

THEN GOSUB 60

610 LET T=LEN STRS D

620 LET 5=LEN STR* E

630 SLOW

640 IF ft <4 THEN PRINT RT 10,10- T; DS; TRB 10-5; ES; RT 12,5;" - ”

' 650 IF ft =4 THEN PRINT RT 14,5; " mmhm"; RT 15, 5— S; ES; AT 15,5; " J ** ; RT 15,6; D*

66© IF ft=l THEN PRINT RT 11,4; "

4“

67© IF ft =2 THEN PRINT RT 11,4; **

X"

68© IF ft =3 THEN PRINT RT 11,4;

690 PRINT RT 21, 0/ *

700 INPUT RNS

710 IF R=1 THEN LET CORftNS=D+E 720 IF ft=2 THEN LET CORftNS=D-E 730 IF ft =3 THEN LET CORRNS«D#E 740 IF R=4 THEN LET CORRNS=D^E 750 PRINT RT 20,0; "

RT 21,0; **

tt

760 IF CORRNS =RNS THEN GOSUB 9©

0

770 IF CORRNS < > RNS THEN GOTO 1© 4©

780 NEXT K 790 CLS

800 PRINT RT 1, I;B*( SL/; TRB 17; "LEUEL ** ' C

810 PR INT RT 9 , 1 ; G S; RT 10,1; ‘*|8S WSSS^y RT 12, 1; R; " RIGHT RND " ; W ; *" WRONG**

8

WHERE TO MOVE RAM TOP?

820 FOR 1=1 TO 30 330 NEXT X _

TSll 1R X|«iNjj RT — 1 11 “MHMi *■— M : &

f'iflT 21™ "ENTER CY) ES OR l 350 IF INKEY* < > " " THEN GOTO 35© 360 IF INKEY $=" " THEN GOTO 360 870 LET fi*=INKEY*

330 IF CODE ft $ =62 THEN GOTO 200 390 STOP

900 REM **RECOG. CORRECT ftNSUER

910 LET R=R+1

920 LET F*=STR$ CORftNS

930 LET U=LEN F$

94-0 LET GUESS =0

950 FOR J = 1 TO U _____

960 PRINT RT 18 , 20 ; "HHMEig&" ; ftT

970 IF ft 04 THEN PRINT ftT 13,18 -U; F$ CU-U+i)

930 IF ft =4 THEN PRINT ftT 13,6+T

~u; f$ cu-u+i>

990 PRINT RT 10, 20; "YOU RRE" ; RT 11,28; "CORRECT"

1008 NEXT U 1010 FOR 1=1 TO 15 1020 NEXT I 1830 RETURN

1040 REM * INFORM OF WRONG ftNSWER 1850 LET F $ =STR $ CQRftNS 1068 LET U=LEN F$

1070 IF GUESS =2 THEN GOTO 1260

1030 FOR U=1 TO U _

1890 PR INTRT1&, 20; ftT

11,20; "gnaagaaiag"

1108 FOR 1=1 TO 1118 NEXT I

1120 IF GUESS =0 RND ft<>4 THEN PR

TMT QT 1 ^ i uBm

1130 IF GUESS < > 0 RND ft 04 THEN P PINT RT 13 . 10-0; "M"

1140 IF GUESS=0 RND R=4 THEN PR I NT RT 13,6+T-U; "B"

1150 IF GUESS O0 RND ft =4 THEN PR INT RT 13,6+T-U; "$g"

1160 PRINT RT 10,20; "YOU RRE" ; RT 11,20; '• WRONG "

117© NEXT J 1130 FOR 1=1 TO 5 1190 NEXT I

1200 LET GUESS =GUES5+1 1210 PRINT RT 10,2©;" ";RT

11.20; "

1220 PRINT RT 13,20,* "YOU HRUE"; ft T 14,20; 3-GUESS; '* CHRNCES"

123© IF GUESS =2 THEN PRINT RT 14 , 28,* ";RT 17, 20; G$; RT 13,20; "TH INK HfiRDER"

1240 PRINT RT 21,0; "=

1250 GOTO 700 1260 LET U=W + 1 1270 PRINT RT 13,20;" T 14 , 20; " "

128© FOR J=1 TO U 1290 PRINT RT 10,20;" ” ; RT 11, 2© ; "| -

ft

1300 IF R O 4 THEN PRINT RT 13,1© ~J; F$ CU-U+1)

131© IF ft =4 THEN PRINT RT 13,6+T -J; F$ (U-d+1)

1320 PRINT RT 10,20; "THE CORRECT 51 ; ftT 11 , 20; "RNSUER "

1330 NEXT J

134© FOR 1=1 TO I©

1350 NEXT I 1360 LET GUESS =0 1370 GOTO 78©

3YNTRCT IC SUM: 53397, 8K ROM

Many programs that put machine code routines above RAMTOP tell you to lower RAMTOP first. This pro¬ gram calculates just what decimal numbers to POKE to put RAMTOP where you want it.

Enter the program as listed. Press RUN, then follow the prompts.

Richard Graffius, N. Versailles, PA

RAMTOP is a system variable that tells you where the computer thinks the top of memory is. You can change it to protect machine code (see SQ, Winter 82 p.20) or to reduce the available RAM. To cal¬ culate where to move RAMTOP, first figure out the standard RAMTOP for your memory size. Add the number of K of RAM you have to 16 (the ROM uses 16K bytes — 8K of instructions and an 8K duplicate) and multiply by 1024 (bytes per K). Subtract the number of bytes to reserve. Enter the answer as the address line 100 asks for. This program also gives you the most and least significant (MSB and LSB) bytes of the address you enter. — Ed.

10© PRINT "ENTER RDDRESS OF RRM TOP UftNTED"

110 INPUT MC 120 CLS 130 DIM H £45 140 PRINT

15© LET H (4) = INT CMC ,'40361 160 LET H C 3) =INT C CMC— H (41 *4096 3 .-256)

170 LET H (2) = INT CMC- C CH (43 *409 63 f (H(3) *256} ) /16)

130 LET H Cl) =MC- C CH C4) *4096) + CH (3 3 *256) + CH (2) *16) )

190 PRINT MC; ** = LSB . . " ; H (23 *16+ H ( 13 ; ** " ; "MSB . . " ; H (4) *±6+*f C 33

20© PRINT 210 PRINT

22© PRINT "FOR ft NEW RftMTOP OF

** j MC

230 PR INT

S40^ PRINT "POKE 163SS , " ; H C2) #16

25© PRINT "POKE 16389 H (4) *16

+H (3)

260 PRINT 278 PRINT

280 PRINT "THEN TYPE ""NEW"" RN D ""ENTER"""

29© PRINT RT 19,0; "TO FIND RNOT HER, TYPE ""RUN”""

SYNTACTIC SUM: 32243, 8K ROM

9

PLEDGE KEEPER — 8K

Pledge Keeper simplifies recording pledges and can be espe¬ cially helpful during telethons or other fund raising events.

It uses ID numbers instead of names, which are usually considered privileged information. Your data entry person doesn't need to know contributor's names and addresses but you can keep track of them for your pledge committee to use.

Enter the listing and RUN. Pledge Keeper asks for ID number, pledge amount, and kind of pledge (W for weekly, M for monthly, Q for quarterly, S for semi-annual or Y for yearly).

If you enter zero for a pledge, the program displays the ID number, and yearly amount of zero. Totals or averages won't use the entry.

After your last entry, enter a negative ID number and ENTER.

Pledge Keeper displays and totals all pledges, the number of people

64K MEMORY M-64 $119.9k^t

129.95 WIRED & TESTED IN STOCK. SAME DAY SHIPMENT All standard features included, plus lower 8K of RAM can be disabled in 2K segments to allow PROM or peripherals to be added.

EXPAND YOUR 16K SYSTEM

$59.95

If you have a Sinclair 16K RAM module and need I more memory, expand it to 32K and beyond by usinq [BYTE-BACK M-16 MEMORY MODULES.

You can’t connect two Sinclair 16K RAM modules together,

I but you can connect one Sinclair 16 K and one or more BYTE- BACK 16K modules to get all the memory you need.

THOUSANDS IN USE WITH PROVEN RELIABILITY

M-16 $59 .®5 Kit. $69.95 wired and tested.

IN STOCK. SAME DAY SHIPMENT

BB-1 Control ModlllG. with 8 relays, 8 leds

& 8 inputs. $59 Kit. $69 wire and tested. IN STOCK! SAME DAY SHIPMENT

95

MODEM with RS232 Port $1 1 9.Kit

$149.95wire & tested.

90-Day Warranty On All Modules. 10-Day Return Priviledge ORDER PHONE 803-532-5812

Add $4.95 shipping & handling to all orders.

BYTE-BACK CO. CHECKS

Rt. 3 Box 147 Brodie Rd.

LEESVILLE, SOUTH CAROLINA 29070 ■■■■L

who pledged, and gives the average annual pledge.

Edit lines 10, 30 and 40 to suit your particular needs or in¬ sert your organization's name.

Robert DeMunbrun, Rushville, IN

1 REM KEEPING TRACK OF PLEDGE S

2 REM BY R « M « DEMUNBRUN

3 REM INPUT ID NO . .. PLEDGE j KIN DCU FOR WEEKLY -M FOR MONTHLY -O F OR ©URRTERLY-S FOR SEMI -ANNUAL -Y

FOR YEARLY »

4 REM TO "GET TQTRLS AND AUERA GES INPUT NEGATIVE NUMBER FOR ID

1© PRINT TRB 10.1 "FIRST UNITED”

2© PRINT TRB 12; "CHURCH"

30 PRINT TRB 9; "PLEDGES FOR"

4-0 PRINT TRB 13; "1983“

4-2 PRINT

4-5 PRINT "ID"; TRB 5; "PLEDGE"; T RB 14; "KIND"; TRB 20; "YEARLY"

50	LET N=©
60	LET T =0
70	INPUT I
8©	IF I<0 THEN	GOTO 840
90	INPUT P
100	IF P=0 THEN	GOTO 550
110 120	LET N =N + 1 INPUT IF R$="W"
130	THEN	GOTO	600
140	IF A$="M"	THEN	GOTO	650
150	IF R$="0"	THEN	GOTO	700
160	IF R$="S"	THEN	GOTO	750
170	IF Rft="Y"	THEN	GOTO	800
550	PRINT I ; TRB	20;	P
560	GOTO 70
600	LET R=S2*P
81©	PRINT I; TRB	5; P	■; TRB	14; A$; T

A© 20; R 520 LET T=T4R

630 GOTO 70 ©50 LET A-12*P 560 PRINT I; TRB RB 20; R 670 LET T=T*R 600 GOTO 70 700 LET R=4*P 710 PRINT I; TRB RB 20; R 720 LET T=T+R 730 GOTO 70 750 LET A=2*P 76© PRINT I; TRB RB 20; R 770 LET T=T+A 780 GOTO 70 800 LET fi=i*P 810 PRINT I; TRB RB 20; R

5; p; TRB

5; P; TRB

s; P; TRB

5; P; TRB

020 LET T=T+R 830 GOTO 70 8»10 PRINT

850 PRINT “NO. PLEDGES";

14-; R$; T

14; A$; T

14-; R$; T

14; A$; T

TRB 13;

860 PRINT "TOT PLEDGES"; TRB 12; "$";TRB 13; T

870 LET U= (INT ( iT/NJ *100) ) /100 880 PRINT "RU PLEDGE"; TRB 12; " $ " ; TRB 13; U 830 STOP

SYNTACTIC SUM: 4394.. SK ROM

lO

TIMEX SINCLAIR 1000 SOFTWARE

SOFTSYMC, HMC.

METEORITES Shoot your way out of the asteroid field.

16K $14.95

NIGHTGUNNER Maneuver

your tail gun as you fire at enemy aircraft coming at you from all directions. Features on-screen scoring and bonus points. 16K $14.95

GRAPHICS KIT 16K GRAPHICS KIT 16K GRAPHICS KIT 16K GRAPHICS KIT 16K

GRAPHICS KIT Machine

code routines to help create exciting graphics in programs.

16K $14.95

m

A

RED ALERT 16K

RED ALERT Scramble between treacherous mountains and fearsome aliens.

16K $14.95

SPACE RAID/

TS DESTROYER Two great

fast action 2K programs on one tape. 2 K $14.95

HANGMAN Seven versions of this classic guessing game including a user creaTed library of 500 words. 16K $14.95

ALIEN INVASION The best

TS/ZX version of this classic game. 16K $14.95

2K GAMES PACK 6 great graphics games on one cas¬ sette: COPTER PATROL, KILLER WHALE, ASTROWALK, MONSTER MASHER, STAR BLASTER,

DRAGON SLAYER. 2K $14.95

ALPHA/ VOWEL TUTORS

Two graphic tutorials designed to teach the alphabet as well as long and short vowels.

16K $14.95

MOTHERSHIP Zoom down

the Zarway corridor, dodging and shooting drones, to get a clear shot at the ominous mothership. Amazing graphics!

16K $16.95

PROGRAMMERS TOOLKIT 16K

PROGRAMMERS TOOLKIT Machine code

routines to help programmers write better software.

16K $14.95

MATH RAIDERS Teaches

children basic mathematics through the use of a graphic game. 16K $14.95

ADVANCED BUDGET

MANAGER Stores a year's worth of projected and actual income and expenses.

16K $16.95

THE STOCK MARKET CALCULATOR two

programs to aid the investor in calculating stock and option investments. 16K $16.95

SPACE COMMANDO

This adventure takes you to Zircon 12 to overcome the alien forces and liberate the planet.

16K $14.95

SHARK’S TREASURE m

this adventure brave the deadly shark infested waters to find the treasure. 16K $14.95

THE ADVENTURES of "QUEST FOR THE HOLY GRAIL" and "THE ELUSIVE MR. BIG"

Two different adventures on one tape. Special feature creates new versions every time.

16K $17.95

SUPERCHESS The most

advanced chess available featuring ten levels, tactical or positional analysis, self play, and will recommend moves.

16K $19.95

MAZOGS The most

elaborate, graphic maze adventure available for the TS/ZX computers.

16K $19.95

BIORHYTHMS Chart your Physical, Emotional and Intel¬ lectual ups and downs.

16K $14.95

Write or call for free catalog and program listing.

SOFTSYNC, INC., 14 E. 34TH ST., NEW YORK, N.Y. 10016 (212) 685-2080

DEALER INFORMATION AVAILABLE MCIVISA ACCEPTED

DEAR EDITOR

I bought and highly recommend the two-tone Keyboard Audio Tone from TV Services of Cambridge LTD, Chesterton Mill, French's Road, Cambridge CB43NP, UK. Keyboard Audio Tone costs $18, is very well made, compact and easy to install (five solder connections).

I mounted an oversized heat sink on the right of the standard heat sink and it works fine. I also added an on/off switch in the black (ground) lead.

Keyboard Audio Tone tells you when a key is hit, when your ZX/TS accepts it and is ready for more input — very handy on long text lines in SLOW mode. It also sig¬ nals the beginning and end of SAVE or LOAD, PAUSE and INPUT prompts.

Sidney Linton, Dunwoody, GA

For those readers who want to add a full-sized keyboard, I recom¬ mend Double H. Electronics, 195 Lelan, San Antonio, TX 78242.

I bought a keyboard from them two months ago. I installed it with no knowledge of electronics or its complexities. With the aid of Mr. Hornung of Double H., I now have a full keyboard with shift lock, repeat, +, -, *, comma, ;, =, DELETE and EDIT on separate keys.

Double H.'s keyboard (11" x 4") is excellent in quality and has a clean design. All my queries were answered with dispatch, knowledge and patience. Double H. provides service that is uncommon today.

Complete assembled keyboard, with plans for additional circuits is $46. Parts for additional cir¬ cuits are $13.

William Mitchell, Ontario, Canada

I've been trying to program a game that accepts input from two players simultaneously. When I use INKEY$ function and two keys are depressed at the same time, the

CODE INKEY $=0. This creates a problem. Is there any way I can get around this using machine lan¬ guage? Maybe a hardware modifica¬ tion would help?

Randy Thompson, Eugene, OR

Write your own ML keyboard scanning routine. Use ROM routines, modi¬ fying codes to suit your purposes.

Ian Logan's ROM Disassembly, Part A, details the keyboard scan routine at 02BB as well as other keyhandlers. Briefly, eight half¬ rows of the keyboard, connected by diodes to address lines A8-A15, see a series of numbers with just 1 bit high. Each key connects 1 address line to 1 KBD line so the processor can get a bit set by column and row of the active key. Eight scans put a number in the HL registers. The monitor decodes characters in a ROM table. No hardware needed. — KO

Is it possible to adapt pro¬ grams to save on tape so they can be read and run on a Sinclair sys¬ tem in England (and vice versa)?

My brother in England has a ZX81, and we'd like to communicate through them. I understand the problem is in transfer of data to the graphic display because of differences in the number of lines on British television systems. Can it can be overcome?

Wendy Roberts, Cambridge, MA

We bought many tapes in London and they work fine. Unless you use MC to manage the display file your¬ self, like Quicksilva's Defenders game, you should encounter no prob¬ lems. If you use PRINT or PLOT to put messages or designs on the screen the differences in TVs are irrelevant. — KO

I recently opened my TS1000 case to install heat sink grease on the voltage regulator to dissipate heat more effectively. In the process.

12

I unwittingly damaged the keyboard leads; however, I did manage to salvage my computer.

Opening the case of your ZX/TS can be hazardous to your computer. You can damage the keyboard leads with a kink or tear. So when you open the case, first disconnect the leads by gently pulling the flat plastic cable out of its sockets at the PC board front.

If the leads are damaged, you can salvage them if the damage is near the PC board and the conduct¬ ing strips are exposed on one side of the plastic. Leads are actually longer than required so carefully cut them to just below the damaged section and trim off the excess plastic. Your TS1000 will work as good as new after reinserting the leads into the PC board connectors.

John Reinhardt, Madison, AL

As noted in SYNTAX'S Aug. 82 review of Memotech's 64K Memopak, the pack causes screen interference when mounted on the computer. The trouble seems to come from a poor ground-bond between the board and its aluminum case.

To solve these problems, I carefully drilled a small hole in the side of the pack to the right of the switch hole then mounted a self-tap screw. I attached a short lead to the screw and soldered it to a ground point on the ZX/TS board and brought it out the expan¬ sion hole corner nearest the screw. This change cleared up most screen interference.

Most remaining noise resulted from a poor ground (0V) bond be¬ tween the modulator box and main board. After resoldering, my dis¬ play is clean.

Jon Harder, Concord, MA

Much of the problem of poor RAM pack contact with the edge connec¬ tor seems to result from pried module contacts when you push the

pack on too tightly. Swab both sides of the connector with TV con¬ tact cleaner/lubricant and slide the pack on and off several times. Then insert it all the way and back it off about 1/8". (Partial inser¬ tion can cause wobble and other bad contact problems. — KO)

Another cause of ZX80 only key¬ board lockups (Jan. 83 Dear Ed.) is the keyboard membrane over a parti¬ cular key area may sag slightly from continued use and heat. As long as one key is not breaking contact when released, none of the other keys will work. Sometimes a patch of heavy transparent tape over the troublesome key area will "bridge" the membrane enough to lift it from the contact traces beneath it.

However, if a key doesn't make contact), carefully lift the key¬ board membrane and clean both mem¬ brane conducting area and contact traces with a Q-tip moistened with alcohol. This works if only one or two keys are involved. If a half¬ row of keys stops functioning all together, it's usually a sign of a poor solder connection at a key¬ board diode or resistor, especially on some of the earlier ZX80 boards.

Robert Hartung, Palmyra, NY

Can I create a user-defined graphic symbol for the ZX/TS? I have done a lot of ML programming lately, but cannot find in the ROM disassembly what part goes to the graphics table for lookup and then causes the 8-byte symbol to print to the screen.

Clement Wehner, Scott AFB, IL

Yes, you can buy sprites by the ROM (try Integrated Data Systems, 11 Brighton Ave., Toronto, Ontario, or dk'tronics, 23 Sussex Rd., Great Yarmouth, Norfolk, UK). Check our big character programs (Jul.82 and 4K modification, Aug. 82) to see how to read the ROM character set. — KO

13

BOOK REVIEW
Title:	Computers For Kids — Sinclair ZX81 Edition
By:	Sally Greenwood Larsen
From:	Creative Computing Press 39 E. Hanover Ave. Morris Plains, NJ 07950 800/631-8112, 201/540-0445
Price :	$4.95 (softcover, 64pp.)

Perhaps you justified buying your computer by your children's need for computer literacy in this day and age. This book is a first step toward a child's computer literacy. It offers both incentive and instruction during a child's first few weeks with a ZX/TS. Af¬ ter reading this book with a ZX/TS nearby, he or she is on the way to being a pint-sized programmer.

Computers For Kids — Sinclair ZX81 Edition is valuable as a stand-alone course or a teacher's guide. It proceeds slowly and logically from "What is a Compu¬ ter?" to computer operation to simple programming techniques.

I couldn't judge whether the text was too ambitious or repeti¬ tive for children, so I asked my eight-year old. He worked through the book and reports it "taught me a lot about computers and games and what it can do for you and stuff." (I think he found it entertaining, informative and instructive.) He also pointed out a couple concepts I missed in the manual, showing real understanding of BASIC funda¬ mentals. I was impressed by what this book taught him.

But I feel Larsen spends too much time on computer operation and not enough on programming. She could have more profitably used the sections on operation to reinforce newly acquired programming skills.

Still, if your under-14 chil¬ dren know nothing of BASIC and microcomputers, this book is an important investment.

John Connell, Middletown, RI

DIRECT INPUT HORIZONTAL AND VERTICAL LINE GRAPHICS — 8K/1K

Horizontal and Vertical graph¬ ics lets you draw lines by direct input and loops so you can draw until you run out of memory.

Line 10, INPUT A$, selects the type of line you want to draw- horizontal or vertical.

For horizontal lines INPUT A controls the Y-pixel coordinate, INPUT B controls the beginning X coordinate and INPUT C controls the end X coordinate.

For vertical lines, INPUT A controls X-pixel coordinate, INPUT B controls the beginning of the line, and INPUT C controls the end of the line (Y-pixel coordinates).

After you enter the listing, press RUN and "L" appears. Press H or V to select the mode and ENTER. The L cursor appears again — enter coordinates A, B, and C one at a time and your ZX/TS will draw the line. To stop, hit STOP and ENTER twice. Try this example which draws a small rectangle (hit ENTER after each mode and number):

1) Select H mode and press 9, 4 and 13. Select H mode again and hit 4 , 4, 13.

2) Press V for vertical mode and hit 4, 4, and 9. Select V again and hi t 13 , 4 , 9.

Lawrence K. Simmons, Riverside, CA

18 INPUT ft*

3© IF THEN GOTO S©

30 IP THEN GOTO 130

4.0 GOTO 1©

5© INPUT ft 8© INPUT B 7© INPUT C 8© LET Y*ft 9© FOR X=8 TO C 10© PLOT X / Y 11© NEXT X 12© GOTO 1©

13© INPUT ft 14© INPUT B 15© INPUT C 18© LJET Xasft 17© FOP YeB TO C IS© PLOT X,.Y 19© NEXT Y 20© GOTO 1©

SYNTftCTIC SUM: 14097.. ©K ROM

14

REAL-TIME SOFT CLOCK

You can get a real-time clock through hardware or software. The hardware option, while usually more reliable (especially with battery backup), costs about $60 with special purpose chips (M3M 5832). Software clocks are cheaper.

Soft Clock creates a software clock from the 3.25 MHz ZX/TS logic clock using the system variable FRAMES at decimal addresses 16436 and 16437. FRAMES tracks the num¬ ber of pictures sent to your TV (60/second in the US). Soft Clock keeps track of the value of FRAMES.

Soft Clock should be accurate to a few seconds/day. It requires just less than 2K RAM. You can use it as a subroutine in application programs. Just make sure you GOTO 200 at least every five minutes (actually about 8.8). The severe limitations are:

1. You can't turn off your compu¬ ter, even for a second.

2. You can't use FAST anywhere in your program (FAST resets FRAMES to 65536) .

3. You can't use PAUSE.

Line Functions:

Line Purpose

7 F (fudge factor) corrects for internal clock. Value between 0 and 2 works best.

8 Initializes the count.

100 Looks at current FRAMES.

211 Checks that FRAMES isn't in

to the middle of a bit manipu- 215 lation. If it is, ignore

the count this time.

220 Resets starting count if

FRAMES rolls over from 32768 to 65556.

230 PINC is change in count.

250 SS is value of seconds.

Same for MM, HH.

340-74, 600 Pretty up output.

392 Print time at 4,20.

920 Lets you start clock at

any time you want.

960 Lets you set time.

P.J. Donnelly III, Centerport, NY

1 REM SOFTWARE CLOCK

6 CLEAR

7 LET f=1.605

8 LET OU =32768

9 GOTO 9©@

100 LET C=PEEK 164-36 4256 *PEEK 1 6437

105 RETURN 200 GOSUB 10©

210 LET NU=C

211 IF OU<NV THEN GOTO 215

212 GOTO 220

213 REM

215 IF OU>NU-256 THEN GOTO 200 220 IF OU < Kv THEM LET QU=OU+3£7 88

23© LET PINC=ABS C (OU-NU1 +FJ 24© LET GU=NU 250 LET SS =3S fPINC /60 260 LET M INC =0

27© IF SS > =60 THEN LET MINC-INT (SS/60)

280 LET S5=5S-MINC*S0 290 LET MM =MM +MINC 300 LET HC =0

31© IF MM >=60 THEN LET HC=JNT i MM 760)

320 LET MM=MM~HC*60 330 LET HH=HH+HC

340 IF HH >24 THEN LET HH=HH-24 370 IF HH < 10 THEN LET H$ = ,*0"

372 IF MM <10 THEN LET M*="0"

374 IF SS < 10 THEN LET Z$="0"

390 LET SS1=INT S3

391 PRINT AT 2,20;"

392 PRINT AT 4 , 20; H$+STR$ HH+" : "*M$+STR$ MM+" : "+Z*+STR* SSI

410 GOSUB 600 499 GOTO 200 600 LET H* = ""

602 LET M* = ""

604 LET Z$ = ""

607 RETURN

900 PRINT' " SOFT CLOCK

901 LET P INC =0 905 PRINT

92© PRINT "SET TIME (S) OR STAR T AT © (Z) "

930 INPUT 5*

935 CLS

940 IF'‘S$ = "Z" THEN GOTO 950 942 IF S*="S" THEN GOTO 960 944 GOTO 93©

950 LET SS=-4 952 LET MM=0 954 LET HH =©

956 PAUSE 0 958 GOTO 200

960 CLS

961 PRINT "ENTER TIME AS HH: MM!

SS”

962 LET P INC =0

963 INPUT T*

965 IF LEN T $ < > 8 THEN GOTO 953

966 LET MINC=0

967 LET HH=URL T* tl TO 27 96S LET MM=URL T*C4 TO 5) 969 LET SS=URL T* (7 TO 8) 971 PRINT "IS THIS RIGHT?

“ . Ir ; MM; " . " ; 55

973 INPUT S*

974 PAUSE 0

975 CLS

976 IF 5*0 "Y" N GOTO 200

OR 5* < > "YES** THE

978 GOTO 961

SYNTACTIC SUM: 15979, 8K ROM

15

GET YOUR SYSTEM TOGETHER

Your ZX/TS is compact but can give you that "all over the place" feeling with snarled cables, loose RAM pack problems, and instability.

One easy, but expensive, cure is an encased keyboard that holds your ZX board inside.

This cheaper way doesn't take much time and uses materials you may already have:

1) 10" x 16" shelving, 3/4" thick.

2) Double-stick transparent tape.

3) Four-inch foam mounting tape.

4) Adhesive-backed felt.

5) Rubber selfstick 1/2" squares.

6) Neon nightlight, 1/4 watt.

7) Extension cord (in-line switch) .

Raise your ZX/TS with four new feet to make it more stable when typing. This also raises your RAM pack, reducing risk of crashes when typing shifted characters.

Next, place your ZX/TS with RAM, printer and power pack on the board in a pleasing and simple layout. Coil up the 9V DC cord and leave just enough to reach your ZX case. You can turn your ZX/TS on and off with the AC cord switch.

Check your system layout for convenience and find the shortest wire length for each connection.

Use foam tape to mount the power pack with its prongs to the back so you can bring the extension to it easily. Plug the night light into the end and use a side connection as the AC supply to the pack. When the power is on, the light is on.

Pass the cables under your computer to neaten up your system's layout. Put double-stick tape on each new rubber foot and position your ZX/TS where you want it- — press firmly until secure. Mount your printer the same way.

One more plus: a 10" x 16" board fits inside many attache cases, so you can travel with your whole system. A few bucks gives your ZX/TS dignity.

Jon Harder, Concord, MA

SOFTWARE REVIEW

Program: Snake

Price: $9.95 plus $2.50 P&H

ROM/RAM required: 8K/16K Printed listings? No Program listable? Yes Written in: BASIC and MC Challenge: Great

Display: Good

From: ZETA Software, POB 3522

Greenville, SC 29608

You are a snake in this game trying to maneuver inside a barn and eat mice that randomly pop out of holes. This would be easy if you didn't have to worry about your length increasing with every mouse you eat. The game ends when you touch the barn walls, cross your own path, or eat 100 mice.

Snake comes well packaged on tape with instructions and two sets of stick-on labels for the direc¬ tion keys. Snake loads easily and runs automatically.

Two user-selectable variables give Snake thousands of game com¬ binations, although most are sense¬ less as the instructions warn.

These two variables are the snake's speed and length of time the mice freeze when they pop out of their holes. The score, which increments with every mouse you eat, is con¬ tinuously displayed at the bottom of the screen.

My only complaint about Snake is the top display line is slanted. I think this is because the display is generated by machine code. This line does not affect game play and adjusting horizontal hold control on the TV helps. (Jon Bobst of ZETA says the slanted line could be due to a MC generated display, the TV or hardware used — Ed.)

Snake provides many hours of recreation and becomes a challenge trying to beat your last score.

It's also compatible with all ZX/TS 8K ROM machines.

John Impellizzer i , Sterling Hts, MI

16

HOW

IT^M I/M I A a A ATI/MT KA

An ELECTRONIC FILING SYSTEM that can be used for ANY type of data. Set up your own DATA-BASES with this easy to use, menu-driven program with AUTO-SEARCH facility. * 4ARfl

ORDER No. 03-1021 *l!r,u

BREAKOUT

Fast MACHINE CODE arcade-type game. If you haven’t tried THIS version, you haven't played “BREAKOUT” on the ZX81/TS1000. * * -oc

ORDER No. 03-4028 * l4a5

‘M’-Coder™

Creations Inc. — d/b/a Computer Discount Services

Draw and store complex images. Permits you to create, mix, and save your own screen artwork. You can mix graphics created with GRAFIX into another program. By itself or on tape. This program is a “must” for the CREATIVE PROGRAMMER.* 4 4nc ORDER No. 03-6005 5 1495

Now you can write MACHINE CODE PROGRAMS on your ZX81 with ‘M’-Coder. The first true MACHINE CODE COMPILER for the ZX81 Computer. Simply write your new program in BASIC, (or load an — =EXISTING PROGRAM), press A-KEY and ‘M’-Coder will automatically compile it into MACHINE CODE for you. ‘M’-Coder codes 99.9% of all BASIC. Give all your programs that SUPER-FAST professional look. Order ‘M’-Coder NOW to revolu¬ tionize your programming. Once you try ‘M’-Coder you’ll never write basic programs againl Cjaqr ORDER No. 03-5201 * 19

EXR DATE

MO

YEAR

Superb fast moving MACHINE-CODE fun. Have an exciting time playing this EXCELLENT version of the popular arcade game. * 4 iaR

ORDER No. 03-4027 * |430

VISA

CHARGE

□ □

INTERBANK NO

Sign

Ybur own PERSONAL OR SMALL BUSINESS ac¬ counting system. Contains refinements not usually found in this type of program. “200 Transaction file” can be SEARCHED, PRINTED or DISPLAYED. This program has been throughly tested, and improved through extensive use. * 4onc

ORDER No. 03-1022 $ 1995

NAME

ADDRESS

POWER AT YOUR FINGER TIPS!

ORDER No. 01-0007

KOPAICS “TOUCH-A-MATIC” gives you the power to type more accurately and faster. It requires NO WIRES, NO SOLDERING. It’s as easy as removing the adhesive backing and pressing it into position.

Sub-lotol

Add sales tax

CITY _ STATE ZIP

up to $9.99 to $14.99 add$2.00 from $15.00 to $19.99 add $2.50 trom $20.00 to $24.99 add $2.85

from $25.00 to $29.99 add $3.45 from $30.00 to $39.99 add $3.70 from $40.00 to $49.99 add $3.95 over $50.00 add $4.25

$995

Pocking Sr Shipping (See Chart)

Ibtal amount enclosed or to be charged to my credit card

Enables you to play any tune through your T.V. speaker, your cassette recorder or through an A.M. radio. With ‘COMPOSER’ you can control the dura¬ tion of each note. And you can save your song on

ORDER No. 03-3012 $1995

ORDER FORM

TO AVOID DELAY PRINT CLEARLY STOCK NUMBER AND DESCRIPTION

TOTAL

AUTOFILE

PUCKMAN

QSave

LOADS & SAVES 16 K file in 26 seconds instead of 7 minutes! Cleans up signal for a cleaner load.

• STRONGER, SHARPER DIGITAL SIGNAL

• CLEANER, FILTERED POWER • ENCODES YOUR PROGRAM AND/OR DATE • Save time/Save i

• Baud rate increases from 250 to over <

must for all ZX81/TS1000 owners. TM * a fine ORDER No. 04-1000 *09yo

DO OR DIE — 8K/16K

You are trapped in a Mayan maze-like tomb. A block pixel in the central chamber is the only escape route. Use arrow keys 5,6,7 and 8 to move but watch for trap doors that send you back to the starting point. An hourglass timer along the right side of screen relentlessly spills away, starting with the first move, so keep going. Breaking walls or enlarging doors disqualifies you.

Use a larger value in line 110 to increase your game time. Press RUN to start and BREAK to exit.

Tom Shields, Franklin, NC

2 REM LINE 110 CONTROLS TIME 5 REM "S" SAUES "DO OR DIE"

10 REM L310 A320 SET "TRAPS"

15 FAST 20 GOTO 2000 50 SLOW 55 PAUSE 500

60 IF INKEY*="S" THEN SAUE "DO OR DI@"

70 PAUSE 40000

Sinclair

Computing

Not just another newsletter, Sinclair Computing is a typeset magazine with color illustrations, published monthly. If you own a Sinclair or Timex/Sinclair Computer you need Sinclair Computing. Every issue is packed with informative Articles, New Products, Users Groups, News Bits, Letters, Ask Sinclair Corp., Reviews, Tutorials, Hardware Projects (many for under $10), Programs, and Games.

FOR JUST $2.95 PER ISSUE

YOU CAN MAKE THE MOST OF YOUR SINCLAIR or TIM EX/ SINCLAIR COMPUTER.

If after your first issue you are not fully satisfied. ..cancel your subscription for a FULL refund.

Sinrlair

Lomputing

□

I want one year for just $36.

I want two years for just $65.

Enclosed is my check or money order.

Sinrlair

Lomputing

NAME _

ADDRESS

BOX 95 SC

Glenmont. New York 1 2077

CITY _

STATE _ ZIP

125 LET X =2 130 LET Y —2

135 PLOT X . Y

136 PLOT X . Y 140 UNPLOT X,Y

150 7	IF	INKEY$="	5"	THEN	LET	1 X II X
180	IF	INKEY $="	6"	THEN	LET	y —v -
~ 17© 3.	IF	INKEY $="	7"	THEN	LET	Y=Y +
IB©	IF	INKEY $ = "	8"	THEN	LET	x=x +
' 190 310 Y = 12	LET IF OR	Z=Z + i X =26 AND Y X =26 AND	= 4 OR Y =27	O EX li XM	6 AND =26 R

350 IF Z =L THEN PRINT AT T.. 31;"

5100

500 GOTO 135 1175 LET A=A+4 1130 LET B =B -4 1135 LET C=C-4 1200 GOTO 2050 2000 LET R-0 2010 LET B = 56 2020 LET C =43 2050 FOR X=A TO B 2060 PLOT X..A 2070 NEXT X 2500 FOR Y=A TO C 2510 PLOT 8,Y 2520 NEXT Y

2700 FOR X=B TO A STEP -1 2710 PLOT X.. C 2720 NEXT X

2300 FOR Y=C TO A STEP -1 2310 PLOT A,Y 2020 NEXT Y

2325 IF A =16 THEN GOTO 3630

2350 GOTO 1175

3680 LET X =26

3710 FOR 0=27 TO 39 STEP 4

3715 UNPLOT X,0

3720 UNPLOT X.,Y

3725 NEXT O

3730 NEXT Y

3805 LET Y =22

3810 FOR X =4 TO 52 STEP 4

3815 UNPLOT X,Y

3820 NEXT X

4000 FOR 1=0 TO 21

4-040 PRINT AT 1,31;

4045 NEXT T

4050 PRINT AT 10,10;" DO NOW"; AT 11, 10; " OR DIE"

5050 PRINT AT 10, 10; “YOU DIE"; AT

11,10;"

5©55 STOP

5110 PRINT AT 10,10; "YOU WIN"; AT

11,10;"

SYNTACTIC SUM: 29469, 8K ROM

STX-3

18

REVERSE VIDEO MONITOR DRIVER

This circuit, using the concept published in Electronics (6 Oct. 82 p.113) , drives a video monitor and reverses video on demand. You can get all parts except 74LS266 chips at Radio Shack. Many parts stores carry 74LS266s — we paid $0.60 each.

Caution: SYNTAX considers this

circuit developmental. It may need adjustment or design change to work with a specific computer and compo¬ nents. Use it as a place to start.

With one chip, one 2N3904 and 10 discrete components, the circuit offers a simple, low-performance solution. Just connect video, +5V (30 mA drain) and 0V to your ZX/TS to drive a Zenith ZVM-121 monitor.

Build this device on a small experimenter board. Keep the wires short and use coaxial cable for the video connections. Lay the 2N3904 flat against the board, insulate the circuit, and fit it under the ZX/TS PC board. Or make 5V from

the monitor's 12.7V supply and put the circuit inside that case.

Standard video signals switch between 3 signal levels: white and black (video) and sync (blacker- than-black). Usually, picture sig¬ nals rest at black, drop regularly to sync level, and rise to white. ZX/TS video rests at white, drops regularly to sync and dips to black to create character dots.

We must separate the sync from the video pulses, standardize the video to switch between black and white levels, and make sync pulses flip from video to sync levels.

We use LS exclusive NOR (A OR B AND NOT BOTH) gates. LS chips take voltages above 2 volts as logic highs and voltages below 0.7 volts as lows. If both inputs are +5V or both are 0V, output is high (+5V). Leaving an input open or tying it to +5 gives equal logical results.

So when the ZX/TS signal drops from white to black, the gate does not respond, while white to sync

+5V

IC1 74LS266

19

transitions change the gate output state. In our circuit, pin 5 takes composite video input and compares it to 0V on pin 6. Pin 4 responds by being at +5 for sync inputs and 0V for video. We obtain combined horizontal and vertical sync at pin 4, but with levels reversed? we correct these with the 2N3904.

Pin 9 also gets the combined signal, but compares it to a lower voltage signal that stays <0.7V at ZX/TS black level, but goes high at the white level. Both inputs are low at ZX/TS sync level. These in¬ puts differ only during the black level, so pin 10 follows video.

Pin 13 gets a reference signal of +5 or 0V to choose the voltage at pin 12 which will cause a high voltage at pin 11 (video output).

Output resistors and diodes create a new composite video sig¬ nal. When pin 4 goes to +5V, the 2N3904 brings the output to zero — the sync level. When pin 4 is at 0V , pin 11 controls the output between black and white levels. — KO

THE PEOPLE'S

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No soldering, plugs into edge connector 010 SE I KOSH A GP100A DOT MATRIX PRINTER. . 325.00. . 425.95* SE I KOSH A GP250X DOT MATRIX PRINTER. . 369.95. . 469.95*

‘Parallel Printer Package Includes Cable & CPI In terface

VISA, MASTER CARD & AMEX & MONEY ORDERS

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01 ZONX 81 SOUND

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Requires Direct Video Mod to ZX81 FREE Plans with order, simple in stallation

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THE PEOPLE S COMPUTER SUPPLY P.O. Box 664, Sidney, Nebraska 69162 Order Phone: Tel. 308-254-3208

SOFTWARE	REVIEW
Product:	Reference Card for the ZX30 , ZX81 and Timex Sinclair 1000
From:	Nanos Systems Corp. P.O. Box 24344
	Speedway, IN 46224
Price :	$5.95

"This card has it all!" ex¬ claims Nanos System's advertising. And indeed it does. Reference Card for ZX80, ZX81 and TS1000 comes in a handy 3 3/4" x 8 1/2", 20 panel, accordian-f old format. The card is packed with information such as brief descriptions of the BASIC statements, commands, operators, and functions.

Among its many tables and charts Reference Card also has: screen layout, character codes in decimal and hexadecimal, error codes, memory maps for the ZX80, ZX81 and TS1000, and selected ZX81 ROM calls. Reference Card even has tips on how to use FOR. ..NEXT and IF. ..THEN statements.

These features alone make it worth the price. But if you're an assembly language programmer (or want to become one) you need this card. One side is a virtual cornucopia of assembly language information. It summarizes in¬ structions for: math, storing registers in memory, loading registers, moving memory to memory, exchanging, shifting, comparing, branching, data alteration, and I/O. . Tables of flags, conditions, and instructions which set flags and a handy hexadecimal/decimal conversion chart are also included.

This is a reference card, not a tutorial, so don't expect it to provide step-by-step instruction.

If you are fairly proficient with your ZX/TS, this card will save you the time and energy it takes to thumb through manuals — you won't want to be without it.

20

James Conrad, Seattle, WA

ROUTINE ELIMINATION — 8K/1K

Machine Language programs often use BASIC routines to load REM lines with ML code. If you PEEK the code from the REM line and POKE into protected memory for running, you can eliminate the loading rou¬ tine by writing the REM line in hex equivalents to ML decimal codes.

You have to initialize REM lines to use in the loading routine anyway, so why not just write it in hex and skip the routine and all its decimal inputs? Published rou¬ tines usually list the hex with the ML program, but if not, you can get it in the Appendix of the ZX81 or TS1000 manual.

This example uses the 8K Syn¬ tactic Sum decimal listing (Jun.83) converted to hex.

Before typing or loading the program, regardless of memory,

POKE 16388, 225

POKE 16389, PEEK 16389-1 and NEW to reserve memory space for the ML routine. The 225 in the POKE is derived by subtracting 1/2 the num¬ ber of characters (31) from 256.

Now enter the listing as shown. Type SAVE, RUN and write down the displayed value. Then PRINT USR the value to get Syntactic Sum.

(In line 4, 16574 comes from adding the number of characters in the REM line (62) less 2 to 16514.)

Line 2 gets the first address of reserved memory, which will be the starting address of the ML rou¬ tine. Line 5 PEEKS hex from the REM line, converts it to decimal, and POKES it to reserved memory.

Rolf Miller, Ventura, CA

1 REM 217D40ED5B0C4-0DD2 100007 eBfl20087DBB2004DDE5GiC34E0600BB0 3231 SEC

2 LET R=PEEK 16388 +PEEK 18383 *256

5 PR INT ft

4 FOR X =165 14 TO 16574 STEP £

5 POKE ft, CREEK X-2S) *16+PEEK (X + l) -28

6 LET ft-ft + 1

7 NEXT X

SYNTRCTIC SUM: 11175, 8K ROM

CLASSIFIED ADS: Reach almost 10,000 ZX/TS users for $9/line.

Send ad copy, 35 char. /line with check to arrive by 15th of any month. Include your tel. #, wheth¬ er or not it appears in ad. SYNTAX RD 2, Box 457, Harvard, MA 01451.

***** KAMIKAZE *****f or ZX81/TS1000

* +16K; NEW sensational game of *

* SKILL from DC SOFTWARE... ONLY *

* $6.95 incl cassette, supply ltd *

* Box 928 Richmond VA 23298 *******

//2K Programs from 2-BIT SOFTWARE/ / //"Making Treks" $9.95. Free // //catalog games/educational soft-// //ware. 2-BIT SOFTWARE, Dept SY2 ,/ / //PO Box 2036, Del Mar, CA 92014//

' ' ' ' ' ZX SUMMER CAMP Give Kids The SINCLAIR Advantage 1 to 6 wks. All levels, ages 9 to 18 Details $1, SASE (ref undable) , NEW WORLD CONCEPTS, Bx 587 , Ogden, UT844 02

i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i

MARBLES. MAZES AND SINK HOLES A simple, non-destructive game of skill and logic for all members of the family. 15 levels of play, from very easy to extremely difficult, each with 4 different screen types giving 60 full-screen displays. Score displayed as time taken; auto clock enforces time limit; auto run and return to basic features. 100% machine code program for ZX81 or TS1000 with 16k RAM. Cassette $15. CHARLES DRURY, 40 WESTGATE RD #5. CHESTNUT HILL , MA 02167 '

- look FOR -

- INTEGRATED DATA SYSTEMS -

End Gliches/Loading Problems. SASE: Programs , 3763 W Crocus ,Phx,AZ 85023

Turn Sinclair's ROM or your machine code into assembler mnemonics with "DAI". Tape/instr $9. Martin Irons 46 Magic Circle Dr, Goshen, NY 10924

FREE 1 2 programs on tape. SASE to: Programs ,3763 W Crocus ,Phx,AZ 85023

21

** 15 ELECTRONIC DESIGN PROGRAMS **

* ZX81/TS1000 IK cassette $9.99 ***

* BRICK SOFTWARE PO Box 1455-X ****

* Bricktown, New Jersey 08723 *****

*** 60 Programs for ZX81/TS1000 *** Each month get 10 programs on tape. Games , Home , Bussiness , Utility f Educ.

6 months $19.99f 12 months $34.99 =========== BRICK SOFTWARE==========

PO BOX 1455-X BRICKTOWN, N.J. 08723

- OK you Hosers! The computer

drinking game has arrived! Can you become the new "BEERMASTER" ? 1 Eh?

— ORCAVISION: #408, 10139-117 St. Edmonton, Alberta, Can. T5K 2L3 For TS1000/ZX-81 (16K) $14.99 US.

GUESS MY NUMBER-2 players vs comput er. Uses names and keeps score. Listing — $0. 60/stamps. M. WILLIAMS, BOX 1445T, EAST ST LOUIS, IL 62201

ZX81/TIMEX 1000. ..FINGERS SLIPPING? Improve accuracy, speed input, feel you keyboard with a "ClearTouch" overlay. No modification reqd. Easy to install. $9.95 + $1.50 SHP, CHK/MO Visa/MC give exp. date. CT, Dept 40 PO Box 1136, Anacortes, Wa. 98221

ZX81/TIMEX-1K GAMES-5/$1.95-8/$2.50 "Sector Attack" ,"Star fighter", more. KEN DOGGETT, 3436-H Fairway Oaks Dr Lawrenceville , GA 30245

**** TECHNICAL APPLICATIONS **** Software for electronic CAD and formulas. All in BASIC, on tape, with comprehensive instructions. Send SASE for a list of programs and prices to: Softec, P.0. Box 432, Fairport, New York 14450

SINCLAIR/TIMEX INTERFACING TO ANALOG and DIGITAL Devices. J.V. Kane And Co. 109 Ardmore Avenue, ARDMORE Pa 19003. 215-649-1782

******T IMEBLASTER s****** A 1.7K M/L ARCADE GAME FOR SERIOUS Players. For ZX81/TS1000 (16K RAM) Send $12.95 To: CALLIOPE SOFTWARE 4130 COE DR NE, ALBUQ. , NM 87110

*** THE DEFINITIVE TAX PROGRAM *** Fr 16K ZX81/TS1000. EASY DATA ENTRY AUTOMATIC TAX COMPUTATION FOR EACH CHANGE, INCLUDING INCOME AVERAGING. Inf o:SASE , Cassette:10.95. ** LOP 2365 Newcastle, Cardiff ,Ca, 92007 **

- ZX/TS 16k NEWCOMER SET

I MT-SOFT ! Cassette & Listings ! TEACHER ! AMORTIZATION . . $6.95

i - 1 print-BIG . . . $7.95

MT-SOFT, Bx 2638, Aurora II. 60507

YOU CAN UNLOCK REAL COMPUTING POWER wtih new KEY — now expanded to give: UNLOCK-SAVE any ZX/TS cassette prog PROTECT-move a program above ramtop MERGE-join ramtop & workspace progs BYTE-show # of ram bytes remaining. Short ML tape with USR calls $10PPD in US/Can. G. Russell - Electronics RD 1 Box 539, Centre Hall, PA 16828

MULTI-FUNCTION WINKY BOARD II**New SAVE filter cuts rampac "noise" for clean easy loading tapes. DUPLICATES any ZX/TScassette. SAVE on 2 cas¬ settes at once. Solves LOAD problems AND MORE! Tiny lxl 1/2" openboard interface needs no power no mods $24PPD $18Kit G.Russell-Electronics RD 1 Box 539, Centre Hall PA 16828

***** ZX81 - TS/1000 SOFTWARE ***** ENTERTAINMENT - EDUCATION GAMES - TEXT ADVENTURES - BOOKS Send For Catalog & FREE Game Software Unlimited PO Box 147 Grandview MO 64030

ZX81 Program: "RECIPE RETRIEVAL" Store 200 recipes; sort, search, & LPRINT routines - $19.95 ppd. USA ck/mo CARRIAGE SYSTEMS, BOX 2066 TOLUCA LAKE, CALIF 91602 - 16K +

Drive a video monitor with your ZX- 81. Our DVC-1 direct video kit is only $9.95. With the DVC-2 you can switch select normal or REVERSED video. Kit $20.45, fully assembled $31.45. Get super sharp character definition with our 12" B&W video monitor, only $98.45. Random Access Box 41770S, Phoenix AZ 85080

22

COMPUSETTE is a C-10 cassette which is especially designed for micro¬ computer application by TAPEMASTERS 25 for $20.00 100 for $70.00

COMPUSETTE + is a C-20 cassette 25 for $22.00 100 for $77.00

VISA MASTERCARD C.O.D.

TX 214-349-0081 **OTHER 800-527-1227 10% Discount for Check with Order P. 0. Box 38651*Dallas , Texas 75238 FREIGHT PREPAID*DEFECTIVES REPLACED

OUR POLICY ON CONTRIBUTED MATERIAL

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 prompts.

• 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.

**FREE GAME PROGRAM! ISend Stamped** *Envelope To:ZAMIS ENGINEERING, 251* **First St . , Per rysburg ,0hio 43551**

SINCLAIR & MICROACE (8/16K) Utility 5K bytes of subroutines:

Base conversions-Binary-Decimal-Hex

Plot Circles & ASCII Code

Arctan-Radians-Degrees

Read addresses in Dec.& Hex

Memory remaining- 404-445-6544

M-WARE-Rt . l-Hiram,Ga. 30141

VISA & MASTERCARD-ppd.U.S.A. $11. 95

LEARN DATA HANDLING TECHNIQUES with ZX Data Finder, a versatile file manager for 16K ZX81s. All routines thoroughly explained. Concepts and dozens of memory saving methods are analyzed. List/text $9.95-free info Tom Woods Box 64 Jefferson, NH 03583

********** DOUBLE-UP ********* Merge 2,3 Or More Programs In Secs. Listing $1, Tape $5. G.D. Forsythe RD #1 Box 277A Landenberg PA. 19350

"PERSONAL FINANCES-PART I" for 8 Compound Interest Calculations & "PERSONAL FINANCES-PART II" for 8 IRA & Simple Interest. LISTINGS $7.95 ea TAPES $12.95 ea S&H $2. SEE, BOX 787, Fallbrook, CA 92028

SYNTAX is published

monthly by a wholly-owned subsidiary of The Harvard Group.

Syntax ZX80, Inc.

RD 2, Box 457, Harvard, MA 01451.

Telephone 617/456-3661.

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

Publisher: Kirtland H. Olson Editor: Ann L. Zevnik Assistant Editor: Pamela Petrakos- Wilson

Editorial Assistant: Pamela K. Vinal

YES! Please send me 12 issues of SYNTAX for $29. 3/83

□ My check for $29 is enclosed. □ Please charge my □ MasterCard Make checks payable to: □ Diner’s Club □ American Express

SYNTAX ZX80, INC. □ VISA □ Carte Blanche account

account number _ _ _ _ _

exp. date _ bank number (MC only) _ _

signature _ _ _ _ _

Name _ Title - - -

Organization - - -

Address _ _ _ _

City _ _ _ State _ Zip -

Day Phone_( _ ) _ Evening Phone_i _ ) _

I own a □ Sinclair ZX80 □ Sinclair ZX81 Telephone orders call

□ TS1000 617-456-3661

23

SYNTAX

INTEGRATED DATA SYSTEMS 11 Brighton Av Toronto Ont M4M 1P3 Your 1 stop for AUDIOGRAPH, Bi-Pack BYTE-BACK, DEAN, DATA-ASSETTE, EZRA GRP, GRAPHICOMP, INTERCOMPUTER, IPS, KAYDE, MEMOTECH, OASIS, RIST,ORBYTE SINLCAIR, SIMULSION, SOFTSYNC, TIME¬ WORKS, ZODEX,eg4K Graphics ROM$76.10 Graphics Space Invaders $14. 90, FULL AUTO REPEAT module $34.50,16K PANDA RAM $63.60 (can+16K inside it) Star Battle $24. 20, Home Inventory $18.70 Money Manager $24.20,ZXChess2$29.80 RIST PARROT voice synthesizer $129, Min ord $25 W/MO+$1.50 P&H. Outside CDN less 2 0 % (30% Home, Star , Money) & Send that amt as US$. Ont res+7%PST Deliv 5wk ARO. FREE 300 item list.

***********RC0 technical***********

Z-WRYTER-Word processor. Write, edit, save text using powerful editing functions. Supports ZXpr inter .Great for notes, reports. $9.95

DISTACALC-Calculates great circle distance and azimuth between any 2 points on earth using lat/longitude File area holds 200 cities. Great for hams-remar kably accurate. $11.95 Tape&manual-16K req.Add $1 postage. RCO PO BOX 773D ST ANN MO 63074

35X26 ELECTRONIC WORKSHEET 16K $10! SASE brings MFREEM Program & Cat. EZRAEZRA, Box 5222 , SanDiego CA 92105

TOPNOTCH! Keeps running charts on up to 20 stocks (16K) TAPE, INFO-$5. 50 to EDBSOFT,Box 22,Keuka Park, NY 14478

*********************************** WIN A MINDWARE MW100 ZX/TS PRINTER Send SASE To:MMl Comp. ,YAGSEE,

PO Box 155 , Vicksburg , MI ,49097 .

'k'k-k'k-klc'k'k'k'k'k'kic'kic'k'kic'klc'k-k'k'k-k'k'k'k'kic'k'k'kic'k

HAM RADIO LOGGING PROGRAM — ZX-LOG Clock-calendar automatically logs time & date. Search by any combi¬ nation of items. Ex: Find all Utah QSO's who owe you a QSL. Additional records can be used for notes. 16K will hold 90 records, 48K-850. SASE for info. $35 postpaid. Send call. PSION ZX-CHESS (16K) mod. Save and restart in mid-game. Print Screen. Instr. $2 + SASE. Dennis Hevener, 1721 1/2 Holly Dr., Glendale, CA 91206. Telephone (213) 246-3265.

PAKGUY-Our version has power capsls full screen maze,ghosts&FAST ACTION ML ASTROIDS-8 directions;every rock splits 3 ways. Cass. w/both 16K games &ML-S7.FREE CAT. MILL RESEARCH 32749 Avalon Cr . Abbotsford, B. C. Can. V2T3W9

**CASH JOURNAL GENERAL LEDGER for

small business - $9.00

**REMEMBER & DOTTODOT games - $4.00

To : DGC POB1642 Roswell, GA 30076

HARVARD

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