Home

Sinclair User - Retro Computer Resource

1. ZX CHESS Crete Woy now only 9 95 option ADVENTURES COR aim onde ganan s ene tome cn on Ya he a oU re a el as ADVENTURE B in a jungle clearing you come across an Inca temple ADVENTURE c Sows GALAMANG maaa tanen a nachina 20805 tees woi ma desti 7 00 access to ali registers and to search through and modiy memory w and many more For a catalogue giving fi Artic Computing Dept 396 James Reckitt Avenue Hull HUB OJA details please send a S A E t KEMPSTON MICRO ELECTRONICS ZX KLIK KEYBOARD 44 isa stylish and ergonomic plinth for the ZX81 It raises and tilts the TV to avoid eyestrain holds the 16 in place and hides the wiring and power supply This very professional unit costs 15 a built in power switch is 3 plus postage at 1 50 inc VAT Peter Furlong Products 125Catford Hill London SEG 4PR Callers by appointment please Tel 01690 7799 Visa Access SINCLAIRUSER July 1982 Accounting for small business TWO sophisticated ac counting programs have been put on to the market by Hestacrest with the in tention of improving the efficiency of routine ac counting at low cost The programs are writ ten for preparing accounts from incomplete records of a sole tr
2. ADULT p UNIVERSITY OF MANCHESTER INSTITUTE OF SCIENCE AND TECHNOLOGY SACKVILLE ST MANCHESTER SATURDAY 24 10 30 21 00 SUNDAY 25 10 30 18 00 JULY 1982 Free draw for MICRO compete Clud Stands Being sad Bey stall Fess parking Review of Biaclaie 8pectium Lectures small micro applications Free Films Bar sad eefheshments Clogs to ceates aad Piccadilly ststion Fees Coffee Facilities the Dissdled WS ADMISSION CHILD under 16 half price with coupon r for all users BUFFER MICRO SHOP NEXT TO STREATHAM STATION NEW SOFTWARE SHOP EXCLUSIVELY FOR ZX81 PROGRAMS GAMES ADD ONS MOST OF THE MAIL ORDER ITEMS ADVERTISED IN THIS MAGAZINE AVAILABLE OVER THE COUNTER LOADING PROBLEMS TRY OUR INTERFACE BUSINESS amp TECHNICAL DATA HANDLING PROGS PROPER KEYBOARDS CONSOLES VDUS 374A STREATHAM HIGH ROAD LONDON SW16 Tel 01 769 2887 S A E APPRECIATED FOR CATALOGUE ZX81 amp 80 OWNERS ACCESS TO THE OUTSIDE WORLD SPECIALISED PRODUCTS MODULAR EASY TO USE FOR HOME INDUSTRY amp EDUCATION EU PORT _ Easy 1o use Fits betonen ZX amp RAM PACHPRINTER red No shi Yo conne ten es v mor dort e t 9 ROS TN AILSA 240601104 way Teansiston 58
3. Please Debitmy HAG 52 00 7 80 VAT 59 80 Access Barclaycard A complete range of ZX81 plug in peripherals accountnumber Packaging amp Postage 2 00 per unit Centronics Interface amp Software Drivers TOTAL ENC Digitising Tablet RS232Interface Please delete whichever does app We regret we areas unable to accept signature CM products but you know AME DONE E as they become available TELEPHONE Soe We want to be sure you are satisfied with your Memopak so we offer 14 money back Guarantee on our products Memotech Limited 3 Collins Street Oxford OX4 1XL England Tel Oxford 0865 722102 Telex 837220 Orchid 1 wobbles MUCH has been written on the subject of RAM pack wobble little of it giving any sound advice as to how it may be prevented I feel that the three solutions which I have found are the best to date TheSinclair RAM would be as good as any other except for the fact that it does not appear to be very eager to stay on the computer and will jump off when any key is touched hard enough 1f you have 2 to spare you buy a ribbon cable and solder one end to the RAM and plug the other to the edge connector of the PCB That means that when you hit a key too hard all that happens is that the ribbon cabl
4. prefixes or even the total distances over which the contacts were made Keeping the score is an ideal job for a computer which can also log each call sign and display message if a station has been con tacted previously in the contest On the technical side there is a vast number of uses for the ZX 81 Two examples are aerial design when the computer can be used to work out the dimensions of an aerial fora particular frequency and even to calculate its theoretical perfor mance and the design of electronic circuits American magazines publish pro grams of that nature frequently Those programs are usually written for the most popular home com puters in the U S such as the TRS 80 but it is fairly straightfor ward to convert them to run on the 7X 81 the main differences being that the TRS 80 does not require the word LET in an assignment state ment and that it allows multiple statements on one line Another popular application is Oscar tracking Oscar stands for Orbital Satellite Carrying Amateur Radio It is a satellite designed built and paid for by radio amateurs and launched by NASA on their behalf The satellites pick up amateur transmissions on one frequency and re transmit them on another allow ing communication over distances which might otherwise not be possi ble To use Oscar it is necessary to know where it is at any given time and so a program can be used to predict when the
5. KEY 2 380 PRINT STOR 3 TERM SELECTION 390 PRINT KEY 458 e 20 422 PRINT 424 436 PRINT KEY 2 aD PARA RES 1999086099695 ui manmanan aa NIMEONA 88988696 OM d 3 90007 EET Mn 2 zn LE MA OR ADDING MORE SLID OR SAVING PROGRAM OR CHANGING PROGRAM IN SLIDE See 650 1300 1500 HAS T THEN GOTO soo ER cope SLIDE 5 JOHN RECIOR FLETCHER us 2 C THEN au ARE THERE MORE 5 D THEN 3 These Be me ae esee es SOsuB Ae esten wi Quer anm ise similar scatter to dis hidden secret 2 han mble dis disse abs dissemble CLAIRUSER July 1982 Daniel Shavick of 10 PRI 1 2 136 12 5 E ICT pus London Sheepdog a dif A9 LET ficult game which is good e representation of a sheepdog trial 8 ter A sheep an inverse S is driven by 58 LET dog an inverse D through a gate 28 LET denoted by two black squares and 9e PRI SH SL CHR 184
6. SINCLAIRUSER July 1982 POOTBALL MANAGER eddictive Games AS MANY SEASONS AS YOU LIKE 4 DIVISIONS __ PROMOTION amp RELEGATION FULL LEAGUE TABLES amp TRANSFER MARNE INIURIE XZLEVETS OF PLA x SAVE GAME FACILIT NC ES TRS80 VIDEO GENIE 1 5 y MANAGERIAL RATI PICK YOUR TEAM FOR FACH MATCH w 1 WE GUARANTEE that this i ever planed BUT BEWARE HARDWARE REQUIRED Video ik ROW Lk RAM LEVEL MILTON KEYNES MKH INE KAM Professional Grade Keyboard and Case at Unbeatable prices 3kOur case takes the ZX 81 pue Sinclair makes the best home computers and we make the best keyboards STAR BUY Mail Order Address Pleas ad GORDON ELECTRONICS Mabe che 76 Mountbatten Road cor Braintree Essex CM7 6TP Telephone 0376 26048 SANDERSON SOFTWARE 1 3 programs on one tape Crame your own yout Vocabulary feature Sor Search Dele Your own Detabani change Data by Cursor Select Many Serous Uses Job Work Programming MultipieIndesing Diaco Music Library ae 2X Adventure Tape Y 500 Greedy Gulch Pharaohs Tomb Mage Mountain 18K RAM required Atom Business t695 ledger pius much more 2XB1 Pocket Book Cassone 600 Atom Business Cassette 8 62 order Phipps Associates Mat Order Dept F
7. Phone Access Barclaycard orders Epsom 03727121218 MANSFIELD COMPUTERS ELECTRONICS 79 Gate Nor NG 1820 Phone 0623 31202 of GENIE ATOM 20 sccenaoren b books SPECIAL OFFER XB PRINTER PAPER TOP QUALITY roe tor ony 10 98 ie VAT pb EDUCATIONAL SOFTWARE 2X87 11007 GCE LEVEL FRENCH 3 rtm rar pus IN programs ASTRO INVADERS 16K Superior machine code programming last ction spece graphics ew henson in ZX 8 valve on screen bin ettect continuous score and high score On cassette with four BONUS pamen ARCADE GRAND PRIX machine code Wi 4 levels PENALTY get ready for Spain 82 GOLF judge shot stength angles bunkers and maybe hole in one plus tun SWAT 5 games on one cassette tor oniy 2 68 gost Wee Order now trom John rere mente vetesse VAT LAST a serious pe SAILING ant Er Eu i on Exe Eus perpe EEBEE Computer Wares 2 81 COMPUTER 16K RAM in superb condition all yours for only 100 o n o Phone 01 462 1614 after 2x81 16K RENUMBER Re number your program lines in cluding GOTO s and GOSUB s us ing this general purpose utility routine Recorded twice on high quality AD C46 cassette 3 50 all inclu
8. JRS SOFTWARE 19 WAYSIDE AVENUE WORTHING SUSSEX BN13 3JU TELEPHONE WORTHING 65891 Evenings and Weekends only 16K RAM PACK ALL FOR ZX8I SOFTWARE S DIGGLES 7 SIMPLE SU PPERS CELEBRATION DINNERS VOLUME 1 S OF WORLDWIDE RECIPES an VOLUME ES EUROPEAN RECIPES 99 inc P amp P and VAT Special price for two volumes 9 inc P amp P and VAT More volumes to follow MICRO COMPUTER SOFTWARE Unit 06 Pear industrial Estate Stockport Road Lower Bredbury Stockport SKS 28 Tel 061 494 2441 SINCLAIRUSER July 1982 TASWORD WORD PROCESSING ON THE ZX81 Your ZX81 becomes a word processor with TASWORD Type ir letters documents and pictures store them on tape and edit and update existing documents With a printer which is not essential you can print your documents TASWORD FEATURES INCLUDE OVER 300 LINES of text in a text file CURSOR CONTROL and auto repeat on all keys SCROLL up and down through the text file UTOMATIC word wrap and right justification FULL 2X81 character set including inverse characters and graphics symbols e INSERTION AND DELETION of lines and characters A HELP PAGE onto the screen at the touch of a key O CENTRE text on the screen and move text left and right REFORMING of edited text to a neat layout with a single TASWORD TUTOR send you manual and a cassette One side contains TASWORD The other side co
9. into a pen which is shown as grey DH DL z Ta sL 29 square The dog is moved upwards EXE THEN ODT by pressing O key downwards 110 LET Sz5 1 by key left by 1 and right by 3 Siete ee eee TEEN EET It continues moving until the S is 130 IF THEN GOTO 120 RINT AT DH DL CHRS 0 SH pressed SL CHRS When the dog is within five 156 PRINT AT 19 g9 CH36 138 _ 160 LET gt squares of the sheep sheep 52 DH 0 begins to move The difficulty is that i7OMLET DL DL RS CHR 31 AND D the movement of the sheep tends to L482 29 ANS DER a c be as wayward as any sheep in a LIDL gt Z THEN GOTO real trial 198 IF ABS DL SL Z THEN LET L SL4 SL gt DL 80 898 iE DH SH XZ THEN LET SH SH gt OH SHxDH 10 LET SH SH SH 1 cH 20 After a good deal of concentration the sheep can be penned and the time taken is 819 CET is OUED 81 88 displayed As guide it took our GF sH 18 AND 5556 SL gt 10 701 seconde 3 THEN LET SH SH reviewer 1 079 seconds one 218 eG second short of 18 minutes 1966 PRINT AT 21 0 5 SECONDS The game can be re started by 1849 484 pressing NEW LINE RUN SINCLAIRUSER July 1982 37 E INCLUDE special ZX 80 It is a version of the well known game of Mastermind where four n
10. wor EDUCATIONAL 1298 EE INDICATOR UNIT EDUCATIONAL 1295 JOYSTICK FREE GAME Jot may be connected via Motherboard 1298 1 00 MOTHERBOARD Allows muttpies combinations of add ons ines may mes 11598 50 ROWER SUPPLY 61 0v 300 mA requved or use ih addons TELS Zi WAY Di Ege Con 5 2 30 6 WAT SINGLE SIDED EDGE CONE 95 EXTENDED 10 NOTES TI Exhibition and other diversions for 2X B B C Micro VIC TRS Sharp es provided Deve rta rect ADU iwi lo ai orders under Sorcerer Video Genie Tangerine Nascom Atari Pel and Acorn user EB hh pon seme ti ag con Ful ban cmp e a ub ge 40 SINCLAIRUSER July1982 The popularity of writing in machine code is growing Phil Garrett looks at the systems which can help Aids for speed and efficiency Space Invader type arcade games for the ZX 81 and of books such as Toni Baker s Mast ering machine code on your ZX 81 it seems the ZX 81 owners want not only to run machine code programs but write them too That is scarcely surprising considering the tre mendous speed and efficiency of a machine code program compared to Basic but there is a trade off involved by the popularity of I wrote a three dimensional Noughts and Crosses program for my ZX 80 which played a good game but had a response time of 45 seconds A year later I wrote the same program in machine code on
11. MK High Res Graphics 16K Space Invaders 1K Wk RAM gt 0000 LI wOwoOmw tme Were DO 48 25 oe FA Assembly Assemb 3 8 1 00 No hardware medications whatsoever m SAE for catalogue programs supplied on cassette with instructions Send remittance with order Cheque P O Card No to MAGROMIGS Dept U quality games and special techniques PELA the widest range available from one supplier Mes 965 16 SINCLAIR USER July 1962 from J K GREYE SOFTWARE THE EU GENERATION SOFTWARE HOUSE Without question the finest machine code games available today ROWLAND Product Manager for W H SMITH GAMESTAPE 1 for Games inl ASTEROIDS GUILLOTINE KALEIDESCOPE exc PROBABLY THE BEST VALUE Tk TAPE AVAILABLE UFO CODE BOMBER We ve done in 1k games which some of our competitors P vov can NI the eram PYRAMID Car you move the Pyne Make a matane and ARTIST Tho ultenate Graphic Designers aid 8 Directons 10 Memories SAVE COPY RUBOUT CLS sc Inve can contar up to 9 Rooma 8 Passager 7 Monsters Food Gol Traps Pronome wh Exit ic Wa next Wve ercllnt gore which wil you amused forroun COMPUTER VIDEO GAMES Maze The DOT Were bur thon o T AEX and i after Y
12. City State Zip A Best explanation seen P fhisisa mus im Best independent oval package for the ZX81 MACHINE LANGUAGE MADE SIMPLE FOR YOUR 51 Syntax Magazine said I s the best explanation of Machine for Machine Language beginners I ve seen Its friendly style is painless reading and simple analogies help make this language clear This introduction is must Available os a quality paperback pages 9 75 including post pack ond VAT UNDERSTANDING YOUR 2 81 ROM by lan Logan Dr lan Logan was the 1981 winner of the Rosetta Stone Award given to the best independent product software package or application for the Sinclair ZX8O or 2 81 for his perceptive insights info the way the ZXB ROM operates This book explains ZX8O Machine Language in terms of the ZX8I ROM giving numerous examples of routines from the ROM and explains the structure and organisation of the ROM including routines from the ROM you can use yourself special section explains how to use machine code routines in your own BASIC programs CZ Available as a quality paperback 64 pages 975 including post pack e and ZX81 ROM DISASSEMBLY PARTS A amp Dr Logan is also the author of these two titles see above which are an invaluable source of information for the serious 2 81 Machine Language programmer Part A lists all locations and subroutines in the ROM from OOOOH to OF54H and covers
13. Range of in out ports music boards motherboards D to A converter boards write for catalogue 23 Way double sided gold female edge connector wirewrap type 2 95 Male connector 1 25 Ribbon cable 1 40 per metre Mastering Machine code book 5 50 Programming for real applications 6 50 Tape for real applications 11 25 HARRIS amp LOCKYER ASSOCIATES Sole distributors for Redditch Electronics Dept SU Prices included VAT 33Pedmore Close Overseas add 1 80 postage Woodrow South Delivery 3 days for in stock Redditch items else allow 28 days Official orders welcome Send sae for free catalogue Worcs Tel 0527 24452 ZX Software SCREENKIT1 MORE POWER TO YOUR SCREEN BORDERS any size any SCROLL in ALL FOUR dirt FILL SCREEN ar hic or character CLEAR and REVERSE ART OF SCREEN any part FLASHING CURSOR anywhere on screen simulates INPUT DATA FILES CIT LEER and MEMORY LEFT Mer EN gioia suono INSTANTANEOUS SCREEN RESPON e Cane iode toe er SUPERB VALUE 5 70 ZX MC MACHINE CODE DE BUGIMONITOR Atlast COMPLETE FREEDOM FROM BASIC tor machine code programmers vete ety commands or Hes de ma ESL rections OSPLAY REPOS Stoke on caste wt cae ma e SAVE LOAD VERIFY AT DOUBLE SPEED from any part of RAM cvata PaP SPECTRUM REM LOAD MACHINE CODE ENTRY DE BUG EX rrr taae Ba ns 6 95 EET E
14. complete with comprehensive instructions The cassette 655 which the game is supplied is of highest quality 500 and loading is guaranteed ALL PRICES INCLUDE POSTAGE is available kom Bug Byte and most good mm e mm mm mm mm 8 send me computer shops at 10 inclusive pe mpm ey dae Dosing Arii AOSS BARCLAYCARD ORDERS WELCOME ON SU 7 82 ANSAPHONE GS 227 2602 BUG BYTE SOFTWARE FREEPOST No stamp req 100 The Albany Old Hall Street Liverpool g LIVEREOGLISSAB wm am ZX81 B B C MICRO VIC 1 1 1 Code I 1 1 Nigel Clark Consultant editor Mike Johnste Production editor Hareld Mayes Design William Scolding Advertisement director ion Horgan Editorial dir John Sterlicchi tor Advertisement manager Les Mortos Editorial production assistant Margaret Hawkins Managing director Terry Cartwright Chairman Richard Hease Sinclair User is published monthly by Publications Ltd It is not in anyway connected with Sinclair Research Ltd Telephone All departments 01 359 7481 If you would like to contribute to Sinclair User please send typed or beautifully handwritten articles or programs to Sincla
15. on pane 56669 LET B DRIUESSIM 8 16 Bs5 26 2543 229 n 200 0 3 THEN R of attempts have been made to put the game of the ZX 81 and this Baines of Ashton under Lyne ire is a simple Version played on 16K memory When the program is run hole appears at the bottom of the screen and the player is asked to supply the angle of shot between 0 and 90 degrees and the strength fi usually greater than f the shotisshown onthe SINCLAIRUSER July 1982 SINCLAIRUSER Tuly 1982 R BRINT AT PRINT PRINT AT PRINT AT 9 9 0 gor ERAI os 400 e QR 290656061 vg N for attracting bugs in programs to emerge with their hands up but game in which the aim is to tempt bugs to fall into a swamp Tostart the press RUN and shown in one part of gs at random position m in one corner The plus sign is the bait ds which the bugs move involves moving the plus sign from corer to corner Tsing the cursor keys above 5 108 80 that the bugs fall into the swamp Once one of the bugs falls in the game stops and the length of time taken is shown If you wish to continue with the same lay out press the CONT key If BAITER is not took kit The gam and D Hayes of G 350 PRINT
16. Lik Professional Grade Keyboard and Case at Unbeatable prices case takes the ZX 81 printed board Keyboard supplied XYour Ram Keyboard No soldering Large ke keymarker lair makes the best home computers and we make the best keyboards Sin clude V 16 Ram ready built and in a case Uses existing power supply BUY 28 00 Mail Order Address Pease add 1 50 P amp P GORDON ELECTRONICS Make cheques va 76 Mountbatten Road GORDON ELECTRONIC Braintree Essex 7 6TP Telephone 0376 26048 SINCLAIRUSER July 1982 THE EXPLORER S GUIDE To The ZX81 The Book for the ZX81 Enthusiast By Mike Lord 120 pages Programs for 1K RAM and programs for 16K RAM Games Business and Engineering Applications RAM amp 1 0 Circuits Useful ROM Routines Hints and Tips Mat Can 1 Do with 1K The ZX80 Magic Book Mastering Machine Code on your 2x81 ORDER ENHANCE YOUR SINCLAIR ZX81 Video Inverter adds professional touch Displays sharp white characters on solid black background TV screen A toggle switch lets your choose between NORMAL and REVERSE NEW ONLY 5 ORDER NOW P amp P incl small printed circuit board fits on top of the logic chip inside your ZX81 Comprehensive easy to follow step by step instructions make the modification a simple task For convenience print you
17. Robinson Crusoe Which novelist do you associate with Father Brown Cassette E2 Fun to Learn series English Literature 2 ICL Hardware required ZX81 16K Price 6 95 Programs Poets Playwrights Modern Authors Description Who wrote Song of the Shirt Which playwright also played cricket for England series Geography 1 ICL Haraware required 2 81 16K RAM Price 6 95 Programs Towns in England and Wales Countries and Capitals of Europe Description The computer shows you amap and a list of towns You locate the towns correctly Or the computer challenges you to name a pinpointed location Cassette E4 Fun to Learn series History 1 ICL Hardware required ZX81 16K RAM Price 6 95 Programs Events in British History British Monarchs Description From 1066 to 1981 find out when important events occurred Recognise monarchs in an identity parade Cassette E5 Fun to Learn series Mathematics 1 ICL Hardware required ZXB1 16K RAM Price 6 95 Programs Addition Subtraction Multiplication Division Description Questions and answers on basic mathematics different levels of difficulty Cassette E6 Fun to Learn series Music 1 ICL Hardware required ZXB1 16K Price 6 95 Programs Composers Musicians Description Which instrument does James Galway play Who composed Peter Grimes Cassette
18. THE FIRST exhibition for ZX users to be held in Bir mingham is attracting a great deal of interest despite its clash of dates with the Personal Com puter World show in Lon don The organiser Eric Deeson says that about 40 of the major companies in the market are taking space The idea for Microscene Brum 82 on Saturday September 11 resulted from the successful ZX Microfairs in London Many people said how inconvenient it was having to go to London so we thought we would try for a regional show Deeson says He is hoping to at tract people from all over the Midlands and further north Meanwhile a general microcomputer fair is being held at Manchester on July 24 and 25 It is being held in conjunction with the University of Manchester Institute of Science and Technology at Sackville Street Man chester and is aimed at the education and small business markets Brain power wins ZX 81s TWENTY THREE regional winners in this year s Mensa Superbrain com petition have been award ZX 81s The awards were prompted by Clive Sinclair s involvement with the British Mensa Society of which he is chairman The competition is an annual event and is set to be a test of intelligence rather than memory as in Mastermind and Brain of Britain It is usually run in conjunction with provin cial newspapers on a regional basis with the regional winners pro ceeding to the final This
19. call sign along with the operator s name town the date and perhaps other details it is possible to recall immediately whether or not station has been contacted previously and to see the details of the contact The data can be sorted into call sign order to see how many coun tries have been contacted useful since many amateurs compete for certificates which are awarded for tacts with for example 100 countries Another use for the computer is to compile an index of technical articles in radio and electronics magazines Most radio amateurs like home computer enthusiasts ac cumulate magazines devoted to their hobby It is frustrating to search issue after issue looking for an article you remembered reading few months ago If a description of each article is stored in the com puter together with the name of the publication its issue date and the page number it is possible to have a program which will search the descriptions and produce a list of all the articles relating to a particular topic Typically more than 300 references can be stored on a 16K ZX 81 Another facet of amateur radio is contests On some weekends amateur operators from all over the world try to make as many contacts as possible in a given period usually 24 hours The scoring varies from contest to contest but usually is based on the number of contacts made and the number of country SINCLAIRUSER July1982 P
20. electronic projects thermometer burglar alarm voltmeter etc Byteing Deeper into your ZX81 by David Johnson Davies the bestseller which tells you how to get to grips with your 2X81 and with 39 programs to match ee o ee Order through READ OUT PUBLISHING COMPANY LTD 8 CAMP ROAD FARNBOROUGH HAMPSHIRE GU24 6EW 24 hour answi Name Address Make cheques payabie to Read Out Publishing Company Ltd enclose my cheque for g service Telephone 0252 510331 2 Please send me copy ies of All prices include postage C Getting Acquainted with your ZX81 8 95 Amazing Games forthe 1 5 95 49 Explosive Games or the 2X81 6 95 Learning to Use 281 due Learning to Use the ZX Spectrum 4 5 95 ue Aug Sep The Personal Computer Book 7 55 Mastering Machine Code on Your 2X81 Please debit my Access Signed I Number I I Gateway Guide tothe 2X81 074 The 2X81 Pocket Book 6 95 20 Simple Electronic Games for the ZXB1 746 _ Deeper into your XE 6 45 SINCLAIRUSER July 1982 READ OUT FOR SOFTWARE BOOKS 27 1 Into which range does your age fall Underi6C 16250 26350 36450 46550 56650 Over 650 2 Areyouinemployment yes no If yes g
21. 19 95 and the parallel port 18 95 Kempston Electronics is at 60 Adamson Court Hillgrounds Road Kemp ston Bedford MK42 8QZ Speech pack from DCP DCP has produced a speech pack which can be fitted directly to the back of a ZX 81 and which will not interfere with any planned expansion Using a maximum of two memory SINCLAIRUSER July1982 mapped ports at 49148 and 49149 the various ROMs containing the words can be POKEd via Basic to the loudspeaker included inside the unit The speech can be heard through the loudspeaker or if re quired can be amplified via the jack socket provid ed 8 ohms The amount of words it can say depends on the number of ROMs fitted inside the box A maximum of four can be fitted and the basic model is supplied with the first one available at 14 95 each including VAT and postage DCP Microdevel opments 2 Station Close Lingwood Norwich NR13 Thurnell motherboard THURNELL ELECTRONICS has now extended its range of equipment for the ZX 81 to include a mother board LED indicator board transistor driver board relay board to con trol up to 1 5A AC or 24V DC at are in cases but the original port is still available in kit form and without a case A motherboard can con nect up to four devices to the port at once The port is based on a Z 80A PIO Kempston s new keyboard Most of the words are measurements of one kind
22. CONVERTER BOARD CONVERSION dd CONSOLE HOUSES A a D pack Price now only 18 50 JOYSTICKS for the ZX81 only 9 60 each hannel analogue to ick control rement of of ZX AMAZE plus any one of th PROGRAMS AVAILABLE would like your ZX81 to look like this then send it to us and we will return it to you built into this cab including a 9 monitor connected directly to the vide of the 2 81 and a full mechanical key lock All for Alternately we can supply the cabinet only for 38 5 output Quite simply the best b Features seven bat angles fins RIVERSIDE HOUSE BRADLEY LANE NEWTON ABBOT DEVON TELEPHONE NEWTON 0626 68622 2X BOMBER Bomb and shoot doomed to cras jame each t play On the reverse of the cassette is 2X MICROWARE NEW SHOP IN LEICESTER FOR SINCLAIR COMPUTERS Keyboards Ram Packs 1 0 Parts Monitors Graphic Boards etc Games Serious Home Business Software Books amp Magazines MICROWARE 131 MELTON ROAD LEICESTER Tel 0533 681812 REFLEX find out how fast you really are now only 3 95 EEIEIEE The original and stil the best to load other prog Byte This is the fastest arcade typ
23. E7 Fun to Learn series Inventions 1 ICL Hardware required ZXB1 16K RAM Price 6 95 Programs Inventions before 1850 Inventions since 1850 Description Who invented television What was the dangerous Lucifer Cassette E8 Fun to Learn series Spelling 1 ICL Hardware required ZX81 16K RAM Price 6 95 Programs Series A1 A15 Series B1 B15 Description Listen to the word spoken on your tape recorder then spell it out on your 2 81 300 words in total suitable for 6 11 year olds Cassette Fun to Learn Business household Cassette B1 The Collector s Pack ICL Hardware required ZX81 16K RAM Price 9 95 Program Collector s Pack plus blank tape or side 2 for program data storage Description This comprehensive pro gram should allow collectors of stamps coins etc to hold up to 400 records of up to 6 different items on one cassette Keep your records up to date and sorted into order Cassette B2 The Club Record Controller ICL Hardware required ZX81 16K RAM Price 9 95 Program Club Record Controller plus blank tape on side 2 for program data storage Description Enables clubs to hold records of up to 100 members on one cassette Allows for names addresses phone numbers plus five lots of additional information eg type of membership To Sinclair Research FREEPOST Camberley Surrey GU15 Please send me the items I have indicat
24. LAM cw SINCLAIRUSER Eos pae sana tr ONLY SM or mor atas we July 1982 Philip Joy considers a game of chess written for the 1K ZX 81 and finds it is very restricted Simple chess limits moves O DISPEL some confusion about Noughts and Crosses have received a letter indicating that I made two state ments which contradict each other If you have ever played a computer version of the game it tends to be very easy to beat was the first comment That statement refers to a version of the game which contains no skill at all just the rules to play the game As you would agree an un interesting game with little skill demanded The second statement is Gives you a chance to win now and then unlike many Noughts and Crosses which are which are un beatable X SINCLAIRUSER July 1982 That one refers to what happens if you insert a large amount of skill it becomes unbeatable and boring If however you have the computer learn by your mistakes s the article was suggesting it will become more difficult as you play That will give players a chance to win providing that the player always plays to his normal standard I was also sent a 1K chess program in a neat package with a cassette inlay created on the ZX 81 printer with the instructions on it The author is D Horne Cowbridge East Sussex I have asked for some comments from two other people on the game and I thank Ian Benyon and
25. Leo Amatino for their help There are some restrictions on what the game can do because it had to be fitted into 1K Those restrictions are no castling no en passant and no pawn promote The comment on those restrictions was that it spoiled the game I shall stick out my neck and say what I have always said that the unexpanded ZX 81 cannot do anything construc tive except be used to control some thing I must also say that after I have seen the game my mind is not changed The game is satisfactory for 1K but is nothing like what can be achieved on the ZX 81 Amatino says he thinks it plays the same game and both he and Benyon say that it was a very short game Horne says it is the ultimate for the 1K ZX 81 I suppose that is true Itis neatly packaged and costs 5 Amatino said that it was not worth the money I would say that if you have a 1K ZX 81 you could have some enjoyment from this inexpen sive game A Leicester reader sends details on the Artic Computing ZXchess II He includes a game which I shall try 10 include in a future issue His comments are rather interesting as they support my point about the ond game He says The end game is less positive He says of the save facility of the game The most significant advantage of this particular program is the save facility Cumbrian reader has sent a game played against Sargon 2 5 and ZXchess ZXchess won He says that one bad mov
26. Out Graffiti Find the Mate Labyrinth Drop a Brick Continental Description Five games plus easy conversion between English and continental dress sizes Cassette G6 Super Programs 6 ICL Hardware required ZX81 16K RAM Price 4 95 Programs Galactic Invasion Journey into Danger Create Nine Hole Golf Solitaire Daylight Robbery Description Six games making full use of the ZXBI s moving graphics capability Cassette G7 Super Programs 7 ICL Hardware required 281 Price 495 Programs Racetrack Chase NIM Tower of Hanoi Docking the Spaceship Golf Description Six games including the fascinating Tower of Hanoi problem Cassette G8 Super Programs 8 ICL Hardware required 2 81 16K Price 4 95 Programs Star Trail plus blank tape on side 2 Description Can you as Captain Church of the UK spaceship Endeavour rid the galaxy of the Klingon menace Cassette G9 Blorhythms ICL Hardware required ZXB1 16K RAM Price 6 95 Programs What are Biorhythms Your Biohythms Description When will you be at your peak and trough physically emotionally and intellectually Cassette G10 Backgammon Psion Hardware required 2X81 16K RAM Price 5 95 Programs Backgammon Dice Description A great program using fast and efficient machine code with graphics board rolling dice and doub ling dice The dice program can be used for any
27. STARTREK 4 95 16K STARTREK Exciting space adventure game including Klingons starbases phasors 8 galaxy 4 levels of play long and short range scanners etc SUPER WIMPUS 4 95 16K SUPER WUMPUS Can you hunt and catch the mysterious wumpus in his underground labyrinth Intriguing underground adventure GRAPHIC GOLF 4 95 16K GRAPHIC GOLF Try out your golfing expertise on the computer s golf course 18 different graphically display holes Hazards include lakes trees wind rough etc GAMES PACK 1 4 95 16K GAMES PACK 1 Fantastic value for money nearly 50K of programs on one cassette Five games including Real Time Graphic Lunar Lander Starwars Hammurabi Minefield Mastermind ZX ZOMBIES 4 95 16K ZX ZOMBIES you escape the manrauding eating ZX ZOMBIES as the chase you for your FLESH Eight rounds of play highly addictive SILVERSOFT Dep SU7 35 Bader Park Bowerhill Melksham Wiltshire ZX ARCADE ACTION NEW 5 95 At last Pacman for your 2 81 the arcade features plus software for the QS character board SPACE INVADERS 4 95 Simply the best yet the closest thing to real Invaders on the ZXB1 Full arcade features including 1 or 2 player option and software to drive the QS character board ASTEROIDS 5 95 Authentic representation of the arcade game including L R thrust and fire controls levels of play and alien spacesh
28. Sinclair Research is sponsoring the event with 5 000 and it is expected that 2 000 competitors will be taking part including a number of top class runners The race will be held on Sunday July 18 and will SINCLAIRUSER July 1982 follow course through the city s historic streets The company which is based in Cambridge sees the sponsorship of the race as part of supporting the cultural life in the city It will also be sponsoring a concert in King s College Cambridge as part of the festival John Rowland market develop ment manager of W Smith will be selling more than 100 lines of software Rowland says that in the next few years W H Smith would probably like to sell about three machines with full range of hardware add ons and software After that he thinks the market will probably go the same way as the record market with some retailers concentrating on hardware and others on software Of the hardware market he says that Smith s entry will depend on manufacturers agree ing to standard interface Without that it would not be possible to generate sufficient sales to make it worthwhile The retailer is looking for high volume sales which is why it chose to enter the market with the ZX 81 Rowland added that Smiths is also looking at the possibility of becoming a software publisher The company already receives many suggestions each week ZX fairs spread to North
29. a particularly innovative product model It would be pleasant to think it would be a British company which takes the plunge THERE IS possibly something to said for the ponderous decision structures of many of Britain s major companies With the limitation of personal initiative and the promotion of company spirit the wish to leave and start a new business is severely curtailed Compare that to Clive Sinclair s companies past and present where initiative and freedom of thought have been encouraged It is one of the benefits of being a small company that it is possible and it has been used by Sinclair Research especially to put new ideas into practice quickly The freedom however is not total In the end it is Clive Sinclair who takes the important decisions Having tasted some easing of constraints it can be very frustrating when there is still some limitation to action Itwas that frustration which led to the departure of Richard Altwasser to join a growing band of former Sinclair colleagues from whom he now faces some form of competition The people behind Acorn Computers and the Grundy Newbrain which finally was launched last month all worked with Sinclair at some stage Altwasser and his partner Steven Vickers are keeping quiet about their plans but it is unlikely they will be straying far from the microcomputer field they know so well Whether their new company will be big enough to consider launching a
30. a quick apprecia tion of how to move the figure Zuckman is available from Software 9 Tweed Close Swindon Wiltshire Parlez vous le Basic A CASSETTE to help children with GCE O level French examinations has been produced by Rose Cassettes which specialises in educational software for the ZX 81 For use with the 18K RAM pack it covers grammar and vocabulary On the first side there are three sections dealing with verbs pronouns and ad jectives with lessons followed by tests The second side deals with vocabulary with 345 nouns more than 190 verbs and about 290 com mon expressit The cassette is available from Rose Cassettes 148 Widney Lane Solihull West Midlands at a cost of 4 50 including postage Fighting the ce aliens FOR THE intrepid fighter against all things alien Astro Invaders is the lead game in a pack available from John Prince Software costing 3 65 According to the com pany there is no superior version of the game on the market at such a com petitive price In machine code it runs automatically on loading and involves 54 manoeuvring aliens which are knocked out by photon firing torpedoes As the game proceeds the attack rate increases The other games in the pack are Grand Prix Penalty Golf and Swat John Prince Software is at 29 Brook Avenue Levenshulme Man chester 45 Micro Gen ouau ZX81 THE ULTIMATE ZX81 A D
31. characters in and then to POKE into locations 16514 to 16537 the values given in the table following the program listing The routine returns a value of O if no signal is present at the input port or positive number one is present There is a Sinclair Amateur Radio Users Group in the U K Anyone in terested should contact Paul Newman G4INP 3 Red House Lane Leiston Suffolk IP16 4JZ enclosing a stamped addressed envelope for details 23 NEED MORE MEMORY FOR YOUR 2 81 46k Bank Account cassette by Futuresoft 3 Trade in on our 16k unit 64K 47 95 for a 64k unit if returned within 6 months we st Pretorius Systems have comm ioned a leading electronics company to design for us a low cost VERY high quality memory module specifically for the ZXHB1 It can be used in any expansion system and such The 16k imply Plugs into the back of yaur ZX81 and fully compatible with the ZXB1 printer module will give you 16 times more memory and is finished in ABS plastic Their is also 64k version which will provide you with a pure 64k of program POWER This amazing achievement is packed into exactly the same casing the 16k module and looks identical Note these units are BRITISH made and should not be confused with low quality importe that overheat and have sloppy connectors Nothing more to pay Prices include VAT FREE postage ove 44 days money bac
32. had to find the socket in which to plug the socket in which to plug the plug Several hours later I emerged hot and dusty from under the bed and there was the magic K Fingers at the ready I turned once more to the excellent manual which 1 cannot praise enough for its clarity and wealth of incidental detail 1 had no difficulty with adding 2 2 cursors the history of computer languages and how to erase mistakes but the chapter on using the computer as a calculator caused a twinge of anxiety I don t even use a calculator as a calculator I know what a square root is and even pi although I can not remember when I last used it but integers and exponential functions They must have done those while I was away from school with chicken pox Anyway having managed without them for so long I thought I might continue to do so and skipped to the next section That looked more promising being all about the price of eggs Those I do use and although I can usually work out their price give or take a few pence in my head it amused me to let the computer do it It could even the manual said tell shall soon be able to dispense with her services Things took a downturn however with the price of butter and yeast Having missed a vital piece of information about semi colons buried treacherously as I later discovered in that frightening mass of higher mathematics I suddenly lost control A stern S for Stup
33. me as soon as possible the following l enclose Cheque P O for the total NAME ADDRESS POSTCODE die mereri eddie res KAYDE Electronic Systems ZX80 1 ZX KEYBOARD WITH REPEAT KEY Fully cased keybo Uncased keyboard Keyboard Case KAYDE 16K Tho 16K RAMPACK simply KAYDE FLEXIBLE RIBBON CONNECTOR 1 Stops movement of RAM PACK and other accessories 1 2 2 Not needed with a Ine Vay KAYDE 4K GRAPHICS BOARD DE T set of space invaders Puckman Bullts Bombs NO EXTRA POWER NEEDED KAYDE 16K GRAPHICS BOARD SOFTWARE Post to Dept SU Kayde Electronic Systems Ltd The Conge Great Yarmouth Norfolk NR30 1P Tel 0493 57867 Dept St Don t Forget you can always order on the telephone with your credit card products include VAT are fully ease 1 50 PI P for hardware and 50 forall software built and tested and come with a Presse make cheques payable to Kayde Electronic Systems Ltd COMPLETE MONEY BACK GUARANTEE
34. my ZX 81 and it had a response time of less than half a second Writing that program however had taken eight complete days of my summer holiday Broadly speaking there are three types of program available to aid the budding machine code adventurer The most complex and probably most useful programs are the as semblers which convert mnemonics into machine code then there are disassemblers which do the reverse and finally monitor programs which allow close ex amination of a machine code SINCLAIRUSER July 1982 program as it runs plus other functions When Zilog produced the 7 80 microprocessor each of its hundreds of instructions was given a mnemonic so that users could remember what particular instruction would do For example LD A H means load the Accumu lator with the contents of the H register and represents 124 in machine code The mnemonic is entirely arbitrary and could just as well have been LOAD A FROM H We could produce a machine code program by POKEing instruc tions byte by byte into RAM and plenty of machine code loader programs do just that The method aids program for Basic keywords LD CALL and then places the corre ponding instruction in the RAM The ability to use labels makes an assembler very powerful as it allows the programmer to refer to instruction lines subroutines and even data by means of symbols rather than having to determine the addresses each ti
35. new computer is open to conjecture Leaving that aside for the moment there is still a large market in software and hardware peripherals where they could compete with their former employer Simplicity is best learning pattern Dave Sayers relates how the ZX 81 has helped learning in his school HE POWER of a micro as a learning tool is often quoted in papers and magazines yet most of the published programs are games and adventures and good they are too Nonetheless it is a pity that more educational games are not published the little ZX 81 with even a basic 1 memory can be used to teach many of the fundamentals of mathematics or with more memory English The example programs included in this article therefore are all written within 1K The reason is simple To be good a teaching game need not be complicated Preferably it should teach only one thing though that is not to say that mixtures of approaches are not desirable It should also if possible have a graphics display to help keep the attention of the child Another good reason for keeping games simple is that many ZX owners or owners of other machines are young people used to help to teach children who can count who have difficulty in associating those numbers with the written number for instance seven As you can see I am starting at the very first basis of counting My daughter has started learning to write or record number
36. previously d in the correct date order of the operation Utilises a M C keyboard sc Search for a or items by cheque number d amount display and printout if required with Continuous display of 5 extract continually Updated an be displayed printed added to Send 9 95 Gibbons ALB land Send large S A E for deta There are only two suppliers of supported ZX81 software t one of them Be clo name and a Coming soon Bank Reconciliation progra fhe main pro The only expandable system for the The Personal Banking System i Londe to J P the Buffer Bookshop 51 Two of leading figures in development of the Spectrum Richard Altwasser and Steven Vickers have cut their links with Sinclair and set up their own company Secret plans laid by new company WO OF the leading figures in the development of the ZX Spectrum have cut their links with Sinclair Research to set up their own company Richard Altwasser who designed the hardware and Steven Vickers who wrote the programs for the ROM working memory have formed Rainbow Computing Co Apart from publishing a book of programs for the Spectrum the company plans are a closely guarded secret It is necessary for us to be very cagey and apart from the one thing which we have announced we would like to leave anything we are doing secret until it is ready for launching says Altwasser H
37. ready to go into production which meant that not only had all the develop ment work to be done at Sinclair Research but also all the suppliers had to be chosen and the production lines at Timex had to be tooled up That had to be done in conditions of great secrecy and very little infor SINCLAIRUSER July 1982 Steve d Richard Altwasse mation leaked out about the machine although Altwasser says he was surprised by how much was known about it before the launch In the end with many nights of working late the deadline was met and the Spectrum launched on time Other benefits of working for Sinclair were that there was no shortage of money for research and as it was a small company it was easy to obtain quick decisions on new ideas and new ways of doing things When I went for interview I asked about money being available if a piece of equipment was needed and was told that a request was never refused but that they might SINCLAIRUSER July 1982 ht in front of lege Cambridge advise about something which would be better say Altwasser For the future Vickers and Altwasser say they are concerned to prevent a Japanese invasion of the British market Their plans for doing that however are to remain secret Asked if their name denoted any link with the Spectrum Altwasser replies that the only connection was that it has been one of the sugges tions for the new machine which they had liked so ha
38. satellite is visible from a location and in which direc tion to point the aerials SINCLAIRUSER July 1982 One problem which radio amateurs soon encounter when they put a computer in the shack is in terference The ZX 81 radiates good deal of radio noise which is picked up by the receiver and can easily obliterate weak signals Usually it is necessary to screen the case carefully using aluminium foil and to filter the lead from the power supply The RAM pack must be screened as well The reverse of that situation can also occur when RF from the transmitter interferes with the operation of the computer This is not usually a problem with the ZX 81 however although the tele vision used for the display can be af fected sometimes Once those problems have been overcome the computer can be used on the air to send and receive program the computer to scan the band for stations using Morse code and reply to them automatically It is possible to generate Morse code without using additional hard ware using the cassette output socket That output can be fed into an amplifier or recorded on tape for Morse practice It is also possible to feed code into the cassette input socket decode it and display the text on the screen The main diffi culty is that in SLOW mode the ZX 81 spends about 15 out of every 20 milliseconds displaying a picture on the TV and that interferes with the generation or reception of
39. the code Thus programs for Morse or RTTY usually are written to run in FAST mode A Morse decoder has been developed which will display on the screen code which is fed into the cassette input socket at a suitable level Since it runs in FAST mode the text can be read only once the program stops when the screen is full or once the BREAK key is ed Noise and interference will upset the decoding and the signal should go ideally through a narrow band filter so that only the wanted signal is fed into the ZX 81 The program uses a short USR routine to read the cassette input port The routine is 24 bytes long The computer can be used on the air to send and receive Morse code and radio teletype signals Morse code and radio teletype signals and even to control the sta tion Many of the new amateur radio transceivers use a microprocessor tocontrol the various functions such as frequency and mode and the various control lines are brought out to a socket at the back Using a suitable interface it would be possible to program the 2 81 to scan selected frequencies perhaps to record whether or not a signal is present to build a picture of amateur band activity at various times of the day or to monitor the strength of particular distant stations It would even be possible to and is stored in the first REM state ment of the program The easiest way to enter the routine is to type in REM with 24
40. the operating functions of the ROM except the floating point calculator Part B lists all locations from to IDFFH and covers all the routines involved in the evaluation of an expression and a detailed explanation of the floating point calculator Co authored by Dr Frank O Hara Part pages 7 80 including post pack and VAT Part B 84 pages 880 including post pack and Other titles available Not only 30 programs for the Sinclair 2 81 1K Complete Sinclair ZX81 Basic Course Not only over 30 programs trom arcade games to The Complete Basic Course is 240 page in depth the final challenging Draughts playing program comprehensive text for complete beginners and which fit into the unexpanded Ik Sinclar 2 81 but experienced programmers Over programs and notes on how these programs were written and examples ilustrate the use and possiblities of the special tips Great value Sinclair ZX8 This 6 an invaluable reference guide for RO pages 1775 28 owners 256 poges 1830 Special Discount for ordering more than 1 titie If you order more than one at time you get a discount of per additional tite If you order 2 books deduct from the totat order 3 books and deduct 160 order 4 books and Orders Metboune House Pubsshers 13 Rood Greenwich London SEO C memndence Yo Gepe Staton food Chaddngion Legion Burro BEDS LU None R
41. the printer suitable for printing ready gummed labels asks John Modha of Greenford Midlesex Unfortunately the answer is no 56 Peripheral difficulties Andrew Hewson answers more of your problems including some worries about the Spectrum and possible add ons The ZX printer is capable only of printing on the special aluminium coated paper supplied with it I suggest you look at advertisements as one or two firms supply a printer interface which allows the ZX 81 to drive a conventional printer Alan Pitcher of Jersey says Ihave just ordered a Spectrum Can you suggest a cassette unit to use with it Sinclair has improved the cassette facilities markedly in the design of the Spectrum and so it is hoped that we will all find it much easier to use than the ZX 80 and ZX 81 in that respect Instead of recommending a cassette player which might not be available in your area 1 suggest that you choose a shop which sells a variety of players and take your computer your TV and a typical cassette and make sure you can LOAD and SAVE before you buy I have done that and found that shopkeepers are happy to help provided you ask permission and explain the problem My advice to Peter Stokes of Great Missenden is similar He writes I would like to replace the TV I use with my ZX 81 by a small monitor to obtain better video resolution Can you advise me I would not bother to use video m
42. to use the ZX their fathers or brothers own one and they can crib my programs enjoyed it a great deal The colleague who was interested in SINCLAIRUSER July1982 what the computer could was Surprised by the way in which some of the less motivated children were captivated by the game She was particularly impressed with the way in which one boy who was finding addition a trial began to store the numbers in his head then staring into space for a minute or so when he had about written sums would often be at the teacher s desk complaining that he could not understand Replacing it was the desire to beat the computer to have his answer before it flashed on the screen BRIDGES is a game in which the children attempt to build bridge by rather than numbers figure five When the game is run blocks in two rows appear on the screen If they are added correctly a span is added to the bridge If they are not added correctly there is no penalty the problem resumes again and again until it is solved correctly That is important as there is no worry that the child will feel he or she has failed on the first few attempts if the bridge is not nearing completion Those with 16 or more K of memory might like to improve this program For instance the bridge may fill the whole screen and every time there is an incorrect answer a man might walk along the bridge a
43. which are different from any thing else on the market Shelob s Lair is 13K Basic and machine code game which gives a 3D im age of your location and shows all the exits in perspective There are plenty of monsters and treasures represented in words rather than graphics scat tered around the 180 rooms The room displays are generated using code and are impressively fast The layout and the contents of the rooms change only if you reach a different level in which case a set of tougher monsters and more valuable treasures is generated The other program is Mines and Monsters which allows up to four players to play at the same time Itis a 13K Basic game in which all the locations treasures and monsters are generated randomly at each turn Itisnot very exciting but is entertaining enough and useful if only to avoid family arguments about who can use the ZX 81 Both programs cost 3 50 Shelob s Lair being packaged with an nomy simulation game and Mines and Monsters hav ing a multi player stock market game Algor is at Dovercourt St James Road Northampton Zuckman for the ZX 81 WHAT IS said to be the first ZX 81 version of the popular arcade game has been produc ed by DJL Software Called Zuckman it runs on the ZX B1 with the 16K RAM pack It is very user friendly giving complete instruc tions for playing Written in machine code it is a fast and interesting game and requires
44. whole TV screen without the need for further instructions So now you can print out your results for a permanent record The 2 Printer plugs into the rear of your ZX81 and you can connect a RAM pack as well Games Cassette G1 Super Programs 1 ICL Hardware required 2 81 Price 4 95 Programs Invasion trom Jupiter Skittles Magic Square Doodle Kim Liquid Capacity Description Five games programs plus easy conversion between pints gallons and litres Cassette G2 Super Programs 2 ICL Hardware required 2 81 Price 4 95 Programs Rings around Saturn Secret Code Mindboggling Silhouette Memory Test Metric conversion Description Five games plus easy conversion between inches feet yards and centimetres metres Cassette G3 Super Programs 3 ICL Hardware required ZXBI Price 4 95 Programs Train Race Challenge Secret Message Mind that Meteor Character Doodle Currency Conversion Description Fives games plus currency conversion at will for example dollars to pounds Cassette G4 Super Programs 4 ICL Hardware required ZXBI Price 4 95 Programs Down Under Submarines Doodling with Graphics The Invisible Invader Reaction Petrol Description Five games plus easy conversion between miles per gallon and European fuel consumption figures Cassette G5 Super Programs 5 ICL Hardware required 2 81 16K RAM Price 4 95 Programs Martian Knock
45. year for the first time ex tra sections were organis ed through the indepen dent local radio network which provided five regional winners 21 4 Radio Sinclair There seems to be no limit to the uses which can be found for the ZX 81 Here Julian Moss reports how it has been of help in amateur radio MATEUR RADIO is a hobby as radio itself Ever since arconi sent the first transmission across the Atlantic radio amateurs have been ex perimenting with new modes of com munication and in the process mak ing friends across the world Many of today s radio amateurs use commercially made equipment but there is still a good deal of ex perimenting in aerial design for ex ample and at very high frequencies Like any technical hobby there are many uses for a computer and the ZX 81 has found its way into many radio shacks Its uses fall primarily into three areas information storage and retrieval mathematical and scientific programs and real time on the air applications Programs in the first category are fairly straightforward One ex ample is an index of radio stations contacted or heard Every radio amateur has his own call sign in which the first two or three characters denote the country for example the G4 in the call sign G4ILO indicates England Since typical ham may make thousands of contacts in a year it is impossible to remember every one By storing on the computer each
46. 190 _D A B THEN GOTO PRINT THERE WERE C SNA 200 GOTO 60 290 PRINT YOU BUILT A BRIDGE SINCLAIRUSER July 1982 7 Fully programmable high resolution 192 248 pixels anywhere in the RAM trade in offer Instant inverse video purchase of our 64K model it Video pages can be Access to video page superimposed by similar to plot and you return your 16K pack within 3 software switching commands in BASIC months of receipt you supply evidence of purchase your 16K model is rec undamaged and unopened styled to fit onto the back of the ZX81 allowing more add ons Memopak ed by us RAM Sinclair printer etc to be connected without a further power supply contains a 2K EPROM monitor holding a full range of graphics subroutines which can be called by the BASIC USR function or by machine code Memopak 16K Memory Extension Iis a fact that the ZXB1 has revolutionised home computing and coupled with the new 16K it gives you a massive 16K of Directly Addressable RAM which is neither switched nor paged With the addition of the Memopak 16K your 2 81 s enlarged memory capacity will enable it to execute longer and more sophisticated programs and to hold an extended database The 16K and 64K Memopaks come in attractive custom designed and engineered cases which fit snugly on to the back of the 2 81 giving firm wobble free connections Memopak 64K M
47. 6K PROGRAM SAVE GAME ROUTINE SINGLE KEY ENTRY Volcanic Dungeon i terrific value and would recommend it to anyone Mrs Thomas Cornwall HANGMAN Delux version of the classic game Play against an ponent ort computers 400 word vocabulary Good graphies C3 ALIEN INTRUDER HIEROGLYPHICS 5 00 ALIEN INTRUDER You awaken to find you are the only survivor on Explorer Class 3 Starship Can you escape before you aiso fall victim to the Allen monstrosity that devoured the crew There are many ways to fend this adventure but only one way to survivel FULL 16K PROGRAM INTERACTIVE GRAPHICS SAVE GAME ROUTINE B HEIROGLYPHICS Decode the ancient 39 symbol alphabet in time to Save the famous explorer Wullie from a sandy grave FULL 16K PROGRAM ANIMATED GRAPHIC DISPLAY RANDOM CODE C4 WUMPUS ADVENT RE MOVIE MOGUL 5 00 WUMPUS ADVENTURE FOR 1 TO 4 PLAYERS Seek the famous in the most dangerous Wumpus hunt ever the usual features are there SUPERBATS PITS TREMORS SWAMPS ARROWS PLUS Exciting new features EVIL GOBLINS that wil try to sacrifice you to the Wumpus a GIANT SERPENTS WUMPUS MUCK MAGIC SPRINGS FULL 16K PROGRAM RANDOM PRESET CAVE PATTERNS YOU CONTROL THE LEVEL OF DIFFICULTY FUN FOR YOU AND YOUR FRIENDS 8 MOVIE MOGUL Guide your fim through the often hilarious traumas ot production Use your budg
48. DE ices include VAT and U K P amp P Add appropriate Postage on Foreign Orders Cheques P 0 s to J K GREYE SOFTWARE Dept SU 16 Park St Bath Avon 2TE CREDIT CARD SALES Phone 01 839 4465 9 a m 7 p m FOR INSTANT DESPATCH vou prefer to se before buving BUFFER MICROSHOP 3744 Svestham High Rd London SW16 GEORGES mrs Si Avon MICROSTYLE 25 Lansdown Ra Bath Avon MICROWARE 31 Maior ood SCREEN SCENE 144 St Georges Cheltenham Gos SMITH Computer Branches JEDXTMA 5 School Lare Kinson Boumemoum Dore TRADE amp EXPORT ENQUIRIES WELCOME SINCLAIRUSER July 1982 ZX Spectrum 20 Programs 6 95 The ZX Spectrum has brought advanced computing power into your home The Cambridge Colour Collection a book of 20 programs is all you need to make it come alive No experience required Simply enter the programs from the book or load them from tape 2 95 extra and run Amazing effects All programs are fully animated using hi res graphics colour and sound wherever possible Entirely original None of these programs has ever been published before Proven Quality The author already has 30 000 satisfied purchasers of his book of ZX81 programs Hours of entertainment Lunar Landing Control angle of descent and jet thrust to steer the lunar module to a safe landing on the moon s surface Maze Find your way out from the centre of a random ma
49. LEARNING IS FUN WITH THE 2 81 We look inside Spectrum ZX81 B B C MICRO VIC Usa A MAZE ADVENTURE GAME FOR 500 DICTATOR 6 50 DAMSEL amp THE Bi STELLATION RAM PACKS ee VICMEN ESNS 065 ANOTHER VIC IN THE WALL 7 00 is a brand new game for 16K 2 81 67 unlike any other game you ve seen the ZXBl This is ASTEROIDS 70 without doubt the best game available for this computer and if you don t believe us ask somebody who has J seen it ar go down to your local computer shop and ask for demonstration MAZOGS is moze adventure game with very fast Bac CHESS ER moving animated graphics A large proportion of he MULTIFILE program is written in machine code to achieve the most B B C BACKGAMMON amazing graphics you have ever seen on the 2 81 BBC GOLF_ et You will be confronted by a large and complex Maze which contains somewhere within it a glittering and fabulous Treasure You not only have the problem of finding the treasure and bringing it out of the maze you must also face the guardians of the maze in the form of a force of fearful Mazogs Even if you survive their attacks you could still starve to death if you get hopelessly lost Fortunately there are various ways in 4 00 which you can get help on this dangerous mission There are three levels of difficulty and the game comes E
50. OU AE in 3O ie T REX wl towards you in fui perpectvel you ve never 30 MONSTER MAZE is ihe best game have seen forthe TAI COMPUTER VIDED GAMES had to choose just one programme to moress withthe capabilites of the then 7 Grey s 30 MONS TER MAZE wound be thee 2x COMPUTING GAMESTAPE Stor 10K oniy 4 96 ID DEFENDER The Uer Space Game Spem fast Macnre Coge 30 version ol the Arcade favourite You have your home planet hom the maranin Alen Thies bi your varwscreen shows you the vae Out Of your cockpa maraow The bachirop moves whan Vol tur or y up down 18 fight svectons jst aa you rere ready ying ni But than YOU ARE The Enemy Saucers i scaly zoom ard vou in 10 and shoot you yoy You dag Score Sd We Prony Forward Radar and CP shows your home planet back of Stars Meteors Beane Sat vor Proton tere up Saucen a o cove tw S fargo SMASH et the of tha other sors houses wart copy a game not GAMESTAPE for 1K tim BREAKOUT Super Fost Ful Screen Game Your 9 te favourite oth en added tat Set hom moch Money ou can win and waten the pounds conver Yo Dollars AL Tr Machine Code Fast Acton with 3 Speeds 2 Bat Sizes nd eve angles of rebound The best BREAKOUT around GAMES MARKED INCL MACHINE CO
51. PUTING S ZX CHESS 11 45 00 The Mat obese px io with levela o play POSTAL AND MONEY ORDERS TO ALL PRODUCTS FULLY GUARANTED QUICKSILVA 98 UPPER BROWNHILL RD MAYBUSH SOTON HANTS ENGLAND Please state Type of machine Which ROM Memory size when ordering wih Tempting gap in market F ANYONE questioned the size of the possible market for home computers they should take note of the experience of W H Smith The company sells more magazines on computers than it does women s magazines There are three computer publications which sell more copies than the most popular women s magazine This explains why Smiths is expanding that side of its retailing steadily As the company puts it most of its sales are in maturing markets so the need to find new and dynamic lines is essential for its future The growth potential is phenomenal It is estimated that despite sales of almost 500 000 ZX 81s Sinclair Research has tapped only about two percent of the estimated home computer market Despite allowing for the fact that it is difficult to assess a market which did not exist two years ago there is still an enormous hole in the market Smith s reaction in the medium term is to try to cover the whole market for both hardware and software In the long term it is thinking of specialising on one sector probably software That ensures that the route future development will follow is much the same as that for the mu
52. QUE OR P O TO PSS 112 OLIVER STREET COVENTRY CV6 SFE ZXS81 Software Business Software 16k amp 32k FOR SMALL BUSINESSES AND THE SELF EMPLOYED BUSINESS BANK ACCOUNT This program enables you to make debits under 11 sub headings Statements include totals of all sub headings PURCHASE LEDGER Keeps a comple yd of your receipts under 11 sub headings The program will calculate amp deduct VAT SALES LEDGER For all your invoices The program will calculate VAT and list all outstanding invoices the programs will except entries up to 99999 99 amp will enable you to produce your accounts at the touch of a button Programs can also be used if you are not registered for 16K programs accept up to 225 entries 8 75 32K programs accept up to 675 entries 10 75 Special Packs including all 3 programs 16K 25 32K 30 VAT amp PROFIT CALCULATOR 3 50 Educational Software 16 k SPELLBOUND Spelibound game for 1 4 players Program will accept up to 600 words Can also be used to test spelling 4 75 TRANSFORM LTD For details send S A E to 41 Keats Ho Porchester Mead Beckenham Kent 01 658 1661 Callers welcome ZX HARDWARE Professional 40 key keyboard All legends and gr No soldering to 2 81 just plug in Proper typewriter keys RAM Printer compatible Kit 19 95 Built 24 95 Case 10 20 Repeat key add on ics in 2 colours
53. R THE MORE DISCERNING ENTHUSIAST rm FUTURESOFT 8 PENSHURST ESTATE PRINCE OF WALES ROAD LONDON 5 Itis hard enough to look an amorphous hydrosilicon blob from Psi never mind swing a deal with one But when they ask to pick your brains do you really know what they have in 7 Trader is a new concept in 2 81 games It is a graphic adventure so big that it fills your 16K Ram three times You are an intergalactic trader and the life is tough the bargaining hard You can make a fortune or end up spaced out in a Deltan hellhole Trader 48K of adventure that will run in your 16K Ram It costs 10 50 inclusive Send SAE for more details of Pixel games PIXEL Pixel Productions 39 Ripley Gdns London SW14 50 E00 B A EE MANAGER E Zx VIDEO GENIE DIVISIONS AS SEASONS YOU LIKE 4 D FLEGATION 1 PROMOTION amp FULL E TRAN Ri 1 UE TABLES SEER X INJURIES X7LEVEIS OF PLAYE SAVE GAME FACILITY das X MANAGERIAL PICK YOUR TEAM FOR FACH MATCH w 1 This i NOT mere simulation This iv an exciting and highly enj in which vou play the part uf a ist them here but included are form ia NORMALLY win xiant billings wage billy to pay and you cun sacked is a game requiring a reat deal of kil and literals MILTON RAM TEVELTI
54. Tel Camberley 0276 66104 amp 21282 Code price Total 2 Engin Geography Y Ea History Y ar V CAL ee wae ezes RETURN to the knotty problem I transferring data between programs but first I have some questions concerning peripherals Peter Mann of Bedfordshire writes I have been told that if I use my existing hi fi cassette deck on the new Spectrum the computer would blow up Why should that be so 1 would much rather use my deck than have to try a portable tape recorder The Spectrum is a low voltage device designed to detect and decode the kind of poorly reproduced low voltage signal levels obtainable from the earpiece of a cheap portable tape recorder In contrast a hi fi system is designed to deliver an accurately reproduced signal with sufficient power to fill a room with sound Large voltage fluctuations are normal from a hi fi system even at low volume levels and so connecting a Spectrum to a hi fi system clearly risks over loading the computer To make the most of a Spectrum you need it on a large table or desk with TV cassette player books magazines pencil and paper to hand I can understand that you do not wish to spend money necessarily on a portable cassette player but I am sure you would find it much more convenient to use Recently I have bought a ZX 81 for business use and am thinking of buying a ZX printer Is
55. ZX81 users and are fed up with the dead touch sensitive key pad then consider the advan tages of the new KEMPSTON KLIK KEYBOARD This is genuine push button keyboard which has been designed as an exact replacement being no larger than the existing key pad but offering all the advantages of a full size keyboard Consider these facts Fitson to the 2X81 No soldering needed on the assembled version just plug in No trailing wires No special case required Positive feedback from keys Full two colour legends supplied Full back up service offered including fitting This is a genuine 40 key push button keyboard which fits into the recess formed after peeling off the existing touch sensitive keypad The kit comes with a precision drilled P C B finished in matt black 40 keys 2 colour legends connecting tails adhesive pads and a full set of instructions Also available from our range of products is a Parallel User 1 0 post 16 50 built amp tested Gives 161 0 lines to drive light relays motors etc Many already sold to education Keyboard bleeper 8 95 built repeat key kit 2 95 MOVING AHEAD WITH ZX SOFTWARE ZX CHESS amp ADVENTURES zx FORTH of FORTH for the 2 10 26 Simplcity of BASIC with 16K RAM PACKS Guorantascnauch RAM PACK Tha bast yous Loy We didn t think n was possible but the game plays
56. ader and a limited company They are written for use mainly by accountants but they can also be useful to the small trader with a little knowledge of accounting Figures can be entered into the accounts in the usual forms including cash payments and re ceipts and bank payments and receipts Using a system of coding the ac counts are then built up from those printing out all the records of interest to the company The programs are avail able from Hestacrest PO Box 19 Leighton Buzzard Bedfordshire LU7 ODG costing 17 50 each or 25 for the two Improved Othello MINE of Information has produced what it claims to be an improved version of its game Othello The im provements include more features for a lower total price of 6 90 better loading and easier use All input is said to be crashproof and loading problems have been over come by a hardware modification to generate a strong clean original SINCLAIRUSER July1982 signal and tape duplica tion using signal enhancement process The new features in clude the ability to replay moves at any stage both forward and backward The new program known as version 3 5 was shown at the ZX Microfair at the beginning of April and lost only one contest out of 30 when playing at half power Othello is available from Mine of Information 1 Francis Avenue St Albans Hertfordshire Adventures from Algor ALGOR has produced two adventure games
57. at is 0 25mHz faster than the 2 81 The Z 80A has also been SINCLAIRUSER July1982 freed of the job of putting out the screen by the ULA and so no longer requires the commands FAST or SLOW as it works at top speed all the time except when BEEP or PAUSE is use PAUSE and BEEP both cause the Z 80A to stop for a time determined by the programmer and so it will do nothing else while those commands are being done BEEP commands should be kept short in a program for that reason 0 01 seconds is a good speed to PRINT AT and BEEP at the same time As for programming the Spectrum it can be considered as an extension of the ZX 81 Basic The PAPER INK BRIGHT and FLASH commands for each character square are stored in a memory map above the dots for each character They are all stored in one byte per character and can be read by the Basic word ATTR and altered either by Basic commands POKEs The dot screen is a different matter however and cannot be SINCLAIRUSER July 1982 altered so easily as the dots are stored in peculiar order so you hav to use the graphics which can define all the dots on the 22 line by 32 character screen available to the user or the SCREEN command There can be only two colours for each character square one for the foreground INK and one for the background PAPER but they can ny one of eight colours They can also be inverted at a rate of one per seco
58. at those times mostly I like to work in the evenings which can be the worst time for the pro blem Iknow that you can ob tain a filler unit which goes between the wall socket and the computer plug which will suppress the spikes but I do not know which type would be best for my ZX 81 Could you advise me as to which method of solving the problem you would suggest and where the goods can be obtained Paul Coker London SE19 readers help We are sending it to our Helpline correspondent Andrew Hewson to see if he knows the answer Apple threat 1 AM very grateful for the Aprilissue of Sinclair User but it does not tell me how to make my printer work The books which are sold do not tell you either It would be much better if you told people how a ZX 81 works otherwise I shall have to sell mine and buy an Apple I write and write again to Sinclair without even an acknowledgment Maurice Nadin Surrey eWe hope later issues have been more help and that you have not been compelled to take the drastic step of buying an Apple Changing to machine code CONGRATULATIONS on an excellent magazine It is just what ZX users wanted I am not a pro grammer and prior to buy ing my ZX I did not have a clue Through practice I am rapidly picking up the techniques and find the hobby very interesting I find having bought some programs written in machine code that they are eminently supe
59. course be over written and so the final step is to copy it back from above RAMTOP A machine code routine is needed for that step because space must be created in the program area in which to store the program using a routine in ROM The routine is 20 bytes long and I suggest you store it at addresses 32748 to 32767 by entering and RUNning the following routine 10 for I 32748 to 32767 20 INPUT 30 POKE 1 40 PRINT I PEEK 1 50 NEXT I Enter the following numbers one by one from the keyboard 42 12 64 229 43 1 0 0 197 205 158 9 193 209 42 4 64 237 176 201 You might like to determine how the routine works by translating the decimal numbers into Z 80 assembler using Appendix A of the ZX 81 Basic Programming manual Before running the machine code routine POKE the program length J into it by entering POKE 32754 256 INT J 256 POKE 32755 INT 256 Then delete the Basic routine put the ZX 81 into FAST mode and call the machine code routine by entering IF USE 32748 0 THEN STOP 9 Hewson Consultants 1982 Please address problems and queries to Andrew Hewson Helpline Graham Close Blewbury Oxfordshire 57 PERSONAL SOFTWARE SERVICES MACHINE CODE GAMES ACTION AVAILABLE BREAKOUT PLUS SUPERBREAKO 0 3 THE ABOVE PROGRAMS ARE ONLY A SMALL SELECTION FROM OUR ALL OF WHICH 15 AVAILABLE SEND SAE FOR FULL DETAILS WIDE RANGE OF 2 81 SOFTWARE CHE
60. d decided to use it One of their major concerns is that they should be able tokeep pace with the latest developments in their field There will always be the fear that something you have designed will be out of date as soon as you have finished it he says They also think that the present generation of computer tech nologists will find increased pressure from today s school children Altwasser says that teenagers are now able to grasp ideas with which he had difficulty less than three years ago He adds that at the Earls Court Computer Fair he saw some children with leaflets about the Spectrum As a joke he decided to ask them about it and was told enthusiastically about its capabilities A whole new range of software for the Sinclair ZX81 Personal Computer is nowavailable direct from Sinclair Produced by ICL and Psion these really excellent cassettes cover games education and business household management Some of the more elaborate grams can only be run on a 2 81 augmented by the ZX 16K RAM pack The description of each cassette makes it clear what hardware is required The RAM pack provides 16 times more memory in one complete module and simply plugs into the rear of a 2 81 And the price has just been dramatically reduced to only 29 95 The Sinclair ZX Printer offer full alphanumericsandhighly sophisticated graphics A special feature is COPY which prints out exactly what is on the
61. dd 40p P P 2X81 with 16K RAM Also many programs 55 2 80 81 40 key Keyboard 15 Both items in good order Phone Atherton 879413 af 5pm FIVE ZX 81 graphics games YAHTZEE PONTOON MOONLANDER NINETYNINE BLASTOUT Tape 4 00 Listings 1 00 each Many others availabl including SOCCERFILE s details Adrian Boone 1 Church View Tobermore Magherafelt Derry ZXB1 64K USEABLE RAM PIA EPROM professional keyboard and case incl 6 spare keys and Space ber Programs Books value 30 Cost over 260 Sell for 200 o n o Tel 0642 782719 SINCLAIR 2 81 with Keyboard Bleeper Sinclair 16K RAM pack manual and two books and assorted micro computing magazines 100 o n o Ring Stevenage 721659 Herts 2 81 STORE SORT PRO GRAMME 16K Store sort and order 100 s of items of information and amend as required Tape and instructions 4 95 J Blackford 63 Eitisley Avenue Cambridge 3 SINCLAIRUSER July 1982 ADVENTURES 8 00 ZX BUSINESS SYSTEM ZX AUTOCODER prices inci VATR and Please send CONTROL TECHNOLOGY Gloucester Road Gee Cross Hyde Cheshire SK amp 0G 081 388 7987 SUPER SOFTWARE AVAILABLE FROM CONTROL TECHNOLOGY NEW RELEASE Trident Acorn Atom Death Race 2000 Vic 20 NY Air Traffic Control ZX81 Warlords Vic 20 Astro Battle Zone Moroids Vic Acorn Atom Breakout Vic 20 Maze of Death ZX81 Please send
62. dice game Cassette GTI Chess Psion Hardware required ZXB1 16K RAM Price 6 95 Programs Chess Chess Clock Description Fast efficient machine code a graphic display of the board and pieces plus six levels of ability combine to make this one of the best chess pro grams available The Chess Clock program can be used at any time Hardware required ZXB1 ZXBO with BK BASIC ROM 16K RAM Price 4 75 Programs Perilous Swamp Sorcerer s Island Description Perilous Swamp rescue a beautiful princess from the evil wizard Sorcerer s Island you re marooned To escape you ll probably need the help of the Grand Sorcerer Cassette G13 Space Raiders and Bomber Psion Hardware required 2 81 16K RAM Price 3 95 Programs Space Raiders Bomber Description Space Raiders is the ZX81 version of the popular pub game Bomber destroy a city before you hit a sky scraper Cassette G14 Flight Simulation Psion Hardware required 2 81 16K RAM Price 5 95 Program Flight Simulation plus blank tape on side 2 Description Simulates a highly manoeuvrable light aircraft with full controls instrumentation a view through the cockpit window and navigational aids Happy landings Education Cassette E1 Fun to Learn series English Literature 1 ICL Hardware required ZX81 16K RAM Price 6 95 Programs Novelists Authors Description Who wrote
63. disaster strikes Hazards include asphyxiation radiation escaped biological specimens and plunging into a Supernova STARTREK This version of the well known space adventure game features variable Klingon mobillity and graphic photon torpedo tracking PRINCESS OF KRAAL An adventure game BATTLE Strategy game for 1 to 4 players KALABRIASZ World s silliest card game full of pointless complicated rules CUBE Rubik Cube simulator with lots of functions including Backstep SECRET MESSAGES This message coding program is very txip jf MARTIAN CRICKET A simple but addictive game totally unlike Earth cricket in machine code The speed is variable and its top speed is very fast Cassette 3 costs 5 CASSETTE 4 ZX SCRAMBLE machine code with 3 stages L GALAXY INVADERS machine code Fleets of swooping and diving alien craft to fight off SNAKEBITE machine code Eat the snake before it eats you Variable speed very fast at top speed 7 games for 16k ZX81 Bomb and shoot your way through the fortified caves 6 of the 7 games are in machine code because this is much faster than Basic Some of these games were previously available from J Steadman Ci INVADERS machine code GUNFIGHT machine code LIFE machine code A ZX81 version of the well known 3D TIC TAC TOE Basic Played on a 4 x 4 x 4 board this is a game for the brain it is ve
64. dump to the printer Once again it costs 5 50 The Picturesque ZX MC is another sophisticated monitor it is rather like a separate operating system You cannot use it with any existing machine code programs as it uses low memory and has its own stack in high memory It has its own loading and saving routines which operate at twice the speed of the 2 81 The program is complete with a comprehensive manual for 7 50 but I believe its incompati bility with other programs is a serious disadvantage The Taurus Machine Code Moni tor is placed above RAMTOP and is available as a cassette and also in EPROM form as part of its 16K RAM pack system With the latter you can switch from 14K RAM plus 2K monitor to the full 16K RAM Apart from the usual functions it has a helpful hex calculator and a facility to create REM statements of any length It also has a comprehensive manual at 7 50 in cassette form and the RAM pack system costs 48 Bug Byte 98 100 The Albany Old Hall Street Liverpool L3 9EP ACS 7 Lidgett Crescent Roundhay Leeds 188 Campbell Systems 15 Rous Road Buckhurst Hil Essex IG9 6BL Aylesbury ZX Computer Club 12 Long Plough Aston Clinton Aylesbury Bucks MicroGen 24 Agar Crescent Bracknell Berkshire Picturesque 6 Corkscrew Hill West Wickham Kent 988 Taurus 47 High Street 567 686 Baldock Herts SINCLAIRUSER July1982 allows up to six players Brith the mach
65. e absorbs the shock The second method is simpler and cheaper and just as effective All that you do is to take a piece of Blutack and place it on the RAM above the edge connector When you plug in the RAM it is held to the computer by the Blutack The third way to stop RAM wobble however does not concern the Sinclair RAM but the Byg Byte RAM Initially there is nothing wrong with the RAM and it is a very good alternative to the Sinclair RAM but the case is about three times the size it SINCLAIRUSER July1982 should be and so it pulls the connections apart The answer is simple just remove the case Giles Colborne Galampton Devon Stopping whiteouts I WAS very interested in your article on the ZX 81 16K RAM pack in part icular the part which stated that the computer can suffer from whiteouts due to the fluctuations in the mains supply I have found that to be an annoying problem especially when loading a program which takes more than four minutes to run I have heard that is due to the voltage spikes in the grid over loading the memory and re setting it to the input mode leaving the mode K on my screen which has happened to me I know that this is the problem as the same tape and equipment will record perfectly during the times when the grid system isnot being used a great deal ie before 8 30am and between 2 pm and 4 30 pm It is not always convenient or possible to work on my computer
66. e adds however that something will be announced before the end of the year They decided to make the move they had also been tempted by the money Clive Sinclair was making Altwasser 25 gained a degree in engineering at Trinity College Cam bridge and went to work for a micro based automation company in Worcester but found the organisa tion too limiting After 18 months he left and joined Sinclair Research in September 1980 He did some work on the develop ment of the ZX 81 and after its launch in 1981 he was made res ponsible for computer research which involved him in the design of the hardware of the Spectrum Altwasser has also been writing software for the ZX 81 and his Cam bridge Collection has sold 30 000 copies Before joining Sinclair he had a little knowledge of computing own ing a TRS 80 and having run a We had plenty of Sinclair but at the freedom working at end of the day if a decision needed to be made there was one man who took that decision now because their major project for the last nine months the Spectrum had ended and like many other peo ple they wanted to be their own bosses We had plenty of freedom work ing at Sinclair but at the end of the day the company was run by one man and if a decision needed to be made there was one man who took that decision Altwasser says He and Vickers add jokingly that 52 course in teaching Basic Vickers kno
67. e simple machine code and in corporate them in a Basic program Itis not too soon to be thinking about your next machine code challenge Figure 3 RUN COMPLETE PROGRAM LISTING ic and Machine Code M 7 FAST 5724 CLE 43 200 THEN LET 90 99 an FASE SER LORIN PRINT 12 TE 2588 THEN 250 SR 55 LE VBHHBHHHHHHHHHHHHHHHHHHHHHHHHHHM 58 55 HH 188 2 LET 130 LE REPLAY 3 LET LET 1 1 THEN RUN 6397 148 i20 6 cus 386 PRINT AT 1 10 5 BRINT Bee LET U Us INKEY S CINKEY 16 PRINT s275 38 LET A 578 IF PEEK 0 3 OR PEEK W 82 tET THEN 108 82 IF 5 R110 6 A89 PORE Usu 23 s Rai ce THEN POKE 388 55554 238 8 52 299 IF 52276 THEN GOTO 408 LET CINKEY 6 CINKEY 318 SR T 8 7 32 5 OR PEEK U 400 21 0 ESTERM RE u 282 THEN 100 PERY 38 PORE 23 1 5 100 THEN LET 228 THEN RUN 45 IF 52180 THEN LET 230 SINCLAIRUSER July 1982 63 Win a printer and a Memopak 64K We thank readers for all the entries to our previous competitions No matter what the subject it seems that readers of Sinclair User have little difficulty in meeting the requirements Many of the tie break lines are most ingenious For our fourth competition we again off
68. e assembler program is similar to the Basic ROM in the ZX 81 The ROM scans the stops with an error code so it is not difficult to build a syntactically correct source program There is at least one bug in ZXAS the SUB A n instruction does not work but it can be replaced by AND A SBC which does the same ZXAS is a remarkable program and is excellent value at 5 The only other ZX 81 assembler I have encountered is produced by continued on page 42 41 E continued from page 41 ACS Software It is similar to ZXAS in size and operation with instructions entered in REM statements and labels available in the form Q 1 Q 255 Data must be entered in decimal rather than hex I prefer decimal and there is a useful DFB function which allows you to specify the contents of a particular byte during assembly so you can have messages embedded in your machine code The assembled listing eri is slightly different from are given decimal Added Dk opcode and data and then the mnemonic The ACS assembler is also excellent value at 5 50 and the use ofeither this program or ZXASis the single biggest step to proficiency in machine code programming Neither program sets out to teach assembler so a book will also be needed I use the thorough but expensive Programming the Z 80 by Rodney Zaks but there are now several books available specifically to the printer and you have to use the break key to r
69. e by Sargon clinched it That is interesting because I have a version of Sargon on my Video Genie computer and I have found it be be of reasonable standard I shall include some of the many games which have been sent to me when I have played them and can comment on them One reader has sent a letter saying that he did not know chess games were im plemented on such small computers he must be surprised Thope you can send me details of anything to do with chess or mind games in general Some comments on adventure games would be most helpful as that is my interest and I would like to know how other people feel about them 59 HAVE YOU HEARD A ZX81 BLEEP ADD A NEW DIMENSION TO YOUR KEYBOARD The 2 81 provides feedback missing from touch sensitive keyboards Makes programming faster more accurate 198 ZX81 characters bleep in fast and slow modes Fits inside case no trailing wires Easy installation Simple plug in connections No soldering required no risk of damaging ZX81 Also suits many full size keyboards Illustrated instructions supplied oko o o x ok ONLY 8 95 INCL VAT P amp P READY ASSEMBLED on off switch available at 1 extra Cheques amp to FULCRUM PRODUCTS Hillside Steep Lane Findon W Sussex 0UF TAURUS COMPUTER DEN 47 High Street Baldock Hertfordshire 507 Telephone O462 893900
70. e game we know 32 zones thrust and alti Holiday Closing Shop Open Our shop will only 9 30 5 30 be open on Mondays Closed Thurs Fridays and Saturdays S A E Brings between 28th June and Catalogue 16th July SORCERER S CASTLE SUPER SUMMER SALE NEW OR GENUINE REDUCTIONS MICROWARE 46 SINCLAIRUSER July1982 Ityou write a pr ich is exceptional please submit it to us We will offer a royalty if it is suitable Payable to MICROGEN 24 Agar Cres Op P amp P toallorders hardware world Kempston keyboard KEMPSTON Electronics has produced a micro miniature version of the ZX 81 keyboard with real keys It is the same size as the original Sinclair keyboard and so can be placed on the top of it It is only half an inch high and its black keys blend well with the ZX 81 The keyboard can be fit ted by opening the case and removing the original leads to the sockets on the PCB and replacing it with the leads from the Kemp ston unit The company also pro duces an Educase which exposes the printed circuit board to the naked eye for students and teachers to see through the clear plastic cover It ideal for demon strating the working of a computer the back can contain a parallel port complete with a demon stration program to run Centronics printer Unfor tunately there are Sinclair graphics The keyboard costs 22 50 Educase
71. e month of despatch it is unlikely that we will be using your submission SINCLAIRUSER July 1982 Address ESSENTIAL PROGRAMS ALL YOU NEED TO SIMPLIFY COMPLEX PROGRAMMING 1 0 16k SPECIAL OFFER BUY ANY TWO PROGRAMS FOR ONLY 11 50 OR ANY THREE FOR 1500 THE ABOVE PROGRAMS ARE ONLY A SMALL SELECTION FROM OUR WIDE RANGE OF 2X SOFTWARE ALL OF WHICH IS AVAILABLE THROUGH THE ZX SOFTWARE LIBRARY _ SAE FOR FULL DETAILS CHEQUE OR P O TO PSS 112 OLIVER STREET COVENTRY CV6 SFE SINCLAIRUSER July 1982 ZX81 users need more memory please rush me the fully assembled tested and guaranteed BYG BYTE 16K RAM PACK Make all cheques amp PO s payable to Phoenix Marketing Oaklands House Solartron Road Farnborough Hants Tel 0252 514990 FULLY INCLUSIVE PRICE 25 00 OPENING SHORTLY DEPT SU A retailer for Sinclair accessories in the Yorkshire Lancashire Humberside area We are situated close to the M1 amp M62 motorways and offering easy parking As well as a complete range of hard and software our service department can repair modify or fit a wide range of accessories For further details of these and many other services phone PHILIP COPLEY on 0924 272 545 Manufacturers of accessories looking for a retailer in our area are invited to contact us Hours of business MONDAY to SATURDAY 10am to 8pm
72. ecor ded Only 3 00 cheques PO payable to A R Hill 29 Trimdon Ave Acklam Middlesbrough Cleveland 795 BLU 2 81 16K ARCADE GAMES M C Missile Command and Galaxians 4 95 M C Asteroids Invaders 4 95 M C Falklands Islands action packed adventure at 4 95 all on cassette Magnum computing 3 Wensley Close Harpenden Herts WANTED 2 80 81 Vic and Atom books price for good condition S a e for buying selling lists or books direct to Allan Guy 24 Woodside Drive Cottingley Bingley BD16 1RF 2X81 16K RAM Sinc Built Adaptor Manual DK4K ROM iterature Software including Chess Startrek and many more Prog Book 1200 n o the lot v g c Tel Wokingham 782947 after 6pm 2 81 MEMOTECH 48K Module c w PSU Cost 140 used once only Will accept 90 0 n 0 Phone Newdigate STD 030677 274 after 6pm 2 81 MICRO COMPUTER with 16K RAM and 20 worth of soft ware on magnetic tape with manual very good condition hardly used 85 Tel Barnsley 0226 42143 between 2 30pm to Bpm for further information FOR SALE 2 80 8K ROM 16K RAM manuals Many pre recorded programs inc Sinclair business household Chess Labyrinth al perfect working order Accept 120 Tel Northampton 0604 831078 2 81 KITS Cure Top Line Slant and Ram Pack Wobble 2 95 Inverse Video Module 2 95 Built 3 55 Repeat Key 3 75 Built 4 95 Kits ex stock Please a
73. ed below 39 Bomythme Backgammon 3 Space Racers Bomber 4 Fight Senat 1 a cheque postal order to Sinclair Research Ltd for Please charge my Access Barclaycard Trustcard no Please delete as applicable pennas Address Cassette B3 VU CALC Psion Hardware required ZX81 16K RAM Price 7 95 Program VU CALC Description Turns your ZX81 into an immensely powerful analysis chart VU CALC constructs generates and calculates large tables for applications such as financial analysis budget sheets and projections Complete with full instructions Cassette B4 VU FILE Psion Hardware required 2 81 16K RAM Price 7 95 Programs VU FILE Examples Description A general purpose infor mation storage and retrieval program with emphasis on user friendliness and visual display Use it to catalogue your collection maintain records or club memberships keep track of your accounts or as a telephone directory How to order Simply use the FREEPOST order form below and either enclose a cheque or give us your credit card number Credit card holders can order by phone simply Camberley 0276 66104 or 21282 during office hours Either way please allow up to 28 days for delivery and there s a 14 day money back option of course ZX8l SOFTWARE Sinclair Research Ltd Stanhope Road Camberley Surrey 615 3 5
74. emittance encioved Less Special Quantity Discount liu Smith adds to micro range WH SMITH expects to be selling another computer by the end of the year It is talking to a number of manufacturers about stocking their micros to add to the ZX 81 which it began selling last September John Rowland market development manager is giving nothing away about which machine it might be but expects a decision to be made in August It is the next major step inthe company s move into the home computer market which it sees as a major growth area It is already extending the number of branches selling computer goods and increasing the amount of selling space particularly in the larger branches We sell 50 lines of software and are increasing that all the time We think we are ready to take the next step in offering a new machine Rowland says He added that when the new product is launched it is hoped it will be accom panied by a full range of software He expects that by next year the company Clive to run in half marathon CLIVE SINCLAIR s energy seems to be endless Not only is he able to master mind one of the most suc cessful computer com panies in the world he has enough strength left to run marathons He has already run one distance of more than 26 miles and now is to take part in a half marathon being organised as part of the 1982 Cambridge Festival
75. emory Extension The 64K Memopak is pack which extends the memory of the ZX81 by a further 56K and together with the ZXB1 gives a full 64K which is neither switched nor paged and is directly addressable The unit is user transparent and accepts BASIC commands such as 10 DIM A 9000 BREAKDOWN OF MEMORY AREAS 0 8K Sinclair ROM 8 16K This section of memory switches in or out in 4K blocks to leave space for memory mapping holds its contents during cassette loads allows communication between programmes and can be used to run assembly language routines 16 32K This area can be used for BASIC programmes and assembly language routines 32 64K 32K of RAM memory for BASIC variables and large arrays With the Memopak 64K extension the 2 81 is transformed into powerful computer suitable for business leisure and educational use at a fraction of the cost of comparable systems Video page is both memory and bit mapped Video page can be located The number of video pages is limited only by your RAM size each page occupies ott gives flashing characters numerals etc The pack comes in an elegant aluminium case anodised black and 16K RAM 26 00 3 90VAT 29 90 Ltd 64 68 69 10 31 79 00 ComingSoon xv Please make Please send me Price No Total cheques payable to
76. en it and the ZX 81 1 have been able to deal with only a few subjects There is so much more to learn about the Spectrum from the manual that it would become a series if I did not stop now The Spectrum is real value for money and easy to use It has some peculiarities but they do not seem important when you look at what it can offer With disc networking facilities and RS232 interface it is a great improvement on the ZX 81 but it cannot replace it as the price of 129 95 will still be a little daunting to those who want to try a computer for the first time gu THE BEST ZX81 BOOK 4 N Far and away the best once again Linsac has produced the Fe TheZX81 Companion is a most professional product with many 08 08 good illustrative programs tips and warnings Education Equipment October 1981 Bob Maunder sattempt to show meaningful uses of the machine is brilliantly successful thoughtfully written detailed and illustrated with meaningful programs conclude the book is definitely an outstandingly useful second step for the ZX8 1 user Educational ZX80 81 Users Group Newsletter September 1381 Bob Maunder Send your cheque for 7 95 includes UK p amp p to LINSAC ker Rond Linhor LINSAC SU vascos tss ses 5880907211011 Price 7 98 Music Music 2 10K Nighimare Park
77. en the computer answers it also signals the start and finish of a LOADing or SAVEing program It may also be programmed to bleep in a program for simulating an explosion by using a PAUSE greater than 5 The KAT costs 8 95 if you fit it yourself and 10 95 if you send your ZX 81 for it to be fitted TV Services of Cam bridge Ltd Chesterton 48 Mill Frenches Road Cam bridge CB4 3NP 2K monitor EPROM TAURUS Computer Design has a 16K RAM pack which also contains a 2K monitor EPROM for writing machine code pro grams on the ZX 81 It replaces the top 2K of RAM when the switch is thrown on the front of the program All is contained in a metal box 6 x 2 x l Ain which attaches to the ZX 81 edge con nector via a ribbon cable to prevent crash ing the program due 10 the movement of the ZX 81 The 16K RAM pack costs 59 95 with the monitor and 49 95 without from Taurus Com puter Design 47 High Street Baldock Herts SG7 6 Tel 0462 893900 The 16K RAM pack from Taurus Computer Design RAM pack and you can enter the machine code monitor by a simple USR command The monitor provides facilities such as hex arithmetic break points copying data from one place to another decimal to hex conversion fill memory display port read and write plus many more The monitor will write a suitable length REM statement at the beginning of a program so that your machine code rou
78. er a printer but this time couple it with a 64K Memopak from Memotech of Oxford In line with our policy of fitting the competition to the prize we would like you to write a program for 48K RAM All entries must be on cassette and accompanied by a typed or beautifully handwritten isting Your entry must reach us by July 12 As a tie break should one be necessary we want you to write a slogan beginning with the words I bought my ZX 81 because The usual rules about the editor s decision being final and employees of ECC Publications being ineligible apply SINCLAIRUSER July1982 ZX81 SOFTWARE ALTERNATIVE PROGRAMS 1 16K FOR THE MORE DISCERNING ENTHUSIAST Make cheques ete payable t FUTURESOFT 38 PENSHURST ESTATE PRINCE OF WALES ROAD LONDON It is hard enough to look at an amorphous hydrosilicon blob from Psi never mind swing a deal with one But when they ask to pick your brains do you really know what they have in mind Trader is a new concept in 2 81 games It is a graphic adventure so big that it filis your 16K Ram three times You are an intergalactic trader and the life is tough the bargaining hard You can make a fortune or end up spaced out in a Deltan hellhole Trader 48K of adventure that will run in your 16K Ram It costs 10 50 inclusive Send SAE for more details of Pixel games PIXEL Pixel Productions 39 Ripley Gdns London SW14
79. ere books are marked once a lesson the incorrectness of what they have done may become apparent only at the end of the lesson or next day Once we have the child under standing counting to certain total speed practice becomes important in helping the child to rely less on physical cues of number and begins 10 depend on their internal memory of where they are in the count The games should show varying numbers of shapes quickly on the screen for which a running total has to be kept by the child to be entered at the end of the run HISSING SID is an example of such a program Snakes appear on the screen varying numbers each time A total is input at the end which is checked figure three There is plenty of fun while learning to count with this program especially if it is altered to print the total at the end after a short pause to give children a chance to shout the answers They love to see who can be first with the correct answer Figure four shows how to do this This program can be altered in both speed of display and numbers of snakes For larger numbers alter line 20 and for less time between displays alter line 100 If you make it long enough and quick enough it becomes fairly testing even for adults I wrote a similar program on the Pet at school and tried it on my own class as well as the class of a colleague My class by now fairly blase where micros are concerned some of them prefer me
80. erted into the drive It can fit in the palm of your hand and can provide up to 200KB of memory on one disc The power supp lyis 12V and 5V andit weighs only 0 47 kilogram mes The drive provides a standard interface so that it can be used with disc controllers already available The price in quantity is 50 and details can be obtained from BATS NCI Ltd 375b Regents Park Road Lon don N3 1DG Tel 01 349 4511 SINCLAIRUSER July 1982 REGISTER brings together the Sinclair ZX world within one cover DIRECTORY OF 350 SUPPLIERS Schedules of SOFTWARE programs Games Educational Business Computer Enhancement and Domestic sub divided into a further 30 categories Extensive list of HARDWARE items for sale Index of ZX PUBLICATIONS References to reviews of ZX ware USER CLUBS when and where to meet Much other useful information including details of other services and programs notes for new users advertisements Price 2 95 from YOUNGS ZX REGISTER 2 Woodland Way Gosfield Halstead Essex CO9 ITH The register is being ised and re issued Ifyou want your new product tobe inthe Register contactus We can also arrange for you to be on PRESTEL 2X81 ADVENTURE SPECIALISTS C2 VOLCANIC DUNGEON HANGMAN 4 50 VOLCANIC DUNGEON Rescue you can the Elfin Princess Mythical monsters pits ery caverns diminishing strength and water make your quest anything but easy FULL 1
81. et wisely and you may make a fortune Success depends on many factors and not just luck FULL 16K PROGRAM ORDERS Plus 50 PEP or large S A E for list to CARNELL SOFTWARE ASTAUNTON ROAD SLOUGH BERKS 512 INT eate are siso avaiable from BUFFER MICROSHOP STREATHAM LONDON SINCLAIRUSER July 1962 Both RAM packs use zame neat ABS plese cse only 27 47 16k pan 222 95 RAM 59 95 Quali ty SoPtuare V GALAXY INVADERS PROGRAM Now FAMILY FUN No 111K RAM only GRAPHICS STARTER PACK Four We ease adi Xy per in British hes sere tom Xp BRIDGE SOFTWARE SU se FERNWOOD MARPLE BAIOGE STOCKPORT CHES SKG Send e for forth famous Turtle programme PRIMARY EDUCATION 4 95 only indi p amp p Hsin Seuil Testa Seres qui XY coordinates Count Equations Areas Guess a Volume Angles Upstairs Downstars Music notes See saw Wipe out Spell ts EDUCARE Mastermind Number shoot 26 more Please send me Copies Educera s 50 T Te EDUCARE i enclose cheque postal order for 1390 Soane St lero London swixsay Address Lat you chad benefit soriy Send now 49 ZX81 SOFTWARE ALTERNATIVE PROGRAMS 1 16K FO
82. eturn to Basic Machine code can be entered and individual bytes changed using hex This program price 4 has been available since June 1981 and has perhaps been superceded by some of the others on the market The Aylesbury ZX Computer Club has decided courageously to enter the software fray with its disassembler It is very large program 14K and runs a little slower than the others The display which can go to screen printer both is unusual addresses contents and mnemonic data are given in both hex and decimal and the display allows one line for each byte There is also a facility to enter machine code from address 30000 in either hex or decimal and an Edit function to alter byte or copy block of bytes from one area of RAM o another It is good value at 3 50 plus 50 pence for postage and packing Bug Bytes ZXDB disassembler can be used in conjunction with its In some ways the assembler program is similar to the Basic ROM in the ZX 81 for machine code programming on the ZX 81 Disassemblers convert machine code into mnemonics making it easier to analyse and amend The ACS disassembler can be used at the same time as its assembler and provides mnemonic listings in the same format All addresses are shown in decimal and destination addresses are shown for relative jumps rather than the displacement which is an excellent idea the other disassemblers have additional bells and whi
83. fferent features that it is difficult to list them all functions are accessed via Basic USR function calls Each For example function has an entry address which must be quoted after the 2 USR keyword All of the functions can be used in program AUTOMATIC TAPE TO TAPE COPY You can copy any data file regardless of your memory capacity a C90 has approx 200K bytes on it as it is loaded through the Sinclait p ok o x There is an extension board on the rear to plug in your RAM pack larger than 16K if required The unit is supplied with commo one special cassette lead are available at 1 each statements or in immediate commands i e both statements with line numbers and commands without them DIAGNOSTIC INFORMATION to assist in achieving the best 322 below recording settings COMPREHENSIVE USER MANUAL TAPE DRIVES INCLUDED IN PRICE We supply and guarantee its compatability a Tape Drive ZX99 SOFTWARE E that works with your computer We now have available Editor 99 quality word processing COMPUTER CASSETTES program including mail merge supplied on cassette for 9 95 Also following soon will be We supply quality screw assembled computer cassettes Stock Control Order Processing Please enquire for any not shown Sales Ledger Debtors Ledger Business Accounts Tex Accounting gt lt
84. fits inside The tough ABS injection moulded plastic case measures 8 x 14 x 2 and hooks up to your ZX printed circuit board in minutes No technical know how or soldering is required The ZX16K Memory Module will fix inside the case using the new Adaptor Board at 975 or the Motherboard By removing the ZX PSU from its case this can also be fixed inside We will carry out the installation work free of charge if required All the Sinclair ZX81 keys are duplicated on our layout with extra shift and new line keys The professional momentary action key switches have a guaranteed life of 10 operations The unit is fully built tested and comes complete with a money back guarantee INSTALLATION Simply unscrew the ZX printed circuit board from its case and screw it into the FD Case AD Code zxu MOTHERBOARD We also manufacture a mother board which allows expansion to the ZX memory and 1 0 facilities WITHIN the case as well as our power supply unit and reset switch Picet Amount Fuller FD System 42 Keyboard amp case 39 95 FD System Motherboard 15 95 FD 16K Memory Module 29 95 64K Memory Module 78 95 5 FD PSU 9 Volts at 2 amp 1295 648 FD Shipping and Handling 2 50 3 o Mail to FULLER MICRO SYSTEMS 9 The ZX Centre Sweeting Street Liverpool 2 England U K 2 SAE for more details Enquiries Tel 051 236 6109 Name Address
85. gram loop Delete lines 10 20 30 and 40 of the scroll down test program and add lines 7 10 20 and 50 as shown in figure one Line 7 prints the game title on line 20 of the screen that is not scrolled since our routine scrolls only 19 lines Lines 10 20 and 50 produce the approaching runway effect study this three line loop carefully Then run the program and you should see if all is well the runway approach Press BREAK before the runway reaches the bottom of the screen and you will have a VDU picture similar to that shown in figure two Our main program loop incorporating the machine code works Now add the aircraft path and some means of steering it I have SINCLAIRUSER July1982 chosen an asterisk CHRS 23 to represent the position of the craft at any time Since we will be POKEing the asterisk into the display file we will have to locate it as described previously by PEEKing system variables 16396 and 16397 and using those to define a variable W Then add the following lines to the developing program 4 LET V 411 5 LET W PEEK 16396 256 PEEK 16397 30 LET V V INKEY 8 INKEY 5 5 40 POKE W V 23 Variable W in line 5 defines the start address of the display file and variable V in line 4 is the dis placement to be added to position the asterisk in the correct place on the screen The POKE statement in 40 places the asterisk on the screen directly be
86. hassis 19 50 All are obtainable from Capital Computers Ltd 1 Branch Road Park Street St Albans 4RJ Memory board from Fuller FULLER Micro Systems has added a new board to its range of equipment whch can fit inside its keyboard case It starts as an ordinary 16K board supplied with the in dustrial standard 4116 chips but if you decide later that you need more memory you can upgrade the board to a full 64K by changing the RAM chips continued on page 48 47 continued from page 47 and a few straps on the same board The 16K PCB will fit into any motherboard which provides sockets for boards to plug into and costs 39 95 To upgrade it to full 64K will cost another 45 for instruc tions and the 64K chips to fit to the board The complete Fuller Micro Systems range can be seen and purchased from The ZX Computing Centre Sweeting Street Liverpool 2 TV Services bleeper TV SERVICES of Cam bDridge has a neat little keyboard bleeper called the KAT keyboard audio tone The device can be fit ted inside the case in the space beneath the key board or in any other place for that matter as it is an extremely flat PCB and piezo electric loud speaker There are only five soldering connections to make to the ZX 81 PCB as the rest is ready assembled If that makes you nervous the company will fit it to your ZX 81 The bleeper gives two tones one when a key is pressed and one wh
87. he ZX 81 Taking the lid off the Spectrum The keyboard is an input output mapped device as on the ZX 81 and along with the the ZX printer which is the same for the ZX 81 and the Spectrum network RS232 interface discs loudspeaker tape interface and border colours require only one address line to work That means that you must make all of the lower five address lines a binary 1 to use your own devices The input output map access has been improved greatly however with the addition to the Basic commands of IN and OUT They give an instruction IN or OUT A c where registers BC give an address from 0 to 65535 The memory mapped addressing of the RAM ROM occupies 0 16K and the RAM 16K 32K on the basic 16K model There is provision for an extra 32K board to be plugged in to IC sockets at the back of the printed circuit board The 48K version will have the board fitted but to add it The Spectrum is real value for money and easy to use It has some peculiarities but they do not seem important when you look at what it can offer used one after another it tends to slow the input speed as you are constantly swapping hands For instance RUBOUT and the cursor movements use CAPS SHIFT and are SYMBOL SHIFT It would have been a better idea to put both on the left hand side as they often need to be used together and could be pressed with one hand while the other searches for the appropriate key 14
88. id kept appearing to say I had it all wrong and when I attempted to put it right everything went from bad to worse The trouble is that I am used to a Unnecessary though a ZX 81 may be what a marvellously clever and obedient little chap it is me the square of the cosine of the price of one egg should I ever want it Well you never know I was glad too that the manual catered for the eventuality of my housekeeper rushing in full of concern and crying in that delightfully old fashioned way of hers Glory be eggs have gone up to 61 pence a dozen What worries me though is how am I going to tell the kind soul that thanks to my handy little computer I 26 typewriter keyboard not one which moves things about and has about 12 instructions per key and erases backward to boot I knew you could pull out the plug and start again but that seemed a little drastic It reminded me of my one and only ski ing holiday when learned to negotiate a slope more or less but not to stop do that I would throw myself into the first convenient snowdrift but I always thought there must be a better way D Eventually it all came clear to me and 1 was chugging along again happily At one point I even thought that together the computer and I would crack that eternal problem of the length of a piece of string but it proved to be more a matter of whether Mr Smith was shorter than Mr Smythe I don t th
89. ide the game appearance strategy and rules This must be considered in the context of scroll down since we intend to use the routine we have developed Produce a series of statements concerning the program flow and operation For a program as small this a full blown boxed chart is considered unnecessary by the author Using the statements build up the program piece by piece testing as you proceed for the desired effect Soak test the entire program for several hours by letting your friends acquaintances and children loose on it If there are any undiscovered bugs they will find them THIS FINAL article we Playing games with machine code In the last of his three articles Mike Biddell looks at ways of using machine code in game simulation of the game plot Itis war time and you are flying a transporter aircraft to land supplies behind enemy lines As the runway approaches you can see that it is mined but it is too late at that stage to pull up since your airspeed is too low You have therefore to land and taxi around the mines to take off again and see the runway recede If you hit a mine or go off the side of the runway the aircraft crashes It sounds exciting so let us proceed to the statement portion of our development plan and produce a series of statements about how the program might flow and operate Main program loop using PRINT AT function to produce the runway element Call USR t
90. ine doing all the Sorry NO cheating allowed Best described as TRADING ADVENTUR it s a PAIN Written for MASOCHISTS the game starts INNOCENTLY with 40 000 in your hand THEN You re YOUR OWN You choose CREW SHIP STORES and CARGO You even choose where to go and either make a FORTUNE or FAIL to SURVIVE GO CAREFUL you have 200 Bytes left from 16k 140 WILSDEN AVE LUTON BEDS Tel Luton 454456 The ultimate SINCLAIR ZX 81 16K DATABASE FILING SYSTEM by DALE HUBBARD Fed up with boring games make your ZX81 work for you The one you ve been waiting for Cassette based Clear menu operation Facilities include sort search list delete change total numeric field save and load file line print etc Complete with demonstration file and full instruction application leaflet Requires 16K Ram pack Applications Recipe file Stamp coin collections Inventory Control Employee Data Record Collections Magazine article catalogue May be used for any application where fast access is required to stored information Access accepted ONLY Send cheque or P O or credit card number to 5 95 FULLY INCLUSIVE GEMINI MARKETING LTD 29 Quay House Quay Road Newton Abbot Devon TQ12 2BU EE ess OR telephone us with your credit card order egt on Newton Abbot 0626 62869 een Tee DESPATCH BY RETURN ING RESENTII FHE NEW IF YOU ARE like many
91. ink I had that correct By then my earlier struggles had worn me out and besides there was a good film about to start on the other channel My studies may not be very advanced but 1 see now how one could become very involved in all this From the start I have wondered what possible use a computer such as my son s could and I still don t know but who cares Pressing buttons is fun Unnecessary though a ZX 81 may be what a marvellously clever and obedient little chap it is Do this and do that the manual says and the computer will do this and do that and it does what else in life is so simple and so satisfying Anyway 1 could not stop now kinds of fascinating things have caught my eye measles programs Venusians with eight fingers and no thumbs flowcharts and 1 must investigate If anyone wants me in the next few days please speak to the housekeeper SINCLAIRUSER July 1982 REA READ OUT PUBLISHING LTD THE ZX BOOK CLUB 8 Camp Road Farnborough Hampshire GU24 GEW Telephone 0252 510331 2 Telex 858001 GOWER The ZX81 is the world s biggest selling computer and just announced is its big brother the ZX SPECTRUM For value for money these two computers must be the best computer buys on the market but to get the most from them every owner and prospective owner needs a library of books for programs and operations Read Out has selec
92. ips DROPOUT 5 95 Exciting NEW arcade game Can you destroy the aliens before they build up in their atomic plies and overwhelm you Dealers enquires welcome generous discounts When ordering 2 or more deduct 1 00 Send S A E for Catalogue Tick bonets required Cheques payable to SILVERSOFT Name Address WANTED spectrum Micro Software Ali Arcade games run in 4K SINCLAIRUSER July 1982 RUBRA RINIOU S ITS NAME suggests Snap version of the well io LET P known card game but 88 LET Bec instead of cards the program has 40 FOR C three words club bar and ES LET REFR cherry which appear in random 70 IF A 0 THEN LET a puya mod two ead the Eon 80 IF A 1 When two words are the same eee the two players have to press their 110 IF INT C72 INT C72 THEN keys either Q or P as quickly as possible to score a point The game lasts for four attempts and the score for each player is displayed at the top of the screen It is a simple game but can be fitted into 1K RAM and is one of the few games of this size which can be played by two players NEXT C Sen was sent by Tim Crossley of York SINCLAIRUSER July 1962 31 32 UMBER CRUN js an interesting game which can fit on the basic 1K version of ZX 81 It the many slalom type the nem
93. ir User ECC Publications 30 31 Islington Green London N1 We will pay 10 for each program printed and 50 for each article which should be approximately 1 000 words long Copyright 1982 Sinclair User ISSN No 0262 5458 Origination at Outline Graphics Printed by Eden Fisher Southend Lid Distributed by Spotlight Magazine Distribution Ltd 1 Benwell Road Holloway London N7 01 607 6411 SINCLAIRUSER July1982 page 6 page 14 5 SINCLAIRVOYANCE We consider the future for retailing in the Sinclair market and its effect on suppliers 6 SCHOOLS SPOT teacher Dave Sayers writes about his experiences using the ZX 81 in his school 9 LETTERS More brickbats and bouquets from our readers 10 SINCLAIR USER CLUB As o Star Bargain to club members 14 SPECTRUM REVIEW Stephens Adams looks inside the new Sinclair machine likes what he sees 19 NEWS W H Smith s future plans ZX shows around the country and the sponsorship of the Cambridge half marathon 22 AMATEUR RADIO Julian Moss looks at the uses of the ZX 81 in radio shacks 25 NEW USERS Las month Nicole Segre told the story of the mother s lament of her son s new computer This month she tells how she fought back 28 READER SURVEY We ask you to tell us what you think of Sinclair User and the market for Sinclair products and spin offs 31 PROGRAM PRINTOUT Another eight pages of special programs with one for the Zx ao 41 PROGRAM AIDS Phil Garret
94. ive type of employment If no state whether student retired or whatever 3 Into which ranges does your income fall Less than 5 000 O 5 000 to 10 000 10 000 to 15 000 O 15 000 to 20 000 1 More than 20 000 O 4 Do you own a Sinclair computer 28 Whichone 2 80 ZX 810 Spectrum How long have you had it Less than one month to six months 5051012 months Longer than 12 months How did you buy it order WHSmithO Second hand O 1f you intend buying another model which one AT If not do you use someone else s yes no Do you intend buying one Which one 2 80 O 2x81 O Spectrum O yes no 5 Doyouuse any other system yes no Which one eee 6 Do you own any peripherals State makes Cassette player O RAM pack O Printer O Keyboard Motherboard Any other hardware O How did you buy them Mail order through Sinclair Usei Other mail order Microfairs O W H Smith O Other sources give detai SINCLAIRUSER July1982 us plan for the future and to ensure that we maintain the high standards which Sinclair User has achieved in its first three issues we would be grateful if you complete this questionnaire None of the questions is difficult and all information will be treated in confidence Please tick the boxes or write your answer in the space provided 7 Doyoubuya
95. k offer if not satisfied months warranty Your order is recieved at and ie despatched by 12 30 the eas ord ame day PLEASE SEND ME Quantity Price Total Date 16k 19 96 FUNT 47 Address Payment to PRETORIUS SYSTEMS Mail to B C M BOX 7977 WCIN LONDON ENGLAND 24 SINCLAIRUSER 1982 Nicole Segre finds that despite her reservations understanding the ZX 81 is only a matter of time Discovering the adult charms of the ZX 81 last month about the upheavals caused in the household by my son s purchase of one small seemingly innocuous electronic machine called ZX 81 What distressed me most was that he and his friends all mere babes in arms seemed possessed of a technical skill and expertise with regard to computers which left me feeling decidedly pass I have determined to remedy all that It is important in my view not only to keep up with the times but to teach all those uppity youngsters not to under estimate their mothers Accordingly 1 waited for a short pause between a game of Star Bash and a game of Clonk and obtained my son s permission to tinker with his Sinclair during those hours month abo at some length SINCLAIRUSER July 1982 when attending to his education kept him away from more pressing matters Is there anything I must not do I enquired anxiously it s all right he said Compu
96. later it will cost 60 which I think is expensive There would be no difficulty in adding extra ports to the memory map as on the ZX 81 above 32K on the basic version but for two things There is no RAM CS line so that the extra RAM can be turned off if required on the edge connector and the edge connector address lines have been moved to the outer edges so that it is incompatible with the ZX 81 The Spectrum has a 28 way double sided edge connec tor of the same style as the ZX 81 with the keyway on pin 5 That makes any input output device com patible with the 2 81 but any memory mapped devices would have to be rearranged The edge connector also has a number of new signals on it which are not explajned in the manual plus a video output and colour outputs for VDUs All the voltages used on the Spectrum are also brought out namely 57 5V 12V and 12V They are obtained from the same buzzing transformer as is used in the 16K RAM pack and most of that RAM pack seems to have been transplanted on to the Spectrum The obvious additions to the circuitry are the PAL colour mixer under the metal can which contains the video modulator and the fact that two crystal controlled oscillators are used one for the ULA which controls the screen among other things and the other for the colour mixer The 14mHz clock for the ULA is also used to drive the 2 804 microprocessor after it has been reduced to 3 5mHz Th
97. lly of writing new SAVE and LOAD routines in machine code The second method is slow and clumsy but it is easy to understand and the necessary software is mostly in Basic so will explain it as the preferential method The steps in outline are SAVE the data of interest on tape to prevent the program in the ZX 81 SINCLAIRUSER July 1982 program between entering the instructions or you will have to pull out the plug and start again Youare making the ZX 81 think that the whole program is one monster Basic line and if it attempts to LIST it all it becomes confused Entering 10 or whatever deletes the monster line in the usual way The data can then be SAVEd together with the display file and other odds and ends on tape The second step is to LOAD a new program and store it above RAMTOP The technique is very similar to storing data above RAMTOP which I have explained previously Be sure to move RAMTOP down as explained on page 168 of ZX 81 Basic Program ming before LOADing the new program The following routine copies a program above RAMTOP 10 J 16396 256 PEEK 16397 17509 20 PRINT J 30 LET K PEEK 16388 256 PEEK 16389 40 FORI 010 1 50 POKE K I PEEK 16509 I 60 NEXT I The routine PRINTs the length of the program J in bytes You should make a note of it because it will be needed later The data can then be LOADed from tape in the usual way The current program will of
98. low the runway The value of V was determined by trial and error The steering logic is in line 30 It uses inkey 5 10 decode keys 5 and 8 on the keyboard the keys with the left and right arrows That works on the basis that if inkey 8 then the whole expression inkey is given the value 1 true That applies to inkey 5 in the same way Thus if inkey 8 that adds 1 to variable V and moves the screen POKE one position to the right inkey 5 it is moved to the left Then run the program with these additions and you can steer the aircraft from left to right With its controlling logic you can steer it anywhere you like including off the runway We have covered items one and two of the main program speci fication and I have been doing all the work It would be excellent practice for you to add your own program lines and complete the program test them carefully as you proceed For those who feel less inclined to tackle the task a completed pro gram it is only one solution is presented in figure three Compare the additional lines to the rough program specification and you will begin to understand how it operates To be frank I have not yet managed to get the aircraft back off the runway Is it possible Perhaps with more practice I might make a better pilot In conclusion if you have followed the articles you have mini machine code loader and an understanding of how to writ
99. me Sufficient of the theory how are the ZX 81 assemblers used Bug Bytes ZXAS assembler is in 5K of machine code with a few lines of Basic to operate it The program sets RAMTOP automatically and loads itself above it so that assembler source programs can be loaded and saved separately Lines of mnemonics are entered in REM statements with multiple tions allowed provided they are separated by semi colons Up to 256 labels can be used in the form LO to L255 and comments may be pla after a Full stops are used instead of commas e g LD which makes typing i easier and numbers may be entere in decimal or hex When assembler is run you are prompted for the starting address for the resulting machine code Invariably I use a REM statement at the start of the program and compile the machine code from 16514 The assembler code is then displayed on the screen in the format source line number address in hex opcode and data in hex Z 80 mnemonic If there is an error the assembler There is a trade off between the speed of the final program and the time taken to write it though is highly error prone and time consuming if the program is substantial On the other hand an assembler program converts the mnemonic form of instructions which we can understand reason ably easily into machine code which the microprocessor can understand and execute In some ways th
100. nd continuously square by square FLASH or have two intensities of colour BRIGHT Thescreen takes up 6 912 bytes of the 16K memory and the system variables take up another 738 bytes The rest of the memory is not free for the user to use as 11 other areas float above location 23733 and can expand and contract as required by the Spectrum The program and variables are sandwiched in the middle of those so REM statements cannot be used for machine code There is an area spectrum radio however which can be used for machine code programming above RAMTOP which is ignored by the Basic and its length can be defined by the user The user definable characters area is stored above that so they can be kept from program to program There are many tape arrangements which can be made with the Spectrum The program strings or machine code can all be SAVEd LOADed and VERIFYd separately The variables and screen can also be stored on tape but cannot be VERIFYd As each is SAVEd messsage to start the tape recorder will appear and wait for you to press a key That is a very good example of the user friendliness of the machine and most of the errors appear with similar messages SAVEing or LOADing causes the border to flash red and green or red and blue depending at which part of the tape you are looking All of my tape programs LOADed correctly and I was surprised with the difference in speed betwe
101. nd fall off to land in a boat from where he is returned to the bridge to climb and try again Whether you use these ideas or not it isimportant to pay careful attention to what you want your program to teach and as he totalled them he finally answering addition questions delivered his answer in a very correctly Eachcorrect answer puts never to take for granted the idea positive way another span on the bridge As tbat children understand the logic Gone were the uncertainties he before they are adding blocks Of mathematics rine 1 179 FOR Is1 TO 100 FOR I 1 TO 19 189 NEXT I 50 FOR Jei TO I 198 GOTO 5 PRINT 20 NEXT J Figure 4 50 PRINT I 80 PRINT Change these lines 130 for 110 150 igure next 19 LET RND 10 10 140 next u 26 ccs 30 FOR 1 A Do not forget to delete line 150 20 PRINT S8 NEXT r 55 PRINT Figure 5 e INPUT SS IMPUT a THEN LET e PRINT WRONG WAS GA 6 PRI 98 FOR 1 1 TO 100 7 PRI 499 10 FOR 10 20 PRI SPACES 12 Se NEX CES Figure 3 10 LET RND 9 2 H 50 LET RND 8 1 15 20 INT RND 5 1 e n e A e NEX 40 INT RND 6 1 FOR 50 B 100 PRI 110 7 SPRCES HAMA 120 SA 130 3 135 148 3 5 FOR 1 70 iso IF s ie THEN 160 PRINT AT 18 1 178 PRINT BT 17 1 HOW SNAKES 180 IF S 1 AND D THEN coro 5
102. nswering problems and many special discounts on a variety of goods of interest to ZX owners Sinclair User will also contain stories about the club and its activities in each issue It is intended to build up the number of items which will be available at special prices to club members with a Star Offer each month Readers wishing to share the benefits of membership of the Sinclair User Club should complete the form below MEMBERSHIP FORM I wish to join the Sinclair User Club and enclose my subscription of 12 Send your coupons to Sinclair User Club ECC Publications 30 31 Islington Green London N1 8BJ Cheques should be made payable to i i Sinclair User Club 10 SINCLAIRUSER July 1982 3 off the Dean Electronics keyboard Sinclair For this month s bargain open only to members of the Sinclair User Club we are offering to reduce the price of what many people consider to be the best keyboard available for the ZX 81 the Dean Electronics keyboard It is simple to fit plugging straight into the ZX 81 after the built in keyboard has been unplugged It has 47 keys six more than the ZX 81 The extra keys can be used for whatever the owner wishes The normal price is 35 but we are able to offer the keyboard through Buffer Micro Shop for only 32 In addition the case which usually costs 14 50 is offered at 13 50 Membership cards must be shown or numbers mu
103. ntains TASWORD and TASWORD TUTOR This teaches you word processing using TASWORD No programming knowledge is required to use TASWORD 6 50 tui inciusive Allow up to 14 days delivery Please make cheques P O payable to TASMAN SOFTWARE 17 HARTLEY CRESCENT LEEDS LS6 2LL L Sinclair 2 81 microcomputer now at Cambridge Computer Store ZX81 Assembled 69 95 ZX81 49 95 16K RAM 29 95 new PRICE Printer 59 95 wew PRICE All units now in stock Wide range of books software and DCP packs also available in our Budget Micros department Cambridge Computer Store 1 Emmanuel Street Cambridge CB1 1NE Phone 0223 358264 65334 Also Acorn Atom VIC 20 Tandy TRS 80 ZX81 HEWSON CONSULTANTS 2 81 HINTS AND TIPS FOR THE 64K MEMOPACK LINE RENUMBER NEW X81 by Andrew Hewson 3 95 4 95 79 00 PILOT 5 95 NEW 16K MEMORY gt PROGRAMMERS 6 50 TOOLKIT 48 8K d WT f io 6195 STOP PRESS PUCKMAN 5 95 Oxon 100 SINCLAIRUSER July 1982 61 examine how our simple machine code routine scroll down can be used to good effect to produce a game simulation We will examine how a supporting program written in Basic can call the USR routine to maximum effect and how the whole program can be built and tested stage by stage A logical procedure to adopt at this stage is Dec
104. nysoftware yes no What types From where How much do you spend each month Do you have special monitor or television yes no 9 For what do youuse the Sinclair computer What other uses do you intend to make of it 10 Are you a member of a computer club yes no Is it at school or private 11 How long have you read Sinclair User Where do you obtain it What do you like about it What do you not like How could it be improved 12 What other computer magazines do you read Personal Computer World Computer and Video Games O Your Computer Practical Computing Microcomputer Printout Windfall Educational Computing Microdecision Which Micro O 2 Computing O Sinclair Programs Popular Computing Weekly Computer Today Any other State which SINCLAIRUSER July 1982 29 Plug in no desoldering Wi Space bar linked to space key Wi Full travel keys Six spare keys for your own use Wi Case available to hold keyboard and ZX 81 microcard W 16K RAM pack clamp supplied with case to eliminate white outs XN PROFESSIONAL 2 2 81 All you need Keyboard 28 95 W Case only 15 00 All prices inclusive of VAT postage and packing Please allow 21 days for delivery ah EI COMPUTER KEYBOARDS DIV DEAN ELECTRONICS LIMITED GlendalePark Fernbank Road Ascot Berkshire England Dial a leaflet 03447 5661 Telex 849242 ZX81 16K SOFTWARE
105. o scroll that element downwards Put the USR call in a loop and that should produce a moving runway effect Add the aircraft path by adding a POKE statement into the loop Allow the aircraft to be steered left and right by using inkey to modify the Figure 1 MAIN PROGRAM LOOP AR FAST LPRII 7i E a PRINT TAN EERND CLE HEHHHHHHHHHHHHHHHHHHHHHHHH 16534 PRINT AT 20 20 PB INT AT 20 58 GOTO ie 1 A USR T i8 asm Ue Ihave always had in the back of my mind the thought that scroll down would produce an excellent moving roadway or airfield effect we will build the game around that idea If you have other ideas for applications of the routine feel free to pursue them Here is my concept 62 POKE address Scroll down should create a plot of the previous positions of the aircraft Within the loop the mines on to the runway in varying positions Add the logic for a mine or verge collision That should send the program pointer outside the loop for comment and game re start Add program to advance the taxing speed of the aircraft as it proceeds Finally incorporate Program lines to signify a win create receding runway and a Figure 2 VDU PICTURE CREATED BY MAIN PROGRAM LOOP EEE jump outside this loop to comment on the win and allow game re start Now let us make a start with the main pro
106. om rex Tem rar owes FORM 10 cs CASSETTES en 37 1599 sess 55 _ Depr SUB eu 382 2 Drive 24 00 1 00 44 Shroton Street 8 e 1855052 london NWI 800 01 258 0400 Ee EZ E lelephone enguries welcome C25 Bp Cheque PO payable to Storkrose Lid ADORESS ERE Chore my Vit cord no Add min 1 50 or 10 P amp P a nee SIGNED similar in shape and style to ZX 81 and there are many simi larities Sinclair has kept the original keyboard to save space but has provided a rubber sheet with moulded keys on it which fits over the top The sheet is suspended over the flat keys which on the ZX Spectrum are bigger than the ZX 81 so that when a key is pressed it bends to give some feel to tho keyboard That and the fact that the keys repeat if held down for longer than one second even when using SHIFT makes the keyboard much easier to use The single keyword system has been retained and that saves memory as all the Basic words can be stored as one byte It also means that two SHIFT keys are required to reach all the functions one is called CAPS SHIFT and the other SYMBOL SHIFT They are at opposite ends of the keyboard and as they are often e D 5 ZX SPECTRUM is very Stephen Adams looks inside Sinclair s latest machine and finds it has a lot in common with t
107. omas Oakland CA94611 Harvard Group Bolton Road Harvard MA 01451 617 456 3967 user club MICHAEL ORWIN S ZX81 CASSETTES QUOTES Michael Orwin s 5 Cassette Two is very good value Itcontains 10stolid well designed games which work offer plenty of variety and choice and are fun From the ZX Software review in Your Computer May 82 issue had your Invaders React cassette delighted with this first cassette P Rubython London NW10 I have been intending to write to you for some days to say how much enjoy the games on Cassette One which you supplied me with earlier this month E H London SW4 previously bought your Cassette One and consider it to be good value for money Richard Ross Langley Managing Director Mine of Information Ltd was CASSETTE 1 eleven 1k programs machine code React Invaders Phantom aliens Maze of death Planet lander Bouncing letters Bug splat Basic Ching Mastermind Robots Basic Hangman PLUS Large screen versions of Invaders and Maze of Death Ready for when you get 16k Cassette One costs 3 80 CASSETTE2 Ten games in Basic for 16k ZX81 Cassette Two contains Reversi Awari Laser Bases Word Mastermind Rectangles Crash Roulette Pontoon Penny Shoot and Gun Command Cassette Two costs 5 CASSETTE3 8 programs for 16k ZX81 STARSHIP TROJAN Repair your Starship before
108. onitor I have seen various TVs and monitors connected to ZX 81s and with some the picture is poor and with others very good It does not seem to matter whether you use a video monitor or not My preference is for one of the Ferguson range of small black and white portables which I find give a very clear picture and which cope well with the interruptions in the signal caused by the FAST command I shall probably be besieged by letters advocating another make or model and so I repeat the ad try before you buy Geoffrey Ottley is going to the States for three years and he asks Will able to use my computer in the U S without further adaptation or will I need a new transformer Electricity is supplied in the U K at 240V 50 cycles per second whereas in the U S the supply is at SINCLAIRUSER July 1982 120V 60 cycles per second Hence a U S power supply will be needed with an output of 9V DC and rated at 1 2amps It will also be necessary to use a TV made for the British market because U K TVs display 50 frames per second whereas U S TVs display 60 frames per second The U S version of the ZX 81 is also rather better screened than the U K version so if your new neighbours complain of inter ference on their TV you will have to put your computer in an earthed metal box Perhaps it would be easier to buy a new ZX 81 on your arrival Now return to a topic which has aroused a g
109. ood deal of interest since I mentioned it two months ago Readers of the first issue of Sinclair User will remember that I described two Basic routines for transferring data from a program above RAMTOP loading a second pro gram from cassette and then transferring the data back to the being over written copy the program area above LOAD the data from tape in the usual way create some space in the program area and copy the program from above RAMTOP into the newly created space in the program area Obviously to create some data to LOAD into a program we must RUN a previous program to read in or calculate the data to be SAVE The earlier program could be deleted line by line but the process is rather laborious so use this technique instead First note the line number of the first line of the program Suppose it is line number 10 then find the effective length of the program by entering PRINT 16396 256 PEEK 16397 16513 Suppose the result is 1859 Then enter POKE 16511 1859 256 INT 1859 256 POKE 161512 INT 1959 256 10 or whatever was the first line number Do not attempt to LIST the variables area of the second program thus enabling two programs to speak to one another Les Auckland writes I would like to know how to SAVE and LOAD data only into a program held in core Can you assist There are two methods The first is quick and elegant and consists essentia
110. or another but PAUSE statements between words can be altered so that you can create your own from the words sup plied You are limited to the beginning of words however as the speech is stored only in complete words not sounds The speech pack costs 49 95 complete with ROM 1 and extra ROMs and so is completely com patible with the ZX 81 It costs 14 95 as a kit with outacase and 17 95 fully assembled with case The eight transistor driver box costs 9 95 and mother board 15 95 For orders of less than 20 add 50 pence for post Thurnell Electronics is at 95 Liverpool Road Cadishead Manchester M30 SBG Tel 061 775 4461 Printer interface CAPITAL COMPUTERS has produced the first motherboard with bank switching incorporated on board The expansion motherboard also sorts out the reflections of the ROM and RAM so that the full 56K left can be used It includes 5V regulator for a separate power supply an optional metal case and a range of plug in boards The boards contain 16K of extra memory full RS232 serial interface to drive printers Centronics parallel interface for printers complete with handshaking and 2716 ROM containing the driver routines All the expansion motherboard sockets are buffered so that the pulling out of cards should not crash the system The expansion motherboard costs 40 20 serial parallel interface board 45 95 16K RAM 33 93 and the metal c
111. r name and address on back of your cheque or postal order and send to D FRITSCH 6 Stanton Road Thelwall Warrington WA4 285 SINCLAIRUSER July 1982 I SOUND withZX 81 MAKE AMAZING SOUND EFFECTS WITH YOUR 2 81 25 95 THEZON X 81 The ZON B1 SOUND UNT is set contained ond especiaty designed tor use wit he DX just plugs Ro dsmonting or sobering power pack baltenes leads or other extras Monuo Volume oudspeoke Slondord 22 81 16K Rampock printer be plugged into TON X 8I Sound Unt wanout ate j 2 81 operation Huge range of possible sound Helicopters Space invaders Drums Planes Lasers Organs ha ging programme contol of y progrommes using a few piles ot ho need 1 81 PERSONAL BANKING SYSTEM with load save datafiles at double speed Load the program in t transactions 2X8 wil ferent datafile into the same 145 seconds enter items etc save datafile only onto cassette 45 seconds repeat Absolutely no need to save pr idin tafiles Very easy to use unlike other ba Require mum of 16k use much more no modification require Jemonstration at the next ZX Micro Fair The Personal Banking System also includes the following fe page detailed Bank Account dual displ jon otal ding any item prev fileo ed Single Multiple field
112. rior to anything I have written purchased written in Basic To you that may an obvious statement has become clear to me only on running them What I would like to do is to understand machine code of which I now understand the basic prin ciples and if possible to buy a program which could convert some of my many Basic programs into machine code Is that possible From your advertise ments there are one or two firms offering products which look as if they may answer the problem Control Technology Bug Byte to name two but they do not give sufficient detail for me to decide Iam told that what I am really looking for is a Com piler but I have not yet seen anything advertised as such Does one exist Can you recommend any good books or a contact with whom to discuss the matter Do readers have any a vice Meanwhile we have passed the query to Andrew Hewson our Helpline correspondent Letters should be kept as brief as possible and ad dressed to The Editor Sinclair User 30 31 Isl ington Green London N18BJ Space considera tions mean that it may be necessary to edit long let ters wu AS A FURTHER service to users of Sinclair computers Sinclair User is starting the Sinclair User Club Membership will cost 12 which will enable members to enjoy a large number of extra benefits They will include a bi monthly cassette based newsletter containing programs and a
113. ry hard to beat the computer at it ette 4 cost 5 12 Recorded on quality cassettes sent by first class post froi Michael Orwin 26 Brownlow Rd Willesden London NW10 9QL mail order only plea SINCLAIRUSER July 1982 AUTOMATIC ZX99 CONTROL The logical extension for the Sinclair 2 81 giving 59 95 data retrieval amp word processing The 2X99 Tape Control system a sophisticated extension to ASS the Sinclair 2X81 Microcomputer providing remarkable additional capabilities which allow both the beginner and expert access to professional computing system without the expected expense PROCESSING The 2X99 gives you full software control of up to four tape decks two for reading and two for writing allowing merging of data files to update and modify them This is achieved by using the remote sockets of the tape decks to control their motors as commanded by a program 3 PRINTER INTERFACE The ZX99 has a RS232C interface allowing you direct connection with any such serial printer using the industry standard ASCII character code you can now print on plain paper in upper and lower case and up to 132 characters per line The 2 99 contains own 2K ROM which acts as an extension 3X MANY SPECIAL FEATURES to the firmware already resident in your ZX81 S own ROM The ZX99 s ROM contains the tape operating system whose There are so many di
114. s greater than 10 and this kind of game can be a great help A program I have used flashes rows of squares for her to input the number figure two It was written specifically to help her understand the way in which numbers above 10 are recorded The same program of course can be adapted easily to give help with numbers above 20 Although the programs may appear limited they are still giving valuable practice in learning skills which if not understood fully can lead later to difficulty in comprehending for instance the value attached to carried 1 in 9 9 we carry one which is really The little ZX 81 with even a basic 1K memory can be used to teach the funda mentals of mathematics mathematics like myself who have children at school With the ZX available it would be a waste if it were not used constructively to further a child s education Initially most people probably write programs of the 6x5 variety They are useful but not especially interesting Try the program in figure one It is very simple the program prints out 10 rows of graphics squares with the number of squares printed at the end It can be 10 You may say that is well known but rest assured there are plenty of children who find the true value of a carried figure a total mystery Computer aided learning can give those children valuable lessons for they will know immediately if they are correct or incorrect In classes wh
115. sic market few people these days expect to be able to buy records in the same place as they buy their music systems Follow the route a little further and you begin talking about computer systems designed for home use One vision of the future suggested by W H Smith is that people start by buying some kind of simplekeyboard which in basic form could be used as a typewriter or calculator To this could be added various types of processor memory and printer to build a personal system to suit a variety of requirements Such thinking is perfectly logical and likely to happen since it sounds very like the way in which Sony developed the music market Before Sony split music centres into various parts most people listened to their music on record players built as one unit Such a thought prompts the question as to what the Japanese are doing about the home computer market It would be comforting to think that the lead which Sinclair Research and other British companies have in the field would be an advantage but such leads have been no insurance in the past SINCLAIRUSER July 1982 and are unlikely to be in the future That is especially true of the home computer market where changes can happen so quickly The British companies involved are also small One big push by a large Japanese conglomerate could be sufficient to push them on to the sidelines If the market is as big as estimated it would not even be necessary to launch
116. sive M R Irving 22 Wheatley Way Chalfont St Peter Bucks SL9 0JE SPECTRUM ZX81 BUSINESS GAMES AUTOCHEF As MD you must negotiate Tor lenses on mer prices ti ot Presso specty computer when ordering Each program makes use of HISTOGRAMS and BAR CHARTS and Se 18K 4 75 each or 8 00 for to C C S Tenor ese ZUCKMAN 16K The first ZX81 version of Puckman 5 95 inc PEP Send cheque or to D Looker DJL Software 9 Tweed Close Swindon Wits 2 81 1K Sinclair built with large keyboard in case plus 1 0 port and various programs 80 Bob Wilcock 41 Berwick Road Wood Green London N22 01 889 3571 QUALITY 2 81 SOFTWARE 20 Superb IK Games Inc Machine Code 2 75 16K Utilities in Machine Code 3 25 IK Utilities 2 25 16K Machine Code Editor for the Serious M C user 3 50 B RAO 12 Parkstone Close Bedford Beds Tel 0234 46248 2 81 COMPUTER 16K RAM QS prog Graphic Generator and mother Board 50 worth of software inc m c invaders Worth over 220 will sell for 160 Contact Banbury 54896 After 2 81 16K almost new DK 512 Pro grammed graphics 512 user definable KayDE keyboard Books basic machine code Tapes Games Invaders Chess etc Machine code Assembler Dis embiers Total value 250 selling 170 Dave Noonan 01 272 5674 At last 2X81 PHEONIX in 16K Expertly programmed and r
117. st be quoted when taking advantage of the offer which closes on July 31 Buffer Micro Shop is at 374A Streatham High Road London SW16 next to Streatham Station Each month Sinclair User will be listing free the growing number of ZX user groups throughout the world We hope the list will be comprehensive and if anyone is forming a new group or knows of one we have not included please let us know Britain Aylesbury ZX Computer Club Ken Knight 22 Mount Street Aylesbury 5181 or 630867 Meetings first Wednesday and third Thursday of the month Edinburgh ZX lub J Palmer 031 661 3183 Mitchell 031 334 8483 Meetings second Wednesday of the month at Claremont Hotel EZUG Educational ZX 80 81 Users Group Eric Deeson Highgate School Birmingham B12 9DS Glasgow ZX 80 81 Users Club lan Watt 107 Greenwood Road Clarkston Glasgow G76 7LW 041 638 1241 Meetings second and fourth monday of each month Hassocks ZX Micro User Club Sussex Paul King Hassocks 4330 Inverclyde 2 81 Users Club Robert Watt 9 St John s Road Gourock Renfrewshire 19 IPL Gourock 39967 Meetings Every other week on Monday at Greenock Society of the Deaf Kelly Street Greenock National ZX 80 and 2 81 Users Club 44 46 Earls Court Road London W8 6E North Hertfordshire Home Computer Club R Crutchfield 2 Durham Road Stevenage Meetings first Friday of the month at the Settlement Novells Road Le
118. stles to assist with editing and debugging machine code Campbell Systems 4K disassembler uses plenty of Basic and its machine code occupies my favourite 16514 onwards area of RAM It has a handy facility to step backwards and displays contents in hex with addresses and mnemonics in decimal You cannot dump direct 42 ZXAS assembler and occupies 4K from address 16514 It works entirely in hex and does not dump to the printer although you can circumvent that by disassembling 12 lines or so then calling 0869H which is the Sinclair ROM COPY subroutine Another disadvantage is that some of the mnemonics belong to the 8080 rather than the Z 80 e g LD A HL appears as LD A M It has a very large number of sophisticated monitor functions so 1 have included it among the monitors as well ZXDB costs 6 50 MicroGen Debug is also a disassembler with some monitor functions works entirely in hex and can be used with a printer Care has to be taken when transferring from Basic to Debug and back or the ZX 81 will crash I found the monitor display impressive although more detailed instructions would have been helpful The program lives above RAMTOP which it re sets automatically and costs 3 95 ACS Debug can be used in con junction with the ACS assembler and disassembler to provide a complete if rather expensive machine code writing package It stores above RAMTOP uses decimal numbers only and does not
119. t looks at dissassemblers and assemblers which are on the market 45 SOFTWARE SCENE We look at the new programs 47 HARDWARE WORLD More of the new items in the hardware market are 52 NEW BUSINESS Richard Altwasser and Steven Vickers two of the leading figures the design of the Spectrum have launched their own company special club gets under way we offer our second 56 HELPLINE Andrew Hewson and more of the problems which people find in using their Sinclair machines 59 MIND GAMES 62 MACHINE CODE The final part of the series by Mike Biddell programming 64 COMPETITION Following the success of our previous competitions we offer another printer and the Memopak 64K RAM pack as prizes this month 65 ADVERTISEMENT INDEX Your guide to the many items on offer in the pages of Sinclair User NEXT MONTH We assess Sinclair s new range of educational software More of your queries answered in Helpline ANOTHER GREAT OFFER TO SINCLAIR CLUB MEMBERS Philip Joy examines a game of chess which can fit into 1K achine code LEADERS IN COMPUTER GAMES FIRST CHOICE FOR 2 80 44 NR QS ASTEROIDS THRUST FIF JM and 4K QS SOUND BD m RAM 4 18 00 QS MOTHER BOARD BD amp 98 CONNECTOR QSCHRS BD programmable Special offers amp news 1 98 PRINTERFACE X ROM 428 00 2 Q8 HARMONY 4 50 e n connector CHRS bd The spe ARCTIC COM
120. tchworth North London Hobby Computer Club ZX users group meets at North London Polytechnic Holloway Road London 7 each Monday 6pm Nottingham Microcomputer Club ZX 80 81 users group E Basford 9 Holme Close The Pastures Woodborough Nottingham ton Computer Club Roger 23 Arundel Drive Orpington Kent Orpington 20281 SINCLAIRUSER July 1982 Post Offi Club Vernon Quaintain Head Post Office St Martin s d London lub C P Hazelton 26 Rilestone Place Bottesford lub 5 W Rabone 18 Castle Road Worle 8522 Weston super Mare 513068 t lays Il WSS Walsall 25467 to cover Walsall and West Bromwich area ZX BO ZXB1 Users Club PO Box 159 Kingston on Thames A postal club Overseas Belgium France Luxembourg Club ZX 80 81 Roger Betz Chemin du Moulin 38 B 1328 Ohain Belgium 322 6537 468 Denmark Danmarks National ZX 80 81 Klub DNZK Jens Larson Skovmosevej 6 4200 Slagelese post giro 1 46 24 66 East Netherlands Jonathon Meyer Van Spaen Straat 22 6524 Nijmegen 080 223411 Germany ZX 80 Club a postal club contact Thomas Jenczyk Hameln Postfach 65 D 3250 Hameln Germany Indonesia Jakarta ZX 80 81 Users Club 73 Cnoc Crionain Baile Atha Cliath 1 Spain Club Nacional de Usuarios del ZX 81 Joseph Oriol Tomas Avda de Madrid No 203 207 10 3a esc A Barcelona 14 Espana United States Bay Area ZX 80 User Group 2660 Las Ar
121. ted the following bestselling books and can supply from stock For the Beginner Getting Acquainted with your 2X81 by Tim Hartnell containing over 80 programs 34 Amazing Games for the 2 81 by Alistair Gourlay which shows you what you can do with only 1K of memory 49 Explosive Games for the ZX81 by Tim Hartnell which describes games listings for the memory sizes Coming Soon Learning to Use the ZX81 by Robin Bradbeer and Learning to Use the ZX Spectrum by Robin Bradbeer two new books in a new series designed to help the first time user both due August September 1982 The Personal Computer Book 2nd edition by Robin Bradbeer an introduction to the world of microcomputing which is generally regarded as the best available For the Enthusiast Mastering Machine Code on your ZX81 by Toni Baker will help you develop your programming skills to a point where you can really use machine code easily The Gateway Guide to the ZX81 and ZX80 by Mark Charlton is a doing book describing each function and statement in turn illustrates it in a demonstration routine or program and then combines it with previously discussed material The ZX81 Pocket Book by Trevor Toms covers the use of the ZX81 in detail and leads the reader into a clear understanding of programming A brand new book is 20 Simple Electronic Projects for the ZX81 by Stephen Adams which can really put your ZX81 to practical use in a number of interesting
122. ters are idiot proof Letting that go I set to work the next morning and I made an astonishing discovery it s easy you have to do to use a ZX 81 is fellow the instructions and believe me if I can follow the instructions anyone can To be honest am a wonderful human being with many precious gifts but a way with inanimate objects is not one of them So far as 1 am concerned sexual equality stops short of changing tyres or replacing washers and as forelectricity Lam like the man who thought there was cold electricity for refrigerators and coloured electricity for traffic lights Yet in no time at all I was able to use a sophisticated piece of equipment even to the extent of programming it to tell a silly joke Now I am just letting up before racing on to looping graphics and organisation of memory which sounds just the kind of thing I need Having said that however 1 can admit freely that it has not all been plain sailing In fact at first it seemed as if the whole self improvement plan would never get off the ground A 13 year old s bedroom is probably not the best place to conduct an important research project of this kind and my son s bedroom poss electrical wiring to fisherman s sweater continued on page 26 25 wa continued from page 25 You are ready to begin the manual said when a K appears in the bottom left hand corner of the screen but for that to happen I
123. tine can be stored there and will even re set the Basic variables so that a RETURN from the monitor will not crash the BASICare conversion BASICare has produced the Organic micro a system which makes in compatability between systems outofdate The idea is that every com puter should use the same connections to the RAM packs and ports but because each time a com puter manufacturer pro duces a new machine it changes the way it con nects that has not been possible previously Now BASICare will pro vide a personality module to convert the ZX 81 BBC computer or Apple in one standard connection so that any computer can grow from 16K RAM to more than 1MB of RAM The packs which use the bus will then be available to be used by any machine to provide printers ports Toolkit programs CMOS and dynamic modules The silver packs are connected mechanically as well as electrically to each other so there should be no chance of a faulty connection The basic Per sona module costs 30 42 inc VAT and postage BASICare Microsystem Ltd 5 Dryden Court Lon don 5 11 4NH Tel 01 735 6408 Metrimpex disc drive METRIMPEX of Hungary is introducing a revolu tionary new disc drive system to this country and atleastone manufacturer Macronics has opted for it The disc drive is very similar to an eight track tape recorder as the disc is stored in a hard plastic box which is opened only when the disc is ins
124. umbers are picked at random by the program and the player has a limited number of attempts in which to guess the numbers To guide the player the program marks each attempt by bulls and cows A bull denotes a correct number in the proper position in the sequence and a cow means that the number is correct but in the wrong place The game continues until the correct number is guessed or the player has had 15 attempts Press RUN for another number to be guessed Bulls and Cows was sent by G Gill of Westerham Kent 10 Dim N 4 20 1TO 4 30 LET 9 40 NEXT A 45 1704 50 1 04 60 IF C THEN 100 0 IF NIA THEN GOTO 20 100 NEXT 110 120 LET A 1 1000 N 2 100 N 3 10 130 PRINT ENTER YOUR GUESS 135 FOR F 1 TO 15 140 INPUT BS IF BS THEN GOTO 360 PRINT BS LETB 0 LETC 0 LET A STRIS A LET X AS ET C BS FOR S 1T04 FORD 1T04 IF CODE XS CODE CS THEN GOSUB 400 LET C TLS CS NEXT D LET C BS ET X TLS XS NEXT S IF 4 THEN 350 PRINT BULLS C COWS 270 NEXT F 280 PRINT I LL TELL YOU THAT IT WAS A 350 PRINT THAT S IT 360 STOP 400 IF S D THEN LET B 1 410 IF NOT S D THEN LET 1 420 RETURN Because of the large number of programs which have been sent to us we cannot acknowledge every thing which we receive If you have not heard from us within on
125. wledge however was much less Two years ago 1 did not even know what a ROM was he says Vickers 29 was also at Cam bridge gaining a degree in mathematics at King s College before doing his PhD at Leeds In 1980 after writing to number of computer companies including Sinclair for a job he joined Nine Tiles a software consultancy based near Cambridge which had written the ROM working memory for the ZX His first job was the adaptation of 4K ZX 80 ROM to make an 8K ROM for the ZX 81 He also wrote the manual for the ZX 81 and went on to write most of the ROM for the Spec trum as well as assisting with the that they found working for Sinclair very exciting viding you can cope with the pressure without having a heart attack The main difference they found between Sinclair Research and other companies in electronics was that deadlines were very real deadlines Vickers says There is a definition of a deadline that it is the date before which something should not be com pleted but that is not the case with Sinclair Development of the Spectrum was typical of the way in which Sinclair Research works A rough specifica tion was worked out with the main requirements including colour high resolution graphics and im proved tape storage interface That was set last September with final deadline of the Earl s Court Computer Show in April By that time the Spectrum had to be
126. ze Android Nim Play the Spectrum at the ancient game of Nim using creatures from outer space Biorhythms Plot the cycles of your Emotional Intellectual and Physical activity Some would say this is not a game at all Improve your mind Morse complete morse code training kit This program will take a complete beginner to RACE proficiency Maths Adjustable to various levels this program is an invaluable aid to anyone trying to improve their arithmeti Run your life more efficiently Home Accounts Keeping track of your finances with this easy to use program will enable you to see at a glance where the money goes and plan your spending more effectively Telephone Address Pad instant access to many pages of information Calendar Displays 3 month calendar past or future ideal for planning or tracing past events ORDER FORM Send Cheque or P O with order to Dept D Richard Francis Altwasser 22 Foxhollow Bar Hill Cambridge CB3 BEP Please send me Copies Cambridge Colour Collection Book only 6 95 each Copies Cambridge Colour Collection Book amp Cassette 9 90 each _ Address 17 1 fed pue Aym mou Ang se e WOJ 5 YH siempre 18 08XZ SHUO MD FULLER FD SYSTEM 39 95 Professional Keyboard amp Case for Sinclair ZX81 amp ZX Spectrum KEYBOARD LAYOUT The 2 81

Sinclair User - Retro Computer Resource

Contents

Download Pdf Manuals

Related Search

Related Contents