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July1982 LEARNING IS FUN WITH THE ZX-8I We look inside Spectrum The independent magazine for the independent user B.B.C.M I C R O A T O M ZX8 ZX8I VIC 4 0 id'o4 4se w A MAZE ADVENTURE k GAME FOR 1 0 2 , 4 s \ . 0 ) 1 ' 4 ZX8Ir a 0)('' • . . ce,603 o6 „co s( 9o i STARTREK! In which you The class' trek a c1051 the galaxy in search of , gammas to sop with your photon and c o m photon torpedoes You have 1011qecud pshort u t range e scanners to hekp you had rthem. Starbases to reluel your ship trick of course wallow witty g ,,mments a horn the ClOW m e , 0 DI AS ASSEMBLER ZXDB DEBUGGER • MAZOGS unlike i s any a other game you've seen on the M I . This is without doubt the best game available for this computer, b r a n and if you don't believe us, ask somebody who has d seen it or go down to your local computer shop and ask for n e a demonstration. MAZOGS is a maze adventure game with very fastw moving animated graphics. A large proportion of the g a is written in machine code to achieve the most program m e graphics you have ever seen on the ZX81 amazing You will be confronted by a large and complex Maze, f which contains somewhere within it a glittering and o fabulous Treasure. You not only have the problem of r finding the treasure and bringing it out of the maze, you must also face the guardians of the maze in the form of t ah force of fearful Mazogs. Even if you survive their attacks you could still starve to death if you get e hopelessly lost. Fortunately, there are various ways in I which you can get help on this dangerous mission. There are three levels of difficulty, and the game comes 6 complete with comprehensive instructions. The cassette K on which the game is supplied is of the highest quality, Z and loading is guaranteed. Mazogs is available from Bug-Byte and most good X computer shops at CIO. inclusive. 8 1 , • • .111mim ••••Mi. • • M ilE in• • • • • • •••1 1 MM ,• • • • • •••••• -••••••• • • . ••Mr• • • • • m • • • • • • • • • . 1 • M I • • .M IM E • • • • • • • • • - • • :101111M • - • = = n • • • • • • • • • 11=1=0.• • - • • • • • • • . • . . 1 M M •••••••• • • • • • • • • • .• • • • • • • N . • • • • , • . 1 • • • • • • • • • :E M E M • • • • • • • • • • • • • • • • • • • • MP . • • • • • • • • • • • • • • • • • • • d • • . ••=1 . . • ••••••••• • • • • • , • • • - • 100 The Albany, Old Hall Street, Liverpool L3 9EP & L I V E R P O O L L 3 3 A B . . . . C5 • E 00 ZXTK 'mower E6•00 CONS TE LLATION E 8 . 0 0 6 D MULTIFILE C17-50 P RO G RAM PACKS -I MAZOGS M O 5 M 1 - 8 (each)E 4 1 . 0 0 C 0 T D A A T M O S R VICMEN E 7 E 00 ANOTHER 'VIC IN THE WALL L 9 E7 00 V I CG AMMO N E 7 . & .0 0 ASTEROIDS E 7T 00 0 H 0 E B E Ell 50 SPACE WARP A El l 50 B.B.C. CHESS S E25 00 B.B.C. WIULTIFILE T E8 00 B. B. C. BACKGAMMON _ C7 00 B.B.C. GOLF E 6 . 5 0 T Ii 1 &MICRO * ts t v ATOM z INVADERS CHESS 747 FLI G HT SIMULATION GALAXIANS BREAKOUT C8 00 M O O F R U I T MACHI NE PINBALL E8-00 L ABY RI NT H C8 00 L U N A R LANDER E4.00 G O L F ALL PRICES INCLUDE POSTAGE — £4.00 _ £4.50 £7.00 £5.50 - E5 00 Nos e send ITI• I e 1 O R Please debit my. Access 5224 n Expiry date ▪ Barclaycard 4923 c I Nmne l Address Code o Dealers Discount Available s ACCESS, BARCLAYCARD ORDERS WELCOME ON 24M •e ANSAPHONE 051-227 254Z al mad to c• BUG-BYTE SOFTWARE, •h FREEPOST, (No stamp req.) . . o q u e / P 0 ZX81 B . B . C . MICRO A T O M SU•7•82 poge 6 ; a w l /4 5 S I NCLAI RV O Y ANCE We consider the future for retailing in the Sinclair market and its effect on suppliers. 6 S CHO O LS SPOT A teacher. Dave Sayers, wr i tes about his experiences using the ZX-81 i n his school. 9 LE TTE RS Mor e brickbats and bouquets from our readers, 1. 0 S I NCLAI R USER CLUB As our special club gets under way, we offer our second Star Bargain to club members. 1 4 S P E CTRUM REVI EW Stephens Adams looks inside the new Sinclair machine and likes what he sees. 1 9 N E W S W H Smi th's futur e pl ans, Z X shows ar ound t he countr y, a nd the sponsorship of the Cambridge half-marathon. 2 2 A M A T E U R RADI O Julian Moss looks at the uses of the ZX-8I in radio shacks, 2 5 N E W USERS Last 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, 2 8 RE ADE R SURVEY We ask you to tell us what you think of Sinclair User and the market for Sinclair products and spin-offs. 3 1 P RO G RAM PRI NTOUT Another eight pages of special programs, wi th one for the ZX-80, 4 1 P RO G RAM AI DS Phil Garrett looks at dissassemblers and assemblers which are on the market, 4 5 S O FTWARE SCENE We look at the new programs. 4 7 H A R D W A R E WO RLD Mor e of the ne w items i n the har dwar e mar ket a r e reviewed_ 5 2 N E W BUSINESS Richard Altwasser and Steven Vickers. two of the leading figures in the design of the Spectrum, have launched their own company. 5 6 HE LP LI NE Andr ew Hewson and more of the problems which people find in using t heir Sinc lair machines. 5 9 M I N D GAMES Philip Joy examines a game of chess which can fit into 1K. 6 2 M A C H I N E CODE The final par t of the series by Mi ke Bidden on machine code programming. 6 4 CO MP E TI TI O N Following the success of our previous competitions, w e offer another printer and the Memopak 64K RAM pack as prizes this month. • 6 5 ADV E RTI S E ME NT I NDEX Your guide to the many items on offer in the pages of Sinc lair User NEXT MON T H • We assess Sinclair's new range of educational software • More of your queries answered in Helpline • ANOTHER GREAT OFFER TO SINCLAIR CLUB MEMBERS SINCLAIR USER J ul y 1982 3 FIRST CHOICE FOR ZX: SUPPORT: LEADERS I N COMPUTER GAMES ZX-80 NX-81 Co Q8 D E F E N D E R . - DOWN T H R U S T - FIRE F irs t and o n ly fu ll screen display. So ftwa re to d rive QS SOUND BD. Mo vin g Pla n e ta ry surface. Up to 84 fast mo vin g ch a ra cte rs on screen a t once. On screen sco rin g Ten missile s at once. In cre a sin g a tta ck p a tte rn s. Requires 8K ROM, and 4 K min of RAM. £ 8 . 5 0 . QS AS TE RO I DS LEFT R I G H T T H R U S T F I R E So ftwa re to d rive QS SOUND BD Mu lt ip le missile s fi rin g in 8 d ire ctio n s. On screen scoring. I n cre a sin g n u mb e r of asteroids. Fu ll mo b ilit y of ship to all areas of the screen. Two asteroid sizes Bonus sh ip at 10,000 points. Requires 8K ROM, 4K min of RAM + SLOW fu n ctio n . * 5 . 6 0 . QS I NV ADE RS . LEFT R I G H T - FIRE 13x 7 INVADERS; Hig h score; 3 levels of play; RND saucers; Bonus base; Drive s Soi ind bd. & CHRS bd Re q u ire s 7K RAM, 8K ROM 4 *- 5 . 5 0 . Slow. QS 3 K R A N Bd. A n e xt re me ly re lia b le sta tic RAM Bd_ wh ich co mb in e s wit h the co mp u t e r's me mo ry to give 4K total. Plugs d ire ct in to the re a r p o rt on yo u r ZX Computer 18.00. QS S O I I ND BD. A p ro g ra mma b le sound effects board u sin g the AY-3-8910, 3 TONES; I NOISE; ENVELOPE SHAPER: + TWOS BIT I/O PORTS. E a sily p ro g ra mma b le f ro m BASIC, the A Y chip does mo st of the wo rk le a vin g yo u r co mp u te r free f o r o th e r things. Signal 0/P via 3.5 mrn Ja ck socket Ports 0 /P via a 18 p in LC. Socket. * 2 6 . 0 0 . QS CHRS BD./ A p ro g ra mma b le ch a ra cte r g e n e ra to r g ivin g - 1 2 8 SEPARATELY PROGRAMMABLE CHARACTERS. ON/OFF SWITCH. 1K ON BOARD RAM. Enables cre a tio n and d isp la y of your o wn ch a ra cte rs to screen o r p rin te r. Demo cassette of fast ma ch in e code operation ro u tin e s and lo we r case alphabet included. See below fo r ZX PRINTER listin g . * 2 6 . 0 0 . C I S - LOUER C R 5 E t _ i t , g h i j k t o n o p q r s t u v wx , it QS I I I - R E S BD. A Hi-re s g ra p h ics board g ivin g 258 1 9 2 PIXELS. 8K ON BD. RAM. SOFTWARE SELECT/ DESELECT. MI X E D TEXT AND GRAPHICS. 2K ON BOARD ROM. Resident fast ma ch in e code g ra p h ics so ftwa re (I n RUM) p ro vid e s the f o llo win g HI-RES Co mma n d s. - MOVE x, y, PLOT x, y; DRA W x, y, BOX x,y; UP; DOWN; LEFT; RIGHT; PRINT AS; SCROLL; BLACK; WHI TE CLEAR COPY See above f o r ZX P RINTE R listin g s u sin g COPY £ 8 5 . 0 0 . QS M O T H E R SCIARD BD. & QS CO NNE CTO R. A re lia b le e xp a n sio n system a llo win g a total o f any RAM pack p lu s two o th e r plug in boards to ty• in use at once. On board 5V re g u la t o r d rive s a ll external boards. Fitte d wit h t wo 23 way double sided edge connectors Co n n e cto r is 2 *2 3 way edge co n n s soldered back to back. E xp a n sio n can operate in two w a y s - ( 1 )COMPUTER • • CONNECTOR -- • An y QS add on bd, (b u t no e xtra RAM pack ). ( 2 ) COMPUTER - • CONNECTOR • • MOTHE R BD • • ANY RAM PACK ( 2 bds to fi t in mo t h e r bd M o t h e r board * 1 2 . 0 0 Connector * 4 . 0 0 . Special offer s & n e w s 4;18 P RI NTE RFA CE Con:le0.6 a. ZX L e r to an Ac orn At easy, to• uso ; r t gives S i Ilstings. m pc ommands l . : and Hi-Res screen dump. On board 2K ROM £ 2 8 . 0 0 ( A ) CIS H A R M O N Y A mac hine code programme for the QS sound board. gives you easy c ont rol of phasing, chorus. tempo, volume, pitch. Complete wi t h s ample programme to play the serenade f rom Mozart's Don Glovanni ZX81. 4K RAM £ 4 . 8 0 ( ARCTI C COIEPITITNG'S EX CHESS 11. * 4 5 . 0 0 . 3 The stro n g e st chess p ro g ra m wit h 7 levels of play ) Q STAL AND MONEY ORDERS TO: PO A L L S QUI M GI S KLI TA: 9 $ Please state 'Type of machine, Which ROM, Memory size, when ordering_ 9o PRODUCTS FULLY GUARANTED. sinclairvoyance Tempting gap in market and are unlikely to be in the future. That is especially true o f 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 b e necessary t o launch a particularly innovative product model. It would be pleasant to think it would be a British company which takes the plunge. I market for home computers, they should take note of the experience of W H Smith. The F company sells more magazines on computers than it A does women's magazines. T h e re a r e t h ree computer publications which sell more copies than N the most popular women's magazine. Y This explains why Smiths is expanding that side O of its retailing steadily. As the company puts it. most N of its sales are in "maturing markets", so the need to find new and dynamic lines is essential for its E qfuture. The growth potential i s phenomenal. I t i s uestimated that, despite sales of almost 500.000 eZX-81s, Sinclair Research has tapped only about 4 two percent o f the estimated home computer s 1 THERE IS possibly something to be said for the tmarket. Despite allowing for the fact that it is ponderous decision structures 1 of many of Britain's difficult to assess a market which did not exist two iyears ago, there is still an enormous hole in the major companies. With the 1 limitation of personal initiative and the promotion of company spirit, the omarket. 1 wish to leave and start a new business is severely n Smith's reaction in the medium term is to try to curtailed. m ecover the whole market for both hardware and Compare that to Clive 0 Sinclair's companies, past software. I n the long term, i t is thinking o f dspecialising on one sector, probably software. That and present, where initiative and freedom o f 0 tensures that the route future development will thought have been encouraged. It is one of the of being a small company that it is possible hfollow is much the same as that for the music benefits and i t has been used, b y Sinclair Research emarket — few people these days expect to be able to especially, to put new ideas into practice quickly. buy records in the same place as they buy their The freedom, however, is not total. In the end it is smusic systems. Clive Sinclair who takes the important decisions. i Follow the route a little further and you begin ztalking about computer systems designed for home Having tasted some easing of constraints, it can be very frustrating when there is still some limitation euse. One vision of the future, suggested by W H to action. Smith, is that people start by buying some kind of It was that frustration which led to the departure osimple keyboard which, in basic form, could be used f as a typewriter or calculator. To this could be of Richard Altwasser to join a growing band of former Sinclair colleagues from whom he now t added various types of processor, memory and faces some form of competition. hprinter, to build a personal system to suit a variety The people behind Acorn Computers and the of requirements. e Such thinking is perfectly logical and likely to Grundy Newbrain, which finally was launched last phappen, since it sounds very like the way in which month, all worked with Sinclair at some stage. oSony developed the music market. Before Sony split Altwasser and his partner, Steven Vickers, are keeping quiet about their plans but it is unlikely they smusic centres into various parts, most people will be straying far from the microcomputer field listened to their music on record players built as sone unit. Such a thought prompts the question as to they know so well. Whether their new company will be big enough to i what the Japanese a re doing about the home consider launching a new computer is open to bcomputer market. It would be comforting to think that the lead conjecture. Leaving that aside for the moment. l which Sinclair Research a n d other British there is still a large market in software and ecompanies have in the field would be an advantage hardware peripherals where they could compete but such leads have been no insurance in the past with their former employer. SINCLAIR USER J u l y 19/32 5 Simplicity is best learning pattern Dave Sayers relates how the ZX-81 has helped learning in his school. learning tool is often quoted T in papers and magazines, yet H of the published programs are most E games and adventures — and good P they are, too. Nonetheless, it is a pity that O more educational games a re not W published; the little ZX-8 I w i th even a basic 1K memory can be used E to many of the fundamentals R teach of ma th e ma ti cs o r , w i t h m o r e o memory, English. f The example programs included a th i s a rti cl e , therefore, a r e a l l in written m w i th i n I K . Th e reason i s simple. i To be good. a teaching game need not be complicated. Preferably c it sh o u l d te a c h o n l y o n e th i n g , r though th a t i s n o t to say th a t o mixtures o f approaches a r e n o t a desirable. s It should also, i f possible, have a 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, a re young people used to help to teach children who can co u n t w h o have d i ffi cu l ty i n associating those numbers with the written n u mb e r — f o r instance, seven. As you can see, I am starting a t the very fi rst basis of counting. My daughter h a s sta rte d learning t o write, o r record, numbers greater than 10, and this kind of game can be a great help. A program I have used flashes rows o f squares fo r her to input the number — fi gure two. It was written specifically to help her understand t h e w a y i n w h i c h numbers above 1 0 a r e recorded. The same program, o f course, can be adapted easily to give help with numbers above 20. Although t h e p r o g r a m s m a y appear limited, they are still giving valuable practice in learning skills which, i f not understood fully, can lead l a t e r t o d i f fi c u l t y i n comprehending, f o r instance, th e value attached to a carried 1 — in 9 + 9 we carry o n e " w h i c h 10. You may say that is well known ibut rest assured there are plenty of schildren who find the true value of a rcarried e figure a total mystery. a Computer-aided l learning can give those children valuable lessons, for l y they w i l l know immediately i f they are correct or incorrect. In classes 'The little ZX-81 w i t h even a basic 1K memory can be used to teach the fundamentals of mathematics mathematics' like myself who have children a t school. W i t h th e Z X available, i t would be a waste if it were not used constructively to fu rth e r a child's education. Initially m o s t people p ro b a b l y write p ro g ra ms o f t h e 6 x 5 = ? variety. Th e y a r e useful b u t n o t especially i n te re sti n g . T r y t h e program in figure one. It i s v e r y simple; th e program prints o u t 1 0 r o w s o f g ra p h i cs squares. w i t h t h e n u m b e r o f squares printed at the end. It can be 6 S I N where books are marked once a lesson, th e incorrectness o f w h a t they h a v e d o n e m a y b e c o m e apparent o n l y a t th e e n d o f th e lesson — or next day. Once w e have th e ch i l d underC L A standing counting to a certain total, speed practice becomes important in helping the child to rely less on physical cues of number and begins to depend on their internal memory of where they are in the count. The games s h o u l d s h o w v a r y i n g numbers o f shapes quickly on the screen, fo r w h i ch a running to ta l has to be kept b y th e child, to be entered at the end of the run. HISSING SID i s a n example o f such a program. Snakes appear on the screen, varying numbers each time. A to ta l i s i n p u t a t th e end, which is checked — figure three. There i s p l e n ty o f f u n w h i l e learning to count with this program, especially i f 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 i n both speed of display and numbers of snakes. For larger numbers alter line 2 0 and fo r less time between displays alter line 100. If you make it long enough a n d q u i ck enough i t becomes fa i r l y te sti n g , e ve n f o r adults. I wrote a similar program on the Pet at school and tried it on my own class, a s w e l l a s th e class o f a colleague. My class, b y n o w fa i r l y blase where m i c r o s a r e concerned — some of them prefer me to use the ZX their fathers o r brothers own one and they can crib my programs — enjoyed i t a g re a t deal . T h e colleague, w h o w a s interested i n I R USER J u l y 1982 what the computer could do, w a s surprised by the way in which some of the less-motivated children were captivated b y the game. She w a s particularly impressed w i t h t h e way i n which one boy, w h o w a s finding addition a tri a l , began to store the numbers in his head: then. staring into space for a minute or so, as h e totalled th e m, h e fi n a l l y delivered h i s answ er i n a v e r y positive way. Cone were the uncertainties he had about w ri tte n sums. when he would often be at the teacher's desk complaining t h a t h e c o u l d n o t understand. Replacing i t w a s th e desire to boat the computer, to have his answer before i t flashed on the screen. BRIDGES is a game in which the children attempt to build a bridge by answ eri ng a d d i t i o n q u e s ti o n s correctly. Each correct answer puts another sp a n o n th e bridge. A s before, t h e y a r e a d d i n g b l o cks, figuret le 20 30 40 50 80 70 FOR 1 = 1 T O 1 0 FOR J = 1 T O I P R I N T "Mt - ; NEXT J PRI NT I PRI NT NEXT I Figure2. 10 R . O , 30 * 4 01 L E T C L 5 FOR R = f I N T I R N E I = 1 A 0P )R4I .N1T0 ) TO A 50 NE X T I 55 P RI NT 60 I NP UT 6 70 I F A = 6 T H E N G O TO eke P R I N T -. ; A RO O RN IG= 1 T O 1 0 0 W RF O 100 NE X T I 1 ,1 0 O L S 1 I2 e G OT T O 1 0 Fi gurWel A SS C L 5 10 L E T c = 0 20 LE T A = ( I N T ( R N D * 5 ) + 1 ) 30 FO R I = 1 T O A 40 L E T 8 = ( I N T ( R N D 4 6 ) + 1 ) SO L E T O = C + 6 60 FO R J = 1 T O 5 70 P R I N T " ( 3 5 P A C E 5 ) - W w W W W W M 1 " 30 P R I N T 96 0 N E X T J 100 FO R K = 1 T O 7 0 110 NE X T K 115 OLS 120 NE X T I 130 P R I N T “ HO W MANY 5 N A K E 5 ? " 140 I N P U T D 150 I F D = C T H E N GOTO 160 P R I N T “ THE RE WE RE ” ; C ; " 5 N A KES SINCLAIRUSER J ul y 1982 170 180 190 FO R I = 1 NE X T I GOTO rather than numbers — figure five. When the game is run, blocks, in two rows, appear on the screen. I f they are added correctly. a span is added to the bridge. I f they are not added correctly, there is no penalty; the p ro b l e m resumes a g a i n a n d again until it is solved correctly. That is important, as there is no worry that the child will feel he or she h a s fa i l e d o n t h e fi r s t f e w attempts i f the bridge is not nearing completion. Those w i t h 1 6 o r m o r e K o f memory might like to improve this program. Fo r instance, th e bridge may fi ll the whole screen and every time there is an incorrect answer a man might w a l k along th e bridge and fall off, to land in a boat, from where he is returned to the bridge to climb and tr y again. Whether you use these ideas or not, it is important to pay careful attention to what you want yo u r program t o teach a n d never to take fo r granted the idea that children understand the logic of mathematics. T O 1 0 0 Figure 4, Change these lines 130 for u I t o 150 140 next u DO not forget to delete line 150. Fi gur e5• 6 7 10 20 30 40 50 60 70 80 90 LET S = 0 PRI NT PRI NT PRI NT FOR I = 1 T O 1 0 PRINT Alisclei spRcEs)aligNEXT I LET A = ( I N T ( R N D * 9 ) + 1 ) LET 8 = ( I N T ( R N D 4 9 ) + 1 ) FOR I = 1 T O A PRI NT A T 1 5 , I ; " 1 " NEXT I FOR I = 1 T O Et _too P R I N T R T 1 7 , I ; " 1 " NEXT I 120 LET 5=54-1 130 I NPUT D 1'35 I F D > R 4 . 8 T H E N L E T 5 = 140 I F D= A+ 8 THE N P R I N T A 1; "al - A 150 I F 5 = 1 0 THE N GOTO 3 0 0 1.6e1 P5 R+ I N T A T 1 5 , 1 ; 170 P - RI NT A T 1 7 , 1 " ( 1 2 S P 160 I F 5 = 1 0 A N D D=A4-5 T H E C 1 2 400 190 5I F PD =AA +C5 ET H5E N) G O T O 4 0 200 G O TO 6 0 "P R I N T 400 Y O U B U I L T A 5 - 1 T 3 ACE S ) " N GOTO 7 Explore the Excellence of your7JE81 With ITIEVIOTECHAdd-Ons riemoTun ADD-011 1 plus 5UST 2 4 3 0 • Switching inverse video on and off gives flashing characters/numerals etc • Video pages can be • Access to video page is superimposed by s i m i l a r to plot and unplot software switching c o m m a n d s in BASIC The pack comes in an elegant aluminium case, anodised black and Styled to fit onto the back of the ZX81. allowing more add-ons IMemopak RAM, Sinclair printer. etc) to be connected without a further power supply It contains a 2K EPROM monitor, holding a full range of graphics subroutines which can be called by the BASIC USA function or by machine code For your future needs, well allow you El ° against your purchase of our 64K model if: you return your 16K pack within 3 months of receipt: you supply evidence of purchase. your 16K model is received by us undamaged and unopened. - • We reserve rhe right to rmect 10, Obscountog purposes Jrtrrl, whet , Oa ., e b e e r , e t , t h e f o p e n e d o f d a m a g e d , n a n y w a y • Fully programmable high resolution (192 x 248 pixels). • Video page is both memory and but mapped. • Video page can be located anywhere in the RAM • The number ol video pages is limited only by your RAM N N s i z e each page occupies about 6.5K RAM) and pages can overlap. • Instant inverse video. i n Memopak 16K Memory Extension MEIWTECII EIDD-011 It is a fact that the ZX81 has revolutionised home computing and coupled with the new Memopak 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 ZX81'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 ZX81 giving firm, wobble-free connections 12600 plus UST Memopak 64K Memory Extension mvisancts 1100-0t1 I 6/3 plus 10 URT The 64K Memopah is a pack which extends ill memory Di Itie ZXB1 by a further 56K, an together with the ZX81 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), BRE AKDO WN OF MEMORY AREAS 0 - 8 K S i n c l a i r ROM 8-16K T h i s section of memory switches in or Out in 4K blocks to leave space lor memory mapping. holds its contents during cassette loads, allows communication between programmes, and can be used to run assembly language 'outines. 18-32K • Thi s area can be used for BASIC programmes and assembly anguage routines. 32-64K 3 2 K of RAM memory for BASI C variables and large arrays With the Memopak 64K extension the ZX81 is transformed into a powerful computer. suitable for business, leisure and educational use, at a fraction of the cost of comparable 1systems. MEMOPAK RAM Price N o Total Please send me I CENTRONICS_f E29 90 16K RAM (a E26.00 * E3 90 VAT P cheques payable to t E79.00 l 64K RAM (Ft E68.69 - E10.31 V AT I t e Please Debit my HAG 0 M _ E59.80 1 a AccessBarclaycard• 1 E account number Packaging & Postage (a) E2 00 per unit A complete range of ZX81 p e n p h e r a l s s E52. M TO TAL ENC Centr oni cs Interface & Softwar e Drivers e 00 O • Reese delete wh•cheve Digitising Tablet R S 2 3 2 Interface m 4 , d o e s r h o t T We regret we are as yet unable to accept a SIGNATURE D A T E a p p l y E orders or enquiries concerning the above E k NAME A D D R E S S 7 C products, but well let you know as soon e T E L E P H O N E 8 H as they become available. 0 CR Bre nton L O A C Boyd 1962 L • • • m • t We want to be sure you are satisfied with your Memopak — so we offerV a 1 4 A d Memotech Limited, 3 Collins Street, Oxford 0X4 1XL, England Tel: Oxford (0865) 722102 Telex: 837220 Orchid G T . Coming S o o n I • W RES GRAPHICS 1 I . /I T I r s cl of.CC -1 o30 , c091U.,00 1S e 4 0 l, 0n1 aco ' j l t c a should be and so i t pulls t the connections apart. The t answer i s simple — j u st ° remove the case. ' Giles Colborne, „ Galampton. , Devon. , , Memory wobbles MUCH has been written on the subject o f R AM pack wobble, l i ttl e o f i t giving any sound advice as to how it may be prevented. I feel that th e th r e e solutions which I have found are the best to date. The Sinclair RAM would be as good as any other, except fo r the fa ct that i t does not appear to be very eager t o s t a y o n t h e computer and will jump off when any key i s touched hard enough. If you have E 2 to spare. you can buy a ribbon cable and solder one end to the RAM and plug the other to the edge connector o f the PCB. T h a t m e a n s t h a t when yo u h i t a k e y to o hard, a l l th a t happens i s that t h e r i b b o n c a b l e absorbs the shock. The second method i s simpler and cheaper and just as effective. A l l th a t you do is to take a piece of Blutack and place it on the RAM. a b o v e t h e e d g e connector. When you plug in the RAM it is held to the computer by the Blutack. The th i r d w a y t o stop RAM w o b b l e , h o w e ve r, does n o t c o n c e r n t h e Sinclair RAM but the Byg Byte RAM. Initially there is nothing wrong w i th the RAM and it is a very good alternative to the Sinclair RAM but the case is about three ti me s t h e si ze i t SINCLAIR USER J uly 1982 I know that you can obtain a fi l t e r u n i t w h i c h goes b e tw e e n t h e w a l l socket a n d th e computer plug which w i l l suppress the spikes b u t I d o n o t know which type would be best for my ZX-81. Could you advise me as to which method of solving the p ro b l e m y o u w o u l d suggest a n d w h e r e t h e goods can be obtained? Paul Coker. London SEUL •Can readers help? W e are se n d i n g i t t o o u r I WA S ve ry interested i n Helpline co rre sp o n d e n t, your article on the ZX-81 Andrew Hewson, to see i f 16K R A M pack, i n p a rt- he knows the answer. i cu l a r t h e p a r t w h i c h stated th a t th e computer can suffer from whiteouts I AM very grateful for the due to the fl uctuations i n April issue of Sinclair User but i t does not tell me how the mains supply. I have found th a t to be to make my p ri n te r work. The books which are sold an a n n o y i n g p r o b l e m , especially when loading a do n o t te l l you, either. I t program which takes more would b e much b e tte r i f than four minutes to run. you t o l d people h o w a I have heard that is due 7.-X-81 works, otherwise I shall have to sell mine and to the voltage spikes in the g ri d o v e r - l o a d i n g t h e buy an Apple. I w ri te and w ri te again memory and re-setting it to to Sinclair, w i th o u t even the input mode, leaving the an acknowledgment. mode K o n m y scre e n , Maurice Nadin, which has happened tome. Surrey. I know th a t th i s i s the •iNe h o p e l a t e r issues problem, as the same tape and equipment will record have been more help and perfectly during the times that yo u h a ve n o t been when the grid system is not compelled t o t a k e t h e being used a g re a t deal; drastic step o f buying an i.e.. b e fo re 8 .3 0 am a n d Apple. between 2 pm and 4.30 pm. It is not always convenient or possible to work on my computer a t those times; CONGRATULATIONS o n mostly I like to work in the an excellent magazine. I t evenings, which can be the is j u s t w h a t Z X u s e r s worst ti m e f o r th e p r o - wanted. I a m n o t a p ro blem. grammer and prior to buy- Stopping whiteouts Apple threat Changing to machine code 9 ing my 'IA I did not have a clue. Through practice, I am rapidly picking-up the techniques a n d fi n d th e hobby ve ry interesting. I find, having bought some programs w r i t t e n i n machine code, t h a t th e y are eminently superior to anything I have written, or purchased, w r i t t e n i n Basic. To you, that may be an obvious statement but it has become cl e a r t o me only on running them. What I would like to do is to understand machine code — o f w h i ch I n o w understand the basic principles — and, i f possible, to b u y a program w h i ch could convert some o f my many Basic programs into machine c o d e . I s t h a t possible? From y o u r a d ve rti se ments there are one or two fi rms o ffe r i n g p ro d u cts which look as i f they may answer t h e p ro b l e m — Control Technology, Bu g Byte, to name two - but they do not give sufficient detail for me to decide. I am told that what I am really looking for is a Compiler b u t I have n o t y e t seen anything advertised as such. Does one exist? Can you recommend a n y good books o r a co n ta ct with whom to discuss the matter? D R Wall, Manchester. •Do readers have any advice? Meanwhile, we have passed t h e q u e r y t o Andrew Hewson, o u r Helpline correspondent. •L e tte rs should be kept as brief as possible and addressed t o T h e E d i to r . Sinclair U se r, 30-31 I s l ington G r e e n , L o n d o n N18131. Space considerations mean th a t i t may be necessary to edit long letters. 1 AS A FURTHER service to users of Sinclair computers, Sinclair User is starting the Sinclair User Club. Membership will cost E12, which will enable members to enjoy a large number of extra benefits. They will include a bi-monthly cassette-based newsletter containing programs and answering 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 El 2 Name Address Send your coupons to Sinclair User Club, EGG Publications, 30-31 Islington Green, London Ni 813j. Cheques should be made payable to Sinclair User Club. 10 S I N C L A I R USER J ul y 1982 Sinclair user club E3 off the Dean Electronics keyboard 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 E35 but we are able to offer the keyboard through Buffer Micro Shop for only E32. In addition, the case, which usually costs E14.50, is offered at El 3.50. Membership cards must be shown or numbers must 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 Z X Co mp u t e r Cl u b ; K e n Knight . 2 2 Mo u n t St reet Aylesbury (5181 o r 630867). Meetings: fi rs t Wednes day and t hird Thursday of the month. Edinburgh ZX Users Cl ub: J. Palmer (031 661 3183) or K Mitchell (031 3 3 4 8483), Meet ings : s ec ond Wednes day of t he mont h a t Claremont Hotel. EZUG-Educational ZX-80/81 Users' Group: Eric Deeson. Hi ghgate School. Birmingham 1312 9DS. Glasgow ZX-80/81 Us ers ' Club: I an Wat t , 107 Greenwood Road. Clarkston. Glasgow G76 7 LW (041 638 1241). Meetings: second and Fourth monday of each month. Hassocks ZX Micro User Club, Sussex: Paul King (Hassocks 4530). Inverclyde ZX-81 Us ers ' Club: Robert Wat t . 9 St. John's Road, Gourock, Renf rews hire, P A 1 9 1 P L (Gouroc k 39967). Meet ings : Every other week on Monday at Greenock Society of the Deaf, Kelly Street, Greenock. Nat ional ZX-80 and ZXI I I Us ers ' Club: 44-46 Earls Court Road, London W8 6EJ. North Her tfor dshi r e Hom e Computer Cl ub: R Cr utchfiel d. 2 Durham Road, Stevenage: Meetings: fi rst Friday of the month at the Settlement, Nevells Road, Let c hwort h. North London Hobby Computer Cl ub: ZX users' gr oup meets at Nort h London Poly t ec hnic , Ho l l o wa y Road, L o n d o n N 7 e a c h Monday, 6prn. Nottingham Mi cr ocomputer Cl ub: ZX-80181 user s' gr oup, G E Basford. 9 Holme Close. The Pastures, Woodborough, Not t ingham. Orpingt on Co mp u t e r Cl u b : Ro g e r Py alt , 2 3 A r u n d e l Dr i v e , Orpington, Kent. (Orpingt on 20281). SINCLAIR USER l u i y 1982 1 Post O f f l e Us ers ' Club: Vernon Quaint ain, Head Post Offi ce, St Mart in' s le Grand, London, E d . Sc unt horpe ZX Club: C P Hazellon, 26 Rilestone Place, Bottesford, Scunthorpe; (0724 63466). W o r k Co mp u t e r Club: S W Rabone. 1 8 Cas t le Road. W o r k . Wes t on-s uper-Mare 11S22 9 1 W (Wes t on-s uper-Mare 513068). Meetings: Woods prings Inn, Work ), on alt ernat e Mondays. ZX Ai d: Conr ad Roe. 25 Cher r y Tr ee Avenue. Wal sal l WS5 41,11 (Wals all 25467) to cover Wals all and West Bromwic h area, ZX-80/ ZX8I Us ers ' Cl u b : P O Box 159, Kings t on-on-Thames . A postal club. Overseas Belgium, Franc e Lux embourg: Club ZX-80/81, Roger Betz. Chemin du Moulin 38, B-1328 Ohain, Belgium: (322 8537 468). Denmark : Danmark s Nat ional ZX-80/81 Klub (DNZK), Jens Larson, Skovmosevej 6.4200 Slagelese. post giro 1 48 24 66. East Netherlands: Jonathon Meyer. Van Spaen Street 22.6524 H.N. Nijmegen; (080 223411). Germany: ZX - 8 0 Cl ub. a postal cl ub: contact Thomas lenczyk. Hameln, Postfach 65 13-3250 Hameln. Germany. Indonesia: Jakarta ZX-80/81 Users' Club. 73 Cnoc Crionain. Haile Atha, Cliat h 1_ Spain: Club Nac ional de Us uarios del ZX-81. los eph-Oriol Tomas. Avda. de Madrid. No 203 207, 10, 3a esc. A Barc elona-14 Espana. Uni ted States: Bay Ar ea ZX-80 User Gr oup, 2660 Las Aromas, Oak land CA94611. — Harv ard Group. Bolt on Road, Harv ard MA 01451; (617 456 3967), 1 MICHAEL ORWIN S ZX81 CASSETTES CASSETTE 2 QUOTES "Michael Orwin's 1E5Cassette Two is very good value. Ten games in Basic fo r 16k ZX81 It contains 10 stolid well designed games which work, offer Cassette Two contains Reversi, Awari, Laser Bases, Word plenty of variety and choice, and are fun." Mastermind, Rectangles, Crash, Roulette, Pontoon, From the ZX Software review in Penny Shoot and Gun Command. Your Computer, May '82 issue. Cassette Two costs £5. "I had yo u r Invaders/ React cassette . . . I w a s delighted with this first cassette." P. Rubython, London NW10 CASSETTE 3 ZX81 "I have been intending to write to you for some days 8 programs for 16k to say how much I enjoy the games on 'Cassette One' STARSHIP TROJAN which you supplied me with earlier this month." Repair y o u r S ta r s h i p b e fo r e E.H., London SW4 disaster strikes. Hazards include asphyxiation, radiation, escaped . . . . I previously bought your Cassette One and biological specimens and plunging consider it to be good value for money!" into a Supernova. Richard Ross-Langley STARTREK This version o f th e w e l l kn o w n space Managing Director Mine of Information Ltd. 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. CASSETTE 1 KALABRIASZ World's silliest card game, full of pointless (eleven lk programs) complicated rules. CUBE Rubik Cube simulator, w i th l o ts o f functions machine code: React, Invaders, Phantom aliens, Maze of death, Planet including 'Backstep'. SECRET MESSAGES This message coding program is lander, Bouncing letters, Bug splat. very txlp oexi jf. Basic: I Ching, Mastermind, Robots, Basic Hangman. PLUS MARTIAN CRICKET A simple b u t addictive game Large screen versions o f Invaders and Maze o f Death, (totally unlike Earth cricket) in machine code. The speed is variable, and its top speed is very fast. Ready for when you get 16k. Cassette 3 costs £5. Cassette One costs £3.80 CASSETTE 4 7 games for 16k 2X131 INVADERS ZX-SCRAMBLE (machine code) with 3 stages. G U N F I G H T code) ( m a c h i n e code) Bomb and shoot your way through the fortified caves. ( m a c h i n e ar --. . ,-/ . 41 T71 _.• 4 . ; : , • auk Am Am A m a 7, p l7 , R l r i O U N lo A I , . OM M k a '.e • i , ii .. i %MO • • o n . • - -1 1 • 1 . 1 • ' ' i i r ,- I I • t i r • id % M t q • • M A • O T O % 1 1 . •U 0 • a GALAXY INVADERS (machine code) L I F E (machine code) of the well known game. Fleets of swooping and diving alien craft to fight o ff. A ZX81 version (Basic) SNAKEBITE (machine code) 3 D TIC Eat the snake before it eats you. Variable speed. P l a y e d on a 4 x 4 x 4 board, this is a game for the (very b r a i n , it is very hard to beat the computer at it. T A Cfast at top speed). TOE 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). Cassette 4 cost £5. Recorded on quality cassettes, sent by first class post, from: Michael Orwin, 26 Brownlow Rd., Willesden, London NW10 9Qt. (mail order only please) 12 SI NCLAI R USER l u ly 1982 A U TO M AT I C TAPE CONTROL ZX99 The logical extension f o r 0 9 • 9 5 the Sinclair Z X 8 I giving data retrieval & word processing plus P & P The ZX99 Tape Control system is a sophisticated extension to. the Sinclair ZX81 Microcomputer, providing remarkable additional capabilities, which allow both the beginner and expert access to a professional computing system without the expected expense. * D A T A PROCESSING The ZX99 gives you fu ll software co n tro l o f up to fo u r tape decks (two for reading and t wo fo r writin g ) a llo win g merging of data files to update and mo d if y them. Th is is achieved b y using the remote sockets o f the tape decks to control th e ir mo to rs as commanded by a program. * P R I N T E R INTERFACE The ZX99 has a RS232C interface allowing yo u direct connection with any such serial p rin te r using the in d u stry standard ASCII ch a ra cte r code (yo u can n o w p rin t on plain paper in upper and lo we r case and u p to 132 characters per line.) * M A N Y SPECIAL FEATURES There are so many d iffe re n t features that it is d if fi cu lt to list them all: For example: AUTOMATIC TAPE TO TAPE COPY: Y o u can co p y any data file regardless o f yo u r me mo ry capacity (a C90 has approx 200K bytes on it ) as it is loaded through the Sinclair block by block. TAPE BLOCK SKIP wit h o u t destroying the contents o f memory. DIAGNOSTIC INFORMATION to assist in achieving the best recording settings. * T A P E DRIVES We supply (and guarantee its co mp a ta b ility) a Tape Drive that works with yo u r computer. * C O M P U T E R C A SSETTES We supply quality (screw assembled) co mp u te r cassettes. Please enquire fo r any n o t shown: The ZX 9 9 contains its own 2 K RO M wh ich acts as an extension to the fi rmwa re already resident in yo u r ZX8 1 'S own ROM. The ZX99's RO M contains the tape operating system, whose functions are accessed via Basic USR fu n ctio n calls. Each function has an e n try address which mu st be quoted after the USR ke ywo rd . A ll o f the functions can be used in program statements, o r in imme d ia te commands (i.e. both statements with line numbers and commands wit h o u t them). There is an extension board on the rear to plug in yo u r RA M pack (larger than 1 6 K if required). The u n it is supplied with one special cassette lead, mo re are available at E l each (see below). COMPREHENSIVE USER M A N U A L INCLUDED I N PR IC E * Z X 9 9 SOFTWARE* We n o w have available " E d it o r-9 9 " , a q u a lity wo rd processing program in clu d in g mail-merge, supplied on cassette fo r E9.95. Also, fo llo win g soon will be: • Stock Co n tro l • Ord e r Processing • Sales Ledger * De b to rs Ledger • Business Accounts • T x Acco u n tin g • • =• COMPUTER CASSETTES QTY PRICE TOTAL QTY P R i a ITEM , • P&P T O T A L See left CS 35p CASSETTES CIO 37p 1)(99 C12 38p E312 Ta pe Drme C15 39p E DI TO R-9 9 C20 4Ip CASSETTE LEAD C25 43p C30 44p Add min El 50 or 10%P & P • 59.95 2-95 24. 00 1-00 995 •50 1. 00 -10 Cheque/PO payable to Stotkrose Lid p r i z . 1 C h ORDER FORM To dato-oHettet Dept ,4 4 S hr otor , S pree!. LonciOn NWI ouG Te l : 01. 258 0409 S Telephone enqxnnes welcome U aNAME i ADDRESS Stephen Adams looks inside Sinclair's latest machine and finds it has a lot in common with the ZX-81 Taking the lid off the Spectrum similar in shape and style to the T ZX-81 and there are many simiHlarities. S inc la ir h a s k e p t t h e Eoriginal keyboard to save space but Zhas provided a rubber sheet with Xmoulded keys on it which fits over Sthe top. The sheet is suspended over Pthe fl a t keys — which on the ZX ESpectrum are bigger than the ZX-81 so that when a key is pressed it Cbends t o giv e some fe e l t o t he Tkeyboard. R That and the fact that the keys Urepeat if held down for longer than Mone second, even when using SHIFT, i makes the keyboard much easier to suse. The single keyword system has been r e ta ine d a n d t h a t saves v memory, as all the Basic words can ebe stored as one byte. It also means r that two SHIFT keys are required to yreach 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 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 t h e a ddition t o t h e Basic commands of IN and OUT. They give an instruction IN A(c) 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 ZX-81. T h e Spectrum ha s a 28-way double-sided edge connector of the same style as the ZX-81, with the keyway on pin 5 . Tha t makes any input-output device compatible w i t h t he ZX-8 1 b u t a ny memory-mapped devices w o u l d have to be rearranged. The edge connector also has a number of new signals an it which are not explainedi in the manual, plus a video output and colour outputs for VDUs, All t h e voltages us e d o n t h e Spectrum a r e a ls o brought out, namely + 5V, -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 pa c k seems t o ha v e been transplanted on to the Spectrum. The obvious additions t o t h e circuitry are the PAL colour mixer later it will cost E60. which I think is under the metal can which contains the video modulator a nd the fact expensive. There would be no difficulty in tha t t w o c r y s t a l - c o n t r o l l e d adding extra ports to the memory oscillators a r e used, one f or the map, as on the ZX-81, above 32K — ULA, whic h controls t he screen on the basic version b u t for two among other things, and the other things. There is no RAM CS line, so for the colour mixer. The 14m1-Iz that the extra RAM can be turned- clock for the ULA is also used to off if required on the edge connector drive t h e Z-BOA microprocessor and t he edge connector address after it has been reduced to 3.5rn1-lz, lines have been moved to the outer That i s 0.25mHz faster tha n the edges so that it is incompatible with ZX-81. The Z-80A has also been '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 a s you a r e constantly swapping hands. For instance, RUBOUT and the cursor movements use CAPS SHIFT and + -* a r e SYMBOL SHIFT. I t 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 wit h one ha nd while the other searches f or the appropriate key. 14 SI NCLAI R USER l u i y 1982 freed of the job of putting-out the altered so easily, as the dots are screen — by the ULA — and so no stored in peculiar order, so you have longer r e quir e s t h e commands to use the graphics commands — FAST or SLOW, as it works at top which can define all the dots on the speed all the time except when BEEP 22 line b y 3 2 character screen available t o t he user — o r t he or PAUSE is used. PAUSE and BEEP both cause the SCREEN command. There can be only two colours for Z-80A to stop for a time determined each character square, one for the by the programmer and so it will do nothing else while those commands foreground (INK) and one for the are being done. BEEP commands background (PAPER), but they can should be kept short in a program be any one of eight colours. They can for that reason; 0,01 seconds is a also be inverted at a rate of one per good speed to PRINT AT and BEEP at second continuously, s qua r e b y the same time. square ( FLA S H ) o r h a v e t w o intensities of colour (BRIGHT). As f o r p r o g r a m m i n g t h e The screen takes up 6.912 bytes of Spectrum. it can be considered as an extension of the ZX-81 Basic. The the 16K memory a nd the system PAPER, IN K , BRIGHT and FLASH variables take up another 738 bytes. commands f o r e a c h c ha r a c te r The rest of the memory is not free for square are stored in a memory map the user to use as 11 other areas above the dots for each character. float above location 23733 and can They are all stored in one byte per expand and contract as required by character and can be read by the the Spectrum. Basic word ATTR and altered either The program and variables are sandwiched in the middle of those, by Basic commands or POKEs. so REM statements cannot be used The dot screen is a different matter, however. a nd cannot b e for machine code. There is an area, SINCLAIR USER h a y 1982 however, whic h 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. The r e a r e m a n y t a p e arrangements which can be made with the Spectrum. The program. strings or machine code can all be SAVEd, LOA D e d a n d V E R IFI' d separately. T h e v a r ia ble s a n d screen can also be stored on tape but cannot be VER Ir id. As each is SAVEd, a messsage to start the tape recorder will appear and wait for you to press a key. That is a very good e x a m p l e o f t h e u s e r friendliness o f t he machine a nd most o f the errors appear wit h 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 w a s surprised w i t h t h e difference in speed between it and the ZX-81. I have been able to deal with only a fe w subjects. There is so much more to learn about the Spectrum from t h e manual t h a t i t 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. W i t h disc, networking facilities and RS232 interface it is a great improvement on the ZX-81 but it cannot replace it. as the price of E1 29.95 will still be a little daunting to those who want to try a computer for the first time 15 BE I THE ZX81 COMPANION THE INSIDE STORY Bob Maunder If you have a Sinclair ZX8 1 and want to use it to its full potential then, as the experts have all agreed, this is the book for you. It contains detailed guidelines and documented programs in the areas of gaming, information retrieval and education, as well as a unique listing of the 8K ROM for mac hine code applications. 'Far and away the best o n c e again Linsac has produced the • book for the serious end of the market' - Your Computer. November 1981 7heZ)(81 Companion is a most professional product w i t h many good illustrative programs, tips and warnings' -Educati on Equipment, October 1981. machine is brilliantly successful t hought f ul l y written, detailed B and illustrated with meaningful programs . . . To conclude - the o book is definitely an outstandingly useful second step for the ZX8 1 b user - EducetionalZ)(80/81 Users' Group Newsletter, September M 1981. a u n d Send your cheque for E7•95 (Includes UK p&p) to: e r ' s a Price ET 95 t t e m p Music 1K £2.93 t Music 2 f3.95 t Nightmare Pa rk - 14K E4.95 o High Res Graphics 16K E3.95 s Space Invaders 1 1K £4.95 Space Invaders 6 3k £5.95 h Breakout m i nK lk E3.95 o 16K E4,95 Dragon Maze Planetoids 16k £3.95 w Scroll/ m 1-16k E2.95 Rolling Rile e Lite 16k 0.95 CI.7.17.71 , Startrek 16K £4.95 a Mission at SC1DK RAM p a c kn* * 16K E S 95 the Deep assem bled, t e st e d a n d cai se d Fruit Machine (NO W ONLY f26.00 Inc nP & P i and Pontoon 16k E2 95 lAilow 21 days delivery) 16K E3 95 Space Rescue g Warrior f4 95 f 30 & X e + Connect Four 16k L 5 g5 u l lk £5.95 Assembly u 3K E11.95 Assembly 13 t i t ing Hex L e r f p . 111 f1.00 s e * whatsoever s N • • • • MO M o o h f a S.A.E. t or c atalogue t r All programs s upplied on h d cassette wit h ins truc tions w e Send remit t anc e wit h order Ll N SAC IANSAC S ) m",:da:sz:z i, T t i , n5t h 5oErrnn ( , I S B N0 9 0 7 2 1 1 0 1 1 1 NMI n o o L l i eiN a (Cheque, P.O. Card Nai to;r IMP4P4P1 •- k30 .4 q u alit y g am es an d sp eci al t ech n iq u es the w id est ran g e avai l ab l e f ro m o n e su p p lier ! 16 e n a n Dept S 1•1 d Spiers Close 26 rknow le h Sishuil e West Midlands 693 9E5 a t e a SI NCLAI R USER n a 111101%11113% J ul y 1982 D037Ert ZX Spectrum f ro m J.K. G R E V E S O F T W A R E TI I C N C I I C C I N I C C i r s T C f ) C T I f O r t f Li nt I CC I I % I 11_111 U LI IC.1\111 IUI I J U I WI 'With o u t question the fi nest machine code games available t oday " J . N . RO WL A ND Product Manager f or W.11 S MI TH. GAM EETAPE 1 toe I X ° r e l y ELI E 10 Gornto I n cl AST ER O I D S. U F O C O D E BO M BER GUILLOTINE. KALEIDESCOPE, e tc PROSAMLY TH E BEET VALU E I lt TAPE AVAI LABLEWe've Pone e l k ga me s whrch some o f o u r competitors required le k to do' AL m i c z n • CO O • GAM EST APE 2 low I SK o n l y EL M •STANFIGHTER Supe rb machine code Spa ce Ba ttle S e t agenst • ba ckground o f twinkling sta rs w i t h stunning explosions - if you can hit the enemy' PYRAMOD Can you move the Pyrarnod? M ake a mistake and it mil colt/4-31A Thinkers game AornsT The ulemate Graphic Demoners e d. 13 Chrections, 1 0 Memories, SAVE. COPY. RUBOUT C LS, etc GAM EETAPE 3 tot I l k o n l y WS •CATACOM BE A M ulti-Le ve r Gra phics Adve nture E a ch one ca n contain u p to 9 ROOtna, 8 Passages. 7 Monsters, Food. Gold. Tra ps. Phantoms, a n Exit I t o the ne st le ve l!, and there's an infinite number of levels NOTE T h e a NOT one of the neCessanly limite d te xt Adventures as sold elsewhere "An ekcatient eddocrive game w h y' ,fork kC kOa M kP U e Te E pR V I D E O GAM ES y e w 1 1 0 7 1 , 4 5 GAMIEST 0 P r API 4 for ISR o n l y ELI E i .3 0 M O N ST ER PAAZ E l i w Ga me t o T o p A l l Othe rs Unbeleewthle Graphics! Ca n you find youi wa y through the M a te The EXIT a there somewhere, but then so is a T REX, and it s a fte r YOU ' All in 3 0 t h e T REX ye ll a ctua lly ru n towards you in full persnoctivell. yO u la - ke the before' "3ye 0 MnONSTER E W EM t AZE s isetheebe st n game I have seen t o r the ZX8t C O M P U T E R Et VI D Ec GAM ES a n y t h i n g 'kW I had to c , , the ZX81.. the n J K. Gre ye 's 3 0 M ONSTER M AZE would be the one without doubtZ G IN T U P M O C X o 0 O se t u $ 1 S for INK o n l y tun aGAM n ESTAPE y .3 D DEFENDER T h e Ultima te Spa ce Ga me . Supe r la st p Machine r o Code g 3 0 version of the Arcade favourite. You have r to ps owo your w riorre planet Pram the marauding Alien S oacechsh nThis . a a ll in 3 0 , your viewscreen shows you the vie w Out r A Yaw fighters cockpit wridow. The backdrop moves when you turn. or fly up or clown le flight direchonsi. lust e s rt you t were really flying it! But then YOU ARE! The Enemy Saucers t will actually r zoomn towards you in 3 0 . a nd shoot you if you le t theme Your displa y oincludes p Score. Shield Strength Aratude. Prolorrahr, Forward Rader and your viewemen, which shows your rotating h o n e cannel. ba ckdrop o f Sta rs. M eteors, Explosions, r e Plasma Blasts yo u r Photon Beams u p to 4 Enemy SaUCC-t3 end a t rourse its a ll in sfull 3D s DA ASH NI T a t the Z X M icrof as Uncut of the othe r softwa re INMOMIEM wa nte d • , SMU Ccopy),Pa owns not to ba rolasacti W , GAM EETAPE I Porn( o n l y E lle C e •BREAM OUT Supe r Fa st Full Scre e n Doole y Ga me Y o u r m all Imne layounte with an added Ne st. Se e how much Money i you ca n win and wa tch the pounds convert t o Dollars A l l l in Machine Code for Fast Action with 3 Speeds, 2 Ba t Sire s , and three angles of rebound' The best BR EAKOU T around anti et this pr ic e y ou c an' t g o y o u n g ' t h e e s p G AME S M A R K E D • I N C L . M A C H I N E C O D E . e Prices include V A T and U. K. P. & P. b I Add t appropriate Postage on Foreign Orders), Cheoues/P.O.s to e t t e s o f CREDI T CA RD SALES: Phone. 01 - 839 - 4465 (9 a.m. • 7 P.m.) J.K. G R E V E S O F T W A R E Dept.SV, 16 Park St., Bath, Avon BA1 2 TE. FO R I N S T A N T D E S P A TC H If you wa fe r to see W o e buying, otjr range of GA M E S TA P E E 20 Programs E6.95 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 e xp e ri e n ce re q u i re d . Si mp l y e n te r th e programs from the book or load them from tape (E2.95 extra) and run. Amazing e f f e c t s . A l l p ro g ra ms a r e f u l l y animated using hi-res graphics, colour and sound wherever possible. Entirely original. None o f these programs has ever been published before. Proven Quality. The author already has 30,000 satisfied purchasers of his book of ZX81 programs. Hours o f entertainment • Lunar Landing. C o n tr o l the angle of descent and jet thrust to steer the lunar module to a safe landing on the moons surface. • Maze. F i n d your way out from the centre of a random maze. • Android N i m . P l a y th e Spectrum a t th e ancient game of Nim using creatures from outerspace. • Biorhythms, P l o t t h e c y c l e s o f y o u r Emotional, Intellectual a n d Physical activity. Some would say this is not a game at all. Improve your mind • Morse. A complete morse-code training kit. This program will take a complete beginner to R.A.E. proficiency. • Ma th s. Ad j u sta b l e t o various levels, th i s program is an invaluable aid to anyone trying to improve their arithmetic. Run your life more efficiently • H o me A c c o u n ts . Ke e p i n g tra ck o f yo u r finances w i t h t h i s easy-to-use program w i l l enable you to see at a glance where the money goes and plan your spending more effectively. • Telephone Address Pad. Ins t a nt access to many pages of information. • Calendar. D i sp l a ys a 3 month calendar past or future, ideal f o r planning o r tracing p a st events. ORDER FORM: Send Cheque or P.O. wit h order to:— Dept. D., Richard Francis Altwasser, 22 Fox hollow, Bar Hill, Cambridge CB3 BEP Please send me 0 Copies Cambridge Colour Collection Book only E6.95 each. • Copies Cambridge Colour Collection Book El Cassette E9. 90 each Name: ate sthcitect by the foiwiing stores BUFFER M I CROSHOP 3 7 4 A Streatham High Rd., LUry.1011 S GEORGES 8 9 Park St., Bristol, Avon. WI B MICROSTYLE 2 9 Belvedere, Lanadown Rd , Ba th. Avon PASCROWARE 131 meiTor,Ro•d. Leicester SCREEN SCENE 1 4 4 St. Georges Rd Che lte nha m. Otos lols H . SM I TH Computer Branches. Address ZE D X TR A S S chool Lane K ins on B our ne m outh D or s e t TRADE 8, EXPORT ENQUI RI ES WELCOME SINCLAIR USER l u i y 1982 1 7 M UM 1 u t — 0 iSFPA !WOO 0i 1)4' 0 1 1. ! M0i iti I3s- h . 1 tL nq i5-=l i -t-Ec i ; t P 4 *1* t i g A I D S J 1i t . 0 2 e 0cr 0 2 v • * N l i L I P ! c0 ; T i t it 2; E t z ; 4 -1k * t' g c i 2 1 — -3 2i q L . 0 /Oct 2 te 1 y 2 E .A lEg 21 = c " a = 3 T1V2§1 tot 18 , t;% 0 1?1 a C M - = c o_ z U 2 P N , „ zuift50 EE 4= a3 z E " ? 3 t 1 ( . z TA 0 o 4 tA:21Ohlis-A 1 ' E T ol 1 U 5_ 5 0 w g ro s rl c i , g o u 4 1 1 , f7 m t,— . 5 § L 8 t et -8u S E F 0 c z 0A%r ›- c bElO -• t e J4LA Z5F • 8 1 • • Z T ,1 -7 . .1t , 11,q: I § v n ° 1 I ;i111. W ,i'di t0Etiihi 8 i4 : 1 1 A1, 1 0 r1 u laill:1114 i1111ifidi s t1 g 18 tt Ei l T lr 1A 1 i M pti z aqi e 1 ii di 1 !11 ip ithlbi 1 1 Ill 1 lifYib• 4titillilli 1 ffimittizi 141. 1 SENCLAIR USER J ul y 19112 • FULLER FD SYSTEM E39.95 I Professional Keyboard & Case for Sinclair ZX81 & ZX Spectrum The ZX81 fits inside The t o u g h A B S injec t ion m oul ded plastic case measures 8" x 14" x 2 and h o o k s u p t o y o u r Z X pri nt ed 1 circuit board in minutes. No technical / 2" know how or s oldering is required. The ZX16K Memory Module will fix inside t h e c a s e , u s i n g t h e n e w Adaptor B o a r d a t E 9. 75 o r t h e Motherboard. By removing the ZX PSU from its case this c an also be fi xed inside. We will carry out the installation work free of charge i f required. KEYBOARD LAYOUT: 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 money back guarantee. 6 o p e r a t i o n s . T h e u n i t i MOTHERBOARD: INSTALLATIONs We also manufacture a mother board which allows Simply unscrewf the ZX printed circuit board from its case and screw it into the FD Case. u expansion t o t h e Z X m em ory a n d 1/ 0 facilities WITHIN the case, as well as our power supply unit l and reset switch. l y A D Code Price t Amount O b t 39.95 u Fuller F D System 42 Keyboard & case y 15.95 i FD System Motherboard 29.95 l FD 16K. Memory Module 78. t FD 64K. Memory Module 9 5 t 12.95 0 FD PSU 9 Volts at 2 amp. 3 0 e FD Shipping and Handling 2 . 5 0 co c s CPt-I/p O M a i l to FULLER MICRO SYSTEMS, o •ti) 0 T h te ZX Centre, Sweeting Street. Liverpool 2. England, U.K. k00 S A Ee f or more details — Enquiries : Tel 051-236 6109 Id to c ) ) o o , a --„; Address N n City/State/Zip a d m e c o "Best explanation I've seem this is a must" * / 4 4 "Best independent softwq 1 for the Z X 8 1 " k package ; ., ,o 2 , Syntax • Magaz ine sad: i t s the best explanation of Machine Langut MACHINE LANGUAGE MADE SIMPLE F O R for m Machine Language beginners I've seen. Its friervolly style is painless ..reading and simple analogies help make this k:inguage clear. This introduction is a must:' youn Available as a quality paperback, 160 pages. 19.75 including post. pack .and VAT. si * E t UNDERSTANDING YOUR D M ROM by Ian Logan Dr. Ian Logan was the 1981 winner of the Rosetta Stone Awar d*, given to the best independent product. software pac k age or application for the Sinclair ZX80 or ZX81, for his perceptive insights into the way the ZX81 ROM operates This book explains ZX80 Machine Language in terms of the ZX81 ROM, grving numerous examples of routines from the ROM, and explains the structure and organisation of the ROM. including routines from the ROM you c an use yourself A . special section explains how to use machine c ode routines in your own BASIC programs Availatpie as a quality paperback. 164 pages, 9.75 including post, pock and VAT ZX8I ROM DISASSEMBIN PARTS A St • Dr. Logan is also the author of these two titles (see abov e) which are on invaluable source of information for the serious ZX81 Machine Language programmer. Part A lists all locations and subroutines in the ROM from 0 0 0 0 H to 01-54H ancl covers all the operating functions of the ROM ex c ept the fl oating point calculator. Part B lists all locations from 0F55H to 1DFFH and covers all the routines involved In the 'evaluation of an expression' a n d a detailed explanation of the 'fl oating point calculator' Co-authored by Dr. Frank O'Hara Part A 3 0 pages, 17.80 including post. pack and VAT Pat 9.84 pages. 18.80 including post, pack and VAT. Other titles available: Not only 3 0 programs (or litto Sinclair DUN: IS Not only ov er 3 0 programs , f rom a r c a d e games t o t he fi nal c hallenging Draught s play ing program. whic h al fit int o t he unex panded 1K Sinclair ZX81 but also not es on h o w t hes e programs we r e writ t en and special tips! Great v aiuel 120 pages, 1:775 Compl• to Sinclair INS1 Basic Courso The Co mp l e t e Basic Cours e is a 2 4 0 p a g e in-dept h c omprehens iv e text f or c o mp l e t e beginners a n d ex perienc ed pr ogr ammer s O v e r 1 0 0 programs a n d ex amples illustrate t he use a n d p o s s t i e s of t he Sinclair .1X81 This is on inv aluable ref erenc e guide for 'all ZX81 owners 256 pages . 0 8 3 0 Speckil Discount for ordering more than I titie If you order more than one title at a time, you get a discount of 80p per additional title If you order 2 books, deduc t 80p from the total; order 3 books and deduc t 1160. order 4 books and deduc t .124011 Orders to M e itxxime House Publishers131 I mbrium riOCKi Gre e nwich London SEX) Commpondence t o Gtostwi C o t t a g e . Sta tion g o a d , C he ddinglon. Le ighton e u/ ra rd BEDS 1U1 ?NA The Comote le Sticlor 1X151 BASIC Course BUSC Course Programs on Cassette Not Only 3 0 Programs/Sincias 1X81 IX M a ohire Language Programming M ode Simpie 1X81110M DisassemON Pa t A IXSIPCArt DisasternOto Part B tirdesstaricing Your Diel ROM Address Remittance enclosed I - P o s t c o d e Less Special Quantity Discoord EILIO WO 1.11K) E810 £9.75 Smith adds to micro range W H SMITH expects to be selling another computer by the end of the year. It is talking t o a number o f manufacturers a b o u t stocking the ir micros t o add to the ZX-81 which it began s e l l i n g l a s t 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 in the company's move into the h o m e c o m p u t e r market, which it sees as a major growth area. I t is ZX fairs spread to North already e x t e nding t h e num be r o f b r a n c h e s John Rowland, ma rke t development manager of W H Smith selling com puter goods and increasing the amount will be selling more than 100 lines of software. of s e l l i n g s p a c e , particularly in the larger Rowland says that in the branches. next few years W H Smith "We s e ll 5 0 line s o f would probably like to sell s oftwa r e a n d a r e about three machines with increasing t h a t a l l t h e a full range of hardware time. W e think w e a r e add-ons a n d s oftwa r e . ready to take the next step After that, he thinks the in o f f e r i n g a n e w market will probably go machine," Rowland says. the s a m e w a y a s t h e He added that when the record market, with some new product is launched it retailers concentrating on is hoped it will be accom- hardware a nd others on panied by a full range of software. Of t h e h a r d w a r e software. He expects that by next year the company market, h e s a y s t h a t Smith's entry will depend on manufacturers agreeing t o a s t a n d a r d interface. Without that it would not be possible t o generate sufficient sales to make it worthwhile. The follow a course through retailer is looking for highthe city's historic streets, volume sales, which is why The company, which is it c hos e t o e n t e r t h e based in Cambridge, sees market with the ZX-81. Rowland a d d e d t h a t the sponsorship of the race as part of supporting the Smiths is also looking a t cultural life in the city. It the possibility of becoming will also be sponsoring a a software publisher. The concert in Kings College. company already receives Cambridge as part of the many suggestions e a c h festival. week. Clive to run in half-marathon CLIVE SINCLAIR's energy seems to be endless. Not only is he able to mastermind one of the most successful c om pute r c om 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 he is to take part i n a half-marathon being organised as part of the 1 9 8 2 C a m b r i d g e Festival. Sinclair Research i s sponsoring the event with E5,000 and it is expected that 2,000 competitors will be taking part, including a number o f t o p - c l a s s runners. The race will be held on Sunday. July 18 a nd will SINCLAIR USER l u l y 1982 THE FIRST exhibition for ZX users to be held in Birmingham is attracting a great d e a l o f interest, despite its clash of dates with t he Personal Computer World show in London. The organiser. Eric Deeson. says that about 40 of the major companies in the m a r k e t a r e t a k ing space. The idea for Microscene Brum 8 2 , o n Saturday. September 1 1 , resulted from t he successful Z X Microfairs in London. "Many people said how inconvenient it was having to g o t o London s o w e thought we would try for a regional s how," Deeson says. H e is hoping to attract people from all over the Midlands and further north. Meanwhile a ge ne r a l microcomputer f a i r i s being held at Manchester on July 2 4 a nd 2 5 . I t is being held in conjunction with t h e University o f Manchester Ins titute o f Science and Technology at Sackville S t r e e t . M a n chester and is aimed at the e duc a tion a n d s m a l l business markets. Brain power wins ZX-81s TWENTY-THREE regional winners i n t his y e a r ' s Mensa Superbrain competition have been awarded ZX-81s. T h e a wa r ds were prompted by Clive Sinclair's inv olv e m e nt with t h e British Me nge Society, o f whic h h e i s 2 chairman. The competition is a n annual event and is set to be a test o f intelligence rather than memory, as in Mastermind and Brain of Britain. It is usually run in conjunction w i t h provincial ne ws pa pe r s o n a 1 regional basis, w i t h t he regional w i n n e r s p r o ceeding to the final. This year, for the first time, extra sections were organised through the independent local radio network, whic h p r o v i d e d fi v e regional winners. 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. old as radio itself. Ever since A M a r c oni s e n t t h e fi r s t M transmission across the Atlantic, A radio amateurs ha v e be e n e x Tperimenting with new modes of communication and, in the process, makE ing friends across the world. U R Many of today's radio amateurs use commercially-made equipment R but there is still a good deal of exA perimenting, in aerial design for exDample, and at very high frequencies. ILike any technical hobby, there are O many uses for a computer and the i7-X-81 has found its way into many sradio shacks. Its uses fall primarily into thr e e areas — information a storage and retrieval, mathematical hand scientific programs, and realotime on-the-air applications. b b y a s Programs in the first category are fairly straightforward. O n e e x ample is an index of radio stations contacted o r heard. Every r a dio amateur has his own call-sign, in which t h e fi r s t t w o o r t h r e e characters denote the country — for example, the G4 in the call-sign G4ILO indicates England. Since a typical ham may make thousands of contacts in a year, it is impossible to remember every one. By storing on the computer each call-sign, along with the operator's name, town, the date and perhaps other details, it is possible to recall immediately whe t he r o r n o t a s ta tion h a s b e e n c o n t a c t e d previously and to see the details of the contact. The data can be sorted into call- sign order, to see how many countries have been contacted — useful since many amateurs compete for certificates which are awarded for contacts wit h, f o r example, 1 0 0 countries. Another use for the computer is to compile a n inde x o f te c hnic a l articles i n r a dio a nd electronics magazines. Mos t r a dio amateurs, like home computer enthusiasts, accumulate magazines devoted t o their hobby. I t i s frustrating t o search issue after issue looking for an article you remembered reading a few months ago. If a description of each article is stored in the computer, together with the name of the publication, its issue date and the page number, it is possible to have a program whic h w i l l search t h e descriptions and produce a list of all the articles relating to a particular topic. Typically, m or e t ha n 3 0 0 references can be stored on a 16K ZX - Another facet of amateur radio is contests. O n s om e we e k e nds . 13 E l ma teu r operators from all over the 1 .world try to make as many contacts as possible in a given period, usually 24 hours. The scoring varies from contest t o contest but usually is based on the number of contacts made a nd the number of country 22 SINCLAIR USER l u l y 1982 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 c a ll-s ign a n d dis pla y a message if a station has been contacted previously in the contest. On the technical side, there is a vast number of uses for the DC-81. Two examples a r e aerial design, when the computer can be used to work-out the dimensions of an aerial for a particular frequency, and even to calculate its theoretical performance; and the design of electronic circuits. American magazines publish programs o f tha t nature frequently. Those programs are usually written for the most popular home computers i n t he U .S., s uc h a s t he IRS-80, but it is fairly straightforward to convert them to run on the ZX-81, the main differences being that the IRS-80 does not require the word LET in a n assignment statement a nd tha t i t 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 pic k u p am ateur transmissions on one frequency and re-transmit them on another, allowing communication over distances which might otherwise not be possible. 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 satellite is 'visible' from a location and in which direction to point the aerials. SNCLA IR USER l u i y 1982 One p r o b l e m w h i c h r a d i o amateurs soon encounter when they put a computer in the shack is interference. The DC-81 radiates a good deal of radio noise, which is picked up by the receiver and can easily oblite r a te we a k signals. Usually it is necessary to screen the case carefully, using aluminium foil, and to filter the lead from the power supply. T h e R A M pack must b e screened as well. The reverse of that situation can also oc c ur , whe n R F f r om t h e transmitter interferes w i t h t h e operation of the computer. This is not usually a problem wit h t he DC-81, however, although the television used for the display can be affected sometimes. Once those problems have been overcome, the computer can be used on-the-air t o s e nd a n d 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 hardware. us ing t he 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 difficulty is that. in SLOW mode, the Z.X-81 spends about 15 out of every 20 milliseconds displaying a picture on the TV and that interferes with the generation or reception of the code. Thus programs for Morse or R r r y usually are written to run in FAST mode. A M o r s e de c ode r h a s be e n 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 pressed. N ois e a n d interference w i l l upset the decoding and the signal should go ideally through a narrowband filter, so that only the wanted signal is fed into the Z.X-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 radioteletype signals'. Morse c ode a n d radio-teletype signals, and even to control the station. Many of the new amateur radio transceivers use a microprocessor to control the various functions such as frequency a nd mode, a nd the various control lines a r e brought out to a socket at the back. Using a suitable interface, i t would be possible to program the ZX-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 limes of the day, or to monitor the strength o f pa r t ic ula r dis t a nt stations. It would even be possible to 2 and is stored in the first REM statement of the program. The easiest way to enter the routine is to type-in a REM with 24 characters in it 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 0 if no signal is present at the input port, or a positive number if one is present. There is a Sinclair Amateur Radio Users' Group in the U.K. Anyone interested s hould c ont a c t P a u l Newman, G4INP 3 Red House Lane, Leiston, Suffolk, IP16 4lZ, enclosing a stamped addressed envelope for details. 3 NEED MORE MEMORY FOR YOUR ME81..2 t _ 1 * Pr etor i us * 1 6 k B a n k A c c ount c a s s e tte by Futuresoft + E 3 T r a d e i n o n o u r 16k unit for a 6 4 k unit i f r e tur ne d within 6 m onths : 16K-f19.95 we at F R E E S y s t e m s have 64K-E47.95 c om m i s s i one d a l eadi ng e l e c t r oni c s c om pa ny t o desi gn f o r u s a l o w c o s t V E R Y h i g h q u a l i t y m e m o r y m o d u l e s p e c i fi c a l l y f o r t h e Z X E l l . I t c s n be u s e d i n a n y e x p a n s i o n s y s t e m e n d s i m p l y p l u g s i n t o t h e b e c k o f y o u r Z X 0 1 a n d a s s u c h i s ful l y c o m p a t i b l e w i t h t h e ZXI El l p r i n t e r . T h e 1 6 k m o d u l e w i l l g i v e y o u 1 6 t i m e s m o r e m e m o r y a n d i s fi n i s h e d i n A B S pl asti c. T h e i r i s a l s o a 6 4 k v e r s i o n w h i c h w i l l p r o v i d e y o u w i t h a p u r e 6 4 k o f pr ogr a m P O W E R . Thi s a m a z i ng a c hi e v e m e nt i s pa c k e d i nt o e x a c t l y t he s a m e casi ng as t h e 1 6 k m odul e a n d l o o k s i denti cal . N o t e : t h e s e u n i t s a r e B R I T I S H m a d e a n d shoul d n o t b e connector s. 14 confused Nothi ng m or e t o days m one y ba c k Your or de r P L E A S E i s w i t h qual i ty i m por t s t h a t ov e r he a t a n d ha v e p a y ! P r i c e s i ncl ude V A T + F R E E p o s t a g e ( o v e r s e e s o f f e r i f r i o t s a t i s fi e d + 8 m o n t h s w a r r a n t y . r eci eved S E N D l ow a t 8 . 3 0 a n d i s de s pa t c he d Guanti t M E : Da t e Na m e b y 1 2 . 3 0 Price 16k 19.95 6 4 k 47.96 t h e sl oppy o r d e r s .a.E2) s a m e day. Tot a l Aci dr eSS P a y m e nt to: P R E T O R I U S S Y S T E M S M a i l t o ; B . C . M . B O X 7 9 7 7 . W C 1 N . LON D ON . EN GLA N D . 24 SI NCLAI R USER J u l y 1982 Nicole Segre finds that, despite her reservations, understanding the ZX-81 is only a matter of time. Discovering the adult charms of the ZIC-81 last month about the upheavals I COMPLAINED a t some length caused in the household by my son's pur c ha s e o f o n e s m a ll, seemingly innocuous e le c tr onic machine c a lle d a ZX - 8 1 . W h a t 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 whic h le ft m e feeling decidedly passé. I have determined to remedy all that. It is important. in my view, not only to keep up with the times but to teach a ll those uppity youngsters not to under-estimate their mothers. Accordingly, I waited for a short pause between a game of Star Bash and a game of Clank! and obtained my son's permission to tinker with his Sinclair dur ing those hours SINCLAIR USER h i l y 1982 when attending t o his education kept him away from more pressing matters. " Is there anything I must not do?" I enquired anxiously. "No, it's all right," he said. "Computers are idiot-proof." Letting that go. I set to work the next m or ning a n d I m a de a n astonishing discovery — it's easy. All 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, I am a wonderful human being with many precious gifts b u t a w a y w i t h inanimate objects is not one of them. So far as I am concerned, sexual equality stops short o f changing tyres or replacing washers and, as for electricity, I am like the man who thought there was cold electricity for r efr iger ator s a n d c olour e d electricity for traffic lights. Yet in no time at all I was able to use a s ophis tic a te d p i e c e o f equipment. even t o the extent of programming it to tell a silly joke. Now. I am just letting-up be f or e racing on to looping, graphics and organisation o f memory, w h i c h sounds just the kind of thing I need. Having said that. however. I can admit freely that it has not all been plain sailing. I n fa c t, a t fi r s t i t seemed a s i f t h e w h o l e s e lf improvement plan would never get off t h e gr ound. A 13-year-old's bedroom is probably not the best place t o conduct a n important research project of this kind and my son's bedroom possesses sufficient e le c t r ic a l w i r i n g t o k n i t a fisherman's sweater. continued on page 26 25 wah, c ont inued/ t om page 25 You a r e r e a dy t o be gin, t h e manual said, when a K appears in the bottom left-hand corner of the screen but for that to happen I 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 m a nua l, whic h I cannot praise enough for its clarity and wealth of incidental detail. I had no difficulty with adding 2 + 2, cursors, t he history o f computer languages a n d h o w t o e r a s e 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 cannot remember when I last used it; shall soon be able to dispense with but int e ge r s a n d e x pone nt ia l her services? Things took a downturn, however, functions? The y must have done those while I was away from school with the price of butter and yeast. with chicken pox. Anyway, having Having missed a v it a l piece o f managed without them for so long. I information about semi-colons — thought! might continue to do so and buried treacherously a s I la t e r discovered in that frightening mass skipped to the next section. That look e d m or e promising. of higher mathematics — I suddenly being a ll about the price of eggs. lost control. A stern S f o r Stupid? Those I do use and although I can — kept appearing to say I had it all usually work out their price, give or wrong and when! attempted to put it take a fe w pence. in my head. it right, everything went from bad to amused me to let the computer do it. worse. The trouble is that I am used to a It could even, the manual said, tell 'Unnecessary though a ZX-8 1 may be, what a marvellously clever and obedient little chap it is' me the square of the cosine of the typewriter keyboard, not one which price of one egg, should I ever want moves things about and has about 12 it. Well, you never know. I was glad, instructions pe r k e y a nd erases too, that the manual catered for the backward to boot. I knew you could eventuality o f m y housekeeper pull out the plug and start again but rushing i n , f ull o f concern, a nd that seemed a lit t le drastic. I t crying i n t h a t de lightfully old- reminded me of my one and only skifashioned way of hers: "Glory be. ing h o l i d a y w h e n le a r ne d t o eggs have gone up to 61 pence a negotiate a slope, more or less, but not to stop. To do that, I would throw dozen.• What worries me. though, is how myself int o t he fi r s t convenient am I going to tell the kind soul that, snowdrift b u t I a lwa y s thought thanks to my handy little computer. I there must be a better way. 26 Eventually, it all came clear to me and I wa s 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 t o b e more a matter o f whether Mr Smith was shorter than Mr Smythe. I don't think I had that correct. B y t h e n m y e a r l i e r struggles ha d wor n m e out a nd, besides, there was a good film about to start on the other channel. My studies m a y n o t b e v e r y advanced but I see now how one could become very involved in all this. F r o m t h e s t a r t . I h a v e wondered w h a t possible us e a computer such as my son's could be and I still don't know — but who cares? Pressing buttons is fun. Unnecessary though a ZX-81 may be, what a marvelously 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, I could not stop now. All kinds o f fascinating things have caught my eye — measles programs. Venusians with eight fingers and no thumbs, flowcharts — and I must investigate. If anyone wants me in the next few days, please speak to the housekeeper. SINCLAIR USER J uly 1982 ELEADs A lE; O at . :14T R OUT •x858001 2 1 8 2 k 6 FrGv R E A D - O U T P U B L I S H I N G L T D M e a o r n pThe h o nZX81 is the world's biggest selling computer and, just announced, is its big brother, the ZX SPECTRUM. R e For value for money, these two computers mus t be the best "c omputer” buys on the market - but - to get the o most from them, every owner, and prospective owner, needs a library of books for programs and operations : Read-Out has selected the following bestselling books and can supply ag from stock. i For the Beginner: programming skills to a point where you can really r ZXEll by Tim Hartnell, containing over 80 programs. use machine code easily. The Gateway Guide to the - G e t t i n g 5 34 Amazing Games for the DWI by Alistair Gourley, ZX81 and ZX80 by Mark Charlton is a "doing" book A c q u a n which shows you what you can do with only 1K of describing each function and statement in turn, i n t e d i memory. 49 Explosive Games for the ZX81 by Tim illustrates it in a demonstration routine or program w i and then combines it with previously discussed b Hannell which describes games listings for the tmemory h sizes 1K - 8K. Coming Soon! Learning to Use material. The ZX81 Pocket Book by Trevor Toms o the covers the use of the ZX81 in detail and leads the y ZX81o by Robin Bradbeer and Learning to Use the o ZX Spectrum by Robin Bradbeer - two new books in a reader into a clear understanding of programming. A u r 3 new series designed to help the fi rst-time user (both brand new book is 20 Simple Electronic Projects for T due August/September 1982). The Personal Computer the ZX81 by Stephen Adams which can really put i Book 2nd edition by Robin Bradbeer - an introduction your ZX81 to practical use in a number of interesting electronic projects - thermometer, burglar alarm, u ytoh the world of microcomputing which is generally regarded as the best available. voltmeter etc. Byteing Deeper into your ZX81 by David t Johnson-Davies - the bestseller which tells you how l : aFor the Enthusiast:- Mastering Machine Code on your to get to grips with your ZX81 and with 39 programs e ZX81 by Toni Baker will help you develop your to matc hl THE ZX BOOK CLUB b The Persor 1 1 4' M IL OS Cornputer j a •GAMES m b b , 0 , o 4 • :• : 1 . 11 11 • mud lor T I M He r ti l l i 1 1m A c CC GUIDE 1 11 ON , .4 4 G ZX81 — A A inonnnan A N D 1 M T I H N MARK CNA E A TI ' utio - - - r 4 7 0 . 4„ . 1 P Hot S E Mpti " g r P RO 3 A 1 .. .1 •Foll n t iv: t• p h m o S eb 4 b ti Or l f rt e r ri l o ri Order through READ-OUT PUBLISHING C O M PA N Y LTD S CAMP ROAD, FARNBOROUGH, HAMPSHI RE GU24 SEW. 24 hour answer i ng service. Tel ephone: 0252 510331.'2 Name D Getting Acquainted with your 13011 Ia i f 95 0 3 4 Amazing Gsmes tor the IIC a l l to 1315 0 4 9 Explosive Games tor the 7181 .41 1195 D Learning to Use the ZXS1 E 5•95 (due kna/Seo) D Learning to Use the ZX Spectrum •, f5 95 (cluip Aug/Sep) L i n * Personal Computer Book to ET% Address Make cheques payable to Read-Out Publishing Com pany Ltd. I enclose my cheque for t D Mastering Machine C od. DO VOW ZXIII r. L iso D Gateway Guido to the LXIII i tr7 45 Please debit my Access E Number I I I I ' SINCLAIR USER / lily 1 982 Please send me : c o w r i e s of : All prices include postage. Signed 1 Date D The 2X/11 Pocket Book E S 96 H 20 Simple Electronic Games tor the ZXIII (ft 17 45 Byteing Deeper into your 12(01 ,,, ES 45 Tx 27 Reader survey 1 I n t o which range does your age fall? Under 16 0 1 6 - 2 5 LI 2 6 - 3 5 0 3 6 - 4 5 D 4 6 - 5 5 0 5 6 - 6 5 I I O v e r 65 2 A r e you in employment? y e s / n o If yes, give type of employment If no, state whether student, retired, or whatever 3 In t o which ranges does your income fall? Less than t 5.000 0 E 5 , 0 0 0 to E10,000 LI E 1 0 . 0 0 0 to E15.000 0 E 1 5 , 0 0 0 to E20.000 0 More than E20,000 4 D o you own a Sinclair computer? Which one? Z X - 8 0 E Z X - 8 1 0 Sp e c t ru m 0 How long have you had it? Less than one month Longer than 12 months 0 One to six months 0 S i x to 12 months Li How did you buy it? Mail order LI W H Smith S e c o n d - h a n d 0 If you intend buying another model, which one? If not, do you use someone else's? y e s / n o D o you intend buying one? y e s / n o Which one? ZX-80 Li Z X - 1 3 1 LI S p e c t r u m 0 5 D o you use any other system? y e s / n o Which one? 6 D o you own any peripherals? State makes. Cassette player 0 RAM pack E Printer 0 Keyboard 0 Motherboard 0 Any other hardware 0 How did you buy them? Mail order through Sinclair User Other mail order E Microfairs LI W H Smith Other sources, give details 28 , 1 9 8 2 S I N C L A I R USER t ut ) reader survey To help 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 D o you buy any software? y e s / n o What types? From where? How much do you spend each month? 8 D o you have a special monitor or television? y e s / n o 9 F o r what do you use the Sinclair computer? What other uses do you intend to make of it 10 A r e you a member of a computer club? y e s / n o Is it at school or private? 11 H o w 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 Wh a t other computer magazines do you read? Personal Computer World Microcomputer Printout I] Which Micro? U Computer and Video Games 0 Your Computer 0 P r a c t i c a l Computing El Windfall 0 E d u c a t i o n a l Computing El M i c t o d e c i s i o n Z X Computing 0 S i n c l a i r Programs 0 P o p u l a r Computing Weekly 0 Computer Today CI Any other? State which SINCLAIR USER ! l i l y 1982 2 9 • Plug in — no desoldering. • Space bar linked to space key. • Full travel keys. Si x spare keys for your own use. • Case available to hold keyboard and Z X 81 microcard. • 1 6 K RAM pack clamp supplied with case to eliminate white outs!! THE PROFESSIONAL ZXE31KEYBOARD • All-you-need Keyboard K it f2 8 .9 5 • • Case only E15.00. All prices inclusive of VAT, postage and packing. Please allow 21 days for delivery. fir ZX81/16K SOFTWARE E NO i "STARTREK" £ 4 . 9 5 16K STARTREK: Exciting space adventure game inc luding Klingons starbases, phasors, 8 x 8 galaxy, 4-levels of play, long and short range scanners, etc. E MI LI " S U P E R - W I M P U S " C 4 . 9 5 M ONE ▪ ME I E ME I I E MI 16K S UP E R W U M P U S : C a n y o u h u n t a n d c at c h t h e mysterious wumpus in his underground labyrinth? Intriguing ME I underground adv ent ure. Li " G R A P H I C — G O L F " £ 4 . 9 5 16K G RA P HI C GOLF: Try out your golfi ng expertise, on the computer's golf course, I l•dif f erent graphically display holes. Hazards, include lakes, trees, wind, rough etc. LI " G A M E S PACK 1" E 4 . 9 5 ME I MEE d e DEAN ELECTRONICS LIMITED GlendalePark C Fernbank Road Ascot Berkshire England Dial-a-leaflet 0 3 4 4 7 5661 T e l e x 849242 O M P U T personal c o n E R pu K t e r s o E f t w a r ZX-ARCADE ACTION Y e LI N E W I I " M U N C H E R ! ! " E 5 . 9 5 B At last Pacman f or your ZX-81. all the arcade features plus' software for the OS character board O A " SPACE-INVADERS" E 4 . 9 5 El R the best yet, t he closest thing t o real Invaders on t hi Simply Z.X81. features! including 1 or 2 player option am: D Fulltoarcade software drive the OS character-board. S El "AST EROIDS" E 5 . 9 5 D Authentic representation of t he arcade game including L, R I thrust and fire controls, 5-levels of play and alien spaceships. V " D R O P O U T " Li E 5 . 9 5 . Exciting NEW arcade game. Can you destroy the aliens bet on 16K GAMES PACK 1: Fantastic value for money, nearly 50K of Programs on one cassette. Five games including "Real Time Graphic" L u n a r Lander, St arwars , Hammurabi, Minefi eld, Mastermind. LI Z X - Z O M B I E S " £ 4 . 9 5 16K ZX-ZOMBI ES: Can y ou escape t he manrauding, noneating ZX ZOMBIES as the chase you for your FLESH!!! Eight rounds of play, highly addictive. EMI Mi n M ▪ =E l E NE I I Mi ▪ NE I n MEI they build up in their atomic plies and overwhelm you. Dealers enquires welcome, generous discounts. When ordering 2 or more deduct t 1.00. Send S.A.E. lor Catalord,i, Tick bokets) required. ChequesiPOs payable to "SILVERSOFT", ME Name Address W A N T E D ZX81, Spectrum. BBC Micro Software ( K c elleot Roy alties S A E . r o t detimols All Ar cade games run in 4K S SI LVERSOFT 'Dep. SU7) :35 Bader Park, Bowerhill, •vielksham, Wiltshire_ 30 SI NCLAI R USER l u i y 1982 10 L E T P = 0 20 L E T 0 = P 30 L E T A $ = " " 40 F O R C = 1 T O 5 0 50 L E T 6$=P1$ 60 L E T R = I N T ( R N O * 3 ) 70 I F R = 0 T H E N L E T A = " CL UE SO I F R = 1 T H E N L E T R = " 1 5 FI R “ 9 0 I F R = 2 T H E N L E T A i= " C H E R R Y “ 100 L E T 5 = 6 110 I F I N T ( C , L , E T E ts 1 1 5 1 2 -0 1P R- I IN T A T 1 0 . 0 . E ; A S 2 1 3) 0 F O R FN = T 1 T O 3 0 (1 4 0C N E/ X T 2 F ) 1 5 0 OI F R T - S < 1> 6 $ T H E N G O T O 2 0 0 160 N L E T CS = I NKE Y $ P 170 I F C S = " 0 " T H E N L E T 0 = 0 + 1 180 THEN LE T P=P4.1 IF C S = " P " 190 P R I N T P T 0 , 3 ; " 4 2- 1 " < " " P " 200 I F I N K E Y S ( >"" T H E N GOTO & 0 0 2" 1; 00 N. E" X) T; RC T 0 SENCLAIR USER J ul y 1982 is a version o f t he we llA known c a r d g a m e b u t S instead of cards the program has I three wor ds . ' c lub' , ' b a r ' a n d T 'cherry' whic h appear in random order on two sides of the screen. S NWhen two words are the same, the A two players have to press their keys, M either Q or P. as quickly as possible, to score a point. E The game lasts for four attempts, s and the score for each player is u displayed at the top of the screen. gIt is a simple game but can be fitted into i k RAM and is one of the g few e games of this size which can be played by two players. s t Snap was sent by Tim Crossley of York. s , 31 S n interesting game which can N fit on the basic 1K version of U ZX-81. it is another variation on the the many slalom-type games. M As th e name indicates, th e B'obstacles' are made up of numbers Eof random value and position on a Rpath. The aim is to make as high a as possible. Cscore The cursor moves automatically Rdown the path and is shifted to the U left using the 'Z' key and to the right N by the 'M' key. After a certain length of time the C game stops and the score, plus a H rating, is displayed. It was sent by N page of Kingston E R upon Thames, Surrey. i s a n flLiffla 5 LETA* I m-REEK (PEEK lese.s.aes 6* PMEK 1 6 3 9 9 ) ' 10 L E T X = V A L " 1 3 15 L E T 6 = P I - P I 0 FOR F = 1 TO UAL - 7 5 " 55 SCROLL 60 P RI NT AT 0 ; X ; 6, 5 L E T Q = U A L R . 70 P RI NT "S'' 75 I F 0 4 V AL - 2 9 - O P 0 ) V AL " 3 6 Tr l ets4 G O T O V A L SO L E T 5 . . S + G - V A L t oot I P P I NT A T V A L " I I " , V A L - 9 " ; " 10 I S S E V E NS P A C E 5 1 1 " ; AT V A L " 1 1 " I R N D 4 V AL " 6 - + V A L - " ; I N T ( A N O 4 U A L - 9 •- i . V AL - 1 . 110 LE T X=X-PtI NKEYS="M-)-(I NKE'Y .120 NEXT F Sz --r E H 155C10O5 R 5 I F S-t100 T E N LET 5 =1 0 0 1 6 0 0 p R I N T TAB VAL -9--"ARTI NGs• P , I N T I ( _ U A L - 1 0 0 ” ) , UAL R I N T A T V A L , V A L ” 9 " V— • -• dl .5 R E M - G O L F 10 L E T Tm 1 5 * ( 1 4 . RND) a0 P RI NT A T ao FOR T O 3 1 4 0 P R I N T -111"; SO N E X T J 60 P RI NT A T 70 P RI NT AT 2 , 0 ; - S W I N G . - ; eo I NP UT S UI NG 90 P RI NT SUI NG 100 P RI NT " DP I O E = - ; 110 I NP UT o R i v e 120 P RI NT DRI V E l ao LE T A=DRI VE* COS ( P I * S W I N G / I 301 140 L E T 5 = DRI V E * S I N ( P I * S U I N G / t 220 3W 1 51 6 0 L E T C = . 0 1 * ( 5 * J - I 6 * J * J ) 170 I F R*J>152oe THem GOTO 32 0 180 I F C ) 4 0 T H E N GOTO 2 0 0 190_pLOT . 0 1 * A * J , C + 2 F 200110EXT J O 210 I F ABS ( A* 1 5 / 3 2 0 0 - T) ( 3 THEN TO 2 4 0 RG O 2 2 0 RP I N T P T 1 0 , 2 0 ; " H I S S E D IN t J 230 STOP 240 FOR J = 0 TO 1 m 250 P RI NT AT 2 0 - J , T; " HO LE 0 250 NEXT J T O 5 / 1 5 h : / 0 9 Ni r 4 1 UMBER of attempts have been made to put the game of golf on to the ZX-81 and this one, sent by A Baines of Ashtonunder-Lyne, LanCaShire, is a simple version played on 18K of RAM memory. When the program is run. a *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. a figure usually greater than 300. The traiectory of the shot is shown on the screen and the result. Ordy one shot is allowed each time, which makes it necessary to remember angles and strengths from previous shots. SINCLAIR USER h d y 1982 5 LE T 5 m A I - P I 7 LE T Z = P I - P I 10 L E T A = P I - P I 20 LE T B = R I - P I 30 L E T H = P I - P I 40 LE T N u a l 4 3 L E T )01,21 44 L E T s ( w P I - P I 5o LE T P = I N T ( RND* 2 1 ) 60 L e T 0 = I N T t RND* 3 1 ) 65 LE T R z A + P I / P I 70 P RI NT A T 72 P RI NT A T P , 0 , - G RAP HI C 5 H I F T ED H 74 P RI NT AT R, Q ; - G RAP HI C S H I FT ED H 80 P RI NT A T H oW - G R R P H I C 5 H I F T -E D A 9 0 . P RI NT A T X , Y ;"G RAP HI C S HI FT ED P 95 L E T 5=5.1.A1/A1 . 100 LE T AS =I NKE Y $ 116mir R e . - e - THE N LE T 0 = 3 1 120 I F A $ = - 5 " TH E N L E T 130 I F R e = - 6 " THE N LE T R = 2 1 140 I F 4=16=-7- T H E N L E T R = P I - P I 150 L E T H = H + t H ( R ) - ( H ) A ) 160 LE T N=N* AN. (15)-(N)0) 1.7e LE T x - x + t x ( c o - t x > c o 100 LE T y .y .k or ( e ) - ( N ,A 5 ) 1 9 0 I F =P = HD A N 0D = 0N = O N RO R R. ..N60 O R R H A N THEN G O TO U R L 195 I F R = H AND 8 = N OR THE M v r o e 200 C L5 2 1 0 G O T() J A L - 7 0 " 300 LE T Z = Z + P I / P I 510 P R I N T 315 PRuSE IZI 320 I F Z = 2 T H E N G O TO 330 P RI NT i "DE RD I N 7 - tPx = pXN iApN D0 i0 A = ) < A N D 18 V AL ; , 6 . 0 14/ 1 ; q a. t t xr . „ . 4 4i . for - at ttr a c ti n g bugs i n B programs to emerge wi th U their handst up but a game in which • tempt bugs to fall into a the G aim is to swamp. B To start•the game, press RUN, and Athe swamp is shown in one part Of I the screen with two bugs at random Tpositions and a plus sign in one corner. The plus sign is the bait Etowards which the bugs move. R The game involves moving the i plus sign from corner to corner. using the cursor keys above 5 to 8 so s that the bugs fall into the swamp. n Once one of the bugs falls in, the o game stops and the length of time t taken is shown. If you wish to continue with the a same lay out, press the CONT key. If t you want a new game, press RUN. The game was sent by M Archer o and D Hayes of Godalming, Surreyo k k i t 1 SINCLAIR USER J ul y 1982 33 tor I I I L E F L ot entries tor our May The competition proved that as many ide people are using their Vk-Bis SeTiOUS uses as l ot gatneS. dard variety ol applications was w and all were ot a very high s t a n . That made the tast of the 'Iudges dillicult once more but the eventual Wil l t l eot w ahs l n Fletc her, o f Ilumberstone, LeiCeSter• w h o submitted a system which tiles and retrie Icves information. Ile UPOS it to help e e p t r a c V o f 1 . 0 0 0 photographic slides, with each slide s L i D e SELECTOR 73 Rem FAST 5 REM e Y J om N R. P LE TCHE R D EI M A =S 1( 6 0 0 0 . 2 ) 11 50 L T Z 20 FO R J = Z TO 1000 30 FO R K= 1 T O b 4 0 P R I N T " K E Y DE N O . 4 0 I N c o p e s SO P R i N T FDR sL, 7 60 0 P PR R II N NT T a S640 FO R K u l T O S 4 ti. k70 P R / N T F i s ( S * ( J - 1 ) 5 8 0 4 1 I NE X T K 50 9 0 P R I N T 8 00 0 P R I N T 810 820 830 P R / N T I NP UT CLS 840 850 I F DS = " Y " GOTO 3 0 0 1 8 57500 P I NR PI N UT T "ANOTHER D $ THE N "F Es N T F R S L I G O T 0 C O D5 E " 0 0 34 NO . " e K g MIAT 2 : 4 4 1 1 1 J : i t g 412 0 N E X T 14: 110 I F D l < > " C " TMr si G U I U 4 0 0 LI DeS. ' Y / N a 0a o P R I N T " A R E T H E R E A N Y 15 40 I N P U T DS 1 HO Re s G0 C L S O Z 6S 5 L E T Z = 0 4 - 1 FTO D S 3= "0 s0 r " r H e N N e X T 0 11 76 00 GI O U e N TT OA ST 1 5 , 1 , " K E Y C I F IPN 21l 09e 100o C LRP 8I U S I S O K , O T H E R W I S E NEW1. . 1-Ne" 210 8 RETURN 2 2 00 F O R K = 1 T O 6 I NT 0 ; " 'KT J THE PR . 0 NrEP) < ' A t e l F ( J - 1 ) + K ) z - F $ N etc) T i K 260 RETURN THEN N E 0 P R I N T " 2320 I a a o I F $ ( 6 * ( 0 - 1 ) - # - K ) = F $ 5 3301 P P R R i a a N n t f t 4 M A W Key M P U L O V U r 340 P R/ NT "FOR I ND-I C/ I -DUAL S L / D E des, lt is possible to obtain lists ot slides W i s 11E003 up to three codes be in common. co Fletcher said he d bought the are i 7.)(-Eli wi t h the intention of r o ducing such a system. Ile and his n wile had so Illany slides, which t g used to illustrate lectures, that i difficult to sort them. d Was Ile was able to write the program, e listed here, a l t e r hav i ng t h e s machine tor only three months. hEiv e alw ElyS been interested in c computers and learned how to use r the 1%.-81. very quicly," he sa d i.the Ile added Lthat O Nlive I Tminutes i n g and i SIOIBing time was b u t b that was nothing compared to e time needed the previously t o s ort d through s l i d e s . The system is very general and b be used for other types of f g . y s 3 5 0 PRI NT KE N i 3 I N , 8 = x 0 KEY R 3 8 0 Px R I N T h 3 9 0 Pt R I N T KEY . 5 a • 0 0 p7 R, 4 1 -0 . 4 1 ••• 1 . e P R I N T E t aS K E Y A L SLID 4 - a e l P vR i i \ r r 4 2 2 P -R I N T w e KW D S A V I N G P cR O G R A M ,Z N T o 4 3 0 P R Iv N . T T D KEY C H A N G I N Gi P R O G R A M 440 I N P U T 450 CLS I o l N 460 I F A = 0 THE N G O T O N e 4 7 0 I F A = 1 THE N GOTO 480 I P R = 4 THE N GOTO t 4 8 5 I F A = S T H E N GG O T O 4 I P P . % T H E N L I S T 4 g 0 t -S O O P R I N T " K E Y I Nt 7Q 1 0 I N P U T J e 520 CLS M i 5G 3 0 P R I N T " S L I D E r l eO F O L L O W I N G " o S 0 P T "CODES p 5T 54 0 P R R II N N T O "CODE D E ? y i N , Pr' • 0 PRI O1 F . 5 g 0 P P 1 N 7 T 1 -„c. - Tr ie N GOTO e s e . _ 0 700 GOSUS l oou 6 76 I f D r - I - 1 , T ,o f s L 1 D e 5 H p v l ‘ . 1 72o P P V .t : .1 0 0G7c3ope 0 ppi t 4 - 1 _ _ 7 4 . 0 r o p ...1 1 2 1 1 _ , , 7se G o5 ue w '7 6 0 1 4 C * 1 . , J _ _ _ _ 770 0 0 1 0 2..ss_re.R r I P5T CO O se 600 P P I t q F v . 0 1 0 p° e " o. N 0 P I N 1 r_ . ' 5 2P a 3 . 0 p p I o , 1 1 _ 0 4 T e R 5 e 0t ) 35140- 0 I 0N0P5UU_6T 8 , , i o e t . 4 C 650 I f D 4 ) O PI NT -6L3-70 06 0 PI N PU 3 6 0 * P RI NT T O e I f v m a THe s Goswpo c o o , S9. .120, I f 1-1- , , v4-1-eS T H I O9 3- 0 P S I N 1 - r i s , r N G o T o etoo V aS t f ) t4-11 t S 0 0 V , eGD I f w l . . I . J 5 1 017. s 4 . ) 4c7 o 1 "p eTst I: S S 6 t - 1 0 S g A k r i t - i N(N3 _ i W9 9I 0 r P( )P* 1I 4 o t - LO ‘ gc r w e G1 .r0O0 0 P P I t o r . ; . . , A l 4 ° _ 4'' _ • P R I N ' T 0 9 1020 -'1gi f-f-10. 41p2OTO 1 0 0 1 0 6 0 F074 . . . 1 T o 6 0 „ 4 6 l oe s Go 0 1°1e r ° P1054tJ-1)4, 1060 I F L l • a l 5Ue te go ax t. 1111(640J-s)4. ool ' a•• •i 't o TH e N N ° 1100 NEXT L I 0 GOTO 1 2 0 0 1I 1I Q 1: 1 3 T o z 1240 )-OR mwl 8 r1 o / c .111111 75 0H Ie Px TA oH( 6 4 T O ( J - 1 ) 4 4 1 ) w Hi l i 0 NEXT J t7a0e o #. 44z wi l .161 2 1 0 P R X N T 01 3 P R I N T 2 c2o p e - , Y , , N 0 0 I F Awl THEN pRI NT T H E N G o "ANoTHeR o f P U T O S 1 i9ts958e00T C I N 1 -Q 4 0 I LP S A f . 1 1 T M e N P R I -eCi neO 11N 99O9T7 00& G "I PA 0 N 4 1 1oc >T" ) rH- Te H A E N GOTO 3 0 0 L e T OTO 5 0 0 e I JP w0 4Z0 f t " S , " R N O P m / T H E N 0 0 T O 11 39 550 10? - Y 1 H1e3 N LO W TI N G 1P 0r O"PL R I N - L- R S T S L I - O e A D D e 0 W R S 11133343a0e PP PRX I/ N NTTT -- s L r o e N o . N 1c- 3 o5 0o eP O i s PT : "0 , ( wO 0 6 137• N e ) c r i.c % 4 . ( 5, ) - 4 ' 4 0 4i a;3m 6 s0e. 1P m ;R i" 4I zNwTr1 0 1 4 6 ,0( 8 4 1 3 9 0 P R I N T e zi_zoesI NL P5 O T r ). 1 k I14411M0 C 1 4 0 0 P P I N T " P P E S S N--. 1 _ T O 1 4 2 0 G I S 0 0 C Lo 5r o Q 0 A 0 0 NO R a3 01 C N PP U T ORST 1 0 , 1 0 ; - S T A P T T A P E — 11I16 1 00O 1X S54R P1L RPS Z NI N 1T - r R e 1 0 ; " R e Y Nr . i . . " iI sS eS ee L eE r O S Ds S4 - S L I O E 5 U A 1S70 GOTO 3 0 0 l eo0 REM S LTO 1 " s e L e c r o P as • • p sneezing sand coughing. Igh mixture. must gar gl e a n d t a k e a n bed for a your d a y Or two and temper atur e regtz.3b. put the thermor under your tongue. Ver a t ure is . 44 San* macibrituil. Sans r atti har,j. „ A C eaded The e ttt A ? T I V R h A I R D R P : S S E R ' Sh stitt see the scar b u t y o can e u thrgtrbt Nob r I./ cannot . must dress your wounds cana honor re-akt/hin &i m a m i dati n ti tygr yar (or ti tr ayr or ) tintrud claws 1-iikfibba. trattnna t • oh? yom,5011 nta sy-ttC114 tior6rtak bsinu;d ta tgar tak om. Cirtifdat 11 d a m s * i r m " - - tathtt-t imoronin a na k UpSitborci - Ii .tt tt ,is very weak. e e ube taken t o • tat )mr i l e u r e it m us t n doi n i c so CSIS1 I . S .1 1 n te t Vfees fora i • %tot 'n v •k end throat S lit d i s c a & S Oh P I n • c a re t o g i r .a a cl i t yv s to take a P l m . m i SIMPLE learning program has C i • iion n al l r i g rkas no go, sc( been introduced by Andrew 0 at randa tea,% Wilson ofPutney. London. lie i n 1. e( has called it Language and his verga sion can be used to help vocabulary in foreign languages. ,fOnly. du t your ar When the program is run, it asks for a e teep y o 10 foreign words t o be t y p e d I. v r u followed by their Engiish translations. it rs s k i nt The ncl coot i n . foreign words then appear on the screen and the user's required to inset t i the English e W e . correct conments on q u i v or a lnot. e whether they ar e nts he ; It is ideal for someone wishing to 113H est themselves on a group of words c . t wish h toe learn, or for someone who they ose p r to o ii ishes set a test for someone else. r with a a little ingenuity it could r. ogdoubt d:s1. m extended to cope with more words. r as) I V As it is for the user to decide which ords ar e put in. th e possible nations are I endless. I t is also ssible to ex tend the system to olve other subjects. such as simple thezna ties with a problem a nd wer being for someone whose e fentered f l e f I C. 3 1 T • . 4 4 A 1,0 0 1 - 0 0 u , 0 wt -01‘---yiessetkac• 8- c0,,,teovor.gt . x ..,;ea,tlocv S- s _grecVele‘t c boAt c'I' t _ t" . h we s' s•Skalf'c . i blo,1s, 9'111.s—,get. b e tz e ivveissetIL i _e) e lNsvest. vs.‘issc,,,fuv0- c k „ e a 7 l L l : sKi,c19.% vtaw• ekt 5 ' I ' " vj t c, t , i k . v n e1.1"..,sa•• f wvc%" t AV s 8 ; ; vAdaer"' Aco' - "t•• -1'-b ' -tto‘t c ..,'" . t k s A t Nodes' _ , „ Vos • aNwtsoc-t.• 0„ P-8 % A,-4.00' _•-,,•. o- o •--• icftc111 ' * x - -..,,m••• -vva °V , e 5 36 61 k • - \ i d locm . 10 dis 2. s mi n di•% 1 oft. s m a ( loon . S P E N " L A N O . " R m FO RE I G N WO RO " ze i NPu l o P P / N• r r RS T R S c e ) ; R . r N r 1-N YOO • f t e I N g q . y0r C T D- R N O R N O T H E R N i N e . 6300 i PNRPI UNT 740 0 IrNp N P UuT%r ee NP PU U TTe P S 95i00 II N GS 0 0 T 1 I N P U rH S 110 I N P U T I S 13 Z0 0 C I NL P3 U T ( , J $ 1 a 140 PPUSE 2 0 0 'T i r 116600 IPNRPI UN TT K' NS O W P R I N T T H E E N G L I S 1 7 0 I N P U T eL S 160 / NP UT HS 190 I NP UT NS 200 I NPUT OS . 210 - I N P U T P S .'0 I N P U T O S 00 I NP UT P S 2S0 I NP UT S S rs 2280 7 0 rt,ipur CL5 200 .T H E S E v uu - (.;-. r i . s t a e 3r310 PAO1 Y * * -* *O* O :7 *lo * *,1 * *2* 1 " ; - ****# *****# o - P0 E1PPRINT Li2j kl . 7U S 6 SRT ' o 1tdis .e) t re I t SC. C. rr d• dr v • 1 Rrn a m Ihe • t3 re Pt71"4.r -41t43 P 00 33de 00 6Se C LRSU S E 3 -3 6 0 P R I N T R S a70 I NPUT RS 3 9 0 P R I N T EI S F -P U AS 43 0a 0e I2 N T = SKSS T H E N G O S U S 1 0 0 0 . 1. 0 P R I N T C $ ST S =CL SS T H E N G O S U S 1 0 0 0 444 431 000 II NPP U hed- A L " C '' e t • IS C 0° ss i m 1.(1 2R 90 PRI NT R E W NO W I k L Z PE O RSE"I G N " " 1, "10;1'06 r LY P ou ttsits disp d i saru P W ( o dtmfu Pa 1 di sPcn" 1 disPc %di s P c d 9ns o distr " disPt 5 s•./ 2 di st 1 , -( , di'0 i c t i n e • Os Id"' oscr " nge otoc• dtspos 280 PAUSE s can then b e -tin d by theprogram. :tc Yscheckedirrunediately ,,,, v it s •) - v o2os 1,°%) fk tc to . 1,c t)'c-t% •I'cstk ( 4,4 9° .'?,.,11116 ,.a ' ' t t,, a tt.eidec _tatetl _ ..y.ccos•Pt , 1s'st( w _ dt t -t;kill!ITt., C loaes It' 0 • oa.• l IsiC0t;:r_cle2°,1IcileTe aeet e"sf _ ceri.:,-111 tode t t l co01-•b e rs iu V V ct ee t t ° l ‘ • As t° 1 1 e ) ' C t 'tttIVe412.1s2L• OCN" - " % e f W / 1 , t , "I f el% ',o ,,e8kb b t t i l s i c • - - s H3 1 - - e t . , sbe,t Vs9, tosteost; t p , , , stor '!" ) ,,, . e- al lelazitzt a -orb411tP1- • Cana w st ti d. . a lYour i e is dealhear Well. dumb n i n n e r ear is I* arnshor . infi A a m • V-•• t s i g h t • - • po — 4S0 P RI NT DS I FP U CT S =DMSS T H E N G 0 8 0 6 1 1 0 0 0 460 I N 480 PRI NT ES O TS N S 41..70 9 0 ITNr P U r s T H E N G O S US 1 0 0 0 S I NP E Os S T H E N GOSUS 1 0 0 0 s5 TT = P 6 a0 1 e0 0 IP RPI U NS P -40 PRI NT GS PS P$ S T H E N GOSUS 1 0 0 0 3 6 0 I INPP U T rC $70 PRXNT HS PP , UGTs =HoSs T H E N 0 0 5 U B Ss8600 II N 1000 I . tof ate', nfl ut (1. P . he a l. like ss i mi mlasisY• oi lscatt. t ca11t t o dl s ; s a gr % sisccl„rdt t;diri s eon.O eum . its e . . se r tence; t disseo u ant i ( s• )r hiddensrcte‘. i" tan) b )di " vol e. d to ). iast 's dissemble . °. 6ee PRI NT I S HS .55 91 00 II NPP U T =2R- S $ THEN oos oe l e e e 620 IP. I S S 630 P RI NT OS 6 4 0 I N P U T =J S S T H E N GOSUS 1 0 0 0 660 STOP 5 N RT N " C O R R E C T " 11 00 3Z 00 RP ERTI U 4 , o 9 • ' , -sMiting I NJ' t 0 I a . re 9 •94 , t F -kar n t i q\e elstcar,t irlit Ill c - la, _t , s rI n t , t e-Chno, vo 0 k,„ . . n o v' .. e. 0 h, -pe — d x 1‘ Vo , 1 P O7eS t V 4tstsvo s t"qc.4 ' , , r ,nc a / t o t • g tPII , - , ,r,",S -t ' '4 1 " 1 l c i ' s o, P o t d o u r r- e r , r z%- c n SI NCLAI R USER J ul y 1982 n o lt r v. a ,,,,' •e u c' e v v Hill, London, Sheepdog — a difF ficult game whic h is a good R representation of a sheepdog trial. O A sheep, an inverse S. is driven by M a dog, an inverse D, through a gate. denoted by two black squares, and D ainto a pen which is shown as a grey nsquare. The dog is moved upwards pressing the '0' key, downwards iby by the •.• key, left by 1 and right by 3. eIt continues moving until the S is lpressed. S When t h e dog i s wit hin fi v e hsquares o f the sheep, the sheep abegins to move. The difficulty is that vthe movement of the sheep tends to as wayward as any sheep in a ibe real trial. c A fte r a g o o d d e a l o f kconcentration, t he sheep c a n b e openned a n d t h e t im e t a k e n i s fdisplayed. A s a guide it took our reviewer 1 ,0 7 9 seconds — one M isecond short of 18 minutes. l The game can be re-started by pressing NEW LINE. l SINCLAIR USER J uly 1982 le PRINT A T 1 9 ,2 9 ;C H A $ 1 3 8 ;A T 1 0 20 L E T 5 = 0 ; 30 L E T R $ = " " 0 LET DH=21 5 ;S4 O LE T DL=5 C be L E T S H = 5 LET 5L=25 H 57 00 L ET Z=5 R 90 P R I N T A T S H ,S L; C H R $ 1 8 4 ; A T D H ,D L; C H R S 1 6 9 S1 00 I F 5 H = 1 9 AND S L = 2 9 TH EN GOT O 1 11100 0L0E T 5 = 5 4 - 1 2 120 I F I N K E Y $ < > " " TH E N L E T A S - I NKEY$ 8 130 I F R $ = " " T H E N GOTO 9 0 ; 140 P R I N T A T D H .D L; C H R S O A T 5 H o A1 5 0 P R I N T A T 1 9 5 6 0 L E T DH=DH-1.(AS=CHRIN 2 7 A N D D T1 t H< L 2 1 )-(A I=C H R $ 5 2 AND DH>0) 12 9 ; C H R $ L=HDRL.( A CD H RD$ L 3> 1 L4 ; 13711 I-L( E A Ts =DC $12 9 SA= N 0 )A N D D 0 1 80 3 I F A6B S ( S H - O H ) = z O R A B S ( s C L ) > =Z T H E N G O T O 9 0 , -1D9 L 0 I F A B S ( D L - S L ) <Z TH EN L E T 5 H L 1 ( 5 L >DL ) - ( S L 4 D L ) R2 0 0 I F A B S ( D H - S H ) < Z T H E M L E T 5 1 (SH >D H ) - (SH <D H ) . 1 0 L E T SH=5H4. ( S H ( 1 ) - ( S H ) 2 0 ) ; 2 2 2 0 L E T S L =SL-t- ( S L <1 ) - ( S L >3 0 ) C 2 3 0 I F 5 H = 1 O A N D ( S L 4 6 O R S L >1 0 ) THEN LET SH=SH-1 H2 4 0 0 0 T O 9 0 0 0 0 P R I N T A T 2 1 , 0 ; 5 ; " SEC ON D S" R1 1010 PAUSE 4 E 4 S1 0 2 0 C L S 1030 RUN 1 2 8 37 program for users of the W ZX-80. It is a version of the E well-known game o f Mastermind, I where four numbers are picked at N random by the program a nd the player ha s a lim ited number of C attempts i n whic h t o guess the L numbers. U DTo guide the player, the program marks each attempt by bulls and E cows. A bull denotes a correct a number in the proper position in the s sequence and a cow means that the p number is correct but in the wrong place. e cThe game continues until the correct number is guessed or the i player has had 15 attempts. Press a f o r another number t o b e RUN l guessed. Bulls and Cows was sent by G Gill of Westerham, Kent. 10 Di m N (4) 20 FO R A = I TO 4 30 LE T N(A) = RND (9) 40 NE X T A 45 FO R A = 1 1 0 4 50 FO R C = 1 TO 4 60 I F A = C THEN GOTO 100 70 I F MA) = MC) THEN GOTO 20 1130 NE X T C 110 NE X T A I 20 LE T A = N(1) • 1000 + N(21 *100 + N(3)* 10 + N(4) 130 P RI NT "ENTER YOUR GUESS" 135 FO R 1 TO 15 140 I N P U T BS 141 142 143 144 150 160 165 180 190 200 210 220 225 230 240 250 260 270 280 350 360 400 410 420 I F BS = " " THEN GOTO 360 P RI NT BS " ; LE T B = 0 LE T C = 0 LE T AS = S I M (A) LE T X$ . AS LE T CS = BS FO R S = 1 TO 4 FO R D = I TO 4 I F CODE(XS) = CODE(CS) THEN GOSUB 400 LE T CS = TLSICS) NE X T D LE T CS = BS LE T XS TL.S(X.S) NE X T S I F B = 4 THEN GOTO 350 P RI NT B; "BULLS": C; "COWS" NE X T F P RI NT " I LL TELL YOU THAT IT WAS"; A P RI NT "THAT'S I T" S TO P I F S = D THEN LET B = B + 1 I FNO TS =DTHE NLE TC=C+ I RE TURN • 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 one month of despatch, it is unlikely that we will be using your submission. SrNCLAIR USER J ul y 1 982 ZX81 users I need more memory! please rush me t h e fully assembled, tested a n d guaranteed 'BYG BYTE' 16KRAMPACK N am e A d d ress Ma k e a l l c h e q u e s & P O ' s p a y a b l e t o : P hoeni x M a r k e t i n g , O a k l a n d s H o u s e S o l a r t r o n R o a d , F a rn b o ro u g h , H a n t s . T e l : ( 0 2 5 2 ) 5 1 4 9 9 0 FULLY INCLUSIVE PRICE E25.00 PERSONAL S OFTWARE SERVICES ESSENTIAL PROGRAMS ALL YOU NEED TO SIMPL IF Y CO MPL EX PR O G R A MMI N G f6•95 r 1 A M UST FOR ALL SERIOUS PROGRAM WRITERS ENHANCED BASI C I S STORED , ABOVE FIAMTOP AN D SO ALLOWS YOU TO OPERATE ON OTHER PROGRAM S 0 SOME OF ITS M ANY FEATURES INCLUDE AU T O RENUMBERING IINCLUDING ALL E GOTO 5 • GOSUB'S), BLOCK DELETION OF AN Y PART OF A PROGRAM D I SPL AY N THE AMOUNT OF MEMORY USED SAVES HOURS OF TEDIOUS PROGRAMMING OF H A £6.95 1 6 K N 1 / 1 Z X COM PI LER C AUTOMATICALLY TRANSLATES A LARGE SUBSET OF BASIC INTO MACHINE CODE E WHICH I S THEN STORED IN A REM STATEM ENT FOR USE AS A SUBROUTINE IN D ANY PROGRAM YOU WRITE. OPERATES ON 35 OF THE MOST VALUABLE SINCLAIR B BASIC COM M ANDS INCLUDING PRINT CONDI TI ONALS. POKE. GOTO. GOSU B A FOR LOOPS ETC ETC. S I £5.95 C 1 / 2 G R AF ix 1 6 K 1 6ESSENTIAL FOR THOSE WH O NEED COM PLEX I M AGES I N THEIR PROGRAM S kSUPERBLY EASY TO USE. WHEN YOUR DESIGN IS COMPLETE IT CAN EASILY BE INCOPORATED I NTO OTHER PROGRAM S I M AGES CAN BE STORED R EC ALLED AT AN Y TIME, REFLECTED (SE MIRROR iM AGEI M I X E D TOGETHER Y O U C AN CHANGE THE FLEXIBLE c o L o uIMoA GE r P IROCE S S IV 4 A V A IL A B L E + P R O D U C SPECIAL OFFER B U Y AN Y T WO PR OGR AM S FOR ON LY E ll 50 OR AN Y E THREE FOR 115 00 I THE N ABO V VE PR OGR AM S AR E ON L Y A S M AL L SELECTI ON F R OM OU R E WIDE R R AN S G E O F 1 X8 1 SOF T WAR E - AL L O F WH I C H I S AVAI L ABL E E THROUGH THE Z X SOFTWARE LI BR AR Y S A E FOR FULL D ETAI LS. V I D E CHEQUE OR P O . I O T O M P S S • A 1 1USER J u l y 1982 SINCLAIR G 2 E O L I S V E R DEPT. SU OPENING SHORTLY A retailer for Sinclair accessories in the Yorkshire/ Lancashire/ Humberside area. We are situated close to the M1 El 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: MO N DAY to SA T U R D A Y, 10am to Etom 39 t t it t t lt t WHI P 117,11 THE t l i t i I t t Nr p Tir I I l l lit 1 , 1 . 1 1 ilt i t it I 1111119111110H1•11. BUFFER MICRO SHOP (NEXT TO STREATHAM STATION) NEW SOFTWARE SHOP EXCLUSIVELY FOR ZX131 PROGRAMS. GAMES, "ADD/ONS" Micro Fair and Seminar for all users HARDWARE. SOFTWARE. PERIPHERALS. MO S T OF THE MAIL ORDER ITEMS ADVERTISED IN THIS MA G A ZI NE AVAILABLE OVER THE COUNTER LOADING PROBLEMS? TRY OUR INTERFACE BUSINESS & TECHNICAL DATA HANDLING PROGS PROPER KEYBOARDS; CONSOLES; VDUS UNIVERSITYOFMANCHESTERINSTITUTE OFSCIENCE ANDTECHNOLOGY,SACKVILLE ST., MANCHESTER SATURDAY 24 (10.30. 21.00), SUNDAY 25 (10.30 - 18.00) JULY 1982 374A STREATHAM HIGH ROAD, LONDON SW16 Tel: 0 1 - 769 2887 IU 21) 313 SC so 70 St ?1) 11313 1113 FPSS 0 1 0105 1 819000 e t i i i sae Eey 9rW FP f S oScosplitigg P Esview L1i511611CleiPgpsagem M I LeCI I 3P68 Cit 8 0 4 1 1 i l aCPC SCIPliC51111:1610 O FRISEFilms E9P sod peRsztimsate C cM t nc tc csitiPS sod Piccsdilly aFre Ovcr r es Iscilitise 1131 e l 1 the eE l pl e s S.A.E. APPRECIATED FOR CATALOGUE ZX81& 80OWNERS ACCESSTOTHE OUTSIDE WORLD' SPECIALISEDPRODUCTSMODULAR EASY TOUSEFOR HOME/INDUSTRY&EDUCATION b l e d ADMISSION: .M ADULT CHILD(under161 1 0 5 0 (halfprice withcoupon) 0 p Exhibitionandotherdiversions for ZX.B.B.C.Micro,VIC,IRS.Sharp. Sorcerer.VideoGenie.Tangerine.Nascorn,Atari.PetandAcornuser 40 ----. ------ ItIO INPUTkUTPU1PORT E a s y to uSe r t oetween ZX & RAMPACRiPRINTERit? reothiedi No skill requited to connect Can be used tor sect) things as motor control sounamusac generators connecnon to or intersilleoPI discsAign/ pensmtner computers temperaturemonitoringsqu a r m genera/mga 'control at potabogaerials even tramseeseic re Pori has 16programmable Le Hoesandmaybe usedminuetanyelectrencs knowledge toconnect other add om Motherboard moundONLYwhenton) or more addens are usedatanyOnetime ASSEMBLED11795 A i l 0111)40111CASE E I495 TE12 4CHANNELRELAYBOX T o suit port Contactcanna 240. ACII 5A 240C or 110v ATIA Up to I urn% m 111•1111 e 1 6 8 WAYTRANSISTORDRIVER 1 9 95 O 8W r eH l Ma y sAYSWITCHUNIT(EDUCATIONAL) - 112 95 K U M 8 WAYINDICATORUNITIEDUCATIONAL1 E 1 2 95 c a m • i i i l l TOISTICK&FREEGAME 2 icresticksmaybe connectedvia Motherbowth t 12 95 bTI Me MOTHERBOARD Allows rendbplescombinations 0 addmet u p toll lines may boeused p E e 1 5r 95a 6 r e d u n e d tor useD 0 ad t3 a C t e d 1 1 " 1 POWERSUPPLY2 3WA 46WAYSINGLESIDEDEDGECON7El 95 E X T E N D E D P ID NOTTS El E1 5 PRICESINCLUDE MT 9 Y Receiptsalwaysprovided Delmer, 1 normally ex steel ACID51)pMoods p&ponall orders une. 5 1J1211wroththe exceolion 0 accessories e gEdge con FIA 1 0 poducts 9 2t S i TUE LI DRI a n d 9 c o m p l i e s o e •••-•nS AE EO t N CA• * r_ , 1 X - SITUDNALL IIL ICT RO NO CSi EOM m DR I ELLA.. • D E P t C I S ( M A R GO T RO AD S ••LS ACCE CAO IST RAD MALOCHESTER OWE S I D i , EdgeC m a i285TEL CO I.?T S Alial t T C o n t w a c t i SI NCLAI R USER J ul y I 982 c l t u n h w ,7T - = INT R T T r z Y sr R I _ 3 ••• _TNT R T T + C t' = U R L UR • 'MT n ' r 1= t_ T 15E 4,) L R F- • 1NT R T GO 5 U 8 1P11 '2 " 1T H E t 0 1"S = " 3 E Y — ) "0 3 — — T t H E N r • 1-.1 S U N L E T E 1 ( 4. 1 , Y ;CHP $ program aids 1 5 G O T O 1 OT 0 U R L 5 - , 2 The popularity of writing in machine code is growing. Phil Garrett looks a t the systems which can help. Aids for speed and efficiency Space Invader-type a r c a de j games for the ZX-81. a nd of books U such as Toni Baker's Mastering code on your ZX-81. it D machine seems the ZX-81 owners want not G only to run machine code programs I write them, too. That is scarcely but N surprising, considering t h e t r e G mendous speed and efficiency of a machine code program compared to b Basic, b u t the r e i s a tr a de -off y involved. t I w r o t e a three-dimensional h Noughts and Crosses program for e mypZX-80 which played a good game buto ha d a response tim e o f 4 5 seconds. A year later I wrote the p program in machine code on same myuZX-81 and it had a response time of lless than half a second. Writing a program, however, had taken that eight r complete days of my summer holiday. i t Broadly speaking, there are three y types of program available to aid the budding machine code adventurer. o The most complex a nd probably f most useful programs are the assemblers, w h i c h c o n v e r t mnemonics into machine code; then there are disassemblers which do the reverse a nd, finally, monitor programs whic h a llow close e x amination o f a m a c hine c ode SINCLAIR USER J uly 1982 program a s i t r uns , plus othe r functions. When Zilog produced the Z-80 microprocessor, each o f its hundreds of instructions was given a mnemonic s o tha t users could remember w h a t a p a r t i c u l a r instruction would do. For example, LD A , H means load the Accumulator wit h the contents of the H register a n d represents 1 2 4 i n machine code, T h e mnemonic i s entirely arbitrary and could just as well have been LOAD A FROM H. We c ould produce a machine code program by POKEing instructions byte by byte into RAM a nd plenty o f machine c ode loa de r programs do just that. The method, program for Basic keywords — CALL — and then places the corresponding instruction in the RAM. The ability to use labels makes an assembler v e r y powe r ful, a s i t allows the programmer to refer to instruction lines, subroutines, and even da ta b y means o f symbols, rather than having to determine the addresses each time. Sufficient of the theory; how are the ZX-81 assemblers used? BugBytes ZXAS assembler is in 5K of machine code, with a few lines of Basic to operate it. The program resets R A MTOP automatically a nd loads i t s e l f a bov e i t , s o t h a t assembler source programs can be loaded and saved separately. Lines of mnemonics are entered in REM statements, wit h multiple instructions allowed, provided they a r e separated by semi-colons. Up to 256 labels can be used in the form :LO to :L255, and comments may be placed after a " * " . Full-stops a r e used instead of commas — e.g., LD A. H — which makes typing instructions easier and numbers may be entered in de c im a l o r he x . W h e n t h e assembler is run, you are prompted for t he starting address f or the resulting machine code. Invariably I use a REM statement at the start of the pr ogr a m , a n d c om pile t h e machine c ode f r om 16514- T h e 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 a n 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 a nd stops with an error code, so it is not time-consuming i f the program is difficult t o build a syntacticallysubstantial. On the other hand, an correct source program. There is at least one bug in ZXAS; assembler program converts t he mnemonic form of instructions — the SUB A ,n instruction does not which we can understand reason- work but it can be replaced by AND ably easily — into machine code A; SBC A,n which does the same. which t h e microprocessor c a n ZXAS is a remarkable program and is excellent value at E5. understand and execute. The only other ZX-81 assembler I In some wa y s t h e assembler have encountered is produced by program is similar to the Basic ROM continued on puge 42 in the ZX-81. The ROM scans the 4 1 T continued from poge ACS Software. It is similar to ZXAS in s i z e a n d o p e r a t i o n , w i t h i n stru cti o n s e n t e r e d i n R E M statements and labels available i n the form Q.1: Q.255:. Data must be entered in decimal rather than hex — I prefer decimal — and there is a useful D M function which a l l o w s y o u t o specify th e contents of a particular byte during assembly, so you can have messages embedded in your machine code. The assembled listing display is slightly di fferent fr o m ZXAS: you are given the decimal address, hex opcode a n d d a ta , a n d th e n t h e mnemonic. The A C S a s s e m b l e r i s a l s o excellent value at E5.50 and the use of either this program or ZXAS is the single biggest step to proficiency in machine code programming. Neither program sets out to teach assembler, so a book w i l l also be needed. I u s e t h e thorough b u t expensive Programming the Z-80 by Rodney Za k s b u t th e re a r e n o w several books available specifically to the printer and you have to use the break key to re tu rn to Basic. Machine code can be entered, and individual bytes changed, using hex. This program, p ri ce E4, has been available since lune, 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 s o f t w a r e f r a y w i t h i t s disassembler. I t i s a v e r y l a rg e program (14K) a n d r u n s a l i ttl e slower than the others. The display, which can go to screen, printer, or both, i s u n u s u a l ; a d d r e s s e s , contents a n d mnemonic d a ta a r e given in both hex and decimal and the display allows one line for each byte. There is also a facility to enter machine code fro m address 30000 in either hex or decimal and an Edit function to a l te r a byte o r copy a block of bytes from one area of RAM to another. It is good value at E3.50 plus 5 0 p e n ce f o r postage a n d packing. Bug-Bytes Z X D B 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 i n t o mnemonics, ma ki n g i t easier to analyse and amend. The ACS disassembler can be used a t the same time as its assembler and provides mnemonic listings i n th e same fo rma t. A l l addresses a r e shown i n decimal and destination addresses a re shown f o r relative j u mp s r a t h e r t h a n t h e displacement, which is an excellent idea. All the other disassemblers have additional b e l l s a n d w h i stl e s t o assist w i th editing and debugging machine code. Campbell Systems 4K disassembler uses plenty o f Basic and its machine code occupies my favourite 16514 onwards a re a o f 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 S I N ZXAS assembler and occupies 4K from a d d r e s s 1 6 5 1 4 . I t svo rks entirely in hex and does not dump to the p r i n t e r , a l th o u g h y o u c a n circumvent th a t b y disassembling 12 lines o r so, then calling 08691-i, which i s th e Sinclair ROM COPY subroutine. Another disadvantage i s t h a t 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 mo n i to r f u n c t i o n s . s o I h a v e included i t among the monitors as well. ZXDB costs E6•50. Mi cro Ge n D e b u g i s a l s o a disassembler w i t h so me mo n i to r functions, works entirely in hex, and can be used with a printer. Care has to be taken when transferring from Basic t o Debug a n d back, o r th e ZX-81 will crash. I found the monitor display impressive, although more detailed instructions w o u l d h a ve C L A been h e l p fu l . Th e p ro g ra m l i ve s above R A M TOR w h i ch i t re-sets automatically, and costs E3.95. ACS junction w i th th e ACS assembler and disassembler t o p ro vi d e a Deb complete, i f r a t h e r e xp e n si ve , ug machine code w ri ti n g package. I t stocre s a b o v e R A M T O P . u s e s a decimal numbers only, and does not n dump to the printer. Once again, i t costs b E5.50. The Pi ctu re sq u e Z X - M C i s e another sophisticated monitor: i t is u rather l i ke a separate operating s system. You cannot use i t with any e existing machine code programs, as d it uses low memory and has its own i in high memory. It has its own stack loading n and saving routines which operate a t tw i ce the speed o f the c ZX-81. Th e program i s complete o with a comprehensive manual fo r n £7.50 b u t I believe i ts incompati- w i t h o th e r p ro g ra ms i s a bility serious disadvantage. The Taurus Machine Code Monitor 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 f r o m 1 4 K R A M p l u s 2 K monitor to the full 16K RAM. Apart from th e usual functions, i t has a helpful hex calculator and a facility to cre a te REM statements o f any length. It also has a comprehensive manual a t E7.50 i n cassette form, and the RAM-pack system costs ELIO. Bug-Byte, 98-100 The Albany, Old Hall Street, Liverpool 13 9EP. ACS, 7 Lidgett Crescent, Roundhay, Leeds LS8 1HN. Campbell Systems, 15 Rous Road, Buckhurst Hill, Essex IG9 681. Aylesbury ZX Comput er Club, 12 Long Plough, Aston Clinton, Aylesbury, Bucks. Mic roGen, 2 4 A g a r Cres c ent , Brac k nell, Berkshire. Picturesque, 6 Corkscrew Hill, West Wickham, Kent BR4 9BB. Taurus, 4 7 H i g h S t r e e t , B a l d o c k , He r t s SG7 5BG. I R USER I * 1982 ZX81 MO NO P O LY allows up to six players to compete wi th the machi ne doi ng all the boring bits. Sorry NO cheati ng al l owed YOU can't argue wi th a computer% ZX81 MONOPOLY allows the game to be saved wi th a WI NNER SO FAR report to END all ar guments! Uses virtually an of 16k and comes compl ete wi th an i nstr ucti on bookl et 3 WAVES ELS OF PLAY 16%( RAM 7 LEV N E LASER SHI ELD +RAP I D FI RI NG + HI GH SCORE ARCADE ACTI ON GAME IN MACHI CODE SO FAST IT MAKE S YOUR EYES SORE' I GOOD ZX81 P RO G RAMS WANTEDI TRADERJAM Best de s c r i be d as a T R A D I N G A D V E N T U R E ga m e i fs a PAI N. Wr i tten for MASOCHI STS the game starts I NNOCENTLY wi th f40.000 in your hand THE N you'r e on YOUR OWN! You choose CREW. SHI P. STORES end CARGO. You even choose wher e to go and either make a FORTUNE or FAIL to SURVI VE. GO CAREFUL you have 200 Bytes loft fr om 16k WORK FORCE E The ultimate S SINCLAIR ZX 81 (16K) : DATABASE FILING SYSTEM 9 5 ( Dept SU C I 140 WILSIDEN AVE., LUTON, BEDS. Tel: Luton 454456 by D A LE HUBBARD Fed up w ith boring games — mak e y our ZX81 w or k f or y ou! The one y ou'v e been waiting for !! Cassette based Clear " me n u " operation Facilities inc lude sort, search, lis t, delete, change, total numeric fi eld, save and load fi le, line print, etc . Complete with demons tration fi le and full ins truc tion/applic ation leafl et. Requires 16K Ram pack. Applications: R e c ip e fi le Stamp/c oin collections Inventory Control Employee Data Record Collec tions Magazine article catalogue May be used for any applic ation where fas t access is required t o stored infor mation Access ac c epted ONLY £ 5 . 9 5 F ULLY IN C LU SIVE! Send cheque or P.O. or credit card number to: GEMIN I M A R K E TIN G LTD . Quay House, Qua y Road, N e w t o n A bbot, D e v on TQ1 2 2BU OR telephone us with your credit card order on Newton Abbot (0626) 62869 ok eO 0' N c, DESPATCH B Y RET URN O . ( ‘ 4 4 4 t • t o c 'v i t • 3 , Y 6 o't„ t ' 01 l l N1 e • oo/ s e e,4 t KEMPS TON MICRO ELECTRONICS PRESENT ITHE N G NEW ZX MAK KEYBOARD IF YOU ARE like many 2.X81 users and are fed up with the dead 'touch sensitive' key pad then consider the advantages of the new KE MP S TO N KLI K- KE Y BO ARD. Thi s is a ge nui ne p u s h b u t t o n k e y boa r d w hi c h h a s b e e n desi gned as an exact r epl acement, bei ng no larger than the existing key pad, but offer i ng all the advantages of a full size keyboard. Consi der these facts: • Fi ts on to the ZX81. • N o soldering needed on the assembled version (just pl ug in) • N o trailing wires. • N o special case required. •Posi ti ve feedback fr om keys. * Full t w o col our l egends supplied. •Ful l back-up service offer ed, i ncl udi ng fitti ng. This is a genui ne 40-key, push button keyboar d whi ch fits into the recess formed after peeling off the existing touch sensitive keypad. The kit comes wi th a precision drilled P. C. B. fini shed in man black, 40 keys, 2 col our l egends, connecti ng tails, adhesive pads and a full set of instructions. Vo w W m . • nd Ad d ' s. — 1, . / mnpl oon kl000 pm.= * m a w s z x a i k oote e r d CD Keybomid Alsembled 1121 es ast So b W O Also available from our range of products is a Parallel User I/O post E16.50 built Et tested. Gives 1 6 . 0 lines to drive light relays, motors etc_ Many already sold to education. Keyboard bleeper £8.95 built, repeat key kit E2.95. Ca • Te op U S . , l ot * W . , . 1 0 0 0 . ICIIMPROn M U M Electronics B OA ...n M o . . i e • • • • • • • m K e e e t4 . • Proprietor A. Pandaal. B.Sc., P.G. Cert. Ed MOVING AHEAD WITH ZX SOFTWARE ZX CHESS Et ADVENTURES PROGRAMS FOR THE /X8 1 .8 0 INCLUDiNG - ZX-FORTH 16K RAM PACKS 1K Z.X-CHESSII ZX CHESS I reduced to E6.50 ZX CHESS 11 now only E9.95 ADVENTURES ADVENTURE 'A' £6.00 ADVENTURE 'B' 0. 00 ADVENTURE 'C' E8.00 GALAXIANS E3.95 ZX BUG E7.00 Full implementation of FORTH for the ZX 1 0 — 26 erne faster than BASIC. 'Simplicity of BASIC with speed Et machine code.' EIVG BYTE RAM PACKS, no wobble problems. 1 year guarantee on each R AM PAC K. The best you can buy. Immediate de live ry. We didn't think it was possible, but the game plays against you, t w o ope ning move s. o n ly 1 K of me mory needed. Ve ry popula r ma chine code progra m, wit h six le ve ls of play a nd a n a na lysis option. Unbe a te n e xce pt by: A new improved version with a faster response tome, seven le ve ls o f pla y, a nd in a ddition a re comme nde d move option. Exciting machine code games with instant response, choose from the range below. You find yourself stranded on an alien planet. Can you reach your ship and escape In a jungle cle a ring yo u come a cross a n I nca te mple . You must bre a k in, colle ct tre a sure a nd e sca pe alive_ Be wa re . I nclude s a ca sse tte sa ve routine , you a re unfortuna te e nough t o be dra wn t o a n a lie n cruise r. C a n yo u re a ch t h e co n t ro l ro o m a n d tre e yourself or will the y ge t you first? include s a ca sse tte sa ve routine . Am the fe a ture s of the acarde ga me in a fa st ma chine code progra m. Sw o o p in g attackeas, e xplosions a nd personalised scoring A 3o in 1 machine code tool and cilisaembler, allows access to all registers and to search through, and modify me mory, w it h ca sse tte routine s. and many more. For a catalogue giving full details, please se nd a S, A.E to Artic Computing Dept. EE 396 James Reckitt Avenue Hull H1J8 WA. 44 is a stylish and ergonomic plinth for the DOA I t raises and tilts the TV to avoid eyestrain, holds the *KRA M in place and hides the wiring and power supply. This very professional unit costs LIS, a built-in power switch is t 3, plus postage at £1.50, inc VAT Peter Furlong Products,125Catford Hill. London SE6 4PR Callers by appointment, please.Tel 01690 7799. Visa , Access SINCLAIR USER July 1982 Accounting for small business TWO sophisticated a c counting programs ha v e been put on to the market by Hestacrest with the intention o f improving the efficiency of routine a c counting a llow cost. The programs are written for preparing accounts from incomplete records of a sole tr a de r a nd a limited company. They are written for use mainly by accountants but they can also be useful to the small tr a de r w i t h a l i t t l e knowledge of accounting. Figures can be entered into the accounts in the usual f or m s , inc luding cash payments a n d r e ceipts and bank payments and r e c e ipts . U s ing a system of coding, the accounts a r e then built-up from those, printing-out all the records of interest to the company. The programs are available from Hestacrest, PO Box 19, Leighton Buzzard, Bedfordshire. LU 7 ODG, costing E17.50 each or E25 for the two. Improved Othello MINE of Information has produced what it claims to be an improved version of its game Othello. The improvements include more features for a lower total price o f E6 .9 0 , be t t e r loading and easier use. All input is said to be crashproof a n d loa ding problems have been overcome b y a h a r d w a r e modification to generate a strong, c le a n, or igina l SINCLAIR USER J uly 1952 signal a nd tape duplication u s i n g a s i g n a l enhancement process. The n e w features i n clude the ability to replay moves a t any stage, both forward and backward. The n e w p r o g r a m , known as version 3.5, was shown at the ZX Microf air at the beginning of April and lost only one contest out of 30 when playing at half power. Othello i s a v a ila ble from Mine of Information, 1 F r a n c i s A v e nue , S t Albans, Hertfordshire. Adventures from Mgor ALGOR has produced two adventure games whic h are different f r om a ny thing else on the market. Shelob's L a i r i s a 1 3 K Basic a nd machine code game which gives a 31) image of your location and shows a l l t h e e x its i n perspective. There a r e ple nt y o f monsters a n d treasures, represented i n w o r d s rather than graphics, scattered a r o u n d t h e 1 8 0 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 whic h case a s e t o f tougher m ons te r s a n d more valuable treasures is generated. The othe r program is Mines a n d M ons t e r s , which allows up to four 4 players to play at the same time. It is a 13K Basic game in which all the locations, treasures a n d monsters are generated randomly at each turn. It is not very exciting but is entertaining enough and useful, i f only t o a v oid family arguments a bout who can use the ZX-81. Both pr ogr a m s c o s t E3.50, Shelob's Lair being packaged w i t h a n e c onomy simulation game and Mines and Monsters having a multi-player stock market game. Algor is at Dovercourt. S t . J a m e s Road, Northampton. Zuclunan for the ZX-81 WHAT IS said to be the first DC-81 version of the popular a r c a d e g a m e Puckman has been produced by DIL Software. Called Zuckman, i t runs on the ZX-81 with the 16K RAM pack. It is very user-friendly, giving complete instructions for playing. Written in machine code, it is a fast and interesting game and requires a quick appreciation of how to move the figure. Zuckman i s available from D J L Softwa r e , 9 Tweed Close, Swindon, Wiltshire. Parlez-vous le Basic? A C A S S E TTE t o h e l p children with GCE 0 level French examinations has been produced b y Rose Cassettes, w h i c h specialises in educational software f o r t he Z.X-81. For use with the 16K RAM pack, i t covers grammar 5 and vocabulary. O n t he first side, there are three sections d e a l i n g w i t h verbs, pronouns a nd adjectives, w i t h le s s ons followed b y tests. T h e second s ide de a ls w i t h vocabulary, w i t h 3 4 5 nouns, m or e t h a n 1 9 0 verbs and about 290 common expressions. The c a s s e t t e i s a v a ila ble f r o m R o s e Cassettes, 1 4 8 Widne y Lane, S o l i h u l l , W e s t Midlands at a cost of E4,50 including postage. Fighting the Prince aliens FOR THE intrepid fighter against a l l things a lie n. Astro-Invaders is the lead game in a pack available from joim Prince Software costing E3.65. According t o the company there is no superior version of the game on the market a t s uc h a competitive price. In machine code, it runs automatically on loading and involves 54 manoeuvring aliens which are knocked out by photonfiring torpedoes. A s t he game proceeds the attack rate increases. The other games in the pack a r e Gr a nd- P r ix , Penalty. Golf and Swat. John Prince Software is at 2 9 B r ook A v e nue , Le v e ns hulm e , M a n chester. MICROGENQUALITYPRODUCTS ZX81A/DCONVERTERBOARD DM This 4 channel analogue to digital converter. originally developed for joystick control, can be used for such applications as meas urement of voltage, t emperat ure, light intensity etc. The board fits in bet ween the RA M pack and the ZX8 1 ( N o skill is required to make this connection, and it actually improv es the stability of the RAM pack). Price now only 1 1 8 5 0 THIS SUBERB LOOKING DESK CONSOLE HOUSES A ZX81 THE ULTIMATE CONVERSION? JOYSTICKS for the ZX8 1 only £9.60 each • The most exciting add-on ever for the ZX81, free yourself of tha' dead. unresponsive keyboard. • 1 or 2 joysticks may be connected via our A / D board. • Turns your ZY8 1 int o a true programmable games mac hine • Extends the capability of the ZX 8 1 i ma g i n e the t remendous variety of games and applications that now bec ome possible • Det ails supplied on how to use the joysticks in your own programmes Please note that you cannot connect conventional analogue loysticks directly to the digital input ports found on most I / O boards, an A I D converter such as ours is required A free copy of ZX AMAZE plus any one of the games listed below when ordering a joystick and an A / D board. PROGRAMSAVAILABLE If you would like your ZX81 to look like this, then send it to us and we will return it to you built into this cabinet including a 9" monit or connected directly to the video output of the ZX8I, and a full mechanical key lock A l l for E195. Alternately we can supply the cabi net only for E38+ E5 P&P. ZX SPACE I NVADERS You'v e tried the rest. now try the BEST This program has many features including an ever increasing rate of play (they'll get you in the end) only E3.95 ZX BREAKOUT Quite simply the best breakout on the market. Features e n bat angles. (you won' t fi nd this one easy) Only [ 3 . 9 5 RI VERSI DE HOUSE, BRADLEY LANE. NEWTON ABBOT. DEVON, TELEPHONE NEWTON ABBOT (0626) 68622. ZX BOMBER. A very addictive arcade game. bomb and snoot your way out of trouble. ot herwis e you are doomed to crash Generat es a different pattern, f ord different game each time you play. On the reverse of the cassette is ZX REFLEX fi nd out how fast you really are. now only £3. 95 M U M M A ' The original and still the best. • Graphic display of t i e be . c omput ers • Board can be set up to any position. • Has ability toi rchange sides or level in mid-game. • PLUS • CHESS CLOCK on d reverse side, records time taken by each player. • Resetable • function. 8 • Single key entry. l now only f 6 50 e DISASSEMBLER Et MONITOR. Allows you to enter and run v • ULifr 5 n mac.birie code Relouat es to top of memory to allow you e !ol load other programs and find out how they work. Block move. Byte s search. Load display and alter all CPU registers. Wi n d o w on memory facility, uses standard mnemonic s , an absolute necessity .f olearning mac hine code f only E3. 95 p 7X CRA MB L E Th i s * the fastest arcade type game we k now l 32a zones t hrus t and altitude controls s mart bomb and fi ring ontrols y only E 3 95 . Wi• t o l i J O I L I MI NUL UI MI N e w f rom Mic ro Gen, Magic al Adv D ent ure Game wit h graphical position A l l o wi n g a host of options i 13 95 s Allp our games can be used wit h joysticks or keyboard. (except l chess and Sorcerer's Castle keyboard only) Supplied on cassette wit a h library case y It you writ e a program whic h is exceptional, please s ubmit it to us s will offer a royalty if it is suitable, We r Cheques + POs Pay able to MI CROG EN, 24 Agar Cres e Bracknell, Berks c Please add 40p P to all orders o r 46 d o f MICROWARE NEWSHOPIN LEICESTER FOR SINCLAIR cI 0 A COMPUTERS Keyboards • Ram Packs • 1 / 0 Parts • Monitors • Graphic Boards etc. Games, Serious, Home, Business Software, Books Et- Magazines. MICROWARE 131 MELTO N ROAD, LEICESTER Tel: 0533 681812 H oliday Clos ing S h o p Open Our shop will only 9 . 3 0 - 5 . 3 0 be open on Mondays, C l o s e d Thurs. Fridays and Saturdays S . A . E . Brings between 28th J une and C a t a l o g u e 16th J uly 0 A 'SUPER S U M M E R SALE NEW OR G ENUINE REDUCTIO NS' MICROWARE SI NCLAI R USER t i d y 1982 hardware world 11.111111 rcd), Kempston keyboard are available a t E14.95 each, including V A T and postage. DCP Microdevelopments, 2 Station Close, Lingwood, Norwich NR13 4AX. CAPITAL C OMPU TER S has pr oduced t h e fi r s t motherboard wit h ba nk switching inc or por a te d on-board. The expansion motherboard a ls o sorts out the reflections of the THURNELL ELECTRONICS ROM and RAM so that the full 56K left can be used. It has n o w e x te nde d i t s range of equipment for the includes a + 5V regulator ZX-81 to include a mother- for a s e pa r a te p o w e r board, L E D i n d i c a t o r supply, a n optional metal board, transistor dr iv e r case, and a range of plugboard, relay board to con- in boards. The boards contain 16K trol up to 1.5A AC or 24V DC at 3A. All are in cases of e x t r a m e m or y , f u l l but the original I10 port is RS232 serial interface to still available in kit form drive printers, Centronics and without a case. pa r a lle l int e r f a c e f o r A motherboard can con- printers complete w i t h nect up to four devices to handshaking, and a 2716 the port at once. The port ROM containing the driver routines. is based on a Z A ll t h e e x p a n s i o n motherboard sockets a r e BOA buffe r e d s o t h a t t h e P I O pulling-out of cards should not crash the system. The expansion motherboard costs E 4 0 . 2 0 , s e r i a l / parallel interface boa r d E45.95, 16K RAM 0 3 .9 3 , and t h e m e t a l chassis E19.50. All are obtainable from Capital Computers Ltd. 1 Branch Road, Park Street, St. Albans AL1 4RJ. Thurnell motherboard KEMPSTON Electronics mapped por ts a t 49148 has produced a m ic r o- and 49149. t h e various miniature version of the ROMs c o n t a i n i n g t h e ZX-81 keyboard with real words can be POKEd via keys. It is the same size as Basic to the loudspeaker the o r i g i n a l S i n c l a i r included inside the unit. The s pe e c h c a n b e keyboard a nd so can be he ard t h r o u g h t h e placed on the top of it. It is only half-an-inch high and loudspeaker o r , i f r e its black keys blend well quired, c a n be amplified with the ZX-81. via the jack socket providThe keyboard can be fit- ed — 8 ohms. The amount ted by opening the case of w o r d s i t c a n s a y and removing the original depends on the number of leads to the sockets on the ROMs fi t t e d ins ide t h e PCB and replacing it with box. A maximum of four the leads from the Kemp- can be fitted and the basic ston unit model is supplied with the The company also pro- first one. duces a n Educase which exposes the printed circuit board to the naked eye, for students a nd teachers to see t hr ough t h e c le a r plastic cover. It i s ideal f or demonstrating the working of a computer: t he back c a n contain a pa r a lle l por t complete wit h a demonstration program to run a Centronics printer. Unfortunately t he r e a r e n o Sinclair gr a phic s . T h e keyboard costs E22.50. Educes° E19.95, a nd the Kempston's new keyboard. parallel port E18.95. Most of the words are and so is completely comKempston Electronics is measurements of one kind patible with the ZX-01. It at 6 0 Adamson C our t , Hillgrounds Road, Kemp- or another, b u t PAUSE costs E14.95 as a kit withston, Bedford MK42 8QZ. statements b e t w e e n out a case and E17.95 fullywords can be altered so assembled with case. The that you can create your eight-transistor driver box own from the words sup- costs £9.95. a nd motherplied. You are limited to board E15.95. For orders DCP h a s p r o d u c e d a the beginning o f words, of less than E20. a dd 5 0 speech pack which can be however, as the speech is pence for post. Thurnell Electronics is fitted directly to the back stored only i n complete at 9 5 Liv e r pool R oa d, of a ZX-81 and which will words, not sounds. Cadishead, Ma nc he s te r not inte r fe r e w i t h a n y The speech pack costs planned expansion. Using E49.95, c om ple te w i t h M30 5 B G. Te l: 061-775 a maximum of two memory- ROM 1, and extra ROMs 4461. Speech pack from DCP I SI NCLAI R USER J u l y 1982 Printer interface Memory board from Fuller FULLER M i c r o Systems has added a new board to its r a nge o f equipment whch c a n fi t inside it s keyboard case. It starts as an or dina r y 1 8 K boa r d supplied w i t h t h e i n dustrial s ta nda r d 4 1 1 6 chips but i f y ou decide later that you need more memory you can upgrade the board to a full 64K by changing the R A M chips continued on page 4,1 t lir* , 47 419,- continued from page 47 and a fe w straps on the same board. The 16K PCB will fit into any motherboard whic h provides s oc k e t s f o r boards t o plug into a nd costs £39.95. To upgrade it to f u l l 6 4 K w i l l c os t another £45 f or instructions and the 64K chips to fit to the board. The c om ple te F u l l e r Micro Systems range can be seen a n d purchased from The Z X Computing Centre, Sweating Street, Liverpool 2. Mill, Frenches Road, Cam- program. A ll is contained in a metal box 61/2 x 21/2 bridge CB4 3NP. x 11/2in. which attaches to t h e ZX-81 e dge conne c tor v i a a r i b b o n cable t o prevent crashing t h e pr ogr a m , d u e TAURUS Computer Design to t he movement o f the has a 1 6 K R A M pa c k ZX-81. which also contains a 2K The 1 6 K R A M pa c k m onitor E P R O M f o r costs 0 9 . 9 5 w i t h t h e writing machine code pro- m onitor a n d £ 4 9 . 9 5 grams o n t he ZX-8 1 . I t without, from Taurus Comreplaces t h e t o p 2 K o f puter D e s ign, 4 7 H i g h RAM when the switch is Street, Baldock Harts SG7' thrown on the front of the 6BG. Tel: 0462-893900. 2K monitor EPROM TV Services bleeper TV SERVICES o f C a m bridge ha s a ne a t little keyboard bleeper caned the K A T keyboard audio tone. The device can be fitted inside the case in the space beneath t h e keyboard, o r i n a ny othe r place for that matter, as it is a n extremely fl a t PCB and piezo-electric loudspeaker. There a r e o n l y fi v e soldering connections t o make t o the ZX-81 PCB. as t h e r e s t i s r e a dy assembled. I f 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 when the computer answers; it also that a n y computer c a n grow from 1 8 K R A M 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 s ilv e r packs a r e connected mechanically as well as electrically, to each other, so there should be no chance of a faulty connection. The basic Persona module costs 0 0 .4 2 inc. VAT and postage. BASICare Microsystem Ltd, 5 Dryden Court, London SEll 4NH. Tel: 01-735 6408. Metrimpex disc drive METRIMPEX of Hungary is introducing a revolutionary n e w dis c dr iv e system to this country and at least one manufacturer. Macronics, has opted for it. The disc drive is very BASICare conversion 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 inserted BASICare ha s produced the O r g a n i c m ic r o, a system whic h makes i n compatability be t we e n systems out-of-date. T h e idea i s tha t every computer should use the same connections t o t he R A M packs a n d p o r t s b u t , because each time a computer manufacturer pr oduces a ne w machine i t changes the wa y i t connects, tha t has not been possible previously. Now BASICare will provide a personality module 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 supply is + 12V and + 5V and it weighs only 0,47 kilogrammes. The dr iv e provides a standard interface so that it can be used with disc c ontr olle r s a l r e a d y available. T h e pr ic e i n quantity is E50 and details can b e obt a ine d f r o m BATS-NC! L t d , 3 7 5 b Regents Park Road, Lon- The 1SK HAM pock from Taurus Comput er Design. RAM pack a nd you c a n enter t he machine code monitor by a simple USR command. The m onitor provides facilities s uc h a s h e x arithmetic, break points. copying d a t a f r om one place to another, decimal signals the start and finish to h e x conversion, fi l l . of a LOADing or SAVEing memory display, port read program. I t may also be and w r i t e , p l u s m a n y programmed to bleep in a more. T h e monitor w i l l program — for simulating write a suitable-length an explosion — by using a REM statement a t t h e PAUSE greater than 5. beginning of a program, so The KAT costs f 8.95 if that y our machine code you fi t i t yourself a n d routine c a n b e s tor e d E10.95 i f you send your there and will even re-set ZX-81 for it to be fitted. the Basic variables so that TV Services o f Cam- a R E T U R N f r o m t h e bridge L t d . Chesterton monitor will not crash the 48 standard connection, so to convert the ZX-81. BBC don N3 1DG. Tel: 01-349 computer or Apple in one 4511. SI NCLAI R USER J u l y 1982 ZX REGISTER brings together the Si ncl ai r ZX wor l d wi thi n 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 71 PUBLICATIONS References to reviews of ZX ware USER CLUBS w h e n and where to meet Much other useful information including details of other services and programs, notes for new users, advertisements. P r i c e £2. 95 f r om ..„ sft • Ots r i ti c . — — , ?only 1 l • 4 1 • MS NOW z B oth x I l A M pa c ts use same he/rt A B S plashe case 8 1S l re e h e d Wre n " o wn se n a co n n e ct o r to w h o o L p * om e c h a n i c a l sh e lsikt, I LIN... gua r a nte e d Foil., c opa loble we t, ZX P tinte i ci 5 er r i 01 the tNOTE 5 4561 K Sas R AM its usere addrassabse risereinty is in 4 areas 0 S in cla ir BASI C ROM ttreat only' 8•16k Machine code area unaffected by CLEAR. N EW. LOAD . SAVt R A IS321iM BASI C pmcparn area Al t i r , , e t• p e L e S W h e n c m . . . t e rm 19. d a Ohilk i BASI i fl C varLatiltis a rra ys and , d u o r - M o e I i m a m p e c SUPER IN e c a s s e t t e libit R AM naiededl r e o A n e nh.de lLe d ve rs• n n 0 1 o u t I tru SC Wo n g G A L A X Y I N V A D E R S lititit_ ifi t A r•.1 N o w t toLdrpotates imnpr tte e d inv a tie l * h a w s , a w n a t e d o n ; v e t o Ins titut lions a nti a leaguey tabtes ot the b r i g h te s t %rotes oblatneri n i s c h ot 3 rIttficuilly kneels GALAXY IaN VAD ER i S ca sse tte end instructions tmintrnum R A M I Still available at only 1 E 3 n n M achine c ode l o t 1U oettetulle iPvel%. 7 0 in vades .n 4 .ows, ut 5 o LYNCHMfOB I Fa mily Fun No .2) ca sse tte arid la st ructionstitik R AM I I S Acorripetthee m game lot 2 106 people The 1X81 picks turns. keeps the simme r tsu g h e i s Owe l o se rs e n u r n a l e d d ra p t u c l i G r e a t f u n E r k i r a h o n d l to e . FAMeILY 1111. R AM only 1 3 t FLINN* t Five !smoky IonwC • a S S e t t e and Manual na t. intiothuns• itstings. program n m g e si e J 101. Q t s -zx a u a l i t y Sortware— IS r 7 00 . \ St. : M ULTiGRAPHI CS 2 31101. R AM needed/ E S go : GRAPHI CS STARTER PAC K !Four lk Graphics':otter/1mM D I 50 \ a sa ta ing the use & PLOT, UNPLOT PRINT SPACE AT I NKEYS. the programs i n A bandits m e nu cltratn package of procerbutes geeing you fuN COn trOi 01 the D W I g rap h i t e . S u p p l e d o e th 7 LI u atj e i l l o sttstact m a n u a l Casseltr dil.1 12 page llama rater, bookial with itshogs, detailed ler beeral notes on G O M A. PEEK. The lX8 1 character tables etc STATISTICS PAC KAGE 1Forks lk Sta tistics proa re msl YOUNGS ZX REGISTER D I 00 LrsSettoi and 8 page booklet conleee.nci listings. instruc M uni for um , Sionsilte date 2 Woodl a nd Wa y , G os h° I d. Ha l s t e a d Essex C 0 9 1TH The register is bei ng cnnti nuousl y r evi sed ancl r e issued II you want your new pr oduct to be in the Register contact us We can also arrange for you to be on PRESTEL an d re su l l s C o m p e t e , Sme nd e a$ nC C s F o r fu r th e r de ta ils . P r i c e s a ll- inc lus iv e in B r a is e , Isles ESurDope a n c us tom e r s ple a s e a d d 30p pe r s o ftw a r e d e n t w u r l d e o r d e /OP - Overseas c uS tom e r s w o r e for de ta ils o f ha r dwa r e . entrants; c h a fe s , ' , , a r l d BRIDGE SOFTWARE ISLO r 36 FERKIWOOD. M AR N A BR I D GE. STOC KPOR T. C U ES SKS SBE , h t m aw c e , F r tile e n ti re ti e s w e k u t e d 4 . e q t i n i , e r e s s e e n o I r a r h i d i t e d on t h e s t i s n e g t c . o m p i r e P H a te a t W O A s e t o f otogr e dne r niti t o t u r n r a w , , S W I M . % ABt into a p o w * , tui ackKattowaO t e o i O A nd r o.a d e n t & f e n n e e d J o k n o w pr owe e nm ing N The m a t e c he e r I n s tr u c ti o n s e n d ; M i n t y o t l i p s ' e dv oc • D e ti g n a c i t o g o a r e n a d r i l l 4 w S 1 EDUCATIO NAL C O M P U T I N G ' k •••• s, CACt4 F L L . 3 F T W A L R i . r i r :i t• ::, • •• ••• • na l l ADV E NTURE SPECI ALI STS C2: VOLCANI C DUNG E O N/ HANG MAN E 4 . 5 0 Al V O LCANI C DUNGEON: Rescue it you can the Elfin Princess. Mythical monsters, pits, fiery caverns, diminishing strength and water make your quest anything but easy. FULL 18K PROGRAM * * SAVE GAME ROUTINE * * SI NG LE KEY ENTRY * 'Volcanic Dungeon is terrific value and I would recommend it to anyone'' M r s Thomas Cornwall BI HANG MAN: (Delux version of the classic game. Play against a n opponent or the computer's 400 word vocabulary. Good graphics. C3: ALI EN I NTRUDER/ HI EROGLYPHI CS M O O A) ALI E N INTRUDER: You awaken to find you ere the only survivor on the Explorer Class 3 Starship. Can you escape before you also fall victim to the Alien monstrosity that devoured the crew? There are many ways to end this adventure but only one way 10 survive! FULL 16K PROGRAM * I NTE RACTI V E GRAPHICS * * S AV E GAME ROUTINE * * BI HEIROGLYPHICS: Decode the ancient 39 symbol alphabet in time to save the famous explorer, M i l FULL l i e 18K PROGRAM * * ANI MATE D GRAPHIC DISPLAY * * RANDO M CODE * M a t US u rADV e E NTURE / MO V I E MO G UL E 5 , 0 0 Crt: WUMP m Al Wf U MrP U So ADVENTURE FOR 1 TO 4 PLAYERS. Seek the famous creature in t h e m o st da nge rous W u M o u s h u n t e ve r, A l l t h e u su a l a features s a arenthere:d SUPERBATS * P I TS * TREMO RS * S W AMP S * MAG I C ARROWS y PLUS Exciting new features EVIL GOBLINS that will try to sacrifice you g a v to the rWumpus. SERPENTS * WUMPUS MUCK * M AG I C SPRINGS * e * G I ANT . FULL 16K PROGRAM * * RANDO M Es PRESET CAVE PATTERNS YOU CONTROL THE LEVEL OF DIFFICULTY * * G RE AT FUN FOR YOU AND YOUR FRIENDS * B) MO V I E MOGUL: Guide your film through the often hilarious traumas of production. Use your budget wisely and you may make a fortune. Success depends on many factors and not iust luck. FULL 18K PROGRAM * ORDERS: Plus 50p P&P or large S.A.E. for list to,- CARNELL SOFTWARE 4 STAUNTON RO AD, SLOUGH, BEAKS. 5I -21NT The abova are also available Porn BUFFER MICROSHOP. STREATHAM . LONDON S1NCLAIRUSER l u l y 1982 B , r. _ P a c K RAM . -. h 1&2.- e i RAM 1 5k lilt 1 No Compcoeco itn offers so mucr for , so Ittlie BIG EDUCATORS 6 oc l i c e 1 0 Educare s 0 All pr ogr ammes ' fit 1K N Cr eati ve us e of e gr aphi cs o n Many i nnovati ve a i deas t Fully doc um e nt e d e M i ncl udes m a n y o games r Graph-plotter S Histogram n• Simon-spell • SktiLlit,uoid Includes TORTOI SE A simplof led version o f t he fam ous T u r t programme le CODED MI SSI LE Combines the fun o f a r c a de games w i t h hear ru n g E4.95 only p a p • Tunes-table • Sets Series-quiz • KY coordinates • Count • Equations • Areas • Guess a Voltam i Angles • U p s t a i r s n g Mastermind • +• 26Snake more E D U C A R E lemperature Cl od' shoot • lMoney D o w n s t a •i• rNumber s i • 1 V M1 7u; s i c EDUCARE .I I enclose cheque/ postal order foe f I n o t e s P N •I 139a Sl oane Stl 1 I g S11L S W P I X 9 4 V ei e *4o a n Lat ch a ts Immo 1.1 a a , ly S ie n a Atsee s,n a i s va st, m m ld , e n 49 s •,o e e Wn • n m 1 ZXEll SOFTWARE D V ) Gil e t i j A I L I C ALTERNATIVE PROGRAMS 11 16K1 FOR THE MORE DISCERNING ENTHUSIAST CASSETTE I , m , E , P a M AINS ONE A, irae mor m ath s so d tware w e d e ce le d re Knoichttre U p rag te rn t h e wo n * / O we ve nd che at T more than the beamg reply sorry you am wriying tr ,,gam' M A TH5ONE will girt your T A GREAT WGAME rined eiernts in th e th e me , e ne t an d . . . e l l e d n w yo u r ch ild We n n * T n t twt o N I I so m te e * h ake Ko h le min te d on the . . . a m m o l e s th e child wPote l do with pe n , and Dem O e tte h e s p o n e ,l IAINS KATE r i c o M s W N W . tn e e tse e te t co n re e ch th e p o ll N e i In tl h e INOWL m o v e e nd MOON See A Ntathsong • IklaitssAaae 1 3 95 l t CASSETTE 2 P LANGUAGE TRANS LATOR A He w n , / d o W, WI , i n id1 f o r e i g n l a i d R A N As. h oR rni GO , T slate tran g Ds wo n t, in se co n d . Ve e n**. t en ram . , b e ch an g e d an d S AV E D on E Neese Nos O w stale language r NInce 'N , i TEST n g r a i n WORD P o t T rn I I f s tle h le I NDF I D T EST wi l l we i r chdle te n p atu allt, v t i f . 'eae ry nD EnnnWeted twin are allowed and ine score out r,l ten RAM comas r FS aWind, S econd t answers Ire w o shown r , d I anwilata Translator • word r .0 1 3 P t dPiddictive FRO /klit T a m FUTURESOFT PENSHURST E S TATE . P RI NCE O F WAL E S ROAD. LONDON, N.W 6. TRADER 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 k now w ha t they have in m i n d . . . ? *Trader' is a new concept in D031 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 E10.50 inclusive. Send SAE for more details of Pixel games. PIXEL Pixel Pr oducti ons 3 9 Ri pl ey Gdns. London SIN14 81F. s I kito I RMO I M O G i Al t . E * 4 MS A111,14* t ' o r o rr CASSE rrt 3 o m RANK ACCOUNT 11E10 o w e t triri a aratemaini when yos can have roar own personal banking system itiVent kcsepts standing otdars I ft in,, iristiel OOP, and wall rell row when your balance in below ,t metre. banking lona then actually Thieve you lot ie J.*2 like the bank. Stereo/lipids ran e d b i t i Ca d a t e d e n d •4 3 1 D 1 5 0 . r O n n i n n i d r i n Ca . b e S H O W SOME S ILLS RE ADY RECKONER b y • I nt t o It n o w .1 winwar t ri e r ene.t... ' t e l e p h o n e / n e t o e t o re c o r r e c t Sank Around • Ready Reckoner 1 3 Yti a n PLEASE NOTE Du* software is at ins. VW, igne nt dui•SrIV and Wangs it, compare with I t&. wary bow how. the Sinctair stable and even I standard SM. s a y Nolinowledge .1C...t1i011n5 required lull load and ion' SO C . . . r o o m s W e x c e o d aAT I 30 AND IS DESPATCHED RV 12 30 THE SAME YOUR ORDER IS RECEIVED rP i s e r It N O T SATISFIED • 6 V I D N ' • t r ,, a M a k e chettues. c P U , e tc p a y o u t to l i r a l C n o i n s i s c i a 8 $ e ,CMEL,4110 IF tarraytv r , fi n * / I i i i i i 11111111 a WWWW W W I 1 1 1 1 1 1 1 1 1 1 1 1 (1 % _ g a. m e la * h i t t you play amp part i d a Football Manager roping with 4 lo• ' Aprobation 1 amid decisions ins ids ed in running y tour club. I here are so many 1 it la linpoaaible to Um them here but iacluded ire toren thy ' iniluera team 1 NORMAI.I.% mint. gismi.killings. %sage bilk to pay. and51111CMS / 'see 4 be saiii,ed! l i e'. a game requiring a great deal ut QOM. and peopk S i t tor Mersa!, hours on end 4 ue blase pr otir l. 1 play i ww, I l eser i F. ta, A R A N I M : that this is oue ot the best computer game", you'se ) t played! aNt I K t 1 O i t i t i l l i t 16• i i i i1i04 m I 11111111lI M t V I W i l l I 1 1 5 3 1 / A.t)ERAEL. •,f i t II H I ill • MAr s t At E R K E , 0.46 1 1 . t to Ottle t le nd Cheque HARDWARE REQIIIRE r S moth ?t r/11111/ h i , P potohle k 7 to. 41701C71111' l i t t TR.S80•• 1 ot 9 D e 6p t P . O . 8 0 . V M I Ii80 i s II ideo Genie 7 ,ti 1 CO. vintwitom RO M I I1 W i t TON PIC EVEN WA 14 7.%1 grr lea VW 1 MA 1 1: DMit R 81 1 P I I A V I .51 .411 m u m • I A m e r 1 : is l % i 1s ' I m F E • eu s N l L I At a r I I t et m A I i m e A Fo P ln ) Oe, I 1 RdT , h , Fdi k s • i i as l t e ( ! MI i e s , i e l %l / i I ng Ta n Cd ! hi *!Ogur case takes the ZX-81 printed board *Keyboard supplied fitted to case h . lo u r Ram Pack plugs into rear of case *Y *Assembled 4 yr Keyboard and case price 06.00 *Keyboard complete with ribbon cable & connectors . I * No soldering required ( ll *Large keys are used with changeable keymarkers *Keyboard ready assembled price E24,00 i o A ' N *Sinclair makes the best home computers and we make the best keyboards* . H U E ME N i i • Professional Grade Keyboard and Case at Unbeatable prices . 'Full pnont:v back guarantee if you are nal fully sat:sit *Priers tnetude VAT• *I6K Ram Pack — fully tested, ready built and in a case. eel Uses existing power supply. * S T A R BUY • E28.00 Ma i l Or der Addres s : l i G O RDO N E LE CTRO NI CS l u M s e a a k d e d l 1.50Ple.P. cheques pol o* to 76 Mountbatten Road, G O R D O N ELECTRONICS Braintree, Essex CM7 6TP. Telephone403760260-18. SINCLAIR USER l u l y 1982 50 SOUND with MC-81! THE EXPLORER'S G UI DE To The ZX81 The Book for the ZX81 Enthusiast. MAKE AMAZING SOUND EFFECTS WITH YOUR ZX-81 By Mik e Lord, 120 pages. Programs fo r I K RA M, and programs for 16K RA M. Games, Business and Engineering Applications. RAM Et I/0 Circuits. Useful ROM Routines. Hints and Tips. f4.95 £25.95 THE ZON X-81 ird PtirbiliVAr Wh at Can I Do wi th 1K? By Roger Valentine A freehand 0n9nài pook contairkng 40 programs and routines to ,me unexpended ZX81. 14 9/- The ZX80 M agi c Bo o k 'Wit h BK RUM, ZA81 Suppierne,•t • Mastering M achi ne Code on your ZX81 By To n i Baker 1 9 0 page, of i m , / ve n se w a l k o e ALL PRICES INCLUDE U .K. P b P ANC, t o 15% V A T W H E R E A P P L I C A B L E b e g m n e OVERSEAS CUSTOM ERS A D D E1 , CARRIAGE PER ORDER a n d PAYMENT WI TH ORDER PL EASE e x p e r TIMEDATA L I D De w S k e e k o w e d a l e Bataldon t Essex 5 5l1 5 5.IGi Te l: ioinsei 411125 /M ON FRB a k e f, S S I A M I ENHANCE YOUR SINCLAIR ZX81 1 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. N E W O YP Ein 5cl.) ORDERNOW! (VA TN .PL & A small printed circuit board tits 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 your name and address on back of your cheque or postal order and send to: D. FRITSCH, 6 Stanton Road, The/wall, Warrington WA4 2/-IS SINCLAIR USER J u l y 19412 • T h e ZON X-81 SOUND UNIT is completely self-contained and especially designed for use with the ZX-8I it Just plugs in no dismantling or soldering • N o power pack, batteries leads or other extras • M a n u a l Volume Control on panel a m p l e volume from built-in loudspeaker • S t a n d a rd 1X-81— 16K Rampack or printer con be plugged into ZON X-8I Sound Unit without aftecting normal 2x-81 operation • H u g e range ol possible Sounds for games or Music Helicopters Sci-fi Space Invaders. Explosions Gun-shots Plums Planes Lasers. Organs Belts tunes Chords etc c ' whatever you devise' • U s e s 3-channel sound chip giving programme control of pitch volume of tones and noise all with envelope control • E a s ily odded to existing games or programmes using a few simple eASiC lines FULL instructions with many examples of how to obtoin effects and the programmes. supplied Fully Guaranteed ZX81 PERSONAL BANKING SYSTEM with load/save datatiles at double speed Load the program in the normal way — enter, amend or delete your transactions (ZX81 will automatically scan standing order file and post any items due)— save the file of data onto cassette in 45 seconds — load a different clatafile into the same program, also in 45 seconds — enter items, etc. — save datafile only onto cassette (45 seconds) — repeat operation for any number of accounts. Absolutely no need to save pmgrani, as all information is held in datafiles. Very easy to use — unlike other bank accounts. Requires a minimum of I6K RAM can use much more (no modification required). On Demonstration at the next ZX Micro Fair. The Personal Banking System also includes the following features: Full page detailed Bank Account, dual display (or printout). Automatic generation of standing orders on due dates. Validation of all entries. Correct any ite m previously entered. (Single/Multiple fi eld correction.) Enter an item (previously omitted) in the correct date order of the account. Single key operation. Utilises a M/C keyboard scan. Search for any item or items by cheque number, description or amount — display (and printout if required) with totals. Continuous display of statement extract, continually updated during i n p u t of entry. File of standing order details can be displayed, printed, added to,. cancelled and amended_ Detailed User Manual. After sales maintenance. Send E9.95 ($2O) incl. fo r cassette and users manual to J.P. Gibbons A A R , 1 4 Avalon Road, Orpington. Ke n t 8 R6 9 AX, England_ (Send large S.A.E. for details.) There are only two suppliers of supported ZX81 software, this is one of them, Be sure to include your name and address. Co min g soon: Ba n k Reconciliation Module — a separate program on cassette that utilises data supplied by the main program (S.A.E. for full details). The only expandable system for the ZX81 The Personal Banking System is also available from the Buffer Shop, Streatham. London and Branches of the Computer Bookshop Group, full maintenance still available. 51 Two of the leading figures in the development of the Spectrum, Richard Altwasser and Steven Vickers, have cut their links with Sinclair a n d set u p their own company Secret plans laid by new company they had also been tempted by the Tiles, a software consultancy based near Cambridge, which had written money Clive Sinclair was making. Mtwasser 25, gained a degree in the ROM working memory for the engineering at Trinity College. Cam- ZX-81. bridge and went to work for a microHis first job was the adaptation of based a utom a tion c om pa ny i n 4K ZX-80 ROM to make an 8K ROM Worcester but found the organisa- for the ZX-81. H e also wrote the tion too limiting. After 113 months he manual for the ZJC-81 and went on to left and joined Sinclair Research in write most of the ROM for the SpecSeptember. 1980. trum, as well as assisting with the He did some work on the develop- manual. ment o f the ZX-81 a nd after its Both say that they found working launch in 1981 he was made res- for Sinclair very exciting — "proponsible f o r computer research, viding y o u c a n c ope w i t h t h e which involved him in the design of pressure without having a heart the hardware of the Spectrum. attack." The main difference they Altwasser has also been writing found between Sinclair Research software for the ZX-81 and his 'Cam- and other companies in electronics bridge Collection' has sold 30,000 was that "deadlines were very real copies. deadlines". Vickers says: "There i s a de fi nition o f a Before joining Sinclair he had a little knowledge of computing, own- deadline: that it is the date before ing a TRS-80 a nd having r un a which something should not be completed but that is not the case with Sinclair." Development of the Spectrum was typical of the way in which Sinclair Research works. A rough specification was worked-out with the main requirements, inc luding c olour . high-resolution graphics a n d im proved tape storage interface. That was set last September with now because their major project for course in teaching Basic. a final deadline of the Earl's Court the last nine months, the Spectrum, Vickers' knowledge, however, had ended and, like many other peo- was much less. "Two years ago I did Computer Show in April. By tha t ple, they wanted to be their own not even know what a ROM was," he time the Spectrum had to be ready to bosses. says. go into production, whic h meant "We had plenty of freedom workVickers, 2 9 , wa s also a t Cam- that not only had a ll the development work to be done a t Sinclair ing at Sinclair but at the end of the br idge , g a i n i n g a d e g r e e i n day the company was r un by one mathematics a t K ing' s C olle ge Research but also all the suppliers man and if a decision needed to be before doing his PhD at Leeds. In had to be chosen and the production made, there was one man who took 1980, after writing to a number of lines at Timex had to be tooled-up. That had to be done in conditions that decision." Altwasser says. computer companies, inc luding He and Vickers add, jokingly, that Sinclair, for a job, he joined Nine of great secrecy and very little inforthe development of the Z X T Spectrum have cut their links W with Sinclair Research t o set up O own company. their ORichard Mtwasser, who designed the F hardware, and Steven Vickers, who t wrote the programs f or the ROM h working memory, have formed Rainbow Computing Co. Apart from e publishing a book of programs for l Spectrum, the company plans the e a closely -guarded secret. are a"It is necessary for us to be very d cagey and apart from the one thing which w e ha v e announced, w e i would like to leave anything we are n doing secret until it is ready for g launching," says Altwasser. H e f adds, however, that something will i announced before the end of the be g year. uThey decided to make the move r e s i n 'We had plenty of freedom working at Sinclair but at the end of the day if a decision needed to be made there was one man who took that decision' 52 S I N C L A IR USER A d y I 982 Steven Vickers (left) ond I lic hard Alt was s er (right) in f ront of Trinit y College, Cambridge. mation le a k e d- out a b o u t t h e 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 o f working f o r Sinclair we r e tha t there wa s 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 we nt f or 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 SNCLAI R USER ! l i l y 1982 advise a b o u t something w h i c h would be better," say Mtwasser. For t h e f ut ur e , Vic k e r s a n d 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 suggestions for the ne w machine which they had liked, so had decided to use it. One of their major concerns is that they should be able to keep 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 o f c om put e r t e c h nologists w i l l fi n d inc r e a s e d pressure f r o m t oda y ' s s c hoolchildren. A lt wa s s e r s a y s t h a t teenagers a r e now a ble to grasp ideas with which he had difficulty less than three years ago. He adds that at the Earls Court Computer F a i r h e s a w s om e children w i t h leaflets a bout t he Spectrum. A s a joke he decided to a s k the m a bout i t a n d wa s told e nthus ia s tic a lly a bout i t s capabilities. 53 New lX81 Software from Sinclair. A whole new range of software for the Sinclair ZX81 Personal Computer is now available - direct from Sinclair. Produced by ICL and Psion, these really excellent cassettes cover games, education, and business/ household management. Some of the more elaborate programs can only be run on a ZX81 augmented by the ZX 16K RAM pack. (The description of each cassette makes it clear what hardware is required.) The RAM pack provides 16times more memory in one complete module, and simply plugs into the rear of a z x el. And the price has just been dramatically reduced to only E29.95. The Sinclair ZX Printer offer full alphanumencs and highly-sophisticated graphics. A special feature is COPY which prints out exactly what is on the whole TV screen without the need for further instructions. So now you can print out your results for a permanent record. The ZX Printer plugs into the rear of your ZX81. and you can connect a RAM pack as well, Games Cassette Gl: Super Programs 1 (ICL) Hardware required - ZX81. Price - E4.95. Programs - Invasion from 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 - ZX81. Price - E4,95, 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 - ZX81. Price - E4 95. Programs - Train Race Challenge. Secret Message. Mind that Meteor. Character Doodle. Currency Conversion. Description - Fives games plus currency conversion at will f o r example. dollars to pounds. Cassette G4: Super Programs 4 (ICL) Hardware required - ZX81_ Price - E4.95. 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 - ZX81 + 16K RAM. Price - E4.95. Programs - Martian Knock Out. Graffiti Find the Mate. Labyrinth. Drop a Brick. Continental. Description - Five games plus easy conversion between English and continental dress sizes_ Cassette GB: Super Programs 6 (ICL) Hardware required - ZX81+ 16K RAM. Price - E4.95. Programs - Galactic Invasion, Journey into Danger. Create. Nine Hole Golf. Solitaire. Daylight Robbery. Description - Six games making full use of the ZX81's moving graphics capability. Cassette G7: Super Programs 7 (ICL) Hardware required - ZX81. Pric e:- E4.95. Programs - Racetrack. Chase NIM. Tower of Hanoi. Docking the Spaceship. Golf Description - Six games including the fascinating Tower ofHanoi problem. Cassette G8: Super Programs 8 (ICL) Hardware required - ZX81-1- 16K RAM. Price - E4.95. 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: Biorhythms (ICL) Hardware required Z X8 1 + 16K RAM, Price - E6.95_ 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 - ZX81 + 16K RAM. Price - E5.95. Programs - Backgammon. Dice_ Description - A great program, using fast and effi cient machine code, with graphics board, rolling dice, and doubling dice. The dice program can be used for any dice game. Cassette G11: Chess (Psion) Hardware required - ZX81 + 16K RAM. Price - E6_95. Programs - Chess. Chess Clock. Description - Fast, effi cient machine code, a graphic display of the board and pieces, plus six levels of ability, combine to make this one of the best chess programs available. The Chess Clock program can be used at any time. Cassette G12: Fantasy Games (Psion) Hardware required - ZX81 (or ZX80 with 8K BASIC ROM) + 16K RAM. Price E 4 . 7 5 . 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 - ZX81+ 16K RAM. Price - E3.95. 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 ( Pao ) Hardware required - ZX81 + 16K RAM, Price - E 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 El: Fun to Learn series English Literature 1 (ICL) Hardware required - ZX81 + 16K RAM Price - E6.95 Programs - Novelists Authors. Description - Who wrote 'Robinson Crusoe'? Which novelist do you associate with Father Brown? Cassette E2: Fun to Learn series English Literature 2 (ICL) Hardware required - ZX81+ 16K RAM Price - E6.95. Programs - Poets, Playwrights. Modern Authors. Description - Who wrote 'Song of the Shirt'? Which playwright also played cricket for England? I. n) Cassette 133: VU-CALC (Psion) Hardware required - ZX81 + 16K RAM. Price - E7_95. Program - V U Description - Turns your ZX81 into an immensely powerful analysis chart. CALC. VU-CALC constructs, generates and calculates large tables for applications such as fi nancial analysis, budget sheets, and projections. Complete with full instructions. — .x• Cassette E3: Fun to Learn series - Geography 1 (ICL) Haraware required - ZX81 + 16K RAM. Price - E6.95. Programs - Towns in England and Wales. Countries and Capitals of Europe. Description - The computer shows you a map 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 - E6.95. Programs - Events in British History. British Monarchs. Description - From 1066 to 1981, fi nd out when important events occurred. Recognise monarchs in an identity parade. Cassette ES: Fun to Learn series Mathematics 1 (ICL) Hardware required - ZX81 + 16K RAM Price - E6,95. Programs - Addition/Subtraction. Multiplication/Division. Description - Questions and answers on basic mathematics at different levels of difficulty. Cassette E6: Fun to Learn series Music 1 (ICL) Hardware required Z X 8 1 + 16K RAM Price - E6.95. Programs - Composers. Musicians. Description - Which instrument does James Galway play? Who composed 'Peter Grimes'? Cassette El: Fun to Learn series Inventions 1 (ICL) Hardware required - ZX81 + 16K RAM Price - E6.95_ Programs — Inventions before 1850. Inventions since 1850. Description - Who invented television? What was the 'dangerous Lucifer'? Cassette E8: Fun to Learn series Spelling 1 (1CL) Hardware required - ZX81 + 16K RAM. Price E6 . 9 5 . Programs -Series Al -A15. Series B1-B15. Description - Listen to the word spoken on your tape recorder, then spell it out on your ZX81 300 words in total suitable for 6-11year olds. Business/household Cassette 81 : The Collectors Pack (1CL) Hardware required - ZX81 + 16K RAM. Price - E9.95_ Program - Collector's Pack, plus blank tape or side 2 for program/datastorage. Description - This comprehensive program 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 - E9,95. 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. p T o : S i n c l a i r R e s e a r c h , F R E E P O 1 S .T Cassette B4: VU-ALE (Psion) Hardware required - ZX81+ 16K RAM. Price - E7.95. Programs - VU-FILE. Examples. Description - A general-purpose information 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 call Camberley (0276) 66104 or 21282 during offi ce hours. Either way, please allow up to 28 days for delivery, and there's a 14-day money-back option o f course. ZX81 SOFTWARE Sinclair Research Ltd, Stanhope Road, Camberley. Surrey. GU15 3PS_ Tel! Camberley (0276) 66104 & 21282 Please send me the items I have indicated below. Ot y item Code price Total 30 L4 95 GI: Super Programs I 31 E4 95 62: Super P r o m s 2 32 E4.95 63: Super PrNrams 3 33 04: Super Programs 4 34 G5: Super Programs 5 35 436. Super Programs 6 36 GT Super Programs 7 37 GB: Super PriNrams 8 38 E6 95 69: Biorhythms 39 £5.95 GIO: Elaciammon 40 £6.95 GII• Chess 41 £4.75 312. Fantasy Games 613 Space Raiders &Bomber 42 £3.95 43 £5.95 614 Flight Simulation 44 t.6 95 El. English Literature Cassette Oty Cassette Code E2 English literature 2 E3: Geojiraphy I E4. History 1 E5 Mathematics 1 Ell Music I E7 inventions 1 ES Spelling 1 81 : Collector's Pack 82; Dub Record Controller 133' VU-CALC 84 • VU-FILE ZX 16K RAM pack ZX Printer 45 445 47 48 49 50 51 52 53 54 18 27 Post & packing only if ordering hardware 1 Item since Total £695- ' — L6 95 L6 95 £6.95 L6 95 C6 95 £695 t 9 95 L9 95 L7 95 L7 95 L29 95 L.59 95 E2.95 TOTAL it I enclose a cheque/postal order to Sinclair Research Ltd for E Please charge my •Access/Barclaycard/Trustcard no. •Piease delete as applicable. 1 , I I I I I I I 1 j [Mr/Mrs/Miss I [Address I I 1 1 1 1 1 1 1 1 1 1 1 1 1 1 [ 1 1 1 1 1 1 1 1 1 _ 1 _ 1 1 1 Peripheral difficulties 1 111 Andrew Hewson answers more of your problems, including some worries about the Spectrum and possible add-ons Andrew liews on of transferring da ta between I RETURN the knotty problem programs to but first I have some questions concerning peripherals. Peter Mann of Bedfordshire writes: I have been told that if I use my existing hi-li cassette deck on the new Spectrum, the computer would blow up. Why should that be so? I would m u c h r a t h e r u s e m y expensive deck than have to try a 'cheap' portable tape recorder. The Spectrum is a low-voltage device designed t o de te c t a n d decode t h e k i n d o f p o o r l y reproduced, low-v olta ge s igna l levels obtainable from the earpiece of a 'cheap* portable tape recorder. In c ontr a s t, a h i - fi system i s designed to deliver an accuratelyreproduced signal wit h sufficient power t o fi ll a room with sound. Large v olta ge fl uc tua tions a r e normal from a hi-fi system, even at low v o l u m e l e v e l s , a n d s o connecting a Spectrum t o 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 T V , cassette player, books, magazines, pe nc il a n d pa pe r t o 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 the printer suitable for printing ready-gummed Labels? a s k s J ohn M o d h a , o f Greenford, Midlesex. Unfortunately, the answer is no. 56 S I N The ZX printer is capable only of printing on the special aluminiumcoated paper supplied wit h it . I suggest you look at advertisements, as one or two firms supply a printer interface which allows the ZX-Bt to drive a conventional printer. Alan Pitcher of Jersey says: lhave just ordered a Spectrum. Can you suggest a cassette unit to use with it? Sinc la ir h a s i m p r o v e d t h e 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 i n tha t respect. Instead of recommending a cassette pla y e r which might not be available in vour writes: I would like to replace the TV I use with my ZX-81 by a small monitor t o obt a in be t t e r v ide o resolution. Can you advise me? I would not bother to use a video monitor. I have seen various TVs and monitors connected to ZX-Bis 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 c a u s e d b y t h e F A S T command. I shall probably be 1 ingictgod area, I suggest that you choose a shop which sells a variety of players and take your computer, your TV and a typical cassette a nd make sure y ou c a n LOA D a n d SA VE 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 t o Peter Stokes o f Great Missenden i s similar. H e letters advocating another make or model and so I repeat the advice to 'try before you buy'. Geoffrey Ottley is going to the States fo r three years and he asks: Will I be 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 2 4 0 V, 5 0 cycles p e r second. whereas in the U.S. the supply is at C L A I R USER July1982 glime 120V. 60 cycles per second. Hence a U.S. power supply w i l l be needed with an output of 9V DC and rated at 1.2 amps. It will also be necessary to use a TV made for the British market because U.K. TVs display 50 frames per se co n d , w h e r e a s U .S . T V s display 60 frames per second. The U.S. version o f the ZX-81 i s also rather better screened than the U.K. v e r s i o n . s o i f y o u r n e w neighbours c o m p l a i n o f i n t e r ference on their TV you will have to put yo u r computer i n a n earthed metal b o x . Perhaps i t w o u l d b e easier to buy a new ZX-81 on your arrival. Now I return to a topic which has aroused a good deal of interest since I mentioned i t t w o mo n th s a g o . Readers of the fi rst issue of Sinclair User will remember that I described two Basic routines for transferring data f r o m a p r o g r a m , a b o v e RAMTOP, loading a second p ro gram f r o m c a s s e tte a n d t h e n transferring th e data b a ck to th e rt Emr• 20 3e se 0 70 e0 • • • &i ' P 0 1 . 1 1 1 1 5 . - e 11, ,e 91i0-14 -PR - a 5120 130 T -c7 0 , RAC 1.5 • being o v e r - w r i t t e n , c o p y t h e program a r e a a b o v e R A M TOP ; LOAD th e d a ta fr o m ta p e i n th e usual way; create some space in the program area and copy the program from above RAMTOP into the newlycreated space in the program area. Obviously, to create some data to LOAD into a program we must RUN a previous program to read i n o r calculate the data to be SAVE. The earlier program could b e deleted line by line but the process is rather laborious, s o u se th i s technique instead: First note the line number of the fi rst line of the program. Suppose it is l i n e number 1 0 ; th e n fi n d th e effective length o f the program by entering PRINT PEEK 16396 + 256* PEEK 16397 — 16513. Suppose the result is 1859. Then enter POKE 16511, 1859 — 256* INT (1859/256); POKE 161512. IN T (1959/256); 10 or whatever was the fi rst line number. Do n o t a t t e m p t t o L I S T t h e fi lti 6 so NUM , . p cR eP i , r g t sI N . F 6 e 6 - FTf fi ll ri 132 ' ) 0 m T O . -.- ,SeT - - 6 0 ' a ' f . q 0 rr• . c 0 •••• +cI 0 , c,.3.34 140 6 0 -.1 1 ( 1 2 . 5 =-r l o0 3 e 0 a r e sa xz ,0 0f e variables o 1 z l -,0p. . ,t hi e s e c o n d p ro g ra m, t h uxs lr3e .a n,tatb l i n g t w o f v : another. programs to 'speak' to one I p0 1 1 I would like 1 Les Auckland writes: esC1. 4 l and LOAD p SAVE to know how to 1 tI- t data only into a program held in -,o core. Can you assist? 1 There are two methods. The fi rst 1_ -is quick and elegant 9 and consists essentially of writing - new SAVE and LOAD routines i n, machine code. The second method i s sl o w a n d A clumsy but i t is easy to understand and t h e n e ce ssa0ry s o ftw a r e i s mostly in Basic, so!Pwill explain it as the preferential method, The steps o in outline are: SAVE the data ofl interest on tape; to prevent the program in the ZX-81 t l SI NCLAI R USER J ul y_1982 s t t 1o f-Pt 1%1A. ' 06 0i 1 T - 1 0 3 1 - 1 • c i • ; s1-114 z " program b e tw e e n e n te r i n g t h e instructions or you will have to pull out the plug and start again. You are making the Z X whole program is one monster Basic line and if it attempts to LIST it all, i t 81 becomes confused. Entering 10, o r t h i n k whatever, deletes the monster line tin the h usual a tway. t Thehd a ta c a n th e n b e SAVEd, etogether w i th the display fi l e and other odds and ends, on tape. The second step is to LOAD a new p ro g ra m a n d s t o r e i t a b o v e RAMTOP. Th e technique i s v e r y similar t o s t o r i n g d a t a a b o v e RAMTOP w h i ch I have explained p re vi o u sl y. B e s u r e t o m o v e RAMTOP down a s explained o n 5 page 168 o f Z.X-81 Basic Programming b e fo r e L OAD i n g t h e n e w program. T h e fo l l o w i n g r o u ti n e copies a program above RAMTOP: 10 LET j = PEEK 16396 + 256*PEEK 16397 — 17509 20 PRINT 30 LET K = PEEK 16388 + 256*PEEK 16389 40 FOR I 0 to j — 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 d a ta ca n th e n b e LOADed from ta p e i n th e usual w a y. Th e current program will, of course, be over-written and so the fi nal step is to c o p y i t b a c k f r o m a b o v e RAMTOR A machine code routine is needed f o r th a t step, because space m u s t b e c r e a te d i n t h e program area in which to store the program using a routine in ROM. The routine is 20 bytes long and I suggest you store i t a t addresses 32748 t o 32767 b y entering a n d RUNning the following routine: 10 for I = 32748 to 32767 20 INPUT M 30 POKE I. M 40 PRINT I, PEEK I 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, 20 You 209, 42, 4, 64. 237, 176, 201. might l i k e t o determine h o w th e routine w o rks b y translating th e decimal n u m b e r s i n t o Z - 8 0 assembler using Appendix A of the ZX-81 Basic Programming manual. Before running the machine code routine, POKE the program Iength.J. into i t by entering POKE 32754, 1 — 256*INT (J1256) POKE 32755, INT (Ji256) Then delete the Basic routine, put the ZX-81 into FAST mode, and call the m a c h i n e c o d e r o u t i n e b y entering IF USE 32748 = 0 THEN STOP. Hewson Consultants 1962. •Please address problems und queries to Andrew Hewson. Helpline. Graham Close. Biewbury, Oxfordshire. 7 PERSONAL S OFTWARE SERVICES M A C H I N E CODE G A M E S THE M O ST EXCIT ING INT ERACT IVE M / C ACTIO N AVAIL ABL E BR EAKOU T PLUS 0 / 3 S U P E R BR E AKO U T Professional 4 0 key keyboard 1 6 k TWO DIFFERENT VERSIONS OF THE POPULAR ARCADE GAM E 25C0 BALL SPEEDS PLUS A CHOICE OF THE NUMBER OF BALLS IN PLAY M AST ER BREAKOUT AN D THEN GRADUATE TO SUPERBREAKOUT £495 PLUS HI RI SE 1 6 K I 0 / 4 S P A C E DEFENDER DEFEND YOUR MOTHER SHIP FROM THE AT TACKING FLEET OR TRY AN D SAVE THE POPULATI ON O F A LONDON TOWER BLOC K FR OM FALLI NG T O THEIR DEATHS L 1AS R EAR GUNNER OF A SPACE CRUISER YOU H AVE THE RESPONSIBILITY FOR /FIGHTING OFF ENEMY ATTACKERS 8 T IA 2 LA SUPERB FAST ACTI ON VERSION OF THE ARCADE GAM E INCLUDING ALL I TS /LFEATURES T H I S PROGRAM DEMONSTRATES JUST H OW GOOD MACHINE CODE 1 GCAN BE P U G N C N K ERACE THROUGH A GIANT M AZE 19 TIMES THE SIZE OF THE SCREENI PICKING UP POINTS AS YOUGO BUT WATCH OUT FOR THE OTHER CARS. ROCKS. OIL AND ICI M R WHICH CAN "KI LL" YOU' A REALLY SUPERB GAM E H I G H L Y RECOMMENDED 1 \ \ , ..A N 6 ...., 1 5 0 OR AN Y THREE K SPECIAL OFFER A N Y T WO PR OGR AM S FOR ONLY El 6 E FOR f 10 00 K 3 THE ABO V E PR OGR AM S AR E ON LY A SM AL L SELECTI ON FR OM OU R . WIDE R AN G E O F D u l l SOF T WAR E A L L O F WH I C H I s AVAI L ABL E 9 THROUGH THE Z A SOFTWARE LI BRARY S E N D SAE FOR FULL D ETAI LS. E4.95 12 /2 MAZEDRAGRACE 1 6 1 i 1 5 1 E 4 . 9 5 • All legends and graphics in 2 colours • No soldering to ZX81, lust plug in • Proper typewriter keys • RAM/Printer compatible. Kit E19_95 Built E24.95 Case E10.20 Repeat key add on TBA. 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 E2.95 Male connector E 1.25 Ribbon cable E1.40 per metre Mastering Machine code book E5.50 Programming for real applications E6.50 Tape for real applications E11.25 HARRIS St LOCKYER ASSOCIATES (Sole distributors for Redditch Electronics) Dept SU P r i c e s included VAT + p + p 33 Pedmore Close O v e r s e a s add E1.80 postage Woodrow South D e l i v e r y 3 days for in stock Redditch i t e m s else allow 28 days. Worcs. O f fi c i a l orders welcome Tel (0527) 24452 S e n d sae for free catalogue CHEQUE OR P 0 TO PSS, 112 OLIVER STREET C OVEN TR Y_ C V . SFE ZX81 Software Business Software 1 6 k & 32k FOR S MALL BUSI NESSES 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. P U R C H A S E LE DG E R. Keeps a complete record of all your receipts under 11 sub headings. The program will calculate Et deduct VAT. S ALE S LE DG E R. For all your invoices. The program will calculate VAT and list all outstanding invoices. All the programs will except entries up to 199999.99 Et will enable you to produce your accounts at the touch of a button. Programs can also be used if you are not registered for VAT. 16K programs accept up to 225 entries: 1 8 . 7 5 32K programs accept up to 675 entries:110_76 Special Packs including all 3 programs: 16K 125; 32K 130. V AT Et- PROFIT CALCULATOR: 1 . 3.50 Educational Software 1 6 k S P E LLBO UND. Spellbound game for 1-4 players_ Program will accept up to 600 words. Can also be used to test spelling. E4.75. T R A N S F O R M LTD. For details send S.A.E. to 41 Keats Ho.. Porchester Mead, Beckenham, Kent 01 658 1661. Callers welcome. 561Pae 58 ZX HARDWARE ZX Software SCREEN KIT I M O R E POWERTOYOURSCREEN in Basic programs BORDERS- anysize •anywhereonscreen I t tilt SCROLL- inALLFOURdirections 4Kto6411 FILLSCREEN any graphic or character ILIO III RCM CLEARandREVERSEPARTOFSCREEN- any part FLASHINGCURSOR- anywhereonscreen•simulatesINPUT withDATAFILES SAVEBASIC VAN IAB1 ES on casselle LOAD bKh into ANT drogran iB alDOUBLESPEED andMEMORY LEFT O M bytes otreacItime code ElvesIRSTANTAMOUSSCREEN RESPONSE •Becomes part of your Basicprialtram 1 1 0 CanMadded tousling program •H o need to toad separately SUPERBVALUE E 5 : 7 0 + P a - M C M A C H I N E CODEDE-BLIGIMONITOR Atlast.COMPLETEFREEDOMFROMBASICtormactoriecodeprogrammers •rematne va r • 16 m u t t * doomarudsIcr itICprogramming y codeandSaturgentry illComprehentrve Ron1.De bugcommandsincluding * Occupies Vif ARAM in Basicarea c RE o GIS m TE mRSiDISPLAY &BREAKPOINTS • S o p o l v e d cecassetteman 36 M e MinUat t & *SAVE, f o r LOAD.VERIFYATDOUBLESPEED from any part of RAM. H •Eadt machine e code mimes operating X1 n from Ram area alRAM ARto 6111 •M I N pone MX ologramsabove Basicarea • soort memory ID TIEEl nevermows ZX SPECTRUM H 1CON1AIRED M e w Ito the serious i n c VAT & P • P OSEL e piograrnate urina l be used with Basa Programs CAV t U n111Aversion of lt MCvalerian Mt SKIWAOADMRiFY bathes M I 16k to 64It tOEPITER, RUN DE BUGmackunecode in BasicREM lines a SPECTRUM o•CIpmalesfromabove RAMTOR J.41 • t0CompattAtiewith Basx •Soopted on cassette ette o 30 pa r rnanual IonONLY pAElot more detarls of sottudie inc VAT il•P+P S r CWO P i c t u r e scoue i n6CORKSCREW HILL. WEST WICKHAM, RENT BR4 BBB t Mal oats oats e , PULSE HATE COMPUIERMODEL r M o e f 1 4 o d a y r SI NCLAI R USER J ul y 1982 s n d e a e m E7.50 REM-LOAD MACHINE CODEENTRYIDE-BUG E6.95 .) Philip Joy considers a game of chess written for the 1K ZX-81 and finds it is very restricted Simple chess limits moves about Noughts and Crosses, I T have r e c e i v e d a l e t t e r o indicating th a t I made tw o stateD ments which contradict each other. I " I f yo u h a ve e v e r played a computer version o f th e game, i t S tends to be very easy to beat", was P the fi rst comment. E That statement refers to a version L of the game which contains no skill s all — just the rules to play the at o game. As you would agree, an unm interesting g a me w i t h l i ttl e s k i l l demanded. The second statement is: e c •'Gives you a chance to win now and o then, unlike many Noughts and Crosses w h i ch a re w h i ch a re unn beatable.. f u s i o n SI NCLAI R USER J u l y 1982 That one refers to what happens i f you insert a large amount of skill i t becomes u n b e a ta b l e a n d boring. I f , however, you have th e computer learn by your mistakes, as the a rti cl e w a s suggesting, i t w i l l become more diffi cult as you play. That w i l l give players a chance to win, p ro vi d i n g t h a t t h e p l a y e r a l w a ys p l a y s t o h i s n o r m a l standard. I w a s a l s o s e n t a 1 K ch e ss program in a neat package, w i th a cassette inlay created on the ZX-81 printer, w i th the instructions on it. The author is D Horne, Cowbridge, East Sussex. I have asked fo r some comments from two other people on the game and I thank Ia n Benyon and Leo Amatino for their help. There a r e some restrictions o n what th e game can do, because i t had t o b e fi tte d i n to 1 K . 'Mo se restrictions are no castling, no enpassant, and no pawn promote. The comment on those restrictions was that it spoiled the game. I shall stick out my neck and say w h a t I have always said — that the unexpanded ZX tive, except be used to control something. 81 c I must also say that a fte r I have seen t h e game, m y m i n d i s n o t a changed. The game is satisfactory nfor 1K but is nothing like what can nbe achieved on the ZX-81. o Amatino says he thinks i t plays tthe same game, a n d both h e a n d dBenyon say that it was a very short game. Horne says i t is the ultimate o for the atrue. 1K ZX-81: I suppose that is n y 5 t It is neatly packaged and costs E5. Amatino said that i t was not worth the money. I would say that i f you have a 1 K ZX-81, you could have some enjoyment from this inexpensive game. A Leicester reader sends details on the Arti c Computing ZXchess II. He includes a game which I shall try to include i n a fu tu r e issue. H i s comments are rather interesting, as they support my point about the end game. He says: "The end game is less positive". He says o f the save faci l i ty o f the game: " T h e m o s t s i g n i fi c a n t a d va n ta g e o f t h i s p a r t i c u l a r program is the save facility". A Cumbrian re a d e r has sent a game played against Sargon 2.5 and Zachess II. ZXchess won, He says that o n e b a d m o v e b y Sa rg o n clinched i t . T h a t i s interesting, because I have a version of Sargon on my Video Genie computer and I have found i t be be o f 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 c h e s s g a m e s w e r e i m plemented on such small computers; he must be surprised. I hope you can send me details of anything to do w i th chess o r mind games i n 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. 9 JRS SOFTWARE HAVE YOU HEARD A DUD BLEEP? 19 WAYSI DE AVENUE, W O RI NUNI , SUSSEX, O RM I O U TELEPHONE WO RTHI NG 66011 (Eesnialio and Weekends only) SWISS••,kra •••• •CP S o n . PIPI•cadla 1 . C . 1 1 . . A O • M il• a l • • “ •• „ * * * * * * * ONLY 18.95 INCL V AT + P &P READY ASSEMBLED Ion/off switch available at fl extra) Cheques & P,O's to: 1 1 3 L E _ g l ) FULCRUM P R O D U C T S . , Hillside, Steep Lane. Andon, W. Sussex BN14 OUF * F R r ia I6 O w ns •1 0 Mma i Pro, a dral • d a m or n u n r m t • • m * tgeol . I S= • • a tia a r t s t a t . los S WF . ras awe 1•60.p ••• r a ta I N S Isi S O W s e a m o • . I d o d 01.02 a. I , • • • • . o r e r w re a t i • a r e . . . . a m a a r t o a d . . 1 pd . r bonded u m , pa pra nl l a . 0 0 4 d • • • . . a n t i r O PF r a Prnp o w e • a r * . r o , Polol r • d r i p l • i . 1 a r n . • • • • • • I M M e . • Pol a r ra• •••• p m d ,, pa t •p o av nm TP. AP S 9I 0M1I N V I E aa t d m . i. m • n u n - NWT • dl a m • reapoot i• d'0 l u l p t ,0 . . 0 , ro •t • o I . 0• • • • .•tar a wtro .d n n e ot•L•• n o , ma UM lit• ro tte n * P U L A mildalidna ore r r a d . ro se ate o te g • o-p td . i t at. ...... , as • „ PiG •1 • • • tso t a • • • . . . w a r. . • t I SV a n d a n n 1 i m t p o m a n . a d • 0 1 0 A •1 el=21:1111 ' f t ... . . pl aaa I M P . , r m . . " . •• • • 1 1 . 4 1 •Pol or.di a a d d , • •a• • •m• e rd. t, e i . • pod O rd. . . • . 0 0 Pi m a IaaNCI N I NAO S I CS I NI US I N, ra & N M I • o t a t t i r s i l t t , t • • • • , GRAPHI CS TOOLKI T 72 e . r' tu l C M A C H I N E C O D E ro i n t WW1 , OP ate • vallallte l s r . • al Ondlell 10dr 1•• r r a d . ' a l mi a ra i n 10•11.0 d e l n a Nd I d e n n a d a. a Ma ad . .v. . . ••11,11,1 o d t ew d d . r • Si S a t d d l l t e ml 0 0r 0 . sa de * p m PM t •O M rde asn di t dl i d•ddr Pa c t drill do da l w ronte d o d l . 0 1 . . t a d r i s m a d O t e r e PO PP dra . O M ' PEO PO UPI O D CM O u r 0 12•000 a l ra mma a a 0 - p p . . W e n d W h d d a , o rd . u I'l d Pfl * 0, a d . d eL t o a n d •. l apl and A a n d ri r . 1 0 1 . 1 0 rhurp . .101 SUP. SL I M M S USSICISO ISa0 • • • • • a s s . i . e . O w eg b g s e l two e w e . wogf E t a .4 1 1 tan e s use s Mde a rra . t o . 1 0 . 0 d O d d l e a l r . w hom o r" e P P M * a t te aWs w a t t s G a t t . 1 0 1 . 1 . 1 1 1 1 1 0 0 0 . 0 . 0 , dodo veto N W Swe e ts o n tro atte woe s 60 s e so t ••• U ti l i ti e s inc lude • M inis tr y by te do‘plav and alter * Wo r d fi ll m em or y * * Register display and a l t . B l o c k copy * Generation of • REM staternein * Ta b u l a te d m em or y dis play w i th addresses • S hr wable visor Semen separate tr am m o n d e ; dis play screen * H e x to dec im al and dec im al l e Hee comvertrat * R outine to enable user to write hiS owe S ittirtiet in R A M Fec ildon to r an m ac hine c o d . and set br eak points A I m i n th e p a c k a g e rs t h e A n tyep e w7 7 3 2 4 K E P R OM t o giv e y ou th e a b i l i ty t o dev elop and save y o u , o w n per m am s w h i c h c an be i n s ta n tl y loaded T Aanent U prRogr U Com pr ehens iv e User M anual. P r i z e : E 3 0 . 0 0 S m a W O R O P R O C E . N O on ZX 8 I a n o th e r fa c i l i ty o f the 8 K E P ROM B oar d t l u n A aic E P R OM loaded w i th 2 c h a L L ,1 , i o ta e * S e t 1 L o w e r cafe charecterS c o * S e t 2 U p p e r and lower case c h a r a c tm d e * A b i l i ty to change c har ac ter shape o f any k ey D * Space in PROM tor 5 character sets I * Inverse of any character set still available S Pnce E I D . 0 0 A S M A CHINE S CODE M ON ITOR A N D TA URUS Send fo r details o r c heque E M DISASSEMBLER A N D CHA RA CTE R SET w i th or der t o 8 dPSOd•rd10111e on cassette with user manual at TAURUS COMPUTER OIFSIlera L ES 75p, C6 SCro and £6 50u , 47 High Street Baidock. E s p eRano c t i Pack v e l yWith TAURUS unique lay M Ce 16K Hertfordshire SC7 LIBC SaalChtable 2 K E P R O M lo ad e d wi t h e ith e r m ach i n e code monitor or available tor your own programs Price CaS CIO or 06.1:10 60 Telephone Baldock (0462)893900 by P AUL HOS M E S I Prl dt P . Mader. . . . r u t . . . And * se at . . . s e w s its sre . tat rost, ro t aw S . a . e . . o rto ttai S kate s NAPICa ASO . . . . . CE e arl e r r s rs. e rre . St • d a d . • rma d a rc e I t I S 1 0 1 . 1 1 . 5 t a d lipacatd e as war M A o w . . 1100A11 S e to • •Netios Si . . . re se t ite m. w t . dri onda uc u t i f t t IS m a m a . d ia ' S s t e a t . . tu ft,, m i t e rs t e t t h a W P M t a p , e • • s• e tis S a s s io ta GS A . . . C I pirtrran 0 . 0 1 0 0 . • r t a . watt SAM ,o ae t t ison i watt s m e a . w o w s . . I s ts • say total I S I A t t i C k tO Q 5 t.T aSe . I NS s • g cIe tin l e t u p , lam/ I S one • S t sg ataItiate TUOSlIP . . . t e r ! e te rs I S o f SASS w o e . . ddeddeatt Pa n Pl 'i l arradaatan r- ALL FC)R ONLY E5.95 ($11.91:1) TIP. I s e ag li • r o o m . • I . , " A s t a c t . a s b at, m a t t . . S 4 1 4 0 cre st s opg 0 a • f t . - o . t• M a t s , t t i s i s s s o r. , • , • _ • a c ra mpa ra ra dm 444 KIT E N DI N/I11EVOLUME! S r d o e r d 0 A o .. ; 1 , 6 4 , 0 1 1 . ,, g r . ; ••1 TO . CELEBRATION DINNERS 1 -- 50PAGES OF WORLDWIDE RECIPES Pr • f 4 . 9 9 laic P&P and VAT) 14 P SOPAGESEUROPEANRECIPES 6415 k w/ -__.•,_-_- Sp eci al p rice for two volumes ".----. 0 L 1-.- 1- ''', J C Mo re v o l u m e s t o f o l l o w f 4 Please specify . S 1 which vo lu me (s) _ Mail o rd e r o n ly U i 9E i 99 _II i P S e n d retity-mitta n ce ( i l i MICRO CO MP UTE R SO FTWARE ri i l P Unit De. P e r lindustrial Estate, Stockpor t Road, Lower Bredbury. cn Stockport 5 K6 21I P Tel: 061-494 2441 Pc hE &. a R SINCLAIR USER J uly 2982 PP t a& S II , 9 . V I Ure a rase aro ma at roe TAURUS COMPUTER DESIGN * , , o torat WS N u t . . e t oort slot is ye . St Q i n = ri a7 ar S ti te I S la s e g o s . . rag . . . it s e n a s t r a i t r a • MS SO S . . . . a t t . , . . . . t a &AT 0 1 2 t e 1 2 Si w s e e r s . . Cha l i k a l Ca r P1 O SC Pe t i d r o a ma d on , n e e .• ACCUS n IO d Up g b O S P O S S d I a . .• . a . . . St• r o w K M o a r. 0 . 0 . 0 1 Paladd a da ddrudna l a o • I ft. Sftft, g i n i s o . . . e O w Mr*Cl oi l ti a w k At a t i CL IM M O NSII * P a h a e l At . . . I N , tat. sormes e taar L IO WSSCNIII Jake SstiGal,kCISO, OOWN A l t a r s * . ASES PRINT tse tse or A L I A S . M O TO announc e thes e ti e . Al! l y dguaranteed , pfur l o u c t s 1 aeon 0 art th e C o m p u te r M i c r o f n i n As t h e d UR i UsS BcK EeP R OM U T I L I T I E S M OD U L E TA r n i n g 'er,ih EZP R OM y o u c an fo r g e t th e pr oblem s inv olv ed i n l o a d i n g th e Programs ar o u n t a n t l y av ailable a t s w i t c h X , M o d u l o r iotinn e a8tl y ins ide th e c om puter F ills m em or y istace b e tw e e n 8K a n d 1 6 K Runs h o r n c o mIp u te r power s u p p l y U A ty p e 2 7 3 2 4 K E P R OM loaded w i th th e b r i l l i a n t TA U R U S m ac hine s c outibties r' pac k age. ac c laim ed b y ex per ts as th e bes t av ailable M a c h i n e c o d , M O N I T O R c o n ta i n i n g 1 6 s o ftw a r e u ttl i ti e s to h e l p y o u dev elop and deb.., y our o w n pr ogr am s - lax RAM ON11%, 1 . 1 0 0 P 0 9 1 1 0 . CO RI CIROC 5 UP L i nI P•1•PCP r . . 1 • 1 G .611B 1.6 5 Anottlet inaererpiec• • 0 1 1 5.: 'SA / m arl s. . O. 1 Pi t a F•11. ' fl i t ma d a mp • rp a l d0 •1 1 9 al a m 1110 r d . l a rts . tl i t o T a rn c r . . . . . O rde a l on I S I V UI S E • 1 0 0 C dilda0 c a n a l . da P r t i • M N . . MO E Al so 01.10110 , A b a c k O S I S K C S S A I m o I te m M I , 'O W S ae S D C O l i a n t I s o 16K RAM PACK • * A P * * 0 . 0 . 1 * * * / * . * * * 4 1 1 0 • . . . . . i An e se e n n at m t g e . is rse t i t S am t Nr D The ZX81 Bleep 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 N o soldering required (no risk of damaging ZX81) Als o suits many full size keyboards Illustrated instructions supplied_ An ' 4 5 5 * 4 5 1 • 1 0 . 0 . . . . fi • A D D A NE W DI M E NS I ON TO YOUR KE Y BOARD • •-• •-••••••rp nilarir . 0 • a da d0 , 1 CO ,m1 ZX81 Sinclair 1 6 K ZX8 1 now at CambridgeComputer 1 Store! TASWORD • WORD PROCESSING ON THE ZX811 Your D u n bec omes a word processor wit h TA S WO RD Ty pe ir, letters, doc uments and pictures, s tore t hem on tape, and edit and update existing doc uments . Wit h a printer, wh ic h is not essential, you can print y our doc uments . TASWORD FEATURES INCLUDE • OVER 3 0 0 LINES of tex t in a tex t fi le. • CURSOR CONTROL and auto repeat on all keys, • SCROLL up and d o wn through the tex t fi le. • A UTO MA TI C word-wrap and right-jus tifi c ation. • FULL 2X131 c harac ter set inc luding inverse characters and - • INSERTION A ND DELETION of lines and characters, • A HELP PAGE onto the screen at the touc h of a key. • CENTRE tex t on the screen, and May a tex t lef t and right• REFORMING of edited tex t t o a neat lay out wit h a single ke yst ro ke TASWORD TUTOR E6.50 l o w - -- E69.95 E49.95 E 2 9 . 9 5 NE W PRI CE E 5 9 . 9 5 NE W PRI CE in our ' Bu d g e t Mic r os ' depar tment. M•11111111•1111• • • • • • • • • .111.1111E11111 fully inc lus iv e l - 4E> I > C ; ; ; . All units now in stock Wide range o f books, software and DCP packs also available We send y ou a manual and a cassette. One side c ontains TASWO RD The other side c ontains TASWO RD and TASWO RD TUTOR. This teaches y ou word processing us ing TASWORD. No programming k nowledge is required to usa TAS WORD. A cit o ? : - - _ _ L g a q & c ; • ZX81 Assembled ZXEll Kit 16K RAM Printer q ra p h ics s y m b o l s Mail order only - vmicrocomputer ' up to 14 days delivery, CambridgeComputerStore Please mak e c heques iP.0, pay able t o T ASMAN SO FTWARE 1Emmanuel Street, Cambridge CB1 1NE Phone (0223) 358264/65334 17 HARTLEY CRESCENT, LEEDS LS6 2LL Als o A c o rn A t om • VI C-20 • Tandy TRS-80 ZX81 H E W S O N C O N S U LTA N T S Z X 8 1 HINT S A N D T I P S F O R T H E ZX81 by Andrew Hewson £ 3 . 9 5 T i . . m o s t co te Die le p e e k e l O W p o . t a nd O o . . . . . . o t o otoolmoo• t o A. . • W O • W Ye Or M r DOotoolti No . 1E01 DO We n WIMAn wi 500. n v _ n fl . win to iwo We n wo o •, •S w & w im l S uoona o e nt . ou .m . p F o O n Gt L i t t i t . t o o d o m Eno 1 1 . 1 . • • • m i m e , • 00.00.0.1.to o . i e I P. M t in m a . . . . C u oO M O M M t o n . . c o m p r o n o n t r o u n •O n• M C O M '. I . K . .. ., . . a zt ax..4e "..ma c , DRSO PKKIr . 6 0 • 1 1 . • • On . . . a U M 011oomon L o n l e y t o t o . O . o . Ro m CO MM. woe twite itatooe rati• Moo Pe wit... Dodo M o w . . • rent M . , O t t o} O M s c o d e M. ha. , aw •,. . KO• M n no m aa e u ,t Wm. b a af t 1 1 ,g outEuE o . o 1 . 1 t 1 8 . 1 a . n t e.m o o n s p p o mp o m. out h OM L i n t o p i t t o i n 0 STA ToS TIC S ti c .• N In e .tRe w V n M rt oCtit oS.u Ir IAotOOT tO g Ib w e o t a . A o n e n c d o e ti w o d ti w r e A a E h o m a l m p t c o n i o m b n l e i n TO E 1 1 5 T VAL UE PO P M O N O I l k n NA M on thu r n d . i l c t o n o a c ow w w i t 2 mot'A d e e 6 , 1 4 1 l i n. g• . 1 3 Ow pol l si me M o t M. M o n . . . • 16K M EM O R Y £26.95 R LINE RENUMBER 64K M EM O PA C K E4.95 .; ' S o n . . 4 2 • k • I ' ••••voconi atitimage s toe g . C a R ,n A W. t i . .c w i .t . . . R e y Romany ploportom 'non V o w.* poet l e afl e t i t Awe dint w A a1. me 0 1 ( s 1 • S wwwe l l o tcie SEA o n e w l • L•etin • Ant to • o *14 o o t o f o , w o o w i lt o o w o o f t r " 4 W i t t . ' o w n t t , n o w o o p o o Lamegio CAA to o wl it E W Roict We . PRA Piwit• ''' 09.00 •6' ti ot l ut e I " Ho w COO t e t 48+8K N E W s a x ''S- o t o e t Ro o ✓ O W ' O m c a n t o . v. Mot a rm ut ROLM i re nel eni kgoettn , o t e T w EinVOOKIIII ', Wien c a p o n s C o o * . wood to A n R I M k u n t • by m o m M on ono n i ▪ K i• 3 1 ,n o t t . M E M 3 • 4 2•w1I RO 0 n 8 M . o 0 n1a .v e . . . . 4 • o -o o rv a N n o M• r-P e tn•. O ntol e ni kr n a l1 -3 w o n e ,0 • , • •••, -o & n .t• 0 P e c rM e ro ,a m *s iO h to e E i• tt -k n k n o C61 9 5 SI NCLAI R USER J ul y 1982 M a n w T o £ 6 . 5 0 l w . ' o I , I t * R o n . . . r e p t o o to ad OIl to a m o p. a . m. h u l l . . boyS "Nun. 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Op▪ M A W R Pi f rom tine 8 L w o w . N a . Loma t ot o progi mm f rom OP W t . L e t..fl . tood UWE Al WAI S E * w e t . , awe e e to M No h o w O • ye n oi spat,ost et ”LooLhot000no t me SO T°5 Rtn o rtAmt GO AD% o U. S. n at ' , t o w R o t motto. we t a s M itt RIM O RM IN ,• .L.O . AD ' • one SAW two . . 0 0 c 1 y a o . n . l t y s o S R w A l M e t • • • • • • . , l oom s * 1 .1 .5 . ow e 0 ' Wend 0 h* We n * W uwPorno R o a n . . . c r o o m e. 0 . 0 . 1 8 . 1 . A O . . co t W o ▪ E50niall90 ,n10 nnt•ty te l a n WWI I t e n , o i l l o2 0t d m i o n o g M t l i l t t i l t ' . 9 W Coati ea , .o• A',copoota e n k ▪ l wt Low" o L o . • • • Kd• Innen' t a l i . . • • • • ▪ n ivin wn l I ,o tive L 'wo ws 1 t e awe al R,owle rioRtmot t owe to o . o i r te ro l oI b . . . i t . . . o w e wec wh 0 N o' ,wt g o t ' t ono., tooth Goo0 1 E E5.95 * * N EW! o o W m M . o . tho m o n k . y o u oro d o . . . , • t o m . . 0 1 8 1 1 0 0 Mott. tO ommi ottutoos v e n d 4 1 y , nne n M , u m . t oo n o . a p r o • n M . P . t o . . • noon r m . . PILOT PRO G RAMMERS TOOLKIT n ' t h e r pont'og • home tnei Sot w• Am NEW! • 8 . . . MO . . . moo . . . NO M 1102 "STOP PRESS PLICKMAN £5.96" 2 O hot.. t o . v m . NM . m a n n . M t t O M M I O O 1 Y o u • , " ) 0 . p SENO A Al • 0 0 t o , . L A A LOOLI OP M IAO W ARE SO FTWARE b LATEST ' , AXES Cheque e to H E W S O N C ON S U LTA N TS _ D e m S U. BOA S t M ory•it tc h S o treel r d rd o i n g t o r d 0 . 3 n 0 ) ( 1 0 OIL p r o r q u o t e A r 61 Playing games with machine code examine h o w o u r s i m p l e I machine c ode r outine s c r oll N down can be used to good effect, to T produce a game simulation. We will H examine how a supporting program written in Basic can call the USR I routine to maximum effect and how S the F whole program can be built and tested stage b y stage. A logical I procedure to adopt at this stage is: NDecide t h e ga m e appearance, A strategy a nd rules. This must be considered L in the context of scroll down, a since we intend to use the routine we have developed. r Produce a series of statements t concerning the program fl ow a nd i operation. For a program as small asc this, a full-blown boxed chart is l considered unnecessary b y t h e e author. wUsing the statements, build-up the program piece by piece, testing as e you proceed for the desired effect. Soak test the entire program for several hour s , b y le t t ing y o u r fr ie nds , a c q u a i n t a n c e s a n d children loose on it. If there are any undiscovered bugs they will fi nd them. In the last of his three articles Mike Biddell looks at ways of using machine code in game simulation of the game plot. a comment and game re-start. It is war-time and you are flying a Add program t o advance t h e transporter a i r c r a f t t o l a n d taxing speed of the aircraft as it supplies behind enemy lines. As the proceeds. Fina lly , inc or por a te runway approaches, you can see program line s t o signify a win; that it is mined but it is too late at create a receding runway a nd a that stage t o pull up, since your airspeed i s t oo low. Y o u ha v e , Figure 2: VDU PI CTURE CREATED BY MAI N PROGRAM LOOP 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 t he statement portion o f our development pla n a nd 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. C a ll USR t o scroll tha t if *-Iiiiliatill0111 element downwards. Put the USR call i n a loop a n d t ha t should ump outside this loop to comment on produce a moving runway effect. the win and allow game re-start. Add the aircraft path by adding a Now let us make a start with the POKE statement into the loop. Allow main program loop. Delete lines 10, the aircraft to be steered left and 20, 30 and 40 of the scroll down test right by using inkey $ to modify the program and add lines 7. 10. 20 and Figure I : MAI N PROGRAM LOOP 50 as shown in figure one. Line 7 prints the game title on line 20 of the 1 PEPS E R N ) ? m; F A Z T . 1 . 5 7 f c L E screen; that is not scrolled, since RR F R 5 T 5 G N U P R / N T : ( T A N M M H M M M M M H H H M M t e i M M H M H H H H M H M M M our routine scrolls only 1 9 lines. IMMMMMMMMMMMMMMH MMMN MMPIMPIH MMMH MM Lines 10, 2 0 a nd 5 0 produce the F S * 4 MM P R I N T 3 L ET T =15514 approaching runway effect — study 7 P R I N T A T 20•9;” *ANNAMMWM** this three-line loop carefully. 1 0• • P R I N T A T 1 , 1 0 ; " Then r un the program and you 28 01 1L E T A = U 5 R T 50 GOTO 1 0 should see, if all is well, the runway approach. Press BREAK before the POKE address. Scroll down should runway reaches the bottom of the I have always had in the back of my m ind the thought tha t scroll create a p l o t o f t h e pr evious screen a nd you will have a VDU picture similar t o tha t shown i n down would produce a n excellent positions of the aircraft. Within the loop. POKE the mines figure two. Our main program loop moving roadway or airfield effect, so we will build the game around on t o t h e r unwa y , i n v a r y ing incorporating t h e machine c ode that idea. If you have other ideas for positions. Add the logic for a mine or works. Now a dd the aircraft path and applications of the routine, feel free verge collision. That should send the to pursue them. Here is my concept program pointer outside the loop for some means of steering it. I have 62 S ul y 1 9 8 2 I N C L A I R USER J Variable W i n line 5 defines the chosen a n asterisk (*CHRS(23)) to start address of the display file and represent the position of the craft at variable V i n l i n e 4 i s t h e d i sany time. Since we will be POKEing the asterisk into the display file we placement to be added, to position will have to locate it, as described the asterisk in the correct place on previously, b y PEEKing s y s te m the screen. The POKE statement in 40 places variables 16396 a n d 16397 a n d using those to define a variable W . the asterisk on the screen, directly Then add the following lines to the below the runway. The value o f V was determined by trial and error. developing program: The steering logic is in line 30. It 4 L ETV=4 1 1 uses inkey $ to decode keys 5 and 8 5 LET W = PEEK 16396 + 256* PEEK on the keyboard — the keys with the 16397 left and right arrows. That works on 30 LET V = V + (INKEY $ = "8 ")— the basis that i f irikey $ = "8 ", then (INKEY S = "5 ") the whole expression inkey $ = " 8 " 40 POKE W + V, 23 Figure 3: " RUNWAY ' — COMPLETE PROGRAM LI STI NG (Basic and Machi ne Code) 1 REH EERND)7 R R F° A S T 5 G N L P R I N T : 4 TAN HHHI v I HHmmHHHHHHHHHHMHHHHHHH .H H H ,H H HFH H0H H5H H7H M H H H M H M H H H M H H H H H H H H H 5M N $ 4" P R I N T 2 L E7T S =( 0 C 3 L E TLT = 1 6 5 1 4 4 LE T ) = 4 1 1 E LET U=P E E K 1 5 3 9 6 4 - 2 5 6 * P E E K 1 6397 6 CL5 7 PRI NT AT 2 0 , 9 ; ” * Aa nnt l a n* * " 10 P R I N T A T 1 , 1 0 ; " 21 01 1L1E T R• = U S R T 21 L E T R = I N T (5, -10) 22 I F 5 - R* 1 0 = 9 OR 5 - R+ 1 0 = 6 OR 5 -/ 3 3 ) + 9 9 , 5 2 30 L E T U = V 4 A * 3 5 I F P E E K ( U- I A. 1 ) =3 O R P E E K ( U + E EY N$ G = OTO 1 0 0 V ) =( 5I 2N KT H 1 40 POKE U4-V, 23 0 41 I F 5 - 1 0 0 THE N L E T V =1 . 6 = 41 2 I F 5 = I 5 0 T H E N L E T V = V - 3 3 4 -65 ) T - USER J uly 1982 SINCLAIlt H ( I N K E Y E 43 44 45 50 100 is g i ve n th e va l u e 1 (true). Th a t applies to inkey $ = " 5 " in the same way. Th u s, i f inkey $ = "8 ", th a t adds 1 to variable V and moves the screen POKE one position t o th e right; i f inkey $ = " 5 " i t is moved to the left. Then run the program with these additions a n d yo u c a n ste e r th e aircraft from left to right. Wi th its controlling logic, you ca n steer i t snywhere you like. including off the runway. We have covered items one and Iwo o f th e m a i n p ro g ra m specification 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 th e task, a completed program — i t is only one solution — is presented in figure three. Compare the additional lines t o th e rough program specification and you will begin t o u n d e r s t a n d h o w i t operates. To be frank, I have not yet managed to get the aircraft back off the runway. Is i t possible? Perhaps with more practice I might make a better pilot. In c o n c l u s i o n , i f y o u h a v e followed th e articles, you have a mini-machine code loader a n d a n understanding o f h o w t o w r i t e simple m a c h i n e c o d e a n d i n corporate them in a Basic program. It is not too soon to be thinking about your next machine code challenge. I F 5 = 2 0 0 THEN LET u = u - g s I F 5 = 2 5 0 THE N GOTO 2 5 0 LE T 5 = 5 4 1 GOTO 1 0 P O KE W4-V, 61 110 P R I N T A T 2 1 , 0; - - - A M A g N REPLAY Y / N ? " 4 1 2. 04 1 I N1P1U1T EY4$d R a n t a l l 1 3 0 I F Y $ = • Y " THE N RUN t1 I4 A 0 GOTO 1 2 0 250 P RI NT A T 1 , 1 0 “ 260 L E T U = V + ( I N K E y s = " 8 “ ) - fI NKEY $ = ( -* OR P E E K 270 I F PEEK (U4-V)=3 - ) =5 2 THE N GOTO 1 0 0 U 52 8 0 P O K E u - W , 2 3 - 290 L E T 5=54-1 3 0 0 I F 5 = 2 7 0 T H E N G O T O 41-00 310 LE T R=USR CT) 320 GOTO 2 5 0 RE 2 1 , 0 " 400 P RI NT A T PLAY Y / N ? " 410 I NP UT X $ RUN 420 I F X $ =• 4 3 0 G ) T O 4 1 0 . N' T H E N 63 competition 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 offer 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 listing. 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. mo.I• v o w aroma t o o m 0 . sonin ▪ m oo 6 . 1 1 . 1 115. Ny •••• r t"ENTICY 'FORM ▪ 0 1 0 . inino W i n o INFO O O P mom w o o N o w a glo. W o n 0 0 0 S oul sed as ........ ....... . . . ••••• • . . . . . . • ...... • Complete this slogan, which will be u a tie-brealc. I bought tn V(-81 because. • • • • • • • . . . • .. Natne . . . . . . . . . . . . . . . . . . . . . . . . . . . • . . . . . . . . . . . . . . . . . . . . . . . ••••1 1 ikddress . . . . . . . . . . . . . . . . . . . . . . . . . . • . . . . . . . . . . . . . . . . . . . . . . . • . . . . . . . . . . . . . . . . . . • • • . . . . . . . . • • • • • • • • . . . . . . . . . . . . . . . . . . a• • It Send sour entries to BCC publications, 30-31 Islington Green, LOnd011 1 1 8 1 3 1 to arrive not later than luls 12. 64 vow , •• •• • • • • M O. I n.. I t SINCLAIR USER l u l y 1982 ok,r ZX81 SOFTWARE AL T ER N AT I VE P R O G R AM S 1 ! b i t ) FOR T H E M O R E D I SC ER N I N G EN T H U SI AST ! ca•85ETTE I M A T H S O N E 1 1 5 KI AT T ENT IO N AL I P ARE NT S ,e we . . 'P, r o a r g a t e d .,t e . sp rete enoth e n ame s' wa y an d 4 . . 1 " ; g u m e mu. L h ad wh e re b e / she he e p(tme Lbad ie m wro n g N on w th e . . . N e e se . tb pre me d on th e scre e n p m tw the che d * mo ld rk, wi l y pee e an P. dr...De a ec l o c o v le C AS a SnAIL t I aS Ku I n e MAT a o g f M ,a1 1 ,,,aate , can m o th th e poe t fire r h at th e ' u rn s b e co me mo te e nd min e C t w l e d•dickhn • kiodenelere • le tate skate 1 ao r m m 3 9 5 i t Ile M a te lC twA S E E er r ' 2 m o Le A N GU A GE T R A N S L A T O R .d 41 ae atatio ti h o isan , rn 5 0 0 * co d s y e t o e v n Wo rd s bem re e d ,t I e ; hange d an d S AV E D tee .;e a d . P . a . * Hat 1 V a We b r,d W WORD TEST *giFor aO g we ve rtWfl . 0 r trie e lb e e t o f th e fam i l y W O R D T EST wi l l g o t ch ild re n p arb o il. aH 1 n d , S e co n d t ry , C r. alln yae d an d true ao o rn o u t o f ran wi t h ;.ompe e te d we gtAna ane rs e re Ish u ato nt t Lampoeue I• e e alato t w a r d Te al 1 ao l 3 R S lp f m aCAS S E T T E w 3 te g SANK ACCOUNT l Yl n it I t ae t f o r j state me n t W. ri n yo u can h alm yo u r O wn p an io n al b an kin g Ende r ic rho Accehoe ptsIR ba iO W y lw s u e th r,m a d n o lnc ebanking isholt,a • • Cow thee. actually charge you tow.!' Jul re sh I, . .l be e kde Ord an deup tobISOe tran i k e t n sacti . ' o n s can b y • h wo rt' ea S t aBILLS HOME t t e READY r n . RE d CKONE e R np r We al lo kn o w if yo u r in e tn rCitYitale p h o n e /n e t p ly are co rre ct • o•r T Se rb ACco tin t • F laath r Illach ame r 1 3 0 5 vo h ogPt EASE NO T a E O u r t o t t . a re is of the ye ir, h ig h e st * Jah rfli an d are n as to ourneabie With r w 11,11 ye n ( be ent h e re th e S in clair %taig a * M I e n tin a t sav so oronierwtha **Caged% t h i r aastao d e rd I rm n of coe nputtng te th e re d P al k. . . l e n d run' No a nowe e dga e; t iYOUR ORDER w s IS RECEIVED AT 1110 AND IS DESPATCHED MY 12 30 THE SAME h rDAY 1 4 O A O T M ONE Y S A C K E L, . • • • • LI T r - 5 M ON TH oaREPLACEMENT GUARANTEE v nt a gt cheques. F 0 pe tc payable to tr r ro o yu g or r r p a .i m .d l ,g o lM t e A s Te o y H u o S . u O E r N a Ed s u w t ie w lt o l r g d m t . o a r p t e a , i r a t g FUTURESOFT 38 PENSHURST E S TATE . P RI NCE O F WAL E S ROAD, LONDON, N W S. TRADER It is hard enough to look a t an amorphous hydrosilicon blob from Psi, never mind swing a deal with one. But when they ask to pick your brains, do you really k now wha t they have in mind ' Trader i s a n e w c onc ept in ZX81 games . I t is a graphic adventure so big that it fills your 16K Barn 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 f 10.50 inclusive. Send SAE for more details of Pixel games. PIXEL Pixel Pr oducti ons 3 9 Ri pl ey Gdns. London 5W14 81-IF. SI NCLAI R USER i u l y 1982 Er'sEP) la 'V IF t a l l ! E l M a g l ot a / %So T a m: e s TRAM° 11;11 () (,1 i t W AGAME4,71cIdictive GREAT FRO M I \ 1 ,SE.-1.caN.S• t , . * 4 M I iSiOdNS* L 1 . 1 d ' q N R N az stam IIIN M 1 1 . . 014111,,Wrim .: 1 AINN R A r ilit dK I M fin r i m AHEM 1 1 * 41 • * -1 ( .7 ' * P I CK )()1•1? A sN1FO: R i 4-1(11 At - I TC1 1 * I . 1 E i l i i i itloYMi i i i i i 11111111U M I I I i t L n , 1his is O i a mere simulehiufi. M I thi4s is an e‘citing and highl, eakto,able game in * M e t loon phi, M the part tot a ootba l l **answer roping %sigh the X°Pied in ru.nint s problems and decisions ins A lertiores u e r ci i lisuimpossible b 1so 1 list them herr bui included are form sloop reain 'S(101111MAIII %in). T giant-killings.. wage bilk to pa,. and , •PU out Ie%en mbe sacked r e I * is aa game e 1r requiring a great deal of skiti, and people pia, end toe hike pr . , 1!), s il tor o literati, hours,=om 1 E G E ARAV E E F !bat ibis is one tot the besi compeller games soon's, m a n , e . HI 1 111% AIRE, this game is estremel, midirtise! , 1 1 1 1 1 1 1 1 T1 1 1 1 1 1 1 o V P h i 11 I ' V s i N ( ( Fr L L MANAG E. R P, t N t E P IC S 1111 I k H k I i n A k IS To Order k•esti Cheque. P <1. E 7 HARDWARE r REQUIRED i metly ha whir A m m c r t v t : C A W ! . /IOW T R A M P 1 Depf P . O . . A O N 170 ZUG t ideal Genie CONNIA4•1111011C RA RO M L E V E L I11 M i t l a % N E E IV M WA 14 7,%t. 1•11 MA R 4,1i 1 6 / ‘ RAM [ OOTBA 1 ,1 1V 1 4 I F ( = =• • M M . E NO ( M P ( ' 1 k Professional Grade Keyboard and Case at Unbeatable prices *O ur case takes the ZX-81 printed board *Keyboard supplied fitted to case *Your Ram Pack plugs into rear of case *Assembled Keyboard and case price E36.00 *Keyboard complete with ribbon cable & connectors * No soldering required *Large keys are used with changeable keymarkers *Keyboard ready assembled price E24.00 • Sinclair makes the best home computers and we make the best keyboards* 'Fun money back guarrotle( iF you arc not fully sattsfeed 'hires twig& VAT* *16K Ram Pack — fully tested, ready built and in a case Uses existing power supply. alisTAR BUY - E28.00 Mail Order Address: P l e a s a m i t t 5 0 P&P GORDON ELECTRONICS M a k e E'NCOWtISayablehp 76 Mountbatten Road. G o R D a v E l y c r i e o m t • . c Braintree, Essex CM7 6TP. Telephone I0376) 2 6 1 ) , I M. 65 SPEC T R U M — ZX81 BUSINESS GAMES EDUCATI ONAL SOFTWAR E EXII, e75K.1 G.C .E. programs Grammar plus 3 116k1 programs 0 Vocabulary G.0 E " 0 " LEVEL M AT H S: I 116k1 leach and L Etest program plus 2 110k I programs ol generated quesimns Irom • ' V E 0(web L explanations', e v e l L EDUCATI ONAL QU I Z . 4 1 1 sF General y l l a Knowledge, b u s on English 6 K! R p r o g r a m Reasoning s and All questions use RND function. E Maths. N JUNIOR EN GLI SH 1 18 13 years! M e a n. C 1. HMeanings 2 (Nader'. Peas of Speech, wigs Proverbs. Simile s. Anagrams. , JUNIOR ENGLI SH 2: kliorns, Opposites 1, 3 Opposites 3 ha rde r/ Gro u p Terms, Od d i Word Out, Spellings E4 1 50 per cassette or send sae for catalogue to, R O SE C ASSETTES, 148 Widney Lane, 6obhull S W e s t M idta nds 1391 3 1 H K 1 21011 D A T A B A N K I E K Serious Progra ms from SANDERSON SOFTWARE • 3 programs on one tape • Create your own &avow • Vocabulary Keyword feature • Add, Sort, Search, Delete your own Databank • Change Data hv Cursor Select Many Se rous Use s Job? Work Programming M u'Toole Inde xing Disco, M usic Libra ry e t c IS Owl. p & p a nd d o c u m e n ta ti o n P 0 o r C he que s to Sanderson. 1 M a nor Court. Breaston, D ER BY DE 7 3 AW A ST R O I N V A D E R S 116K) •••• Z X8 0 4 X8 1 SOFTWAR E • ••• ZX Adve nture Tape 1 M O O Greed., G u l c h P ha r a OhS T o m b , M a g n M ounta in - 1 6 K R A M r e quir e d The N owotnik Po ttle b Other Drue ruoris C 5 0 0 Three Or igin al pr ogr a m s to p mturiater u I nclude s a f a st inte ra ctive z z le a game n d 1 6 k R AM demoldron EXI ll Pocke t Book E 5 95 35o9 o r progra ms. a rt icle s u se f u l s ubr outine ." p l u s c r e a te V O , , dventures' A Atom Busine ss C 5 95 Twelve progra ms f o r t h e est:tended Acorn At o m - sa le s gra ph. nomina l ledger Plus much more ZX81 Pocke t Book Cassette t S 0 0 Atom Busine ss Cassette ( 8 6 2 Mail order Phipps Associa te s Moe Order Dept F 99 East Street Epsom Surre y k i t 7 1 EA Phone Acce ss/ Ba rcla yca rd orders Epsom 103727121 2 I 5 M ANSFIELD COM PUTERS Er ELECTRONICS 79 Ra [coolie sa te Mansfield Notts NO 1 8 1 )8 Phone 106231 31202 Stockists of GENIE. ATOM . VIC 20, 1X81 Plu s large range ot software, accessories b books SPECIAL OFFER M t PRINTER PAPER. TOP QUALITY 5 rolls for only 110.95 VAT. plso "EEBEE" "AT LAST", a serious mone y m a kin g p ro g ra m with sel f check a n d tile storage. 4K. COM. "SAILING", l i ght winds, currents, haz ards, adj ust sails and rudder t o reach har bour b e f o r e s t or m breaks al ( 13.96. 66 For n r 8 l i S o e c t r u m . Quality tapes, error tree. Cheque, P.O. to "EEBEF Wonstree Basildon E 20 asses S5131PG. E B E E . Superior ma chine code progra mmiriu last a ct io n sp a ce gra phics, a r y . , drmension inZX-2 I va lue • e xplosive on-screen kill effect • high-scoring saucers • 5 4 attacking aliens • •fe de ra ting attack rate • clestructahre defence shie lds • Cd e fo rl u O u S S t o re an d h i g h • sco re On ca sse t t e w ir t h f o u r B O N U S games. A R C A D E G R A N D PR I X (ma chine c o d e s k i l l , 4 l e v e l s i PEN ALTY lge t re a dy for Spa in 1321. GOLF b u d g e sh o t ste ngth. a n g le s. bunkers a n d ma ybe hole I n one (' plus fun SWAT 5 games on onecassette for only E3 6 5 ipear h e e l O r d e r n o w f ro m Jo h n Prince, 2 9 B r o o k A v e n u e leuenshuirne M a nche ste r M I 9 Z3181 SO F T WARE DAT ABAS E A rn at •nttot e t n • . n a a, t T • lat O t an T d e e • • PWs' ,Je C o nrt r o l n r 0 e rni n, 1 0 •9•1 . • m c o r c h , e n d m o r e F e a t u r a s s.nchade u , turptd ate p ri A I. Atm , co u n t_ t e , f hr adi de. ds ei ler te s•awe. ato t r eon d ta,h c A hk r, l o ck S u p p l e d cu d d, .,,,n -lanM te h ol ne e' n d t a n co n te wto n q t wo m e re . . . d e l •I . E . E s c e I . v t vataa•1 , O I l S r to , 0u005tiA0DRESS-9001C BUDGET hill record ma y ou' wiceenereseem hrLi 1 A 0 DDRE S S 0 0 K , D i a l e natothrta r, u n n i t aanadt te s .to n o h e code dot ratt * c o n Oa th 0 • 0 0 ...r . Ice only £4 • k 1 4 1 o Ed u catio n al o ' t o ro o , ye s at• e italwa. le tch td In s r SODA DST O RB. CRO Z P ACK, F U N C T I O N P L O T . n a r n e a STATISTICS t . e San d S AE to r tai l * M i n h tal In th e onsd o th e r o r wow?, tarn to o P U R V ES f 12 Sto b h n i Ro ad . Go re h e odtp, w a d E f e i rs. , 1 c 1 e 2 b 3 u d * g 5 e _ t h e n t 2X81 CO MP UTE R + 16K RAM in superb condition, all yours for only E100 o. n. o. P hone 01-462 1614 after 5pm. 7X81 1 6 K " RE NUMBE R" . Re number your pr ogr am lines, i ncluding GOTO's and GOSUB's, using thi s gener al pur pose uti l i ty routine. Recor ded twice on hi gh quality T D K A D C46 cassette. 0 . 5 0 all inclusive. M. R. Irving, 22 Wheatley Way, Chalfont St Peter, Bucks SL9OJE, AUTOCHEF As M D you must negotiate for leases. decide on rrtenti prices, level 01 wages, a dve rtising e nd divide nds a nd forecast le ve ls of inflation. I t you are nol successful you wet be nsecie to resign! AIRLINE You must decide on number of aircraft to operate. kWh and fuel contracts, whether t o buy to charier, a nd levels of staffi ng and maintenance P lease s pe c ify c om pute , whe n or de nity . Each p r o g r a m m a k e s u s e o r H I STOGR AM S and BAR C H AR TS and uses 15K f 4 . /5 each or EB 00 fra two C.C.S. 14 La ngton Wa y , London SE3 ITL Tel 01-859 0763 ZUCKMAN (16K) The first ZX81 version of Puckman * A i l Machi ne — code * Trail, Energy Posts etc. * On-screen score, hi gh score * Authenti c action only (5.95 inc. P&P Send cheque or P.O. to: WANTE D 2X80/ 131, V i c e n d A t o m book s . Half price for good condition. S.a.e. for buying/ selling lists, or books direct to: Allan Guy, 24 Woodsi de Dr i ve, CottingleY, Bingley BD16 IRE. ZX81 + 1 8 K R A M Si ne. Bui l t. Adaptor, Manual , DKAI K R O M -t- literature. Softwar e i ncl udi ng C h e m Star tr ek and many more. + Prog . Book. C120 o.n .o. the lot. v.g,c. Tel : Wok i ngha m 7132947 after 6pm. ZX81 M E M O T E C H 48K Modul e c/ w PSU. Cost (140 used once only. Will accept E90 o.n.o. Phone Newdigate STD (030677) 274 after 6pm, ZX81 MI CRO - CO MP UTE R wi th 16K RAM and E20 worth of software on magnetic tape with manual very good condition, hardly used. E85 o. n. o. Tel : Barnsley (02261 42143 between 2.30pm to 8pm for further information. FOR SALE — ZX80 8K ROM 16K RAM manuals. Marty pre-recorded programs inc. Sinclair business/ ZX81 1K Sinclair built with large household, Chess, Labyrinth a l l keyboard in case plus I/O port and perfect working order. Accept £120 various pr ogr a m s . E 8 0 . B o b o.n.o. Te l : Nor thampton 10604) Wilcock, 41 Berwick Road, Wood (331078. Green, London N22 (01) 889 3571. ZX81 KI TS. Cur e Top Line Slant QUALI TY 2)(81 SOFTWARE, 20 and Ra m P a c k Wobbl e £2. 95. Superb I K Games (Inc. Machi ne Inverse Video Modul e 12,95. Built £3.55. Re pe a t Ke y 13, 75. Bui l t Code), ( 2 . 7 5 . 1 6 K Uti l i ti es i n Machine Code, 0 . 2 5 , I K Utilities, E4.95, All Kits ex-stock. Please add C2.25. 16K Machine Code Editor for 40p P P. D. Looker, DJ I Software, 9 Tweed Close, Swindon, Wilts. the Ser i ous M. C. user , £3. 50. B.FIAO, 1 2 Par kstone Cl ose, Bedford, Beds Te l - 1 0 2 3 4 1 42X81 6 2CO4MP8UTE R, 1 6 K R A M + OS pr ow, Gr aphi c Gener ator , and mother Board + E50 worth of s of t ware, i n c , m i c inv aders , Wor th ov e r E220. wi l l sel l f or £160. Co n t a c t B a n b u r y 5 4 8 9 6 (After 5pm). ZX81 16K almost new, DK 512 Programmed graphic s + 5 1 2 us er definable, KayDE keyboard. Books basic + ma c h i n e c ode. Ta p e s Games - I nv aders • Ches s et c . Mac hine c o d e As s embler/ Dis emblers. Total value E250 + selling E1713. Dave Noonan 01-272 5674 At l ast 2X81 PHEONI X i n 16K. Expertly programmed a nd recorded. O n l y £3. 00. cheques/ PO payable to A. R. Hill, 29 Trimdon Ave., Ackl am, Mi ddl esbr ough, Cleveland, I 5 5 8L.U. ZX81 1 6 K A R C A D E G A M E S . M/ C Mi s s i l e C o m m a n d a n d Galaxians £4.95, M / C Asteroids + Invaders E4. 95. M C Fal kl ands Islands, action packed adventure at E4.95, a l l o n cassette. Ma g n u m computing, 3 Wensl ey Cl ose, Harpenden, Herts. ZX81 wi th 16K RAM. Al so many programs E55. ZX80/ 81 40-key Keyboar d e15. Both items in good order. Phone Atherton 879413 after 5OrnFIVE ZX-81 gr aphi cs games — Y AHTZE E , P O N T O O N , MOONLANDER, NI NE TY NI NE , BLASTOUT. Tape E4.00, Listings £1.00 each. Many others available including SOCCERFI LE. s. a. e. details Adr i an Boone, 1 Chur ch View, To b e r mo r e , Magheraf elt , Co. Derry. "2)(81 MK USEABLE RAM. PIA, EPROM. professional keyboar d and case lino' 6 spare keys and space bar ), Programs # Book s value E30+ , Cost over E260. Sell for 1200 o.n.o. Tel: (0642) 782719" SI NCLAI R ZX81 wi th Keyboard Bleeper, Sinclair 16K R A M pack manual a n d t w o book s , a n d assor ted m i c r o c o m p u t i n g magazines £ 1 0 0 o. n. o. R i n g Stevenage 721659, (Herts.I 2)(81 S T O R E / S O R T P R O G RAMME 1161(1. Store, sort and order 100's of items of information and amend as required. Tape and instructions E4.95. J. Blackford, 63 Eltisley Avenue, Cambridge 3. SI NCLAI R USER J ul y 1982 SUPER SOFTWARE AVAILABLE FR OM CONTROL TECHNOLOGY 18K PACK 123 Pack 3 b 3 include all of AIR TRAFFIC CONTROL -must A nbring i m pianos a t e dinto land. I NVADERS SELF PLAY; PHONE BOOK - ke e p friends r a d a r pick for you and those around you fore laugh. ADVENTURE ATLANTIC smaycbe come r e veery rich n o r marooned fore ve r. BR EAKOU T . SQ U ASH : -a y no u oLANGUAGE t TRANSLATOR translates any European language to any other. d bCOMPUTAPUNT u s p re d ict horse ra ce s a nd footba ll pools wit h yo u 2 X . INDISCO. vide o roadracer. D R AU GH TS compote chequers, w it h kings f e l yBATTLESHIPS. nautical newel battle a t home M ASTER M I N D : brain teaser, o n . asee rt you i r beat p a microelectros mind can . . e oTHIS M r ASSI t VE PAC K OF SOFTWARE I S ONLY M OO s s h o n w n u Y m o b u e r s oA brand new releese. Mrs package of adventures verthen in Basic and Machine nCode are the best value and quality available Ju st compare them with others! c1. GOLF • ogle or two players have a matchplay oft with haridicaps and Progress aaround an 18 hole course which 6 superbly detailed with bunkers lakes. trees, sbushes and greens W e think you we l agree this game has the best graphics @wettable for the 2X81. s e2. DAM SEL IN DISTRESS: you are the knight in shining armour. your quest is tto ride to a va st castle e nd rescue your princess a nd release he r from the tclutches of an evil witch. You must rlotron up a spell to destroy the old witch arid colle ct enough gold to bribe the guards A 're v Be witching Adventure eprogram C O3. STOR M THE TOWER: a s the General of a medieval army you must dooloY your arms and men so you can attack an enormous castle with a huge tower. M You must build armament% and prepare for the corre ct hour to attack but Pbeware of rearguard action end consider intelligence reports with cruel U T E R D A T I NNow installed in many businesses, Cr.11115 with PURCHASE. SALES LEDGER Gfor 100 • entries per week, does daybook analysis, VAT roc a n d end., totals. . password protection plus many more excellent features You * So gel a STOCK CONTROL. MAIL LIST and PHONEBOOK Ea sy to use. designed for everyday wsmall businesses Includes instruction book and tape (17.110 in cl. VAT . hArid does the lob of systems costing hundreds of pounds o w i l l i t ZX ADVENTURE NEW RELEASE Trident (Acorn Atom) I Air Traffic Control (ZX81) 1 . 1 1 ZX AUTOCODER Writing machine code? 1 • • • • 1 1 E . 1 1 Warlords (Vic 20) 1 Moroids (Vic) Astro Battle Zone (Acorn Atom) • 1 0 0 ADVENTURES C8.00 ZX BUSINESS SYSTEM Death Race 2000 (Vic 201 ore Breakout (Vic 20) Draughts (ZX131) ••r I r • Maze of Death (ZX81) Some love it, some hate it but AUTOCODER post gets on with it He lping you produce mechine code programs PrOM BASI C Ea sy to use and ve ry helpful. Converts PRINT, PRINTAT, I F THEN, GOT °, GOSUB, LET INKEYS. POKE, PEEK. C LS. etc ALL M OO I ncl. OUR L o e ss n o t t E i , n . T H I S virt u e F R O M t-M a -itt• E Breakout (ZX81) ZX ARCADE PACK Machine Code Arcette Games for 16K RAM 2X81 Thew Ce le * . Machine Code games come together for 15 00 on one tape. We guarantee these are the Best Value Et Best Quality you can gel INCLUDES UFO BOMBER, bombs. missiles. thrust up down two types ot ALIEN. GALA XIA NS, incredible swooping and bombing enemy fighter SPACE I NVADERS t i n doubt the be st ve rsion evettable se ve ra l Alie ns, crumbling de te nte s . wa v e after wave oil ericrternent PLUS M AN Y MORE ALL ON ONE TAPE FOR l5 00 • If this pack is not the best you've eve •- ALSO h e dAT GOOD w e COMPUTER w i l SHOPS.' l r e f u n d y o u r 1 5 . 0 0 Al prices incl. VAT A and O ro Ple a se send to CONTROL TECHNOLOGY. 3 9 Glouce ste r Road. Ge e Cross, Hyde C he shire SK1 4 5../G 1061 368 75681 1 0 E . _ El E . F , I enclose a Cheque/PO_ for the total P l ADDRESS I ei P O S T C O D E N a A s M e E s e n L-...._ 1 KA YDE Electronic Systems ZX80/1 Z X K E Y B O A R D WITH R E P E AT K E Y l r Ay Fully cased keyboard E 3 7 . 9 5 'oNi Uncased keyboard E 2 7 . 9 5 Keyboard Case E 1 0 . 9 5 This , 4 h l y pr of. . . unal keyboard using executive buttons r o u n d on l op quality computers. It has a repeat key and comes complete in its own luxury case. This is a genuine orofessoonal keyboard and should not be confused with toy keyboards currently available on 'Ns market KAYDE 1 6 K R A M PA C K S he 16K RAMPACK simply plugs straight into the user port at the rear of your computer. It is fully corn...a tible with all accessories and needs no extra power and therefore it will run quite happily on your Sinclair , •ower supply. It does not over-heat and will not lose memory wall. As you may know some makes go down 11K after being On for a while, his 15K RAMPACK is very stable and will not wobble or m u built with s e and y otested u t oa complete l o money s e back Guarantee y o u r r i r n o r a m m e • I Stops mt ovem ent of RAM P ACK and other accessories c o m e s (Not needed with a KAY DE RAM P ACK) f u l l , KAYDE F L E X I B L E RIBBON CONNECTOR KAYDE 4 K G R A P H I C S B O A R D The KAYDE Graphics Board is probably our best accessory yet. It fits nearly inside your ZX81. It comes omplete with a pre-programmed 2K Graphics ROM. This will give nearly 450 extra graphics and with there nverse makes a total Of over nine hundred. The KAYDE Graphics Board has facilities for either 2K or RAM Ifor user definable graphics) 4K of ROM or •ur 4X Tool Kit Chips that will be available shortly. All the graphics are completely software controlled •-rerefore they can be written into your programmes. Here are a few examples: A full set of space invaders — Puckman — Bul ks, Bombs — Tanks — Laser Bases and Al i en Ships. NO EXTRA POWER NEEDED KAYDE 1 6 K GRAPHICS BOARD SOFTWARE •••• only true ZX version of the popular arcade game entipeoL. ' I n all I think this is the best presented moving grapr. p r o g r a m I s e e n " Phi, interface. Space Invaders: The best version available anywhere. , f l entepede I •1 t s the best presented moving graphics program I've yet seen" Phil Garrott nterface. v 3D; 3D Labyrinth. A Cubit Maze that has corridors which may go left, right, up, down. 1 Peckrnen t he latest addition in 81 gamesl. WHY WAI T TO PA Y, MORE FAST I MMEDI ATE DELIVERY Access 1 Post to: 7 , Dept SU F Kayde Electronic i Systems L td The Con ye r I enclose Great Yarmouthd KAYDE 1 6K 8 1 S O F T W A Norfolk NR30 RTel: 0493 E 57867 (Dept S W VISA D o n 't Forget you can always order on the telephone with your credit card All products include V A T are fully built and tested and come with a COMPLETE MONEY BACK GUARANTEE ' 1 1 1 1 Name Address Please add Et 50 PI P for all hardware and 5 , for all software Please make cheques payable to Kayde Electronic Systems Ltd