AN ARGUS SPECIALIST PUBLICATION

INTERNATIONAL AUGUST1983 85p (MATE YOUR LIFE Z80 -based control computer for home, industrial and laboratory ontrol modular construction Oo for maximum flexibility

Z-80 _TELETEXT MAIN BOARD

N I INTERRUP BOARD

.AUDIO....00 PUTING.. AD10....ROBOTICS.. Star sounds BIG NEWS Star quality** ABOUT OUR LATEST Free ADVANCES IN SECURICOR DELIVERY ROBOTICS on all orders over Star features** SEE INSIDE £100 (UK mainland TRANSCENDENT 2000 - Although only BACK COVER only) Add just £2.50 171700 a 3 octave keyboard the '2000' features on lower price the same design ingenuity, careful orders engineeringandquality com- II ponents of its larger brethren. The kitiswell within the scope of the first time DJ90 Stereo Mixer - this is a really builder - buy it,build it versatile new mixer that enables the - playit!You will know constructor DJ to produce a profes- sional performance every time. There you havemade theright are two stereo inputs for magnetic cart- choice. ridges. a stereo auxiliary input and mike input. Other 'plus' features are auto - Complete kit £165.00 + VAT panning for fast or slow slider controls, multi -mixing, ducking, interrupt,input NNW modulation, in short everything . the whole works- AND - under £100 complete! Complete kit £97.50 + VAT

SALES Digital Delay Line - With its ability to give COUNTER Collect your order delay times from 1.6 mSecs to up to 1.6 from the factory. secs. Many powerful effects including Open 9-12/1-4.30 phasing, flangine, A..., chorus, echo & Mon-Thurs. Easy parking, no waiting POWIRMAN CMCNTAL DELAY LANE -

This versatile modular mixer, featured as a constructional article in Practical Electronics can be built up to a maximum of 24 inputs. 4 outputs and an auxiliary channel. Each input vibrato are obtained. The basic kit is ex- channel has Mic and Line inputs, variable gain. bass and treble controls and a para- metric middle frequency equalizer. There are send and return jacks, auxiliary. pan and tended in 400 mS steps up to 1.6 secs. fader controls and output and group switching. The output channels have PPM displays Simply by adding more parts to the PCB. and record and studio outputs. The auxiliary channel also has a PPM display and there is Compare with units costing over £1,000! a headphone monitor jack and a built-in talk -back microphone. The mixer modules plug into base units each of which takes up to 6 channels. To eliminate hum, the power supply Complete kit (400 mS delay) is in a separate cabinet. £130 + VAT Parts for extra 400 mS delay KIT PRICES Free Soldering £9.50 + VAT £27.50 Input channel £19.90 Base unit and wooden front Practise Kit on Output channel £18.50 Pair of mahogany end cheeks£12.50 £19.50 request with your MPA 200 - is a low price, Auxiliary channel £22.50 Power Supply and cabinet high power 100W amplifier. Blank Panel £3.00 fltst kit - useful itssmartstyling.profes- tips, well sional appearance and per- All prices are VAT exclusive formance. make it one of our illustrated. most popular designs. With adaptable inputs the mine. TRANSCENDENT POLYSYNTH - A four octave poly- accepts a variety of source - phonic synthesiser with outstanding design characteristics yet straightforwardcon- struction makes itideal for and versatility and performance to match. the first time builder. Complete sit £49.90 + VAT Complete kit £275.00 plus VAT (single voice) Chromatheque 5000 - a 5 channel lighting system powerful enough for professional discos Extra voice (up to three more) £42.00 plus VAT yet controllable for home -effects. Sound to light. strobeto music level, random or sequential effects - each channel can handle up to 500W yet minimal wiring is needed with our unique single board design. Complete kit £49.50VAT ETI VOCODER - 14 channels. each with independent level con- trol, for maximum versatility and intelligibility. Two input amplifiers - for speech /excitation - each with level control and tone control. The Vocoder is a powerful yet flegible Component machine thatisinteresting to build and packs for most thanks to our easy to follow construction manual. is within the capability of most enthu- kits are available siasts Complete kit £175.00 VAT See our great free SP2 200 twice the power with two of the reliable, durable and economic amps from the MPA 200: fed by catalogue, full separate power supplies from a common toroidal trans- former. Superb finish and quality components throughout - details of all up to (even over) the standard of high prices factory -built units' our range Complete kit £64.90VAT

WORLD LEADERS IN ELECTRONIC KIT DESIGN AND SUPPLY PORTWAY INDUSTRIAL ESTATE ANDOVER, HANTS SA10 3NM. ,sA ORDER BY PHONE (0264) 64455 11 Simply request your chosen kit and quote your Access or Barclaycard Number. cir Riffs INTERNABONAI AUGUST 1983 VOL 12 NO 8

I AN ano,spit,ifal:IFYSLICA today EDITORIAL AND ADVERTISEMENT OFFICE electronics 145 Charing Cross Road, London WC2H OEE. Telephone 01-437 1002131415. YOUR Telex 8811896. ANIMATE owAN LIFE to ..... computerZuf0mtoal4E:44,4.44! for home control FEATURES tr and laborAtury 4. ontrOt Modular OstrUCt.00 DIGEST 11 IC UPDATE 39 for nlixtmum tle xibtilly What can we say? Irreverentir- New ICs for old- at least, one relevancies,stupidstories,potty brand new IC and one replacement press releases, nefarious news... for a hoary old favourite.

MOTOCAR 24 When a leading manufacturer takes READ/WRITE 54 a bus to the car, it' time for big We have a controversy over the changes in the auto industry. Hyconomiser and a criticism of our 01 Poor- i -41 audio buying guide. We don't mind ADIO ROBOTICS COMPUTING people being rude to us, honest. . AUDIO Dave Bradshaw: Editor Phil Walker: Project Editor Jerry Fowler: Technical Illustrator I TECH TIPS David Kitchener: Advertisement 58 Manager Only room for a couple this month Joanne James: Assistant after last month's beano- these are Advertisement Manager for a traffic lights simulator anda Ron Harris .Sc: Managing Editor keyboard alphanumeric lock. T.. Connell: Managing Director 11 PUBLISHED BY: Argus Specialist Publications Ltd., 145 Charing Cross Road, London WC2H OEE. PROJECTS DISTRIBUTED BY: Argus Press Sales & Distribution Ltd., 12-18 Paul Street, London EC2A 415 GRAPHIC EQUALISER 18 UNIVERSAL EPROM PROGRAM- (British Isles) Not being a magazine forhalf MER PRINTED BY: 45 QB Limited, Colchester. measures, this a truly professional Now there's no excuse not to use COVERS PRINTED BY: design with not one but three chan- EPROMs to hold your programs- Alabaster Passmore. nels per octave. this unit will program nearly all the TV STORAGE SCOPE 30 devices that you can currently buy. OVERSEAS AUSTRALIA - Roger Harrison Second and concluding part of our EDITIONS CANADA - Halvor Moorshead state-of-the-artdigitaldesign can and their GERMANY - Udo Wittig EDITORS HOLLAND - Anton Kriegsman convert your TV into a 10 MHz RADIO CONTROL SERVO FAIL- storage scope. SAFE Member of the 61 ABCf Audit Bureau A little gadget that sets servos ina of Circulation 'safe' position if the radio link fails. lectronics Today is normally published on the first Fri- day in the month preceding cover date. The contents of this publication including all articles, designs, plans, drawings and programs and all copyright and other in- tellectual property rights therein belong to Argus Z80CONTROL COMPUTER 65 Specialist Publications Limited. All rights conferred by the law of Copyright and other intellectual property A simple microcomputer basedon rights and by virtue of international copyright conven- the well-knownZ80 tions are specifically reserved to Argus Specialist processor that Publications Limited and any reproduction requires the has a multitude of uses in controll- prior written consent of the Company. © 1983 Argus Specialist Publications Ltd All reasonable care is ing all sorts of things. taken in the preparation of the magazine contents, but the publishers cannot be held legally responsible for errors. Where mistakes do occur, a correction will nor- mally be published as soon as possible afterwards. All FOIL PATTERNS 72 prices and data contained in advertisements are ac- cepted by us in good faith as correct at time of going to press Neither the advertisers nor the publishers can be held responsible, however, for any variations affecting price or availability which may occur after the publica- INFORMATION tion has closed for press 0 Subscription Rates. UK £13.15 including postage. Airmail and other rates upon ap- THIS YEAR'S BREADBOARD EX- READER SERVICES 70 plication to ETI Subscriptions Department, HIBITION 35 ETI PCB SERVICE 77 513 London Road, Thornton Heath, Surrey ETI BOOKS SERVICE 53 ADVERTISER'S INDEX 82 C134 6AR.

ETI AUGUST 1983 3 WATFORD ELECTRONICS TRANSISTORS AC126.'7 35BC212/ 10 912664 36 MP5456 30 00101 10 2543706/9 10 2SC2078 170 AC141/2 30 33 34 CARDIFF ROAD WATFORD BC213 10 102561 41 MPS470 30 V/110KM 263713 2502091 HERTS ENGLAND AC176 140 21) BC213L 10 BF257/8 32MPSUO2 513 V6464F 75 263771 171 2SC2314 AC187 BC.214 10 MAIL ORDER. CALLERS WELCOME V ElF259 SMPSUOS 66 1/14613.4F SO 263772 IN25C21136 las AC188 BC214L 10 17336/7 40MPSUO6 56 V5139144 136 263773 210 2002336225 ACY19/2176 14 Tel. Watford 10923) 40588 Telex8956095 8C237'8 BF594 /5 33MPSU52 85 VNSIAF 2802541 30 ACV?? 4' 75 263819 23' BC2560 30 6F639,40 23MPSU55 50 211107/8 11 25C2612225 AD142 120 BC3078 14 263820 31 81841/79 23MPSU56 90 ZTX109 12 26382213N'250234 74 40149 79 BC308 II IS 8E494/5 30MPSU56 ZTX212 212631168 9225045 90 ALL DEVICES FULLY GUARANTEED. SEND CHEQUE, P..s, CASH, BANK DRAFT A0161 42 8C3I8 SO 511141/71 MOa6 170 ZTX300 13 15 2562138 2111 A0162 42 BC127/9 18 2543903/4 WITH ORDERS, ACCESS/MASTER CHARGE ACCEPTED. GOVERNMENT & 1E1110/81 30C28 220 ZTX302 11 25.1113 275 AF115/6 83 BC337/8 15 263905/6 15 EDUCATIONAL ESTABLISHMENTS OFFICIAL ORDERS WELCOME. P&P ADD SOp PRP 0C35 50 ZT)003 25265 NO AF118 10 110441/61 94 250906 17 TO ALL CASH ORDERS. OVERSEAS ORDERS POSTAGE AT COST. BFX29 N0C36/41 71 217004 17 36128 112 49124/26 8C477 40 2144284 24 10 40 2111328 30 36140 112 AF139 40 264286 15 40 3C516/7 B84eFFXX61 0031/82°C71 172 110 40315 110 27/451 72 2144314 71 AF178 75 50547 /8 12 51/053 30011319.1 40 40316 11 V AT Export orders no VAT. Applicable to U.. Customer. only. Unless meted otherwise. ZTX1500 14 2144400 II AFIN 70 BC549C 14 Bri50 /51 23 170/71 60 40324 108 05 priced aro exclusive of VAT. Plea. ftd 16% tot he total cost including P&P. ITX50112 11 2144427 SO AF239 U10556/7 111 tIFY62 0(42 40326/7 70 We stock thous...ft more Items. It pays to via., us. We ere situat.d behind Watford Footbeit Ground. BC107 10 BC658/9 a ZTX503 18 2144871 15 *won Underground/BR Station Watford 14fth Sr.**1. II8/753 T20070 40 27X504 40347 1/0 BC1078 12 1111 266135/620 BCY39.140 1196155/6 32 C75/76 40 ZTX531 40348 130 Open Monday to Saturday 1.00arn to 8.00pm. Ample Free Csr Perking .pace aftlieble. 10 2115138 IS BC108 fICY45 10 40300 110 PPM STIP29A 32 ZTX660 X255172 13C1065 12 8CY513/5930 II40341,2 70 ELECTROLYTIC CAPACITORS IVPues uII 5131%, 10uF 52p, 47 7110, 63V 0.47 51311 120TIP29C 3/1 2/1687 22 266179 1 0. 1 5, 2 2.3,3.4 7 Op; 10 IS 41 10 10., 15 22 12p. 33 16p; 47 12p: 68 20p, I DO 131., 220 211p, 1000 701,2200 115p.105, 8CY70/71 8FY90 pTIP30A 35 214698 4 40407/8 75 682048 10017p:220 101098 12BCY72 20 21461110 48 40411 24p, NV. 0 6 1646 22 9p: 33 12p; 33C. 470 Pp, 1000 4111p, 2200 10p: MV 1 214691 411 NO 5, 4 7, 10, 22, 47 Sp; 100 11p: 5C1011C 72 !ICY* 24 266190/1 75 40412 138:309 21340 TT11838P314C 2517064 11 10 150 12p. 220 160. 330 22p. 470 26p, 680 1000 34p. 1500 42., 2200 50p, 2200 500, BC114/5 " 265194 03 3300 71Ip: 4700 Pp: 80114 190 euesx28r7s 34yip3 267011 IS 404674 130 *V 47. 68, 100 69: 125 129; 330 lip; 470 20p, 680 34p: 1000 27p. 1500 31p, 2200 BCI17/8 265306/1330 3I369: 4700 71, 50121 96 T1P31C 20010 31 40448 n BC137/9 40 115 2148457/830 50124 BU206 110TIP32A 261131/2 21 40694 MI5 BC142/3 30 80131;32 49 266459 38 40603 1A0-1613 CAPACITORS MV 2200 1311p, 3300 111111p. 4/ 2400: 960: 2200 110p. 3300 1649; 5U206 201TIP32C 422141302 4265485 110 40V 4700 BC1478 I 80133 70 3540673 71 VW NV: 220010p. 3300 Mp. 4000, 4700 511.: 10.000 3200. 15.000 34111; 111V 22,000 31100 1111)2011 200TIP334 26167111152515777 11C14811 0 1313135 BUY69C 440871/2 SO 7STIPPC 78 262160 XS2516179 190 BC149C 80136/37 40E421 POLYESTER CAPACITORS: Axial Load Type 2E0T1P344 74 21422194 311 BC153/4 50138/3940 1408301 3110 TIP34C 400V: I nE, tn5, 2n2, 303, 4n7, 6nB 11p; 10n, 15n, 18n. 22n lip; V 21422204 29254671 215 33n, 47n. 06. BC157/8 10 813140 40 61.12955 70TIP154 110 21422214 169: 150n 200; 220n Xlp, 330n 42p; 470n 62p. 680n t uF Pp;2u2 129 Type %nurture 254715 10 INV: lOnF. 12n, 39n, 11p; 193n. 220n 17p. 330n. 470n 30p-. 680n BCI59 11 80144/45 11114)6170 108TIP35C 1321122224 35 poly Cdpacaors 25C4 709 42p, 1o5 46p: 2,52 Op: 4u7 Pp. Pp. I u' 489 8C160 1113158 MJE180 880 TIP364 130 2623131 2500 2SCA9695 7 RF *DIV1 n1 17p; 10,1 304, 15n 40p, 22n 31p. 33n 4246 47n 100n 42._ 8C1674 10 80205/6 110 1420340 S4 T1P36C 140 2623694 11 BC158C ZSC1061 VACHOICES 1.1,InS.2n2. 10 60246 41426370 100 noom n262483/4V2SC1096 303, 8C169C 10 513378 30 MJE371 100T1P411 02 POLYESTER RADIAL LEAD CAPACITORS 250V 4.17.6n8. 262646 4 38tAil5.5512. FEED-TlittLIUGH 10n, I5n 7p BC170 15 80517 76 MJE520 n11P424 2152104/5 2501173135 10.1. 15n, 22n. 270 Go. 33n, can, 68n. 100n 7p. 150n 220nCAPACITORS BC171 /2 11 80645 SO NJE-521 01 111428 * PCB 18n,22n. 27n, 2512904/7M 22SCS33412 tuft 1120; 130n. 470n 13p. 680n 110. lu 23p. 1u5 40p, 2452 1000pF /450V8p 33n. 39n. 470 BC173 11 8D6954 125 541E2955 MT1P120 70 "ET. Sp 21429014 312501307 0C177:0 15 80696A 125 MJE3055 IN4157. 10u, 22y, 39n. 56n 12p 70 TIP121 /2 73 21429250 10 2SC1449 BCI79 30 36 II33u, 47u, TANTALUM BEAD CAPACITORS POTENTIOMETERS: Rotary, Carbon. 82n, 100n lip 81115 6807102 411 711141/2 IN2143063 8C181 20 BF154/8 25 1411103 30T1P147 n22sScC1166779418.1 : 220u4.. NV. 0 108, 0-22. 033 16p; 047, 048,Track 0.25W Log & Lin values. 100V 126263054 1111 3C182/3 10 330..,100 1-0,1 5 lip; 2.2.33 16p; 4 7. 6.1 VW5000, 161/ E/ .00 IL.rr orftl 100n 120n 10p 8F184/5 XMPF104 301102055 05 2113065 41 BC184 10 12 25C1923 1nir 10 211p, 111//: 2.2. 3.3 11p; 4.7. 65. 10Single Gang 305 150n 180n 12p 6E194/5 MPF105 30T43:6 re 2143252 41 8C1821 10 25019162O 1m2,"2, 11141,15. 31p; 22 30p; 33. 47 400, 100500-2140 &rift Gang Log b Lin Xlp 220.. 270n 160 8F19111/9 111 MPF10.3 40 2143441/2no2601963 BC1831 10 131200 II) 2/16 10V: 15. 22. SW 33. 47 36p, 1005602540 Single Gang D/P Switch 719 330n. 390n 20p 280614/5 ND 10.144 BC1841 10 2SC1957 M 35p Sp: 110 10042p. 5K0 2M013ouble Gang 470n, 560n Zap 512244 a6805008 25"11:15 1106 aft BC188 6 725 2143702/3 102SC1969140122m, 33m, 6800 3(19 BF2248 VMPS412 32 TIS90/91 30 MYLAR FILM CAPACITOR* 2143704/5 102502028 43rn 800 luF 34p 2u2 500 BC212 10 81245 30 MPS1155 30 UC734 INV 1nF2, 4, 4nF 10 Sp, 15nF. 22n SLIDER POTENTIOMETERS 263706/7 10 2SC2029 21610301 76p 30n. 40n, 47n 7p. 56n. 100n. 200n Op0 25W log and linear v645..60,1.6 INV: 4701.1 12p. 560 50060 single gang CERAMIC CAPACITORS 501/' Range 0 5pF to 10nr dap. 15nF2200 ACCESS ilecLir20141 552; MC149514961 NaTDA1022 499 7440 74180 40 5301 360 LS162 33n1, 47nF Sp 100nF /30V 7p Orders TDA1024 36 PRESET POTENTIOMETERS 115 7441 74181 1% 5412 380 200nF /6V So. ICL7660 248 58C1596 NO7001034 L5163 36 0 1W 100 5M Miniature Just phone your 360 7442 74182 80 5470 325 orders through ICL8038CC330 1.401648 no LS164 43 Vertical or Horizontal 7p 1041490 360 7443 74184 90 5471 PO LS165 50 POLYSTYRENE CAPACITORS We do the rest IC1.82114 150 MC1709G n70/12002 7444 0.25W 100 a 3-3M horiz. largerll2p 1CM720541150 226 74185 n 0472 1150 LS166 52 10pF l0 1 of Sp, I 5nF to 12,1 10p 1,1 092350234 1.403302 V2042004 7445 0 25W 200 4-7M vert. 12p ICM7207 475 mctafte in NO 74188 200 5475 -100 L5188 84 7002020 320 7446 ICM7215 IMO 68033600 m 74190 40 5671 CD L8149 00 111.0E0 MICA IVekres In pF I 8224 1342030 214 7447 110 15309928 NO ICM72164J EP MC3401 74191 48 LS170 70 2. 33. 4 7, 6 8. 8 2. 10. 12. 1518, RAM COMPUTER 8225 7080701 7448 611 TMS9929 ICM72168 122 420 74192 48 _S173 50 22.27. 33. 39, 47, 50, 56, 68, 75 82. MC3403 75 711170 so 7450 FOR ICs 8226 250 TMS9995 612 ICM7216C0221403405 74193 41 L5174 36 85. 100, 120. 150, 1140pF 16p each INTL430C 90 7451 74LS 8228 720 ULN2003 75 ICM72174 750MC3423 74194 40 L5175 36 200. 220250. 270. 300. 330360. BBC 40 TL509 110 7453 LSOO 1702 330 6247 271) UP07002 426 10.0224 785 MC4016 00 74195 n LS1131 90 390, 470, 800, 800, 820 21p each 8250 7454 L501 MICRO 1802CP 660 IN ZBOCPU 2.5 2311 ICM7240 303 61110 350 7106100 40 74196 44 LS183 105 1000. 1200. 1800. 2200 30p each 82514 71_062CP 7460 L502 21141-300n 90 MO ZOOACPU 4M 047566 alMFC6040 75 74197 40 LS190 36 3300,4700.1 110peach 8253 111_064CN 7470 L503 1;12 *MAP 21141-2000 105 400 300 0687556 55(50398 6137: 74196 19) 115191 36 2147 425 8255 MO C7C NO 11071CP 24 74199 DI LSO4 38 MINIATURE TRIMMERS Capacitor. 2611 7473 LS192 Mks . 62564C (36 TL072CP 46 74221 L505 12 2 6pF, 2 10pF 22p, 2 25pF, 5-650F 300. 2532 300 21304 CTC NO 7474 64 LS193 37 66 8257.5 NO 28013 EL074CN 100 74246 LSO8 12 2564 875 1104032'LL VS LSI94 36 104610 360. 2.11295 '41'11165291254 7475 2250 4 7751:2C 11081CP 24 1009 12 2708 250 6253 2110 DAPT486 226 74247 120 LS195 35 L33NO noaDART 550 TL062CP 7476 74248 LS10 12 2716.5V 250 [17 1100440°4422 160 120 LS196 RESISTORS Carbon Film Hi -Stab 5% :ii; 3231 P4N E5E6 2931 11083CP 76 7480 LS11 12 * 2732 295 385 280 DMA 675 1C7130 6634.,, 100 74249 IX LS197 46 8219 340 7421 1512 13 395 TL084CN 10 74251 2754 8282 450 2800407 1C7120 302 1.0221 56 6263 450 ZEIO PIO '5,1.` 225 TL091CP 7482 74259 LS13 III RANGE Val I .99 100. 127128250 625 260 1107137 160 LS240 56 6204 350 316 7483 LS14 21 025W 202-104 624 3p 1p 3242 590 Z80 PIO 275 mNE555 21:U42240 120 74265 II 15241 56 0205 305 1E347 7484 1515 12 025W 202. 4.47 612 3p 1p 4027 100 280 510 1 1150 120711540 230 74273 160 10242 56 8288 010 48 7485 L020 12 1W 202- tom (12 lip 4p 4116.150n 100 Z804 510 19 326 1)05430201 1s0 74276 120 L5243 56 8P83048N MO 115-3F1:31 n 7486 LS21 12 2% Mast FOrn 624 Op 4p 4116 200n 90 146561 0152001 go 74278 100 10244 50 137764 1E355 a 3111 7489 1522 12 1% Mets1 Film 624 ft Ip 4118 250 325 665628 410 ULN2003 75 74279 60 15245 70 8727 100 117754LF357 R 7490 4164.200n 425 74263 TO 1S247 50 100 +price applies to Resistor of each 1,0NE564 420 ULN2004 75 7491 4334.3CMOS 211284 120 74294 151 LS27 13 Noe not nutted 8731 mNE5657. INU162283 100 LS248 56 '1143 325 360 LINEAR ICs 74285 1% 1528 14 1161131 m116566 115 UPC575 275 LS249 56 8135 10 1::1 74290 LS30 13 RESISTORS NETWORK S.I.. 4532 3 360 140 UPC1025H 375 7494 105 LS251 30 07976 10 555CMOS IN 154301* 74293 1532 13 7 Columned 18 pins/ 1000 POO. 16 242 467 4532 4 360 024NNE5E24702V UPC' 182 320 10 LS253 P 9364AP 702 76 1/4307 410 1495 101L 476 1006 560 146671 775 74297 MI IS33 16 LS254 80 2660 4816 100ns 225 709C 8 om 1M30217 400 UPC1156H 7491 9602 120 UPC1366 1% 74298 100 1537 15 Common.* 19 pins11500. 1800. 2700 33012 16 5101 450 220 710 44 ,NE5532 145 7497 LS257 30 414261531C125 1038 15 262.4.7.5138. /OK 226.4764 ram no hjlEm55.04 1s050 X112206 XC 74351 116 6116-150,5 34049261532A 125 741 6 Pc 74100 L5258 35 1161.120500 XR2207 375 74365 30 1040 13 LS259 56 AM261.5334 126 747C 14 fun40 111183843M311198N 74104 LS42 6117.100n 460 1,,.. FtC413617 SO XR2211 575 74366 n X LS260 22 BRIDGE AY.3.1015300 748C 8 pm 21 1131413.404 6C4558 74105 LS47 6502CPU '' 46 XR2216 675 74367 30 LS261 100 326 AY -5-2376 7538pr. 94 74107 1548 DIODES RECTIFIERS 65024 NO 603 105 .....556613 226 XR2266 380 74368 3) 4 L5266 20 810 IN 74101 LS49 50 6504 250 650 00681017 276 1542352 ...SAB3209 426 214414 80 74330 75 LS273 54 COM8116 940007 3513 16038 47 74110 LS51 14 1614/501/ 8505 7133 S683210 325 ZN419E 180 74393 10 15275 125 44119 OW131 154348 st 74111 LS54 14 20 6520PIA 100 VS 4115 244235 130 74420 10 LS279 30 44129 14/1000 114349 usSA53271 74112 14 0036916 MO 41.1-1320 225 130 LS55 AAT30 15 14/4000 6522VIA 281 SA54209 U621024E LS280 10 75 SERIES 05613151206255 47.1.5050 111 168358 74116 1583 120 Is14/600V 6530 (11 507402 211 2514250 346 74C LS283 N 84100 058820 AY1-5051 190 176 74118 LS70 100 75107/8 16 6532R6I01 570 mo.51490 NO Z144260 300 1-5290 40 84413 20 24/50V 058830 110 AY -1-6720210 74119 L573 18 24 24/200V 75110 90 2N4276 600 74(244 196 LS293 40 81100 6545811C 805 058831 AY -3-1270 1111.43'4371311087 74120 LS74 15 75114/5 160 126 730 254286 410 74C245 1% LS295 76 8Y126 12 211/400V 6551ACIA 050 058832 250 A13-1350 350 10131111. 74121 LS76 20 12 2.4/800V 75121/2 130 6592PC ZN429E 210 74122 74C373 240 LS298 80 81127 1320 59365 6311 AY 3.8910420 114382 LS76 15 MO 64/100 v 75150 125 .1..4116 SSSN751N7266°1321ND M124°M IN459 740374 246 LS299 150 CR033 6800 220 09366 (318 Bookie% for 74123 LS78 18 406A/4000 75154 126 1.1"S6762276 15 2510340 200 74125 74C922 420 LS320 200 049 641102 750 F01771 615 AV -3-6910 11:338864 IN LS83 31 12 64/6000 /5159 125 55176477 4X)ZN10400 81115 740923 500 LS323 180 0.447 6803 150 F01791 822 AY 343912825 04387 74126 1505 42 12 106/2000 75182/3 ZNA234E 850 L5324 11111 0470 6804 180 F01795 AY 5 1230 450 L44389 26 74128 LS86 16 104/6005 75188/9 516629 299 LS325 233 0A79 6005 PO101799 CM AY -5-13170030 LM393 45 74132 74S LS87 350 20254 200V 75322 140 74136 10326 240 0461 6808 tieF01797 121 41.6-1350 1110 75 LS90 24 15 75324 3113 LS327 0485 254/600V 6109 IGO 0.411."147M7154325:35CN 74141 74500 30 240 H026501 75 CA3011 130 ToT1:405204 175,o 11174 LS91 10 0490 9' 81164 75361/3 160 74142 502 30 LS347 96 1546402 NO CA3012 176 LS92 32 8: V 75365 150 T8 It 74143 503 30 LS348 90 0491 854111 DIL 11451060N IMO CA3014 278 *TA722.2 150 7400 11 LS93 23 0495 75450 R 6821 100 15811171 7401 11 74144 SO4 30 L5352 62 16581546 CA3018 8. 326167120 190 LS95 40 a 75451/2 62 681154 700 11682917 7402 74145 505 68 L5353 62 00200 MC1488 CA3019 110 1111747310 13 11 LS96 96 L5356 8 75454 70 6840 376 74147 SO8 240 00202 58C1499 16 043020 210 ' ' ''T446214)0 736 7403 12 60 L599 99 LS363 140 4 ZENERS 75491/2 6843 (12 74148 6914 MC14411 690 CA3023 210 47446614 190 7404 13 520 40 LS107 40 LS365 28 6 Range 21/7to 6845 NO 74160 S32 LS366 32 *4916 MC14412 CA30264 111 1,543302 75744700 275 7405 16 70 LS109 23 5 39V 400mW 6847 660 725 74151 L5367 28 114001/2 SCR MC3446 CA3035 3111 60TAA900 126 7406 29 574 75 LS112 22 153613 Sp ftch 6850 110 MO 35 64003 8 CA3036 270 LL1M39098:4317N Ian 1756601110 169 7407 20 74153 S86 65 L5367 80 to TIHYRMTORS 6854 MC3447P 315 LS113 20 144004/5 6 Rance 31/3 8118 CA3043 VS 7408 14 74154 5112 00 L5374 55 220 MC3486 175 L5114 22 15375 50 64006/7 7 33V 1 3W 54'40V 32 68821 1143914 7-845400 276 14 74155 5114 BO 54C3487 175 CA3046 315 IN 7409 LS122 15377 85 4 160 each 5A 4000 40 6875 IN 74156 36 144148 CA3046 70 7410 14 5132 110 L5123 36 1537e 40 54 600V 48 68000 MC6845 1125 65401 15 C03048 22014::15:°28455r116 01(4648XXL 7411 16 74157 S133 50 LS124 90 15319 110 19 84 300V 10 74C922 400 MC6846 IN 74159 163114 395 65404 CA3059 MS 30110 13A6X151, MO, 7412 11 5138 100 L0125 24 84 600V 10 80804 MO 5463886.258 V 74180 L5385 250 65406 17 ^A3075 213 7413 18 5139 116 L'I26 25 L5386 54 124100V 78 8085A NO M1452800 SP 74161 66408 II C630806 70 10 7414 24 S157 226 LS132 33 L5390 44 9 TRIA CS 126400V BON 51145303 635 74162 L5393 42 S44 * (18 063081 IN 11 7416 20 0158 210 LS133 30 1268000 IP 8118 10 MM5307 1275 74163 15394 00 5921 P 3A 200V 54 VS CA3066 48 80 7417 78 0188 140 15136 24 16396 550 81106 150 8123 126 54545387A476 74164 64/100V 40 3A 400V 66 CA3089E 215 7420 IS 5189 140 LS138 25 L5300 140 81116 IN 1.45458174 700 L5399 641400V 60 84 100V 10 8155 NO CA309040 375:113qt' 112;111811- NO 7421 20 74165 5194 196 LS139 N 150 C106D N 8156 19M74C922 420 1403756 L5445 100 6A/9005 ST 84 400V 80 CA31236 IR MD Ty6BA95°Agggo 5603°° 7422 70 74186 5195 196 15145 79 LS447 11C44 24 111) 3 25131 NO 100 84800V 115 811.595 IV V:43130 1.101204 MO 7423 20 74167 5201 AO L5147 15465 15 11045 R0-3.251314150 103 12A 100V 1$ 29 811596 SO CA3140 406801301 15 7425 18 74170 5225 240 LSI48 L5090 200 TIC47 SFF96364 RE TC9109 775 75 1.9540 12A 400V 82 36 1311597 10 7426 15 74172 250 75 SP0256AL2 Ell CA3160 4MC7303 MI ao S241 L0151 40 115541 SO VARICAPSI 136 21%062 32 811598 700220 7427 74173 124 800V CA3181 TNPAC13041 210 15 5244 290 L5153 40 L5524 SO 285064 31 8202 C25 TMS2716 3V 7M TCA2700 NO 74174 164 100V 103 CA31621 4110 MCI310P 150 21 5251 170 LS155 30 L56401 100 2144444 130 8205 TMS4416 2 475 TCA2804 230 180 ,56102 64 16A 400v 105 225 CA3119 300 MC14 5 7430 14 74175 5257 170 LS156 16 8212 TMS4500 614 700940 15645 180 8810513 16A 800V 110 , 74176 no 15804532 3 350HAI 330W 240MC145106 OM "S 7432 22 5262 PO LS157 25 15658 /25 56106 250 5000 220 8214 43 1141388 29MC1446 507C4965 146 7433 22 74177 S287 MS LS158 30 /9669 120 981098 8216 TMS5100600 *254 800V DIAC IN iCL710611 NO MCI469 MDTDA1004 210 7437 25 74171 S288 210 LS160 32 ,S,0 100 MVAM2 181 128000 120 ST2 25 ICL7107 975 MC1494 spa T061008 310 7438 22 74179 S289 200 15161 37 LS73 550 LS74 5,0 AMP ETI AUGUST 1983

SWITCHES OIL SWITCHES VEROSOARD 0,,n VO Board tap IDC CONNECTORS PANEL RELAYS 2A. 250V (SPST) 4 way 65p:6 way 100p; DIP Board cladplain PG Poor Few*rental. METERS Miniature. anckieed, PCB mount. SPST 33pOGGLE 8 way 85p; 10 way 100p Vero Strip 210 31,4 115p Win IoM wmrCaul DPOT 44e (SPOT) 4 way 1110p nip we Feet SINGLE POLE 21/2 5 100p - Poe 00 .46 x 36artre RI.91 2060 Creeilnr1r17C. 1063 to' ROTARY SWITCHES 334 - 334 Connect SUB -84131130131.5 103P -PROTO DEC. 10 way Sp120p 0-5041 19.5V). 10A st 30V DC or 2513FAC (Adjustable Stop typal 334 5 1169 0-100aA SPST on/oll 64p Viral:kick Nip 16wee 110p SPOT driver 410p 1 pole/2 to 12 way, 2p12 to 6 way, 314. ITyap. S -Dec Sap 20 way 131111 lap DOUBLE POLE Clsingeovw. GA 30V SPOT centre off ap 3 pole/2 to Away; 4p/2 to 3 way 46p 43'4.17 4119 7700 Eurobreadbeerd 6259 DC or 250V AC Pitt of 100 inns 26 way Gap210p gre SPOT biased both ROTARY: Mains DP 250V 4 Amp ois tlimboani 1 Tip 34 way INN3209 0-5mA 016-100 530 CoN, SY DC1564 Willa Spot face caner 15139 was 106p on/off Np Superstrip SS2 13600 150p3409 -10mA 11 1p Pin insertion tool1809 40 way CPIOTtags 710 50 way 7100 0-50mA 616-111 2050 Cod 12V DC (10V7 MDT contre oft No ROTARY: IMak-ormitCh) 60 way 720POhs 0-100mA 19651 Tap ()POT biased both Maks a multiway switch. Shafting as- VERO WIRING OALO ETCH 0-600mA 111.03-114 7400 Coil, 24V DC 1226 to RESIST PEN ways law sembly hasadjustablestop.Accom- PEN I- sp000l 340p -IA 37V) DPDT 3 positions modates up toe wafers Spar. .pod 190 Phis spare fit/ 100p EURO CONNECTORS 0-2A on/on/on 1116p 0-25V AMPHERIOL PLUGS (mac 6 pole /12 way DP switch). Comb. Op Firm* Socket Mule 3 -pole 2 way 206p 0-50V AC IEEE 24 Way 806 Mechanism only 110p Sm. AngleSm. ULTRASONIC 40 0-300V AC Centronics PareNei 36 Way solder630 WAFERS, !make before break) to fit FERRIC CHLORIDE Pins Pins Pins Pins SUDS 260V: 711161111101.10ER Centronics Parallel 36 Way IOC the above switch mechanism 1 DIN41817 OPOT IA 141, lb Wig Anhydrous 40KHz 335 pr -vv. 415p each Centronics 36 Wsy IDC Female 6209 OPOT IA c/off 15p 1 pole/12 way; 2 pole/6 way; 3 00111/4 trap + 500 ESE 31 way 170p - - 175p DPOT V2A 130 way; 4 pole/3 way; 6-/2 wey Np 03441612 CRYSTALS Maine DP 4A Switch to fit 2 32 A a B My 310p 3200 2169 BUZZERS,miniature,solo -state COPPER CLAD BOARDS 32.71111KH: 100 6V. 9V & 17V Spican 4p. Sown Op D15141812 100KHz Ia 7118 fibre Single- Double SRBP 310p 310p PIEZO TRANSDUCERS PUSHBUTTON IA 2k324aC 36p 3I 200KHz 2111 ROCKER' 5A/250V SPST glats6 bled 1p1.2%1 with 11)inm Button 289 11.1p DIN418123:(32 465KH PB2720. 1419 ROCKER. 10A/250V SPOT 311p A .t.B.0 31109 280p 3Up SPOT latching + 12 alp 1MHz VS DPDT latching 1444 ROCKER 10A/250V DPDT c/off 116p 175p 2251, ROCKER 10A/250V DPST with neon 1.008M Za LOUDSPEAKERS SPOT moment00p EDOE 1 Nut: 1S2 Mwature. 0.3W 80 DPOT moment 1414 1119 DIL SOCKETS OIL PLUG (Header) 1.61AHz THUMSWHEEL Mini front mountinsav CONNECTORS 1U11110111 CAKE 3lin, 2lin, 3in Low WM* .1 .150 Star IDC 1.04Hz 305 Mml Non Locking price par foot 2;n400, 640 or 600 DimedeSwleM Module Prof Weal 2 .15 way - 1409 14pin 440 1343264 WO. Push to Make 10p B.C.D. SMIch Module . Vfp 2, GreyColor Push to Saint 9PM299IP 2 x16 %ay 11113 2.01610 210 25p 710 10 ray 114 21110 Mounting Cheeks IP. Pall Ille1/* 24p in p1 1711p 24117S61 2110 ABM UHF MODULATORS 2x22 way Who yap 16 um Up 43. 16IIspin Ns 2x23 way 175p - 400in alp 2540 3.27161 164 StarKW1161AH: 3211p 2011WY 19 Np 160n Up Np 2 026 say Ulan* 3.5794M N Wideband8MHz 411119 JUMPER LEADS (Ribbon Cable Assembly) 24 way 40p MP ETI 20Pin 3011 Bap 28 way 110p - 3.08044 3/0 Length 14 pin16 pin 24 pin 40 pin 22pin staNp 2 . 30 ivay 246p - Ns OIL 34 vow 1110p Op 4.0MHz 116 PROJECTS Single ended DIP (Header Plug) Jumper 40 wry ap We stock 24pin tie 70p 2 . 36 way 216p - flOCKIITS 4.032MHz 218 MEMOW New Version 24 inches 145p 116p 240p 3110p SO um 141101310 Meet of 211oin Up OOP 2 . 40 way 3112P - 24* Nso 4.162MHz WATFORD'S Double ended DIP Header Plug) Jurnpei 40pin 30p lap 2 v43 ray 3169 - 29 pin sus 0 war loop 11I0e 4.18130461 314 the pens 6 inches 2136p lap 300p 41159 2 x76 way 560p - 40 pin 11119 4.43301561 SO Minnie Menlior IC 12 inches lap 216: 316p 41109 5.0MHz 164 A 45 Monitor chip special 001161.10 24 inches 210p 236p 346p 640p ANTEX SOLDERING IRON 5.146M1& XS to produce the beat from yaw: 38 inches 230p 2509 376p EL 5169 C -15W 495p CS17W 495p 5.2425161 310 SuPerbard Seas' EtII, Enhimped SMUT V' CONNECTORS 6.0134: 10 IOC Female Header Socket Jumper Leeds5" G 18W 520p XS25W 525p etbilseas Superhard & UK101. As reviewed by 20 pin26 pin Spare tips, assorted saes 85p 0 I' ouch 15 25 37 .1414.114z 150 Dr A. A. Berk in Practical Eiactreoics, 34 pn 40 * way way way eye Single ended 1110p 200p 260p 330p Spare elements 225p 20 ray Male 6.56364114, 23 June 1901. 7.01411/ 110 Double ended 290p 370p 480p 5215p Iron Stand with sponge 175 Np Solder lugs 80p105p I 160p 250p 7.11111MHz a0 Only tie Angle pins 150p210p; 250p . 355p 77325501Z 250 PCB pins 120p130p 195p 1295p SSC MICRO TRANSFORMERS: VOLTAGE REGULATORSSOLDERCON PINS 7 SHAH: 2110 Female 151 3-036; 8-04V; 9-0-9V;12-0-12V,15-0-15V IA 70220 PIN& Casing 105p 0.0300 AND UPGRADE KITS Solder lugs 160p 2009:345p 8.08333M 310 611100mA 111p ye -vs 10441 fp making OIL Angie pins (Our BBC Micro Upgrade Kits will pob mountlng. Minieture, Split Bobbin 5V 7505 ap 7905 45p or DIL Sockets 165p 215p 290p 440p 6.567234 171 100 pins PCB pins 150p 1009 12459 420p 9.00MHz 110 save you Esse . .1 3VA: 24V0.25A; 2s9V-0.15A; 2a12V-0.12A; 12V 7812 40p 7905 SOP 76p Covers 2:06V -0.1A 15V 7815 40p 46p 600 pins 3110p 90p1100p 10.0MHz 175 BBC Micro 200p 7912 !DC 25 way1/' PlugPlug 385p; Socket 450p WA: 2s6V0.5A;2i0V-0.3A;2s12V-0.26A; 18V 7818 Np 7915 46e 10.24MHz XS Model A £299 tint) VA 2a15V-0.2A Zap 24V 7824 40p 7918 4SP ALUM BOXES 714142 160 Model B 099 (Intl VA Standard Split Bobbm type: 7924 elp 3s2v1- 12014H2 176 NA: 241A0.15A; 100mA TO92 Plastic package 402; 26 way '13' CONNECTOR ,RS232) 12.6201.1 300 (Our BBC Micro Upgrade Kits will 2t0V-0.4A; 2.12V -0.3A. Jumpe Lead Cable Assembly 2016V -0.25A ner 14.311144 170 save you Cass . 220p 5V78106 30p 791.05 10p 4 lik 18" long, Single and, Male MA: 2.4.5V -1,3A;2.13V.14; 6V 79106 30p 4 s4v 4115p 16.011141 200 16K Memory 18 x 4816P) CIS 24V-0.64. 18' long. Single and, FerniNe 626p 2.12V41.5A; 2.15V -0.4A; 2020V -0.3A BV 78108 30p 111.0414. iN Printer User I/O Port Kit DMA 78112 5.401 36' long, Double Ended, M/M 11325p 15.4324 NI Isio 1350 Isbol 12V 33p 79-112 1109 36" long, Double Ended, F/F Complete Printer Cable 36" £12 3AVA: 2:4V -1.6A; 241V -1.2A; 2.126-1A, I5V 78115 30p 79115 Blip 0x402' 11:160p 20.0414z 30 36' long, Doubel Ended, M/F Map 191113411AH. Disc Interface Kit 205V -0.11A; 2s2ovb.ea 330p 100p plop) 12.29. (' 110 NVA 24W4A; 24V -2.15A; 2:12V -2A; 2:(16V- 1CL7680 04$v TA/1460 50p 11.26.21' 24,0MHz 119 Analogue I/O Kit 804104 375p TDA1412 1.56; 2)00V -1.2A; 2,35V -1A; 2v30V-0.13.4 1404195 110p (1.4x2 24.9304/42 315 Serial I/O Kit 131.70 150p 710105 t. 5V/5A 11110p lap (60p pain 8.4.3 24.694 164 Expansion Bus Kit £1.10 154309K ISp 78512 a 12V/5A 705.3 27.644161 170 SilocieNY wound forMultirsil Computer PSU. SPECIAL OFFER Complete Upgrade Kit from Model 50VA Outputs 5V 5,4;r 12V,+ 25V,-5V. LM317K 120p 110p 27.1463 1410 14.4317KP A to Mod. 13 £43 -144 at 1A 575p 160P PEW) Np 71150 a 5V to *1125V 100410' 2764- 1+ 50+ 39.6656761 131 194323K 410p5A NOVA: 2.1211-4A,2,115V -3A; ellas complete range of BBC 2s20V-2.5A, LA4337 79/40 a2.25V to 24V 250n 425p 395p 2:35V -2A; 2:306-1.5A; 2460V -1A 1120p 175p 1719 1205x3' 100.0MHz 255. Plugs, Sockets, Leads, Peripherals, il.64723 Va. Sap SA Nip 116.3410 to be added over and above out nor- 12x8v3' Software etc. Send SAE forlist malOE poWel chirps). CMOs OPTO 4075 4541 COMPUTER CORNER 4076 ELECTRONICS NEC PC13023BE-C PRINTER 10 4543 EPSON FX80 PRINTER. 10" 160 cps, Tractor/Friction feed, Bi- 40400001 10 4077 4544 LEDs with Dips £320 £7 car) 4002 12 4078 4548 TIL209 Red 10 directional, logic seeking, 9 x 11 matrix, Hi-res bit image. 4000 N 4081 4549 TI1.211 Gm 14 normal, Italic & Elite car. Super & Sucscript, proportional 4007 14 sou 4553 T1L212 Yak 14 spacing, underlining, 2K buffer £395 (£7 can) MICROLINE-82A PRINTER 4008 22 4066 4564 715.220 .2' Red 12 BO column, 120 CPS bidirectional, Logic 4000 24 4086 4555 .r Green, Yellow or seeking Tractor& FrIctionfood. 9x9 matrix, 4010 81 4009 45511 Amber 14 Mx100 EPSON Printer. 136 Column, 15' carriage, plus sit the true deCenders.40.66,110 or 138 colme per 4011 10 4093 4567 0.2' Bi colour features of MX8OFT/3 Only £425 + corr. IMO 4012 10 4094 4658 Red/Green £325 4013 20 4096 4659 Green/Yellow 711 4096 0.2' Tri colour SEIKOSHA GP100A. 10" Tractor Feed, 80 Coimn. 3OCPS, 4014 40 4660 Normal and Double Width Char, Dot Res Graphics.. rum (5.7 car) ORIC MICROCOMPUTERS 4015 40 4097 4501 Red/Green/Yellow N 4-8K RAM now in stock £147 4016 4098 4642 Hi-Bright:ow Red ID SEIKOSHA GP250X. 10", 50 CPS. Normal and Double width 4017 32 4099 4604 Fleshing red 4160 0.2' red ia and height Char. RS232 and Centronix Intrf standardE240 1E7 carl 4018 46 4668 Printer Cable for our printers and BBC 4019 26 4161 4669 Square LEDs, Red, £12 4020 42 4162 4572 Green, Yellow 30 SOFTY II. An intelligent Eprom Programmer and Emulator. MONITORS 4021 40 4163 4580 Rectangle StaCkeble Accepts a 24 4174 pin5V Eprom. Hu Memory Map TV Display. RS232 MICROVITEC 1431. 14" Colour Monitor. RG8 4022 40 4581 LEDs and Centronics I/P & 0/P. Copies, Emulates and programs. input las used in BBC prop.) 4023 13 4175 4582 Red, Green or TM 18 E250 4024 32 4194 4583 Triangular LEDs RS 232 and centronics routines standard. PSU included. LIN BMC BM1401 14" Colour Monitor, RGB input 4026 13 4408 4584 Red IS TEX EPROM ERASER Erases up to 32 ICs in 15-30 minuted 133 £235 4020 80 4409 4685 Green or yellow 22 4410 TEX EPROM ERASER with a safety switch ZENITH 12" Green Monitor, Hi -Res NO 4027 26 4597 LD271 Infra Red 40 £35 Carraige on all Monitors is E7 (Securicorl 4028 N 4411 4599 5E14206 Detector 1111 TEX EPROM ERASER plus our SolidState- ELECTRONIC 4029 45 4412 40085 T1132 Infra Red 611 TIMER 4415 £44 4030 16 40097 TIL78 Detector SO ELECTRONIC TIMER, Solid state, 15-30 min. Connects directly 4031 12 4419 40098 71138 06 CASSETTE RECORDERS toaboveErasers. 4032 BO 4422 40100 TIL100 so ProtectsyourexpensiveChipsfrom for MICROS 4033 126 :42 40101 BARGRAPH. Red 10 overcooking. Our timer pays for itself in no time £15 Slimline, Portable. Cassette Player, special for 4034 140 40102 Itipments 225 SPARE 'UV' Lamp bulb Micros with counter. AC/DC operation. £28. 4035 45 4450 40103 ISOLATORS 4036 VS 4461 40104 1174 65 POWER SUPPLY. Regulated with Overload protection. Variable 4037 115 4490 40105 11074 NI Output, 5V to 15V at 4A. Professionally finished ,C3B 4038 144 4600 40106 11.074 115 4030 3E0 4601 40107 TIL111 /2/4 so MULTIRAIL POWER SUPPLY KIT.Especially designed for 4040 40 4502 40108 T11117 126 Micros. Tested output: + 5V/5A; + 12V; +25V; -12V of 1A E37 We stock a vast selection of BBC 4041 40 4503 40109 4333 Photo MICROCOMPUTER HARDWARE 4042 40 4504 40110 Darlington la C12 COMPUTER GRADE CASSETTES in library cases 40p 4043 40 4506 40114 Illeuerneet 17eplstre SOFTWARE, FIRMWARE, BOOKS 4044 40 4506 40161 81" & 91" Fan Fold paper 11000 sheets) O + 1509 can 4046 105 4507 40163 TIL312 .3' CA 106 ADD-ONs, etc. Please write-in for 4046 4508 40174 111313 .3- CC 105 4047 40 4510 40175 TIL321 .5' CA 116 details. 4040 4511 40181 TIL322 .5" CC 115 4049 21 4612 40182 01704 3' CC N 4060 4513 40192 DL707 3" CA ID 4051 411 4514 40193 FND357 Red 1111 4052 60 4615 40194 FN0600 116 FLOPPY DISC DRIVES TEAC also Compatible) 4053 60 4516 40195 .3' Green CA 110 FD50A - Uncalled Single, 40 track, 51', S/S, 100K £130 4064 80 4517 40244 .6' Gaon CA 2115 CS50A - Single Cased with PSU, 40 track, 51" S/S 100K ....ENO ULTIMUM 4056 46 4610 40245 .3' ± 1 Red CA 160 4066 as 4519 40257 .3' ± 1 Green CA 150 CD50A - Twin Cased with PSU, 40 Track, 51" S/S 200K ....E350 WATFORD'S or most versatile 4067 11115 4620 40373 064176 22 CS50E - Single Cased with PSU, 80 Track, 51" S/S 200K._1250 MICRO EXPANSION SYSTEM. Ideal 4059 425 4521 40374 LCD 3; Digits 416 CDSOE - Twin Cased with PSU, 80 track, 51" S/S 400K £475 4000 4522 45106 LCD 4 Digits 530 CS5OF - Single Cased with PSU, 80 track, 51" 0/S 400K for interfacing with APPLE, ATOM, 626 C330 4061 1180 4526 LCD 6 Digits CD509 - Twin Cased with PSU, 80 track, 5) D/S BOOK ESN DRAGON, PET, RESEARCH MACH- 4062 644 4527 0 PTO 4003 4528 MITSUBISHI SLIM LINE: Uncalled, Double track. Double Den- INE, SPECTRUM, SUPERBOARD, LS400C 2111 PIN 01001 4001 as 4529 3134478-002 atop sity One Megabytes. WA". Track Density 96TPI, Track to track 4067 as 4530 OCP71 120 access time 3mSec VIDEO GENIE, IX81, etc. Low Cost, ORP12 £225 40111 14 4531 REFLECTIVE Optical Drive Cables for BBC. Single e8; Double £12 High Spec. As published in Practical 4000 4532 ORP61 16 Switch type T11139 170p 10 Verbatim Diskettes Electronics 4070 13 4534 2146777 16 SLOTTED Optical srS.S.S. U. 15 yrs warranty) no startingfrom November 4071 13 4535 B P us NI Switchsimilarto RS 10 Verbatim Diskettes 5 D.S.D.O. (5 yrs warranty) OD B PI/421 1982. 13 4538 215 Conek's 11/11p 10 Verbatim Diskettes 8 S.S.0.D. IS yrs warranty) rte 11P436 270 Send SAE for details. 07373 10 4539 N.B. Carriage Is alts on all Disk Drives and Peripherals I ETI AUGUST1983 5 COIN/TECH ELECTRONICS

130132 253708 100L6A747 50p 51101 red NEWESED 4ett 7p 651/151111112121 80135 3apMJS3055 253771 111748 3503mm green 100 EIKI IA T02 Electrolytic. radial SC10711 130136 300MPSA05 2N3772 1701871458 36o5inrn green 7805 3135 7905 40p Vehm/VoSe Mee IfelueNotte Mme BC100C 80137 30o8775806 2N3773 190p 1.1.11496 70p3mm yellow 10p007812 7912 I/C109C MPSA12 509 fuF/63 tto 22/25 150 00138 350 2N3819 20pLM900 47p5rnrn yellow 10p7815 3800 2.2u0/133 Op SC113/4 80139 359MPSA13 253866 90pMC13455 retangular 509 4700uFvF /25 239 OC11516 MPSA14 AZ: 4.700/63 Op 1000u0/25 320 SP 50140 35p 253903 10pMC1458 340Slackatile 78105 30p 79105 4Sp 10uF/63 79 SC117 80 8172 640MPSA42 2N3904 10pMC1496 7pRED 10078112 309 791.12 559 100uF /63 Op MPSA43 GREEN 14p 20p 22uF/16 SCii9 OP 802006 040 2N3905 10pMC3302 702p 78115 300 791.15 5550 4 7uF/25 Op 47uF/16 60 SC139 83222 253906 MC3401 680YELLOW 130 Sep 10uF/25 EP 100uF/16 99 S C140 80239A 40oMPS463 2 2144030 30p0p MC3403 659 FT, 78505 51/ at 54 5400 22uF/25 220uF/16 120 e ctei s MPSA64 22254033 MC3456 60 e 80239C 500 30o 460 pin 70LM3096 50 41 14 120p 47uF/25 fp 4700F/161179 802404 1.11115492 2144007 SC143 420 40pNE529 220o14 pin asLM3176 40/1 54 240 100uF/25 10p 1000a/10 19P O C1502/ 80240C sop710993 2 254058 NE532 80p16 pin 17.1317T /10/14 100uF/10 71029A 99 989 60 2200uF/10 350 oo 802414 50o 254061 109NE544 200018 pin 1 1 LM337T AdUl A 2009Tantulum lased. T1P298 3 2144062 NE550 BC169C S P 002424 520 0p 170p20 pin 14pp110723C5 44, 35p Vslue/Volt Pries Wee/Volts P710. oo 8D2434 50o711729C 254400 14pNE555 1 S C120 22 pm 14p 87.1 0.1u0/35 120 6800/25 209 SC17i op 802430 080 1111.30.4 254401 14pNE556 45024 pin flp 4082 0.220F/35 120 op EID2444 0007103011 254402 14pNE558 10uF/16 209 SC172 viewc 330 28 pin 1 Sp 000 12p 4093 It: 0.334F/35 120 709 30o254403 14pNE564 1 120 4098 72p O G173 SP TIP314 40 on 0.33uF/35 150/16 280 300 330255401 18pNE565 140p 001001 14p 4510 460 0.471/F/35 129 22.0/18109 BC179C 80181170 300T103113 330255457 269NE566 150p REFIT, FRS 5 44p W 40p 4511 0.68uF/35 120 BCI79 902 30971031C 37p255458 259NE567 120p18/ 11Ip 15p 512 42 10F/35 120 F,'ISOOP BCI82 90 BF 143 30p717324 330255459 25pNE570 37 10/1000 i 120 4514 1109 TIP32B 200. 2 2uF/35 18p Nd'36968F/6.3 600 SC1821. op BF'S. 300 330255460 NE57I 350900 14/2000 2229 2 159 4516 71P32C SOP a 3oF/35 109 100u0/63 609 80184 aBF185 16p7 37p255550 190NE594 220p14/400V 24P 013 220 4520 SOo 4 7uF/25 200 10000/3 409 SC 1841 ElF194 12 111747 5p255551 NE644 380014/600V 280 014 TiP110 'NE645 400 89Cerra419 miniature Mate. BC212 00195 12p 4589256027 It: 270p10/8000 320015 :ggg 450P1 8pF to 470000 Sp MM. 602171 Op00196 129710115 45.256028 2 51490 3100039/500 400016 22p 4556 400Cmmlo OW 839: 1041, 225.175 49 immix B C213 op SF197 12pVW, 20 F 5576018 34/100V 429017 350 4584 340 13C2131. Op 8E198 11290p111,121 700 15p5576115 190 34/200V 44p020 42p 4585 589 SC214 ElF1 710122 700556 4395576660 90964/50V 75p 021 40P S C2141 8F24499C 229710126 70 741C 14pt13.4120S 70#64/1000 800022 44p sisTu .s sr n BC237 oo 8E245 gp°7470 500TBA800 70p64/2000 023 224 series 57. tolerance. 10 ohms to 1 M 1p each. 40p/100 BC238/9 'op 8F256C 42955 748C 78810 7950p 024 38p4pone value tt:TIP3055 TBA820 64/4000 949 1,11/Carboni,. E12 series 50v tolerance. 10 ohms to I M20 immix 1400/100 B C25 i icy, 80257 320 7700pCA3089 1750; 0100E5 025 4p ISC300 4op 00254 320 20pCA30900 3009T041022 026 711p 715900 TDA1024 9P Melt 1nm 624 series 1S tolerance. 10 ohms to 1144peoeh. 250p/100 S C301/2 oop 80259 359 240CA3140E t 1r0447 027 220 BF336 71592 CA3160E 1040p4p 1042002 99 one value BC303/4 360 20p 0490 1p 28 40p BC307 10080337 3902141613 300CA3161E 155pTDA2003 ;4% 29 430ORDERING: All components top quality and 108 spec. Plow add 400 W3 251711 CA31896 245pTDA2020 0491 e Caome 40o 30p 80 30 1 SpPIP to all orders below CS slid VA r to total. GovemmeM eider. BF45738 329251893 280CA3240E 1109TDA2030 0495 040 409 S C327 4.0 04200 80 trepeplenotore. Send cimquit or postslordor nwde Pm, 4F458 3202522188 2.0p10351 450T1061 400 041 440stile to Comteen Elisetronles. All orders deepatehed seine day. Send 00328 130459 3692522194 23010353 11081 A202 81, 042 809 42p1401. SAE for fun ',deafen. - SC337 /2200 BF 829 2N222 LF355 51 BAX13 SP 12p 28o 209 85p 46 489 BC338 1110 830 2142222 flp10356 8130 84X16 7p 280 289 5921 48 300COMPONENT PACKS IOC413C BF 880 2692522224 20010357 C1160 70p144 6p 9 200CP2 10 BC182 6 10 BC212 Transistors 1300 FREE! SC414C 2142368 239LM30 I curio 90p1$ 7p050 209CP3 10 8C549 8 10 BC559 Translate's 130p OC415C fiFBF 885 159 254444 15910 2592523694 LM307 54p 1N916 051 440CP7 100 15914 switching Medea 100V 240p WITH ALL BC416C 10010p BF 887 2702142484 1713115 00255061 30 tIC477 240 250154148 068 14pCP8 100 171916 switching diodes 1004 300p 23p BF X118 239252904 200La1311314 1200p255062 3p069 14pCP9 30 1714002 14/100V rectrhers 100p 81C470 154149 ORDERS BFY0 2302529044 22o17,1324 40p N 4 32 070 14pCP10 100 154148 swtiching Medea 1500 BC479 13200 Ti 154001 tr. BF5551 252905 220L70339 401, 154002 071 140CP16 50 rri.ed electrolytic capacitors 3600 SC54 100B7 2202142905A 25oLM348 609 550 40072 149CP17 4 LF351 JFET Op Amps (low noise! 1700 OVER £6 SCS47613 154003 4p 911 880055353552 2110252906 17/358 440C225D 09 073 14pCP18 4 10353 JFET Op Amps (wide band) 3009 B C54813 Op 8.55954 154004/5 Sp 2302529064 22p20p 187376 669C226D 7600 154006/7 75 140CP21 20 Red rectangular Lees DUAL BC549C BU205 40o252907 23pLM 380 CapC2360 909 OP 077 140CP28 10 C1061) 44/400V Tnyristors 114 O 0553C 9U206 143p.2529074 259LM382 120pBA1 00 30p 11115401 11p078 149CP29 25 5mrn Red Leda with 19Sp t OOpp 155402 c Gheipe TIMER IC SC5 253053 230187384 125p ENFOS 081 129CP3025 3mrn Red Leds won 1700 EIC557568 110 MJ2955 253054 155402/4 3p 1180 569187386 850 155005/6 e pssas 118JE3 40 4110253055 5001/0387 130p21/736V Op 14p NE558 S C5492 90 ....mat 7c9253441 1209171388 170913W 155007/8 15p INC560C ICO MJE37 8402143442 187389 150p3V9 -51V 12 64/100V 28p SCV70 NME520 1109253702 100LM393 709 1.F Os 64/200V 30p S CV7, '80 MJE521 fiSo253703 10p04701 32p 60/4004 32 O CVOD17215 1SOP7P MJE2955 1100253704 10p187741 14p 64/6000 350 2.13704 10pL71711 Sop COMTECH MAIL ORDERS * FAST RELIABLE SERVICE * 205 STURDEE ROAD ELECTRONICS LEICESTER LE2 95Y * VERY COMPETITIVE * Telephone 105331 779578

Sub Min PULSE TRANSFORMER. Sac centre tap- 9" MONITOR in attractive case. Non Standard ped. Suited, for Thyristor triggering 20p each. 10 Input. With Into En each. Carr £7. Matching ACSII off CIAO. coded Ouerty Keyboard with Numeric Keypad and RAPID DISCHARGE CAPACITOR 8 mfd 4KV 5 27 Function Keys. E25 each P&P £5. The Palr £40. each P&P 0. CLEFELECTRONICMUSIC Carr £7. 12"MONITOR. Cased. Non Standard Input. With TELEPHONES. 706 style black, blue, green, grey, InfOrE2041aCh. Carr C7. With Matching ASCII coded 25.50 each. 10 off £45. Ouerty Keyboard with Numeric Pad and 24 Function Discoloured £4 each. 10 off CIO. 746 style black or MICROSYNTH Keys. £35 the Pak. Carr £7. grey 0.50 inch. Pep 12 each. 4-10 units 5. Over 2/i Octave Music Synthesizer with two Oscil- POWER UNIT. 240V Input. Outputs +5V/15A 10 by arrangements. lators,two Sub-Oots, Switched Routing and +24V/1.54; -24V/3A £12 each. TOKIN NOISE FILTER VG215FU. 250VAC 15A Thumbwheel. A comprehensive instrument offer- INSTRUMENT CASE standard 19" width x 16" 50 /80HZ. With fixing . New a each. ing the to range of Synth. Music 8. effects. depth x 10- high. £5 each. Carr £7. FLOPPY DISK DRIVE 8" by MEMOREX. Connection VU METER. Scaled 0-5, size 11 x 7/8", 50p each FULL KIT £137 Also available in 3 parts. details. £85 each P&P £5. 10 off C4. CREED 75 TELEPRINTER. Very good con I.T.T. LOUD SPEAKER. 3 1" die. 50 ohm 0.2 Watt. PERCUSSION dition. 225 each. Carriage £7. New. Pip each. 10 off ,13.50. E.H.T. CABLE. Overall die 5mm, 10p per metro. 1 ELECTROLYTIC CAPACITOR 15,000 mfd 25V. 100 metre drum 5.50 P&P £4. MICROSYNTH t 20p ea. 10 o821.80. Multi Colour RIBBON CABLE 10 way, 50p per TwoChannel touchSensative unit plus SLOTTED OPTO SWITCH with data 50p. 10 off metre, 10 metres U. 14 way 75p per metre, 10 variable angle L.F.O., phaser, internal 24. metros DI. 140 metres 50. and external triggering. NFRA RED QUARTZ LAMP 230V 620 Watts. ILLUMINATED ROCKER SWITCH. 2 pole 250V 8 FULL KIT £121 Size 131/2 x1/4" die 21.50 ea. 10 off £10. Amp, orange, 50p each. 10 off £4. FERRANTI PHOTOCELL type M915 - 50p ea. JOYSTICK SWITCH 4 directions, 13 each. P&P PROGRAMMABLE 10 off 24 12. BAN D -BOXBACKING TRIO AMPUFIER BOARD complete wth heat sink .52 PCB KEYBOARD PAD. 19 push contacts, 0-9; A -F !output transistors type 2N5293. 12/24V Input. At plus 3 optional, 5.50 each. 10 off C12. THREE PIECE BACKING BAND least 5 Watt output. Circuit supplied £1.50. KEYBOARD PAD. 12 Alma Reed Switches, push Generates the sounds of three instrumentalists VARIAC 2 amp. Ex-eq. Good condition £12 ea. to make, 0-9; *; Et Blink, size 3 x.21 x 2" high, £4 to back Soloists P&P £4. e ach. 10 off £15. P&P £3. LED type TIL209 Red with holder - 8p ea. 10 EPROM 2716 Single re0, 01.50 each, 2564 £4 DRUMS + BASS + KEYBOARDS off 70p Over 3,000 chord changes (60 scores) on 132 dif- I.C. SOCKET 16 pin- Bp ea. 100 off 28. SPECTRAL RELIANCE TEN TURN POT. 100 ohm ± 1%. Brand new, 75p each 10 off CI. ferent chords -extendable to 200 scores. Master GEARED MOTOR 117/234 Volt Input 50112. 4" die- SUDER POTENTIOMETER. Twin Gang, 200K or Rhythm also.requi red. x 5 1" deep, 1" shaftNew C5 each P&Pt4 2M, 257 each 10 off 53. FULL KIT £235 EXTENSION £82 MOTOR 12V DCInput. 3" diex 41- dep,e 1" PANEL MOUNTING FUSE HOLDER for 1 1" fuse, shaft. Now 13.50 each POP CI. 20p with. 10 off (1.50. DC MOTOR 8-12 Volta.Mechanical Constant B EUJNO LEE CHASSIS MOUNTING FUSE ZrrControl 1 1" die. tl,sech. HOLDER for 1 1" fuse, 15p each. 10 off £1. 12V DC with pudey & semi -conducts I.E.C. MAINS LEAD. 2 metre length, heavy duty, 88/72 NOTE PIANOS rudc4noontrgatl each. 110p each. 10 off 5. US MOTOR 2 Phase 9 volt AC. 375 4 CORE CURLY WIRE extending to 2 metres, 20p SPECIALISTS SINCE 1972' RPM. Good torque (needs 30-40 mid capacitor. e ach, 10 off 5.00. Using Patented electronic technique to give advanced Omuta - Suitable for Robitice/Motters etc. n each. MICROPHONE/EARPIECE INSERTS. Brand Pon of Piano Key Inertia. OTHER SYNCHRONOUS/STEPPING MOTORS new. 750 each. 10 off 5. AVAILABLE. PLEASE ENQUIRE EXECUTIVE TELEPHONE -PUSH BUT- COMPONENT KITS GEARED MOTOR 120V 50HZ. 4Watt 1 rpm. 2" dia TON.Functionsinclude10 number including Keyboard x 11" deep. moo each. memory; repeatdialing;internalMic- 88 NOTE £266 CENTAUR FANS 41", 115V New, (AM each. rophone & Speaker and separate handpet 72 NOTE £234 MUFFIN 115V 41", unused, CS each P&P O. etc. Will connect direct to British Telecom The above may also be pur- TRANSFORMERS - AN brand new, 240 vats chased in four parts. Input. System. BRAND NEW. ONLY £25 ea. MASTER RHYTHM St 26.5V 2.5A. Size 31 x 21 x 21".12.50 each. P&P£4. Sec 115V1A (auto) tta each. Sec 6V 1.66A 5.50 PUSH BUTTON TELEPHONES for Inter- DOMESTIC KITS PROGRAMMABLE DRUMS Es. 12V 100MA 50p each. nal Systems. BRAND NEW. P&P £2 ea. inc. Cabinet, RA., & Spkr. Twenty -Four Rhythm programm- TRANSFORMER 120 Volt Input. Sec 10-0-10V 1A 746 style Two Tone Grey £8 each. 88 NOTE £442 able Drum Machine with twelve 715 emdt KRONE type FeTAp 731. Beige. £6 ea. 72 NOTE £398 instruments. Eight sections are ex- Sub MI TRANSFORMER 0-120-240V Input. Sec Quantity discount - Please Enquire tended to 24/32 measures for two 124-12V 4VA 75p each 10 off bar programming. Sequence opera- TOROIDAL TRANSFORMER 0-115-230V Input. Minimum Order of Goods O. Minimum PCP STAGE MODEL Sec 13.541-13.15V 8VA. 5.50 each 10 off C12 5E0. VAT at 16% MUST be added to TOTAL OF tion and instrument tone adjust. inc. Cabinet & Stand COMPLETE KIT £79 TOROIDAL TRANSFORMER 0.120-240V Input. GOODS Et PACKAGING. 72 NOTE £383 Sec 0-12V; 0-12V IOVA per winding. Encapsulated. Many more components and teat equipment fA sods. 10 offal. zwelIeble. S.A.E. or telephone for Date. STRING ENSEMBLE £198.50 ROTOR -CHORUS £98.00 ALL.e PRICES INC.cVri C4,24.&pc,za..,m_Amcpcveksi STEWARTOFREADING SQUARE FRONT KEYBOARDS 88 NOTE £60 49 NOTE £29 man 1111 WYKSMIA ROAD, READING, BERKS. ROE 1PI. T.F,(TTOUI .E S IEJ ;L,F' I. 71 73 NOTE £50 30 NOTE £19 STITTIAM,ALL LANE STTUIFi KEYSWITCH ITEMS ALSO AVAIL- T.1 1073111141 CTIF,T111 T Ceders welcome 9 am -5.30 pm Monday to Saturday Inclusive TEL Oh 1411, 1297 ABLE

6 ETI AUGUST 1983 T.V. SOUND TUNER BUILT AND TESTED In the cut-throat world of consumer electronics, one MAKE YOUR of the questions designers apparently ponder over is "Will anyone notice if we save money by chopp- OWN P.C.M. & ing this out?" In the domestic TV set, one of the first casualties seems to be the sound quality. Small speakers and no tone controls are common FRONT PANELS £24.95 + £2.00p&p. and all this is really quite sad, as the TV companies do their best to transmit the highest quality sound. Given this background a compact and independent TV tuner that connects direct to your Hi-Fi is a must for quality reproduction. The unit is mains -operated. This TV SOUND TUNER offers full UHF coverage with 5 preselected tuning controls. It can also be used in conjunction with your video recorder. Dimensions: 115"x 8%"x 3%" E.T.I. kit version of above without chassis, case and hardware. £12.95 plus £1.50 p&p. PRACTICAL ELECTRONICS STEREO CASSETTE RECORDER KIT W. HP ONLY £31.00 plus £2.75 p&p. NOISE REDUCTION SYSTEM. AUTO STOP. TAPE COUNTER. SWITCHABLE E.O. INDEPENDENT LEVEL CONTROLS. TWIN V.U. METER. WOW & FLUTTER 0.1%. RECORD/PLAYBACK I.C. WITH ELECTRONIC SWITCHING. FULLY VARIABLE RECORDING BIAS FOR ACCURATE MATCHING OF ALL TYPES. Kit includes tape transport mechanism, ready punched and back printed quality circuit board andel' electronic parts. is. semiconductors, resistors, capacitors, hardware, top cover, printed scale and mains transformer. You only supply solder & hook-up wire. Featured in April P.E. reprint 50p. Free with kit. STEREO TUNER KITSTEREO CASSETTE This easy to PHOTO RESIST KIT (Ref: HB2) build 3 band Complete kit containing artworkPCB, stereo AM/ DECK and all necessary FM tuner kit Stereo cassette process materials is designed NORMAL REC. PRICE £24.60 in conjunction tape deck trans- with P.E.IJuly port with elect- UV EXPOSURE UNIT (Ref: UV1) '81). For ease of construction and alignment ronics. Manufacturer's Perfect results everytime. Kit contains: Lamp, Holder & it incorporates three Mallard modules and an surplus - brand LC, IF System. new and operat- Shade together with full instructions for DIY Unit which FEATURES: VHF, MW, LW Bands, interstat- ional - sold ion muting and AFC on VHF. Tuning meter. without warranty. offers PCB, Precision Photo, Label & Panel manufacture Two back printed PCB's. Ready made chassis NORMAL REC. PRICE £27.60 and scale. Aerial: AM -ferrite rod, FM -75 or £11.95 300 ohms. Stabilised power supply with 'C' plus £2.50 p&p. core mains transformer. Alt components supp- UV EXPOSURE UNIT AND ARTBOX (Ref: UV2) lied are to P.E. strict specification. Front scale Just requires A portable ready made unit containing two 8 watt UV tubes size 10%"x 2%" approx. Complete with dia- gram and instructions. mains transform- giving a 6" x 9" exposure area which may also be used as a er and input/ light box with the UV filter supplied. SPECIAL OFFER! £13.95 +£2.50 p&p. output sockets Self assembly simulated wood cabinet sleeve and a volume tosuit tuner only. Finish size: 11%"x8)4"x3%". control to com- NORMAL REC. PRICE £64.60 £3.50 Plus £1.50 p&p. plete. Supplied with full connection details. FOTOTOOL KIT (Ref: HB3) Containing artwork, film and all the necessary process 125W HIGH POWER materials required for professional quality labels and panels. CAN ALSOBE USED TO PRODUCEPRECISION PCB PHOTOMASTERS AMP MODULES The power amp kit is a module for high NORMAL REC. PRICE £23.10 power applications - disco units, guitar amplif- OFFERS VALID UNTIL AUGUST 31st 1983 iers, public address systems and even high power domestic systems. The unit is protected exiii Inn 1ME 1M MI III= MI against short circuiting of the load and is safe Please send me the following as quickly as possible in an open circuit t ondition. A large safety SPECIFICATIONS: margin exists by use of generously rated com- Max. output power IRMS): 125 W. Operating ponents, result, a high powered rugged unit. voltage (DCI: 50 - 80 max. Loads: 4-16 ohm. QTYDESCRIPTION Price Ea. TOTAL The PC board is back printed, etched and Frequency response measured @ 100 watts: ready to drill for ease of construction and the 25Hz - 20KHz. Sensitivity for 100w: 400mV aluminium chassis is preformed and ready to I PHOTO RESIST KIT (HB21 £21.50 £ : @ 47K. Typical T.H.D. @ 50 watts, 4 ohms: use. Supplied with all parts, circuit diagrams 0.1%. Dimensions: 205x90 and 190x36mm. UV EXPOSURE UNIT (UV1) £24.00 £ : and instructions. ACCESSORIES: Stereo/mono mains power supply KIT £10.50 BUILT £14.25 UV ARTBOX(UV2) £58.00 £ : I kit with transformer: £10.50 plus £2.00 p&p. +£1.15 p&p +£1.15 p&p. FOTO TOOL KIT (1-183) £20.00 £ : I TOTAL £ : I AUDAX 8" SPEAKER BARGAINS (Cheques or Postal Orders only HIGH QUALITY 40 WATTS 2 WAY 10 WATT Iplease for Special Offers). Cheque/PO : RMS BASS/MIDRANGE Ideal for either Hi-Fi or Disco use this speaker SPEAKER KIT Please send full catalogue Price includes VAT & Carriage. features an aluminium voice 8" bass/mid range and 3%" I coil a heavy 70mm diameter tweeter. Complete with screws, Name magnet. Frequency res: 20Hz £5.95 wire, crossover components 1 to 7KHz. Impedance: 8 ohms. +£2.20 P&P. and cabinet. All wood pre- Address cut - no cutting required. AUDAX 40W Ferro -Fluid Hi-Fi Finish - chipboard covered Tweeter wood simulate. size 14%"x I X/over on 5kHz 83'."x 4". PAIR for ONLY I - 22kHz. 60mm £5.50 square. 8 ohm. +6013 p&p. £12.50 plus £1.75 p&p. I a division of I All mail to. ALL CALLERS TO: 323 EDGWARE ROAD, I KELAN ENGINEERING Ltd 21E HIGH STREET, ACTON, W3 6NG. LONDON W2. Telephone: 01-723 8432. Hookstone Park (5 minutes walk from Edgware Road Tube Station) Note: Goods despatched to U.K. postal address. only. Now open 6 days a week 9 - 6. Prices include VAT. I Harrogate, N. Yorks All items subject to availability. Prices correct et I 31 /5/83end subject to change without notice. Please allow 14 working days from receipt of order complete P.C.B. workshop for despatch. RTVC Limited reserve the right to up. ETI /8/83 dote their products without notice. All encluldol and R oir mum voriom Immo um mum En mum V' S.A.F.- Telephone -or snail orders by ACCESS welcome.

ETI AUGUST 1983 BK ELECTRONICS MULLARD SPEAKER KITS dt80 LOUDSPEAKER Purposefully designed 40 watt R.M.S. end 30 Prompt Deliveries watt R.M.S. B ohm speaker systems recently The very best in quality developed by MULLARD'S specialist team In and value. VAT inclusive Belgium. Kits comprise Mulford woofer 18" or Ported tuned cabinetinhard- VI with foam surround and aluminium voice cad. wearing black vynide with protec- prices Mallard 3' high pares domed tweeter. B.K.E. NM and tested crossover based on Mullard tive corners and carry handle. Built Audio Equipment circuit, combining low loss components, glass and tested, employing 10in British fibre board and recessed loudspeaker terminals. driver and Piezo tweeter. Spec: 80 Test Equipment SUPERB SOUNDS AT LOW COST. Kits supplied watts RMS; 8 ohms; 45Hz-2OKHz; in polystyrene packs complete with instructions. by r 40W system - recommended cabinet size 240 Size: 20in x 15in x 12in; Weight: x 216 x 445rtim 30 pounds. Dander Price £14.50 each + E2.00 P et P. 5' 30W system - recommended cabinet size Price: £49.00 each and 160 x 175 x 295mrn £90 per pair Price E13.90 each + E1.50 P 8 P. Carriage: £5 each £7 per pair Leader Designer approvedflatpack cabinetkits, including grB fabric. Can be finished with iron on HOBBY KITS. Proven designs including glass veneer or self adhesive vinyl etc. 8" system cabinet kit E8.013 each + £2.50 P'Er P. frOAktTEICfibre printed circuit board and high quality 5" system cabinet kit E7.00 each + f2.01:1P ES P. components complete with instructions. FM MICROTRANSMITTER (BUG) 90/105MHz with very sensi- tive microphone. Range 100/300 metres. 5 x 46 x 14mm (9 volt) STEREO Price: £7.99p DECK MODULE DIGITAL THERMOMETER -9.9"C to +99.9"C. LED display. Com- Comprising of a top panel and tape mechanism coupled td plete with sensor. 70 x 70 mm (9 volt) Price: £27.60p a record/play back printed board assembly. Supplied as one complete unit for horizontal installation into cabinet or 3 WATT FM TRANSMITTER 3 WATT 85/115MHz varicap con- console of own choice. These units are brand new, ready trolled. professional performance. Range up to 3 miles 35 x 84 x 12 built and tested. mm (12 volt)Price: £12.49p Features: Three digit tape counter. Autostop. Six piano type keys, record, rewind, fast forward, play, stop and SINGLE CHANNEL RADIO CONTROLLED TRANSMITTER/ eject. Automatic record level control. Main inputs plus RECEIVER 27MHZ Range up to 500 metres. Double coded mod- secondary inputsforstereo microphones.Input Sensitivity: 100mV to 2V. Input Impedance: 68K. ulation. Receiver output operates relay with 2amp/ 240 volt Output level: 400mV to bothleft and right hand contacts. Ideal for many applications. Receiver 90 x 70 x 22 mm 9/ channels. Output Impedance: 10K. Signet to noise ratio: 45d8. Wow and flutter: 0.1%. Power Supply 12 volt) Price: £16.49 Transmitter 80 x 50 x 15 mm (9/12 volt) requirements: 18V DC at 300mA. Connections: The Price £10.29 P&P All Kits +509. S.A.E. for complete list. left and right hand stereo inputs and outputs are via 3 watt FM individual screened leads, all terminated with phono plugs (phone sockets provided). Dimensions: Top Anal 51in Transmitter x111in. Clearance required under top panel 21in. BSR P256 TURNTABLE Supplied complete with circuit diagram and connecting P256 turntable chassis S shaped tone arm diagram. Attractive black and silver finish. Belt driven Aluminium platter Price t11.70 + £2.50 postage and packing. Precision calibrated counter balance Anti - Suppiementarypartsfor18VD.C.powersupply (transfoimer, bridge rectifier and smoothing capacitor) skate (bias device) Damped cueing lever 240 volt AC operation(Hz) Cut-out template supplied Completely manual arm. This deck has a completely manual arm and is LOUDSPEAKERS designed primarily for disco and studio use THREE QUALITY POWER LOUD- where all the advantages of a manual arm are SPEAKERS (15", 12" and 8" See 'Photo). Ideal for both Hi-Fi and Disco applica- required. tions. All units have attractive cast alu- Price £31.35 each. £2.50 P&P minium (ground finish) fixing escutcheons. Specification and Prices. 15" 100 watt R.M.S. Impedance 8 ohms. POWER AMPLIFIER 50 oz. magnet. 2" aluminium voice coi I. Res. Freq. 20 Hz. Freq. Resp. to 2.5KHz. Sens. MODULE NEW OMP100 Mk.11 POWER AMPLIFIER 97dB. Price: £34.00 each + £3.00 P&P MODULE Power Amplifier Module complete withintegral heatsink,toroidal transformer 12" 100 watt R.M.S. Impedance 8 ohms. power supply and glass fibre p.c.b. assembly. 50 oz. magnet. 2" aluminium voice coil. Res. Incorporates drive circuit to power a compatible Freq. 25Hz. Freq Resp. to 4 KHz. Sens. LED Vu meter. New improved specification 95dB. Price: £24.50 each + £3.00 P&P makes this amplifier ideal for P.A., Instrumental 8" 50 watt R.M.S. Impedance 8 ohms. 20 and Hi-Fi applications. oz. magnet. 11/2" aluminium voice coil. Res. SPECIFICATION Freq. 40Hz. Freq. Resp to 6 KHz. Sens. Output Power:- 110 watts R.M.S. 92dB. Black Cone. Price: £9.50 each. Also Loads:- Open and short circuit proof 4/16 available with black protective grille Price: ohms. £9.99 each. P&P £1.50. Frequency Response:- 15Hz - 30KHz -3dB. 12" 65 watt R.M.S. McKENZIE C1285GP (LEAD GUITAR, KEYBOARD, DISCO) 2" T.H.D.:- 0.01%. aluminium voice coil, aluminium centre dome, 8 ohm imp., Res. Freq. 45Hz., Freq. S.N.R. (Unweighted):- -118dB ±3.5dB. Reap. to 6.6KHz., Sens. 98d8. Price: £22.00 + E.3 carriage. New model. Sensitivity for Max Output:- 500mV @ 10K. 12" 86 watt H.M.S. McKENZIE C1285TC (P.A., DISCO) 2" aluminium voice coil. Twin Size:- 360x 115 x 72 mm cone. 8 ohm imp., Res. Freq. 45HZ., Freq. Resp. to 14KHz. Price 1:22 + £3 carriage. r Improved specification Price:- £31.99 + £2.00 P&P. 15" 150 watt R.M.S. McKENZIE C15 (BASS GUITAR, PA.) 3" aluminium voice coil: Vu Meter Price:- £7.00 + 50p P&P. Die cast chassis. 8 ohm imp., Res. Freq. 40Hz., Freq. Resp. to 4KHz. Price: E47 + E4 carriage. HOME PROTECTION SYSTEM Better to be 'Alarmed' then terrified. PIEZO ELECTRIC TWEETERS - MOTOROLA Thandar's famous 'Minder' Burglar Alarm System. Join the Piezo revolution. The low dynamic mass Ino voice coil) of a Superior microwave principle. Supplied as three units, Piezo tweeter produces an improved transient response with a lower completewith interconnection cable.FULLY GUARANTEED. distortion level than ordinary dynamic tweeters. As a crossover is not Control Unit - Houses microwave radar unit, range required these units can be added to existing speaker systems of up up to 15 metres adjustable by sensitivity control. to 100 watts (more if 2 put in series). FREE EXPLANATORY LEAFLETS Three position, key operated facia switch - off - test SUPPLIED WITH EACH TWEETER. - armed. 30 second exit and entry delay. Indoor alarm - Electronic sweptfreq.siren. %Curry TYPE 'A' IKSN2036A13" round with protective 104dB output. wire mesh, ideal for bookshelf and medium Outdoor Alarm - Electronic swept freq. siren. 98d8 sized Hi-fi speakers. Price £4.29 each. output. Housed in a tamper -proof heavy duty metal .j TYPE 'B' (KSN1006A1 3 Y2" super horn. For case. general purpose speakers, disco and P.A. Both the control unit and outdoor alarm contain re- chargeable batteries which provide full protection systems etc.Price £4.99 each. during mains failure. Power requirement 200/260 Volt TYPE 'C' (KSN6016Al2" x 5" wide dispersion AC 50/60Hz. Expandable with door sensors, panic horn. For quality Hi-fi systems and quality buttons etc. Complete with instructions. discos etc. Price £5.99 each. SAVE OVER £100 Usual price £228.85 - B.K.E.'s BARGAIN PRICE £128.00 TYPE 'D' IKSN1025A1 2- x 6" wide dispersion + £5.00 P&P. horn.Upper frequency responseretained S.A.E. for colour brochure. extending down to mid range 12KHz). Suitable TYPE 'C' for high qualityHi-fi systems and quality discos. Price £7.99 each. - SAFGAN DT -620 DUAL TRACE OSCILLOSCOPE. New TYPE 's (KSN1038A) 3%" horn tweeter with British model. 12 month guarantee. 20 MHz Band Width. attractive silver finish trim. Suitable for Hi-fi Specification: * CH1. CH2: 5mV/div-20V/div. * Time Base: 1 Sec/div-10Ons/div. * XY Facility: Matched XY monitor systems etc.Price £4.99 each. inputs. * Trigger:Level control ± slope selection. TYPE 'F' IKSN1067A! Cased version of type * Auto, normal, TV Triggering. * -Modulation. * CAL out- 'E'.Free standing satellite tweeter. Perfect put 1V 1 KHz. * Sweep output 0-9V. * Graticule blue ruled add on tweeter for conventional loudspeaker 10 x 8 cm. (5" C.R.T.) Very sharp trace. * Size: H235mm, systems. Price £10.75 each W177mm, D360mm. * Weight: 6.5 Kgs. * Supply: 200-240 .. V.40-60Hz. *Price:£241.50 - FREE Securicor P&P MA ea. for SAE for Piezo leaflets). e-1) Delivery. Probes: X1 £8.05, X1/X10 Switched10.93. _ - FREE SECURICOR DELIVERY TYPE 'E' TYPE 'F" B.K. ELECTRONICS 17-^7 MINIM '018 VISA UNIT 5. COMET WAY. SOUTHEND-ON-SEA. ESSEX. SS2 6TR

. prior

8 ETI AUGUST 1983 INTEINAINNAII 64K DRAM A little short on memory? ETI comes to the rescue with this project which is just the ticket for 6502 or 6800 based systems. Latching it into your system just couldn't be easier, because the DRAM board uses an EPROM to do the address decoding. No more lash -ups, just program the PROM to define where the memory

goes in the micro's space. Why didn't we think of it before? Smart NiCad Charger Now there have been plenty of NiCad chargers that have graced these pages - but this one will automatically rejuvenate worn out cells. (Wonder if it would work on the cells in the Editor's brain?) New Series: Audio Design John Linsley Hood is one of the best known audio designers, and he'll be guest -writing this series for us. The emphasis will be on practicalities, with easy -to -follow explanations and simple but useful calculations. Although as little as possible be assumed about the level of expertise of the reader, there will be something here for even the most experienced of you. Audiophile review The Videotone Minimax speakers have provided a touch -stone in price -effective audio for many years. Now there's a Mark II version- can it be as good, or, possibly, even better? Our intrepid Audiophile investigates. The Digger No, nothing to do with our Australian colleagues, but a useful little device for digging around inside digital circuits - a logic oscilloscope trigger. The idea is very simple, really, all you do is. . .but ALL THIS AND MORE IN THE SEPTEMBER ISSUE OF ETI, ON if we told you that, you might not buy next month's mag, mightn't SALE AUGUST THE 5th. PLACE YOUR ORDER NOW, OR you? RISK MISSING OUT! Articles described here are in an advanced stateof preparation. However, circumstances may dictate changes to the final contents.

ETI AUGUST 1983 9 POWERTRAN COMPUTING TODAY ELECTRONICS TODAY INTERNATIONAL

COMBINE THEIR TALENTS TO BRING YOU SELF- ASSEMBL KIl CORTEX £295 VAI ARRiAGE FREE

MASSES OF SOFTWARE Pascal, Forth, Mdex, Nos, Meta CP/M compatible ()Basic, SPL, Window, Spell + range of business packages. Please contact: Microprocessor Engineering Ltd, 21 Hanley Road, Southampton SO1 5AP 0703 775482

i6 Sr, Mnro Cconpu a.*

SOH IOU AMP. &ANC READY 0 BUILT

wrt R T y U105 £395 VAI S O Se 4 H J K S. CARRIAGE FRE I C H ItA

OPTIONAL EXTRAS RS232C interface kit £9.20 Floppy disc interface £86.50 Pair of 51" disc drives& hardware kit .X356.00 READY BUILT CORTEX WITH OPTIONAL DISC DRIVES FITTED CORTEX B - Basic machine + RS232C E410.00 CORTEX C - As above + disc drives 0815.00 16 BIT COLOUR COMPUTER All items carriage free - prices exclusive of VAT ALL THESE FEATURES PROVIDED AS STANDARD! High speed 24K byte extended basic interpreter Assembler Et Disassembler Powerful TMS9995 16 bit microprocessor Auto line numbering facility 48 bit floating point gives 11 digit accuracy Full renumber command High resolution (256 x 192) colour graphics Simple but powerful line editor Memory -mapped video controller for 3D simulation Buffered i/o allows you to continue executing the Independent 16K video RAM program while still printing 16 colours available on the screen together in Flexible CALL statement allows linkage to machine Graphic mode code Fast line drawing and point plotting basic commands routines with upto 12 parameters High speed colour shape manipulation from basic Basic programs may contain spaces between keywords Full textural error messages to make programs readable without using more memory String and Array size limited only by memory size 64K RAM using latest technology 64K DRAMS Real time clock included in basic Over 34K bytes available for basic programs even when Interval timing with 10mS resolution via TIC function extended basic includes IF -THEN -ELSE Named load and save of basic or machine code programsSupports up to 16 output devices Auto -run available for any program Screen and cassette included as standard Powerful machine code monitor Supports bit manipulation of variables from basic Error trapping to a basic routine included ULTRA POWERFUL 24K BASIC Basic supports Hexadecimal numbers

COMMANDS LOG KEY ? RANDOM SGET RUN SOR ENTER MAG SIZE SYS STATEMENTSUNIT LIST TOF To: Powertran Cybernetics, Portway Industrial Estate, CONT TIC IF BAUD PURGE TON MON SON ELSE CALL NUMBER DIM Andover, Hants. SP10 3NM. 0264 64455 BIT ON DATARENUM DEF FUNCTIONS CRB GOT() READ BOOT NEW Please send me ABS CRF GOSUB RESTOR GRAPH END ADR MEM POP RETURN TEXT BIT I enclose a cheque for ASC MWD REM STOP PLOT CRB ATN LEN FOR TIME UNPLOT CRF Please charge to my Access/ Barclay Card no SIN MCH NEXT WAIT COLOUR MEM COS POS ERROR SAVE CHAR MWD Name EXP COL INPUT LOAD SPRITE BASE FRA MOD PRINT ESCAPE SHAPE Address

thT RND . NOESC SPOT Export enquiries to: Powertran International, Hollom Down Farm, Lopcombe, Salisbury, Wilts SP5 1 BP 0264 781545 Telex 4 7 7 407 Ze,rrn,

10 ETI AUGUST 1983 NEWS:NEWS:NEWS:NEWS NEWS:NEWS:NEWS

TOBIE Award For LCD Team

The TOBIE Award for Research plications are, apparently, linked Achievementhasthisyear to water or marine life. For in- been won by the Physics Research stance, Water Boards findits team at the Royal Signals and lightness and ease of handling DIGE Research Establishment, very useful on certain of their Malvern. For some years now this very remote pumping and control team has been working on the locations, and one ofthe various uses of liquid crystals, in- strangest of applications to date cluding displays and addressing has been for use on an expedition methods,thistechnologyhas to the Amazon where it will be us- made possible the 128 x 256 ed for tests on a type of electric matrix liquid crystal cell fish. Scopex ask: is this the dawn developedin conjunction with of a new era in ATE (Aquatic Test Scopex Instruments Ltd., for use Equipment)? Scopex Instruments inthe Voyager digitalstorage Limited, Pixmore House, Pixmore oscilloscope. Avenue, Letchworth, Herts SG6 Many of the Voyager's ap- 1HZ. Tel (04626) 72771.

Fibre Optic The Bead's Links Needs ightdata have two new Anew range of ferrite beads L modules: on the leftis the manufactured by Stackpole Blue Box 16 -channel RS232 to are vailable exclusively to UKfibre optic interface that is, ap- manufacturersfromWalmore parently, simplicity itself to set up and use.Itis intended to be Electronics Ltd, 374 City Road, mounted on a wall, and can pro- SC817 SMART CABLE from correct pin to pin connection. 11-15BettertonStreet,Drury TheKPG-Hardware Housepro- Providing male to male and male Lane, London WC2H 9BS. Par- vide a link over up to 1 km of op- tic rightisa vides a simple, low cost method to female connection the Smart ticularly interesting is a lead tape cable. On the ofinterfacing 98% of RS232 Cable totally eliminates the need bead for use with automatic in- Eurocard mounted version that equipment. Ideal for equipment for break out boxes, debugging sertion equipment. requires a single 5 V supply. Lightdata,4hasRoad, salesmen and engineers the Smart cables and custom cables. KPG- Ferrite beads are a simple, in- Por- Cable's unique logic senses the Hardware House, 578-586 expensive, yet effective way to thcawl, Mid Glamorgan, Wales ' RS232 configuraiton at each end Chiswick High Road, London W4 obtain RF decoupling, shielding CF36 3AH. and automatically configures the 5RP. and parasitic suppression without sacrificing low frequency power or signal level. Unlike conven-Energy In The New Current Probe tional RF chokes, beads are com- pact, have no DC losses, and will Outback Model 711 Miniature Wide - Model 711 is available in a potted not couple to stray capacity and Anew $250,000 Solar Energy Theband Current Probe manufac- package with a 3ft co -ax cable introduce detuning or spurious Research Centreisto be tured by American Laser Systems, and standard BNC connector. oscillations. Installation of beads built in Western Australia. It will California,measures wideband The UKagent isDynamic is easy. Simply slip over the ap-be located next to the site ear- current .pulses without loading Technology Limited, Zonal propriateconductorforthe markedforaproposed new the circuit being tested. It induces House,AllianceRoad,Acton, desired noise suppression or high technology park, which is to be no appreciable capacitive nor in- London W3 OBA. frequency isoltion. established at the Western ductive effectson circuitry, Australian Institute of Technology therefore the signal under in Bentley. measurement does not change. the space-time continuum (that's The new centre will contain The 711 exhibits only 0.02 ohm Whoops! our story, and we're sticking totesting and monitoring equip- shunted by 4 µH insertion im- Stotron Ltd were just a little it). ment,computerfacilitiesfor pedance. The current is sensed by annoyed with us for saying Stotron would also like us toautomated data analysis, an in- placing the conductor through that their latest catalogue was point out that while they do con- formation and display area, and the centre of the probe, which dated 1982 (Digest Shorts, June). tinue to have offices in Hastings,office space for the staff of the willaccepta maximum lead In fact, they have now supplied readers should write to them at Solar Energy Research Institute of diameter of No. 20 AWG. For uswiththeirlatest,1983/4 72 Blackheath Road, Greenwich, Western Australia (SE RIWA). general use as a test probe with catalogue, to prove that the other London SE10 8DA, to obtain their Outside areas will be used to test oscilloscopes and test equipment, dropped through a worm -hole in copy of the catalogue. various types of solar equipment.

ETI AUGUST 1983 11 COMPUTER WAREHOUSE THE ff.` I I I: 0 0 A_ 1 , I i7:11 COMPOTER HARD DISK DRIVES All in one quality computer Fully refurbished Diablo/DRE Series 30 2.5 mb hard cabinet with integral switched disk drive for DEC RK05, NOVA, TEXAS etc DISTEL 0 mode PSU, Mains filtering, and twin fan cooling. Front load £550.00 - Top load £295.00 The UK's FIRST free of charge, 24 hr. public Originally made for the famous DEC PDPS computer PSU type ME3029 for 2 drives £125.00 access data base. Get information on 1000'ssystem costing thousands of pounds. Made to run 24 DRE 44A/4000A/B 10 mb 5+5 all configurations from hours per day the PSU is fully screened and will deliver a £995.00. Call sales office for details of stock items and order via your computer massive +5v DC at 17 amps, +15v DC at 1 amp and -15v and credit card. On line now, 300 baud. DC at 5 amps The complete unit is fully enclosed with CCITT tones, full duplex, fully interactive. removable top lid, filtering, trip switch, 'Power and 'Run' LEDs mounted on Ali front panel, rear cable entries, etc etc Units are in good but used condition - supplied for S AMP MAINS FILTERS DON'T MISSTHOSE EAROAINS7 240v operation complete with full circuit and tech. man. Cure those unnerving hang ups and data glitches FREE Give your system that professional finish for only caused by mains interference. size- Up to 5 CALL NOW, IrS £49.95 + Carr. Dim. 19" wide 16" deep 10.5" high. amp 240 v load As recommended by the ZX81 news- Useable area 18"w 10.5"h 11.5"d letter. Suppression Devices SD5A £5.95. Also available LESS PSU with internal dim. 19"w, 16"ci. 01868361133 wleerekanar412Th.10.5"h, £19.95". Carrie e & insurance £9.50. 0001Stil PA113 Keep your hot parts COOL and ABLE RECHARGEABLE BATTERIES with our range of BRAND NEW professional 8" FLOPPY CYCLON type 0001 sealed lead acid cooling fan& maintenance free 2v 2.5 ah. will deliver over ETRI 911XU0I Dim. 92 x 92 x 25 mm. DISK DRIVES Miniature 240 v equipment fan complete with 300 amps on short circuit!! Brand new at r guard £9.95. Unbelievable value the DRE 7100 8" floppy disk drivesonly £2.95 OOULD JB-3AR Dim. 3" x 3" x 2.5" compact utilise the finest technology to give you 100% bus very quiet running 240 v operation. NEW £9.95 compatibility with most drives available today. The only BUHLER 89.11.22.8-16 v DC micro difference being our PRICE and the superb manufactur- miniature reversible fan. Uses a brushiess ing qualityll The 7100 single sided and 7200 double sided II10 MONITO servo motor for extremely high airflow, drive accept hard or soft sectoring IBM or ANSI standard almost silent running and guaranteed 10,000 formats ng a massive 0.8 MB (7100) 1.6 MB (7200) of storage. Absolutely 12" CASED. Made by the British KGM Co. hr life. Measures only 62 x 82 x 22 mm. Designed for continuous use as a data SH , BASF, SIEMANS etc compatible. Supplied BRAND NEW with user Current cost £32.00. OUR PRICE ONLY display station, unit is totally housed in an £12.95 complete with data. manual and full 90 day warranty. Carriage and insurance £9.75. attractive brushed aluminium case with ON - MUFFIN -CENTAUR standard 4" x 4" x 1.25" 7100 Single sided £225.00 + Carr. 7200 Double sided £295 + Carr OFF, BRIGHTNESS and CONTRAST fan supplied tested EX EQUIPMENT 240 vat Optional accessories Full technical manual £20.00 alone. £10.50 with drive. Refundcontrols mounted to one side. Much £8.25 or 110 vat £4.95 or BRAND NEW 240v of difference on drive purchase. DC and AC power connector and cable kit £8.45. 50attention was given to construction and at £10.50. 1000's of other fans Ex Stock way IDC connector £5.50. 50 way ribbon cable £3.20 per metre. reliability of this unit with features such as, I for Detail& Post & Packing on all fans Et. internal transformer isolated regulated DC supply, all components mounted on two AM= fibre glass PCB boards- which hinge out for SUPER DEAL? NO - SUPER STEAL' r\--\ease of service, many internal controls for The FABULOUS 25CPS TEC Starwriter I/C1 ThIMMALS Imp -linearity etc The monitor accepts standard AtOM + CAR + VAT 75 ohm composite video signal via S0239 Daisy wheel printer at a fraction of its original,host.. Fullyftedged industrystandard A4133 data socket on rear panel Bandwidth of the unit terminal Many features including ASCII is estimated around 20 Mhz and will display 'ONLY Er -4 keyboard and printer for data I/O auto data most high def graphics and -132 x 24 lines. RANDO AI VAT=7 --"" detect circuitry. RS232 aerial interface.110Units are secondhand and may have screen Made to the very highest baud, 8 bit paper tape punch and reader for bums However where burns exist they are off line data preparation and ridiculously only apparent when monitor is switched off. 3470-26 TEtafuresritaer '-c-cheap and reliable data storage. Supplied in Although unguaranteed all monitors are heavy duty die cast "good condition and in working order tested prior to despatch. Dimensions chassis and DIABLO type Options Floor stand5/2.50 +VAT approx. 14" high x 14" wide by 11" deep. print mechanism giving KSR33 with 20ma loop interface.* t 2100 + Supplied complete with circuit 240 volt AC superb registration and Sound proof enclosureE2100 +VAT operation. KIM19.50 print quality. Micro- S 24" CASED. Again made by the KGM Co processor electronics with a similar spec as the 12" monitor. offer full DIABLO/OUME Originally used for large screen data command compatability SOFTY 2 display. Very compact unit in lightweight and full control via CPM Wordstar etc The amazing SOFTY2.Thecomplete"toolkit" alloy case dim 19" H x 17" D x 22" W. All Many other features include bi directional for the open heart software surgeon. Copies, silicon electronics and composite video printing, switchable 10 or 12 pitch, full width 381 mm paper handling with upto Displays, Emulates ROM, RAM and EPROMS input make an ideal unit for schools, clubs, 163 characters per line, friction feed rollers for single sheet or continuous paper, of the 2516, 2532 variety. Manyotherfeatures shops etc Supplied in a used but working internal buffer, standard RS232 serial interface with handshake. include keyboard, UHF modulator. Cassette condition. Supplied absolutly BRAND NEW with 90 day guarantee and FREE daisy wheel interfaceetc Functionsexceedcapebilitiesof ONLY ESS.00 PLUS E9.50 CARR. 4 MI. and dust cover. Order NOW or contact sales office for more information. Optional extras: RS232 data cable £10.00. Tech manual £7.50. Tractor feed units costing 7 times the price! Only 14" COLOUR superb chassis monitor made E109.00 PP C108Data sheet on request by a subsidiary of the HITACHI Co. Inputs £120.00. Sre dais wheel £3.00. Carrie e & Ins. UK Mainland) £1 0.00. are TTL RGB with separate sync and will plug direct into the BBC micro etc Exceptional bandwidth with good 80 cot DATA MODEMS definition. Brand new and guaranteed Join the communications revolution with our 8" WINCHESTER price Complete with full data & circuit 240 v AC range of EX TELECOM data modems Made to SlasSiel working. Dim. 14" x 13" x 13". most stringent spec and designed to operate 041111 1E199.00 PUN E9.50 CANN. for 24 hrs per day. Units are made to the Worldwide purchasing brings you two amazing Winchester CCITT tone spec With RS232 i/o levels via SCOOPS at prices that will likely NEVER be repeated.

a 25 way 'D' ski Units are sold in a tested , BASF 6172 8" 24 Mb. Complete unit consists of micro- and working condition with data Permission SEMICONDUCTOR may be required for connection to PO lines processor controlled logic on 3 PCBs for all read/write and servo control functions. Fast data transfer is by the BASF 'Disk `GRAB BAGS' MODEM 13A compact, async, same size as Mixed Semis amazing value contents telephone base Up to 300 baud, full duplex Bus' interface on a single 40 way multiplexed I/O bus. Units have include transistors, digital linear, Macs, over 2 wires, but call mode only £75.00 been carefully removed from believed working equipment, but at diodes, bridge recs., etc eta All devices MODEM 2B/C Fully fledged, up to 300 baud the staggering price of ONLY £99.00 are sold without guaranteed brand new full spec. with manu- async, ANSWER & CALL modes, auto answer, guarantee. Supplied complete with 200 page + tech. Manual. facturer's markings, fully guaranteed, auto switching, ideal networks etc Just 2 wire 50+52.95 100+1.5.1* connection to line. £85.00 Dim 45 x 22 x 11 cm. DC requirements +-5v, -1--12v, +24v. TTL 74 Series A gigantic purchase of an MODEM 20-1 Compact unit for use with Carriage and ins. £10.00 "across the board' range of 74 TTL series PRESTEL or full duplex 2 wire link 75 baud S100 Bus 19 Mb. Subsystem. A cancelled order and change I.C.'s enables us to offer 100+ mixed transmit -1200 baud receive Auto answer. "mostly TFL" grab bags at a price which two £130.00 of policy by a major British disk drive manufacturer enables us or three chips in the bag would nnormally MODEM 20-2 same as 20-1 but 75 baud to offer you 'last year's model' at a plug in and ready to 90 cost to buy. Fully guaranteed all IQ's full receive 1200 baud transmit £130.00 SUPER LOW PRICE. Our own custom controller pugs direct into spec 100+56.90 200+512.30 300+£19.50 MODEM 20-3 Made for data rates up to 1200 the S100 bus and will control 2 disk drives, offering a total baud in full duplex mode over 4 wire circuit or storage of OVER 36 Mbs! and at data transfer rates in excess of half duplex mode over 2 wires. £130.00 rriage 13A £4.50.28/C & 20 £9.50. 7 Mb/sec seeing is believing!! Supplied complete with user CALLING DEC DATA PUMP MODEM compact unit upto configurable BIOS etc. Save a fortune, Limited quantity only. 1200 baud full duplex over 4 wires or half 3100 19 Mb. Disk driveE499.00 PSU unit £165.00 USES duplex over 2 wires. BELL specification with CD1100 controller & BIOS £345.00PSU extension cable E9.95 Brand new and boxed data i/o via RS232 25 way D socket, remote test etc 240 v operation. Supplied complete Full tech Manual 00.00 RSX11M 3.2 Documentation kits, fill with data £65.00 can. £4.50. 3 feet of your bookshelfl Under half Special SUBSYSTEM prices. 1 x 3100 disk + PSU + Controller E799.00 price only £120.00 carr. £6.50 0 vat or 2 x 3100 disks + 2 PSU + Controller E129100 For more information or details of other types All prices + VAT and carriage. 90 day guarantee. Data on request. on manuals. of ex stock modems contact sales office. We are always keen to buy all types .11_VAT f used or sur lus DEC equipmen All pricesquotedarefor U.K Mainland, paid cashwith order in Pounds Stirling PLUSVAT.Minimumorderval :3 MinlmumCredlt Cardorder5/0.00. Minimum BONA FIDE account orderstrom Governmentdepts, Schools, Universitiesandestablishedcompanies £20.00 Where post and packing not indicated please ADD180p+ VAT Warehouse open Mon -Fri 9.30- 5.30. Sat. 10.15 - 5.30 We reserve the right to change prices andspecifications without notice. Trade, Bulk and Export enquiries welcome. 1-1-71-1.1-1MP:,_ 64-66 Melfort Road, Thornton Heath,Near Croydon, Surrey -1--/-1-1- IIN I-11 111- 01-689 7702 -01-689 6800 Telex 27924 -kJ 12 ETI AUGUST 1983 NEWS:NEWS:NEWS:NEWS:NEWS:NEWS:NEWS

The Phone

That Thinks 31{ It's A Clock irg The new Clock Radio Phone from Fidelity Radio, the CRP ittitiONSK 100, is a compactunitin- coporating the three facilities of radio, alarm clock and telephone. Operation is precisely the same as a conventional clock radio but with an automatic cut off when the telephone receiver islifted. British Telcom approval is already applied for and the CRP 100 can be installed by connection to the mains and a standardBritish Telecom socket. The Clock Radio Phone is expected to retailat around £69, and should be in the shops by September. Also from Fidelity is a new col- our television chassis design, the ZX 3000. The chassis is smaller, more advancedwithreduced component volume and covers eight programme channels. Ad- vantages across the range include greater reliability, less weight and an even more economical price for high quality vision and sound reproduction. You'll find the new chassis in some new models, the CTV 22T and CTV 20T Teletext models, the CTV 22R remote control model meet the customer's specifica- and a new 14inchcolour Speedy Prototypes tion, however tight. Computing monitor. The existing CTV 20R Techniques (Mfg) Ltd, Brookers and CTV 14S portable will con- Computing Techniques (Mfg) manufacturers. Road, Billingshurst, West Sussex tinue in the range but with the Limited has introduced a fast The service should prove of RH14 9RZ. new chassis. and economic service on opera- great interestto smalland tionalamplifiers designed and mediumquantityusers, who builttospecialrequirements. oftenexperiencedifficultyin Please.. Micros Go Now, all but the most exacting eqsily, or economically, meeting At the time of writing, ETI is orders can be met in two weeks or specifications when selecting sti!lwithout a replacement less. Many orders can be turned standard linear integrated circuits forPeterGreen,our former Down The round in as little as seven days, from the major suppliers. Com- deputy editor turned Computing and this British company is offer- putingTechniquessuppliesa Toady. So please, keep your en- Drain ing prices at up to 25% lower complete, packaged operational quiries of us to a minimum, and than those quoted by other major amplifier which it guarantees will follow the guidelines on page 70. ntel Corp has introduced its I "Data Pipeline" hardware and software designed to link main- frame computer data bases with A Little Pull personal computers. The Data Pipelineisbuilt around Intel's Helps Data -BaseInformationSystem, Miniature solenoids for use iDIS 86/735, a microcomputer - where space is at a premium based "traffic -manager" that in- have been introduced by terprets,stores and distributes Magnetic Components to aug- mainframe data to and from ter- mentitsestablishedrecording minals and personal computers. head capability. Manufactured to The Data Pipeline uses an meet manufacturers' specific re- enhanced version of Intel's quirements, theunitsareex- System 2000 Data -Base Manage- pected to have particular applica- ment System (DBMS). System tion to electronic security locks, 2000 currently handlesdata access controls, low power storage and retrieval in hundreds system controllers, printer oflargemainframe computer mechanisms, electronic camera installations. shutters, etc. New Data Pipeline extensions Typicalis one producing a to System 2000 provide a rela- latch pull force of 150 gms when tional data -base capability, 1.9 volts D.C. is applied to the 75 graphics and a fourth -generation ohms coil.Inaddition to the softwarearchitecture, System solenoid component, MCL pro- 2000 On -Line Operation (SOLO). vides methods of controlling the Intel also has broadened its unlatching force so as to give a 700 family of Data -Base Informa- higherlevelofreleasetime tion Systems withtheiDIS repeatability; this is achieved by a 86/730, an iDIS, version aimed at specially developed keeper original equipment manufac- and/or the use of 'kick-off' elec- turersandlarge -volumeend tronic circuitry. Magnetic Com- users. Intel Corporation S.A., Rue ponents Limited, Bridge Wharf du Moulin a Papier, 51, Boite 1, Industrial Estate, Chertsey, Sur- B-1160 Brussels, Belgium. rey KT16 8LJ.

ETI AUGUST 1983 13 electrorize AUTO -ELECTRONIC PRODUCTS KITS OR READY BUILT TOTAL ENERGY DISCHARGE PROTECT ELECTRONIC IGNITION YOUR CAR WITH AN ELECTRON= ELECTRONIC ALARM

IS YOUR CAR AS GOOD AS IT COULD BE ? * Isit EASY TO START in the cold and the damp? Total Energy Discharge will give the most powerful spark and maintain fulutput even with a near flat battery. * Isit ECONOMICAL or does it "go off" ignition performance deteriorate much more output and ma * Has it PEAK PEMF a ow revs. where th ischarge gives 2000 COMBINATIONS provided by an electronic key - a en with miniature jack plug containing components which must match each individual alarm system. (Not limited to a few hundred spark of keys or a four bit code). st an cetc. 60 SECOND ALARM PERIOD flashes headlights and sounds horn, then resets ready to operate again if needed. * Do the P n ging to bring the engine y DisCharge eliminates contact arcing a ving =heavy electrical load. The timing 10 SECOND ENTRY DELAY allows owner to dis-arm the stays "s e contact condition doesn't affect the system, by inserting the key plug into a dashboard mounted

performan . Larger plug gaps can be used, even wet or socket,before the alarm sounds. (No holesinexternal badly fouled plugs can be fired with this system. bodywork, fiddly code systems or hidden switches). Re - * TOTAL ENERGY DISCHARGE most closing the door will not cancel the alarm, before or after it powerful on the market - 31/2 times the power of inductive systems - sounds, the key plug must be used. 3 Y2 times the energy and 3 times the duration of ordinary capacitive systems. These are the facts: INSTANT ALARM OPERATION triggered by accessories or Performance at only 6 volts (max. supply 16 volts) bonnet/boot opening. SPARK POWER 140W, SPARK ENERGY - 36mJ SPARK DURATION 500pS, STORED ENERGY - 135mJ 30 SECOND DELAY when system is armed allows owner to LOADED OUTPUT VOLTAGE lock doors etc. 50pF load 3810/ 50pF + 500k - 26kV We challenge any manufacturer to publish better performance DISABLES IGNITION SYSTEM when alarm is armed. figures. Before you buy any other make, ask for the facts,its probably only an inductive system. But if an inductive system is IN KIT FORM it provides a high level of protection at a really what you really want, we'll still give you a good deal. * All ELECTRON IZE electronic ignitions feature: low cost. The kitincludes everything needed, the case, EASY FITTING, STANDARD/ELECTRONIC CHANGEOVER fibreglass PCB, CMOS IC's, random selection resistors to set SWITCH, STATIC TIMINGLIGHTandDESIGNED IN the combination, in fact everything down to the last nut and RELIABILITY (14 years experience and a 3 year guarantee). washer plus easy to follow instructions. * IN KIT FORM it provides a top performance system at less than half FITS ALL 12 VOLT NEGATIVE EARTH VEHICLES. the price of comparable ready built units.The kit includes: pre -drilled fibreglass PCB, pre -wound and varnished ferrite transformer, high SUPPLIED COMPLETE WITH ALL NECESSARY LEADS AND CONNECTORS PLUS TWO KEY PLUGS quality 2p F discharge capacitor, case, easy to follow instructions, solder and everything needed to build and fit to your car. All you need is a soldering iron and a few basic tools. Don't Wait Until Its too Late - Most NEW CARS already have electronic ignition. Update YOUR CAR Fit one NOW!

fill in the coupon and send to: ELECTRONIZE DESIGN Dept D. Magnus Rd Wilnecote Tamworth B77 5BY tel 0827 281000 mum mum mos as NI WM NI1.1NS ENI= MIIN IN 111111111111MIMall Ell MI1M NI 11111 IM1Ell MN 11 TOTAL ENERGY DISCHARGE (6 or 12 volt negative earth) CAR ALARM El Assembled readyto fit £28/0 £19.95 Assembled ready to fit £3795

I D.I.Y. parts kit £1.54) £14.95 I D.I.Y. parts kit £24.95 TWIN OUTPUT for cars and motor cycles with dual ignition I enclose cheque/postal order OR debit my Access/Visa card Twin, Assembledready to fit £$6.45 £29.95 115A LL1111_11111111111 n Twin, D.I.Y. parts kit MIS £22.95 Name INDUCTIVE DISCHARGE (12 volt only) Address ri Assembled ready to fit £15195 £12.75

Prices Include VAT. Code NEWS NEWS.NEWS:NEWS:NEWS:NEWS:NEVVS

What Is It? We know what it is - but do you? We get allsorts of obscure objectspassing under our noses here at ETI, but this particular one seems to mark a new all-time height in enigma. Actually, it's use is pretty bor- ing, so we're not giving any prizes for the correct answer. However, Motorola's European Literature More Motorola Manuals Centre (at Milton Keynes) for the themostingeniousincorrect leaflet, describing each publica- answerwillgetsomeprize, Motorola havebeen busy Transistors; 8038 - Linear/Swit- though what itis, we haven't tion and detailing prices. scriblingaway, andthe chmode Voltage. MotorolaSemiconductors, 88 decided. It could be a guided tour following new books bring the Theseareavailablefrom tanners Drive, Blakelands, Milton of the ETI office, or it may even total number of Motorla tehcnical Motorola Distributors, or write to Keynes. be one of these things - you'll publications up to 22: B012A -8 have to wait and see. bit Microprocessor Data Manual; B012B - 16 bit Microprocessor One of the consequences of Data Manual; 13001 - A/D and Shorts the general election being called Filters For CD D/A Conversion Manual; B0015 at fairly short notice was the fall RIFA have introduced a new - Switchmode and TMOS Power of a bill that would have made it series of hybrid active filters, United Components Ltd, Unit illegaltosell "any machine which have been designed for 5, Wye Estate, London Road, capable of reproducing a sound anti-aliasing applications in High Wycombe, Bucks HP11 1LH recording ... where the naute of equipment such as digital audio Accurate now carry stocks of Clare Reed the machineissuch that the systems. Constructed inRIFA's and mercury wetted relays, as primary orsubstantialuse to thick film process, the PBA 3167 Robot well as many other GI and related which it will be likely to be put is and PBA 3179 hybrid active filters Zehntel's Series 600 Robotic companies' products. likely to result in the unauthoris- feature an extremely flat response Board Handling System, the Any manufacturer wishing to ed making of any record embody- over their operational passband. first fully operational robot aid exhibit at the fourth Middle East ing the recording ... ". Sounds Included in their circuitryis a for automatic testing equipment, Electricity and Electronics Exhibi- like a cassette deck they were group -delay equalising network, is described in a 4 page brochure. tion in Kuwait in January 1984 talking about, doesn't it? which effects a constant group - The RBHS is easily programmed should contact the British Elec- Thorn EMI have just released a delay response within + 10/4s up and has a unique 6 axis motion. trical and Allied Manufacturers' leaflet describing a new range of to 19KHz in the case of the PBA Positioning accuracy is 0.022", Association (BEAMA) at 8 rubidium caesium photocathode 3167, and up to 13.5 KHz for the believed to be the best available. Leicester Street, London WC2H photomultipliertubes.Contact PBA 3179. As well as loading and 7BN. the Sales Department, Thorn EMI Cut off frequencies are unloadingboardsatthetest Peripheral Hardware Ltd, Unit ElectronTubesLimited,Bury specified as 20KHz (3167) and head, the RBHS can also be used 13, Monkspath Industrial park, Street,Ruislip, Middlesex HA4 15KHz (3179). Accordingly, the for light mechanical tasks con- Highlands Road, Shirley, West 7TA. filters are ideally suited for ap- nectedwithtesting,suchas Midlands 890 4NY have been ap- Belling Lee have published a plications in digital audio systems operating switches etc. It will also pointed as an authorised dealer comprehensive 64 page catalogue having sampling frequencies from handle simple assembly tasks if for Epson printers and personal of their range of RFI filters for up 48 to 50KHz, or 32KHz. RIFA AB, required.ZehntelLimited,62 computers. to 800 amps. Belling Lee, 540 Market Chambers, Shelton Tanners Drive, Blakelands, Apples have fallen. A newGreat Cambridge road, Enfield, Square, Coventry. Milton Keynes MK14 5BP. 256K Apple III will now cost a EN1 3QU. mere £2,395 (it was £2,869); the Cotswold Electronics, Unit T1, 128K AppleIIIisnolonger Kingsville road, Kingsditch Noisy Fault Locator available. Apple Computer (UK) Trading Estate Cheltenham GL51 Anew British manufactureredponents or cutting tracks. Ltd, Eastman Way, Hemel Hemp- 9NX have issued a leaflet describ- stead, Herts HP2 7QH. ingtheir and designed portable The instrument has four "budget range"of AudioNisual faults locator is now ranges to allow resistance AKG are setting up a studio toroidal mains transformers. available from Antron Electronics measurement up to 20k and D.C. sound award, forprofessional Tasbian, the automated elec- Ltd, Hamilton House, 39 Kingsvoltages between ±20V to be and non-professional sound tronic assembly plant near Road, Haselmere, Surrey GU27 made, so giving a complete range engineers.Detailsfrom AKG Plymouth, have alsoissueda 2QA. Codenamed Toneohm 700, of diagnostic capability in one in- Acoustics Ltd, 191 The Vale, Lon- leaflet, describing their design, the instrument is used to locate strument. Kelvin needle probes don W3 7QS. manufacturing and test facilities. short and partial short circuits are used for fault finding and are InstemComputerSystems Tasbian Ltd, 2/3 Burrington Way, caused by solder bridges, poor et- protected against accidental con- Limited, formerlyknown as Plymouth, Devon PL5 3LS. ching, partial device failure, i.e. nection up to ± 30V. Kratos, has launched a new soft- You'll no doubt be pleased to substrate shorts, leaking The instrument can also ware programme for the Hewlett hear that the 20 companies in- capacitors etc., by tone or meter source a test voltage to stimulate Packard HP -86 microcomputer to volvedinthe development of readout without removing corn - circuit under test, with a max- performindustrialmonitoring magnetic disc stills cameras have imum output voltage of 0.55V and control functions using In - reached agreement of standar- and maximum output current stem'srangeofLink -Onin- disation of the disc. This should 150mA. put/output stations. Instem Com- prevent the usual problem of a Twin Stripper puter Systems Limited, Walton multiplicity of standards confus- AB Engineering Company has Industrial Estate, Ston, Stafford- ing the consumer, such as hap- /A developedaunique new shire, ST15 OLT. pened in video. cable stripper for the fast and safe removal of outer sheathing from twisted pair coaxical cables. Also suitable for other cables of ir- regular cross section, the new Coax -3 incorporates aspring loaded cutting head which when revolved accurately follows con- tours to produce a precise cir- cumferentialcutto a pre- determined depth. The operator then simply twists the cutting blade through 90 degrees and the outer sheating is separated along the axis of the cable for ease of removal. AB Engineering Co., Timber Lane, Woburn, Milton Keynes MK17 9PL. ETI AUGUST 1983 15 01-4521500 TFAIINomATIc LTD 01-450 6597 BBC Micro Computer System FLOPPY DISC INTERFACE OFFICIAL Please phone for availability Incl. 1.2 operating system DEALER £95 + £20 installation BBC Model B £399 including VAT plus £8 carr. BBC FLOPPY DISC DRIVES Model A to Model B Single drive 51/4" 100K £230 + £6 carr. Upgrade kit £50 Dual drive 51/4" 800K £699 + £8 carr. Fitting charge £15 BBC COMPATIBLE DRIVES Individual upgrades These drives are self powered and also available supplied in BBC matching colour cases. SINGLE 100K £180; 200K £250; 400K £330 WORD PROCESSOR 'VIEW' WORDWISE DUAL 200K £350; 400K £475; 16K ROM £52 8K ROM £39 800K £590 TORCH Z80 Drive Cables: Single £8 Dual £12 TELETEXT ADAPTOR DISC PACK £780 Disc Manual & Formatting Diskette £17.50 £195.00 Phone or send for our BBC leaflet BUSINESS, EDUCATION & FUN SOFTWARE IN STOCK CASSETTE RECORDER MONITORS BBC BOOKS BBC Compatible Cassette Recorder Basic on BBC £5.95 with Counter and Remote Control MICROVITEC 1431 14" Colour Monitor 1249 + £8 cart. 30 Hour Basic £5.95 £26.50 + £1.50 carr. MICROVITEC 2031 20" Colour Monitor £319 + £8 carr.Programming the BBC Micro £6.50 SANYO Data Recorder Model DR101 KAGA 12" RGB Monitor £255 + £8 carr.BBC Micro An Expert Guide £6.95 £39.50 + £1.50 carr. Assy. Lang. Prog for BBC £8.95 Cassette Leads £3.50 Lead for KAGA/SANYO RGB £10 SANYO 12" Hi Res Green Monitor ... £99 + £6 carr.6502 Machine Codes for Beginners Computer Grade Cassette £6.95 (No VAT) £0.50p each £4.50 for 1 0 + £1 carr. SANYO Hi Res RGB Monitor £445 + £8 carr. NEC PC 8023 BE -C PRINTERS EPSON RX80 and FX80 Features include: RX80 1 00CPS 8000L 80 cols 100CPS, SEIKOSHA GP 100A Bi-Directional, Logic seeking, Tractor Feed £298 Proportional Spacing, 80 Cols 30 CPS FX80 1 60CPS 8000L Forward & Reverse Line Full ASCII e GRAPHICS F&T Feed £389 Feed, Hi -Res and Block 10" Wide paper MX100 F/T3 £425 Graphics, International and Greek characters, Now only £180+ £6 carr. (Carr./printer £8) Auto -Underline, Full specification Friction & Tractor, GP250A £235 plus £8 carr. on request 2K Buffer, Cartridge Ribbon. Parallel Printer lead for BBC/Atom to most printers £13.50 Variety of interfaces, ribbons in stock £345 + £8 carr. 2,000 fan fold sheets 91" x 11" £13.50 + £3 p & p ID CONNECTORS CONNECTORSYSTEMS RIBBON CABLE 'RUGBY ATOMIC CLOCK Header Recep-Edge JUMP LEADS AMPHENOL CONNECTORS Grey/meter This Z80 micro controlled clock/calender Plug tacle Conn 4in Ribbon Cable with headers 36 way plug Centronics Parallel receives coded time data from NPL Rugby. 10 way 90 85 120p 14 pin16 pin 24 pin 40 pin Solder £5.25 1DC £4.95 The clock never needs to be reset. The 20 way 145 125 195plend 145p 165p 240p 390p 10 way 40p 36 way socket Centronics Parallel16 way 60p facilities include 8 independent alarms and for 26 way175 150240 2 ends 21°P 230P 345P 540P Solder £5.50IDC £5.20 34 way 200 24in Ribbon Cable with sockets 20 way 85p each alarm there is a choice of melody or 160320 26 way 120p alternatively these can be used for electrical 40 way220 190 340 20 pin 28 pin 34 24 way plug IEEE ,and160p 200p 2809pi 300ppp Solder £5.00 ADC £4.75 34 way 160p switching. A separate timer allows recording 50 way 235 200390 2 ends 290p 370p 480p 525p 40 way 180p of up to 240 lap times without interrupting 24in Ribbon Cable with D. Conn24 way socket IEEE 50 way 200p the count. Expansion facilities provided. D -CONNECTORS 25 way Male 500p Female 550p Solder £5.00 64 way 280p See July/August ETI for details. Complete Kit No of Ways £145+ £2.00 p&p 9 15 25 37 RS 232 Jumpers Test Clips Male (25 way D) 14 pin 275p EDGE Solder 80p 105p 160p 250p 24" Single end Male £5 16 pin £3 CONNECTORS Angled 150p 210p 250p 365p24" Single end Female £5.25 40 pin £6 Female 0.1" 0.156" MICROTIMER 24" Female -Female £10 2x18 way- 140p 6502 Based Programmeable clock timer with Solder24"105p 160p 200 p335p Male -Male £9.50 EURO 2x22 way 190p 240p Angled 165p 215p 290p 440p * 224 switching times/week cycle 24" Female -Male £9.50 2x23 way 175p - Hoods 90p 85p 90p100p CONNECTORS 2x25 way 225p 220p * 24 hour 7 day timer - IOC 25 way plug 385p DIN 41617 Plug Skt 2x28 way 190p - * 4 independent switch outputs directly interfacing to Socket 450p DIL HEADERS 21 way 160p 165p 1x43 way 260p - thyristor/triacs . Solder IDC 31 way 170p 170p DIL DIN 41612 2x43 way 395p * 6 digit 7 seg. displays to indicate real time, ON/OFF and ResetTEXTOOL ZIF SWITCHES typo 11/1. 1x77 way 600p times Sockets 4 way 70p 14 pin Opploop 2x32 way St. Pin 220p 275p5100 Conn 600p 24 pin £5.75 16 pin 60plin- . 2x32 way Ang. Pin 275p 320p * Output to drive day of week switch and status LEDS. 6 way 85p 3x32 way St. Pin 28 pin £8.00 8 way 90p 24 pin 1009 150p 30p Full details on request. Price for kit f57.00 3x32 way Ang. Pin 375260pp350p 40 pin £9.75 10 way 140p 40 pin 200p 225p SPECIAL OFFER DISC DRIVES FOR THE FORTH COMPUTER SOFTY II INTELLIGENT PROGRAMMER 2532 350p 51/4" Teac F055 Slim Line Mechanisms The complete micro processor development system for Engineers and Hobbyists. You can 2732 FD55A 40 track SDD 250kbytes unformatted develop programs, debug, verify and commit to EPROMS or use in host computer by using 2764-25 450p bare: £1 35 Cased: £155 softy as a romulator. Pmkerful editing facilities permit bytes, blocks of bytes changed, deleted 27128-25 625 or inserted and memory contents can be observed on ordinary TV. Accepts most 5v Eproms, 4116-2 80p 2 x FD55A 40 track SSDD 500kbytes unformatted Softy II complete with PSU. TV Lead and Romulator Wad E169 4164-2 .45 cased + psu £350 6116P 3500pp FD55E 80 track SSDD 500kbytes unformatted bare: £1 80 Cased: £205 BOOKS (No VAT pap f1) 2 x FD55E 80 track SSDD 1 Mbyte unformatted cased + psu £475 E.T. I. CRT Controller H/Book £8.50 UV ERASERS Programming the 180 £11.50 51/4" Mitsubishi M4853 Slim Line mechanism UVIB up to6Eproms £47.50 PROJECTS 80 track DSDD 1 Mbyte unformatted ZOO Microcomp. handbook LOA bare: £225 Cased: £245 UVIT with Timer £00.00 Semiconductors inc. Programming the 6502 £10.25 2 x M485 2 Mbytes Cased + psu £590 UV140upto14Eproms £61.50 I.C., Transistors, 6502 Assy. Lang. £12.10 UV141 with Timer £/8.00 6502 Applications NIA Single drive table ES Dual Drive cable Et 2 Displays, Connecors 6502 Software Design 81.05 Other parts for FORTH COMPUTER available send SAE for details. (Carr f2/eraser) and Sockets for most All erasers are fitted with 6502 Games £10.52 projects are stocked Large selection of databooks, inter- mains switches and safety by us. facing books, books on BBC, etc in PLEASE SEND SAE FOR PRICE LIST interlocks stock. As for our list.

16 ETI AUGUST 1983 741% 805 7415251 39p 0244 1605 74199 41 7415283 me 40248 1110p LINEAR ICs. COMPUTER COMPONENTS 'MR7400 11P 74221 665 7415266 150p 4018 45p 507581 14505 LAA377 1759 8288 E11 7401 lip 74251 465 7415257 309 4019 25p NE5534P1105 75491/2 614151.114F 3750 Aocoses MlOp LM380 715p NE5534AP 1205 8755 £18 7402 lip 74259 1005 7415258 3654020 469 .1802CE 4805 NN -35 .111:8126 1209 %Mt UHF 4600 AN103 38105 1.1.1331011805 9902 E3 8128 12011 NEC 121/ 74265 41.5 7415259 Sp 0021 40p PLL024 500p 2650A El2 7404 125 AY1-6050lip1M382 1209 804136 TMS4500 £14 8196/96 905 74273 1205 7415260 200 ,4022 455 80p 6502 3505 7105 T55 74276 9013 AY3-1270 0265 LM386 90p RC4151 2005 2801310 250p 8197/98 90p 32.7881/10 10,:p 74LS201 138p I 4023 135 6502A 500p 7406 1115 AY3-1350 2605 194387 1205 280AP10 2805 811$95/96 sop 74278 1009 7415266 20p 32p 55658 226p 6930 2265 10014K: 2509 7407 Ilp 144389 969 250p 811597/913 80p 74279 40 p 7415273 1109 4025 13p AY3430104499 65419130 Eli 2193p nem 200HID 210r 7408 149 1M391 11505 sew 21105 74283 SOP 7445275 2265 4026 80p AY18912 1125p SFF96348005 8805 280ACK 881.5120 250p 01981011744 7409 LM3921 805 6809 CR16645 9005 14P 74284 1410p 7415279 305 4027 205 AY5-3803000p S1490 3605 68809 E12293513581 7005 9602 2205 1.0 290p 7410 115 74285 AY4007D E0 LM393 100p CRT5027 818 9E37AP 14105 1.008 too 741-$280 1005 4028 10p SN76131 1215p 6809E E12 Z9OAOMA E10 2759 1115 74290 CA3019 84 LAS394CH 300p 01115037 Ell 1.8432 76P 741.52133 405 4029 465 5176477 46058035 3505 280510/1/2 E9 25425E8 3605 210p 7412 14p 74293 CA3028 120p LA4709 3843 EF9365 6 116 14426E 8 350p OOP 7415290 165 4030 15p 517E4E8 450p 3005 200 225p 74137411 185 74298 lop LM710 SOp MC6845 11605 1014 7415293 40p 4031 100p CA3046 $187488 4005 214422 76 8 8005 2.45760 210p 7414 111p 74351 1505 2205 LM711 713p 8086 £4 MC6847 %Op 24428E 8 SOOp 741-5295 90p C3048 5176495400p8090A 2101-4A4005 2.5 210p 7416 1183 74385 CAA 3059 2865 1M725 300p SFF96364 48 my 7415297900p 4033 125p 5176660 120583854 2102.31 1205 2.662 250p 7117 Bp 74366 CA3060 sopLM733 80p 3 El505l TMS9918 EGO 3.276 7415298 50p 4035 45p SP0258ALZ 81 1158080 21078 soop TMS9927 7420 BP 74367 330p0p CA -10133E 72p1M741 18p 018 3.5795 106p II1p 7415299imp 4036 2751, 20 150514459980 CIO 2111A 3005 7421 74388 309 CA3096 410,L11747 70p 71109928 120 3686 300p 20p 7415321 imp 4037 110p TA7130 1505 TM59995 E12 2112.A 3005 F01771 120 7422 74376 100p CA30B9E2000 1_14748 35p TMS9929 E20 4.00 150p 20p 741_5323 imp 4038 110p TA7204 200p TMS1601£12 2114-2L 104 FD1791 at 7423 70390 75p CA3090 £4 1941014 150p 4.194 200p 7425 105 7415324}sap4039 290P TA7205 905ze E24 2147 450p F01793 E23 74393 909 053130E 9051141801 300p FD17% E28 143 110p 7426 111p -7415348 10p 4040 40p TA7222 15Z90 2905 4027.3 304 CA31301 1105 LM 1830 2509 mannom 4.606 250p 7427 lep 741$352 4041 40P 157310 150505 2805 324 4116-15 124 F01797 CA3140T 9051111871 460p 4.915 250p 11115 TBA800 2800 812 4116-20 8105 8271 E36 7428 7415353 010pp 4°42 4°P 450p AD558CJ 7750 28gp 4043 053140E 505 11141872 4118-3 4605 14/131611 E15 5.0 1750 7430 11p 741500 7415356 405 7005715810 1008055 8088 E18 AD561J E211 119 CA3160E1005 LA41886 wnrui 5501, 6.0 7432 11115 741$01 11p 7415363 1405 4°44 4°P LM1889 360p7134820 8058748 E111 41642 4000 AM25510 350p imp 4045 11:64,CA31615 150p 1615920 41 64-1 5 450p 902793 942 6.144 15050pp 7433 225 74/502 11p 74/5364 LM2917 200p 2099 AM25152521E2 4046 SOP CA3162E 4505 70 50p 7437 22p 7415365 zip 785950 22513 . DF ,GE 4416-20 500p A14261531125p FD27 97642 741603 125 300pLM3302 755 7.168 175p 7438 Zap 7415356 27p4047 455CA31896 TC9109 9005 4532-20 3005 741504 Bp 053240E 1105 LM3900 50p 324 .47426532 1250 CHARAC.,ER 8.00 17643 7439 250 74LS% 12p 7416367 np 4048 501) 869TCA210 4 4 1 6-2 0 £5 GFNERAICIAs 4049 CA3280G LM3909 3245 .0305 07002 4805 8.86 750 7440 isp 741$06 7415388 2411 125pTC4220 350p 41316APZ-3 2705 120 4050 24pD7002C 420p1M3911 65211 2869 DAC90 128 moo 1750 7441 15p 741507 12p 1M3914 200pICA270 350p 5101 3005 RO-325130C750p 95p 4051 45p 8522 3105 5514 0048131 3755 10.5 250p 7442.A 205 741500 12p 0500800 £2 1M3915 200pTCA940 1755 7505 AO -3:25131C 7005 70p 74174153735374 15p 4052 110p 66224 8599 DP8304 4805 10.7 150p 7443 74/509 12p DG308 300pLM3916 TC49135 120p 6116193 71305 S174526241 BO 7444 70p 7415375 460 4053 50p nap 6532 560p DS3691 300P 12.00 50p 741510 12p 1141366 186p L M13600 1119 1041004A E3 61 1 6P-3375pDS8830 140pMC66760750p 14.318 7445 Sep 7415377 1105 4054 905 6551 660p 175p 74/511 13p HA131313 270p M515131 23_ 10A1033 320p 6514-45 5505 1405 74485 90p 7415378 609 4055 905 6821 1035 D58831 DM86564 E12 14.756 250p 741512 120 1C17106 700p9451516/ 500p 1051010 2005 6310 12013 DS8832 250p 74475 3OP 7415363 46p 4056 805 68821 220p ..F5ROARD 1500 200p 741513 1017611 95p M83712 2005 1051022 500p 7489 2111p DS8833 225p 7448 46p 15p741.5393 45p4059 45011 6829 £12.50 F SWIM S 16.00 200p 741_514 ICL 7650 40054483730 10851DA1020 1205 746189 225p 1505 17.7 7450 Bp 25p7415395 90p '4060 56P 6840 3755 058836 200p 1C17660 2509MC1310P1505 1051170300, 746201 3505 1368838 2255 AY5-2376 7005 18.00 200p lip 74/515 120 741.5389 1811p 4063 569 68840 8005 1017660 2005 MC1413 75p 11352003 325p 745289 1755IF13201 4605 740322 4205.18.432 150p .77453 11141451 741520 1A,7416445 1005 4086 21P 6850 1105 300p 19.968 160p 7454 15p 741$21 12p 7415487 Kip4067 2255ICL8038 MC1445 250P TLIA2002V E3 59%0 2205 93415 800p MC1488 55p 7409235 5005 7460 Bp 741522. 123, 7415480 2085 40% 14pM7 L82 1 688 £2 2MC1458 365 7042006 350p6852 2505 93425 6005 MC1489 559 20.00 200p MC1493 100p RAU0 RATE 7470 30p 74LS26 1.2p 7415540 4069 1451CM7217 7505 ymazgzi 320p6954 7005 MC3418 %Op 26,1390 160p SOP 350p 100p ROMs PROM, GENERATORS 729 741. 3p 7415541 lop4070 145ICM7555 805 MC1495L 11064 68854 8005 MC3446 300p 27.145 21:00 ICL7611 905MC1496 705 moms,ap 850p 1750 74737472 250 741528 114p-527 4071 145 6875 5705 745188 325pMC3480 MC14411 6755 38.6667 7415610 E19 120p 7474 Alp 741530 179 wp 4072 145LC7120 3005 MC3340P 71072/82 8154 950p 745287 3505 MC3486 5005 COM8116 700548.0 175p 7415824 50p 7475 2AP 741532 13p 4073 145107130 325pMC3401 TL074 1.005 18155 35013 745288 225p MC3487 3005 47020 7505 55.5 741.533 7416828 1605 LC7137 2705 MC3403 75p 116 70806 26P47 14p 4075 140 TL083 705 3505 745 387 325p MC4024 3259 741537 7416828 1105 MFIOCN 250p MCA044 3255 145.80 2939 7 411p 1457416829 4076 485 LF347 1505 11.084 905 8205 2255 745471 654 UARTs 1209 74/6313 165 lip MK50240 03 6212 1105 MC14411 6755 15.068 7481 741.6840 100p 4077 165 LF351 485 11094 2005 745473 664 Op 741640 12p MK50398 E7 MC14412 7505 124 00 E2 7482 7415841 1005 4078 165 LF353 96p 11170 50p 8216 1005 745474 660p AY.31015P 7483A 314, 741542 4081 149 8224 110p 75107 905 up7415643 1005 LF356P 95pML920 800p11.430C 70p 3005 7484 859 741547 4082 155 8226 2505 EPROMs 75110/12 160p OIL SA,T,ME S MP7415844 1005 1F357 1105MN57160 820P TMS 1601 812 AY5-10133 74845 BOP 741548 465 4066 55p 1505 8228 2705 75114/15 11314 3005 74168451001, 1F13331 MN6221A600p051003-3 7485 00p 741%1 145 4089 125p16/1100 325pNE531 1405 8243 2805 25161,50250p 75121/22 140,COM80 300p 4wav 709 2532 3709 7486 lip 741654 1115 4093 24pLM301A 259NE544 1505 8250 8605 75150P 120p 11640217 4605 6 way OSP 7489 1705 7416668 120p UA2240 1S9355Op 1405 741$55 11p 90p 1943081 759NE555 185 8251 250p 2532-30 E7 75154 1R1602 304 8 way TIOP 74%4 20P 7415670 14094094 UAA170 Inv 905 74/583 1209 4095 755 LM310 1205 8253 7905 2 564 07 75182 10 way 1450 7491 355 741_573 7415678 SSOp 16556 455 ULN2003A 75p 18p 4096 705 LA4311 NE564 420p 8255 250p 2708 250p 75361 15 ZIF SKTs 25p 741%82 4005 75p 150505 74925 741574 169 409 2905 111318 203 8256 038 2716.+ 5v1250p 75363 7415884 4005 NE565 12013 ULN20613LL 29209 74935 615 741575 lip 40978 909 194319 215p 8257 4089 75365 1505 (TM -TOOL/ 365 NE566 1555 ULN29D2 200p 27128-25 £25 7494 741576 17p 7415087 4099 1005 1.3/1324 30p 8259 75451/2 61324pin 6005 NE567 1405 ULN2804 1505 ' 2764 85 MM58174 700p 74645 355 741583 31p 74S SERIES 4500 575p LM334Z 905 8271 f38 75453/4 720 28pin 81305 7486 40p NE570 410p UPC575H MSM5832000p 741585 405 4501 285 LM335Z 1405 27 2055 8279 4499 40pin E10 7497 90p 14..41 NE571 4009 UPCS92 05 MK3805 f T8.6 741686 1135 4502 60p LM339 605 8284 3505 74100 74502 30r NE592 60p UPC1156H E3 SOP 741590 22p 4503 469 Lm.3443 Op 74107 2211 74504 30p UPC1185H ES 741691 88p 4504 759LM358P 1305 LOW PROFILE SOCKETS BY TI WIRE WRAP SOCKETS BY TI 74109 269 741692 32p 74505 SDp 4505 400p X112206 3005 it4115pn 24 pin 74110 30P 741693 22p74508 60p4506 35p VOLTAGE REGULATORS X112207 376p 2::!nn 16p 24 Spin 265 18pin50p 24 pin 70p lOp 74111 665 741$95 40p 4507 355 FIXED PLASTIC XR2211 676p 14 pin355 20pin 8Dp 28pinsop 1799 16pin 22pin 32119 113pin 74112 741598 509 74511 50p4508 1305 X32216 117159 lip rps42Igrin4n 405 22pinOp 40pin 1005 50p lA r -ye 74116 7415 107 20p 74520 40p4510 413 -Ye XR2240 120p 74118 865 SV 7805 405 790546p 00235 865 74/5109 27p 74522 50p 4511 45p ZN414 80p MPSA93 40p 2522194 24 2SC2335200p 0A 400V 7130p 74119 805 6V 7806 40p 7906455 EID241 60p 25p 7415112 201 74530 40p4512 Op' 21419C 180p MPSUO6 54 2522224 20C26122005 25A400V400p 74120 1305 8V 7808 40p 7908485 BD242 6013 252369A 17p 7415113 20p 4514 1205 21423E 1335 MPSUO7 60p 31128 12(81 74121 Bp 74532 70p 12V 7812 4035 7912 505 BD379 7415114 22p 4515 110p 21424E 1305 605 MPSU45 90p 252484 24 35140 1205 74122 30p 74637 60p 15V 7815 41:15 7915 SOp 7415122 28p 4516 555 21425E 35 130380 605 MPSU65 714 252646 40p 1109 74123 36p 74574 750 18V 7818 405 7918455 35141 741S123 349 4518 40p ZN426E 30005p BD677 405 TIP29A 35p 212904/525p 35201 1105ME= 74125 30p 74885 3009 24V 741.$124 90p 4520 50p 7824 405 7924 45p11427E 59058F2448 365TIP39C 40p 2112906A 259 2.7V 33V 74126 305 74586 90p 5V 100mA 78105 35204 200p 7445125 24p 4521 30p 79105 90p BF2568 511p TIP0A 35p2 2129075 26p 400mW 9p 74128 30p 905 'ZN428E 490p 40 290 2505 74/5126 25p 745112 90p 22 6V 100mA 7810630p IZN1034E200p 8F257/8 32p TIP30C 40p 252926 9p 1W 15p 74132 30p 1205 40361/2 755 7415132 34p 745113 90p By 100mA 7810830p ZN104066705 80337 30p 71P31A 40p 2143053 24 28p 4526 805 40408 11055 74136 7415133 745114 90p 12V 100-nA 76112 305 791.12 SOp BFR39 25p TIP31C 45p 253054 55p 74141 585 30p 4527 805 215134 E23 40409 100 745124 300p 15V 100m6 78115 305 79115 505 8FR40/1 25p TIP324 40p 213055 35p TRIALS 74142 1755 7416136 219 4528 505 ZNA234 11609 40410 1005 7415138 745132 BER79 25p 110320 443p 253442 140p PI ATTIC 74143 2004 27p 160p4532 70p OTHER REGULATORS 40594 1 7415139 27p BFR80/1 25p 11033.6. 70p 253553 2409 74144 7120p 745133 000 4534 4005 40595 1205 74/5145 105 745138 110p4536 2705LM309K 1A 5V 140p 78905 9005 13F1196 1805110330 80p 253584 250p 40673 765 3A 400V 60p 74145 405 8FX29 405 253643/4469 7107415147 1209745139 120p4538 90p LM317KTO3 25011 78HGKC 600p 11934/1 90p 40871/2 1009 6A 400V 705 74147 BFX30 27p 213702/3 10p 6A 500V 74148 COp 74/5148 75p 745157 250p 4539 70p LM317T 100P 78H05KC560p TRANSM1ORS TIP340 120p Sep 7415151 BFX84/5 40p 11035A 213704/5 1op SA 4009 74150 505 40p 745158 195p 4543 755 LM337T 2259 78GUIC 204 124 769 7418153 AD161/2 455 BFX86/7 27p 110350 140p 213706/7 10p 741515 Up 40p 4553 24683 LM323K 3A 5V 460p 7900102259 DIODES 84 500V 969 745163 300p 13p BFX88 253708,9 10p 74153 36p 7415154 80p 4555 35p LM723 150164 Ara79HGKC 7005 BC107/8 27p TIP36A 140p 12A 400V 85p 745174 250p BFX89 213773 2005 74154 50p 7415156 301, 4556 35p ICL 7660 2005 BC109C 145 108p TIP36C 150p BY 127 125 1255009 1055 745175320p BFY51/2 213819 205 74155 38974/S156 313P 4557 300p 113501 BC117 205 21p TIP41A 50p BYX36300204 16A400V 1105 745194 320p 350p LM305AH 2605 40p 74156 4057415157 25p 4560 120p 80147/8 SP BFY56 339 TIP41C 55p 213820 0547 16A5 00V1305 746195 TL494 300p 78H12550p 213823 309 11P 74157 305 7415156 30p 40Lip 4566 160p BC149 105101'90 80p TIP42A 60p 0A90/91 128000 1305 745225 78 540 2255 902524 300p 213866 90p 911 74159 765 74/5160 36p 510p 4568 2500 BC157/8 10p BRY19 45p T1P42C 0A95 253902 704 91) 74160 40p 7415161 36p 74$241 300p 4569 1709 BC159 11p BSX19/2024p TIP54 168p 05200 OPTO ELECTRONICS 15p 9P 74161 40p 7415162 26p 746244 3099 4572 30p 801690 14130104 225p 110120 75p 253904 04202 10p TRYRI5TORS 8U105 213906 16p 74162 405 7415163 36p 745251 250p 4583 215777 40p 71178 56p BC172 1905 119121 75p 1N941 413 90p 214037 869 74163 4057415164 745257 250p 4584 405 OCP71 1805 TIL31A 120580177/8 17p80108 250p 110122 80p 15916 70 A 400V 1005 2N4123/4 27p 74164 4557415165 745258 250p4585 755 89912 1205 71132 55p80179 80109 225p TIP142 124 1614148 8A 600V 140p 74165 455741_5166 elp745260 40014 06060 1205 11181 90pBC182/3 10p130126 1505 T1P147 120p 2N4125/627p154001/2 5p 1605 70p 409 254401/3 25p 12A400V 74166 463741.5168 165 40086 905 88961 1205 111100 755 80184 11581.11804 1205 TIP2955 78p 154003/4 Op 164100V 1905 745261 300, 254427 90p 74167 15057415169 1130 40097 45p BC187 30590205 200p TIP4055 70p 154005 16A400V 184 745262 850p 254671 50p Op 74170 12057415170 70p 40102 OPTO ISOLATORS BC212/3 115BU208 200p TIS93 30p 154006/7 p 4E5 745373 4009 1409 215087 27p C10613 74172 250574/5173 569 40103 1705 BC214 BU406 145p Z7X108 12p 155404/5 149 MCR10135 391 745374 400p 11074 130p 111111 2 N5089 27p 74173 5057416174 40p 40105 1105 BC237 15125p BUX80 604 ZTX300 13p 155404/7 19p 27p 745387 250p MCT26 100p 711112 70p 255172 27p TIC44 74174 5857415175 40p 40106 405 00327 BUY69C 350p ZTX452 45p 1S920 90 253525 1305 745471 6999 MCS2400 190p 111113 70p 255191 909 74175 5097415181 11109 40109 00337 165E310 50p ZTX500 15p 745474 400, 100p 11074 240p 111116 70p 255245 2N4444 1805 74176 4997415183 1209 40110 BC338 16551.1802 400pZTX502 16p 30p 745571 6209 2755 MOC3020 1505 255401 2N5060 74177 455 7415190 31111 40163 805 BC461 259MJ2501 225p ZTX504 185 TN5064 3513 745573 9009 215459 30p 74178 7011 7415191 3.211 40174 SOp LEDS BC477/8 301, MJ2955 90p ZTX552 55p 2554 60 60p BRIDGE 74179 711113 7416192 28p 4000 cmos 40175 755 111220 Red10p BC516/7 405 9423001 225p ZTX652 60p RECTIFIERS 74180 40p 0.125' TIL222 G r 12p 805478 149MJ4502 400p ZTX752 70p 255485 36p 7415193 lbo 4000 111901934 755 PCB MOUNTING 74181 1165 7416194 TIL209 Red 10pTI1228Ye 15p BC548C 125MJE340 60p VN66AF 72p 255875 250p NU AA'S 36p 4001 105 40244 1005 1A 00V 711825 60p TI1211 Gr 12pRectangular 130549C 1lip65 VN1OKM 60p 256027 30p 195 7415195 36p 12p 40245 180p MJE2955 100p IA 100V 74184A 911p T11212 Yel15pLECHIR,G,Y1 305 8055713 VN66 80p 2N6052 300p 20p 7416198 18p 4007 505 40257 180p MJE3305 70p 14 400V 259 Son 12VDC 74185 9057415197 8C559C lOp MPF102 405 25697 25p 256059 325p 485 4007 Hp 40373 1130p 1A 600V 305 Coil %DT 2A 74186 470574/6221 1I1311 600p BCY70 lipMPF103/4 30p 25698 45p 2N6107 66p 600 4008 385 40374 1805 DISPLAYS 2A 50V 30p 24VDC 1805 74188 289974/$240 BCY71 225 21706A 30p 216247 190p 6 or 12VDC 650 4009 245 14495 3134 216254 2A 100V 365 74190 45p 660 01704 1400 IlLin 14; 60131 755 MPSA06 305 25708 30p 134 Cod DPDT SA 75241 4010 24 '4500 700p 66p 2A 400V 46p 74191 45p 7414/5242 DL707 040 14011111330 140p BD132 505 MPSA12 505 25918 45p 256290 550 4011 lip 14599 290p 3A 200V 600 24V DC 74192 46p "on 7750/60 2005 BD135/6 405MPSA13 505 25930 18p 2SC1306 104 74/5243 800 4012 lip 3A 600V 72p 240VAC 2009 74193 46p F40603 90PBergraph 235p 130139 405MPSA20 251131/2 36p 2SC1307 150p 6or 12VDC 7415244 500 4013 209 5509 90p 4A 100V95p 74194 405 00507 909 80140 405MPS.A42 505 251613 25p 2501957 Cod SPOT 10A 74195 7415245 70p4014 41IpEl=740925 £4 2$019691505 4A 400V115' 409 MAN3640 2005 1313189 6013 MPSA43 50p 2N1711 25p 7415247 50p 4015 405 2$02028 84 86 50V sop24V DC 74196 409 7216 8 £22 MAN4640 20059368 250p 130232 60p MPS556 32p 212102 lop 240VAC 225p 7415248 560 20p 2SC2029 200p 6A 100V 1005 74197 40p 556158815705 9370 300p BD233 75p MP5470 50p 2N2160 3505 7415249 40174016 74C926 £5 2SC2078 160p 56, 4060 1205 PLEASE ADD 40p p&p & 15% VAT TECI I NON I ATIC I TI) (Export: no VAT, p&p at Cost) \ RH. ORDERS TO: 17 BURNLEY ROAD. LONDON NAN 10 I LI) Orders from Government Depts. & Colleges etc. welcome. SHOPS A 1.: 17 BURNLEY ROAD. LONDON N11 10 (7 el: (11-452 1500. 01-450 6597 Telex: 9228001 Detailed Price List on request. 305 FD(; \ Rl R() I ONOOS 112 Stock items arc normally by return of post

ETI AUGUST 1983 17 ne of the ironies of life is that the largest single factor in determining how well 0any sound system performs has nothing to do with the system itself: OCTAVE it is the room. Now you could adopt an all -or - nothing approach and take a pneumatic drill to your listening room, to get rid of all those resonances, throw out all the 3 EQUALISER furniture, because it's too absorbent, and keep everyone else out of the listening area, because clothes absorb sound too (and relatively high and will therefore bodies, so it's no good asking your cause significant modification tothe friends to go naked). However this overall phase linearity as well as the could lead to a certain amount of frequency response when cut or In order to illustrate the principle of boost is applied. I have seen many operation of the graphic equaliser we domestic unrest, and anyway, first need to consider the operation of a would be impractical at a large otherwise high quality systems simplified version of a single stage, as il- scale concert. degraded significantly by the lustrated in Figure 1. Here, the input A less radical approach that has excessive use of 4 -octave equalisers signal is fed to the non -inverting input of and we do not recommend the an op -amp through a 10k resistor. A fewer disadvantages is to tailor the potentiometer is connected between the response of the electronics so that incorporation of these units into a non -inverting inputs with its wiper going the overall response of the audio high quality system unless a specific to signal common (ground) via a net- system plus the room is neutral. need is apparent. Nevertheless, work represented by Z. Here, a series - when modification of the frequency resonant circuit is employed. Feedback This is most usually done with a is provided between the op -amp output graphic equaliser. response is required, no matter how and the inverting input. While octave equalisers do have drastic or how modest, a 1 -octave graphic equaliser is an almost ideal INPUT some use, most equalisers supplied 10k OUTPUT for domestic use are pure way of doing this. gimmickry. If you're taking your Each channel of the equaliser is equalisation seriously, the only real controlled by a separate slider option is a -is-octave device, which, potentiometer so the array of pots gives an approximate indication of EFFECTIVE by pure coincidence, is what we're POTENTIOMETER the response inserted. IMPEDANCE DUE TO about to describe here. PARALLEL IMPEDANCE CONNECTIONS. The ETI i-octave equaliser is of NETWORK -- OF SLIDERS sufficient quality not to seriously Design SERIES RESONANCE degrade the sound of a high quality Each filter is formed by a series CIRCUIT system. It should be noted however, resonant network incorporated into Fig. 1 that the use of any is -octave the feedback loop of a high quality equaliser will affect the performance operational amplifier. In this case The input resistor forms a potential of the system simply because it is in we have used the NE5534N. divider with part of the potentiometer circuit. Each of the filters has a 'Gyrators' are used to simulate

Circuit diagram of the NOTE main section of the IC1,2 ARE NE5534N Graphic Equaliser Cs 1C3-9 ARE TL074 CI 470n Cl 47D/25 V IN INPUT OUTPUT NE5534N R7 RI R2 1000 Re 47k 100k 01-tkW-N-AA/0--NOW- R6 10k C2 R3 R4 RV1 10k LOG 470/25V 1k 100R

0012 11 16-RV2 C12 ,r c C36 s Wt., 1500 270

C9 1900 R9 R13 C17 017 PS 1k 66n 10 PS

014 RIO 20k 2200 PS RIO 220k

17 V21 C42 9 Cm ..C". -I.3308 RVS Cu ...L 8.12 1 RV3 -

2200

ETI AUGUST 1983 18 PROJECT GRAPHIC Is your listening room/concert hall dulland lifeless? Or does it echo and ring like the WhisperingGallery? David Tilbrookcomes to the rescue witha project that will help get yourresponse into shape.

HOW IT WORKS (from the op -amp + input to the wiper) can be set to cover a desired frequency Figure 3 shows the general circuit of and the impedance Z to common. The range. The potentiometer then sets gain the gyrator used inthis project. The feedback resistor also forms a potential or attenuation of the stage at the centre amount of inductance 'generated' by divider with the end of the pot from the of the chosen frequency band. thiscircuitisgiven by the simple inverting input and the impedance Z to The technique just described above equation: ground. can be used whenever it is desired to in- L = 1k x 220k x C, in Henries If the wiper of the pot is set to mid - corporate a relatively large number of where the value of C, is in Farads travel,the attenuation of the input filters into the signal path as in graphic The equivalent circuit of the gyrator signal due to the potential divider is equalisers or tone controls. The filter is shown in Fig. 4. The series resistance is compensated by the gain of the op -amp networks need not be band pass or notch equal to the 1k resistor while the 220k and the overall gain from input to out- filters, simpler bass and treble controls resistor becomes the parallel resistance put is unity. If the pot wiper is now mov- can also be used. of the coil. This value is high enough not ed toward that end of the pot connected Once this basic configuration is set to affect circuit operation drastically. to the op -amp's inverting input, the gain up, all that remains is to design the filter The resonant frequency of this filter is of the stage is increased as the feedback networks. As mentioned before, series given by the standard formula:

ratio is reduced owing to a reduction of resonant networks were used since these 1 the impedance from the op -amp's inver- give the required characteristic of low F = in Hertz ting input to common. At the same time impedance at the resonant frequency. In 2/rN/LC less attenuation of the input signal oc- their simplest form these networks con- The general circuit, simplified, of the curs as the impedance from the non - sistofaninductor,capacitorand Third -OctaveGraphic Equaliser is inverting input to common is decreased. resistor in series. At the resonant fre- shown in Fig. 5. IC1 is simply a variable The stage will have gain, maximum gain quency, the impedance of the circuit is being determined by the impedance of gain stage which also provides some in- equal to that of the resistor assuming a put buffering. IC2 is the filter stage with the series resonant networks. If this is perfect inductor and capacitor were us- a group of 28 gyrator circuits, all con- low, gain will be high. Series resonant ed. To eliminate the inductor an op -amp networks exhibit very low impedance at circuit has been used to simulate the nected in parallel, in the feedback cir- cuit. Commencing at a centre frequency resonance,risingeithersideof that characteristics of an inductor. Such a frequency. circuit is called a 'gyrator'. of 31.5 Hz, each gyrator filter has a Q When the wiper of the pot is moved The gyrator circuit can provide both chosen such that its bandwidth covers toward the non -inverting input of the the inductance and the series resistance one-third of an octave. Thus the upper op -amp, the attenuation due to the in- required in the network so this can simp- and lower the 3 dB points of adjacent put potential divider is increased. The ly be placed in series with the capacitor filters 'touch'. A total of 28 filters are re- gain of the op -amp is decreased at the to form the required resonant circuit. quired to cover the audio frequency same time as the feedback ratio is in- band. Filters are not placed on the band This is shown in block diagram form in limits of 20 Hz and 20 kHz as they are creased because the impedance from the Fig. 2. inverting input to common is increased. not really required. To reduce the IC Once again, the overall gain of the cir- count a set of seven quad op -amps TcC (TL074s or uA774s) are used for the cuit is a function of the impedance of gyrators. the series resonant circuit, but this time z the gain is at a minimum - in fact, at- Slide pots are used to set the gain or tenuation occurs. attenuationinsertedforeachthird - By choosing a suitable Q for the GYRATOR octave band as itis easy to see, at a series resonant network, the bandwidth glance, how much gain or attenuation Fig. 2 BASIC GYRATOR CIRCUIT has been set and, as all the pots are lined up in parallel across the front panel, one Fig. 3 can instantly see the total modification made to the audio system's frequency response.

EQUIVALENT CIRCUIT OF GYRATOR IN FIG.2 Fig. 4 Fig. 5

ETI AUGUST 1983 19 PROJECT:Graphic Equaliser

the inductors necessary for the ...ARy50-1--... +12V TO PIN 4 IC3 C70 series of band-pass filters so there 1k0 10n are no coils to wind. The gyrator is 12V TO PIN 11 IC3 R86 covered in more detail in the How 1k0 it Works section, but the main +12V TO PIN 4 1C4 C64 10n R67 C71 problem associated with this FS1 lkO 10n approach is caused by phase shifts 12V TO PIN 11 IC4 occurring in the op -amps used in 3 the gyrators. The basic principle of a +12V TO PIN 4 IC5 gyrator is to invert the phase response of a capacitor to simulate MAINS 12V TO PIN 11 105 the characteristics of an inductor. R70 The problem is that all amplifiers 1k0 +12V TO PIN 4 IC6 introduce a phase shift which C0n3 1k0 1 increases towards the extremes of LINK 12V TO PIN 11 IC6 -SEE TEXT the frequency response. For this R72 reason, care must be taken when 1k0 choosing op -amps for use in +12V TO PIN 4 IC7 C74 gyrators at the top end of the 1k0 10n frequency spectrum. This problem is 12V TO PIN 11 IC7 R74 accentuated when the Q of the 1k0 filters concerned is increased. Since F151c7:-....+12V TO PIN 4 IC8 the Q of the filters must be higher 1k0 10n NOTE: in a 4 -octave equaliser, an op -amp IC10 IS 7812 12V TO PIN 11 IC8 IC11 IS 7912 R76 with greater phase linearity at high D1.4 ARE 1N4001 1k0 LED1 IS ANY RED LED frequencies must be used. COMPONENTS MARKED WITH ?-iy:i77 0-1----1.- +12V TO PIN 4 IC9 ARE OPTIONAL C76 Fortunately, op -amps with the 1k0 10n desired characteristics are not IS SIGNAL EARTH C79 12V TO PIN 11 IC9 difficult to obtain and we are using 407 R78 IS CHASSIS 16V 1k0 the TL074 or uA774. These are both +12V TO PIN 7 ON quad FET op -amps with almost IC1 AND IC2 identical performance and are -12V TO PIN 4 ON capable of excellent results in the R80 Cu C78 IC1 AND IC2 F4u0+C87 1k010n 10n circuit, even in the top -most filter. 16V Circuit of the power supply for the Graphic Equaliser. Earthing In any large multi -component impedance path to earth through supplier for a suitable type. In the audio system, earthing is a the rest of the equipment for safety end, we used Siemens continuous nightmare because of reasons: if there isn't, you're asking polycarbonate layer types from hum loops. The theory says that the for a nasty shock. Note also that Cricklewood for all the capacitors entire audio circuit should be you must use insulated audio input above 10n in value, and mixture of earthed at only one point. and output sockets, and be careful these and polystyrene for those However, adding an extra earth not to inadvertently connect the under 1n0. Ours were all 5% types connection can sometimes cure a signal and mains earth in any other or better, and we'd strongly suggest hum that you've spent many hours way - watch how you secure the that you use 5% tolerance or better chasing round the circuit - this is PCB to the case, for example. for all the capacitors in the gyrators. one of those occasions when the We've designed the PCB so that it best approach is to leave it like that Capacitors should accommodate most types (but keep your fingers firmly One possible area of trouble is you're likely to want to use. crossed), hope it holds while the in finding a supplier for the band is playing, and forget about it capacitors. If you look at the Parts Next month we will give afterwards... List, you'll see that lots of the constructional details of the The other problem is deciding capacitors are in the E12 series: we Graphic Equaliser, including exactly where this one earth should hadn't realised how many suppliers details of a -super specially be in the first place. Some people had switched to supplying just the designed case from Newrad say the very start of the signal path E6 series until we tried to locate a Instruments. - or, at least, as close as you can get to it. Others say that it should be at the power amp input. But everyone agrees - it's definitely never at the graphic equaliser. OK, then, what connection should there be between the mains earth and the graphic equaliser electronics? Some opt for a capacitor (100n is a reasonable 'value); others use a resistor (10 to 100R). We've left this up to you. However, all agree that there must also be a very low This is the completed PCB - more details next month. 20 ETI AUGUST 1983 MAIL ORDERS: I /S4 Unit 1, Hill Farm Industrial Estate, !". Rapid Boxted, Colchester, Essex C04 5RD. ACCESS AND TELEPHONE ORDERS: BARCLAYCARD 'Electronics Colchester (0206) 36412. WELCOME LM339 45 NE566 140 LINEAR LM3911 120 TL064 96 HAPG AA//E LM348 60 LM3914 175 95E567 100 TL071 30 CABLES CAPACITORS LM358 50 LM3915 195 95E570 370 71.072 50 555CMOS 80 20 metre pack single core connect- PP3 battery clips . . 6 ICL7106 790 LM377 170 LM13600 105 NE571 370TL074 96 Polyester, radial leads. 250v. 0280 556CMOS 150 ICL7611 95 ing cable ten different colours.65p Red or black crocodile clips . 6 9LM380 65 MC1496 68 95C4136 55 19TL081 2 type: 0.01, 0.015, 0.022, 0.033 - 709 25 . ICL7621 180 9LM381 120 9FIC4558 Speaker cable . . 113p/m Black pointer control knob . 15 6p; 0.047, 0.068, 0.1 - 7p; 0.15, 19741 MC3340 135 60TL082 41 14 180 Standard screened . 16p/m Pr Ultrasonic transducers 350 ICL7622 LM382 120 911F1005 350 SL480 17071.064 95 0.22 -95;0.33, 0.47 - 13p; 0.68 - 748 . 35 . . 96V Electronic buzzer ICL8038 295 LM384 130 M L922 400 51_490 250 Twin screened 245/m 60 20p; lu - 23p. 350 TI.170 50 9400CJ 200 2.5A 3 core mains . 23p/m 912V Electronic buzzer 65 IC1.82114 LM386 65 M L924 195 SL76018 150 U42240 120 Electrolytic, radial or axial leads: AY -3.1270 720 10 way rainbow ribbon 655/rn 9P82720 Piezo transducer. 75 ICM0224 785 LM387 120 ML925 210 96576477 380 ULN 2003 85 0.47/63 V, 1/63V, 2.2/63V, 4.7/63V, AY.3.8910 370 20 way rainbow ribbon 964mm 64 ohm speaker . 70 1CM7555 80 LM393 100 ML926 140 SP8629 250 U1.52004 90 1205/m 10/25V - 7p; 22/25V, 47/25V- Sp; AY -3.8912 540 19LF351 45 10 way gory ribbon . 313p/rn 964mm 8 ohm speaker . 70 LM709 25 ML927 140 TBA120S 70 XR2206 290 100/25V - 9p; 220/25V - 145; CA3048 60 LF353 85 LM711 60 ML928 140 20 way grey ribbon . . 80p/m 20mm panel fuseholder . 25470/25V - 22p; 1000/25V - 305; 9 CA3080 65 THAW° 7525414 100 LF356 90 LM725 350 M L929 140 TBA810 96ZN423 "-2200/25V - 50P. CA3089 190 360 135 LMIO LM733 75 MM5387A 465 TBA820 70 ZN424 135 Tag end power supply eleotrolytion: CA3090A0 375 LM301A 25 REGULATORS POTENTIOMETERS LM741 14 NE529 225 TBA950 220 ZN425E 350 2200/40V- 110p; 4700/40V -1505 CA31305 85 LM311 70 LM 747 60 NE531 150 TDA10013 320 ZN426E 2200/63V . 140p; 4700/63V 230P 9CA31406 36 LM318 120 330 3079 L05 65 Rotary. Carbon track Log or Lin LM1458 40 NE544 205 911341022 49025427E 650 781.1278L05 791.12 1K - 2M2. Single 32p. Stereo 855. Polyester, miniature Siemens PCB: CA3161E 100 111324 40 30 65 LM2917 200 95E555 16 TDA1024 125 ZN428E 480 78L15 65 10.2n2,3n3, 4n7,6n8,1017, 15n, 7p; CA3189 290 LM334Z 100 30 79L15 Single switched 80p. Slide 60mm LM390Q 45 95E556 45 TL061 40ZN459 285 7805 40 travel single Log or Lin 5K - 500K 22n, 33n,47n,68n, 8p; 100n, 9p; 9CA3240E 110 LM335Z 125 35 7905 9LM3909 70 NE565 110 TL062 60251034E 200 77881152 35 7912 40 63p each. 150n, 11p; 22017,13p; 330n, 205; 35 7915 40 Preset subrnin. hor. 100 ohms -1114 470n 2135;680n, 29p; lu 33p; 2u2, 500. BC517 40 85337 40MPSU56 60 ZTX108 8 2N3055 50 LM309K 130LM723 35 7p each. TRANSISTORS BC547 7 BER40 23 TIP29A 30 ZTX 10912 253442 120 LLM3m31177T K 270SPECIAL3,FF5E/R I Cermet precision multiturn, 0.75W Tantalum bead: BC548 10 BER80 23 TIP29B 55 ZTX30014 9253702 6 %" 100 ohms to 100K - 886 each. 0.1, 0.22, 0.33, 0.47, 1.0 @ 35V AC125 35 BC149 9 BC549 10 9BFR81 20 TIP29C 37 ZTX301 16 253703 9 L51323K 350 only 3905 each. 12p. 2.2, 4.7, 10 @ 25V - 205; AC126 25 BC157 8 BC558 10 BFX29 25TIP304 35 ZTX30215 9253704 6 TRIACS 400V 8A 6515/16V - 305; 22/16V - 27p; 33/ AC127 25 8C158 10 BCY70 18 BF X84 25 TIP3OB '50 ZTX30417 253705 9 400V 164 9516V -455;47/6V - 275;47/16V - 9AC128 20 8C159 8 BCY71 18 BF X65 25 TIP30C 37Z7X34130 2N3706 9 DIODES 400V 4A 50 135100 2570p; 68/6V - 40p; 100/10V - 90P. AC176 25 BC160 45 BCY72 18 BFX86 28 70.31A 35 ZTX50015 253707 10 Car. disc. 225-0 Olu 50V, 3p each. AC187 22 8C168C 10 BD115 55 BF X87 25 TIP31C 37 ZTX501 15 253708 10 BY127 12 9154001 3 Mallard miniature ceramic plate: AC188 22 BC169C 10 BD131 35 BFX88 25 TIP324 35 01550215 253709 10 0A47 10 154002 5 JUMPER LEADS 1.8pF to 1005F 6p each. AD142 120 60170 8 BD132 35 BEY50 23 TIP32C 0490 8 154006 7 37 ZT%503 18 253772 170 Polystyrene, 5% tol : 10910005, 69; AD149 BC171 10 80133 50 BFY51 20 TIP33A 0491 7 154007 7 80 50 ZT X50425 9253773 195 Length 14pin 16pin 24pin 40pin 15004700,89;6800 0.012u, 105. A0161 40 8C172 8 813135 40 BFY52 23 TIP33C 75 2N697 20 9253819 18 0A200 8 155401 12 Sole ended DiPlheeder plug/ jumper AD162 40 80177 18 BD136 30 BF Y53 32 TIP34A 60 04.202 8 155404 16 24 ins. Trimmers. Millard 808series: 2-10 25698 40 2N3820 40 145 165 240 380 pF, 22p; 2-22pF, 30p; 5.5-65pF,3155 AF124 60 BC178 18 80137 30 BEY55 32 TIP34C 85 25706A 20 253823 65 1N914 4 1N5406 17 Dble ended DIPlheader plug) jumper AFI26 50 8C179 18 80138 30 BFY56 32 TIP35A 105 2N708 20 253866 90 9154148 3 400mWzen 6 6 ins. 185 205 300 465 AF139 BC1B2 9130139 BRY39 TIP35C 40 10 35 40 125 25918 35 253903 10 12 ins. 195 215 315 490 BRIDGE 2A 200V 40 AF186 70 9BC183L 8 1%80140 35 BSX20 20 TIP36A 125 251132 22 253904 10 OP TO 24 ins. 210 235 345 540 RECTIFIERS2A 400V 45 AF239 75 BC183 10 80204 110 BSX29 35 TIP36C135 25161330 253905 6 36ins. 230 250 375 595 A 100V 80 BC107 10 BC183L 10 60206 110 BSY95A25 TIP41 A 45 252218A 45 253906 10 25 way D Connector jumpers 1.3mm red 7 95mm red 7 6A 400V 95 BC1076 12 BC184 10 BD222 85 BU205 160 TIP42A 45 252219A 25 254037 45 113ins. long single ended male 4955. 20 VM18 DIL 0.9A TIP120 I.3rnm green 10 95mm green 10 ISBCIOB 10 BC184L 7 85180 35 BL1206 90 10 1'1ai4 5°00 1V . 180 252221A 25 254058 1.3mm yellowl 0 95mm yellow10 18ins.long single ended f /male 525p 35 200V . 50 BC108B 12 BC212 10 6E182 35 5U208 170 TIP121 90 252222A 20 254060 10 Clips to suit - 3p each. BC108C 12 BC212L10 BF184 25 MJ2955 99 T1P122 90 25236825 2N4061 10 Rectangular TIL32 40 111.13C109 10 BC213 10 BF185 25 MJE340 50 TIP141 98 252369 16 254062 1 EPSON PRINTERS 9 red 12 TIL78 BC1061C 12 802131. 10 8F194 12 MJE520 65 TIP142 98 2192484 25 2N5457 36 40 green 17 9T1L111 60 BC114 18 BC214 10 8F195 12 MJE521 95 TIP147 110 25264645 255458 36 BC115 22 19BC214L 8 BF196 12 MJE3055 70 TIP2955 60 25290420 255459 30 yellow 17 ORP12 85 Latest generation printers from 9TIL38 90 BC117 18 80237 BF197 12 MPF102 40 TIP305555 25 2904A 20 255485 36 40 TIL100 Epson. Logic seeking, bi-directional, BC119 35 BC238 14 85198 10 MPF104 40 TIS43 40 252905 22 2N5777 45 2N5777 45 Dual colour 60 bit image printing, 9 x 9 Matrix, Seven segment displays, BC137 40 BC308 12 BF199 18 MPSA05 22 TIS44 45 252905A 22 256027 30 Auto underline, Centonix 8 Bit Corn cathode Corn anode Parallel Interface as standard. BC139 40 80327 14 6E200 30 MPSA06 25 TIS90 30 2N290625 40360 40 BC140 28 BC328 14 91352448 22 MPSA12 TIS91 30 50 0L704 0.3" 95 DL707 0.3" 95 30 252906A 25 40361 9E513500 END507 BMW 100 CPS 80 column BC141 30 BC337 14 8F245 30 MPS455 30 VN1OKM 45 2N2907 25 40362 50 100 Tractor feed . . 80142 25 80338 14 8E25613 45 MPSA56 30 VN46AF 75 252907A 25 40408 70 0.5" 100 BC143 25 8C477 30 13E257 32 MPSUO5 VN66AF 85 111.313 0.3"115 T1L3120.3"115 55 2N2926 9 5X80 160 CPS 80 column BC147 8 BC478 30 8F258 25 MPSUO6 55 VN88AF 95P253063 23 TIL3220.5-115 T1L3210.5-115 Tractor Feed . . . 098.00 BC148 8 BC479 30 8E259 35 MPSU5560 ZTX107 8 2N305455 LCD: 35 digit 580p. 4 digit 6205. Carriage f7 per printer.

MIN. D CONNECTORS SOLDERING IRONS RESISTORS PCB MATERIALS BOXES 9 way 15 way 25 way 37 way Aluminium Plugs solder lugs 609 859 125p 170p 'W 5% Carbon film El 2 series 4.7 Alfac transfer sheets - please state 3 x 2 x 1" 65 Right angle 1209 1809 2409 350p Antes CS 17W Soldering iron 460 ohm - IM. . . 1p each. type (e.g. DIL pads etc.) 45 Plastic with lid 4 x 2%4 115" 95 Sockets lugs 90p 130p 1955 2905 2.3 and 4.7mm bits to suit . 65 1515 5% Carbon film 512 series 4.7 Dalo etch resistant Pen 100 & screws 4 x 25x 2" 95 Right angle 1605 2105 290P 4405 CS 17W iron: 450, elernent, 210 ohm to 4M7 . . . 2p each. Fibre glass board 3.75x 8" 63 3 x 2x I" 55 6x4 x2" 120 Covers 1005 90p 100P 1105 Antes XS 25W . . 480 1415 1% metal film E24 series 10 Fibre glass board 8 0 12" 200 45x 3x 15"88 7x51s254" 165 3.3 and 4.7mm bits to suit . 65 ohm - 1M Sp each. Ferric Chloride crystals 100 7x 2"160 8x6 x3" 205 Solder pump desoldering tool. 480

CCANEC TORS P 010613 30 Spare nozzle for above . . 70 4016 20 4034 140 4054 78 4081 12 40193 654528 45

10 metres 22swg solder . CMOS SCR 400V 8A 70 100 4017 30 4036 249 4055 80 4082 12 4502 604529 150 DINPlug Skt Jack Plug Skt 400V 12A 95 4018 45 4039 280 4059 430 4085 48 4503 324532 60 2 pin 9p gp 2.5mm 105 10P 4000 10 4019 25 4040 ao 4060 42 4086 50 4507 354534 4001 10 400 3 pin 125 10p 3.5mm 9p9p 4020 42 4041 40 4063 80 4089 125 4508 110 4538 60 VERO 4002 12 5 pin 13p 115 Standard165 20P 4021 40 4042 38 4066 22 4093 18 4510 454543 50 4006 50 Phono105 12p Stereo 24p 259 4022 45 4043 40 4067 225 4094 68 4511 40 4549 360 4007 14 1mm 129 139 4mm 18p 17p VOICE SYNTHESISER, VEROBLOC 4 . 350 4023 16 4044 40 4068 14 4095 65 4512 40 4553 215 UHF IC131 Connectors: Size 0.1 matrix: 4008 36 4024 33 4046 40 4069 13 4097 290 4514 115 4555 35 4009 24 PL259 Plug 40p. Reducer 14p. Now your corn 2.5 x 1 22 4025 12 4047 35 4070 13 4098 70 4515 115 4556 35 n talk. 4010 24 S0239 square chassis skt 313P. The GI SP0256 ....even processor 2.5 x 3.75 4026 75 4048 38 4071 13 4099 70 4516 55 4559 390 4011 10 20 $02395 round chassis skt 405. is able through stored program to 2.5 x 5 85 4027 4049 21 4072 13 40106 404518 40 9560 140 IEC 3 pin 250V/64. 4012 15 4028 synthesize speech. Allophone 3.75 x 5 95 40 4050 21 4073 13 40109 110 4520 50 4584 35 Plug chassis mounting . 4013 20 4029 45 38p (extended phoneme) system gives VQ board 160 4051 42 4075 13 40163 60 4521 130 4585 60 Socket free hanging . . . 60p Veropins per 100: 4014 454030 14 4052 48 4076 45 40173 100 4526 60 4724 140 unlimited vocabulary. 4015 40 125 Socket with 2m lead . . 120p Emily interfaced with any digital Single sided 50 4031 4053 48 4077 14 40175 75 4527 50 Double sided . 60 system; ten TTL compatible sig- LS75 nals are used to select the allo- Spot face cutter 105 1.020 12 20 LS123 34 LS160 35 LS197 45 LS353 60 S..% I Ti,,H LS IT LS76 17 phones. Pin insertion tool . 162 LS21 12 LS125 24 LS161 35 LS221 50 LS365 28 Wiring pen and spool . LS22 12 LS73, 17 LS126 25 LS162 35 LS240 60 Submin toggle: SP0256 . 770p. Data: 50P 310 LS366 28 1....500 11 LS83 35 SPST 55p. SPDT 60p. DPDT 65p. Spare spool 75p Combs . 6 LS26 14 LS132 35 LS163 35 LS241 55 LS367 28 LS01 11 LS85 48 Miniature toggle: LS27 12 LS136 26 1.6164 40 LS242 55 1.5368 29 LSO2 11 LS30 12 LS86 16 LS138 30 LS165 55 LS243 56 LS373 58 SPDT 80p. SPOT centre off 905. 611653 320 6852 240 8228 22() LSO3 12 LS32 13 LS90 24 LS139 30 LS166 60 LS244 55 LS374 60 DPDT 905. DPDT centre off 1005. MICRO 6502CPU 325 495 6875 8251 250 LSO4 12 LS37 14 LS92 25 1.0145 70 LS170 75 LS245 70 L6375 ' Standard toggle: 6522 VIA295 6880 43 100 8253 390 LSO5 12 LS38 15 LS93 24 LS147 150 LS173 60 LS247 48 LS377 60 SPST 355. DP07185 6532 570 B1LS95 85 8255 225 1.808 12 LS40 13 LS95 38 LS148 75 LS174 45 LS251 28LS378 57 Moisture DP07 slide 12p. 6551 ACIA 650 85 81 LS96 8259 390 LSO9 12 LS42 28 LS96 95 LS151 38 LS175 45 LS257 32LS390 45 Push to make 14p. 2114L2 75 6800 CPU 220 81 LS97 86 MC1488 55 LS10 12LS47 35 LS107 40 LS153 38 1...5190 35 LS258 32LS393 40 Push to break 22p. 2716 205 6802CPU 250 8080A 250 MC1489 55 LS11 12 LS48 45 LS109 21 LS154 75 LS191 35 L.5259 55 LS399 156 Rotary type 119W.14014 stop. 2532 290 8809CFU 620 8085AC340 0804 CPU 290 LS12 12 LS51 14 LS112 21 LS155 33 LS192 35 LS286 20 LS641 78 1P12W, 2P6W, 354W all 555 each. 2732 290 6810RAM 115 8156 350 280A PIO 260 LS13 19 LS55 14 LS113 21 LS156 36 LS193 36 LS273 58 LS670 OIL switches: 2764 540 6821 PIA110 8212 110 280ACTC 135 260 LS14 30 LS73 18 LS114 22 LS157 26 LS195 32 LS279 30 4SP8T 805 6 SPST 80p. 8SPS7 4116P20 70 6840 360 8216 100 Z80ASIO 900 LS15 12 LS74 17 1.5122 35 L6158 29 LS196 45 38 1005. 5101L-1 220 6850 110 8224 120 ZBOADMA 1150 LS283 7413 17 7444 85 7483 30 74122 38 74161 46 74190 23 7446 58 COMPONENT KITS 7414 7485 60 74123 38 74162 46 74191 7416 19 7447 36 7486 19 74125 33 74163 46 74192 SOCKETS 7400 11 7417 43 AnIdeal opportunity for the beginner or the experienced constructor 19 7448 7489 180 74126 33 74164 46 74193 7401 11 7420 14 7450 14 to obtain a wide ramp of components at greatly reduced prices. 'AW 5% 7490 19 74132 30 74165 46 74194 7402 11 14' Resistor kit. Contains 10 of each value front 4.7 ohms to 111 (total 7421 19 7451 7491 34 74141 54 74167 150 74195 7403 12 7422 19 7453 14 7492 24 74145 48 74170 115 74196 of 650 resistors) ...... 530 7404 12 7427 18 7454 14 7493 24 74147 75 74173 58 74197 Ceramic Cep. kit. 5 of each value - 225 to 0.01u 1136 calla) . . 370 Polyester Cap. kit. 5 of each value from 0.01 to laF 165 c490 7405 14 7428 25 7460 14 7494 33 74148 60 74174 53 74198 75 19 13 7472 22 33 Preset kit. Contains 5 of each value from 100 ohms to 1M (total 7406 7430 7495 74150 48 74175 4574199 7407 19 7432 20 7473 24 7496 38 74153 38 74176 35 Nut and Bolt kit (total 300 Items): 1805 7408 13 7433 20 7474 19 7497 86 74154 17 74177 42 7409 13 7437 23 7475 26 74100 78 74155 25 884 Y." bolts 50 6BA washers 50 884 38 74179 75 7410 13 7438 24 7476 25 74107 22 74156 36 25 884 W' bolts 25 4BA 14" bolts 50 SBA Weepers. 74180 38 7411 15 7440 14 7480 45 74109 74157 60813A nuts 25 6BA IS" bolt.. 24 28 74181 100 7417 17 7442 30' 7482 85 74121 24 74180 55 74182 56

'ORDERING INFO. All components brand new and full specification. All prices exclude VAT. The Rapid Guarantee Please add to total order. Please add 50p carriage to all orders under15 in value. Sendcheque/ P.O. or AocossNisa number with order. Our detailed catalogue costs 45p (free with orders over * Same day despatch * Competitive prices £101. Callers most welcome. Telephone orders welcome with Access or Visa. Official orders * Top quality components * In-depth stocks \ accepted from colleges, Schooy_, etc .. Callers most welcome, we are ow) Monday to Frit_r.

ETI AUGUST 1983 21 6.30upc ' 400/3V 32p 2.5 x 17 2.990 CONNECTORS R3 9x50218" 630mA PCB RELAYS 252102:39p 254416.4 1.80 256126 75p BC1674 10p BC409 350 . 3.75 x 17 26044C 3.85 Solder Type 3.15 170 10P24064010 252217 399 294220 752 256129 lip BC1676 132 SC413 266 IDEAL AS MAVIS MANY MORE 4.793r 17 MW 252215 33p 952 4.93 R4 118143" : 130OrnA 254221 266130 936 BC188 102 CARBON RIM 40222E95cm CAPACITORS 5'123 C°4636,t3 BC4I4 2E2 VO Board 1.92 9 way 80p 3.85 2622184 252 254222 972 256131982 801685 10p 60415 302 5% a* CANS STOCR: 122 114POT 1,19" PY 252219 272 2144223 972 -' Dip Board 3.90 15 way 1.03 298132 83p BC1613C 102 80416 302 HI STAB:WTI) 1412260 34 91-1 MON° 5511075+399"IA 17p 10p22 2.75 2522194 262 254224 998 104 Track Cutter 1.48 25 Way 1.60 4.751.6A 17p 10p 258133 1.14 BC1139 15p' 80418 35p 47nF 390 in 12v 28512 252220 226 254234456 298134 1.36 13C169B 144 80440 9W 5211 22 1044 Inserter 1.79 37 way 2.50 56 1398645" 2A, 17p 10p 370 44 2.75 252221 24 254236 456 258212 3.27 8C1690 102 6C441 390 ,W 524 296 t 541 452 Pins 55p Farn54 7.353.158 17p 10p 49 115012 2522214 242562531.215p 1.45 16P scpeo 17p lw 624 ao 220nF 55p 100100mA 252222 9 way 9911 R7 15,844" 4A 172 10p 2.95 24 254236 256254 1.55 13C1704 172 BC451 33p 2W 624 122 15 way 1.75 27422224252 13,0.6V, 9-0-9V. Ver:P...329 5A IDP 1000VDC 12.0.125, 7.75 I7 ep460011 252223 2.60 Pen'41 4 Spool -4 3.35 25 way 2.05 6.34 25424024239 3.005 '26SCC1M96306 995P5p BCBC41770C°6 11478 BC8C447198 METAL FILM 624 lip 10p3.04 30026P PLASTIC 16-0-15V 94 Spare Spool 752 37 way 3.30 2522234 4.15 254248 14 2SC1307 1.80 BC171 122 s,c5,644 19TRA HI STAB InF . 42 282 VEROBOXES 10A I7p 10p 252368 Combs Op Angled PCB sap* made 24 254249 17p 25C1923 402 8C171AI5P 13C517 400 (ATM LOW 4.7.758 29p 694 252369 192 NOISE 25w Male 2.45V1 302x1" 254250 Op 2502078 1.70 8C17113 14 160547 130 104F 3111 1%" Slow Fast 2523694202 254258 80172 12p 0.4W 1051 TO 222F, 33ni 372 061°61/ 255=MEE25w Female 752 25,149 .3.50 0125476142 0.1240-12V 54100mA Guaranteed 252405 58P 254266 44 -3.75 LIC1724 151, 1M 470 2.96 292410 1.15 25/50 80 5475 14 alp 2.65 V2 120580x 19p 15p minimum 500 254275582 25.182 4.29 8C1728 15P 12p 2%524 52 1001F Covers 292411 805443 44 0.15+0.154 DIE SPST 99P 35mm 90p250rnA charges 3.00 25428432p 230134 3.50 BC172C 102 805484 131, 1% E24 Op 220n1, 750 265 4 way HP2(1.24 2.39 2142483 672 V3 180,110,55 170 lop 29, 25428535p 350135 175 BC173 112 Bc5488 114p6 474F 1.25 6 Wily ' HP214416111 4.75 292484 262 0204-1324 94 EURO 1.60315814 254288 222 2502264.29 81217313 lip BC548C 2.85 Baker 900 CONNECTORS 847(15/114) 99p 252646 550 2N4289 150 25139 3.30 801730 14 13p GLAZE 512 HI VOLT 17P 01,1111.2801 812549 10way 1.40 Mare - 252847 9130 2144290452 314140 1.07 BC 174 210 50,697,15, 02217,08.20111, CERAMIC 308A SLOPING FRONT500mA 2.29 252714 122 31 25429148p 35143 2.85 80174024p 405490 15p 1005F11(1/ 252 5 1 6 . 9+ 99 TOGGLE1510411 woo 1.75 VEROCASES 17p 102 PP31110/1,451 252848 602 2N9292 242 WIRE -000050 64w. A*13 452 35152 3.00 801748 812550 isp 10026 2KV 302 lima, 30V 14) SPST 49p V5 220,1744 600604 252890 1.10 254294452 35153 2.47 80175 752 6055002 612 1001,E 3(5 332 4.30 SPOT 5, Straight2.25 252891 2.28 2 to 3000.230 254287 2.50 35154 2.56 BC177 MP 812551 151, 10966 469 372 OPOT 661, 54w. A+13 V6 1710121x 800m1* 292892 300 254302 398 35200 6.93 801774 250 to3301121p TYPE 14. 9C5574 16p 2200 45 452 5064 OPOT 12.069 791, Angled 2.95 100nwn75nep 2529044 27p 10.40621 2.98 8C17713 26p 5.65 17p 10p Adjusted le, 4 to 7W0 471-1 42969 21(V 39p tp 6 9125578 0.12 .0121/ 2.75 64w Air -13 IA of any HP type 252905 252 2114304 41p 392113 3.35 .SC178 160 912559 to 6193 34 474 818/ Dip REMOTE 17p 101, 14 4.35 4281Mtn., 01 2.40 Above 715.59 2529054 29P 254400 15p 35088 591, 801784242 8125594 14 10 to 11W In 1nF 2KV 395 S0951, CONTROL 1.54 17p 101, 252906 25p biased Wggies in 64w. A + C 254401 27p 40360 60p 801788250 812558016p I1, 3318 372 Ink 610/ 44p 2/1 lip 10p TY- ---99 Ml 100VA stock. (Handheld) BOX 2929064 300 254402302 40361 67p 80179 20P 812559 16p 202 21(4 44p Angled 2.95 3A 17p 101, ,81.79c9,1° .11.10,1 292907 012.0-125 ;less s phone 94,61,22.41n, 25p 25440330p 40362 872 BC 1794 24 812 5596 14 Female 591,A 42 50.9 49p 0.96 White -109 4AH 1925.55 2528076 24 254409 360 40363 196 80179825p 84559017p 3n3 2KV 470 292920 PUSH Purim 31 way 1.75 -70P TYPE P: 3.7 254410 42p 40364 3.25 801790272 90560 34 3,3 41(V 522 - TOROIDALS Non -Latching 2142923 252 LOW NOISEE3 64w. A e 8 ,. 2544161.50 40372 1.80 BC 1132 100.... 812580 162 41(V 572 Up to 500VA tn Push to Make -159 443 (0.'11' 252924 ROTARY POTII 47 Straight2.75 10/1 10p TYPE A: 1-r-5. 264427 792 40373 2.60 8C1824 14 BC5600 24 tonF 2KV 572 stock. - 252925 150 WITH 1/4- 152 64w A +8 10pHP7 IVp to 4 at 254440 12.58 40374 234 801828 13p 40555 45,, - .. PROFESSIONAL1M m25320921°6 - Please Phone Push to Break - (5,85 71 OP. 7255417701 58025p 801821 10p SPINDLES FEEDTRA0' Cap e, Angled 3.25COLLET KNOBS204 -10p418n9 1734 80851 414 2'm 64w A.0 404074040 8C18214 14 90170 i, 115667TO 201 lOP 5006 72 More add - All fit :"spindles 253011 650 254888 99p 40409 BC182LB lip 9c177 igp 34 adequate P&P Straight2.95 1.59 LOG KEY -SWITCH Black Isuff ix 131 1" PLUG 253069 502 2558981 29 40409 1.50 60153 105 KY 72 19p 322 TRIMMERS MINI as transforms's 64w. A FC Grey (Suffix G) FUSES 293053 272 2549011.69 80410 801834115 Bc577 34 As above wd h FR.M IMLALARDI are heavy. 253054 1.80 DP Mains Syntch Angled 3.35 1Snwn Short In Packs of 4 TOI 14C1241,182 54 2549021.85 40411 185 ,.9C1239 122 00478 22p UP TO 100VDC 253055 802 254903 1.96 132 lip ,44,o sp, °PST withdrew . 61508 plain 5622 2810 59i,1051BF4511115 40412 902 01-,21- 80479 asommemoi 253065504 6011 222 As above mere* 180041101 Key in both IDC S1500 plain 58p 59p7018ISC 1091 254904 215 40422 2.95 5C1,331 106 6.60 2, 3 amP 25305514 1.20 254905 2.75 812057 Ino swath,/MP 2p6,. 1026 PRICES PER Posioons Pm 2 CONNECTORS6151E12 -line 64,5 amp 185 4046741.29 19C183L4 13P 9C688 4.90 keys) 599102201117291 43107 425 254906 2.99 40513 175 801831-8 13/, 8121894.10 1070648u 272 METRE 190Pal Male*LetchS1516 + line 64p7 amp 253109 OUSTPROOF Solid Hook-up. 591, 4., 484 2540073.20 40537 960 BC183LC14P 80115 Sip 2pF to 220F - -- 8106910 15mm Standard13 amp 59p -73' 2532321.50 254908 3.15 412184 10p 551102.00 PRESETS 63 1405040, Op FOOTSWITCH 40594 991' 24 Any 80100, 10 way 89p 61506 plain 57p 253250 302 254909 2.90 106117010M 52510 65pF wan metal 40595. 99p 801848'29 80,21 94 16 way 1.29 K1500 plain S711 PANEL 253251 36p 294910 155 40600 BC184C132 1.64. 5.0. 14 (200754ri 382 MAINS) buttons 2.58 BD 124 IMullard/ Mke Horn. 15p SPEAKER SPOT 1.85 20 way 1.45 K151134 -fine 88p FUSEHOLDERS 253439 980 254913. 2.59 40601 2.36 801841- IOP 26 way 1.75 2534+0 60p 254914 2.69 Z28 Sunda/6 Pert um -2.60..,,,3 Twin 1 Amp 148 DPDT 2.75 K1510 - line 66p2Ornos 380Aztec 86414s 253441 An 40602 188 6018418 739 18, Twin 29 Amp - 34 way 1.99 15rmn Winged 254915 2.95 40603 1.09 BC184LC 142 130131 44p ..., pi...n. 15" 36pWaloband 4.50 2534.421.35 206 Standard Hord. 2, 5129.59 lip ROTARY 40 way 2.25 W 1508 742 254916499 40804 1.85 13C186 8013244p Main DP 4 amps 2534428C4 254917 472 406013 244 80187 242 80135 352 14 INat. Pmeponicl 30019 2', Am6 50 way 2.45 W150G 74 cr/ K S 1.86 292 Thurribwhaal or to. with %- vino. 254918652 40631 2.12 80204 60136352 1.10 V PCB Male + Letch 253444 9' Soindle for .47 93 s, 3 Core 6 Anlp 552 21mm Short ill 1AT 1.70 254919 750 40635 1.35 80205 292 80137 37p Lorbn Adiustable 809168 S2108plain695 253445 440 254920 84 54 206 292 80138 37p Standard TyPeS .47 100 a, Prices inspoSt 253446 only 99 , n 10 way 95p 02106 plain 69p 6.09 254921 55p 40643 580 00207 29p 80139 34 OP .47 350 30p 4 ,,,,, 3 A9/0 Stop IFS. P....a.'" in UK. Cheaper 64 1p 1 16 way 1.47 521113...line 75p about types 253447 5.72 254922riNs 40673 702 80208 295 80140380 I 83 llo to 12 way ,, to callers. 253448 31' CERMET 20 20 Way 1.80 8.56 264923992 40822 1.60 40209 29p 80142 2.40 1 100 55p 5211G +line 75532.211,(1.1,9-95, TURN PRESETS 90 Tower Transistor 253512 1.06 254924922 40971 792 SC212 102 (113153 1.25 1 50o 402 SCREENED 2p 2 to 6 way 28 way 1.94 2Irnm Standard ,00K,.5 2,35 293553 2.65 SCig 1000 14p Manual IBIble) 25492695p 40872 74 802124 14 601551.20 2.2 25 82 5'6'6 55p 34 way 2.40 K2108 plain 69p 254927 8122128 14 80,57 swp ABM. 5000. 11I, 2.2 63 9,,, Stereo 272 2005110 2.85 2°P 952 AC126 492 40 way 2.55 0210G Plain 6921.00MHz 2.74 253164 258 2144928 1.59 412128 13C2121. 10p 150159 54 211. 5K. 10K. 2.2 100 112 5" 5.4114 Elektor 30110.5o aN3563 320 lip.. 3p55p 503 way 2.75 tO, K2118 +line 78p41.0085415 2.14waY80212LA253565 207 25495427p AC127 320 14 801803.00 2015,509. WOK, 360 Circuits 6.50 22 30, 51.' 'P..° 1. 4, 4 ,0 3 ,,, a, . Female 1bradwK 211G , line 78p2.009157 2.2 253666 50p 25496525p AC128 34 BC212L8 142 80181 1.75 200K, 5001( 13 25 105 4 Core 4 Screens Texas TTL 725473656687 .v54 25496625p AC132 882 BC213 14 each 89p 3 3 40 110 55p 10 Way 84p 21nun Winged 2.097152Mlit B0182 2.50 4 Cora. Singie466 16 way 1.07 W2108 86p 149 254967 255 AC151 515 BC2134 111, B0183 2.70 3 3 63 14 3.2768MHz 1.49Texas Op 101 253569 50p 254968 24 AC152 BC2138 12g, 801071.0p THERMIST085 47 16 ...,,,,,,,,.., 20 way 1.25 W210G 86p 459 & VORs 4.7 25 4 e54'4" Core 612MP 4.000/1i5 1 49 5,18 293570 5.5p 254969912 412153 552 602,30 132 130201 1.30 * sw,,c,,,,,,,,,, 26 way 1.49 29nun Standard 4.14.4324.08, axes MOS 573 .204501012.75 50213L PLEASE PHONE 0.7 40 '5, 12 Core sop 34 way 1.75 K2908 253571 ACI53K84p 14 802021.39 01.099610 Pease Phone 88p 1.581/18m0r9: 4.95 2535724.95 25501113.85 AC176 2, 8C213L8 135 813204 1.44 4.7 63 14 40 way 1.96 229012 881, 255030 441, S402131-0 14 4.7 100 14, Mike Guitar 4.4336190404z Texas Linear: 253564 2.76 401780 379 80220 1.00 0111=11311 50 way 1.99 253585 2.99 255033 44 AC187 25, 80214 lop 80221 10 25 24 996 4.95 952 CERAMIC 10 40 1,4 Lead - CAPS: 81k, Red, 5.00MHz 1.50 etional 2536329.88 255036 1.60 AC107K 28p 802148122 80223 1.00 DISC/LATE -AERIAL 015 PLUGS Vol.Grn, Grey.80°611' en, 255039 1.90 AC188 252 130214C 132 80224 950 10 63 1.3° nterface: 0410120 -MINI 14 2 PIn 6.9375MHz 3.50 2.95 36,43:1jo;-, 255095 365 AC198K 8C2141. Itkp 1.11 10 100 50011058A 25p 9P Blue. 40P 80232 100V 10 14 3 pm 8.00MHz artional Special 253636 352 255087392 ACY17 a*5* 750 UHF 29p 110 (Please state 149 1s0 80214/413/, 80233 70p TYPICALLY 5% 5 pin 1804 122 15.00018,1.35 unction 2.95 263641 695 255089 370 ACY20 75, 8C214LC 14 80234 22 25 112 75111/40 2114 DIL SOCKETS 74 512 5 pin 240° 165 18.00MHt1.75 National Data 253642 255089370 ACY21 BC37 14 1313237 22 40 Lo. C.)..) 502 74 9160 14 3°°° 4'3' 14 55in Dorm,. 151111,175111 20.001849 253643 265172152 E1C22374162 1°"41°44 7P 22 63 Pins prof W Wp 5P 1.59ConversiOn 302 0CY22 752 1313238 982 16p 54 151917 , dot 8p27.640M0, 1.69 2.95 253644 56, 255175562 8023713lip 8132394 672 22 100 21p NAffilB°W 8 $p252 ,,, ACY28 752 SIEMENS 639 RIBBON 14 19P I 5mm (.. line OP41300MHz1.65 253645 665 255179332 ACY44 980 BC237C190 BD239C 1/40 MONOLITHIC 47 26 142 9 p 352 2p, Toshiba CMOS 280 255180 43P 47 40 .,,,, Priopsper loot 16 102402 30p 21mn, plea, Sp 100.00Pailz 2.95 2.95 25360225364 AD1313 6.75 00238 14 802402 592 MINI CERAMIC '" .,* 2945183 1.00 40149 790 EIC2354tsp. 430240C 732 1177 10063 7.262 la 505 21mrn 4 dot Bp 5'5M1k 140, 22n6 102 810wwaya,2255pp lop -OW CHASSIS Care,. filter 90pHitachi Micro- 2N3563 16e 255184 1.10 802388 161, 1302414 610 20 20 p 211.11T line Sp 40150 2.80 47nF10p - SOCKETS processor 9.00 253702 lop 2551813 1.15 AD161 E1C238C 172 80241c 675 100 18 22 22 p - 2 gp 29mm Met 1311, 39p 644 lip 14 16 way 39p Hitachi Memory 253703 10p 255189 1.00 401132 BC239 15p BD2424 662 100 25 162 24 24 p lop 3,, p Grey only) 39p 1002F lip 1027 8p 253704 255190 INIP - - 40 20 .6Y 48P 28 - -1 IIIMBIEME 7.50253705 lop AF 100 752 BC2394 lip 80242C 702 100 24 284 79 2 5pon 180' 14 top 255191 797 BC23913176 5A55.ER LA,. 100 63 25p- 24 way 62p 40 Hitachi Powerfet AF109 752 80243A 72p 2 Spin 240" 162 Nut Coven ...s, 253706 10. 255193 900 SC239C16p 35 99Pup 8.00 AF1I4 651, 00143C 852 CERAMIC DISC 1°O 4° 3°4 30 way 6pin75pNand209 15rnrn Toots 253707 14 255194 79p 20117 1.00 51C250 222 802446 84 220 10 162 woo 2E80 INSERTION 7 22015 250 152 3282p Pin TEXAS 253708 lop 255195 990 BC2504 232 BC244C 1.00 220 16 14 40 way 885 FORCE DIL 250 Colours as above8pL87Lolodstrorn AF116 892 "UNDER- 253709 lop 295195 99p 44124 727, 13C2508 24,1 1302454 1.14 POLYSTYRENE 220 25 22p SOCKETS DIN LINE 253710 102 255196 1.08 25p 24pin 425 Side Cutters STANDING" 44125 72p 802500 25p 002450 1.30 1801/ 220 00 6 on 253711 102 255209 24 BC251 250 220 40pin 5.25 2555°0(678,0p 14 55Solid State 47126 722 8024641.04 516OR ER -63 302 POINTERS 15rnm -Ls-. . 4.95 253712 2.00 255210252 EIC251A 296 100 40p 41139 40p BD246C 1.50 220 . 102F, 152F, or 21mm L8PuGnipe Nose-. 2N37131.38 255220 150 AF170 BC25113 270 002494 2.00 470 18 22p UHF P1.269 ?rone''' 5" Digital 4.95 0, 22pF, 2721 GRADE ONE. Colouras abovePlier8 5.2" 253714 2E63 255221 2517 BC251C 28p EID249C 2.31 470 25 Car Electronics AF172 88p 332F, 39pF. 214 °LASSPCB spin lop 253715 3.31 265222262 44178 13C252 24 40250.4 2.11 470 40 332 LowTYPES10.35 loss, 8p 852 47pF, 58pF, SINGLE -SIDED 4O5 superior L870. Snipe 5098 2537163.60 255223152 41200 652 002520 232 802500 2.48 470 83 430 178, 24Ornrn g..i., 9140110 PLUGS Security Elec- 25522438p 002520 242 1°44.1644, 470 100 802 500 DIALS 15rnm 46045 4.7- AF201 752 80433 790 1802F. 22021 952 M951 'tonics 4 95 293725 1352 255226 24 AF239 50253 22p 80 634 551, 2°9RedPotrit 265 10.36 . ' 55, 274F. 33/32F. 1000 16 42001952nen .4-0..9 45P Rest' 8ed. 271.43;341 4.86 255226 252 AF240 1.50 80253823p BC1435 812 39,, .53p 1000 25 34 1,35 Yellow.Green, 1000 40 1911;5' Long 255227 lip AF27961.19 BC253C 242 03436 812 4741 6802F, 464 420 x 245rnm R:undesrld. :X Sp y6-oPicinitrit 266pP 293734 1.98 C°°P"'"79.c:ic°tIn9'54.95 1:30 255245 372 AF27901.19 60256 24 60437 616, 1nF. 1.58F 120 1000 83 652 Star skt 40P Clear 1 to 1028P 915246 402 902564 20 80438 200016 402 Computer AL102 3.49 682 1204, 14F 14 -- PHONO CHAS. Clear Taper 285 CII TOOLS .1.955247 45p 401013 4.57 002560216 00439 901, 2200 25 1332 FERRIC 1190 501) SOCKETS Science 4.95 22N93377338522.00.45 60257 4.7r1F 142 080 414" Side ,, 253740 246441, 45110 2.20 200 00440 912 1006 eta. 2200 40 70P CIADINDE 4'00 1.10 5521e 180 DIALS 21mm Cutter 10.02'vn°16.°°1166.6 OM AU/13 3,31 8C2574 210 130441 910 'Ts' 2200 63 1349 PELLETS 2.76 BC258 41.6 La° 14.1 20PRed -1. Point 28pC73 408" Side 4.95z9J 755258 2.138 13C107 1 24 00402 935 470016 750 Ouick dissokring 1,11e110 1.15 Ouad 250 2537662.90 255293 SILVEIMOMICA 811,Point 28pCutter 9.28 253767 98p 13C1074 120 BC258.4252 60529 1.20 1% 470025 890 Enough to make 3.19 255294 1.20 801070 1302588 24 80530 COAX ITV) Grey * Point 28pC72 45" PlierS 253771 1.75 1222n 1.30 PLEASE PHONE BATTERY 295295 1.97 Bc 109 , 0 p BC259 252 BD535 752 Rada bY All Metal Clear 1to 1028p(Snipe I 253772 1,83 CONNECTORS 7.62 295296 1.26 Bc log,1, 13C25913 260 1605 752 Massus611.4 ETCH RESIST 25p PP3 Snaps 152 Clear Taper 28p 54x 54.. 253773 1.99 POLYESTER .99 255298 1.37 BC259C27p . 80572 996 V Socket 901088 14 C2111) uFd PEN 252 DE.soLDEFue403 C240 115941 293773 3.20 BC280 30p 10 PP9 Snaps 122255302 8C108C 142 80538 SOp TYPE I5 16 4 Ont. SP.. 114 551 400 Box for 4HP7 STANDARD PUMP 4.49Motorola 2.67 2515303 3.90 00 109 lop EIC26013 322 BD539 80p 250V 22 10 Op Nibl 914 272 00250125W) 253773 RCA 255305 296 22 KNOBS 81 100. High 8C1090 14 902990 396 005390 1.10 1021 1500. 18 7p CANNON TYPE Box for 6067 4.99 2.75 25530637p 00261 33p 80540 AUDIO PLUGS 1411 for 9 " Suction 13C109C 1, 1N1P 22nF, 33nF. ETCH RESIST Iron Stand 1.65 253773 25530740p 6122614 3451 005400 1.20 47 16 Bp 13 PIN XLRI 32° spindleal Anodised 4.55 BC 113 396 441. TRANSFERS Box for 46011 Elements Thomson 2.75 155306250 BC114 lap 13C213113 34 80675 74 100 10 1 Male 1.70 104F , Op Thin lines 332 Grub Screen Spare Teflon (Slate Iron) 2.05 2143779 1.70 255354 190 BC2610 302 BC 115 296 95875 772 1500. 200AF if° 16 100 2.Thick lines 6...1. 156 Fitting Nose 85p C240806 2153789 3.21 00262 312 410677 782 220 10 112 545355 1911 00118 34 10p 1 Thin bends Sockets TRANSISTOR Black Plastic No. 216291111 255359730 001164 002624 32p 001378 832 220 16 122 141;:ssisl 253790 2.73 370 3301F. 470nF A Thick bends SOCKETS ' 41.25 9 metalIIIZEIMME 64 253791 2.47 ...255166 25p 00117 .,,, BC262B 33p 00711 1.32 i, 470 10 17P 6 DIL pads 1.50 1011310C 109) No. 3 Med.) 652 nsert - 34p 253792 2.6E1 4.5487255 EIC1113 195 002620 34p 00712 1.32 470 16 104 6. Female 2.35 No 61Microl -.- 680nF 14 Transistor ,An,390512. 33mrn e BTC601 LCD .253794 252 255401 35p 00119 sep ut..163 301, 80)(141.30 IpF 22; 100010 mos 1-051- . -. 952 2143819 255415 1.10 SC26361 1000 18 metal insert 39p Push Button 252 BC121 42p 31p 8D)(181.59 1.50 392 24 7 DotsrPoles JACK PLUGS 35P 0525002554 253820 352 255415 1.54 Kw 0, 00263C 321, 02532 3.47 2. 5.2 99p 2200 10 348 8.0. I" edge 2 amps AC/DC, #6. &pp.. 03121430551 3 No. 5014.111 253821 1.84 255447 165 130125 37, 80264 405 82054 1.70 2200 10 442 con,,,,or. Q.,r6mm + metal forquant1ty 1KV DC 650 253822 90p 255446 195 00132 390 6122648 422 20455 1.76 SIEMENS 3300 10 602 9 5A,i0pre -.. -- "nserf & skirt 750v AC So 51 (Med.) 253823 452 25544921P 130266 352 801581.80 3300 10 64 of Please ph.. 80134 36 POLY.0 sheer ,- m,op (KEYNECTOR( 39pFully guaranteed 652 253824 1.70 255450 232 130135 44 002664 393 B13457 5.25 5%250V 7.616111 Sc. 52 Age.) 4,00 10 H59 anove 36p 4." 544 3pp flaw Win, mew.M4. As 043 34.50 253826 782 255451 251, 00136 451, SC2669 370 804586.15 1 9 $afety Block 1nF, 125. 2n2 PHOTO 6- Metal bomb.ro 66p 293827 782 255457292 80137 390 50 300 412 001801.60 43, 427,48 72 C7.95 253854 44, 25545829P BC 136 64 BC 301 440 90161 2.80 CAN SENSMVE PCS M4.° 3°P - 1 to 10 39p MINI TESTER SOLDER 125gms 8n2, 10n, 12n, 1st Class Epoxy 2Y,.mm Mono 253855 30p 25545929p 430140 29, OC 302 432 80182 2.34 15n, 14. 22n, ELECTROLYTICS M5. As M3 but Pocket Size 18swg 2.95 255480 722 2,, 3,, 36,. Glass. For better 122 IEC MAINS 2538554404 gc 141 3, BC303 472 800923.75 4700pF 40V 2.50 r.,4 th., 2Y, mm Metal 30mrn 42p2000 OPV 22swg 3.10 253856 45, 255461 64 BC 142 25p 00304 462, BF115 355 470001 63V 3.50 5 KMP 3PIN 47n ii, spraying Expose M6. As M4 but Anal09 253058 312 255482 408082 130143 306 -00307 14 81119 1.00 56, on. 53. 10.0:70,F Isiv M.P. 24 4149 N.Y., OOPUrnin tau,/ 31`)..54.1. Chassis Skt. 44Meter S551111111.111112538584 372 255484 BC147 ,4 .8C3076 lip 84121 799 103n, 1502 15p Di* «dad 14 1585 34 7. Pointer 24p UK's Greatest 253859431. 295485290 BC147A 100 8C20713 155 60123 702 7ANTALIUM 100, 1801.55 3', mm 5144,,, Line S1,1. Retail Variety. 43550 312 00127153 SIEMENS 22,1338867674 .2256555444991 11113563: I ICC 30314 . 11304 BEAD/2455 100a 2201.90 362 Ping 130, 16mm SOLID Superior 20,000 3902. Bc8C50 ,11:4877C5 200 39°Pno POLY -C 8030613 142 .. 0 1 35V '142 103. 114 1.66 3'd mm k.a.,k, Chassis Plug ALUMINIUM OPV 1000y top°" BF154 24 9%1099 1' °M- 149 233 x 220 'Molest listed doe to 255496 1.59 80148412p 80309 14 8F157 585 .221355 199 51°n° 202 50P MATCHING AC/DC, 5 AD C' 2145543 12.00 100, 124. .33/35014o I,4.0.°.I. 253902 133 8014801, 803094 14 BF160 260 150, 110 04604 H444 - KNOBS 2. 5.4 AC. 0.10 to ono,. 253903 .,,,, 255551-- 37p 803098 60150 552 .47/35V 13 AMP 80148C 132 180n, 224. lip 100.160 166 .44,4 SOCKETS ME1. 15mm 255 452 041/356142 100x220 2.15 DOMESTIC00111E871C 4131,691 16.80 Only 5,05My 253904 14 5c149 top 8C309C 14 4160 55P 270n ,1..2,. Chassis 255854 352 152 1.0/35V 14 203, 114 2.21 d.,_ M9. 24mns58D device. sold 253905 14 9121498 14 51161 514 ,Mono .F04.50P - 6800 20,000 193 4 ...... 2 M 10. 30mm 25918 33p 253906 132 255756 HOP 130149C 14 BC3,5 15P SOP 33°4' 1'''''"'''''' 2.2:169 233, 220 4.55 25p ,,,,,, 2.2135V 14 Developer tor ' 1 ' Stara daptor 2 way OPV 1000v DC. 25929 360 253924 8.30 255813 230 80152 35, BC320 25p 60100 674 880n 1.95 26p 34 3 3/350 1112 above (do not 2". inn, Mono --'"2000v AC. 0.10 259294 459 253945 8 255884 5.95 BC153 232 6,187 295 4701,leF1104.1 34 4,2,16., 56415p 202BC321 sop use Sodium i ael.ng skt 82p1111111=1.11 tO 106A 32.00 25930 24 253962 396 3%mm Mono 259306 302 2143964 1.42 2te 5985 585 a Cg c 1 i r 2171; BCEI C 3322; 114'9 9F06117703 3: 8008 4.7/356 206 0148841 256027 30P 6.8,25V20p 500m1 NEWSZEI 251131 240 254030 755 - 1301574 12s BC337 162 01,1 74 77p 250 225,0060330 .5..050 ,,,,- POLYESTER "4MIEMIESE 72:11710372 4265: 22,544003321 8699 601576 .050343387 210% 6,8F ;77.7 2,06; In, 1n5, 2n2, 6.8/54 21pLine''/,"Mono 201, . 20mmSlow Fast BC158 10p 383.47. 608...... lb ALUMINIUM 100,.A DIL REED 251303 55p 254036 ,84 2146082 11.99 24,594, 8C350 24 61179 10135510 'A " Metal 40P CASES 256099 1.20 5,1500 350 101 MI= °I:Pons/A(1NoornromiallY 251304 602 254037 it BC382 35? 8F180 389 ''''. 4E801304RD 1A " Ste.) 19p 15p 159. 22n. 15'16V 222 301. Gpw,44 .95 Th2306 64 254058 21461011.30 BC3821. 30p BF181 15125V 32o O.+ COPPER '4 "Stet° Metal 10, 256109 1.15 5C159 lip 302 33n lip p.m..--- ,, 5, 3999 199 251308 66, 254059 175 2N61, 901594 14 .130.383,3 94__,_ 60102 34 470, 64, "2216.31/ 24 CLAD 505 8cratchproof 1 "9 "959 3802 +Diode 2N1711 352 254060 122 6F1/33 302 100n 142 22/16229, 2.5 43.7 830 316 mm Mono 3, 15mA 254061 101, 258121572 6,-.59e56,95 ..14.36 Bc364 33% 12/154 asp 33/100 34 2.55 isp81 6a4S, al %" & Screen 2.95 2911859 9°0 256122 592 150n, 220n tip 99p 171,10p 251890 502 254062 10p -13C160 -'''' 803641 30p 8F185 34 a304 3* 47/8.3V 3132 2.35500,A 1.99 42P 3.75 x 3.75 ggp 3, mm Mono 125 5300 251893 411.3 254064 1.15 256123. 652 2c10, up 80407 242 13F1134 14 1100 2 8a542"2.75 1.99 2146124 592 602 ' 3.75x 5 1.14 lip 105249 2k0 252060 7.14. 254069 1.00 rs, 00408 242 951195 125 256125 64 e12187 1- 54186 470824 120

22 ETI AUGUST 1983 Miiiiwi. 03' 41 a. ,I,oTl 1 1i t Elr., !!!!!!!!IMInalM!!!!7!!!!!!!Olimi!!!!!!!!!!!!!!MMTHMV,,IkEM!! ER 12;;;; ,tli'lluteluellke!!! iglefilliiefife!!! .,_1,,. 1 ,.7 gra . 1118gglli.,a i 4 ..i,---!..,4 . Ti vra** 45 *44°F0_ c.. ' V ri .. 13, mil 1434Egiv011agtfgliiiiiiiiiaMmAdliiiiii11111RIEURRIN2222;PaiiiiiMEgliffilliihilg Ilatl] . - '' --iiii§141*,400 144MTWOkil P-(,) 2.501t7A1clEiel> 121;1g;0 faiReff,MIllef!PMinitntiliallitiVI*Inca",tagi6MrfiMfe 04:1311H,19113.3MP'Mkrqgi m mm fi-i SZSMSSSZg82 -i,-i.1,,-ir,i,sir !LIMEMirRe!!!.. 3 ; t ME"-"."'73"4"Hnr"qUEIll3 ' ,4.... -,.. . 03 Way 2f, . ,...., --,-- .,.,ri.., Efihlra5diff.hig NMANHUNgaanniiiiltaniiiiiMilinMaaitnittlin ei.,.....,4.,....f.4...4441Aitosi.::4., 'filitnifigi as g02 iiil.s8e,0,0 0 .=u,,... oo_ E. Ee_wit- 9 E. sig&ettattesce -i. ..,i,. ultligsmcc418/0211148SRMSVUSPCMASIS88 gaRRAWWWWARS8SAIIMSUSRUSESSMSA,5ggPgeSS2SR8SWASCR nY - -"SG22:$1:=NIA8--"' " :::1-7.:22nAgVggg -,., , 0-Nmv. -.i.'4- - ,ts . -sggissi...... 0 -tr:, 3 2,..s° ;4 14.0"1'c : 0:0 aca 0 . _. .41w) 15= illir.: gfL: =.E - i,Iy.,1,1.AariaiiiMai patugsasne"g2gmgragPsraWinEEE.s..,..&44,10144swiaaamtmwswalactegmtuRAwillinittiPaftlifeaaatettitilisiliaatinaltilitilabelliltiltingeOl!!!!!lia.1144tWitin 88sg2nAgv:pgnssimia---"'"' .VIV*'VI"'"*"'VVVW'VVV:VV"*"VVV.WWWV$W r.,,,,,,.. .,,,,,,,...., 9ng gg VWVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVW .. , mentimia151;511 SMN? (& ,,-.'.,z 32 mgg .E cii-EE-c, ®- .2.5 M 12:'03.1, E E mmmamEmaamaailEmusimame==!!!Taln!!!!!!!!!!=!!!!!!!nBRIMMI5gillitillEMHERMIRIMIll ,gg,gg .. g,ggggg , ...... , ,, -'--- ciCzr) (..)7:6 amoi>05e ..o 0 8 tg, .8 c.- 00). .te g g0 ....s- ,.. 2 8 - """ailtuarnamum"*"."2ailitigPm2iVIRMOUMMantiamiattattileri!!0MitifsniniMigmstmlitmencicatil Ci) sio'Zi:fi1d;Etat'IS.-2 60 ;11152-"tire:1 () '534 00 -Oa i 2COti : 8 "'...Y-51!!!!!!!!eala,!!!!!!a't!Ei!!:!HMahMnF4:'!!!!!!!!!!!,!:!!!!!!!!!!!!!!!!!!!!!!!!!!TMEMEtEW9Min!!!!!!!TM!!!!!:!HiV,MIPT77;nr',42nPlAgn:IMPINHIMMFgtilCW=T4,;;;;:4,z;gggggggggggggggggggg;;szgggg,1ggg,1,1g,1:4 '44::4S7,21=284;4132822ggnalM,7, 0 allgalt2E1um 8(7) IfiEg! cli ,3 A == 0 ...,gBEtn:4E: 2 -53.04;00812.madawAg82,9a02809.,9,908.7288H2011§§§EWMBElaiiEiginailk___,,,, ------':::.::::::;;;;:::::::iii3312338RagRFF6H44000PRRRESESRRSSRERRRSgE§W§pggV.115mymkwa4iiilli ReganWHHi""Wilw..xq ----- ,,,,, ------, ,,, ,, ------,,, -- -.... -.. 0- _ o. ,Tle!!!!MUMM41!!!UMM!!!!HETrMTR!!!,q!!!MMIMil!fan7=155!!eFiM!!!!!!!!!!!!!!!!!!!!!!!!!!!1!!!!!!!!!!!!!!!!!!!!! ChCi-I CncoacE% gi E a=: "E" 82 ". ,..0 - . cc2 i. 4grvz 0 ...... 3m3.33.333;..3....mmlyymnymmilvilirpromiRmigAvslmmaAggiwalismaffi§§§2PPPI,'14.40-hPitanUARM.Pg,9114 MR101106,5,F7,15magEggathialtionvapilinWhOTOTTAraPPEHE ,,,, ., 84,-.'7'g E: t L° 4-25: Lo.0 cl; !!!!;1!!!!!0!!!!!!!!!!!!!MinEWI!!!!!!!1!!!!eaal!!!!ii!!!MEMIIMINT!!!!e:1!!19!!!!!!!!P!!!!!i!!!!!n4193Winfiffecin!! Z i. ,..,...... c ,c- ... 274,,,Ar.gr-m-,22111,744°-MitsdkAnk'j6666n666z=16z56666z5666665z5666=5,16666,gggg,,xxgxm2gggguggxgggggggmgggg,u,;----,72-RRgA....gA.,,mm-::2,92SRRgiigg,97,;;;;A,E,77,gMagImm,, A.,,,,,,,,,,mA A,,,,RA,,,,U,,,:ggRP,,AA,,,9- ""!uuu-2222h88A19R-A,-...U'UAT-aaa ,, 11:7-7-2222222"22223n.nn?AnnnnnnnnFAIInnnW,33H3n3"222n3W gifugg6gKifH4-gNA.PgiVr.f:F§Halkidb,4igiV§Hfini"Miil CC Li4j w S g) :1 0 c3 ...9 .'2 2 ; .. 6R6 . 63-. Of ce2 °' . - ,e66 W aaa f66 RIR z .iaaa ^^..,.,c.inito4rioi"., N.,,.. ..:^rioi 0(.) N O E il n.e Eri- E a:6'a ... 0' 0 .c'le Ee '42,, !elli . ,..,_,,,,.>3>igg' ----1 .N:11,g,,,,,, cv 1§71;-, ca,mt 1#44,1tn1:ir -- g W.,ar.-.; --;"" r--A.9.4... mtislii.: ;41p o..>. N 22.0.gbb '' .C.315.86 W',14,,,,as.611 id gro,- ilhe,gmlszoelemmagmmegegrarag4,!antenmingri.sr .,..,z;;gFp.maggsg'%,..-8,T,Img.7-arl 1!!!4!!!EM;Pa;;!°147IggEgi2:. _ o .2 Um: i 4; 41,,g, ..>i ..,- gge, a.,9,93.9. 3a o>- SAA suAiiiiliiiiiin's;na.gaggsaagq22 , ,, Vii,T!!!!!!!36 ..mlIII z 0 0.0 0-z..- , 0 Eai .. 0 la %...4.4 14:14.422 t ilsgg ns !! > in ! !.] ! :.$' a N w e --- a.,...-.4 iJaaalaiataaaa ,,,;g!i!!!t!!! ,; 1r: .c g = `.1 ii WU eau H! ..._.! r2 2 5:1 ,.- LLJ °c1)2 q r. ce 0 u To-4' c .= ..c .c utt lam af- , H!! 32'244' !,91 N8 ';it 8§ .EApg Vigg tat gg ggggg r,gggg °1"gg UM, ;4 8.0.?2,9-1 - 2 §5 :1', q ii 2 -.,-; ,..A § pi 0i.4 , o §8 Iiiiig-'2MVA ,'.2- 1-1 °.--IT< 4 'Er.-li 0 1. 1i .:1146'15ttig0 C 2 -g34,-.4a-gg- ''InU,,agg. .aLU'''°'-',I1.Hglim t2A.....721;78"s-% ----.40 &m."11.2 t. .. `' 'F1'z'z ".2.2'''3 .,,,,,,AAELME.. ..;:, ,5gH §§ a o2 * g 4E; iri'.. , '8.`PaP-!ALMO - g 727R iitti tfaCj=0. (" tOCP - 418 r1;`;gi : """'"'" "'" " " ..,.. !! O0..... 01- g>:uj © .1 cclogn 0- al! e 412 4 gi3 : 3 :2 M6131.4gfilifffHilfiataliffitti..-,r., . - g 8 - ,.. , 4 1 z.2.1 § M170, ii F, 2 I Fl ,W, §Nnaa?, fre° mj, pasmurismsmap;n*sitaasalagspawigemig&tinis,plwaseampagpommmengitin4wqqataigui..i.,,,,..,., 4 . . , ,, 7 - ...."." -- --.^". ,,,, ,..--- ..--,..,....: 'I h § hi IE 24 Ri i i ." I, a It imi Iiii azz,QvA?FillginkiiMrMoi§4 ;;AT6'52Pg=grap--"Rv23slaganz-AzioisuraF47,±3riaLcraw,g,$61§ El. E0 0 3 Ch ('D E t '.t. t g li fit) CC a F-'1-Fi''''FiligRUUMI7I'a'a-U'Ulg'4U".a .°1&12zz..i..z.....n.zzL..1,-AgggggggggiFiiiiMiliiiiiiiiiiEEE-E-EZEZ,F,i;MLL5V/88gg888%- lad 0 4 ° 8 1 -2 ir- r 8 = 3 e '"d .. oC'''.45. ES " e 0. 0.0 -,:,-Ai8'4 ,,,:-.;:;;;;;!,71::::;::,Miill;t1P;WICI! 112'88°888 ..- --r%oo_-_,..--. .,-!Nnt2,82"m7IM944222gn2--;88n,;=. amaatattaatellaMilateePRICIMMHIAIIIIIPIn!iaittilanni!maimH7thleffREMM!..1 %,..0, . uxill0 ,. 0 10-38erDca I '' / = At t - . Is E8 Err° 1.5 5 i .0 88 111111iiiiiiiiiiiii3iniiiintrinittltHiiii,Ta§0§.4007,2?m"HEEEzzai±:iltmiP.ovAnggnagimiiiRgm'gRPARFoFEF6101PAHMEA!.:Hflinrhugili.,,,,,,,,,,ERNIKAI m'imStS221-21-Vittiltztz2a222z12m121'8888886:66 '''' "''''' 68664 ...- ,,,,, . ,,,,, ,,, ...... -.-,.-,-.....-,- ...... 0CC 51E1.5?IA eill .1 E§ 1 r-vsoro -48IS !f- i omg ' VilahiarNagYa017721'""rithfinghllagialligniii=1:::iiiiiiii-3igHANNIAMatiahrigiiiiiiiiirniiiiiheif_tWMI,ifliEeV,LttfafgaaIUUAMnfidfii,SVM6V,T9MMMfittHWRWtnfUeMilr:!!,MTMEH!HtaqCWCMMUtqft4Mn42 ii: 1"''-4'"'N''''NNN,2" f;i;NNgGN°2..9-A"-"'S'""'-"'15V"iRgiMThM8 84Enn" 8=.40- Rig:"§§MliiiiWg.NT THE MOTOCAR Could this fairly ordinary looking Lancia car be the Car Of The Future? Motorola certainly think so. Read on and see if you agree.

At a press conference recently, Motorola revealed Thirdly, by using electronic control, the engine's per- their Motocar (who says ETI has a monopoly on formance can be much improved. Fuel efficiency is very bad puns?).It'sa LanciaDelta withalotof important in Europe, but over in the States, tough anti- electronics where there used to be switches and yards and pollution legislation has led to emphasis on emmission yards of copper wire. control. It was, in fact, this legislation that provoked the in- Even though they were very nice to us, impressing the terest in electronic engine control in the first place - who presswasn'tMotorola'sreasonforspendingthe says that conservation is always bad for industry? equivalent of several Rolls Royces on building the car. Finally, an electronic control system can offer driver Their main targets are the car and car component and servicing facilities very much more easily than the manufacturers. Not only are Motorola trying to persuade conventional system; for example, fault finding and fault them that they need to bring car electrics up to date, but monitoring can be automated. that they should use Motorola products to do this; and fur- ther, that they should work closely with Motorola to get Why The Rush? the products they need. So, the car itself is by no means a Motorola are keen to get into the market as soon as finished design, it's a try out for a large number of different possible. They reckon that by 1987, 7% of the European ideas. semiconductor market will be for cars. Naturally, they're expecting a certain amount of competition, but they hope Why Go Electronic? that their early start will catch their competitors napping. Conventionally -wired cars have been around for quite a while now, so why should anyone want to change? Well, from the manufacturers' point of view, there are a number of good reasons. Firstly, and always firstlyin manufacturing, there's cost. At present, a wiring loom for a car costs around f35. Motorola's electronic system, with a great host of addi- tional features that we'll be looking at in a moment, would cost around £100 to build after a tidy up of the prototype. Obviously, Motorola learned a few things during the building, and some newer components better suited to the project have since come on the market, so with a little op- timisation, the cost could probably be halved to f50. However, once you start to use specially made com- ponents, a lot more cost saving can be carried out, and the price would easily go below that of the conventional loom, especially if the price of copper rises. And the elec- tronic system will almost certainly be a lot easier to install. Secondly, there's reliability. Well designed electronics should always be much more reliable than electro- This is what the Motocar no longer has -a conventional (messy) mechanics. An electronicloom would considerably wiring loom containing about 500 metresof wire. reduce the number of connectors in the system. Not only would this improve the car's reliability after sale, it would Take A Bus also cut down on manufacturing costs. Did you know that At the heart of Motorla's electronics is a four -wire around 40% of all cars straight off the production line re- multiplexed bus. This links the master control unit to a quire some remedial work to be done on their electrical number of outstations that are responsible for controlling systems?

24 ETI AUGUST 1983 FEATURE

reduction in supply voltage (for instance, while the battery is turning over the engine on the starter motor). Surprising though this may seem, it is apparently cheaper to do this than to use P -channel FETs. Each load switching unit has an A -to -D converter on board, so that it can measure, for example, the output from the petrol tank gauge. It also has a load -state monitor that can sense blown bulbs. This informationisall transmitted back along the bus to the central control. Further development of the load switching unit will almost certainly involve Motorola's smart power device, soon to enter production. These devices have a T-MOS power transistor with logic and drive components on the same chip (together with, perhaps, a DC to DC converter). The layout of the main bus and the fibre -optic bus: the fibre optic These may make it feasible to use single load switching bus radiates out from where you'd expect the gearshift to be. The units, with each load on the bus having its own dedicated main bus is in a H -shape and is drawn with a solid white line. switching unit. In order to avoid increasing the number of and monitoring the car's functions. The master control has connections by using these units, they may well be housed a separate interface with the controls on the steering col- within the controlled load itself. umn, and there is also a completely separate fibre optic system that controls some 'luxury' items. Condition Monitoring The four wires of the bus have the following functions: Hard at work just gathering and transmitting data is power (positive, negative return through chasis), signal the vehicle condition monitor, one of the four other types earth, data, and bus control. Data transmission is sequen- of outstation. It sits inside the engine compartment and tial and bidirectional inhalf duplex mode with auto - monitorsfluidlevelsandotherinformationtobe clocking and RZ. The control line is used to sort out which presented to the driver. A single A -to -D is used to monitor unit is sending what to where. The power line is for the the alternator output, and, as well as being used to provide controlleddevices as well as fortheoutstations the system's equivalent of an ignition warning light, this themselves, so it has to be fairly meaty. All the other con- also determines the control of the battery charging. ductors can be light weight. The other three outstations are semi -autonomous in that they are not under direct central control: for instance, Outstations you could not have the engine control unit having to deal Alltheoutstationsarebased on the Motorola with an interrupt when it was just about to fire a spark MC6805P2 microprocessor, as is the master control unit. plug. Besides the engine control unit, there are the cruise Motorola now say that they would now use the cheaper control, so that you can take your foot off the accelerator and more appropriate MC6804P2, but it was not available and the car will maintain a steady (and legal) speed, and when the design work was done. the climate control, a posh phrase for an air conditioner The simplest of the outstations are the load -switching control unit. units, of which there are six, all identical. Each is capable The engine control has a pressure transducer in the in- of switching eight loads of up to 10 A, although in the pre- let manifold; it also measures the position of the distributor sent car, the most that is used in any one unit is seven arm in 0.35° increments (by using a phase locked loop to (some units switch rather fewer). Because N -channel multiply up the output from a position sensor). Thus it can devices are cheaper to make than P -channel ones, N - control the spark and fuel injection timing to a resolution channel T-MOS FETs are used to switch between the of 0.35°; it can also control the amount of fuel injected. ground connection to the controlled devices and the car However, the opening and closing of the inlet and outlet chasis; this means that the controlled load is always at valves is still done mechanically. positive supply potential with respect to the chasis, and this could lead to a corrosion problem. Alternative Bus Motorola's proposed solution is to use an on -board To avoid running lots of wires from the controls DC to DC converter to provide a higher voltage supply of mounted on the steering column, Motorola engineered a 30 V. This will allow the N -channel FETs to switch reliably much more simple multiplexed bus to link the steering col- at the standard supply voltage (nominal 12 V) in common umn to the central control unit. It's a three wire bus, with drain mode, even when the system is suffering from a unidirectional data flow; the encoding is done with stan- dard CMOS, rather than a microprocessor (shame!). Gone is the familiar needle and dial speedo - it's replaced by a flourescent digital display, as in the latest Maestro. The display itself is an off the shelf Futaba plasma display,drivenby (you've guessedit)adedicated microprocessor, this time an MC6801. To be fair, the micro is kept busy displaying a range of messages (in a choice of several languages and imperial or metric units) on two separate LCD displays to tell the driver about the state of the car, distance travelled, etc. For instance, it is this that will tell you if one of bulbs has blown. One interesting feature is the use of an EEPROM to store the odometer reading. When the ignition is turned off, power is held on long enough to allow the old reading to be erased and the new one written into the EEPROM. Motorola's smart power device - to be used for future load Motorola have put quite a lot of though into developing switching stations. systemthat is assecure as possible,toprevent ETI AUGUST 1983 25 FEATURE : Motocar

vicing and repair easier - but only provided that the garage buys a special adapter! This special unitwould, when plugged into the car, take control of the bus and run the car through a test sequence, with a readout that tells the mechanic what needs attention. The special adaptor units should be around the size of a largish pocket calculator and cost about £150 (a special one will be need- ed for each car type). Shine A Light The other multiplex system uses optical fibres to con- trol seat positioning servos, windows, door lockingand The Futaba display used, in ful action. Unfortunately, you can't see window mirror positioning. This system is entirely separate that the figures are in a rather reasuring green, and the main beam from the other bus system, and it has its own control unit; indicator is in a baby blue ... it's also arranged in a different way, as a star network. Each unscrupulous dealers from being able to wind back the unit has its own line running back to the control unit:this reading. was necessary because of the lackof T -junctions for op- Multiperplexed? tical fibres. Motorola claim that rather than confusing the poor Motorola's optical fibre system is unusual in two ways. mechanic, the multiplexed bus system should make ser- Firstly, the same devices are used as transmitters and receivers, thus allowing two-way transmission along a single fibre. Because only short transmission distances are involved, signal strength is not a problem and a- relatively inefficient detector can be tolerated. Secondly, visible light is used because this will make it easier for a "mechanic" (perhaps Motorola had better in- vent a new term for this person while they're atit) to detect if a signal is present. The cost of the components needed for a visible light system is also considerably lower than those for an infra -red system. Motorola say that fibre optic systems are used because they offer higher noise immunity and lower weight than copper wire systems. However, thefact that they've been confined to the luxury features of the car is probably evidence problem - orisitjust my cynicism? Parting Shot One last system that we haven't mentioned yet is the radio. It too (yes!) uses a dedicated microprocessor, and even though it's a Grundig radio, themicro is a Motorla MC6220. It's worth reflecting that Motorola started outby making carradios;havingpartially surrendered that market and gone on to greener pastures, they're now set to invade the rest of the car. ETI

Above: one nice touch not mentioned so far is that Motorola have tackled the problem of supply line transients at source, the alternator, by replacing three out of nine of the diodes with transient suppression types.

The present test unit (right) is just a little bigger than a hand-held calculator (though this does depend on how big your hands are .. .) Apparently the production model would need little more than a (yes, another) microprocessor, some ROM (possibly on board the micro) and a display.

26 ETI AUGUST 1983 'WY IMFNIX 1T-VP' moSEE am r Cp LLIN LB ELECTRONICS , volousSOS g t g g a MMIL Nit. Al ...dn LIMITED STOCKS MI Peem Alen Man III Brand new havard H452, power supply and Nickel charger, Ri mai = LI- 4Ulan 146Taa output 13 volts at 0.7A (max 1 amp) 7" x 3" x 31/2" appx. Fully OW1 -1 1411 I cased and boxed only £4.95p pip £1.70p. ALL MODELS ON DISPLAY SPECIAL OFFERS (while stocks last) TEST EQUIPMENT CENTRESOPEN SIX DAYS A WEEK Mullard .2" Red L.E.D.'s 0.06p, 7805 38p, 7805KC 5 Volt 1.5A 75p, RETAIL MAIL ORDER EXPORT INDUSTRIAL EDUCATIONAL 78H05 5V 3 AMP £3.50p, 5K 3/4" multiturn trim pots 14 for DIGITAL MULTIMETERS (UK C/P Free) £2.50p Aa 3'ff DISC DRIVE BONANZA OM/t3OM en Piedr MUSS' PERTEC FD650 DSDD £199 + VAT SMIED TEAC FD -55F 1/2 Height DSDD 80 track £228 + VAT NAND HELD With free carry case B eckman T110 As T100 plus Cont. test. Cannon 2/3 drive SSDD Shugart Compatable £129 + VAT KI125C13 range 0.2A DC 2 meg ohm £24.95 etc. £67.85 40 Track K D30518 range I OA DC. 2 meg ohm £29.95 SIfam 2200B 21 range 2A AC/DC K IXIOC26 range IA AC/DC 20 meg ohm £34.95 20 meg ohm E39.95 Apple controller card for two drives £40.00 + VAT p&p 50p 11055C28 range 10A AC/DC 20 meg ohm £39.95+Optional carry case £2.95 60104 28 range 10A AC/DC 20 meg ohm £34.40 B ENCH MODELS ASC1 1 coded qwerty KeybOard ,manufactured by Alphanumeric TM353 27 range LCD 2A AC/DC £86.25 £19.95p p&p 70304 As 1010 but 0.1% basic. £41.30 (Woking UK). Model 60K brand new plus data K D61516 range10A DC.2 meg plus Hfe testerE39.95TM355. 29 range LED 10A AC/DC £86.25 TM351 29 range LCD 10A AC/DC £1.50 189M 30 range 10A AC/DC. 20 meg plus Ale £113.85 tester £69.95Optional carry case £6.84 25 WAY 'D' Types, plugs £1.85, sockets £1.85 (solder tail) p&p 2001 28 range LCD 10A AC/DC plus 5 range ND30 16 range 0.2A AC/DC 2 meg ohm £41.95 Cap. Mater with cast £108.00 30p. Telephone for bulk prices. ND30/B As above plus conL buzzer £44.50 TM451 41/2 digit LCD every (unity 10.02%1 £171.00 H031 22 range 10 AC/DC 2 meg ohms plus cont. 8" Drive Cabinets complete with power supply (LINEAR) to take 1503a 4/, digit LCD every facility (0.05%) boner £58.95 £171.00 two 8" Drives, Brand New £99.95p + VAT (carriage cost) 1503Na 0.03% basic version of above £189.00 Twin 5" Cabinets with power supply £30.00 + VAT (providing a DM2350 21 range 10A AC/DC 20 meg ohm 1504 true RMS version £201.25 miniature hand held auto range £49.95 Slfam 250024 range LCD 2A AC/DC 299.95 disc drive is purchased from us,if drives purchased elsewhere B eckman T10034 range 10A AC/DC Matrix (ITT) profaning' 31/241/2 digit £40.00 + VAT) 20 meg ohm E56.35 DMAYs standard & true. RMS 4 models stocked 9" Green Phosphor Monitors Brand New and Cased Composite £77.00 - £201.25 Video Input 18n\hz band width £78 + VAT each (carriage cost) FREQUENCY COUNTERS SIGNAL GENERATORS (220/240v AC) Textool 24 dil Zif Skt (used) £3.95p p&p 30p Brand New 13" Colour monitor fully cased. Full warranty 540 x 236 pixel. RGB TTL Inputplus apple Input £220 + VAT FUNCTION : All sine/square/ (carriage at cost). triangle/TTL. etc 16100 1 HZ - 100 KHZ 290.00 BNC Lead Bonanza coax lead with BNC plug at one end, 2 metres T61020.2 HZ -2 MHZ £188.75 plus £1.00 p&p 30p and 10 metres plus £2.50 p&p 75p PFM20011 MHZ hand held pocket 8 digit LED £77.60PULSE American 6110A 8 digit LED bench 2 ranges 100 MHZ £77.00 16105 Various facilities 5 HZ -5 MHZ £97.75 86108 9 digit LED ketch 2 ranges 600 MHZ £113.85 Express AUDIO: Multiband Sine/Sguare 80008 9 digit 1E03 ranges 1 GHZ £178.00 TF040 8 digit LC040 MHZ £126.50 LA627 10 Hz to I MHz £96.85 LB ELECTRONICS TF200 8 digit LCD 200 MHZ £166.75 A6202A 2011z to 200 KHz 'List £94.501 £83.50 11 HERCIES ROAD, HILLINGDON, Optional carry case £6.84 RF Prescalers - Extended range ol most counters 56402 100 KHz to 30 MHz )list L79.501 £89.50 M UB1 0 9 LS, ENGLAND TP600800 MHZ £43.00 L5917100 KHz to 150 MHz £79.35 TEL: UXBRIDGE 55399 TP1000 I GHZ £74.00 OSCILLOSCOPES ELECTRONIC INSULATION TESTER IF 501 500 V/0100m with carry case £83.00

MULTIMETERS (UK C/P 65p) H PA102Z 20K/V 10A DC 22 range & cont. buzzer £13.50 Full specification any model on request. SAE by post. 1111102Z 20 K/V 'NM' Series NAMES: THANDAW ELECTRO 22 range & cent buzzer £14.95 'CS' TRIO: '3' CROTECN 'or Noon ETC5000/5001 21 ranges. 50K/V. SINGLE TRACE UK C/P £3.00 Range doubler. 10A DC. £18.95 3030 15 MHZ 51ey. 95min tubs plus component TMK50023 ranges 30K/V. 12A DC plus tester C/P C3.00 ' £177.10 FIRST FOR NASCOM 3 cont. buzzer. £24.75 SC110As Miniature la MHZ battery portable NH56R 20K/V. 22 range pocket £10.95 Post free £171.00 HM103 15 MHZ 2mV. 6 x 7 display plus ETU 102 14 range 2K/V pocket £6.50 component tester C/P £3.00 £181.70 830A 26 range 30K/V. 10A AC/DC overload .Optional carry case £6.84AC adaptor £6.69 protection. etc. £23.95 Nicads £12.50 DUAL TRACE (UK C/P £4.00) 360TR 23 range 100K/V. Large scale D T 520 Duel 20 MHZ £241.50 10A AC/DC plus Me £39.95 HM203/4 Dual 20 MHZ plus component AT1020 18 range 20K/V. Deluxe plus life tester £287.50 taster £18.95 C31562A Dual 10 MHz (Lint £321.001 natal) TN 36011119 range 20K/V plus Hle tester£15.95 3131 Dual 15 MHZ component tester £278.00 Metric Professional multimeters C51566A Dual 20 MHZ All facilities thist £401.351 In stock 3 models from 9E34 .50 £74.75 NM204 Dual 20 MHZ plus component tester VARIABLE POWER sweep delay. £419.75 CS1820 Dual 20 MHz with extra facilities SUPPLIESIUK C/P £1.001 Dist 008301 £485.00 fre,anX*vtgIS Ws XX Ot PP241 0/12/24V. 0/1A. 0X710 Metric dual 15 MHZ + component tester £35.00 E304.75 X,` OPTIONAL PROBE KITS PP243 3 amp version £59.95 X 1: E7.95 - XID E10.50 510 £9.45 X100 216.95 PS 13078 8/15117 amp twin meter £24.95 HIGH VOLTAGE METER DIGITAL THERMOMETER Direct reading 0/ 40 NV. TH301 LCD -50°C to 450° with 20K/Volt.DIK C/P 65p1123.004141111111 thermocouple £88.43 DIGITAL CAPACITANCE Highlyrecommendedforitsversatility,thislatestNascom micropro- AC CLAMPMETER cessor can be the foundation of a superb professionally styled system of excitingly METER useful applications and development ... and of course, Electrovalue are accredited x1`300 0/3004: 0/800 0.1 pi to 2000 odd LCD 8 ranges Nascom suppliers, ready to deliver your Nascom 3 (and ancillaries) NOW! VAC. 0/1 Kohm 9 ranges 4:11-Paj 0M6013 E52.75 ICarry case C2.951 Nascom 3 Microprocessor £549 + V.A.T. With carry case106 C/P 65p) SE8.50 (to drive monitor or TV set) LOGIC PROBES TRANSISTOR TESTER Monitor for above £120 + VAT. Direct reading PNP: NPN, etc. Nascom Dual Disc Drive SS/DD £685 + V.A.T. I LP10 10 MHZ 128.50 TC1 £21.65 (takes standard 51/41 DLP50 50 MHZ with carry IUK C/P Nig £945 + V.A.T. case and accessorles1152.33 Nascom High Capacity Dual Drive 1D Nascom 2 in kit form inc. keyboard but less power supply, case and SENDSENe/G LEALARGE RAM. Always available. £225 + VAT. SAE UK 20 DID YOU KNOW that foralmost 20 years Electrovalue have been foremost suppliers AUDIO ELECTROnICS i_,bzste of components, etc, costing from pennies to hundreds of pounds? So why not send 301 EDGWARE ROAD. LONDON W2 1BN. TEL:01-724 3564 for our new Summer Price List and see why it pays to buy from us. ALSO AT HENRYS RADIO. Or. by Peel aft CMIGUES/ACCEW MA or you eon IslexPone your wan 404/406 EDGWARE ROAD. LONDON. W2. TEL: 01-724 0323 Al oxlers ikopMelocl Mil. a Oxr. ELECTROVALUE LTD. carsx*Ited. Head office, Mall Order and Shop: 28 St Judas Road, Englefleld Green, HENRY'S COMPONENT SHOP. TEL: 01-723 1000 Egham, Surrey TW20 OHB. Egham (STD 0784: London 87) 33603: Telex 284475. North -personal shoppers only. 680 Burnage Lane, Burnage, Manchester M19 1NA (061.432 4945). EV Computing Shop, 700 Burnage Lane, Manchester (061.431 4866). Electrovalue and EV Computing Shop are members of the Microvalue group.

ETI AUGUST 1983 27 Modular Amplifiers the third generation

Due to continous improvements in components and design I LP now launch the largest and most advanced generation of modules ever.

WE'RE INSTRUMENTAL IN MAKING A LOT OF POWER In keeping with I LP's tradition of entirely self-contained modules featuring, integral heatsinks, no external components and only 5 connections required, the range has been optimized for efficiency, flexibility, reliability, easy usage, outstanding performance, value for money. With over 10 years experience in audio amplifier technology I LP are recognised as world leaders.

BIPOLAR MODULES MOSFET MODULES Module Output Load DISTORTION Supply Size WT'Price Module Output Load DISTORTION Supply Size WT Price Number Power Impedance T.H.D. I.M.D. Voltage mm gm Mc. Number Power Impedance T.H.D. I.M.D. Voltage TT Urns inc. v,, n Typ at 6040 Typ VAT Watts n. Typ at 60Hz/ TYP VAT rms 1104: 7KHz 4.1 ITS 1614, 7101: 4:1 4.8 ± 45 120 x 78 x 40 420£30.41 i i Y-.10 15 4-8 0.015% <0.006% 1 18 76 x 68 x 40 240 £8.40 MOS 128 60 <0.005% <0.006% IO 30 4-8 0.015% <0.006% ± 25 76 x 68 x 40 240 C9.55 MOS 248 120 4-8 <0.005% <0.006% 1 55 120 x 78 /3 BO 850£39.86 11511060 30 3 30 4-8 0015% <0.006% ± 25 120 x 78 x 40 420C18.69 MOS 364 180 4 <0.005% <0.006% 1 55 120 x 78 x 1001025845.54 /15124 60 4 0.01% <0.006% i 26 120 x 78 x 40 410£20.75 Protection:Able to cope with complex loads without the need for very special 1l0 12B Id) 8 0.01% <0.006% ± 35. 120 x 78 x 40 410£20.75 promo ion circuitry (fuses will suffice). 45244 120 4 0.01% <0.006% ± 35 120 x 78 x50 520£25.47 , Rise time: 3ps. S/N ratio: 100db 115248 120 0.01% <0.006% ± 50 120 x 78 x 50 520£25.47 Slew rate: 20v/p 8 Frequency response 1-3d13): 1511z - 100KHz. Input sensitivity: 600mV rms 45.164 180 4 0.01% <0.006% 1 45 120 a 78 x 1001030£38.41 Input impedance: 100K I/Damping factor: 10034z >400. t i 53(i8 180 8 0.01% <0.006% 160 120 x 78 x 1001030£38.41 Protection Full load line. Slew Rate 15v/ps. Risetime- Ses. S/N ratio: 100db. 'NEW to ILP' In Car Entertainments Frequency response -340) 154-- 50611z. Input sensitivity: 500rnV rms. Input Impedance' 1001(11 . Damping factor: 100H,>400. C15 Mono Power Booster Amplifier to increase the output of your existing car radio or cassette player to a nominal 15 watts rms. PRE.AMP SYSTEMS Very easy to use. Module Module Functions Current Price inn. Number Required VAT Robust construction. £9.14 (inc. VAT) 1156 Mono pre amp Mic/Mag. Cartridge/Tuner/Taper lOrnA £7.60 Mounts anywhere in car. Aux i- Vot/Bassareble Automatic switch on. II5fiti 20mA [14.32 Stereo pre ampMm/Mag. Car fridge/Tuner/Tape/ Output power maximum 22w peak into 4IL Aux u Vol/Bass/Treble/Balance Frequency response 1-3d131 15Hz to 30KHLT.1-1.0. 0.1% at 10w 1614, 20mA £15.36 HT 73 310110 pre aim,Two Guitar (Bass Lead/ and Mic SIN ratio (DIN AUDIO) 80d8. Load Impedance 311 separate Volume Bass Treble 4 Mix Input Sensitivity and impedance (selectable) 700rnV rms into 16K fl 3V rms into 811. 11578 Stereo pre ampAs 4566 less tone controls 20mA £14.20 Size 95 x 48 x 50mm. Weight 256 gms. Most pre -amp modules can be driven by the PSU driving the main power amp. A separate PSU 30 H available purely for pm amp modules if required for C1615 £5.47 line. VATI. Pre -amp and mixing modules in 18 different variations. Stereo version of C15. £17.19 (inc. VAT) Please send for details. Size 95 x 40 x 80. Weight 410 qns. Mounting Boards Fe, ease of construction we recommend the B6 for modules HY6-HY13 E1.05 line. VATI and the 866 for modules HY66-HY78 E1.29 (inc. VAT). POWER SUPPLY UNITS (Incorporattng our awn toroidal transformers) Model For Use With Price inc. Model For Use With Pries inc. Model For Use With Price inc. Number VAT Number VAT Number VAT C17.07 PSU 7202 x 45248 £22.54 PSU 21 X I or 2 Hy30 C11.93 PSU 520 2 x 45124 PSU 41 X 1 or 2 HY60, 1x H56060, 1x HV124 E13,83 PSU 530 2 x MOS128 £17.86 PSU 73X1 x'15364 E72.54 £17.86 PSU 74X1 x 45368 124.20 PSU 420 1 0 HY128 £15.90 PSU 54X 1 x H5248 PSU 55X 1 a MOS248 £19.52 Pal 75X2 x M05248, 1x MOS368 32.1.20 PSU 49X 1 x MOS128 £16.70 PSU 51 X2x HY128, 1x H5244 £17.07 PSU 71X 2 x HY244 £21.75

Please note X in part no. indicates primary voltage Please insert "0" in place of X for 110V, "1" in place of X for 220V, and "2" in place of X for 240V.

28 ETI AUGUST 1983 WITH A LOT OF

HELPFROMCDELECTRONICS111- IIFI LTD

PROFESSIONAL 11141 THAT EVERY ENTHUSIAST CAN HANDLE... Unicase 1 6., Over the years I LP has been aware of the need for a complete I V packaging system for it's products, it has now developed a

r1 --4.- k'-'4,0 IV------,,, lif unique system which meets all the requirements for ease of ,10 assembly, adaptability, ruggedness, modern styling and above -1i'l '' 40011110, all price. l* Each Unicase kit contains all the hardware required down to the last nut and bolt to build a complete unit without the need for any special tools. Because of I LP's modular approach, "open plan" construction is used and final assembly of the unit parts forms a compact aesthetic unit. By this method construction can be achieved in under two hours with little experience of electronic wiring and mechanical assembly. Hi Fi Separates UC1 PRE AMP UNIT: Incorporates the HY78 to provide a "no frills", low distortion, (<0.01%), stereo control unit, providing inputs for magnetic cartridge, tuner, and tape/ monitor facilities. This unit provides the heart of the hi fi system and can be used in conjunction with any of the UP Unicase series of power amps. For ultimate hum rejection the UC1 draws its power from the power amp unit. POWER AMPS: The UP series feature a clean line front panel incorporating on/off switch and concealed indicator. They are designed to compliment the style of the UC1 pre -amp. Performance for each unit which includes the appropriate power supply, is as specified on the facing page.

TO ORDER USING OUR FREEPOST FACILITY Fill in the coupon as shown, or write details on a separate sheet of paper, Power Slaves quoting the name and date of this journal. By sending your order to our Our power slaves, which have numerous uses i.e. address as shown at the bottom of the page opposite, with FREEPOST instrument, discotheque, sound reinforcement, feature in clearly shown on the envelope, you need not stamp it. We pay postage for addition to the hi fi series, front panel input jack, level you. Cheques and money orders must be crossed and made payable to I.L.P. Electronics Ltd. if sending cash, it must be by registered post. To pay C.O.D. control, and a carrying handle. Providing the smallest, please add £1 to TOTAL value of order. lowest cost, slave on the market in this format. PAYMENT MAY BE MADE BY ACCESS OR BARCLAYCARD IF REQUIRED UNICASES Price inc. HIFI Separates VAT Post to: 1LP Electronics Ltd., Freepost 4, UC1 Preamp £29.95 Graham Bell House, Roper Close, Bipolar HiFi Canterbury CT2 7EP, Kent, England. UPtX 30 + 30W/4 -8n. Stereo £54.95 Telephone: (02271 54778. UP2X 60W/411 Bipolar Mono HiFi £54.95 Technical: 10227164723. UP3X 60W/81.1 Bipolar Mono HiFi £54.95 ELECTRONICS LTO Telex: 965780. UP4X 120W/411 Bipolar Mono HiFi £74.95 UP5X 120W/811 Bipolar Mono HiFi £74.95 Please send me the following UP6X 60W/4-811 MOS Mono HiFi £64.95 UP7X 120W/4-811 MOS Mono HiFi £84.95 Total purchase price Power Slaves I enclose ChegueD Postal Orders0 Int. Money OrderEl US1 X 60W/411 Bipolar Power Slave £59.95 US2X 120W/4 11. Bipolar Power Slave £79.95 Please debit my Access/Barclaycard No. US3 X 60W/4-811 MOS Power Slave £69.96 Name

US4 X 120W/4-811 MOS Power Slave . £89.95 Address Please note X in part number denotes mains voltage. Please insert '0, in place of X for 110V, '1: in place of X for 220V (Europe), and '2' in place of X for 240V (U.K.) All units except UC1 incorporate our own toroidal transformers. Signature 101 ETI AUGUST 1983 j29 TV STORAGE SCOPE

The Tele-Scope 200S is data and display the stored data. In buffer, which can be varied to a storage oscilloscope which manual trigger mode, the incoming produce a shift in the position of utilises a number of electronic signal controls the changeover of the display. techniques to convert signals into a the two memories, so if the input The resultant analogue signal is form suitable for display on a signal only occurs once, or is fed to the analogue -to -digital flash television screen. The unit is removed, the last signal is displayed converter which produces a six -bit designed around the latest on the screen. When measuring DC word for each sample. The sample technology in analogue -to -digital levels, the auto trigger mode is used rate can be up to 10 MHz (one conversion, using the Ferranti to give a continuous trigger, as the sample every 100 nS), and is ZN441 flash converter to convert DC level has no recognisable selected using the front panel switch the input signal to a six -bit binary transitions for the circuit to begin marked 'width' in the same way word at a point in time, which is operation. that a conventional scope has a determined by the sample rate. This time base selector. The six -bit word sample rate can be selected to be Functional Description will appear on the data bus and the up to 10 million samples per second The analogue input is taken via input address clock, which is (or one sample producing one word the input coaxial socket to a running at the sample rate, writes every 100 nS). switchable attenuator and is the data in to the selected memory. The resulting words are stored buffered with a source -coupled FET. When both the memory cycle in one of two memories, which take A second FET in the source of this and frame scan are completed, the it in turns to store the incoming buffer puts a DC offset on the memory is switched to read and the

are

erVb ) SELECTED C 4 -ERBIUM IN C IC20 Q. p C. 0 4

13 -WAY Cr-l-/-) erN.T"`! JUMPER C 0 4 a C 0 4 a 4 ICI 0 C IC14I 4 ) 4 0 4 I C ) FREI:111E6C OUT C ) 4 .1

IC11 CD, C

4 016 015 014 013 612 011 0 10 C

1C12 TO RV1 C 1C13

0 - FROM SIN2

NOTE C14-24 WERE OMIT Ito FROM THE CIRCUIT DIAGRAM, THEY ARE FOR SUPPLY LINE SUPRESSION. Fig.1 The overlay for the logic board (circuit diagram given last month). V TO TO TO 30 LED1 RV2 S.63 ETI AUGUST 1983 TRIG LEVEL PROJECT

We conclude our description of this innovative piece of test gear with the circuit of the data processing board and full construc- tional details. Design and development by Ian Gooderson.

25H, TO TRIGGER SELECT. SW3 PARTS LIST - LOGIC BOARD

Resistors(all1W, 5% except where stated) R1 560k 2% R2 270k 2% R3 180k 2% a R4 56k 2%

SIN 2 R5 27k 2% R6 18k 2% Q R7 5k6 2% R8, 9 2k7 2% R10, 15 10k R11 220R SELECTED R12 FREQUENCY R13 470k R14, 25 47R R16, 17 330R

R18, 19 270R R20 4k7 13 WAY JUMPER R21, 23 1k0 TO LOGIC BOARD R22 56k Fig. 2 Overlay for the front panel PCB, containing the input attenuator. R24 470R Potentiometers output address counter is routed to small PCB on the reverse, which RV1,2 10k linear holds some of the components this memory for the output Capacitors(allceramic except where sequence to begin. The output associated with the input and trigger controls and the corresponding stated) address counter is cycled at 5 MHz C1,8-10,16- and the six -bit words are output to a input sockets. The power supply 24 100nF comparator, which compares the board is mounted in the rear of the C2 100pF case, with the transformer tothe left C3, 5 20pF word to the video line number. If (viewed from the front). C4 120pF the six -bit word and the line C6 68pF First build the data storage and number are equal, the comparator C7 10pF outputs a data bit to the video routing board (the circuitry for this C11 27pF board is described in this month's C12, 13 2n2 summing amplifier. C14,15 22uF 16 V PCB This data is then mixed with the article). All the components are electrolytic line and frame sync pulses and mounted on the circuit board (see Semiconductors the overlay in Fig. 5). All the IC1 74L504 output to the UHF modulator. The IC2, 6, 11 74LS74 display has a memory map which is connections to this board are made via a 16 -way jumper lead to the 1C3 741510 247 pixels wide by 64 pixels high; IC4 74L500 each pixel is 200 nS wide and four control logic board (whose circuitry IC5, 7-10 741S90 was described last month).All the IC12 74LS03 lines high, utilising a screen area of IC13-16, 19 74L593 49.4 nS wide and 256 lines high. ICs used are LS TTL series, with the exception of the memories and the IC17 74L5123 This data is repeated on the second ZN441. Although this latter chip is IC18 741373 field of the interlaced TV scan to 1C20 74LS08 prevent any flashing on the display, not static -sensitive, great care Q1-3 2N3819 Q4 BC107 even at high input frequencies. should be taken when handling it because it is the single most costly D1, 2 1N4148 The memories are addressed by LED1 red LED two counters and during the input item in the equipment. For this cycle the input address counter is reason it should be mounted in a Miscellaneous 24 -pin IC socket. SW1 SPDT slide switch running at the same rate as the SW2 9 -way PCB -mounting Next, build the control rotary switch A -to -D, storing each data bit in a logic/input buffer board. All the separate serial memory location. SW3 2 -pole, 3 -way slide switch chips on this board are LS TTL, with (only one half used) The output address counter is for SW4 12 -way PCB -mounting running at a constant 5 MHz as the no special handling problems them or any of the other discrete rotary switch display time is constant. XTAL1 10 MHz components used. A 16 -way jumper PCBs (seeBuylines); UHF modulator lead connects this board to the data type UM 1111E36; ribbon cable; sloping Construction front case (see Buylines); screened cable The Tele-Scope contains two processing PCB. A 13 -way length of ribbon cable should also be for input; PCB pillars; power supply double -sided, plated -through hole board (see Buylines). circuit boards, one for the data connected at the other end of the storage and routing, one for the PCB at this point in the control logic and analogue input proceedings, for later connection to buffering. The case cover has a the sampling frequency selector 31 Eli AUGUST 1983 +5V 0 R8 47R R1.6 ALL 22k 10 11 16 12 6 3 INPUT (15)0 23 18 5 7 7 R7 100R IC1 17 10 IC6 9 21 12 11 4 16 14 13 --5V O I C2 22u 811 //t/ +5 6111 T, C1.1. /7777 2 3 4 5 6 7 IC7 10 9 12 11 14 13 +5V +51/

18 18 1 18 1010 0 +5V IC15 WE. 1(W IC16 IC17 WE 9 4 9 4 U) (1) 51 C8 6 12 +5V ,477 +5V IC9a 1)16 20 14 18 CLOCK 113/0---4-10 CLK 13 4 16 IC2 12 14 15 11 12 IC11 9

13 7 /77 17 5 17 3

/1777 +5V ?p, ,s2t._

18 +5V 16 4 14 116 2 12 10 14 11 IC12 9 2 13 7 CLK 12 .15 5 INPUT 3 RESET (2)0 0

FRAME PULSE 17) 0 MIEN (3) 0 M2EN 112)0 +5V - +5V 20 14 18 OUTPUT 2 13 4 16 CLOCK (410 IC4 12 14 15 11 12 11 IC13 9 13 7 15 5 17

!1777 T +51914T 18 16 +5V 14 16 12 10 14 11 IC14 9 OUTPUT 13 13 7 COUNT 19)0 15 5 RST IC5 12 2 17 3

1177

+5V 3 14 4 5 IC10 6 12 LINE 11 COUNT CLOCK (1)0

32 ETI AUGUST 1983 PROJECT: Tele-Scope

Fig. 3 Circuit diagram of the data storage and routing board. 16 3 4 5 6 10 IC19 9 12 11 HOW IT WORKS 14 13 IC1 is the ZN441 A -to -D converter. This converts the analogue input signal into a six -bit binary word at rates up to 10 +5V million samples a second. The six -bit nil 16 word from each sample is then passed to 10 the memory buffers IC6 and 1C7. If IC6 4 12 0 DATA OUT (6) and IC20 are selected, then data is writ- 6 13 10 IC20 9 15 ten to the memory block IC15, 16. In 12 9 IC23 this case IC19 and 1C7 are in the high im- 14 13 11 pedance output mode, and 1C20 enables 14 data from the second memory block, 8 IC17, 18, to be read to the comparator -018 +5V 10 IC23,24.The memory andbuffer WE IC18 8 enables also select the address buffers, +5V 10 routing the input addressing to IC15, 16, Lb 116 and the output addressing to IC17, 18 in this example. In other words, in this

10 phase of the operation IC11 is allowing 12 the synchronous counters IC2 and IC3, 9 1C24 which are acting as an eight -bit address 11 counter, to cycle IC15, 16 synchronously with the sample rate, while IC14is allowing the output address counter 1C4, 5 to address IC17, 18. 1C12, 13 are disabled to block the respective un- wanted address lines. On the alternate +5V +5V phase, ICs 11 and 14 would be disabled, 2 ?14 0 ICs 12 and 13 would be enabled, and the IC9d5 3 14 two memory blocks IC15, 16 and 1C17, 41 IC25 0 LINE COUNT 76 RST (10) 18 would receive the opposite sets of ad- dress signals. The output of IC8 goes low 6 /7777 when the input address cycle is com- +5V +5V pleted, while the output of 1C10 goes 16 low when the output address cycle is complete. 2 2 IC21 IC22 IC21, 22 form the 256 -line counter, which is advanced every four video lines for a total of 64 steps. This six -bit output 10 1 is compared with the six -bit output from the memory by IC23, 24, and when these are equal, a data bit is output to the video summing circuit. The output of IC25 goes low when a count of 256 is completed. When the input cycleis complete (the input memory block is full), the in- put clock is disabled. The output clock is O INPUT ADD only enabled for 256 lines of the scan FULL (5) and is therefore disabled during the first IC9e and last lines of the display and the O OUTPUT ADD 13 FULL 111) frame flyback time. When the input ad- dress is completed and the frame scan is completed, the memories are switched over and the new data is output to the comparator. The video data is therefore NOTE. refreshed every 50 mS unless the incom- C1 IS ZN441 ing data cycle is longer. C2-5 ARE 74LS161 C6,7 ARE 74L0367 The power supply unit has regulated C8,10,25 ARE 74LS30 + 5 V and -5 V rails at 650 mA and C9 IS 74LSO4 160 mA respectively, with a separate C11-14 ARE 74LS244 C15-18 ARE 2114 5V8 supply for the UHF modulator. C19,20 ARE 74LS368 C23,24 ARE 74LS85 BRACKETED NUMBERS ON INPUTS AND OUTPUTS REFER TO POSITIONS ON JUMPER LEAD Oops A couple of errors crept into the first part: IC6a pin 3 is connected to IC7 pin 12, etc, and not as shown; the supply line decoupling capacitors were not shown, and they are C15 +5V0 0 +5V (22u tant) and C16-24 (100n ceramic) on the +5 V line and C16 (22u tan° on the -5 V +11 line. Additionally, R14 has now been C3 C4 C5' C61C71111C8 C9 C10 22uT 100T 100T 100T 100T 100110071- 100nT ommitted. (Note that all the above 0 OV component numbering refers to the logic 0 V 0 board circuit diagram, published last month).

ETI AUGUST 1983 33 switch (see the overlay in Fig. 1). Incidentally, Q4 was incorrectly identified on the circuit diagram last INSERT FIXING month - itis actually a BC107. SCREWS The power supply is mounted on a single -sided PCB and is supplied ready -built with the kit. The front panel switches are also PCB - mounted as described earlier (see Figs. 2 and 6). With the boards completed, the Fig. 4 This is how you attach the front panel to the box to make it easier to do the data processing board can be interconnecting connected to the control logic

O

OkW0WWAAJN,

4 !I I° to ;1111-1p0 0 .( Pa I911t1i fold,,,,le!rr t' I fi 0.. )Tni WWAWWWWAA

U wovwpwarlYwy

U U Ucr, of V VW fJ

0 0 0 0 0 0 0 0

Fig. 5 Overlay of the data storage board

34 ETI AUGUST1983

U PROJECT: Tele-Scope

THE ZN441 TheZN441 is anultra -high-speed parallel (flash) A -to -D converter com- prising an array of 64 strobed com- parators and encoding logic. A reference voltage applied across a tapped resistor chain defines 63 quantisation levels plus overrange and underrange, one input of each comparator being connected to the resistor string, while the other inputs are commoned and -connectedtothe analogue input. When an analogue in- putisapplied,allthe comparators whose reference voltage is less than the analogue input will change state, ieif the input voltage is Vitxf . n/64 then n comparators will have tripped. The com- parator outputs are decoded into a (the 13 -way ribbon cable) between 1 -of -64 format by NOR gates and then the switch PCB and the control re -encoded into binary by a high-speed logic PCB. ROM. board using the 16 -way jumper. The Two or four ZN441s can be stacked to give a seven- or eight -bit converter data processing board is then Operation witha minimum ofexternal com- mounted on the base of the case First switch on your television ponents.Applicationsincludehigh- with adhesive pillars, and the logic and tune in the Tele-Scope signal speed data acquisition, video an radar board is mounted on top of it, again on an unused channel select data conversion, digital signal storage using adhesive pillars. These special button. Set the trigger switch to and image processing. pillars are supplied with the kit and auto and locate the trace (a white are required becausethere isn't line) using the position control. Set enough space between tracks on the voltage control to 10 V full PARTS LIST - either PCB to allow for fixing holes screen and the full screen width DATA BOARD to be drilled. The power supply is control (the time base) to 80 Hz fitted to the rear of the case, with FSW. On touching the input socket Resistors (all 1W, 5%) the supply leads being soldered to with your finger, a 50 Hz sine wave R1-6 2k2 the upper PCB. Don't forget to drill will be displayed (due to mains R7 100R the case pick-up). access holes in the rear of Capacitors for the mains lead and UHF TV By switching to manual trigger C1, 2 22uF 16 V PCB cable first, though! and adjusting the trigger level, it is electrolytic Now mount the controls on the possible to remove your finger and C3-9 100nF ceramic keep the sine wave display on the lid of the case. The lid should be Semicondddudors screwed face down in the open screen. This feature of the Tele- IC1 ZN441 position, using one pair of holes Scope allows you to do some IC2-5, 21, 22 74LS161 only, in order to make the front interesting experiments - for IC6, 7 74LS367 panel wiring easier. Figure 4 makes instance, you can examine the EMF IC8, 10, 2574LS30 IC9 74LSO4 this clear. induced in a coil when a bar IC11-14 74LS244 First the input lines should be magnet is dropped through it. IC15-18 2114 connected to the AC/DC input Try using the Tele-Scope as a 1C19, 20 74LS368 switch with C1 mounted directly sampling scope on repetitive IC23, 24 74LS85 across the switch terminals.Next waveforms above'250 kHz (not Miscellaneous wire the trigger switch (see Fig. 6) calibrated, but it works). You can PCB (see Buylines); 24 pin IC socket for and the trigger LED, and finally even capture one-shot events up to IC1. connect the frequency selectorlead 250 kHz. ETI BUYLINES Hawk Electronics Test Equipment supp- ly a full kit of parts for this project. All PCBs, the case(drilled and screen - printed), the ZN441 and all the other components are included, together with a comprehensive manual. The kit price is £89. The 'Tele-Scope' is also available built and tested for £109. The manual may bepurchased separately for £1.50 (no VAT required) refunded on the subsequent purchase of a kit or finished circuit. Fig. 6 Wiring the back of the front Prices exclude 15% VAT, and postage panel. and packing is £2.95 extra. The case, A - to -D converter, and the PCBs may all be purchased separately. Hawk Electronic Test Equipment, Unit 1, Park Wood Industrial Estate, Bircholt Road, Maidstone, Kent. Telephone: 0622 686811.

35 ETI AUGUST 1983 01.1M 01010 MI" "OM

1,

M." SO,"

V : ... :

AMO

IAM .00, SPECIALIST ELECTRONIC COMPONENT DISTRIBUTORS 325 EDGWARE ROAD, LONDON W2 1 BN Tel: 01-723-4242Tlx: 295441 CRIMSON ELEKTRIK JOIN THE PROFESSIONALS No Modules Price No 2580 CE 608 40W Mono Price 18.26 WE ALSO STOCK 2615 Complete Pre -Amp Kit CK1010 £80.00 2581 CE1004 100W 4Mono 21.30 ALL THE POWER 2616Cotriplete 40W Stereo Amp Kit CK1040 £105.00 2582 CE1008 100W 8 Mono 23.90 2583 SUPPLIES TO DRIVE 2616a Complete 80W Stereo Amp Kit CK1080 £116.00 CE1704 170W 4 Mono 30.43 2584 CE1708 170 W 8 Mono THESE MODULES 2617 Complete 100W Stereo Amp Kit CK1 100 £131.00 30.43 2618 Add on Moving Coil Kit 2585 CE3004 300W 4Mono MC12K £21.74 42.60 PS. THESE KITS AND 2619 Pre -Amp Power Supply Kit PSK £17.39 2585a MODULES ARE TS70 70° Thermal Switch FE 908 90W FET. Mono 25.65 2585b EXCLUSIVE OF VAT HS50 50mm Heatsink FE1704 170W FET Mono 33.48 2585c BD1 Bridge Unit for Modules HS100 100mm Heatsink 7.13 14.95 150mm Heatsink 2608 CPR 1X Pre -Amp Module 41.70 PLEASE NOTE ALL CRIMSON MODULES ARE GUARANTEED FOR 2 YEARS.

VELLEMAN KITS Some are easy some are hard No Description Price K610 Mono UU using LEDS. 10.05 WE STOCK A WIDE No K1798 Stereo UU using LEDS 18.77 11.16 K1874 RANGE OF BOXES K2543 Transistor Ignition Running Light Kit 14.95 K2555 45.40 K2571 TO HOUSE THESE Digital Freq Counter for Receivers Light Computer with EPROM 36.23 K2566 3 Channel Coloured Light Organ 19.19 K2569 Three Tone Chime KITS IN. FROM 8.57 K2572 Universal Stereo Pre -Amplifier 6.56 K2575 Microprocessor Doorbell 25 tunes 15.53 VERY SMALL TO VERY LARGE K2574 Universal 4 Digit U/D counter with memory 44.72 K2544 Complex Sound Generator 10.26 19" MAXIMUM K2577 Electric Motor Speed Control 11.17 K2032 Digital Panel Meter 16.61 7.45 K2557 K2579 Universal Start/Stop Timer Digital Thermometer 26.57 81.45 K2545 PS. ALL KITS K2583 Heating Controller 50Hz Crystal Time Base 12.00 K1682 61.72 K615 INCLUDE VAT Microprocessor Universal Timer (no case) High Precision Stopwatch 50.29 K2580 Electronic Power Switch Dimmer 12.37 Description Price K2551 Central Alarm Unit 15.48 TELETEXT KIT

This unit will make your TV fully remote control (infra -red) and bring you closerto the amazing worldof teletext. The kit can also be updated to incorporate full Prestel, and with a keyboard this can give you full message facilities for ordering foods or sending and receiving messages (E.G)Booking your Holidays! With a microcomputer as an alternative keyboard the world is even greater adding bulk updating personal computer. to viewdata computers an receiving telesoftware for implementation to any Even without the Prestel option, Telesoftware from the Teletext pages free! The full features of Teletext, including subtitles are all included in the basic kit. An attractive stylish case is available to complement the finished kit Basic Teletext Kit (no box) £130 + VAT P/P £2.50 with box £144.95 + VAT P/P £3.00 box by itself £14.95 + VAT P/P 75p

PR ESTEL ADAPTOR ANTEX ORYX %tool.° A Prestel micro computeradaptorto givefull autodialingmicrocomputer. toyour. Soldering Irons Iso-tip Cordless Iron 31-90+ All the usual Prestel facilities are added via this unit, plus many more, and, can XS25 25W 5.46+ Miniature low voltage operate to any viewdata computer. CX 17W 5.30+ soldering station 13.95+ You can shop from home, bank transmitt messages and receive software, C "iron" 15W 5.20+ Oryx50 50W temp controlled 15.50 which means that the uses your micro can be put to are limitless. ' CCN "ceramic" 15W 5.00+ Oryx super 30 5.90+ The unit is not restricted to just the UK,forat least 28 countries use the Prestel Wide range of bits and elements in Allirons are 240V mains.Earth viewdata format, so you can also mail-order from anywhere. The Prestel unit is stock now. Leakage current is less than 3 ua. suitable for most micro computers even the ZX-81,so at the push of a button, the Soldering iron stand 2.40 The temperature controlled iron can technology of tomorrow is in your home today. We stock multicore solder for normal be controlled within ± 2% tempera- use or fine. ture range from 200°C to 400°C. COMPONENTS-EDGE CONNECTORS BOOKS Device Price ZX81 E.G. 2.98 Z80A 3.20 Spectrum E.C. 3.78 *New Books Z80A PIO 3.20 VIC 20 E.G. 3.78 Please Note. Books are VAT exempt but add £1.00 to cover P/P Z80A CTC 3.20 50 Way E.C. 3.30 6800 6.50 18 Way E.G. 2.80 6810 3.00 64 Way E.C.Plug 2.50 The 9900 Family Data Book 10.00 6821 4.25 64 Way E.G. Socket 4.80 The Opto-Electronics Data Book 4.00 6502CPU 7.50 31 Way E. C. Plug 2.00 The Bipolar Microcomputer Databook 4.50 2114(200ns) 1.80 31 Way E. C. Socket 2.10 The Interface Circuits Data Book 7.00 2708 3.00 The TTL Data Book 8.50 2716 3.20 We stock a very wide range of MDS Memory Data Book 3.95 2732 7.50 opto-devices, from Infra -Red, to The Linear Control Circuits Data Book 4.00 2532 3.50 LED's to Opto-Couplers. The Voltage Regulator Data Book 4.50 2764 (200ns) 11.00 Check us out for competitive The Power -semiconductor Data Book 9.00 ADC0816 (8 bit) 14.90 prices and helpful service. *TTI Data Book Volume I 9.00 *TTI Data Book Volume II 8.00 We also stock 74 series 74LS, C mos, transistors, capacitors, resis- 4301 Circuits 5.00 tors, LED's, zeners, diodes, jack plugs, mains plugs XLR plugs, can- 44 TowersTowers TDriagi;itsailsstoerieEguoirvalent 9.50 non plugs, switches BNC connectors, reducers, photolak, 9.95 developer, PC board, sensitive & normal, boxes, wire cutters, strip- It,Towers Linear 10 Selector 7.50 pers, Edge connectors, pots, batteries, digital pulsers, logic probes, proto-boards, vero board. Why not try our mall order service, it's fast andefficient. We This isjust a small sample of what we stock, if you like to see more take Barclay, Access, Am Exp, Dinersor Cheque. send £1.00 to us for our NEW 1983 CATALOGUE. Cheques made payable to Bradley Marshall Ltd.

PLEASE REMEMBER TO ADD VAT AT 1 5 %+ 70p P&P 36 ETI AUGUST 1983 wi ilzifili /w. ilil NOW lIVE THE AMBIT TOP TENA

* TOBIE DISTRIBUTOR OF THE YEAR *

place ofthe COSTAL'FITER receivers, in first* ofCB mostsignificant for the the single rnostCircuits. (\crystal filterMet canperform modin and cross Band Width.. usual cetarhic 10.-11AW., Freq.. ImProvernentinblocKingCentre 10M1SA., Model. .99 151c14113dBi;lerrnimp..31d1Price..1 S1000.20402 AA NICADS C NICADS

High quality Ever Ready nickel cadmium rechargeableHigh quality Ever Ready nickel cadmium rechargeable batteries. batteries. Size: 14.5x5Omm; 1.2V; Capacity: 500mAH Size: 26 x 49mm; 1.2V; Capacity 2.2AH Stock No. 01.12004Price: 0.80 Stock No. Price: 2.35 ITROBOARD upled ally co a1" pitch only acc BS232 No. holes: MODENLIOTori4inate Stock 36x50; full duplex computerousticwith No. 21-09003 Sizel"): A300 baud any home Price: 3.754,75 Use with 1.14 modem. capability. approvedlil NotPO ....------M-**----...... --IFIVIDION1141.14411.1.... ,,,-1-11:.K-/[11DX,11.1..Z.:l 1111,11111±1""LODIL 7,..; TM. ---4,galPION"..IFva.s.ips47:1614,iii SYSTENL sets OISE SQ of NBFM CR4/RX4 NUELCH.curing thedeficiencies signal level - means of from the is derived A useful etc. Will recharge AA, uting control ignition noise C, D and PP3 size where them influenced by voltage selection. cells with automatic is readily Kit Price.. 412 Price'.19.94 Stock No. 01-02204 Price:8.45 No.41.00201 Price: 7.49 KitStockNo.4044362 Stock Price.12.00 N5.40 Electronics Built Stock StockNo.41412011 Hardware

SCHOrTitIP BAZAIVCCDD LODE

Hermetically AYLMER FET DIP s Sock Stitea 1/6:5d receiver OSCILLATOR Stock No. 0011171 and 1249003 modulator type Stock No.40-16215 rice: 18.79 An essential piece of test equipment for the RF constructor. GDO or absorption wavemeter function covering 215MHz in five ranges. 1.6- adaptable and Fibre -glass PCB, all Z8TB CPU isthe most components, all hardware, punch, based control onthPDSenbasicIdebug on MPU painted and screen printed Based to this design case, wire etc. for coils and understandable entry printed scale. terminalor a home systems. to an RS232 program Needs only tobe connected provide complete configured as one.to computer developmentisupport. Price: 160.00 Stock No.40-00802

Please add 60p postage & packing per order AND LOTS, LOTS MORE IN THE CATALOGUE AVAILABLEFROM JULY ALL PRICES EXCLUDING VAT

Ambit international Telecom directory: tt& F11 Consumer 0277-230909 200 North Service Road Industrial 0277-231616 VISA Brentwood, Essex Telex 995194 AMBIT G - - CM14 4SG DATEL 0277-232628 TELEPHONE SALES 8 am - 7 pm MON - FRI9am -6 pm SAT

ETI AUGUST 1983 37 HOME UGHTING KITS FREE GREEN CATALOGUE, DISCO UGHTING KITS

Thew kits °amain NI mummy cannon...a and Rai ; DL 10001( instrugions Si are d..igned to..place standard well This value for money kit fea- switch and control up to 300w of fighting tures a bi-directionalse- TDR300K Remote Control quence speed of sequence Dimmer £14.30 and frequency of direction MK6 Trikriernitter for above f 4.20 change. being variable by means of poten- tiometers and incorpo aaaaaa master TD3001( Touchdirnmer f 7.00 ALL AT VERY COMPETITIVE PRICES dimming control. ORDERING IS EVEN EASIER-- JUST RING THE NUMBER YOU CAN'T f14.60 TS 300K Touchswitch £7.00 FORGET FOR PRICES YOU CANT RESIST DLZ1000K TDEIK Answennd A lower cost version of the above, featuring switchingforTDbCCk £ 2.50 undirectional channel sequence with speed 5-6-7 8-9-10 service evngs variable by means of a pre-set pot. Outputs LOCIOOK Rotary Controlled switched only at mains ears crossing points Dimmer £3.50 & weekends to reduce radio interference to a minimum. £8.00 Optional opto input DLA1 MINI KITS Allowing audio ("beat") - light MK1 ELECTRONIC THERMOSTAT response 60D Uses LM3911 IC to sense temperature COMPONENTS DL3000K 180°C max) and triac to switch heater a wide range in stock including: This 3 channel sound to light kit features (1KW). Mains powered. E4.00 zero voltage switching. automatic level MK2 SOLID STATE RELAY LM3911 control and built in rote. No connections to t01f 00 TOA1024 4501 24. Switches 240Vatmotors, lights, 1.20 1.20 RF('Ll speaker or limp required. No knobs to adjust LM3914 4511 55. heaters from logic/computer circuits. 7002020 LA TORS 4514 1.15 - simply connect to mains supply end 210 245 lamps. 11Kw channelloniy' Zero voltage switching, opto-isolated. 555 .17 LM3915 713105. 12. 556 .40 7044290 15 VFM £11.95 Supplied without teas E2.60 2.20 1.98 .25 MEd PROPORTIONAL 741 15 LM13600 7%05. 12 JRIlS 748 .35 11061 .40 ELECTRONIC LOCK KIT XK101 TEMPERATURE CONTROLLER 00590 3.30 1_10 T1062 .60 2114 80 LS7220 T1064 70101 12,W Uses -burst fire- technique to main AY.3.1270 .90 15 6810 1 25 LCD 31k DIGIT MULTIMETER This KIT contains a purpose designed lock IC, 2.75 11071 .30 35 taro temperature to within 0.5°C. Ideal 7.20 7905 .40 2716Too 16 ranges including DC voltage (200 my -1000 157225 11072 .50 2732480 10 -way keyboard, PCBs and all components for CA3080 .72 1.543170 v) and AC voltage, DC current 1200 mA-10 AI photography,incubators,wine CA3130 75 2.60 1.014 .95 making, etc. Max. load 3KW 1240V MF 10C 3 30 TL081 25 80 and resistance 10-2 MI + NPN & PNP transistor to construct a Digital Lock, requiring a 4 -key CA3140 .43 011.922 4.10 LM3386 IMEM ac/. Temp. range up to 90°C E5.56 ICL71013 TL082.45 gain end diode check. Input impedance 10M. sequence to open and providing over 5000 041.924 1_95 71.084 45 280A coo MKS MAINS TIMER 700 ML925 2.10 TL170 40 LA4723411/ z 85 Size 1550138x31 men. Requires PP3 9v battery. different combinations. The open sequence Mains powered timer enabling a load ICL9107 PAL 920 1.40 ZBOA nc Teat leads included 900 TL507C 2 60 ONLY E29.00 up to 1KW at 240V ac to be switched M1.927 1.40 1.80 EMI may be easily changed by means of a pre - ICL7126 M1928 1.40 ZEIOA po on for off) for a variable time from 20 8.00 UA2240 4000 .11 250 wired plug. Size: 7 x 6 x 3 ems. Supply: 5V to iCL8030 M1929 1.40 1.20 400' .I1 mot, to 35 hrs.Longer or shorter MM74C911 4002 .11 80351 5.50 3.10 0152003 15 V d.c.at 40uA. Ouput: 750mA max. periods possible with minor CM05555 6.50 .80 4007 .12 HOME CONTROL CENTRE component changes. E5.01/1 MM74C915 ULN2004 4011 .11 Hundreds of uses for doors and garages, car 79 .96 .55 MK15 DUAL LATCHED SOLID LF351 44 4012 .12 T his kit enables yOU to control up to 15 different MM74C922 4013 .20 anti -theft device, electronic equipment, etc. STATE RELAY 16353 BO 2N414 .95 appliances anywhere in the house from the 16356 90 2.90 25426 3.40 4015 .39 MM74C926 Red 9p cornfort of VOW armchair. The transmitter Will drive most relays direct. Full instructions Comprises two MK2s with latch circuit LM324 35 ZN427 5.70 4016 .20 enabling the MK12 kit to control two 4-90 25428 A10 40,7 29 Greene, iiiects coded pulses into the mains which are LM33.2 .90 Yellowt20 supplied. mains loads LM3352 5E566 1.40 2N1034E 4019 .24 decoded by receiver modules connected to the independently. Two 5E567 .97 yag 4023 ONLY £10.50 1:20 15 same mains supply and used to miter, on the outputMatsnot supplied. (See 55660 2.15 4025 .15 'it1:cr" 4e0 remote control kits.) LM339 .50 usst,ilt appliance addressed. The transmitteralso Electric lock mechanism for use with latch E4.50 LM348.63 5576D 2.15 UM 40274026 comtout LS1358 45 SA80600 .2g includes a COMPUTER interface so you can pro- locks and above kit £13.50 2.50 400V 4028 .38 Rea 52e gramme your favourite micro (eq. 2X811 to NEW MK19 DC CONTROLLED LM377 1.45 51.400 1.75 elesee 4040 ToCiliOyi LM380 80 1 6A .39 switch lights. heating. electric blanket, make AUDIO AMPLIFIER 51.4411.35 .42 4043 .38 Soon FlOun0 May be used with virtually any stereo LM381 1.15 51.480 1.70 4A 49 50o yourmorningcoffee, etc..automatically LM362 1 00 4046 .46 Rectangular audioamplifier 51.490 2.40 BA 58 4049 .21 without rewiring your house. JUST THINK OF tocontrol bass, L M386 75 124 5p 184800 .85 4050 .21 THE POSSIBILITIES. The kit includes ell PCBs volume, treble and balance remotely LM1458 35 16A 95 "OPEN -SESAME" LM1830 48 4060 A2 DIS and components for one transmitter and two either using a wire link or the MK11 78081005 25A ISO 4069 .13 The XK103 is a general purpose infra -red transmitter/ Mfrs red receiver. A 1of 10 decoder 140 04006LT Pt ens receivers. Pius apre.drilledboxforthe LM2917 t.00 4070 .13 receiver with one momentary (normally open] relay with LEDS is also included for remote TNIS1121 85 4071 .13 transrKiter contact 1.60 MO03020 3 c.r. Rad and twolatchedtransistoroutputs. input selection/display. (See remote LM 3900 48 0.50 4077 .18 50 TMS1601 1.10 4081 .12 Order as XK112. £42.00 Designed primarily for controlling motorised garage control kits. I (10.70 L M3909.60 Diac 5cc doors and two auxilliary outputs for drive/garage 10.00 713 4093 20 Soo 859 lights at a range of up to 40 h. The unit also has Additional Receivers XK111 E 10.00 numerous applications in the home for switching lights, TV, closing curtains, etc. Ideal for aged or disabled persons. The Kit comprises a mains powered receiver, a tour button transmitter, complete with pre -drilled box. REMOTE CONTROL KITS requiring a 9V battery and one Polo -isolated solid 'JUPITER ACE FOR A DETAILED BOOKLET ON REMOTE CONTROL state switch kit for interfacing the receiver to mains - and 300.8" x 9" S.A.E. appliances. As with all our kits, full instructions are MK6 SIMPLE INFRA RED TRANSMITTER supplied. MICROCOMPUTER Supplied with hand-held plastic box. Requires 9V 117031 battery E4.20. ONLY £23.75 uses FORTH which executes about 10 times faster and PAK 7 INFRA RED RECEIVER requires less program memory than a comparable program Mains powered with thee Output to switch up to 500W at 240V se. Range approx. 20 ft. enroll or using basic. Features 8K ROM, 3K RAM, built in speaker, mornentery control. E9.00 XK113 MW RADIO KIT 40 key keyboard and a 32x. 24 line flicker free display on TV. Inc 5001( -specialpricefor MK61MK 7 MK9 4 -WAY KEYBOARD E12.501 Based on ZN414 IC, kit includes PCB, wound Comes supplied complete with leads, mains adaptor, a comprehensive For use With MK 18/MK 12 transmitter receiver aerial and crystal earpiece and all components easy -to -follow manual on Forth programming FREE cassette where only 4 channels are required E1.90 to make a sensitive miniature radio. Size: 5.5 x MK10 16 -WAY KEYBOARD containing 5 sample programs. £2O0awns"eq MK11 10 Owing' 3 amainua ore receiver 2.7 x 2cms. Requires PP3 9V battery. IDEAL A mains powered LR receiver providing control FOR BEGINNERS. £5.00 ONLY£75.00' VAT, signals to 10 on/off and 3 analogue circuits. May be used for controlling the volume of an amplifier. JUPITER ACE SOFTWARE brightness of a lamp, etc. E12.00 DRAGON 32 MKI2 16 -CHANNEL LR RECEIVER 3 -NOTE. DOOR CHIME da J3 SPACE INVADERS £3.90 A mains powered LA Receiver providing up to 16 £143 + Marriage outputs for switching. £11.95 Based on the SAB0600 IC the kit is supplied J4 SWAMP MONSTERS £3.90 MKIII based on the 51.490. This kit includes all with all components, including loudspeaker, J5 DOT MAN £3.90 components,. make seeded transmitter. Requires if printed circuit board, a pre -drilled box 195 x ORIC 1 (48K RAM) PP3 batteryand keyboard WKS, MK10orMIt131 sire B x 2 x 1.3cm Range approx. 50 ft.E6.20 71 x 35mml and full instructions. Requires WHY NOT COME IN AND SEE MK13 11 way keyboard for use with MKIEI end MK 11 only a PP3 9V battery and push -switch to £143 + E2.socarriage kite 14.35 complete. AN IDEAL PROJECT FOR BEGIN- IT FOR YOURSELF! NERS. Order as XK 102. £5.00 ALL PRICES EXCLUDE VAT COMPONENT PACKS DVM/ULTRA SENSITIVE PACK 1650 Resistors 47 ohm to 10 Mohrn THERMOMETER KIT 10 per value E4,00 This new design is based on THE MULTI -PURPOSE TIMER HAS ARRIVED PACK 240 a16V Electrolytic Capacitors the IC17126 (a lower power Now you can run your central heating, lighting, hi-fi system and lots 106F to 10000F - 5 per value E3.25 version of the ICL7106 chip) PACK 360 PolyesterCapacitors 0.01to more with just one programmable timer. At your selectionitis F4P and a 31/2 digit liquid crystal designed to control four mains outputs independently, switching on dVIS 1pF/250V - 5 per value £5.55 display. This kit will form the and off at pre-set times over e 7 day cycle, e.g. to control your central rr PACK 445 Sub -miniature Presets 100 ohm to basis of a digital multirneter 1 Mohm - 6 per value E2.90 heating(includingdifferentswitchingrimesforweekends),just (only a few additional resistors and switches connect it to your system programme and set PACK 5 30 Low Profile IC Sockets 8, 14 and 16 are required -details supplied), or a sensitive it and forget k -the clock will do the rest. - pin - 10 of each 52.40 digitalthermometer PACK 6 25 Red LEDS I 5mm dial E1.25 1-50°C . to+150°C) FEATURES INCLUDE:- readingto0.1°C.Thebasickithas a 0.5' LED 12 hour display. Nowonlc.'.."\., sensitivity of 200mV4or a full scale reading, Day of week, ern/pm and output status indicators. automatic polarity indication and en ultra 4 zero voltage switched mains outputs. £39.00 low power requirement -giving a2 year 50830112 mains operation. OPTIONAL BLACK 24 HOUR CLOCK/ typical battery life from a standard 9V PP3

when used 8 hours a day. 7 days a week. Battery backup saves stored pcogramMes and continues PLASM CASE. READY APPLIANCE TIMER KIT time keeping during power failures. (Battery not supplied). Price £15.50 Display blanking during power failure to conserve battery power DRILLED £2.50 Switches any appliance up to IkW On and off at 18 programme time sets. preset times once perday.Kitcontains: Powerful "Everyday" function enabling output AY -5-1230 IC. 0.5" LED display, mains supply, Add 65p postage &packing + 15% VAT to to switch every day but use only one time set. display drivers, switches, LEDs. triacs. PCBs total Overseas Customers; Useful "sleep" function -turns on output for one hour. (Kit includes all components, PCB, and full instructions. Add £2.50 (Europe), £6.00 (elsewhere) for CTIOOOKBasicK it £14.90 Direct switch control enabling otttput to be tumor) oar assembly and programming P&P. immediately or after specified time interval. CT1000K with white boo Send S.A.E. for further STOCK DETAILS, 20 function keypad for programme entry. instructions). ORDER AS CT5000 158/1310 71mm1 ...E17 AO Goods by return subject to availability. Programme verification at the touch of a button. (Ready Built I E22.50 5pm (Mon to Fri) OPEN9am10am to to 4pm (Sat)

ALINGS NOR CLOCK TOWEFI fta,11.AR RD'AM.

MIT SERVICETIP QUALITY. LOW LOW PRICES No circuit is complete without a call to - CAR HANINELL ELECTRONICS PARK LT GARAGE ACCESS TEL 01-567 8910 ORDERS 11 Boston Road and 01-579 9794 ENQUIRIES s BARCLAYCARD London W7 3SJ welcome 01-579 2842 TECHNICAL AFTER 3PM 38TK ETI AUGUST 1983 FEATURE IC UPDATE Dear Reader, What we've indulged in here is a slightly speculative venture, in that neither of the two ICs featured this month are actually available to the hobbyist, so far as we know (if you're in industry, then you'll be able to get the 1M2877/8 from your Nat Semi supplier, and the RC4193 from Raytheon). However, we think that by bringing these to the light of day, we shall motivate someone, somewhere to stock them. And far be it from us to suggest ouradvertisers, but a word in their ear from you may not go amiss ... RC41 93 Switched Mode PSU What, not another switched mode PSU? Well, yes, but this one can keep your trannygoing for longer, amongst many other applications.

The RC4193 is a monolithic switching regulator IC VF, is greater than 1.31V. note when the output of Al of A2 that, with very few external components is capable of is high the switch transistor Q1 cannot turn on. stepping up or down, or inverting, with atypical effi- The oscillator has its frequency determined by a single ciency of 80%. capacitor C, and outputs two waveforms, a square wave and a tooth V (which appears at pin 2) both of which appear at the input of A2. The portions of the waveform where Qi can be saturated as a result of the oscillator, are labelled Tc in Fig. 2, and the portion of the LOW BATTERY waveform where Q1 would be off is labelled To. Q1 can DETECTOR

MAX ON Vow- HIGH TIME WITH VOUT LOW 11, OFF

01

ON TONIuS)MAX = 0.206 Cx(PF) ToFFIuS)MIN = 0.261 Cx(PF) Fig. 2 Switching timing diagram.

be saturated only when VFB is less than 1.31V. The voltage of the sense line from the R3/R4 voltage divider at the VFB pin is directly proportional to the output voltage VoUTt where VOUT = 1.31 (R3 + R4)/R4. When V, isless than Fig. 1 RC4193 functional diagram. 1.31V, Qi will saturate on every negative going oscillator cycle until VouT reaches the programmed value. Principles of Operation The 4193 also includes an uncommitted comparator The circuit has an on chip 1.31 V band gap reference and output transistor shown as A3 and Q2 in Fig. 1. The with a typical TC of 5Oppm. In addition to setting the bias 1.31V internal reference is used as the threshold at the + currents in the 4193, this voltage is used as the reference at input of A3. The voltage divider R2/R5 is used to deter- the input of comparators Al and A3. The 1.31 Vat the in- mine the voltage at which Q2 switches. When the voltage put of Al is used as the threshold to compare to the feed- at LBR (pin 1) falls below 1.31V then Q2 will saturate. A3 back output voltage at pin 7 (VFB). The output of Al is fed has about 0.7µA of hylteresis to produce a positive turn to a NOR gate which is used to gate the output of the on/turn off at LBD (pin 8). The voltage at which Q2 swit-. oscillator comparator (A2) which turns off Q1 whenever ches is determined by V - 1.31 (R2 + R5)/R5. ETI AUGUST 1983 ed with any input between 9.3V and 2.4V. Absolute Maximum Ratings If a lower supply voltage can be tolerated, the output Internal Power Dissipation 500mW of the 4193 can be set to start regulating at 7V (1.16V/Cell), Supply Voltage (without external effectively keeping the 4193 in its quiescent state (drawing series pass transistor) 24V only 1500) until the battery voltage falls to 7.5V. Below Operating Temperature 7.5V the 4193 will regulate the VouT at 7.0V until the bat- Range 0°C to + 70°C tery falls below 2.4V. In this circuit R2 and R5 are used to Switch Current (lsw) 150mA indicate a low battery condition when the input voltage Reference Set Current (Ic) 1 mA falls below 5.9V; any other voltage can be selected by VE, LBR, C,Voltage changing the value of R2. If the Lov-v Battery Detector cir- L, LBD Voltage 24V cuitry is not going to be used, leave pin 1 and 8 uncon- nected. As mentioned previously, the top of R5 can also be connected to V°, when a low output indication is

PARAMETERS CONDITIONS MIN TYP MAX UNITS

Supply Voltage, Vcc 2.4 24 V Reference Voltage (internal), VREF 1.24 1.31 1.38 V Switch Current, 15, V, = 400mV 75 100 mA Quiescent Current, I Measure at Pin 5 I, = 0 135 200 uA Efficiency 80 Line Regulation 0.5V, < V- V, 0.08 0.5 VOUT Fig. 3 Basic circuit for stepping up Load Regulation Vc, = 0.5V, mode. P, = 150mW 0.2 0.5 % V, Operating Frequency, f, 0.1 25 150 kHz

Reference Set Current, I, 1 5 50 uA

Switch Voltage 1, = 100mA 0.4 1 V Switch Leakage Current V, = 24V 0.01 5 uA Supply Current (Disabled) I, <0.01uA 0.1 5 uA Low Battery BiasCurrent V, = 1.2V 0.7 uA Capacitor Charging Current 5.0 uA Capacitor Threshold Voltage + 1.78 V Capacitor Threshold Voltage - 0.62 V Fig. 4 Basic stepping down circuit. Feedback Input Current V, = 1.3V 0.1 uA Low Battery Output Current V. = 0.4V, V, = 1.1V 100 600 uA

Table 1Electrical characteristics Step Up Step Down Inverting The 4193 series circuits contain an internal bias net- work which maintains the correct operating currents to VIN - 1.2 VIN - 1.2 R1(M) Vg.j - 1.2 the 4193 independent of temperature and input voltage 5µA 5µA 5µA variations. The internal bias network is turned on by sup- VIN - 1.31 VIN - 1.31 R2(M) V,,,, - 1.31 plying a current I, between 1µA and 100µA into pin 1, and 5µA 5µA no change willresuiltin the operating characteristics 1.31 VouT - 1.31 when I, is varied over this range. To shut down the 4193, R3* VOUT VOUT simply force pin 1 to less than 0.5V by using a mechanical I, I, 1.31 switch or open collector transistor. The quiescent current R4* 1.31 1.31 in the 4193 will fall to less than 5pA (typically less than 0.1pA). R5 2611(0 261kil 261kO 2.14 x 106 2.14 x106 2.14 x 106 Design Equations Cx (pF) fo fo fo Table 2 is a set of design equations which can be used to determine resistor, capacitor and inductor values for 0.3 Vg (VOUT VIN) 0.3VOUT 0.3VINIVouTl step-down, step-up and voltage inverting applications. To Lx. use the equations, you determine the oscillator frequency f0 LOADVIN f0 I LOAD folLoAD(V,,,,+ 'Vow!) (f0), input voltage (VIN), output voltage (VouT) and max- CI 2Vour VIN 0.15I,,N + 2 Mud) imum output load current (k). 4fOVOUTVR foVIN(VIN + lVourl)VR 35 R6 35V Basic Step -Up Switching Regulator I LOAD VOUT LOAD I IDAD(VIN + I VOUT I) Figure 5 is the basic low current step-up configuration R6 R6 R7 R6 to be used for most battery powered applications requiring 7 7 7 less than 150mW of load power (when VIN > 0.5 V001). Units are ohms, fards, henries, and hertz unless The output voltage VouT is determined by the expres- indicated otherwise. sion 1.31 (R3 - R4)/R4; in this case Vour would be 9.0V. I, = current into pin 1; recommended value 100uA. This configuration makes a good subsititute for a 9V tran- sistor battery, since a stable output voltage will be achiev- Table 2 Design equations for the three modes. 40 ETI AUGUST 1983 FEATURE : IC Update

The 2N2907 replaces 51 of Figure 4, and R6 and R7 are ad- VOUT 9V ded to provide the base drive to the 2N2907 in the correct polarity to operate the circuit properly; refer to Table 2 for equations for component values. Since the1.pinis capable of sinking 100mA, high current switching tran- sistors can be used in place of the 2N2907.

LOAD CURRENT

2N2907 VOUT

Fig. 5 RC4193 tow current step-up mode. desired. VIN A feature of the 4193 is the ability to shut off when pin 6 is forced below 0.5V. An example of this feature is shown in Fig. 6. In this circuit as long as Vc remains low the output will regulate to 5V. This type of circuit can be used to back up the main supply voltage when line interrup- Fig. 8. RC4193 step-down mode. tions occur, a particularly useful feature when using volatile memory systems. Greater Than 30 Volt Application Adding a zener diode in series with the base of the 2N2907 allows the input voltage to increase by the value VO - 5V of the zener, with only a slight decrease in efficiency. As an example, if a 24V zener is used, the maximum input voltage can go to 48V.

LOAD CURRENT VOUT

Fig. 6 RC4193 battery -back-up circuit. vi In step-up application, power to the 4193 can be derived from the output voltage by connecting the V, pin and the top of WI to the output voltage (for example see Fig. 7). One requirement is that the battery voltage must Fig. 9 RC4193 used as an inverter -regulator. be greater than 3.0V when the circuit is energized or else there is not enough voltage at the V, pin to operate the Inverting Switching Regulator 4193. However, once running, the battery can decay to Many single -supply systems require an occasional 1.0V before the circuit stops operating. negative voltage for a specific application; this circuit will meet those needs. The circuit is similar to the type used in Fig. 8, except the lcoation of Lx and the diode are reversed and a micropower op -amp RC3078 is added to provide inver- sion forthe sense voltage. The output voltage is 1.31 R3/R4. The RC3078 operates at a closed -loop gain of close to one in most applications, therefore the value of Cc must be such to frequency compensate the RC3078 for unity gain conditions. The value for R, will determine the quiescent current in the 3078 and for micropower applications can be set to operate at approximately 10µA. Where a larger amount of amplifier quiescent current can be tolerated, a ground sensing op -amp such as the LM324 or RC3403A can be used, eliminating the need for R and Cc. An important point is that pin 7 must be below 1.3V Fig. 7 Bootstrapping the supply to the RC4193. when IV0,,TI is below the design output voltage or else the circuit will not start. Basic Step -Down Switching Regulator Due to their output stage design, op -amp types similar Since the switch transistor in the 4193 is in parallel' in design to the 741 may cause the circuit to not start pro- with the load a method must be used to convert it to a perly since they fail to keep pin 7 below 1.3V when power. series connection; the circuit of Fig. 8 accomplishes this. is first applied.

ETI AUGUST 1983 41 LM2877/8 Audio Power Amps The LM379 has had a good innings as linear ICs go, but it'snow being replaced by the LM2877 and LM2878 in manufactured equipment.

BIAS

The LM2877/8 are monolithic dual power amplifiers OUTPUT 1 designed to deliver 4W (2877) or 5W (2878) con- tinuous into eight ohm loads. Each power amplifier is GND biased from a common internal regulator to provide good INPUT 1 power supplyrejection and output centering.Both FEEDBACK 1 devices are internally compensated for gains greater than 10 and come in 11 -lead single in -line packages. .GND

FEEDBACK 2

INPUT 2 PIN 6 CAN BE CONNECTED Absolute maximum ratings TO PIN 3 OR PIN 9.1F NOT. PIN 6 MUST BE LEFT WITH Supply voltage 26 V (35 V 2878) GND NO CONNECTION Input voltage +0.7 V Operating temperature 0°C to +70°C OUTPUT 2 Junction temperature 150°C v+ Fig. 10Output connections. Electrical Characteristics for LM2877: Where those of the LM2278 differ, they are given in ; otherwise the same figure applies. vs - 20V (22V), TTAB = 25°C, R, = 80, Av = 50 (34 dB) unless otherwise specified Note 1: For operation at ambient temperatures greater than 25°C, the LM2877 must be derated on a maximum 150°C junction temperature using a thermal resistance which depends upon device mounting techniques.

PARAMETER CONDITIONS MIN TYP MAX UNITS

Total Supply Current P, = OW 25(10) 50 mA DEVICE DISSIPATION us AMBIENT TEMPERATURE 10 ALUMINIUMTHICKNESSI= 1/16IINCH Operating Supply Voltage 6 24(35) V 9

8 N... INFINITEHEATSINK ALUMINIUM Output Power/Channel f = 1 kHZ, THD = 10%, TTAB = 25°C 15° C/W 7"--1 x1 IN 45.8°CA V5 = 20V 4.0(5.0) 4.5(5.5) 1.4 a1.4 IN39° CAN -2x 2 IN33. CM Vs - 12V, R5 = 40 1.5 1.9 3,31N20. OW

TYPICALCHASSIS Distortion, THD tax, 25° C/W f=1 kHZ, Vs = 20V 4 Po = 50 mW/Channel 0.1(0.2) 3 -a-Pilitill.IN:-Im...._ P, = 2W/Channel 0.07(0.14) 1 2 FREE AIR 65°C/W Output Swing R5 = 811 Vs -4 Vp-p

(V5-6) 0 Channel Separation CF = 50 uF, C. = 0.1 uF, f = 1 kHz 0 10 20 30 40 50 60 70 80 Output Referred TA -AMBIENT TEMPERATURE I.C1 V5 = 20V, V, = 4 Vrms -50 -70 dB Fig. 11 Device dissipation vs. PSRR Power Supply CF = 50 uF, CIN = 0.1 uF, f = 120 Hz, ambient temperature (LM2877). Rejection Ratio Output Referred V5 = 20V, VRIPPLE = 1 Vrms -50 - 68( - 60) dB POWER DISSIPATION vs POWER OUTPUT Noise Equivalent Input Noise R5= 0, CIN= 0.1 uF, 2.5 uV BW - 20 Hz -20 kHz Open Loop Gain Rs = 0, f 1 kHz, 125 = 80 70 dB 20V THD= 3%

Input Offset Voltage 15 mV

wa Input Bias Current 50(100) nA di THD=10% Input Impedance Open Loop 4 MO

DC Output Level V5 = 20V (22V) 9(10) 10(11) 11(12) V

2 3 4 Slew Rate 2.0 V/us POWER OUTPUT IVV/CHANNE LI Fig. 12 Power BandWidth 65 kHz Power dissipation vs. power output (LM2877). Current Limit 1.0(1.5) A

42 ETI AUGUST 1983 FEATURE : IC Update

2k 100k

8R

8

Fig. 15Non -inverting amplifier using split supply.

Fig. 13Ceramic PU amplifier with bass control.

FREQUENCY RESPONSE OF BASS TONE CONTROL 65

MAXIMUM 10 BOOST 2 RESPONSE OUTPUT 1 1UTPUT 2

TONE CONTRO FLAT A

36

a MAXIMUMCUT RESPONSE 25 O

6 1 1520 -FEEBACK 1 GND +INPUT 2 -FEEOBACK 2 50 100 200 600 1k 2k 5k10k20k FREQUENCY MP/ Fig. 16Internal circuit. Fig. 14 Frequency response of bass control in Fig. 13. Next month we'll take a look at a few more newcomer ICs.

If youmisseddboard . outon Breaand'82 . .up '79,'80,'81timetocatch Now'sthe '83 withBREADBOARD The premier electronics show for the enthusiast. This year's features include Moved this year for your convenience and comfort to the Cunard International Hotel, Hammersmith, Computer controlled model railway competition. London W6 (send off for entry form now) Friday November 25th 10am - 6pm Kits to build all sorts of projects. Saturday November 26th 10am - 6pm Magazines and books covering most aspects of Sunday November 27th 1 electronics. Why no a Components and tools at bargain -prices. weekend lete Technical advice on electronics projects and Ham hotel pa .All Radio technique. inclusiv Or details o c n offer you. Clubs/User groups for amateur electronics and Write to computing Breadbo '83 Lectures by professionals on a wide range of ASP Exhibitions topics. eg. Basic Tuition For Beginners, 145 Charing Cross Road Holography and Producing Printed Circuit London WC2H OEE Boards.

ETI AUGUST 1983 43 ORIC SOFTWARE from TANSOFT

ORIC ORIC CHESS ZODIAC FLIGHT A superb chess game written in A 36K adventure game that will test Can you fly your new 787 jet on to Basic with a Machine Code Move your intelligence and patience for the runway without crashing, Search Routine. Features high hours. Find the 12 hidden signs of stalling or running out of fuel? resolution colour graphics, record of the Zodiac to discover incredible Full digital instrument readout plus moves, allows Castling and treasures. Can you ward off the cockpit view of final runway En -Passant. 5 levels of play and angry Yeti? What is the meaning of approach. Superb graphics and computer can play black orwhite. the radio that plays the 'Archers' sound. ONLY £9.99 inc VAT over and over again (through your Only £.7.95 inc VAT 48K only loudspeaker!)? 48K only Only £9.99 inc VAT 48K only

Please send me I Quantity ITotal Name All cheques payable to

Oric-Chess at £9.99 I Address TANSOFT LTD I 3 CLUB MEWS Zodiac at £9.99 ELY Oric-Flight at £7.95 I CAMBS CB7 4NW TOTALI Please send me latest price list Tansoft is the software division of Postageper cassette is 40p Please allow 28 days for delivery Tangerine Computers. PROJECT UNIVERSAL EPROM PROGRAMMER Get to grips with the bits usingour Universal EPROM programmer. Design and development by Mike Bedford.

EPROMs provide a convenient however, as electronically it should has been provided on PCB. This means of storing commonly be quite simple to interface this decision was taken on grounds of used software, but many micro- card to any computer using the economy and some constructors may computer users are deterred from 6502 or 6809 processors. No special prefer to add a 24 -pin socket in using this media due to the power supplies are required as all addition. If a single 28 -pin socket is difficulties of erasure and voltages required for programming used, 24 -pin devices should be programming. EPROM programmers are derived from a single +5v inserted intothe bottom part of the are both commercially available and supply. socket, ie leaving pins 1, 2, 27 and 28 have been featured as Although the PCB has sufficient empty. Table 1 shows the pin outs ofall constructional articles in some space for a zero insertion force EPROMs which are supported. magazines, but the former are socket to be mounted on board, it The programmer applies relatively expensive and the latter is probably more convenient, a TTL level to all pins with the tend to be limited as regards types especially if the card is to be rack exception of pin 1 which is of EPROM supported. For these mounted, to mount this socket in a connected to Vpp, pin 14 (OV) and reasons, it was considered separate console, making a pin 28 (+5v). Vpp is program appropriate to develop a universal connection with a length of ribbon selectable to +25 V, +21 V or +5 EPROM programmer which could cable. Note that a switch should be V and may also be applied to pins be built by the amateur for a provided on the console to isolate 22 and 23 as an alternative to a TTL modest sum. The programmer Vpp and Vc,on pins 1 and 28 level. To summarise this presented here will support the respectively. This is necessary since information, the programmer may following EPROMs: 2758, 2716, inserting or removing an EPROM be considered as a glorified 29 -bit 2516, 2732, 2732A, 2532, 2764, with these supplies present may output port. This being the case, 2564, 27128 and 27256. This list result in its destruction. and since the circuitry required to includes every single supply version If the console is not used, implement the above would not of the 27 -Series and 25 -Series switch SW1 should be mounted on completely fill a 8" x 41" PCB, it devices up to and including 256k bit board to isolate these supplies. On seemed appropriate at the cost of capacity, which seems likely to be EPROMS which have Vpp and V« on only two more ICs to add four the largest EPROM which will be other pins, these supplies may be additional 8 -bit output ports to produced as further development isolated under program control. It make maximum use of the board will probably be of EAROMs and will also be noticed that only a space available. These ports are EEPROMs. The programmer is single zero insertion force socket completely independent from the intended for use in conjunction with a 6502 computer system and appropriate software is presented. Although the hardware is designed to support the 27256, this one EPROM is not as yet supported by the software due to lack of preliminary data on this device, the chip itself having not been released by the manufacturer at the time of writing. To complete the requirements for programming EPROMs, some hints are given on building an erasure unit. Hardware The hardware has been designed for a Tangerine Microtan system, the physical dimensions of the circuit board being selected such that it will plug directly into

the system rack. Non -Tangerine The Universal EPROM Programmer Note that this prototype differs slightly from the final users should not be deterred, version - in particular, the component numbering is completely different!

ETI AUGUST 1983 45 +5V

IRO

RST0 0 Al 8

ICla 6 AO 0 13 IC1n 020 12- 11 IC1c R/T)i

IC1c1

DIR DB7 0 12 DB6 0 8 13 DBD 0 14 DB4 0 15 IC2 DB3 0 D82 0 16 17 DB1 0 18 OBO 0 EN G

10 0 HEADER SOCKET 0+5V 1C3a 1 FOR LINKS) CI 7.1 IM M 8 13 12 22 14 IC6 24

A9 0 IC31, N MRIn con 020001 ,-NCIcrinWC.00M 6 15 0 10

16 5V

A8 0 .1 12 IC3r. C5 11 11 10 17

5 023 YO M0MWN0001R,7, 8 G2.;

5V R9 OR22

OUT 14 8 R7 15k TC3 1;400 100n 470u 10 IC11 12 15 /77T7 R8 3 C4 16 RV3 680R 4n7 2k2 2 L1 (SEE R5 TEXT) 5k1

PIN 14 IC1,3,4 4 0k4 +5V 0 PIN 20 IC26,7,8,9 PIN 16 105 PIN 13 IC11 C8 1C9 1C10 T100n 100u PIN 7 IC1.3,4 03 PIN 10 IC2

OV , 111, PIN 8 IC5 PIN 1 IC6,789 PIN 11 IC11 Fig. 1 Circuit diagram of the Universal EPROM Programmer. The design is based around four 6821 programmer. 3. Test an EPROM for erasure; 20 -bit PIOs. The circuitry comprising 4. Program an EPROM from data in 1C3, IC4 and IC5 provides the interface to the Tangerine bus and, in conjunction Software computer memory, verifying each with the links, allows the board to be In order to be a useful byte as it is written. configured to occupy a 16 -byte block development tool, the following In fact, some additional functions within the 1k I/O area. IC1 and IC2 are functions are the minimum have also been added and these will used to buffer various signals in order that no more than one TTL loadis requirements of an EPROM be described under the section on presented to any bussed input. Of the programmer: using the EPROM programmer. four 6821s, IC6 and IC7 provide the four 1. Read data from an EPROM into Table 2 is a mode selection independent I/O ports. These being con- table for all supported devices, nected to the outside world via SK1 and computer memory; SK2, whereas IC8 and IC9 are used to 2. Compare the contents of an showing the read, program, verify drive the EPROM programmer. Most of EPROM with the contents of and standby modes, these being the the signals required to drive the pro - computer memory; modes necessary to implement the

46 ETI AUGUST 1983 PROJECT :EPROM Programmer

+5V 1-5V +5V O gi ;7) g E N Nc5VP, ,1: M O gi c91 Pi 71 e.t `AP., M M g ?g; N N N M g 7.,177`)

22 IC7 24 'CO IC9 +5V

ot-NCIVI.OtONNN4 (OM R2 01 lkO 10k Q2

01

O CC tO NI26

R3 100k SK2 SK3

I; co

011 R12 R13 R14 10k lkO 10k 1k0

05 06 07 08

C5I Fil5 1°" "k

/7777

HOW IT WORKS grammer are TTL levels and are taken levels under different conditions, they components L1 and C4. Although this directly from the two 6821s to the ZIF arealsoconnectedto6821 ports, componentshould be capableof socket, SK3. Pin 26 on SK3 is slightly dif- isolating these signals by u$e of Ger- regulating V, to within the required ferent in that although it is a pure TTL manium diodes D1 and D2 respectively. limits, experiments showed that it is ad- signal on all 28 pin devices, it is the V It should be noted that when a 6821 visable to select R7 and R8 such that supplyonallEPROMsin24 -pin is required to drive a transistor, A 'B' IC11 would output about + 30 V and use packages and hence requires a much port is used, these having a greater cur- a separate LM317MP regulator to give greater current capacity than is available rent sourcing capacity than 'A' ports, the required voltage. Since V, may need from a port on a 6821. Q1 and Q2 are and when a port needs to be isolated by to be +25 V, +21 V or +5 V, Q3 and therefore used to switch the +5 V supp- a diode, an 'A' port is used as these give Q4 are used, to switch out portions of ly to SK3 pin 26 under the control of a full +5 V high signal so that, even the resistor chain between the regulator IC9/CB2 (pin 19). A similar technique is allowing for the voltage drop across the adjust terminal and 0 V hence altering used to switch V onto SK3 pins 22 and diode, a good TTL high is presented. The the output voltage. These two transistors 23 using transistor pairs Q5/Q6 and Nip, supply is generated from the +5 V are connected to IC8 PB4 and PB5 (pins Q7/Q8 respectively. Since these two pins supply using IC11, a 78S40 switching 14 and 15) hence allowing V to be on SK3 are also required to present TTL regulator IC, in connection with timing changed under program control.

ETI AUGUST 1983 47 27 27 25 27 25 27 27/ 27 IC/ IC 27 27/ 27/ 25 27 25 27 27 256 128 64 64 32 32/ 25 58 PIN PIN 58 25 32 32 64 64 128 256 32A 16 16 32A

I I VPP VPP VPP VPP -/1 C ] - /28 VCC VCC VCC VCC

A 1 2 Al2 CS) Al2 /2 C ] /27 PGM CS2 PGM A14

I I A7 A7 A7 A7 A7 A7 A7 A7 1/3 C ]77 24126VCC VCC VCC VCC N/C N/C A13 A13

A6 A6 A6 A6 A6 A6 A6 A6 2/4 C ] 23/25A8 A8 A8 A8 A8 A8 A8 A8

A5 A5 A5 A5 A5 A5 A5 A5 3/5 C ] 22/24A9 A9 A9 A9 A9 A9 A9 A9

VPP VPP 411 VPP All A4 A4 A4 A4 A4 A4 A4 A4 4/6 C ] 21/23 All Al2 All PD/ PD/ A3 A3 A3 A3 A3 A3 A3 A3 5/7 C ] 20/22OE OE OVPEP OE PGM OE OE

C A10 A10 A10 A10 A2 A2 A2 A2 A2 A2 A2 A2 6/8 ] 19/21AR 410 A10 410

Al Al Al Al Al Al Al Al 7/9 C ] 18/20 PCGE/M PGM CE All CE All CE CE NOTE: AO AO AO AO AO AO AO AO 8/10 C1,PIN NUMBERS TO ] 17/19D7 D7 D7 D7 D7 D7 D7 D7 28PIN PACKAGES. sp2rFROARC2T42F,FI NR OP AMC PKI NA SG DO DO DO DO DO DO DO DO 9/11 C ] 16/18D6 D6 D6 D6 D6 D6 D6 D6 PINNUMBERS.

D1 D1 D1 Dl D1 D1 D1 D1 10/12 C2)OE (27 SERIES) IS 15/17D5 D5 D5 D5 D5 D5 D5 D5 EQUIVALENTTO CS (25 ESERIES). 02 D2 D2 D2 D2 D2 D2 D2 11/13 14/1604 D4 D4 D4 D4 D4 D4 D4 3)CE/PGM (27 SERIES) EISEQUIVALENT TO PD/PGMD GND GND GND GND GND GND GND GND 12/14 (NOT PD/PGM) 125 SERIES). 13/15D3 D3 D3 D3 D3 D3 D3 D3

Table 1 Pin -outs of all the EPROMs our programmer will process. MODE EPROM TYPE FUNCTION PIN READ STANDBY PROGRAMME VERIFY

2758, *AR 19 VIL VIL VIL VIL (FIRST ADDRESS) 27/2516 CE/PGM 18 VIL VIH VIL-VIH VIL I OE 20 VIL X VIH VIL CVCC - 6V Vpp = 21V VPP 21 +5 V +5 V +25 V +25 V

I VIL X = 0 2732/32A CE 18 VIL VIH ( ) OE/VPP 20 VIL X **VPP

(P R0 iGmR,APMUML SE EONE 2532 PD/PGM 20 VIL VIH VPP 21 +5 V +5 V +25 V (X=X. 1 2764, CE 20 VIL VIH VIL VIL 27128 OE 22 VIL X X VIL PGM 27 VIH X VIH-VIL VIH

VPP 1 +5 V +5 V +21 V +21 V

FAIL 2564 PD/PGM 22 VIL VIH VIH-VIL CS1 21 VIL X VIL CS2 27 VIL X VIL PROGRAMME ONE 4 . X ms PULSE VPP 1 +5 V +5 V +25 V

NOTES: FAIL X = DON'T CARE *AR IS ONLY ON THE 2758 PASS ** VPP IS +25 V ON THE 2732, +21 V ON THE 2732A

ADDRESS = NO functions mentioned. It may be ADDRESS a 1 noticed that some devices can perform both read and verify. Table 2 (above) Mode selection table. Functionally, these modes are the (VCC= Vpp 5V same but verify is carried out with V, high, hence simplifying the Fig. 2 (left) Flowchart for intelligent program/verify process. From this programming mode. table it may be seen that there is a

PASS great deal in common between the various EPROMs, hence simplifying the design of software. ETI AUGUST 1983 48 PROJECT :EPROM Programmer

To get the full picture, the be carried out and that there is no Construction And timing diagrams of each device provision in the hardware to select Alignment should be scrutinised, but for the this value of V. under program general user this information is control. This need present no great Although the circuit of the probably not relevant. To problem, however, to the user programmer is of sufficient summarise, however, EPROMs wishing to implement this mode, as complexity that if it were to be generally require about 50 ms to +6v may be switchable from the produced commercially it would program each byte giving total programming console, perhaps by probably be double sided, it is not programming times of from around deriving this voltage from the so complex that a single sided 50 seconds for a 2758 to 13 minutes system + 12V supply. board would be impossible to for a 27256. You may consider Any additions to, or design. It was considered that cost these times rather long, especially modifications of the software will would be of prime importance to an for the larger devices and although need to be made in the light of the amateur building a one-off project, not implemented in the software information presented in Tables 3 and on these grounds it was presented here, there is an and 4. These may be described as a artworked as a single -sided board. alternative programming method programmer's view of the EPROM As a result of this, a number of referred to as the intelligent programmer, Table 3 showing the insulated wire links need to be programming mode which can address of each register and Table 4 inserted prior to fitting the reduce programming times by a indicating which bits of the various components. No special instructions factor of six for the 2764, 27128 and 6821 ports connect to which are required on the fitting of 27256. Figure 2 is a flow diagram of EPROM pins or perform the various components with the exception of the functions which need to be control functions required. socket SK3 and switch SW1. If a performed in order to implement separate programming console is to this method of prorgramming. be used, then an ordinary low Notice that V needs to be profile DIL socket should be used as increased to +6V for this process to SK3, and two wire links should Table 3 Register addresses.

FUNCTION 6821 NUMBER REGISTER OFFSET FROM BASE IC9 DDRA/ORA 00 Table 4 Port, functions. IC9 CRA 01 REGISTERS IC9 DDRB/ORB 02 FOR IC9 6821 SK3 CRB 03 NUMBER/ PIN PROGRAMMER FUNCTION EPROM IC8 DDRA/ORA 04 PORT NO. PROGRAMMER IC8 CRA 05 IC9/PBO 10 AO IC8 DDRB/ORB 06 IC9/PB1 9 Al IC8 CRB 07 IC9/PB2 8 A2 IC7 DDRA/DRA 08 IC9/PB3 7 A3 REG ISTERS IC7 CRA 09 IC9/PB4 6 A4 FOR IC7 DDRB/ORB 10

IC9/PB5 5 A5 GENERAL IC7 CRB 11 IC9/PB6 4 A6 PURPOSE IC6 DDRA/ORA 12 IC9/PB7 3 A7 I/O IC6 CRA 13 IC9/PAO 25 A8 PORTS IC6 DDRB/ORB 14 IC9/PA1 24 A9 IC6 CRB 15 IC9/PA2 21 A10 (EXCEPT 2758), AR (2758) IC9/PA3 23 All (2732/32A/64/128/256), Al2 (2564) replace SW1. On the other hand, if IC9/PA4 2 Al2 (2764/128/256), CS1 (2564) the programmer is intended to be IC9/CB2 26 A13 (27128/256), VCC (2758/16/32/32A, 2516/32) self contained on a single board, a zero insertion force DIL socket IC8/PAO 11 DO 'should be used as SK3 and switch IC8/PA1 12 D1 SW1 is needed. Once the IC8/PA2 13 D2 construction is complete, the links IC8/PA3 15 D3 need to be configured to place the IC8/PA4 16 D4 board at the desired address'. The IC8/PA5 17 D5 offset from the start of the I/O area IC8/PA6 18 D6 is 16 times the binary number IC8/PA7 19 D7 represented by the links. The best IC8/CA2 22 OE (2758/16/38/32A/64/128/256,2516), PD/PGM (2532/64) way to illustrate exactly how the IC8/PBO 20 All (2532/64), CE/PGM (2758/16, 2516), CE (REMAINDER) links are used is probably IC8/PB1 27 PGM (2764/128), CS2 (2564), A14 (27256) graphically; Fig. 3 shows a few examples. IC8/PB2 22 VPP (2732/32A) VPP (2758/16, 2516/32) The other part of the circuit IC8/PB3 23 which requires setting up is IC8/PB4 VPP +5V SELECT* associated with Vppgeneration. This IC8/PB5 VPP +21V SELECT* is very important as EPROMs will be *NOT (VPP+ 5) AND NOT (VPP+ 21V)+25V SELECT

destroyed if V,,is more than OV5 too high. The best way to check this ETI AUGUST 1983 49 1 is with a voltmeter probe on the output of IC2, with IC8 removed from its socket. Apply +5 V to pin 14 of the IC8 socket and adjust RV3 until +5 V is recorded on the test meter. Now replace +5 V on pin 14 0 fffffff nnananatione by +5 Von pin 13 of IC8 socket and adjust RV2 for +21 V on the meter. Finally, remove +5 V from pin 13 of IC8 socket and adjust RV1 VOUVITUVUOU017121701WUVU for a potential of +25 V at IC2 output. Setting up is now complete. Using The Programmer The first stage in using the EPROM programmer is to load and run the support package software which is written in BASIC and assembly code. The user will first be prompted for EPROM type, valid responses being 2758, 2716, 2516, 2732, 2732A, 2532, 2764, 2564 and vvvvvvvvvvvvvvvvvv 27128. A request for a base address will then be made and the user 1K2 should respond with a four -figure hexadecimal number. The base address is the address relative to which all references to computer internal memory are made and this ii1:11111 means that the user does not need WWWWW,VVVY to be concerned with the actual absolute addresses in computer memory. The reasons for being able SKI to select the base address are two fold. Firstly, to fit in with the memory map of any computer on which the software may be run and, secondly, to allow more than one set of data to be maintained at one time by using different base addresses. A table showing all the commands available will the be printed before the *? prompt MEADER FOR LINKS appears on the screen. When this I ILIttoitt prompt indicates that the program is 0 waiting for input of a command, it is safe to insert or remove EPROMs from the ZIF socket, provided, of course, that the isolating switch is in the OFF position for 28 pin devices. The following describes the function of the EPROM programmer support package commands. It should be noted that in each case, either the whole word or the initial letter may be used:- (N)EW, (B)ASE These two EigilY1W 0 commands cause the user to be prompted for a new EPROM type or a new base address respectively, Overlay diagram of the programmer. hence allowing these two parameters to be altered without as two four -figure hexadecimal addresses are offset from the base exiting and re -running the program. numbers separated by a comma. address. In program and verify, any (T)EST This performs a test on the These addresses define the portion discrepancies between EPROM and EPROM, reporting whether or not it of the EPROM to be used and also computer memory will be reported. has been erased. the portion of computer internal Such discrepancies will be printed, (R)EAD, (P)ROGRAMME, (V)ERIFY memory into which data will be one per line, stopping after every 16 These commands cause the user to written for a read operation or from lines. Pressing return at this point be prompted for start and finish which data will be read for program will return to the *? prompt, addresses which should be entered or verify operations. The computer whereas pressing any other key will

50 ETI AUGUST 1983 PROJECT :EPROM Programmer

PARTS LIST 0

II RESISTORS (all 1-W 5% unless stated) PIN 1 II

g o R1, 11, 13 10k 0-o0 0..00 o o 0.--.00 R2, 12, 14 1k0 0-0 o 0.0 0 R3, 16 100k 0---o0 o-o 0 o-o 9 0 0 R4, 5 5k1 o ---o 0-0 R6 240R 0 0 0-0 0 0-0 o-o 001) OHO o 0 R7 15k 000 0-00 00 R8 680R 0.-0 0-0 OHO R9 OR22 wire wound 0 0.-0 0 O 0 R10 180R, 1W 00 0 00 0 0 R15 33k 0 000 000 0 0-00 RV1, 3 2k2 min horizontal preset 0-0 0--0 0.-C) RV2 4k7 min horiiontal preset I/0 +(16 x 0) = 0I/0 + (16 x 1) = 16 I/0 + (16 x 2) = 32I/O + (16 x 3) = 48I/O + (16 x 4) = 64 CAPACITORS Fig. 3 Setting the address offset by wire links. C1 1u 35 V axial electrolytic C2, 7, 8, 9, MODIFY will prompt for a single 10 100n ceramic corresponds to about 12000 C3 470u 35 V axial address, the contents of the base uW/cm2 at a distance of one inch, as electrolytic address offset by the value given used in most EPROM erasers. C4 4n7 polyester being displayed on the screen. The tube costs in the region of C5 10n ceramic Entering an X at this point will C6 100u 6V3 axial electrolytic £10 and will fit into an ordinary 15 " C10 10n ceramic return to the *? prompt leaving the fluorescent light fitting, it provides data in that location unchanged, the basis for a relatively inexpensive SEMICONDUCTORS whereas entering a two -figure IC1 74LS126 unit which could accommodate IC2 74LS245 hexadecimal number will cause the about ten ICs. IC3 74LSO4 relevant address to be updated with A few words of caution are IC4 74LS30 the data entered. appropriate at this point. Ultra -violet 105 74LS138 (H)ELP Lists all the commands radiation, and in particular IC6, 7, 8, 9 MC6821 (or similar) available and reminds the user of IC10 LM317M shortwave UV as emitted by the IC11 78S40 the currently selected EPROM type TUV 15 W, is harmful to both the Q1, 3, 4, 5, and base address. eyes and the skin. It is therefore 7 BC184L (E)XIT Causes the program to essential to build the tube into a Q2, 6, 8 BC214L terminate. D1, 2 0A91 light -tight cabinet, ideally with a In the above commands, any micro switch fitted under the lid to MISCELLANEOUS wrongly entered information will isolate the supply when opened, L1 34 turns 24 swg wire on result in self-explanatory error which will prevent UV light from RM6 pot core (AL = 250) messages. The one error message SKI, 2 0.1" pitch 22 -way male coming into contact with skin or molex connectors (or which, perhaps, requires a word of eyes. shorter ones made up to explanation is TYPE/RANGE EPROMs may also be erased by required length) INCOMPATIBLE. This error is a UV of longer wavelength (3000 A- SK3 28 pin zero insertion result of entering a start and finish force socket (or ordinary 4000 A) although longer exposure socket is console is used, address to any command which times will probably be required. see text) defines a range larger than the Since 'black light' tubes of the type SW1 two pole single throw capacity of the selected EPROM used for disco lighting emit at about switch (omit if using type. console) 3500 A and are more easily One 16 -way and one 80 -way DIL available than short-wave UV tubes, headers and sockets; edge connector (2 Erasing EPROMs it may be worthwhile experimenting x 32 -way A + B DIN Euro connector, male angled pins, for Tangerine) PCB, EPROMs are erased by with this type of light source. wire, etc. exposure to ultra -violet light through One final point on the topic of the transparent window on the top erasing EPROMs is that both of the package. Small commercially sunlight and ordinary fluorescent continue the programming or available erasing units with tubes emit some radiation in the verification. capacities of up to six chips cost 3000 A - 4000 A region with the (L)1ST, (M)ODIFY These commands typically in the f40-£50 region. If result that prolonged exposure to probably duplicate facilities the requirements for erasing these light sources will result in available in the computer monitor EPROMs are considered, it becomes erasure. For this reason it is but are included here to allow obvious that an erasing unit can be recommended that an opaque minimum changes to be made to constructed for considerably less adhesive label is used to cover the computer memory or data to be than the price of commercial windows of programmed EPROMs. checked without the need to exit equipment. The requirements stated Next month, we'll describe the from this package. LIST will request by EPROM manufacturers to erase software for the unit. ETI start and finish addresses and will such a device are a 20 to 30 minute BUYLINES list on the screen the addresses and exposure of 2357 A (253.7 nm) data of the portion of memory wavelength ultra -violet light at an There should be relatively few problems requested, offset from the base in obtaining components for this pro- intensity of 12000 uW/cm . The ject. The 0.22R resistor can be found in address. The listing will stop after Philips TUV 15 W tube emits UV at several suppliers' lists, including Wat- every 16 lines at which point the required wavelength and at an ford's. The RM6 potcore is available pressing return will exist to the *? intensity of 37 uW/cm2 at about one from RS Components. prompt, whereas pressing any other our PCB service - see page 77 for inch from the tube, the distance details. key will continue with the listing. metre from the tube, which

ETI AUGUST 1983 51 fUiVi y-etsP

Stopstrated assembly illu Instructionstogether , andfitting included ita descriptions. r ere %INPBRANDLEADING ELECTRONICS circuitquality iiadthHighest are NOW AVAILABLE IN KIT FORM componentsthroughout. used VOYAGER Car Drive Computer A most sophisticated accessory. Utilises a single chip mask programmed microprocessor incorporating a unique programme designed by EDA Sparkrite Ltd. Affords 12 functions centred on Fuel, Speed, Distance and Time. Visual and Audible alarms warning of Excess Speed, Frost/Ice, Lights -left -on. Facility to operate LOG and TRIP functions independently or synchronously Large 10mm high 400ft-L fluorescent display with auto intensity Unique speed and fuel transducers giving a programmed accuracy of + or -1%. Large LOG & TRIP memories. 2,000 miles. 180 gallons. 100 hours. Full Imperial and Metric calibrations. Over 300 components to assemble A real challenge for the electronics enthusiast' AT -80 Electronic Car Security System Arms doors, boot, bonnet and has security loop to protect fog/spot lamps, radio/tape, CB equipment Programmable personal code entry system Armed and disarmed from outside vehicle using a special magnetic key fob against a windscreen sensor pad adhered to the inside of the/screen' Fits all 12V neg earth vehicles Over 250 components to assemble SX1000 TX 1 002 Electronic Ignition Electronic Ignition Inductive Discharge Extended coil energy Contactless or contact triggered storage circuit Extended coil energy storage circuit Contact breaker driven Inductive Discharge Three position Three position changeover switch changeover switch Distributor Over 65 components to assemble triggerhead adaptors included Die cast Patented clip -to -coil fitting weatherproof case Clip -to -coil or remote Fits all12v neg. earth vehicles mounting facility Fits majority of 4 & 6 cyl. 12V. neg. earth vehicles Over 145

components to assemble.

TX2002 Electronic Ignition The ultimate system Switchable SX2000 contactless. Three position switch with Electronic Ignition Auxiliary back-up inductive circuit. The brandleading system Reactive Discharge. Combined capacitive on the market today and inductive. Extended coil energy storage Unique Reactive Discharge circuit. Magnetic contactless distributor trigger - Combined Inductive and head. Distributor triggerhead adaptors included. Capacitive Discharge Can also be triggered by existing contact breakers. Contact breaker drnien Die cast waterproof case with clip -to -coil fitting Fits Three position changeover switch majority of 4 and 6 cylinder 12v neg. earth vehicles. Over 130 components to assemble Over 150 components to assemble Patented clip -to -coil fitting Fits all 12v neg. earth vehicles All SPARKRITE products and designs are bully covered by one or more World Patents MAGIDICE Electronic Dic Not thetanauto but great fun family Total random selection SPECIAL OFFER Triggered by waving of hand Over dpsi ice and flashes during a 4 second tumble sequence "FREE" MAGIDICE KIT WITH Throw displayed for 10 seconds Auto display of last throw 1 second in 5 ALL ORDERS OVER £45.00 Muting and Off switch on base Hours of continuous use horn PP 7 battery Over 100 components to assemble MI In NM 11111 NM MI EN Tel (0922) 614791 Allow 28 days for delivery nO SPARKRITE 82 Bath Street. Walsall, West Midlands WS1 3DE England INC

SELF NAME ETI/8 ASSEMBLY KIT ADDRESS SX 1000 £12.95 SX 2000 £19.95 "le £22.95 :,119 TX 1002 I ENCLOSE CHEQUEISUROSTAL ORDERS FOR TX 2002 £32.95 Q% AT 80 £32.95 £. KIT REF 5;" VOYAGER £64.95 CHEQUE NO MAGIDICE £9.95 PRICES INC VAT.POSTAGE IS PACKING CUT OUT THE COUPON NOW MEI all MN EMIEMI NM 11111 INI1 electronics today international

How to order:BOOK indicate the books required by ticking the boxesSERVICE and send this page. together with your payment, to: ETI Book Service, Argus Specialist Publications Ltd, 145 Charing Cross Road, London WC2 OEE. Make cheques payable to ETI Book Service. Payment in sterling only please. All prices include P & P. Prices may be subject to change without notice.

BEGINNERS GUIDE Troubleshooting Microprocessors and Digital Logic Goodman £9.25 Getting Acquainted with your VIC 20 Hartnell £8.50 Beginner's Guide to Basic Programming Stephenson 535 Getting Acquainted with your ZX81 Hartnell £5.95 Beginner's Guide to Digital Electronics £5.35 Let your BBC Micro Teach you to program Hartnell £7.90 Beginner's Guide to Electronics £5.35 Programming your ZX Spectrum Hartnell £8.50 Beginner's Guide to Integrated Circuits £5.35 The ZX Spectrum Explored Hartnell £6.95 Beginner's Guide to Computers £5.35 How to Design, Build and Program your own working Computer System Beginner's Guide to Microprocessors £5.35 Haviland £9.30 BASIC Principles and Practice of Microprocessors Heffer £7.15 COOKBOOKS Hints and Tips for the ZX81 Howson £5.25 What to do when you get your hand on a Microcomputer Holtzman £9.95 Master IC Cookbook Hallmark £10.15 34 More Tested Ready to Run Game Programs in BASIC Horn £7.70 Microprocessor Cookbook M. Hordeski £7.70 Microcomputer Builders' Bible Johnson £12.40 IC Op Amp Cookbook Jung £1425 Digital Circuits and Microcomputers Johnson £14.55 PLL Synthesiser Cookbook H. Kinley £7.70 PASCAL for Students Kemp £7.20 Active Filter Cookbook Lancaster £13.40 The C - Programming Language Kernighan £1820 TV Typewriter Cookbook Lancaster £11.15 COBOL Jackson £925 CMOS Cookbook Lancaster £11.85 The 2)(81 Companion Maunder £9.50 TTL Cookbook Lancaster £10.95 Guide to Good Programming Practice Meek £6.40 Micro Cookbook Vol. 1 Lancaster £15.30 Principles of Interactive Computer Graphics Newman £13.95 BASIC Cookbook K. Tracton £6.00 Theory and Practice of Microprocessors Nicholas £11.35 MC6809 Cookbook C. Warren 025 Exploring the World of the Personal Computer Nilles £12.95 Microprocessor Circuits Vol. 1. Fundamentals and Microcontrollers Noll ELECTRONICS £9.80 Principles of Transistor Circuits Amos £8.50 Beginner's Guide to Microprocessors Parr £5.35 Design of Active Filters with experiments Berlin £11.30 Microcomputer Based Design Peatman £11.30 49 Easy to Build Electronic Projects Brown £6.00 Digital Hardware Design Peptman £9.80 Electronic Devices & Circuit Theory Boylestad £1320 BBC Micro Reavealed Ruston £9.45 How to build Electronic Kits Capel £3.55 Handbook of Advanced Robotics Safford £14.45 How to Design and build electronic instrumentation Carr £9.35 1001 Things to do with your own personal computer Sawusch £13.50 Introduction to Microcomputers Daglecs 020 Easy Programming for the ZX Spectrum Stewart £7.15 Electronic Components and Systems Dennis £15.00 Microprocessor Applications Handbook Stout £34.40 Principles of Electronic Instrumentation De Sa £11.40 Handbook of Microprocessor Design and Applications Stout £37.60 Giant Handbook of Computer Software £12.95 Programming the PET/CBM West £17.80 Giant Handbook of Electronic Circuits £17.35 An Introduction to Microcomputer Technology Williamson 01.20 Giant Handbook of Electronic Projects Computer Peripherals that you can build Wolfe £12.40 Electronic Logic Circuits Gibson £5.55 Microprocessors and Microcomputers for Engineering Students and Techni- Analysis and Design of Analogue Integrated Circuits Gray £3025 cians Wooland E7.10 Basic Electronics Grob £11.30 Lasers - The Light Fantastic Hallmark £7.70 REFERENCE BOOKS Introduction to Digital Electronics & Logic Joynson £5.25 Electronic Engineers' Handbook Fink £56.45 Electronic Testing and Fault Diagnosis Loveday £7.85 Electronic Designers' Handbook Giacoletto £59.55 Electronic Fault Diagnosis Loveday £625 Illustrated Dictionary of Microcomputer Technology Hord eski £8.45 Essential Electronics A -Z Guide Loveday £7.50 Handbook for Electronic Engineering Technicians Kauffman £27.50 Microelectronics Digital & Analogue circuits and systems Millman £12.70 Handbook of Electronic Calculators Kauffman £6.00 103 Projects for Electronics Experimenters Minis £8.30 Modern Electronic Circuit Reference Manual Marcus £44.00 VLSI System Design Muroga £34.10 International Transistor Selector Towers £10.70 Power FETs and their application Oxner £9.40 International Microprocessor Selector Towers £16.00 Practical Solid State Circuit Design Olesky £25.00 International Digital IC Selector Towers £10.95 Master Handbook of IC Circuits Powers £12.85 International Op Amp Linear IC Selector Towers £8.50 Electronic Drafting and Design Raskhodoff £22.15 Illustrated Dictionary of Electronics Turner £12.95 VOM - VTVM Handbook Risse £8.50 Video and Digital Electronic Displays Sherr £28.85 VIDEO Understanding Electronic Components Sinclair £7.50 £4.50 Electronic Fault Diagnosis Sinclair Servicing Home Video Cassette Recorders Hobbs £12.95 £17.35 Physics of Semiconductor Devices Sze Complete Handbook of Videocassette Recorders Kybett £925 132.00 Digital Circuits and Microprocessors Taub £12.95 £7.60 Theory and Servicing of Videocassette Recorders McGinty Active Filter Handbook £5.35 £1520 Beginner's Guide to Video Matthewson Designing with Tn. Integrated Circuits Texas £14.40 £15.20 Video Recording: Theory and Practice Robinson Transistor Circuit Design Texas £21.90 £12.95 Video Handbook Van Wezel Digital Systems: Principles and Applications Tocci Video Techniques White £12.95 Master Handbook of Telephones Traister £10.00 How to build Metal/Treasure Locators Traister £6.00 99 Fun to Make Electronic Projects Tymony £8.50 33 Electronic Music Projects you can build Winston £6.95

Ienclose cheque/postal order for & MICROCOMPUTERS Please send me the books indicated. COMPUTERS Prices include postage and packing BASIC Computer Games Ahl £6.35 I wish to pay by Access/Barclaycard. Please debit my account. From BASIC to PASCAL Anderson £9.95 Mastering Machine Code on your ZX81 T. Baker £725 UNIX - The Book Banaham £8.75 51212141I I IIIIII I I I 1 Z80 Microcomputer Handbook Barden £10.95 Microcomputer Maths Barden £11.90 Digital Computer Fundamentals Barter £9.90 1 1-1 1 1 1 1 1 1 1 1 Visicalc Book. APPLE Edition Bell £15.55 41912191 Visicalc Book. ATARI Edition Bell E15.55 Introduction to Microprocessors Brunner £23.00 Signed Programming your APPLE II Computer Bryan £9.25 Microprocessor Interfacing Carr £7.70 Name Microcomputer Interlacing Handbook A/D & D/A Carr £9.50 Musical Applications of Microprocessors Chamberlain £28.5 Address 30 Computer Programs for the Home Owner in BASIC D. Chance £925 Microcomputers Dirkson £930 APPLE Personal Computer for Beginners Dunn £9.50 Microcomputers/Microcomputers - An Intro Gioone £11.80

ETI AUGUST 1983 is of greater interest than economy becauseof government controls, hence it was called the PED., (Pollu- tion Elimination Device). Out of 400 READ/WRITE devices tested by the American En- vironmental Protection Agency, the Hyconomiser weakening effect more or less com- PED came out first.To the British pensating for wear of the carburettor motorist economy is the more impor- Dear Sir, metering orifice. For the car in ques- tantfactor, hence the change of I have been a more or less regular tion a new carburettor, or even simp- name. There is nothing sinister in reader of ETI since its inception and I lyreplacing the metering needle that. think generally you do a pretty good costing about f3, would undoubtedly Mr Bywater scorns the idea that job; however, you have now made a have shown similar,if not better sonic waves produced by plastic balls serious error by recommending a gains. In any event the only way to test can break up fuel droplets. Perhaps product which you are not really a device such as this is under careful- he would likewise scorn the sugges- qualified to pronounce upon. I refer ly controlled conditions and even tion that a piece of flapping paper to the feature on the Hyconomiser in then so many variables can be involv- could permanently damage scores of your June issue. ed that results are likely to have a human eardrums at a range of many If,instead of questioning the spread of 10% or so. yards, yet if he would visit his nearest garages involvedinsellingthe As for the claim that fuel droplets disco he will find loudspeaker cones device, who you must admit have a are broken up with sonic waves ' doing just that.Itis the power ac- vested interest, you had spoken to a generated by three pulsating balls, if tuating the medium, not the 'medium recognised authority on the subject, I you believe that I would also expect itself thatisimportant. Here, the am sure you would have been told you to look for fairies at the bottom of power is provided by the vacuum not to waste your time on it, and cer- your garden. For sonic waves to generated by the engine intake or in- tainly not to give any recommenda- pulverise fuel droplets it is necessary duction stroke. If this has sufficient tion.Talking to garage mechanics fora large amount of energy to be ex- power to atomise fuel from the car- about engine fuelling and exhaust pended in shearing the mixture and burettor in the first place why should even then economy gains are unlike- it be insufficient to complete the job emission technology (a subject not by means of the Hyconomiser? far behind aerospace and electronics ly to exceed 10%. for expenditure and complexity) is The claim that the device main- The balls are in fact tuned to tainstheair/fuelratiocloseto resonance, and when resonating any rather like asking an electrician to physical object is capable of high comment on the latest stoichiometric is quite unfounded. If you can find out how this is achieved amplitude oscillation which can even microprocessor. be destructive,as any student of For many years,includinga pleased let me know - nobody has been able to explain to me how it can mechanical stress engineering would number as a senior development know. The effect has in fact been engineerat Jaguar Cars, fuel happen. Finally, if a device such as this observed in tests carried out by a economy had been a specialist sub- motormanufacturer. An intake ject of mine and devices such as the was able to offer the improvements claimed,the motor manufacturers manifoldwithtransparentquartz Hyconomiser invariably come my window was assembled to a produc- way for appraisal.infact, two or would be already using it rather than running multi -million pound retool- tion engine. With normal running, three years ago this device was being drops of fuel could be seen coursing marketed as the PED with a rather dif- ing programmes to obtain relatively modest gains, and electronic engine the over the inside surfaces to be ferent story behind it.I enclose a ejected with the exhaust, but when copy of the advertising material rele- management systems (surely a more Hyconomiser was switched in by a vant to that incarnation which you appropriatesubjectforyou to control valve,the drops instantly will see employs the same diagram becomeinvolvedin)would be vaporised into a mist. Special rapid - you reproduced. In an attempt to win unnecessary. exposure photographic techniques me over I was visited by the alleged If you wish to maintain the high and precision measurements reveal- inventor of the device, acertain reputation of your magazine I think ed the particle size to be in the region Canadian called Andrew MacGuire, you would be well advised to print a of eight microns. and was presentedwith anim- retraction on the subject as soon as The motor manufacturer, (a well- pressively thick report, produced in possible. known name that I cannot reveal at the USA, purporting to show how ef- Yours faithfully present) will infact be using the fective it was. To the uninitiated it Roger Bywater Hyconomiser infuture production was most convincing but on close ex- Roger Bywater Engineering Ltd models. It has not been used before amination most of -the tests were bas- Stockport because car design and planning is ed on unrealistic baseline figures, in Cheshire usually at least three years ahead of one case an exhaust CO level of 8% current production. Other manufac- (a vastly over -rich condition) was us- The author replies: turers are actively considering it. ed as a basis for comparison. I still Much more about the Hyconomiser, Mr Bywater's assertion that my have a copy of the report if you its inventor and history was known to economy figures were due to a leaner should wish to see it. me before undertaking the review, mixture produced by bleeding air Whilstitmay bethatyour but my brief from the editor was to past the carburettor can be refuted reviewer obtained a measurable im- confine the report to 1,000 words so on two counts. First, the carburettor provement after fitting the device, much had to be omitted. The device mixture setting must be made slightly any air bleed into the inlet manifold reduces pollution as well as effects richer before fitting the Hyconomiser (whichinessenceis whatthe fuel economy. In Canada where it to cornpense for the extra air thus Hyconomiser is) will have a mixture was first produced, pollution control restoring the correct air/fuel ratio. Se - 54 ETI AUGUST 1983 FEATURE

cond, when the device went off tune Compact Disc to music reproduction to be testing for reasons described in my review, pure tones, but why not simply com- theconsumptionclimbedtoits Dear Sir, pare 'scope photos of microphone formerfigure.On re -tuning,the The article in your May '83 issue signals at the recording studio with economy returned. According to Mr concerning recommended high - quality turntable systems was punc- the ultimate, played -back signal from Bywater tuning should have made analogue and digital discs? Could no difference as air was still passing tuated by a small section on the new Compact Disc format. As the author such a test be arranged or would through. He alleges that the air bleed vested interests prevent it? merely neutralizes wear in the fuel observes,'inabout ayear' CD An article devoted to bringing needle and orifice of the carburettor, players will be altogether affordable, more rigour into Hi-Fi assessment probably considerably cheaper than and that a replacement would have along theselines would certainly the same result. However, the device specialist analogue turntables and thereforelikelytooust them on have my fullest attention, and should has been fitted to brand new cars not be irrelevant to the aims of your with notable economy grounds of both performance and value. At that time, second hand (one magazine, since it would not labour improvements. the subject of the Hi-Fi market or the The 8% CO emission figure he year old), once -expensive analogue players would presumably be present state of the manufactured art, complains of does indeed represent but would deal rather with an abnormally rich mixture, some 9:1 demoted to duties such as door - stopping or pot -throwing in view of 'transduction'. air/fuelratio.However,thiswas Yet more relevant, of general in- merely the starting point of a graph their likely marketability.Iwould therefore query the advisability of terest and, as yet, unreported (to my plot which shows the comparative knowledge) would be an investiga- CO emissions with and without the any recommendation to buy high quality analogue disc equipment. tion of the digital disc format and its Hyconomiser, over a wide range of protocol; how are the discs manufac- mixtures from 9:1 to 20:1. You have Of course, my premis in such a sweeping statement is that CD will be tured, what is this error correction to start a plot somewhere, usually it is business? Would it be at all possible best to do so outside of the area of in- a vastly superior format, bringing me to produce an alternative erasible tersst so that a complete picture is onto my second beef; why so little and programmable, ideally compati- space for such an important presented. ble, optical recording system, As to the question as to how the breakthrough, about which plentiful information has been distributed in perhaps by populating a disc fully stoichiometric (optimum) 14.6:1 ratio with reflective logic cells but posi- is maintained by the device, this is advance certainlyto many Hi -F! tioning an optically switchable win- done firstly by improved atomisation magazines who have seenfitto dow in front of each? and distribution of fuel.Thus the publish reports on the subject? Now I Presumably it is the variability in anomalies of lean and rich areas in would not expect you to give a high performance of D -to -A priority to reporting on Hi-Fi matters convertors different cylinders and parts thereof thataccounts for the present are avoided. Secondly, the lowest normally, though surely the presence variability in CD player performance. ball in the Hyconomiser seats against of an audio article anyway might Would it be conceivably possible to its exit orifice. This expands and con- have been used to better advantage. I would certainly be interested to delay the mapping to as late a stage tracts according to the vacuum in the as possible, having a (perhaps in- inlet manifold and so controls the know what levels of fidelity are claim- ed for the pressing and then optimal tegral) D -to -A power output stage, or airflow. Thereby the amount of air, is the process of amplification (and hencemixture ratio, varies in reading of vinyl discs so that these could be compared with the plentiful transduction) bestleftto conven- response to engine speed and throttle tional analogue techniques? An ac- setting, so compensating for the mix- informationavailable fordigital format. quaintance has described to me his ture vagarities produced by the car- attempts to make a digital switching burettor under differing conditions. The world of audio performance amplifier. (A -to -D -to -A), but, Garages who fit the assessment has become altogether clutteredwithhighlysubjective presumably digital speakers could Hyconomiser may indeed,as Mr not successfully operate composed of Bywater says, have a vested interest, judgement. Hi-Fi magazines persist an array of switching drivers, (one but not of the sort he insinuates. All in, what seems to me, the odious twice the size of the next) whilst the thoseIcontacted were reputable convention of allowing poets with 'golden ears' to subjectively assess idea of linear stepper motors attach- main -agent establishments with large edtoconventionaldiaphragm(s) factory -trained staffs and the latest in nebulous qualities, transferring little would seem unrealistic. elecronictuninganddiagnostic hard information to the reader. For Any ideas? equipment. Their vested interest is in reference, it would be interesting to Yours faithfully their reputation which would soon see, published alongside a reviewer's Mr P.E. Cox be in tatters if they fitted rubbish that observations, the results of a Derby didn't work. As the proprietor of a thorough hearing test performed on fuel injection and economy develop- him at a relevant time. Could con- ment company, may I suggest that HE trolled levels of distortion, on iden- Mr Cox raises far too many points is the one that has a vested interest in tical pieces of recorded music, be us- forusto answerinthe space knocking the Hyconomiser! ed to testa 'golden auditor's' true available! Suffice to say that CD will Vivian Capel. calibration? not make analogue players obsolte We doubt whether we have heard Personally,I find itdifficult to because there will still be a lot of the last of this topic. For those of give more credence to the doubtless analogue discs around for many youstillsending us missives by limited -bandwidth response of age- years to come. We'll obviously be various means, the Hyconomiser is ing reviewers than laboratory test reporting further on CD inthe now made under licence by: Atwell equipment. Admittedly, standards of future. Construction Ltd, Station Road, Wr- distortion measurement are confus- ington, Avon, Tel: Bristol 719441. ing, and it is not sufficiently relevant ETI

ETI AUGUST 1983 55 MASTER ELECTRONICS NOW! The PRACTICAL way!

This new style course will enable You will do the following: anyone to have a real understanding Build a.modern oscilloscope of electronics by a modern, practical and visual method. No previous Recognise and handle current electronic knowledge is required, no maths, and components an absolute minimum of theory. Read,draw and understand circuit diagrams You learn the practical way in easy*Carry out 40 experiments on basic steps mastering all the essentials of your hobby or to start or further a electronic circuits used in modern career in electronics or as a self- equipment employed servicing engineer. Build and use digital electronic circuits All the training can be carried out in and current solid state 'chips' the comfort of your own home and at your own pace. A tutor is available toLearn how to test and service every type whom you can write personally at any of electronic device used in industry and time, for advice or help during your commerce today. Servicing of radio, T.V., work. A Certificate is given at the end Hi-Fi and microprocessor/computer of every course. equipment. Newat?NewCareer?NewHobby?GetintoElectronicsNow! II Please send your brochure without any obligation to I am interested in: ETI/8/83

COLOUR BROCHURENAME I I COURSE IN ELECTRONICS I as described above ADDRESS I RADIO AMATEUR LICENCE I OTHER SUBJECTS I I I MICROPROCESSORS

I _J LOGIC COURSE BLOCK CAPS PLEASE I LiairariatOna 1 Rad 0 ee Me &MACSSchool Reading,Berks.RG1 1BR

BUILD A BETTER AMPLIFIER!

How can you own a top class HIFI amplifier, of comparable standard to Nelms, Meridians, Quads etc., for an outlay of less than £250? - Simple! Built It yourself - with a Crimson kit. It is not necessary to spend a small fortune to obtain true Hifi performance. Crimson Kits offer all the features and sound quality of themost esoteric amplifiers available and their ease of assembly ensures that they work first time and continue to do so. Not only do Crimson Kits offer outstanding value, but they also have the flexibility to adapt to any users needs. All the P.C.B.'s are ready assembled and tested (they are not"pot- ted" as we believe disposable modules are rather extravagant!) therefore constructing a kit is pleasurable in itself and, once built, will give years of untroubled service. So, whether you use a simple record player or a compact disc, you can be sure to get the most from yoursystem. E.T.I. said, in their review of the CK1010/1100: "I can say no more than that for 250 it is a bargain and one that will become thereference point for kit amplifiers from now on." Need we say more? PRICES * Summer Special Offer: Buy a CK1010 and any CK power amplifier and get an MC2K board free!!* * CK1010 - STEREO PRE -AMPLIFIER (moving magnet, tape, tuner input) takes power from any CK power amp or separate p.s.u. type P.S.K. £92.00 CK1040 - STEREO POWER -AMPLIFIER 40 watts R.M.S./Chanel £121.00 CK1080 - STEREO POWER -AMPLIFIER 80 watts R.M.S./Chanel £134.00 CK1100 - STEREO POWER -AMPLIFIER 100 watts R.M.S./Chanel £151.00 MC2K - Moving coil add on kit for CK1010 £25.00 P.S.K. - power supply for CK1010 (if not used with a CK power amp) £20.00 CRIMSON also supply power amp, pre amp and electronic crossover modules, power supplies and hardware - too much to list here - but on receipt of an S.A.E. we will be happy to supply full details. TO ORDER Send C.W.O. or quote your access card no (phone orders accepted) Crimson Products are also available from Bradley Marshall Ltd, 325 Edgeware Road, London. * Offer closes 31st July 1983 (Return this ad with your order) CE5CRIMSON ELEKTRIK STOKE MANUFACTURERS OF PROFESSIONAL, DOMESTIC & INDUSTRIAL AMPLIFICATION PHOENIX WORKS, 500 KING STREET, LONGTON, STOKE-ON-TRENT, STAFFORDSHIRE. ST2 1EZ w 0782 330520

56 ETI AUGUST 1983 *Gold service available 21 days manufacture for urgent TOROIDALS deliveries. The toroidal transformer is now accepted as the standard in*Orders despatched industry, overtaking the obsolete laminated type. Industry has within 7 days of been quick to recognise the advantages toroidals offer in size, receipt for single or weight, lower radiated field and, thanks to I.L.P., PRICE. small quantity orders. Our large standard range is complemented by our SPECIAL DESIGN section which can offer a prototype service within 7 DAYS together with a short lead time on quantity orders which can be*5 year no quibble programmed to your requirements with no price penalty. guarantee.

SERIES SECONDARY RMS SERIES SECONDARY RMS - SERIES SECONDARY - RMS TYPE PRICE TYPE PRICE TYPE PRICE No Volts Current No Volts Current No Volts Current 0 ltk.-.I. %4 .ON 14°4\ 120 VA 4x010 6+6 10.00 300 VA 7x013 15+15 10.00 90 x 40mm 4x011 9+9 6.66 110 x 50mm 7x014 18+18 8.33 15 VA Ox010 6+6 1.25 1.2Kg 4x012 12+12 5.00 2.6Kg 7x015 22+22 6.82 Reglullawtoion 44:004134 62 x 34mm Ox011 9+9 0.83 15+15 43..3003 Regulation6wo 77:00167 2350+4_2350 56..0000 0.35Kg 0x012 12+12 0.63 £7.42 £10.88 £5.12Regulation 0x013 15+15 0.50 4x015 22+22 2.72 + p & p £1.72 7x018 35+35 4.28 + 0 8 p E2.05 19% 0x014 18+18 0.42 +p 8 p£0.78 4x016 25+25 2.40 + VAT E1 .37 7x026 40+40 3.75 + VAT £1.94 0x015 22+22 0.34 + VAT 00.89 4x017 30+30 2.00 TOTAL 010.51 7x025 45+45 3.33 TOTAL £14.87 0x016 25+25 0.30 TOTAL E6.79 4x018 35+35 1.71 7x033 50+50 3.00 0x017 30+30 0.25 4x028 110 1.09 7x028 110 2.72 I 4x029 220 0.54 7x029 220 1.36 (encased in ABS plastic) 4x030 240 0.50 7x030 240 1.25

30 VA 1x010 6+6 2.50 70 x 30mm 1x011 9+9 1.".66 160 VA 5x011 9+9 8.89 500 VA 8x016 25+25 10.00 0.45Kg 1x012 12+12 1.25 £5.49 110 x 40mm5x012 12+12 6.66 140 x 60mm 8x017 30+30 8.33 Regulation1x013 15+15 1.00 +08p£1.10 1.8Kg 5x013 15+15 5.33 4Kg 8x018 35+35' 18% 1x014 18+18 0.83 + VAT E0.99 Regulation5x014 18+18 4.44 Regulation8x026 40+40 6.257.14 £14.38 1x015 22+22 0.68 TOTAL E7.58 8% 5x015 22+22 3.63 £8.43 4% 8x025 45+45 5.55 + p 8 p E2.40 1x016 25+25 0.60 5x016 25+25 3.20 + p 8 p £1 .72 8x033 50+50 5.00 + VAT E2.52 1x017 30+30 0.50 5x017 30+30 2.66 + VAT E1.52 8x042 55+55 4.54 TOTAL E19.30 5x018 35+35 2.28 TOTAL E11.67 8x028 110 4.54 50 VA 2x010 6+6 4.16 5x026 40+40 2.00 8x029 220 2.27 80 x 35mm2x011 9+9 2.77 5x028 110 1.45 8x030 240 2.08 0.9Kg 2x012 12+12 2.08 5x029 220 0.72 Regulation2x013 15+15 1.66 5x030 240 0.66 13% 2x014 18+18 1.38 £6.13 2x015 22+22 1.13 + 0 8 0 01.35 625 VA 90017 30+30 10.41 2x016 25+25 1.00 + VAT E1.12 140 x 75mm 9018 35+35 8.92 2x017 30+30 0.83 TOTAL E8.60 225 VA 6x012 12+12 9.38 2x028 110 0.45 110 x 45mm6x013 15+15 7.50 Reg6uKlagtion 69xx°02265 4405++4450 6.941 £17.12 2x029 220 0.22 2.2Kg 6x014 18+18 6.25 4% 9x033 50+50 6.25 + p 8 p E2.55 2x030 240 0.20 Regulation 6x015 22+22 5.11 9x042 55+55 5.68 + VAT £2.95 7% 6x0.16 25+25 4.50 £9.81 9x028 110 5.68 TOTAL 022.62 80 VA 3x010 6+6 6.64 6x017 30+30 3.75 + p8 p02.05 9x029 220 2.84 90 x 30mm3x011 9+9 4.44 6x018 35+35 3.21 + VAT £1.78 9x030 240 2.60 1Kg 3x012 12+12 6x026 £13.64 Regulation3413 15+15 1332.66 £6.66 '6025 45+45 2.50 12% 3x014 18+18 2.22 + p 8 p E1.72 6x033 50+50 2.25 3x015 22+22 1.81 + VAT Et .26 6x028 110 2.04 3x016 25+25 1.60 TOTAL £9.64 6029 220 1.02 ALSO AVAILABLE 3x017 30+30 1.33 6x030 240 0.93 Sizes up to and including 5KVA are 3x028 110 0.72 3x029 220 0.36 manufactured to order. 30030 240 0.33 The benefits of ILP toroidal transformers For mail orde please make your crossed cheques or postal ILP toroidal transformers are only half the weight and height of their laminated orders payable toI LP Electronics Ltd. Barclaycard/Access equivalents. and are available with 110y, 220V or 240V primaries coded as follows: welcome. Trade orders standard terms. IMPORTANT: Regulation - All voltages quoted are FULL LOAD. Please add regulation figure to secondary Post to ILP Electronics Ltd. Graham Bell House. Roper Close. voltage to obtain oft load voltage. Canterbury CT2 7EP Kent. England. Telephone (0227) 54778 Telex 965780 For 110V primary insert "0" in place of "X" in type number.

For 220V primary (Europe) insert "1" in place of "X" in type number. Ia division of For 240V primary (UK) insert "2" in place of "X" in type number. ILP Electronics Lid) Also available at Electrovalue,Maplin,Technomatic and Barrie Electronics. 0TRANSFORMERS

LOW COST PROFESSIONAL TEST INSTRUMENTS

FREQUENCY METERS ANALOGUE MULTIMETERS I1bEN352111nlin elemic DIGITAL MULTIMETERS Hand Held FUNCTION GENERATOR OSCILLOSCOPES Analogue and POWER SUPPLIES Digital LOGIC PROBE SCOPE PROBES Multimeters eieetto RSI* sabtronics C3C Write or phone for illustrated ".A*1 test instrument catalogue and price FREQUENCY METERS 16 Models list Black Star Ltd. 100MHz, 600MHz, and 1GHzModels from £18.75 9A, Crown Street Mack Star from £67 St. Ives, Huntingdon =LI Cambs. PE17 4EB Tel: (0480) 62440 Telex 32339

ETI AUGUST 1983 57 FEATURE TECH TIPS

FROM DO KEYBOARD D1 D2 Keyboard 03 '5V D4 R1 Alphanumeric Lock 10k

+C1 10 Switch 4u7 IT 16V D5 IC2d G. Franklin, Mid Glamorgan PR IC2c D 0 1C3 51C2b NOTE: if your ASCII keyboard is like mine, ICI IS 74LS30 CLK IC2 IS 74LS132 then you too will have become tired LED1 IC3 IS 74LS74 of having to press 'SHIFT' for capital PBI I 0 +5V R4 fi letters. SHIFT lock is useless because CLR 220R you have to'unlock'to use the +5V numbers. This circuit does away with R3 this problem by providing you with 1k0 yet another key to press. This is the 'ALPHA LOCK' switch. to z ($7A). The circuit cheats slightly, with data bit 6 being 'HIGH' will If you study the ASCII codes you by altering codes $60 to $7Fin- make D5' a'LOW', thus shifting a will find that to change 'a' into 'A' re- clusive, the only problem with this is $60 code down to $40 (unless of that is quires only the removal of the logic $7F theASCIIcodefor course it was the 'DELETE' key that 'DELETE'.IC1deals withthis,by was pressed). The LED will come on '1' on the data bit 5 line (of the 8 bit detecting the $7F code and making bus fromthekeyboardtoyour to show when the ALPHA mode is sure D5 stays at a logic 1 computer). via the selected. To insert this circuit into NAND gate at the end of the circuit. your keyboard, itis only necessary e.g.:- One quarter of the 74LS132 is us- for D5 to come via this circuit, D5' a A ed to give a degree of switch bounce then continuing in ASCII code $61 $41 its place to the in binary:- to Si. Every time S1 is pressed, the Q computer, the other data lines just 0110 0001 0100 0001 output of the latch (IC 3) will change, We require to alter the complete connect to the circuit. The only other' R1 and Cl ensure that on power-up requirementisthat youinserta alphabet, this stretches from a ($61) the output is at a logic 1. This, along switch somewhere.

I 470n 3 Controller For RED 14 Model Traffic Lights Mo. 1111) CLK IC2 AMBER IMO 3' 13 GREEN INHIBIT P. Bailey, Glasgow 4'2 10- RESET The circuit shownwas devised to 15 control LED traffic lights at a road 14 junction in a model railway layout, CLK 3 LIGHT 1 RT for added realism.IC2, a decade 470k 2 LIGHT 2 counter,togetherwithIC3a and IC3b, generates the normal traffic IC1d IC4 light sequence continuously at a rate IC5a C5h IC5c IC5d IC7a IC7b 13 INHIBIT'2't-, determined by the oscillator formed 2- RESET around ICla and IC1b. A monostable 15 formed by IC1c and ICld is triggered by a '1' on the 'GREEN' output, and NOTE: IC1,6 ARE 4001 inhibits IC2 for a period set by Cr and IC2 ,4 ARE 4017 1k0 >Ik0 >1k0 1k0 1k0 IC3 IS 4071 RT, thus causing the green light to be IC5,7 ARE 4081 LED 1.6 ARE MINIATURE LEDs LIGHT 1 LIGHT 2 on for a longer period than the LED1,4 ARE RED r-- I- others. LED2,5 ARE YELLOW ILED1 LED2 LED3 I I LED4 LED5 LED6 LED36 ARE GREEN .0' ae IC4 selects either LIGHT 1or Ire II LIGHT 2 to display the sequence, L -- J L_ I thesebeingselectedalternately. thisisnot required, IC4 could be When one_ lightis changing or at replaced with a single flip-flop stage green, the other is held at red. (eg a 4013), set to toggle, LIGHT 1 lightscan be constructedfrom The controller is easily expanded and LIGHT 2 being connected to the miniature' LEDs and empty pen refill to operate more than two lights by Q and Q outputs respectively. With a tubes. using further outputs from IC4, but if little ingenuity, realistic -looking traffic ETI 58 ETI AUGUST 1983 ELECTRONIC COMPONENTS AND TEST EQUIPMENT 35. HIGH BRIDGE. NEWCASTLE ITKf1443Ros. UPON TYNE NE1 lEWTEL. 0632 326729 MULTIMETERS THANDAR TM351 FREQUENCY COUNTERS Bench/portable 31/2 -digit 0.5" LCD 0.1% THANDAR TF200 10Hz to 200 MHz basic accuracy 29 ranges. Battery life Bench/portable 8 -digit Liquid Crystal Dis- typically 2000 hrs Complete with batteries & play. Frequency range 10 Hz - 200 MHz test leads. £113.85. Resolution better than 1 ppm Sensitivity Accessories. Carrying case £8.84. Universal typically 10mVrms Time base accuracy 0.3 test lead set £12.65. Service Manual £3.00. ppm. Battery life 200 hours Frequency, time average period, totalize & reset; 2 ranges. THAN TM353 5 gate times; external clock facility Complete Bench/portable 31/2 -digit 0.5" LCD 0.25% with batteries. £188.75. basic accuracy 26 ranges Battery life typically 3000 hrs Complete with batteries & THANDAR TF040 10 Hz to 40 MHz test leads £88.25. Accessories as TM351. Bench/portable 8 -digit Liquid Crystal Dis- play. Frequency range 10 Hz - 40 MHz THANDAR TM354 Resolution 1 Hz. Sensitivity 40 mV rms. Pocket size. 31/2 -digit 0.5" LCD, 0.75% Timebase accuracy 0.5 ppm Battery life 80 basic accuracy. 14 ranges Battery life 200 hours. Frequency, totalize & reset: 2 gate Ms £45.94. Carrying case £3.45. Universal times Complete with batteries. £128.50. test lead set £12.85. Service Manual £3.00. ACCESSORIES FOR TF200 8 TF040 AC THANDAR TM451 adaptor £7.99, Carrying case £8.48, X1 Probe Bench/portable 41/2 -digit 0.4" LCD 0.03% £8.05, X10 Probe £9.20, Service manual basic accuracy Full auto -ranging or manual Sample hold Audible continuity test £3.00. TP800 prescaier £51.75. TP1000 pre - Complete with battery and leads £171.35. scaler £74.75. AC Adaptor £7.99, Universal test leads £12.65. THANDAR PFM200A 20 Hz to 200 MHz Service Manual £3.00. Pocket size 8 -digit LED display Fre- OSCILLOSCOPE quency range 20 Hz - 200 MHz. Resolution THANDAR SC110A 0.1 Hz. Sensitivity typically 10 mV rms. Timebase Bench/portable Low power 10 MHz accuracy 2 ppm Battery life 10 hours. Fre- bandwidth 10mV sensitivity £1 71.35. Carry- qucny; 2 ranges, 4 gate times BNC input soc- ing case £8.34. AC Adaptor £7.99. Recharg- kets £77.82. Accessories. Carrying case £3.45, able battery pack £12.85. X1 probe £8.05. X10 AC adaptor £7.99, X1 probe £8.05, X10 probe MEP probe £8.20, X1 X10 Switched probe £10.93. £9.20, Service Manual £3.00. Sprung hook trimmer pack £2.88. Manual £3.00. Full spec available on all instruments, just phone GENERATORS or write: THANDAR TG100 Function 1 Hz to 100 KHZ £90.85 Schools, colleges. universities supplied on TG102 Function 0.2 Hz to 2 MHz £188.75 IMO official orders. TG105 Pulse 5 Hz to 5 MHz £97.75 VISA Prices include VAT. Please add £1.00 postage to rxmosso orders under £20.00.

Accurate Digital Multimetersat

NEW ANALOGUE METER WITH CONTINUITY Exceptional Prices BUZZER AND BATTERY SCALE

28 RANGES, EACH WITH FULL OVERLOAD PROTECTION. NEW HM 102 BZ SPECI FICATION DC Voltage: 0-25, 1, 2.5, 10, 25, 100, 250, 1000 SPECIFICATION MODELS volts 20,000 ohms/volt. 6010 & 7030 AC Voltage: 0-10, 25, 100, 250, 1000 volts 10,000 ohms/volt. 10 amp AC/DC Decibels: -20 to +22dB Battery: Single 9V drycell. Life: 200 hrs DC Current: 0-50, 500pA, 0-5, 50, 500mA Dimensions: 170 x 89 x 38mm. Ohmmeter: 0-6 Megohms in 4 ranges. Weight: 400g inc. battery. 30 ohms Centre Scale Mode Select: Push Button. Power Supply: One 1.5V size 'A' battery lincl) AC DC Current: 200i.tA to 10A Size & Weight: 135 x 91 x 39mm, 280gr. AC Voltage: 200mV to 750V DC Voltage: 200mV to 1000V

Resistance: 200E2 to 20M17

Input Impedance: 10MQ

Display: 3% Digit 13mm LCD HM 101 POCKET SIZE MULTIMETER Woad Protection: All ranges SPECIFICATION DC & AC Voltage: 0-10, 50, 250, 1000 volts, 2000 ohms/volts " Decibels: -10 to +22dB OTHER FEATURES: Auto polarity, DC Current: 0.100mA auto zero, battery low indicator, ABS Ohmmeter: 0-1 Megohm in 2 ranges, plastic case with tilt stand, battery and 60 ohms Centre Scale test leads included, optional carrying Power Supply: One 1.5V size 'A' battery (ine')

case. Size & Weight: 90 x 60 x 29mm, 92gr. incl. battery battery Quantity discount for trade on application. £5.50 Add 15% to your order for VAT. P&P is free of charge. Payment by Cheque with Order. Access & Barclaycard accepted.

ess -ARMON ELECTRONICS LTD. Cottrell House.53-63 Wembley HillRoad. Wembley, Middlesex HA9 8BH, England Telephone 01-902 4321( 3 lines I TELEX No 923985

ETI AUGUST 1983 59 hi! performance hi! competitive hi! THE POWERFET (pantechnic) SPECIALISTS . FULL HOUSE OEM USERS Pantechnic present the most adaptable high powered amplifier ever. OF MULTIMETERS FET SYST E M AMP TRIOBench Models DL 705, 706, 720 and DF 760 Features: t. HIGH POWER. 1.2KW (single ended). 31/2 and 4% digit LED LOW VOLUME. 1/15 Cubic foot inc. Heat Sink. Rugged and Reliable VERSATILE. Delivers more than 1 KW into 1/2 to 8 ohms. 2 YEAR GUARANTEE OR 2 x 600W into 2 to 8 Simple Operation - OR 4 x 300W into 2 to 4 (200W into 1-2 ) Auto Ranging 1 x 600W into 2 to 82 Mains or Battery a OR1 x 300W into 2 to 4E2 7 Digit Frequency Counter 1 x 150W into 4 to 852 Resolutions 1 and 0.1 mV Etc. Etc. DCV, ACV, DCA, ACA and Having been closely involved in a wide varietyof OEM applicationsof Ohms their amp boards, Pantechnic became aware of numerous imple- Basic accuracy 0.8, 0.25, 0.1 and 0.05% mentation problems often left untackled by other amp board manu- Prices from just over £100 includes FREE Batteries, facturers.These problems specifically of size and thermal efficiency Hand Book and Test Leads became particularly aggravated at high powers and considerably Hand Held Models HM101 and 102 Series, lengthened OEMproduct development time. HC HC 601, 703, 6010 and 7030. By including thermal design in the totalityof board design it has been 31/2 digit LCD and possible to reduce the size of the electronics, and increase the Analogue efficiency of the transistor to heatskink thermal circuit. The com- Colour coded front bined effect of this has been to dramatically increase the volumetric panel and edge switches efficiency of the amplifier/heatsink assembly. The SYSTEM Amp High impact ABS with offers 1.2KW of power in a space of 102mm x 102mm x 77mm, Tilt stand excluding PSU and Fan. Safety features meets The basis of this considerable advance is the PANTECH 74 Heat UL 1244 Exchanger,newly designedandmanufacturedbyus.By Basic accuracy 0.6 and 0.2% eliminating the laminar airflow found in conventional, extruded heat Full Range of DCV, ACV, sinks, heat transfer to the environment is greatly enhanced. DCmA, ACmA and Ohms The flexibility of the 1.2 KW amp stems from its division into 4 poten- Audio Continuity Tone tially separate amplifiers of 300W each (down rateable with cost sav- Plus 10A capability. ings to 150W.)These can be paralleled, increasing current capability

Switched HI and LO ohms or seriesed (bridged in pairs) doubling voltage capability. In conse- FREE Battery, Manual and Test Leads quence a large variety of amplifier/load strategies can be imple- Analogue from approx £6- Digital from approx £34 mented. As ever Pantechnic offer a full range of customising options includ- NEW MAIN, 2H, 3E and 50. M2011, 2012, 2030, ing DC coupling, ultra high slew etc. Contact Phil Rimmer on01-800 BBCAIETRAWATT 2031 and 2032. Unigor 3N. 6667 with your particular application problem. Digital and Analog -Hand P.S. Specs, as ever, are exemplary. Held and Bench Huge LCDs -Many Safety OTHER POWERFET AMPLIFIER MODULES Features Model Price Rang* Dyn-loads Notes Black, Rugged and Reliable (Finis) 1 Year Guarantee *PFA100 20.65 50-150W 4 r2, 8 Physically small (32 x 78 x 31/2 and 41/2 Digits 108mm) Variable Viewing Angle - *PFA200 27.35 100-300W 4 u, 8 v High watts/£ ratio - PFA/HV 36.04 200-300W 4, 8 v, 16 it 5d8 dynamic headroom Hand free operation Drives 70V line direct. 20 Amp capability PFA500 42.00 250-600W 2 u, 4 v , 8:: 25A cont. output current. DCV, ACV, DCA, ACA, 52.50 mounted on type 74 Heat Exchanger (see below). Ohms,Capacitance, Temp *The power output of these amplifiers can be increased by approx and Level in dBs t. 15% with no diminution in quality by adding PSU102 (£7.81) to your Meet DIN 40050, 43780, existing power supply. 57410 or 57411 Requirements Some Other Products & Components Type 74 Heat Exchanger. Dissipates 300 W (1.2KW fan cooled) Prices from approx £27 includes FREE Batteries, manual rwr £7.50 and Test Leads 25A 400PIV Bridge Rect. £2.17 Hand Held Models 6000Z and 3300A 1 0,000uF 80v electrolytic with clip £4.75 MIC alit PAN20 Pre -amplifier module. Very low noise and distortion £7.61 3% digit LCD with easy PAX2/24 2 Way active crossover (specify frequency) £10.10 single rotary control. PSU1 03 Powers 2 x PAN20 + 2 x PAX2/24 £8.91 10 Amp., 1000V and PAN1 397 20W power amp. (LOW THD) £5.04 20M ohm capability. PSU101 Powers 2 x PAN 1397 £3.43 - TRANSISTOR hFE Transformer for above £4.30 (inc. postage) measurement. TOROIDAL TRANSFORMERS Audible Continuity with special low flux -windings check and Diode Test. Nom. VAC 160VA 225VA 300VA 500VA 625VA 750VA Optional accessories 40-0-40 10.43 12.00 13.04 - incl. Carry Case and 45-0-45 - 12.00 13.04 18.96 - Battery Eliminator. 50-0-50 - - - 16.96 19.84 22.00 Fully Guaranteed for 12 70-0-70 - - - 16.96 - months. (for PFA/HV) Transformer prices include postage. Ask for leaflet "Choosing a Transformer." Prices from approx £39 include Free Battery, Carriage 75p. Add VAT at 15% to all prices. Manual and Test Leads Prices do not include VAT or P 0. House of Instruments THE POWERFET SPECIALISTS Clifton Chambers, 62 High Street Saffron Walden, Essex CB101EE pantechnic Tel: (0799124922 Telex: 818750 Mail order only to. 60114,10 d Dept ETI i8 148 Quarry Street, Liverpool L25 6HQ VIS4 CREDIT[xten available Telephone: 051-428 8485 Technical enquiries hi! compel ite hi! House of Instruments Ltd. Phil Rinunet 01 800 6667 60 ETI AUGUST 1983 PROJECT RADIO CONTROL SERVO FAIL-SAFE Up, up and away? Bringyour model aircraft down to earth without a bump using the ETI Conservo.Phil Walker showsyou how to makeyour servos fail safe.

No -one who has spent many + SUPPLY 0 IN 0 + SUPPLY hours and pounds OUT constructing their radio- D4 NOTE IC1 PIN 14 controlled boat, plane or animated IC1 IS 4093 aardvark would want it to sail, fly D1-4 ARE 1N4148 4 or crawl out of range of their R1 IC1d 0 OUT 10k transmitter. However, there is D2 IN IC1c 15 always the remote possibility that IC1b 5 some nasty little gremlin will creep 2

in and throw the spanner in the R4 33k works. When that happens all your R2 IMO controls may well be stuck in the 12 DI D3 RV1 100k last position you used; and by a IC1a R5 13 IC1 PIN7 well-known Law of Nature (Lex R3 C2 = +47u C3 Divoti*), the position will make it 4n7 IMO 47n T 16V OV IN 0 as hard as possible to retrieve your 0 OV OUT model. Help is at hand! This project Fig. 1 Circuit diagram of the Conservo. will set your servos toany position you require (if you fit it beforehand) HOW IT WORKS and if set up correctlyyour precious model should sail, fly or waddle home safely. R1 and R2 protect the inputs of the whose output will then go low and CMOS devices from overload or static discharge C2 via RV1, R5 and D3 until damage. The normal input to the device the lower threshold of IC1c is reached. Use is a series of 1 to 2 ms positive pulses IC1c's output will then go high again The ETI Conservo is simply repeated at about 20 ms period. When and the cycle will repeat. When the out- connected into the servo leads (get the input is low, IC1a holds C1 high via put of IC1c is low, the output of ICid D1 thus maintaining IC1b pin 2 at a high will be forced high. The component the polarity right) and the variable level. values used in the circuit are such that resistor can then be set to make the When a pulse arrives, the output of this cycle approximates to the normal servo take up what you hope is a IC1b goes low, discharges C2 and forces servo control signal with RV1 controlling safe position. This setting is best the output of ICid high for the duration the pulse width. of the pulse. When the input pulse goes If for any reason the input sticks at a done with slightly used batteries,to low again, C2 starts to charge via RV1 high level, C1 which is normally kept get a true position. Do not have the and R4 but will be discharged again by charged up by IC1d will have time to radio link operating while doing this another input pulse before its voltage discharge effectively putting a low level or you won't be able to make the reaches the trigger threshold of IC1c. on the input to IC1b. This will cause the setting. This means that the output of IC1c will same sequence of events to occur as stay highpermanently in normal when the input stuck low but after a If your system uses low voltage operation. short delay. (ie, around 3.6 volts) don't forget to If another pulse does not arrive and Finally, D4 and C3 form a reserve increase the size of C2 to its higher the input stays low, the output of IC1b power supply to ensure that the circuit is will stay high and C2 will charge up until not affected by supply line transients. value. its voltage reaches the threshold of IC1c The Circuit The circuit of this project is designed around a 4093 CMOS quad Schmitt trigger. This device will operate down to quite low supply voltages while still providing reliable switching performance. One section of the device (IC1a) A small project (this is actual size) but a is used to detect the possibility that long name - and a large degree of the input signal has stuck at a high usefulness.

ETI AUGUST 1983 01 PROJECT: R C Module level. Since normally the input only delicate things. PARTS LIST goes high for relatively short periods RV1 can be either vertical or at a time, the output from ICid horizontal mounting and the PCB is RESISTORS (+W 5% carbon film) spends most of the time at a high laid out for both. If you want to R1 10k level. This fact is used to charge a save space and weight use a vertical R2,3,5 1M0 R4 47k capacitor to near the supply mounting device and cut off the RV1 100k min. preset horizon- potential. This capacitor can only be end of the PCB as shown by the tal or vertical mounting discharged by a resistor connected dotted line. Inputs and outputs can in parallel with it and then only if it be soldered directly to the board or CAPACITORS C1 4n7F min. layer has enough time to do so. In alternatively, there are some 0.1 in. polycarbonate normal operation this will not be pitch PCB connectors available from C2 47nF min. layer polycar- the case. Maplin in 3 way versions which bonate (100nF for 3.6 volt operation) The second part of IC1 (ICI b) would do the job. 47uF 16 V min electrolytic combines the original input signal The whole unit could be C3 with the 'stuck at high' signal and mounted in a box or possibly just SEMICONDUCTORS its output goes high when either is varnished to keep out moisture (but D1,2,3,4 1N4148 low. Note that this output only not if the device is likely to be IC1 4093 usually goes low when normal immersed!). For use on low voltages, MISCELLANEOUS control pulses are being received. ie less than 5 V, it may be necessary PCB: see Buylines. 2 off 3 way 0.1 in. The low periods of the output from to increase the value of C2 up to connectors (if required). IC1b are used to discharge the 100nF in order to maintain the timing capacitor of the oscillator required output timing. formed around IC1c. The output from this oscillator would normally be a series of low going pulses of kR2 R1 approximately the same frequency R4 D1 IN as the usual control pulses. The OV width of these pulses can be set by +VE the variable resistor to simulate any D4 servo position required. However 11° +VE these pulses will only be generated OV if the normal input fails to discharge &R5 D3 &I( k D2 OUT the timing capacitor within a R3 reasonable time. k = CATHODE The output from the gated oscillator described above and the Fig. 2 Overlay diagram of the Conservo. Here we show a horizontal preset, but a vertical one could be used to save output from IC1b are combined in space - just cut the PCB along the marked line. ICid to give the final output from the unit. In normal operation the output will follow the input with no alteration as Cl will not discharge enough and C2 will not charge enough to have any effect. In a fault condition, however, the output form IC1b will stay at a high level (driven either by the input being low or by IC1a detecting the input high) and enable the gated oscillator (IC1c) whose output will be passed on to the servo being controlled. This will send the controlled servo to its preset position. Construction This should pose no real problems provided that care is taken to put the diodes, IC1 and C3 the right way round. This is a little more awkward than usual since FOOTNOTE some components must be *For those of you who are not mounted vertically to conserve PCB scholars of Latin, Lex Divoti is a area. Law of Nature known by a number BUYLINES A socket is recommended for of names, most of them not None of the components in this project 10 - at least the first time you printable, but can be summed up should be at all difficult to obtain. The build it. Take care when handling as: "If something can possibly go PCB is available through our PCB service 1C1 to discharge yourself of any wrong, it will, at the most - see page 77 for details. static charge. This also applies to inconvenient moment and in the your soldering iron which must be way that causes maximum earthed. CMOS devices are still damage." ETI ETI AUGUST 1983 62 BBC COMPUTERS BBC SOFTWARE IN EPROM Model B 346.95 Wordprocessor "View" 52.00TL014 0.24 04 0.12 248 0.55 Model 6 + Disc Interface 441.95 12 MOS 11021 00021 401201 olo 05 0.12 249 0.55 (Carriage 6.50 by Securicor) 11061 0.16 08 0.12 251 DATA SHEETS are10110 030 SPECIAL TL062 049 4013 Please phone to check delivery available on items 020 09 0.12 253 0.35 TL064 0.40 10 0.12 257A 0.30 BBC MICRO DISC DRIVES OFFER marked D. TL066 0.29 4015 0.36 11 0.12 258A 0.35 DI0.75 052.50 BBC 31 Single 100K Drive Expandable to Spectrum 32K TL068 020 12 0.12 259 0.55 021.00 06 3.00 2x100K 199.00 Upgrade Kit TL071 0.32 13 0.12 261 1.00 BBC 32 Dual 100K Drives D034 21 25 DI 4.00 330.00 TL072 00.472 4°401187 0.36 14 0.25 266 0.20 BBC 33 100K Upgrade for BBC 31 140.00 24.95 TL074 01..2600 0.36 15 0.12 273 0.54 BBC 34 Dual 400K Drives 575.00 TL081 40204019 0.36 2D 012 279 0.30 BBC 35 Utilities Disc , 25.00 06 TL082 0.46 4021 0.40 21 283 MEMORIES FD1795 0.12 0.40 (supplied only with BBC 31, 32, 34) TL084 1.58 4022 0.40 22 0.12 290 0.39 2114L 200ns DI0.80 FD1797 D6 28.111 All Disc Drives (except BBC 33) a re complete with TL091 0.40 4023 0.13 26 0.12 293 0.39 2706 450ns D2 2.95 WD1691 02 12.00 Manual, Utilities Disc, and Connecting Cables TL092 0.32 27 0.12 365 0.27 2716 45Ons 012.45 WD2143-01 02 6.99 TL094 0.13 28 0.12 366 027 BBC MICRO UPGRADE KITS 2716 350ns DI4.95 INTERFACE DEVICES 11.487 444000222654 0.74 30 0.12 367 027 BBCA2B Complete A to B Upgrade 44.75 2716 3 rail DI7.25 6402 3.80 TL489 020 32 0.12 368 0.27 BBC 1 16K Memory 1000 2532 450ns 02 3.45 75107 0.32 33 0.12 373 0.62 BBC 2 Printer/User I/0 Kit 7.50 2732 45Dns DI 3.45 0.560.47 1149611494 0.601. 40314028 0.94 37 0.12 374 0.62 BBC 3 Disc Interface Kit 95.00 2732 35Ons DI5.45 751100011623458 75150 5507 1.80 40 0.12 375 0.35 only supplied with Disc Drives. 2764 300ns 015.99 75154 0.770.64 725 160 4034 0.94 42 0.28 377 0.60 BBC 4 Analogue Input Kit 6.70 4116 15Ons 02 0.85 75160 0.144035 0.38 47 0.35 378 0.60 BBC 5 Serial I/O & RGB Kit 730 4116 200ns 02 0.80 75161 13227050800 777444871 0.48 4040 0.36 48 0.45 379 0.90 BBC 6 BUS Expansion Kit 6.45 4118 15Ons DI3.25 75162 0.36 49 0.12 386 0.35 All Kits are supplied with full fitting instructions 5516 20Dns 132 9.45 75172 0.34 51 0.12 390 0.45 6116 15Ons PRINTERS DI 3.30 75173 1.44 0.36 54 0.12 393 0.45 6116 Low Power 18105 NEC 8023 Printer 75174 1.95 0.30 0.36 55 0.12 (Carriage 10.00) 320.00 15Ons DIL JUMPERS 02 4.95 75175 1.44 78112 1.35 73 0.18 4164 150ns TI Single Ended 24- BBC CONNECTORS 03 4.45 15182 0.50 78LI 5 0.30 4446 0.42 74 °16 4164 20Ons TI 14 pin 1.45 BBC 21 Printer Cable and Amphenol Plug 03 3.95 75183 0.50 7805 0.40 4047 0.70 75 0.18 4164 150ns 16 in 1.65 (not assembled) 13.00 75188 0.37 7812 0.40 4048 0.38 76A 0.17 Mnstek 24 pin 2.40 BBC 22 User Port Connector and Cable 36" 2.46 D3 4.45 75189 0.37 7815 0.40 4049 0.23 78A 0.18 4516/4816 100ns 02 2.25 40 pin 3.80 BBC 23 Cassette Lead 3.50 75451 0.22 7905 0.23 83A 0.36 4532 200ns D2 2.95 BBC 24 7 Pin DIN Plug 0.60 75452 0.22 7912 00. 4°5°4051.45 0.38 85 0.42 Double Ended BBC 25 6 Pin DIN Plug 7915 0.45 0.60 6800 FAMILY 75453 0.22 4052 0.44 86 0.16 6" 12"18" BBC 26 5 Pin DIN Plug 0.60 012 IM309K 40534 044 90 022 14 PIN 1.85 1.98 2.42 6800 07 225 15454 BBC 25 Disc I/0 Cable 34W ICIC to 2x34 75468 LM317K 21/6.40 16 PIN 2.05 2.15 2.58 6802 D5 2.50 0.88 0.85 91 0.60 way card edge 12.00 75491 LM323K 4.50 4055 0.85 92 24 PIN 3.00 3.15 3.96 6809 06 630 0.31 0.32 BBC 36 Disc Power Cable 6.00 75492 LM338K 625 4060 40 PIN 4.65 4.90 6.18 6810 DI 115 0.42 0.39 93 0.22 BBC 44 Analogue Input Plug and Cover 2.25 AY31015 0.85 958 6821 03 1.00 02 3.00 DATA CONVERTERS 0.40 BBC 661M Bus Connector + 36" Cable 3.50 AY31270 6.47 40664°83 0.24 109A 0.27 25 WAY D -TYPE 6840 D4 175 UPD7002 BD,/ 3.4.4526 06 440 4068 0.14 112A 0.20 CONNECTORS BBC ACCESSORIES 6845AY3891005 5.50 ZN425 1190 4953600 02 6.70 4069 0.14 113A 0.20 Male -Male BBC 45 Joysticks (per pair) 6850 021.10 ZN426 131 3.00 DP8304 012.50 4070 0.13 114A 0.22 36" Cable 12.00 BBC 67 Eprom Programme (assembled) 57.95 68488 D27.30 MC1488 ZN427 Male -Female BBC 71 Teletext Receiver 225.00 68600 07 5.25 DI0.37 0.13 122 0.28 MC1489 ZN428 DI4.75 68809 DI 0.37 123 0.34 36" Cable 12.00 BBC 72 Second Processor (6502) 170.00 D6 12.00 ZN429 2.105.99 MC3242A 6.30 0.14 125A 0.24 Male single ended BBC 73 Second Processor (Z80) 170.00 68610 DI2.26 ZN432 DI 13.00 MC3446 DI2.50 4075 0.13 126A 0.25 18" Cable 4.95 681321 D3 220 ZN449 DI2.55 ACORNSOFT FOR THE BBC MC3448A 4076 0.43 132 Female single ended D46. DI 175 0.34 SBEO3 Business Games 8.65 MC3480 057.30 CRYSTALS 44007787 0.13 136 0.25 18" Cable 3.95 568145°0 D2 2.0020 SBE04 Tree of Knowledge 8.65 MC3487 0/2.00 1M 2.75 015 138 0.25 SBE02 Peeko Computer indManual 8.65 ZOO FAMILY MC14411 017.65 1008M 2.75 0.13 139 027 IDC CONNECTORS SBE01 Algebraic Manipulation Pb 8.65 280ACPU 02 2.99 MC14412 9.45 1.8432M 1.92 440°8821 0.13 145 0.57 (with ejectors) 0.70 SBX01 Creative Graphics Cassette 8.65 ZEIOBCPU D2 9.00 00325131 DI6.50 2.4576M 2.00 4085 0.50 148 (Right Angle PCB Mfg) SBX02 Graphics and Charts Cassette 8.65 Z8OACTC DI2.80 R032513U DI6.50 3.6864M lit 4086 0.44 151 0.40 10 PIN 0.86 ZBOBCTC DI9.00 4093 000 14 PIN SBB01 Desk Diary inc Manual 8.65 , UHF MODULATORS 4M 064 020 153 122 SBLO1 LISP Cassette 14.65 280ADART DI5.50 4502 0.46 155 030 16 PIN 1.34 UM11116MHz 6M 0.86 SBLO2 FORTH Cassette 14.65 280ADMA 02 6.95 8M 4507 0.32 156 0.35 20 PIN 1.46 2.60 0.86 SBG01 Philosophers Guest 8.65 Z80AP10 DI2.75 0.96 157 025 26 PIN 1.76 UM1233 8MHz 01 9.8304M 1.68 SBG07 Sphinx Adventure 8.65 113013P10 01 9.00 19.6608M 56 0.40 168 0.30 34 PIN 2.06 DI3.90 SBG03 Monsters 8.65 280A510 04 9.00 4511445108 0.41 160A 0.32 40 PIN 2.32 OIL SOCKETS SBG04 Snapper 8.65 BUFFERS (TEXAS)2S) 0.40 161A 0.35 50 PIN 2.35 8080 FAMILY PINS TINGOLD WW SBG15 Planteoid 811S95 44551142 0.96 162A 0.35 60 PIN 3.20 8085A Del 3.50 8 7 16 SBG06 Arcade Action 108.650.80.35 81LS96 0.80 25 4515 0.96 163A 0.35 8212 26 IOC SOCKETS SBG05 Rocket Raid 8.65 11014BILS97 0.80 10 35 0.40 164 040 8216 1.00 16 10 29 40 Fitted with 36" cable SBG13 Meteors 8.65 812698 O 44551186 0.40 165A 0.50 8224 33 10 PIN 1.40 ns 2.10180.90 13 50 4519 027 166A 0.60 8.658726A8228 127 14 PIN 1.82 SBG14SBG1O Chess ArcadiaM 20 15 37 60 8.65 8T28A 0.90 4520 0.40 173A 0.55 8251A D5 2.50 22 17 38 16 PIN 2.10 8795 0.90 65 090 174 0.40 ACORNSOFT BOOKS FOR THE BBC MICRO 8253 4.00 20 PIN 2.48 8797A 0.90 24 21 45 70 4522 062 175 638 SEID01 Creative Graphics 7.50 8255A D5 2.25 28 24 55 80 26 PIN 124 0.90 0.52 181 0.90 SBDO2 Graphs and Charts 7.50 34 PIN 3.50 6500 FAMILY 40 30 76 99 0.52 190 0.35 SBDO4 LISP 7.50 L811-749E0ARS 40 PIN 4.90 6502 D3 3.25 ZIF SOCKETS 44552287 0.41 191 0.35 SBDO3 FORTH 7.50 L203 0.65 50 PIN 648 6502A 03 5.00OO (TEXTOOL) 4532 0.72 192 0.35 Please ring for current delivery on Acornsoft LF398N 4.75 6520 Dl2.50 24 pin 4541 0.50 193 0.35 Products before ordering. LM301AN 5.75 65213A DI3.16 28 pin 820 0.50 194A 0.35 DATA BOOKS by LM308N 0.40.2411 6522 D5 119 40pin 9.75 44455543r5 1.57 195A 0.35 BBC MICRO COMPONENTS LM311P 0.50 6522A 05 5.50 0.35 196 0.45 Linear Control 4516 10Ons 2.25 8271 36.00 LM319N 6532 D2 5.50 0.35 197 045 Circuits 4.00 6522 3.19 20 Way Header 1.46 LM324N 01;91 4000Ch1°S 4°11° 0.10 45854558 0.75 221 0.46 Voltage Regulators4.50 74LS244 0.59 26 Way Header 1.76 FLOPPY DISC LM348N 0.60 4001 0.10 240 0.55 MOS Memory 3.95 74LS245 0.69 34 Way Header 2.06 CONTROLLERS NE555P 0.16 4002 74LS SERIES 0.12 241 0.55 Interface Circuits 7.011 74LS163 0.34 40 Way Header 2.32 8502711771 36.00 NE556CP 0.45 4006 0.42 00 0.11 242 0.55 TTL 5th Edition 8.50 DS3691N 4.50 15 Way D Skt 2.15 0515.00 711310 0.39 4007 0.14 01 011 243 0.55 Bipolar Micro 4.50 DS88LS120N 4.50 6 Way DIN Skt 0.90 FD1791 06 22.00 TL011 0.32 4008 0.32 02 0.11 244 0.55 TTL Pkt Guide 3.50 UPD7002 4.50 5 way DIN Skt 0.90 FD1793 06 23.00 TL012 0.34 4009 024 03 0.12 245 0.70 Linear Pkt Guide 2.50

Carriage Orders rip to I 199 1-, ;. nt oV 1st t DOS'

0 I I :ry S, or 0M1 WM WIN - MO MI WIN MN

t 10(1t '`19 1 Please complete this coupon for a copy of our FREE Prices riurrthr1 4-, mr..1(lertorgur,. aro Pet:oily, VAT catalogue. 2531/14 .ult... tr ,t oto

Quantity Discounts ,r,, LL ' nio rot for .1,of,

Official Orders . , voIt our,' 1' rut E dur I 00,1- uot,, ,i//111/ /I. .111 ADDRESS Credit Accounts Lr, .,3,-itor r.,or,,,rs ,.):nr,,IL; .,.).,., r , r1., nn rii.11-41, of ,rorrt., Credit Cards I. Arl Vi..trol tr,. I. I ' I .1 NC) r. I, Out of stock 1.... , our.. I/ f111 1 All. 1/1/11,-. oot,r.r.tr M I DWICH COMPUTER COMPANY LIMITED RICYINGHALL HOUSE RICIUNGHALL. SUFFOLK IP22 1 NH TELEPHONE 103 7 9) DISS 898751

ETI AUGUST 1983 63 All devices guaranteed Brand New and to full spec. Items ex stock despatched same day. Pricesare EXCLUSIVE of VAT. Please add 60p to order to cover P&P BEFORE calculating VAT. Payment by cheque, 'Postal Order, Bankers Draft or Gash (PLEASE register) with order. Official orders from Govt. Depts and Educational Institutes Welcome.TradeAccounts openedsubject to satisfactory status -send for details. COMMQUIP We are pleased to receive overseas orders (please allow adequate postage - surplus refunded) which, LTD. unless accompanied by Bankers Draft in UK Currency may be subject to Bankers Commission and slight HAMILTON HOUSE 11 WALKERN ROAD delay in despatch. Overseas trade enquiries welcome -send for full details.VAT no applicable to export STEVENAGE HERTS SG1 300 orders. Price List detailing full range of components available - 30p refundable with first order. Please Telephone (0438)729771 Tele. 825178 G send SAE. COMPARE 0UR PRICES LINEAR CMOS 74LS TANTALUM 1N5408 19 555CMOS 80LM3909 ZN459 70 285 4000 11 4518 39 LSOO 11 LS153 BEADS ZENER DIODES 556CMOS 140LM3911 120 ZN1034E 200 4001 11 4520 48 LSO1 38 709 25 11 LS155 290.1/35 12 LM3914 175 4002 11 4521 90 LSO2 11 LS158 741 14LM391 S LOGIC ICs 330.22/35 122V7 -33V 500 MW 7 195 4007 14 4522 105 LSO3 11 LS157 5V1 -75V 1.3W 748 35LM13600 105 4008 34 4526 55 250.33/35 12 14 9400CJ LSO4 12 LS158 270.47/35 12 345MC1498 68 AY5-2376 5904009 24 4527 55 LSO5 12 LS160 AY -3-1270 710MC3340 120 MC1488 55 4011 4528 45 300.68/35 12BRIDGE AY -3-8910 11 LSO8 12 LS161 351.0/35 12RECTIFIERS 370MF1OCN 350 MC1489 55 4012 14 4531 65 LSO9 12 LS162 AY -38912 540ML924 195 MM5303 625 4532 60 351.5/35 14 4013 20 LSIO 12 LS163 352.2/35 1A/100V 20 CA3048 60NE529 225 MM5307 12504015 4538 60 L$11 16 39 12 LS164 403.3/35 17 1A/200V 23 CA3080 65NE531 135 MM58174 7004016 20 4539 80 LS12 12 LS165 CA3089 190NE544 180 TMS601 1 4543 60 5010/25 181A/400V 25 3654017 32 LS14 22 LS168 1A/800V CA3090A0370NE555 16 ULN2003 75 4020 4555 35 LS'S 8015/25 28 38 CA3130E 42 12 LS170 702.2/16 142A/100V 36 85NE556 45 8726 99 4021 39 4556 35 LS20 12 LS173 CA3140E 36NE565 110 8T28 4561 100 473.3/16 142A/200V 40 120 4022 39 LS21 12 LS174 2A/400V CA3181E 100NE566 140 8795 90 4023 4583 80 LS22 364.7/16 16 40 12 12 LS175 36 6.8/16 162A/800V 52 CA3189 200NE567 100 8T97 90 4024 32 4584 40 LS27 12 LS181 CA3240E 110NE570 370 81 LS95 80 4585 50 87 10/16 1825/100V 4025 12 LS28 14 LS183 10515/16 2725/200V ICL7108 680NE571 370 81LS96 80 4027 20 LS30 12 LS190 ICL7611 95RC4136 55 81LS97 80 COMPUTER ICs 3522/16 2725/400V 4028 37 LS32 13 LS191 3533/16 4025/600V ICL7621 180RC4558 45 81LS98 85 4029 43 LS33 14 LS192 ICL7622 180SL490 250 6522 310 4035 1802 650 LS37 3547/16 40REGULATORS 45 14 LS193 36 100/16 75 IC L8038 290SL76477 380 6532 675 4040 40 2650A 1175 LS38 14 LS194 ICL8211A 150SP8629 250 6821 110 6502 32 15/10 2278L05 4042 38 320 LS40 12 LS195 32 30 ICM7224 775TBA120S 70 6845 6504043 6800 220 LS42 22/10 2478L12 ICM7555 40 28 LS196 4333/10 30 30 80TBA800 75 6847 6504044 40 6802 250 LS47 35 LS197 78L15 30 LF353 85TBA810 95 6850 1104049 6809 615 LS48 4547/10 3578L24 21 40 LS221 50 100/10 55 30 LF356 90TBA820 70 6852 2504050 22 8035 345 LS49 50 LS240 7805T 36 LM10 325TBA950 220 6875 4854051 8060 1090 LS51 55 100/6.3 427812T LM301A 42 14 LS241 55 38 24TDA1008 310 8155 3504052 48 8080A 250 LS54 14 LS242 7815T 36 LM311 70TDA1022 480 8212 1104053 8085A 345 55 63V MINI 7824T 48 LS55 14 LS243 55 MONOLYTHIC 36 LM318 120TDA1024 115 8216 1004066 22 Z80A 315 LS74 16 LS244 79L05 60 LM324 30TL081 40 8224 110 55 CERAMIC 79L12 4068 14 LS75 16 LS245 70 60 LM334Z 90TL062 60 8226 2504069 13 MEMORIES LS76 16 LS251 79L15 60 LM335Z 120TL064 95 8228 220 28 10nF 107905T 4071 13 LS78 17 LS253 3022nF 42 LM339 45TL071 25 8243 2704072 13 2101 395 LS83 33 1079121 LM348 LS257 29 33nF 10 42 60TL072 45 8250 8654073 13 2114(200ns) 85 LS85 39 LS258 79151 42 LM358 55TL074 95 8251 2504075 2532 295 LS86 32 47nF 107924T LM377 13 15 LS259 53 68nF 42 165TL081 24 8253 400 4076 44 2708 225 LS90 22 LS266 10LM309K 130 LM380 65TL082 45 8255 225 2564 1000 18 100nF 14LM317K 4078 13 LS92 25 LS273 53 270 1.1.1381 120TL084 90 8257 4004081 2708 225 LS93 LM317T 120 LM382 110 12 22 LS279 30DIODES TL170 49 8259 3954082 12 2716(5V) 210 LS95 36 LS283 LM323K 350 LM384 130UA2240 115 8279 385 2764 38 LM723 4093 23 750 LS109 21 LS290 40 0A47 35 LM386 65ULN2003 75 8832 2504099 4116(200ns) 80 LS112 1078H05-5A/5V550 LM387 70 20 LS293 40 1N4001 4 120ULN 2004 75 9602 2204502 50 4118-3 325 LS113 20 LS365 LM393 95XR2206 285 Z8OACTC 260 4164 27 1 N4002 4RESISTORS 4508 110 420 LS114 21 LS366 27 1 N4003 LA1711 60ZN414 79 Z8OADART 7754510 45 5101(450ns)150 LS123 34 LS367 5 LM725 325ZN423 130 Z8OADMA 975 5204 725 27 1 N4004 5 4511 45 LS125 24 LS368 27 1N4005 Carbon Film, LM733 89ZN424 130 ZBOAP10 2704512 42 6116(150ns)375 LS126 25 6High Stab 5% LM747 1 N4006 7 60ZN425E 340 ZN425E8 3204514 110 6514 330 LS132 29 MICRO -MINI '/.W 1oil -1 nn 2 LPA1458 40ZN426E 290 ZN426E8 3204515 110 6810 115 LS136 1 N4007 100-1onn 2 LM2917 185 23 100V CERAM 1N4148 2 ZN427E 575 ZN427E8 5754516 50 LS138 24 PLATE CAPS Metal Oxide/Film LM3900 45ZN426E 395 ZN428E8 395 1 N5401 12 LS139 27 1N5404 2% Met. Film E24 5 LS151 30 141% Met. Film E24 8 1pF 10nF 7 1N5406 17

RECRUITING? SELLING A PRODUCT? It'seasy OR A SERVICE? GET MAXIMUM BENEFIT FOR to complain YOUR MONEY FIND OUT ABOUT OUR WHOLE RANGE OF PUBLICATIONS IN: about COMPUTING VIDEO advertisements. RADIO ELECTRONICS Simply telephone ASP CLASSIFIED The Advertising StandardsAutliority.i 01-437 1002 If an advertisement is wrong.we're here te put it right. (We take Access and Barclaycard) A.SA Ltd.. Brook Hnise,Torrington Place. London WC1E 7Htt

64 ETI AUGUST 1983 PROJECT Z80CONTROLLER COMPUTER This article describes the design board and two other types of board. details of programming will be given and construction of a simple The CPU board houses the in a further article. microcomputer control unit. micropocessor, a 2K EPROM Since the I/O ports are on (We called it MARVIN for reasons containing the operating system, a individual boards, you can addas that would take too long to second 2K of EPROM for the user's many or as few as you need. explain.) The unit is designed programs, 1K of RAM accessible to MARVIN's I/O board provides 16 specifically for control functions both the operating system and the latched output lines and 16 input which usually require complex users, and the selection circuitry for lines, which are TTL compatible. purpose-built hardware. Consisting the various types of external port You can use up to five of these of a microprocessor boards. and support The other type of board we chips, the unit is 4 MHz MEMORY CLOCK ADDRESS SELECTION PORT SELECTI/O SELECT shall describe cheap enough to BUS LOGIC. LOGIC SIGNALS be used as an BUFFERS provides up to ADDRESS alternative to eight individual hard -wired logic lines which can with the interrupt the advantage that its CPU. These are 2 x 74LS244 useful for function is 280A EPROM 1 EPROM 2 I/O PORTS (MONITOR) RAM allowing external determined by (USER) 2114 x 2 2716 2716 devices to force easily -changed CPU DATA ADDRESSES ADDRESSES ADDRESSES the CPU to carry software. BUFFERS 0000 -07 FF 0800-OFFF 8000-83 FF The system out a predesig- nated routine. A can be used in DATA BUS DATA TO typical use might conjunction with AND FROM I/O analogue be for controlling devices that need devices, heavy 74LS244 5V REGULATED POWER servicing at duty switching, INTERRUPT 1 AMP SUPPLY light dimmers, CONTROL MEMORY LAYOUT regular intervals, remote 0 0 0 0 . 0 7 F FEPROM1 -OP. SYSTEM using an external 0 80 0.0F F FEPROM2 -USER PROG clock to provide controllers, etc, 1000 RESET UNCLASSIFIED the timing. to control CONTROL 7 FFF This first part anything from a AC MAINS 8000 -83 FF RAM Stirling Moss describes the style computer Fig. 1 Block diagram of Marvin. functioning and controlled construction of the CPU futuristic home to a board. tutor. board.This will be followed by Although 2K of program may a description of MARVIN's I/O and Since there are so many seem small in comparison with the possible uses, the construction of interrupt board and of MARVIN's memory capacity of a personal operating system. only the central computer parts computer, it will hold a surprisingly (CPU, I/O, interrupt board) will be complex machine codeprogram, of EPROMs described; you will be left to chose up to nearly 1000 instructions. A Z80A running at 4 MHz external circuits according to your Several of the routines thatyou theoretically needs memory capable needs. Some additional interfaces are likely to need are built into the will be available from the kit of 375 nS access time. Most 2716s operating system, and are directly have an access time of 450 nS and suppliers (see Buylines for details). accessible to the user by simple although some may work two -byte instructions. Your program adequately, it is strongly Split Personality must be inserted into the EPROM recomended that for reliable For maximum flexibility, before use by a suitable PROM operation you make sure that you MARVIN is divided into a CPU programming unit. Some further buy 350 nS EPROMs. If you decide Computer projects are usually complex affairs,as anyone who saw the Cortex will testify. This one isn't. Design and development by Peter Grigson and DavidHarris. ETI AUGUST 1983 65 01O1 to make do with 450 nS types, then you'll probably be taking it in and double sided, but as PCBs with equipment: see Buylines for the socketshould3.2768the crystal for useMHz. the shoulda zerouser beinsertionEPROM, changed forceas to Also, we suggest that you PCBout quite is shown a lot. in Fig. 4. The PCB is TheConstruction component layout of the unlessconnectionspinsplated have throughyou been have between holes used access areto the maketo expensive, twosuitable sides.The PCB is difficult to make approx)thetoitsource yourself, align holes of thedrill. arethe you two cutPCB. must sides using If be youaccurately. avery 0.8do carefulmakemm (orAll Fig. 2. Circuit diagram of Marvin's main board. SELECTION XTAL 14 MHz 11T +5V O 32 SIGNALS 00 R2 IC3a 81>124 IC3b 6 212 64 0 30201 3 1k0 4 Al'34 3 >16 12 IC4bIC3d 132 >1 2 C IC12 87 -060504 ICla 10nCl IClb A7A6A5 345LC>la3736 IC4e 4 IC4d 15 >1 10 9 0090807 INT SELECT +5V 3 IC1c R3 12 K A10 IC49 jal>14 2C>18 >16 IC4f 17C> 7 +5V 424 +5V 2 +5I/ 18 +5V119 11 181_12. 330R AAll 0 AO 8 A D1DO 109 11 AlA 65 6 AlAO 118 A2 - A2 1k0R4 1113 D2 Al 6 6 Al D2 -- 11 I/O 4 43 A3 I/04 IC2 IC5c 14 D3 AA23 54 4 D3 13 12 I/03 A4 2 A4 I/O 3 LI 25 BURSQNMI IC6a 1615 D5D4 IC8 A5 IC9 15 13 I/0 2 IC10 AA67A5 17 1 A5 IC111/0 2 2-- 13A6 -- R5 17 06 00516 16 A7 1 14 10k 11 !Cid Idle 2 WAIT IC6b 12 IC5d D7 A8A7 0 23 2223 A9ASA7 06 717---.11 I/O 1 A9A8 915 95 A8A9 I/O =1. C2 106 SW1 RESET 1C6c 9 IC5e 181 CS 20 OE A 18 A10 CS 20 OE 8 CS 10 WE410 8 CS 10 WE +5V MREO10R0 RDWR 222 21 IC3e 1 9 IC4h 11 0 WRRD 1k0 R6 16 DO 14 2 161817 ODD NT D4D3D2 78 5 IC7 141513 0 D4030001 D2 DATA 9 D706 13 9 10 19 1112 00137 D6D5INT 20j)+5V NOTEC5C3,4C2 ISCl ARE 74LSO4Z80A IS 74LS14 74LS244 +5V PIN 7 ;PINS 1,10,19 +5V C12C10,11C8,9C7C6 IS IS ARE 74LS24574LS27 74154ARE 2716 2114 EPROMS RAM (SEE TEXT) tIC1,5,6PINIC 14 t IC3,4 IC3,4PIN 20 100nC3 100nC4 C5100n C6100n OFUNUSED IC3 ARE INPUTS NOT CONNECTEDAND OUTPUTS I Iii OV +5V, 1:( 0 I I FROM PSU Schmittdard oscillatortriggers la circuit a and whoseb form frequencya stan- instructionreset, the Z80 from will memory begin bylocation fetching 0000 an and HOW IT WORKS it. butlines10 andeach permanently 11 has have an theirindividual wired address to selection the and buses, data line tionit's used line for to eachprovide port. an IC12 individual is active selec- 1C12on- is a four to 16 line decoder, and internaltheZ80IC1cputis stabilised Z80's fromCPU, and mill inputthisfed IC2 at-up intooscillator 4requirements(R3 MHzresistor). the is by necessaryclock XTAL1;is NMI, buffered inputas it RUSIN,the hasto of fulfil out-the byno andthenaddressTherefore,hexadecimal, 6,RD detects low.bus it andplaces that then thisthis takes address MREQ Theonis less andthe memory selection logic, ICs 5 executing tionlinehigh(CS) logic. is impedancethat pulled takes low its state by bus the until connections memory the selectionThe selec- output to a enable inputs (QE) on the interruptruptandmayly when eitherboardbe selectedselection TOM RDis usable, and is line,bylow, WR. oneso INT so thereOnly of SELECT.port these oneis boardsoi* inter-lines one atR4.design,and a randomWA so IT they inputs location are are tied in notthehigh usedmemory by resistor inAt thisswitch but -on, execution would begin system.initialisationEPROMthan 07FFH MARVIN program and then proceedsin the operating with the containing enables the operatingIC8, the enable)from(write).EPROMs the Z80,inputs are and are connected the connected RAMs' to WE RD to (write (read)IfWit the MPU wants to perform an out- terrupt),device.bemallyINT pulled held ratherBecause it ishighlow possible than byby we aR3;NMI have suitableto however, (nonprogram chosen maskable external MARitTheto may use interrupt - in- line itself, INT, is nor- beregisterlowfor resetC2 until (via contents at voltages IC1dany futurestabalise.and and e) time holding internal The by CPUmomen- RESET CPU may SW1 de - dataof two canbus 74LS244s, passby a tosingle and ICs 74LS245,from 3 and the 4, CPU, andIC7.The IC7theAs address bus is buffered by most thetainlow;put port(in orbinary, addressto input be selected. of operationlines course) AO Either theand it takesnumberRD A3 orwill WRIORQ ofcon- terruptwillbeenVIN be to done, toaccordingignore make the interrupts. resultthe to CPUyour of pulling predesignatedserviceIf this INThas the lownot in- SOLDER ON BOTH SIDES bouncingtarily is unnecessary). After being closing (note that hasEPROMs, to be a ICsbidirectional 8 and 9, and device. the RAM, The ICs canport be islow, to bedepending read from on or whetherwritten to. the routine. R5R3R1,RESISTORS 2, 4, 6 (all W 5%) PARTS LIST 330R1k010k C2C1CAPACITORS 10u10n ceramicaxial electrolytic IC1SEMICONDUCTORSC3, 4, 5, 6 74LS14100n ceramic or 7414 or polyester 1061051C3,1C2IC7 4 74LS244Z80A74LS24574LS2774LSO4 oror 74277404 MISCELLANEOUSIC10,IC12IC8, 11 9 7415421142716 EPROMRAM (300nS (see ortext) less) connectorXTAL1SW118IC sockets:pin; Veropins if required; one (about40 ribbonpin, 130); two cable. 24PCB; pin, edge. two 4switchpush MHz to ascrystal make required (seesingle text) pole 1,2 co cn, .5V 0 LINK THROUGH BETWEEN BOTH SIDES OF PCB I/O SELECTION SIGNALS vv.., z:<]ol¢13 D E) '2 2'A ?a' Fig. 3 Overlay diagram. PROJECT: Controller

ICs 2,8,9,10,11 should be (noting the polarity of C1). Where board to the others; we recommend socketed as they are NMOS there are pads on both sides of the that power connections to all the devices; Sockets are optional for the board the components' leads should bords be hard -wired to the positions remaining TTL ICs, and there should be soldered to both. There will provided and not taken through the be no problems in soldering them remain a large number of unused connector. If you're very cost- directly provided the usual holes, and many of these are used conscious, you could hard -wire precautions are observed. for the pins that link tracks on both direct; holes have been provided for To proceed with the sides of the board. You can tell you to insert pins for this purpose construction, first insert and solder, these holes by looking to see if next to the edge connector strips. on the underside only, all the TTL there are pads on both sides of the Finally, solder SW1 (reset) into ICs, and the sockets for the NMOS. hole: if this is the case, then you position, or, if you prefer, take off It is a good idea to use a fine -tipped should insert a pin and solder on wires to a control panel. soldering iron and to be careful to bothsides. check that you do not make any You can use a 24 -way 0.1 in. bridges between tracks, especially pitch edge connector where they pass between IC pins. to connect the Next insert and solder the crystal, resistors and capacitors BUYLINES The following will be available from ARK Electronics, Ashes Lane, Wentworth, Rotherham, S. Yorks S62 7TY: EPROM containing the monitor pro- gram, 4 MHz clock, £6.00; 3 MHz (or lower) clock £4.00; Double sided PCB, £6.00; Complete 4 MHz kitexcluding the operating system EPROM £26.00. Please add 50p p&p and make cheques payable to ARK Electronics. Sending an SAE to ARK will secure further details of D -to -A and A -to -D converters, lighting dimmers,remotecontrollersanda Next month, we'll be delving speech synthesiser. into MARVIN's I/O boards. ETI

THE VICTORYORGAN * Exciting range of authentic voices * Preset sounds-Piano, Harpsichord, Hawaiian Guitar (with glide), Banjo (with repeat), Accordion * 16 modern rhythms with superb sounds including handclap * Full range of Easi-Play' features * Custom Programmed ROM * Walking Bass on Lower Manual and Pedals * Real wood veneer cabinet with American walnut finish * The only organ with update facilities for synthesizer and "add -a -chord" unit * Starter kit from £98.80 + VAT * Full kit £280.54 + VAT Carriage extra on kits

Send for a demonstration tape today only £1.95 inclusive. Hear the difference yourself. Full details & specification on request LEIGHTON ELECTRONIC SERVICES

17BRIDGE STREET, LEIGHTON BUZZARD, BEDFORDSHIRE LU7 7AH TELEPHONE(0525) 382504

SS ETI AUGUST 1983 Interak I

THERE'S NO LIMIT TO WHAT A COMPUTER WITH NO CARDS CAN DO! Ald4* It's the oldest trick in the book to grab your attention with a stupid title, but in this case there's a grain of truth in the statement above. The Interak 1 Computer System is a 4MHz Z80A develop- ment system, one which you build yourself, perhaps for enthusiastic home use, or more often for industrial or ICS have educational purposes. ,,,41g°(:11W°Ce4C9 The fundamental structure is a 3U 19" rack which has helped thousands space for 13 cards ("International" size, i.e. 4.5" x 8") on 1" of ambitious people pitch, with space fora power supply at one end of the rack. International size - rack mounting: Inter-rak Interak! to move up into higher paid 13 cards 4.5" by b" gives a total potential board area of over more secure jobs in the field of 400square inches,enoughforacouple of hundred chi ps or electronics-now it can be your turn. more; there's no real limit on what that could do is there? (It would leave a few of today's marvels a bit in the shade Whether you are a newcomer to the field eh?) or already working in the industry. ICS can But don't be scared, you don't have to build a Frankens- provide you with the specialised training so tein's monster until you're ready. The first few cards are pretty straightforward: First the VDU -K, which can be con- essential to success. nected to your own T.V. (or monitor), then the Z80A-CPU card, the brains; then dynamic RAM, and finally the Key- Personal Tuition and Guaranteed Success board inter face (to any standard parallel ASCII keyboard), and you've got a computer- with the ultimate resource: 9 empty slots for the future. (Perhaps use one of them for a 2400 baud tape interface or later floppy disks.) Example prices (excluding VAT), everything is available separately and full after sales service in case you make a The expert and personal guidance by fully qualified mistake: Z80A CPU card £10.95, Manual £1.50, Main tutors, backed by the ICS guarantee of tuition until Parts £13.41. successful, is the key to our outstanding record in the 40 type -written pages of description, specification, price lists etc. are yours forthe asking (a 25p stamp and/or SAE is technical training field. You study at the time and a help, but not essential), or telephone if you prefer. You'll pace that suits you best and in your own home. In the have to live with your computerfor a long time, so make the words of one of our many successful students: "Since effortandfind out all about Interak now; acoupleof minutes starting my course, my salary has trebled and I am is all it takes to ask for a leaflet! expecting a further increase when my course is completed." City and Guilds Certificates Greenbank Greenbank Electronics (Dept. T8E), 92 New Chester Road, Excellent job prospects await those who hold one New Ferry, Wirral, Merseyside L62 SAG of these recognised certificates. Telephone: 051-645 3391 ICS can coach you for:

Basic Electronic Engineering (C 8 G/ICS) Radio Amateurs

1

1 a_o_orn- Certificate Courses 0 0, P TV Er Audio Servicing TV, Radio and Audio Engineering CastleHouse,1 CastleLane, BedfordMK4030E Radio Et Amplifier Construction Telephone0234 214219 Electronic Engineering* Pleasenote ournew address Computer Electronics* All components brandnew -Meese add 35p P&P plus15% VAT. Please send chequeor P.O. with yourorder. Offi- cial orders are welcomefromeducational establishments.Government bodiesand public companies.Credit Industrial Electronics* accounts are available.Pleaseask for details. Radio Frequency Electronics* LOW PROFILESOCKETS 8 Pin 9p 14Pin 10p 16 Pin 11p Electrical Engineering* 18,1::,n, let, 32Pin go 22 Pin 22p ORDEIr 12.0F ANY ONE TYPE AN g WEva...314LY 13. Electrical Contracting & Installation "A BAKERS DOZEN. SPECIAL FOR JUNE -JULY '83 *Qualify for IET Associate Membership MEMBRANE KEYPADS. By Pal., Multi -choice Graphics Keypad, 57 standard characters to choosee from. Blue Of Chile . standard graphic options keypad complete with flexible backing with Berg connector, ABCC

PANEL DIMENSIONS . ICACC ICS 30 4 - 79 x 98 min, 15.98 Div. National Education 4 x 4 - 97 x98 min lie.59 CorporationMember of ABCC 5x4-116x98mm £7.41 Approved by CACC TTL 7400 11p 7427 18p 7474 lap 7401 11p 7428 25p 7475 28p 7402 11p 7430 19p 7476 25p 7403 12p 7432 20p 7480 45p 7404 12p 7433 209 7482 65p Please send me your FREE School of 7405 14p 7437 23p 7483 30p 7406 19p 7438 24p 7485 00P Electronics Prospectus 7407 19p 7440 10p 7486 19p 7408 13p 7442 aop 7489 1809 7409 13p 7444 85o 7490 lap 7410 13p 7446 58p 7491 349 Subject 7411 16p 7447 36p 7491 24p 7412 17p 7448 43p 7493 24p of interest 7413 17p 7450 14p 7494 33p 7414' 33p 7051 14p 7495 33p 7416 19p 7453 14p 7496 389 7417 19p 7454 14p 7497 86p Name 7420 14P 7460 14p 74100 78p 7421 19p 7472 22P 74107 22p 7422 19p 7473 247 74109 24p Address CMOS 4000 10p 4020 42p 4042 38p 4001 109 4021 40p 4043 40p 4002 12p 4022 450 4044 40p 4006 50p 4023 16p 4046 40p 4007 14p 4024 33p 4047 219P Dept K265 400E1 36p 4025 12p 4048 38p ICS School of Electronics 4009 24p 4026 750 4049 21p 6 622 99i 1 4010 24p 4027 20p 4050 21p 160 Stewarts Road ,All Ho 4011 10p 4028 40p 4051 42p London SVV8 4UJ 4012 15p 4029 45p 4052 48p 4013 209 4030 14p 4053 48p 4014 459 4031 125p 4054 78p 4015 40p 4034 140p 4055 80p 4016 20p 4036 249p 4059 430p 4017 30p 4039 200p 4060 42p . 4018 45p 4040 40p 4063 80p 4019 25p 4041 Op 4066 22p Free - Satin Gold Biro Wee all onion over £3.00 le "Juno end July*"8.3

ETI AUGUST 1983 69 SERVICE SHEET

1982 appeared in December 1982). Send your Enquiries request to ETI Photocopies, Argus Specialist OOPS! We receive a very large number of enquiries. Publications Ltd, 145 Charing Cross Road, Lon- We have in the past published small correc- Would prospective enquirers please note the don WC2H OEE (cheques should be made out tions to projects on the letters page, and major following points: to ASP Ltd). corrections separately. From now on correc- We undertake to do our best to answer en- November 78 June 81 tions will appear on this page, and will be quiries relating to difficulties with ETI projects, November 79 November 81 repeated for several months (just to increase in particular non -working projects, difficulties April 80 December 81 our embarrassment). If a correction is too large in obtaining components, and errors that you September 80 March 82 to fit on here, we will publish it just once, but think we may have made. We do not have the October 80 May 82 will note the fact that a correction does exist, resources to adapt or designprojectsfor November 80 June 82 and that copies of it can be obtained from us readers (other than for publication), nor can December 80 July 82 provided you send in an SAE. But please - re- we predict the outcome if our projects are used January 81 August 82 quest copies only if you really do need them; if beyond their specifications; February 81 September 82 this service is abused, we may be foreced to Where a project has apparently been con- March 81 October 82 withdraw it. structed correctly but does not work, we will April 81 December 82 need a description of its behaviour and some May 81 February 83 sensible testreadingsand drawingsof oscillograms if appropriate. With a bit of luck, by taking these measurements you'll discover Write For ETI ZX A to D (Jan '83) what's wrong yourself. Please do not send us D2 is shown the wrong way round on the any hardware (except as a gift!); We are always looking for new contributors to overlay; wires on the RH side of the switch Other than throughourletterspage, the magazine, and we pay a competitive page rate. If you have built a project or you would SW1 should go to top contacts. Some of the Read/Write, we willnot reply to enquiries early PCBs had an error: pins 2 & 4 of IC1 relating to other types of article in ET!. We may like to write a feature on a topic that would in- terest ETI readers, let us have a description of should go to pin 16 (top) of edge connector make some exceptions where the enquiry is (published foil pattern is OK). very straightforward or where it is important to your proposal, and we'll get back to you to say electronics as a whole; whether or not we're interested and give you We will not reply to queries that are not ac- you all the boring details. We don't bother with the bureaucracy for companied by an SAE (or international reply ..Stage Lighting Unit (Jan, Feb, April, May coupon). We are not able to answer enquiries Tech Tips - all you do is to send in your idea, stating clearly if you want an acknowledge- '83) over the telephone. We try to answer prompt- Transformer specs are as follows: Primaries ly, but we receive so many enquiries that this ment of receipt. If possible, please type your explanation of why the circuit is different, what all 250 V; secondaries Tl: 0-6, 0-6 V, 12 VA cannot be guaranteed. tot; T2: 0-12, 0-12 V, 12 VA tot; T3: 0-6 V, 3 Be brief and to the point in your enquiries. it does and how it works, VA. ICs 34, 35, 36 are 7805 5V regulators. Much as we enjoy reading your opinions on from the circuit diagram; both sheets should world affairs, the state of the electronics in- carry your name, address and the circuit title. dustry, and so on, it doesn't help our already We'll let you know (within a month or so) if we overloaded enquiries service to have to plough want to use your Tech Tip. ZX Sound Board Design Comp. results, Feb through several pages to find exactly what in- '83) formation you want. The first line of the program has to be Trouble With Advertisers entered in reverse order to get it to go in (COS, GOSUB, COPY, ASN and RND are Subscriptions So far as we know, all our advertisers work functions). The line should read: hard to provide a good service to our readers. The prices of ETI subscriptions are as follows: However, problems can occur, and inthis UK: £13.15 event you should: 10 REM: "Y - ,=?COS GOSUB 5 COP Overseas: £16.95 Surface Mail 1. Write to the supplier, stating your com- Y ??ASN :RNDF??RND £36.95 Air Mail plaint and asking for areply. Quote any Send your order and money to: ET] Subscrip- reference number you may have (in the case of Alarm Module (MArch '83) tions Department, 513 London Road, Thornton unsatisfactory or incomplete fulfilment of an R21 is 220k (parts list OK, circuit diagram Heath, Surrey CR4 6AR (cheques should be order) and give full details of the order you sent wrong) Q5 is BC182L (left off parts list). made payable to ASP Ltd). Note that we run and when you sent it. special offers on subscriptions from time to 2. Keep a copy of all correspondence. time (though usually only for UK subscriptions, 3. Check your bank statement to see if the Max Min Thermemeter (April '83) sorry). cheque you sent has been cashed. A revised foil pattern was published in July ETI should be available through newsagents, 4.If you don't receive a satisfactory reply from ETI. To get original PCB to work, replace D4 andifreaders have difficultyinobtaining the supplier within, say, two weeks, write and D5 with wire links, cut tracks from pins issues, we'd like to hear about it. again, sending your letter recorded delivery, or 7 and 8 on IC6, and solder 15k resistor telephone, and ask what they are doing about across cut - remove ICs while doing this! your complaint. (It's messy but it works.) Backnumbers If you exhaust the above procedure and still do Below welistthe backnumbers thatare not obtain a satisfactory response from the sup- available from our backnumbers department. plier, then please drop us a line. We are not Real Time Clock (April '83) Please note that this list will be out of date if able to help directly, because basically the Frequency of XTAL1 is 32.768 kHz. youuse anoldcopy ofthemagazine. dispute is between you and the supplier, but a Backnumbers cost £1.50 (UK or overseas by letter from us can sometimes help to get the surfacemail)and are available from: ETI matter sorted out. But please, don't write to us NDFL Power Amplifier (May '83) Backnumbers Department, 513 London Road, until you have takenallreasonable steps C13 is 33p (parts list correct, circuit diagram Thornton Heath, Surrey CR4 6AR (cheques yourself to sort out the problem. wrong). Table 1: lengths of wire quoted do should be made payable to ASP Ltd). We are a member of the mail order protec- not allow for lead lengths - add 40 mm or Even if the copy of ETI you need is not listed, tion scheme, and this means that, subject to so to them. This is particularly important for all may not be lost, because we run a photoco- certain conditions, if a supplier goes bankrupt L3. Resistors R29 and R30 can be wire - pying service. For £1.50 (UK and overseas) we or into liquidation between cashing your che- wound types, it isn't necessary to use carbon will photocopy an entire article (note that parts que and supplying the goods for which you types (thier inductance will be small). of a series of articles count as separate articles). have paid, then it may be possible for you to Your request should clearly state what article obtain compensation. From time to time, we you require and the month and year in which it publishdetailsofthescheme nearour Flash Sequencer (July '83) appeared (the index for 1980 and 1981 was classified ads, and you should look there for Ql should be BC184L; Q2-5 should be published in January 1982, and the index for further details. BC182L. ETI AUGUST 1983 70 READER'S SERVICES

NM ION MIN - - NMI IMO-IIIMI NMI I= MN =I Mill NM IIIIIII Mil NMI MN =I MI INN MN- - - - .... Subscription Order. Form To: ETI Subscriptions Department, 513 London Road, 1I Binder Order Form I Thornton Heath, Surrey, CR4 6AR, England. To: ETI Binders, 513 London Road, Thornton Heath, Sur-I Please commence my subscription to Electronics Today Irey CR4 6AR, England. International.I enclose a cheque*/Postal Order*/Interna- I tional Money Order* for the appropriate fee*, made out to 1Please send me binder(s) for ETI.I ASP Ltd. I enclose a cheque*/Postal Order*/International MoneyI Please debit my Access*/Barclaycard* account number*IOrder* to the value of £4.25 per binder required, made Iout to ASP Ltd (* please delete as appropriate). I I I Signature I (* delete as appropriate) ITotal money enclosed £ Pleaseindicatesubscriptionrequiredandfee PLEASE COMPLETE YOUR NAME AND ADDRESS INI IBLOCK CAPITALS enclosed I I UK & Rep of Ireland: UK £13.15 IName I Overseas surface mail: £16.95 I I £36.95 Address Overseas air mail: I I I I Until further notice, each subscription includes a I free binder (normal price £4.25) I PLEASE COMPLETE YOUR NAME AND ADDRESS I I IN BLOCK CAPITALS I I Name I I I Address IPLEASE INCLUDE POSTAL CODE AS APPROPRIATE I I Date of order I INote that binders cost the same for UK and overseas; PLEASE INCLUDE POSTAL CODE AS APPROPRIATE Ioverseas orders will be send by surface mail. I Date of order I I THIS.. COUPON IS VALID UNTIL: 30th SEPTEMBER 1983 THIS COUPON IS VALID UNTIL: 30th SEPTEMBER 1983 1 ac num------er Order Form I Photocopy Order Form To: ETI Backnumbers Department, 513 London Road, ITo: ETI Photocopies Department, 145 Charing CrossI I ThorntonHeath, Surrey CR4 6AR, England. Road, London WC2H OEE,England.

I Please supplyme with the following backnumber(s) of ETI 1.1 Please supply me with the following photocopies:I Month Year IMonth Year Article Month Year I Page No I Month Year IMonth Year Article I enclose cheque*/Postal Order*/International Money I Page No Order* to the value of £1.50 per magazine ordered, made I I enclose cheque*/Postal C)rder*/International Money out to ASP Ltd (* delete as appropriate). IOrder to the value of £1.50 per photocopy ordered, made out to ASP Ltd (* delete as appropriate). Total money enclosed f PLEASE COMPLETE YOUR NAME AND ADDRESSIN Total money enclosed BLOCK CAPITALS PLEASE COMPLETE YOUR NAME AND ADDRESS IN BLOCK CAPITALS Name I Name Address I IAddress I I I I I I PLEASE INCLUDE POSTAL CODE AS APPROPRIATE IPLEASE INCLUDE POSTAL CODE AS APPROPRIATE Date of order Date of order Note that the cost is the same for orders from overseas as INote that the cost is the same for overseas orders as for UK for UK orders; overseas orders will be sent by surface mail. Iorders; overseas orders will be sent by surface mail. PLEASE CHECK THAT THE BACKNUMBER YOU RE PLEASE REMEMBER TO INCLUDE MONTH AND YEAR I QUIRE IS AVAILABLE BEFORE ORDERING. WHEN ORDERING. LTHIS COUPON IS VALID UNTIL: 30th SEPTEMBER 1983 I THIS COUPON IS VALID UNTIL: 30th SEPTEMBER 1983 MI NM INN NM Mil IMO ME MN NM MI NM MI MN NMI 1.11 MIN NMI NMI EM IIIN MI

ETI AUGUST 1983 71 PCB FOIL PATTERNS

-r-

.2.0win. itt

CC le ,I 1 sill

I

The Servo Fail -Safe i

I IC ,,,N,

i7 i. ,c ),,, ,f,, i,., 1, k j)

0000 % 0 0 0 00 00oot1000gg0: : : : g Universal EPROM Programmer PCB Foil Patterns 1

MARVIN V2 DJH 82 A 0 5

L J Marvin (component side)

L Marvin (solder side)

73 HOME COMPUTERS AQUARIUS ATARI 400/800 NEW LOW PRICES AQUARIUS: The brand new Aquarius Personal Computer is part of ATARI 400/800: With the Atari Personal Electronicslatestdevelopmentsin Computers, you can play the ultimate in advanced technology and offers full T.V. games, teach yourself new subjects A7CIEVrEUYirEC'530M71 home computing facilities, as well as or skills, balance budgets, and even write your own computer programs in Basic. -1SZEIP.2_771f:COTOC, extensive game play, using a very widerangeofplugincartridges. SPECIFICATIONS: Both the Atari 400 Since Aquarius is a Mattel Electronics and 800 can display in up to 16 colours, product, it benefits by the company's each with 16 intensities. They have four wide experience of producing high independent sound synthesizers for music technology equipment, as well as their game p ogramming expertise which is evident tunes/game sounds, giving four octaves from the advanced games which have been produced for the . Aquarius costs with variable volume and tone control on £79 and comes with built in. It 's so simple to use that you'll be writing your T.V.'s speaker. The display graphics your first programs within minutes of taking the machine out of its box. You can even are of amazing quality, having a detailed resolution of 320 x192, compriSing 24 lines of record the programs on your own cassette recorder at home, so you can use them again 40 characters. Atari personal computers have a standard 10K ROM operating system. In at a later date. Most available domestic tape recorders are compatible with the Aquarius. addition the standard Atari 400 (E149) comes with 16K of RAM, and the expanded A POWERFUL MACHINE: For allits simplicity, itis also very sophisticated. It has a version with 48K (£198). The Atari 800 (£299) comes with 48K as standard. Both the Z80A processor and 8K of built in ROM as well as 4K of RAM, which is user expandable 400 and 800 are now supplied with a FREE £40 Basic Programming Kit, which includes to 52K. It has a display of 40x 24 characters, and a graphic resolution of 320 x192 with the Basic Programming Cartridge, as well as a 120 page Basic Reference Manual and the a total character set of 256 (including the complete ASCII set with upper and lower case 184 page Self Teaching Manual by Bill Carris called 'Inside Atari Basic', so you can begin letters, numbers and additional graphic symbols). The keyboard has 49 full stroke programming straight away, without buying any 'extras'. Even a mains plug is supplied! moving keys, unlike some of the cheaper machines which have membrane keyboards. OVER 500 PROGRAMS AVAILABLE: The Atari computers are supported by well over The size of the machine (excluding any of the additional peripherals), is 13" x 6" x 2". 500 programs available for your use, a larger selection than you will find on any other television game or ! The wide selection puts Atari way ahead of the PERIPHERALS: Itis very easy to increase the capabilities of your Aquarius as all the peripherals plug straight into one another. You can add a Printer, a Modem, a Data competition. Just fillin the coupon and we will be pleased to send you a full price list Recorder, Mini Expander and other items. All of the peripherals are very easy to install which gives details of our range of software available for entertainment, home education, and what is more, they're easy to use. But the best news of all is, they're easy to afford. programming and home office use. We think you'll agree when we say it's quite impressive. CPM OPERATING CAPABILITY: The Aquarius is capable of being expanded to 52K 100 FREE PROGRAMS FROM SILICA SHOP: If you buy your Atari Home Computer RAM and later in 1983 a disk drive will be available for it, with the commercial CPM from Silica Shop, you will recieve a FREE presentation pack of 6 cassettes, containing business operating system. This will allow you access to one of the largest software 100 programs including games,utilities and demonstrations. A 16 page booklet giving full in the world, with literally hundreds of programs available for you to use. details of allof these programs is available on request. If you have already purchased libraries your computer elsewhere you can buy the set of 6 cassettes for £30. What's more, Silica CARTRIDGES: Various sophisticated programs will be launched on plug in cartridges Shop offer a two year guarantee on all computers as well as a FREE joystick. This adds such as a Visicalc type spreadsheet and a word processor. In addition there will be up to a great offer that we believe can't be beaten or matched by any of our competitors. dozens of games and utilities and alternative languages such as Logo, which combined with the built in microsoft basic gives an ATARI 400 16K - £129.57+VAT=E149 unbeatable combination of high quality programming ability. ATARI 400 48K - £172.17 +VAT=E198 ATARI 800 48K - E260.00+VAT=E299 MATTEL AQUARIUSVIDEO - £68.70 + VAT = £79 GAMES VECTREX COLECOVISION THE SYSTEM: Vectrex isa totally unique Home THE SYSTEM: The CBS Colecovision offers new standards in video game Arcade System, which has been exclusively designed and engineered to duplicate real arcade game play. Complete play. The excellent graphics are well with its own monitor display, Vectrex won't cause any implemented with arcade titles such as Zaxxon, Lady Bug, Gorf, Wizard arguments over the use of the family's television because of Wor, Carnival, Mouse Trap and the it has its own built in screen. lovable Smurfs. The console comes THE SCREEN: Vectrex does not use ordinary display supplied with a three screen arcade techniques, instead it uses vector scanning to control the quality version of DONKEY KONG. images on the screen. With this scanning method, the Parker and other companies have also gun only updates the area of the screen that has changed, announced ranges of cartridges for whereas a normal T.V. re -transmits the ENTIRE screen Colecovision, to further enhance the 50 times a minute. It is this that gives Vectrex its speed, wide range of quality titles available and means that very little computer power is required for this new television games machine. for screen control, and the results provide very fast responding and clear images. These 'Vector Graphics' THE CONSOLE: The CBS Colecovision video games system has advanced technology are used in several arcade games such as Asteroids and which produces superlative graphics resolution and excellent sound effects. The styling Battlezone, to give you incredibly high resolution and of the console and hand controllers has been carefully researched; the console is designed quality. Vectrex brings all of this from the arcade right to complement modern hi -tech equipment, and has clear features for easy operation. into your living room. The Vectrex screen is capable of The hand controllers allow fingertip control via the 8 direction joystick, and feature 2 displaying 80 columns by 40 lines, which is significant independent fire buttons. The push button keyboard is used for game selection and for to the extensive developments planned for the system. game control with some cartridges. The hand controllers are detachable and are connected to six feet of telephone coil cable, storing neatly away in the console when not in use. EXCITING SOUNDS AND ELECTRONICS: Vectrex has an advanced microprocessor with more speed and power and exciting effects than many home video games systems. ATARI EXPANSION MODULE: The Atari converter module allows Atari VCS software cartridges to be played on the Colecovision console, allowing owners the freedom to REAL ARCADE CONTROLS: Vectrex has a unique control panel, similar to those used purchase from the extensive range of Atari compatible cartridges.It also means that in many real arcade games, with 4 concave action buttons and a full 360° self centering existing Atari owners can buy the CBS Colecovision games system without discarding joystick. This control panel has a 4 foot detachable cord for maximum player freedom. their software library. Silica Shop offer part exchange facilities if you wish to upgrade. REAL ARCADE GRAPHICS: Vectrex has its own 9 inch vertical screen and unlike a TURBO EXPANSION MODULE: The Turbo Driver Expansion Module allows you to conventional T.V. screen, uses advanced display technology to achieve brilliant, high actually drive the vehicle that appears on your T.V. screen. The module consists of a resolution imagery and superb game play never before possible. The Vectrex display steering wheel, dashboard and accelerator pedal. One hand controller is mounted on the provides special effects too, such as 3-D rotation and zooming in and out, which a dashboard to provide a gear change unit. The module comes complete with a Turbo regular T.V. cannot match. Using a black and white monitor, each Vectrex game comes Driver cartridge, the first of several cartridges to make use of the module, which provides supplied with its own coloured plastic screen overlay to add to the excitement of game all the action of sitting in the driving seat. This facility is unique to CBS Colecovision. play. The range of Vectrex cartridges (£21.95 each), gives a good selection of arcade games such as Berzerk, Scramble, Rip -Off and Bomber Attack. Vectrex comes complete HOME COMPUTER EXPANSION MODULE: The Home Computer Module scheduled with a fast paced 'Minestorm' game built into memory. for late 1983, allows conversion of the games unit into a sophisticated Home Computer. This flexibility of design VECTREX: Vectrex has an advanced state -of the -art 49 is an important feature of the CBS Colecovision System. microprocessor with more speed than other T.V. games. COLECOVISION £127R2 +VAT =£147£147 VECTREX - £129.57 + VAT = £149.00 WHO ARE SILICA SHOP? r Mrs Shop are one of the leading speciered Inception of Video Gams IS Personal Computers. Vh eanikler tut our smite. to those who elevedy own or to those who Sd interelled in any Oratorio in Our 1111p. 0)0110I b RISICBSti by WI other supplier. we look at what wehad te. stir dsrnonstrst.an .0[11.11,84 at our SKIP ,n Scloup, to Nat you a.'ND.., SR...Dor a,.. DE BOISSTR TION F ACIL !TIES No 1,10.0 SKOV. OPENING ROAMS so vs upon Dom Mate. to Noun. S son5 30 , close stI Rol Thunchtv,And Rpm on Ends, 01-309 1111 MAIL 0501 no sea s posh., molt order company and No V. to RIPON woe.n. themour door to ..es FREE FIRST CLASS RELIVE RVNI order. an tont Rom And Poch, FREE. Nee ol Was dsPserBod byFIRST dots.it Vq. ire OVOIMI.1 em thn

SEIORIDN1410 0000S As No tocondhand Newt A Atv. consovokonudets Imer s h, I yr suorsivool or Aso thaesS of N. nomn0 NB. arcs II ..111111111111..#li en nom k000irRv undoes. RV will normally hunch envb. TITIVE PRICES bath our pron sod sservs ars sit, compontrn Boot. BvBy our cornsot,tou oroh...ns they sc rne ord. to vao Ron T prns NE LPFUL ADVICE our IPO(.0.11 WOO tuft ses shvort ays.lople to gen you NM. on th tuitstsleM1 a, moose =futon 'ill II 'III im11111 SERVICEMPAIRSors mvs.161s on so OW. utilising Nor n Boum on. hewn. Yr. ATRI SERVICE CENTREon are now an 1.0100.10:1 Run DPIK centre end con INBORN. sop ROB on Ns oso V Carouwnl S.k Sony Ah Nixon dorms rnsesdISIININ ISIESIBARnEnty t.0, to co* FREE OF CHARGE 2 VEAR ClUAR.TEE oNo I vow. Tension on moms mono IKAAnn 12 month SINNONO.BAS.011 AN. INN... CNN... SILICA SHOP LIMITED,.nlll Dept ZETI 0883, VIDEO GIMIES AND CENNUTER CLUBSNs oyhs, ,nfonn...... rm.. an OK. Elms eidoompuson A oar Ins* Advanced inform.... On NNW o.o.v. ro,0 evos, taw no. ma.... whon.snole.me to mon tun thot v. pot MO dul, 1-4 The Mews, Hatherley Road, Sidcup, Kent, DA14 4DX RS gni moos., vv:, good, ovsnoss.a...... en,* On.. Mum YR G. knee row assk.ORRON EARN or. .CODS Pon OK. TN*. Acosn'Syclaycsrd V.ss Arnwcan Outo pm*, .11 L.CREDIT FACILITIES ow sise offer crsdo loohoss soth urVooft 0.0f7.11 avec IE.OIS :MGM. Elmo ..1,0 %Au, FREE arm... so. *num 1:110,4K011 Telephone: 01-309 1111or01-301 1111 VIDEO GAMES Awns Awl ATARI ATARI/ContgMIMIQM Aerial Spl.tter 3 -D tic sac toe Super Brkout Erna Strks Bk Joysticks Adventure Surround Frogger Keyboards Air/Sea Battle Swordquest E Incredible Hulk Pain. AdaptorAsteroids Swordquest F James Bnd 007 Paddles Backgammon Tennis Wept) Jed. Arena Basic Math Vanguard Lord of Rings P Pace Proem, Volleyball Ir/s1Pop,. Ism Load Basketball I Warlords 0Bert Jai/sticks Basketball Iris/ Yen Pawnee Reactor Le thick Berzerk ATARI VCS (2600) - THE NO 1 BRAND LEADER IN THE U.K. Rtes of .ledi 1 PoIntrnaster Bowling ATA I EMQ Roma -Jell 2 (sack Snot Brain Games Asseult Sky Skipper AS Breakout ATARI: The Atari Video Computer System known as the Atari VCS or the 2600 has now Great Eenwa superman Sleeffehtar Cesmo become the T.V. game brand leader. In the U.K. there are over 700,000 owners of the Splendour Super Cobra Straight Stock Centopede VCS with access to a range of over 200 different plug in cartridges, each having a multitude Wall Defender Tutenkharn Treekball Checkers 2 .Tack Trigg Cornmd Chess of different variations and difficulty levels. Every system comes complete with the main EPCTRVNeeSION Vid CommandCircus console, two individual joystick controllers, a pair of paddle controllers, aerial splitter, CB5 (Coleeel ChM! o r Wicos Codebreaker Blue Print China Syndrnw Zircon Combat mains adaptor and a 27 game Combat cartridge. It gives you bright crisp graphics, realistic Carnive Crou Force Concentrat.o, sound effects and even specially designed circuits for the protection of your Television Set. Donkey Kong Gangster Allay akocE&S MIK Defender Gorf Glactic Tactic Video Storage Demons/Diem, Mousetrap Mangan Units Dig Dug SECONDHAND GAMES: We currently have several secondhand Atari VCS units in stock Srnurl Mager Builder Dodge's., which we are selling for only £49 (inc VAT). This price includes the Console, with Combat Solar Fox Planet Patrol ACTIVISION E T Turbo Tape Worm Bernstorming Footbell/acce Cartridge and all the accessories, as well as a 12 month guarantee. Venture Boxing Fun with Nos We also have stocks of several secondhand cartridges many at half Wings §UPEoliCn,,HZR Bridge Galexien Wizard of Wer COM Chopper C,nd Golf price (all with 12 months guarantee). We will normally buy back Zair eon Dragomtrnpor Dolphin Graviter secondhand units and cartridges at one third of our standard price. Etc.. from M OreMter Henan.. Fire Bell Endure Haunted Hut Atlantis Kole, Satellite Felling Elroy Humes Cann EXTENSIVE CARTRIDGE RANGE: The Atari VCS is so popular that in addition to Cowie A, Pheser Patrol Freeway Hunt & Score Atari's own cartridges, there are over 150 compatible cartridges, produced by at least a Demon AttackSuicide Mission Grand Prix Indy 500 dozen different third party manufacturers. Silica Shop has one of the largest cartridge selections available in the U.K. Our range of Dern AttackII Ice Hockey Jungle Hunt Dragonfire TELESVS Kaboorn Kangaroo over 200 titles (printed either side of this column), includes items in stock now, as well as many of the new releases for later in1983. Fe Fighter Coconuts Keystn CapersKroll No Escape Centric CoNNIO Laser Blast Meth G Prix SILICA ATARI CLUB: Silica Shop has over 20,000 Atari VCS club members registered on our computer. As a specialist company Riddle of Spa Dernolto Herby Megenanie Mace Craze ScupFtet Food Oink Min Golf we are able to obtain advance information about new developments and send detailed catalogues to all of our club members, enabling Startle., RamIt Pirlall Missile Grind them to evaluate new products before they buy. This is a totally FREE service, to receive your copies complete the coupon below. StarVOyMo Plaque Attack Ms Pee .Man Trick Shot TIGERVISION River Raid Nght Driver Zone Jayknooker Robotank Olympics SERVICE CENTRE:Atari International (UK) Inc has recently appointed Silica Shop as an authorised Atari Service Centre. This King Kong Seequest Othello means that we can now service your Atari VCS or 400/800 (under guarantee if applicable), whether or not you purchased it from us MNETWORK Marsucho Skiing Outlaw Advs of Trost Miner 2049er Sky Jonas Pac Men Air raiders Poleris Spider Fighter Pnoenix VCS COMPUTER KEYBOARD: A keyboard will soon be launched to convert the VCS into a fully programmable home computer. Burger Time Ron, Petrol Stampede Pinball For further details, join our club by completing the coupon below. We will then let you know when further information is available. Comp Revenge Threshold Stanwastip Pole Postn Frogs & Flies Tennis Raiders of L A STARPATH SUPERCHARGER: The supercharger plugs into the cartridge socket of your VCS and expands its RAM almost 50 fold, I ntnl Soccer ZIPAnt! Sky Dom. Lock n ChaseCos AIIppLEO Slot Racers from 128 to 6,272 bytes. This increased memory adds vivid high resolution graphics capabilities and significantly lengthens the game Specs Attack Dishaner Soccer playing time. Supercharger has a range of multi -load games (at £19.45 each), these offer the facility to play a iron Ddly Dec',runes & AOgs Racquetball Space Invaders Winter Olying I went my Morn Shark Attack Space; ar game in several distinct parts (great for adventures), the next section being loaded when you have completed Pine Chef Skeet Shoot Star Rders the previous one, thus enhancing the game play. For further information please complete the coupon below. PARKER, Guest for Gold Space Cavern Street Racer Action Force Tally Ho Space Ghee superman ATARI VCS CONSOLE- With Combat Cart & Accessories £68.70+VAT =£79.00 Amide, Tanks no Telles ACCESSORIES MATTEL We stock a wide range of accessories for the Atari VCS and 400/800 personal computers. The same accessories can be used on the Commodore VIC range of computers. The Wico range can also be used with the Texas Instruments computers on purchasing a special adaptor. To give you an idea of the range available, just take a look at the following list: INTELLIVISION MATTEL INTELLIVISION: The Trackball LE STICK: A mercury filled joystick specially made Mattel games un't is a most versatile by Wico or one handed operation, with thumb fire button. T.V. game which offers 3-D graphics QUICK - SHOT: This joystick features a contoured quality for only £98. Each cartridge handle grip, thumb trigger and optional base fire comes with 2 overlays which fit over button. Itis supplied with 4 sure foot suction grips. the unique hand controller giving easy directions for game play. Using STARFIGHTER: Neat and compact with a small the handset's control disc, objects direction stick. Metal interior for added strength. can be moved accurately in 16 directions giving a realistic simulation of lifelike movement. VIDEO COMMAND: With a VOICE SYNTHESIS: The Intellivoice unit, price £49, is used with special cartridges tapered handle, this joystick Wico where high quality synthesised male and female voices feature as part of the game play. is for one handed use. It has Straight Stick NEW MATTEL CARTRIDGE RELEASES: Why not complete the coupon below and ioin the Silica Mattel Owners a directional control which is similar to a jet fighter joystick. Club and receive our Mt news bulletins and 16 page catalogues detailing new Mattel releases. There wIll soon be over with ninety cartridges available for the Mattel, and a small selection from these is listed below: WICO RED -BALL: An arcade type joystick with a red ball handle, Stick it features 2 fire button locations, one at the base and one on the MATTEL:t!;;,Ar:otilcarSrtsu.a.iroes, sBurgeersTbiurritetieBuve., Bo,romnbe. vfs,,;ntCelleg, MoAuntievini,s1LoogNo Motion, Miasion %, Mystic Castle, Fire Heppy Pitfall, stick. It comes supplied with 4 grip pads for easier table top use. Button Blue Print, Carnival, Donkey Kong, Dorf, Mousetrap, Srnurf, Solar Vox, Turbo, Venture, Wivaid of Zaitzon: Beazer, Dracula, Ice Trek, Nova Blast, Safecracker, Swords & Serpents, Tropical Trouble, White Water. WICO STRAIGHT - STICK: The main feature of this James Bond 007, Lord of the Rings, Powys, G.Bert, Spiderman, Star Wets, Swart, Cobra. Tutankharn. joystick isits arcade style, bat handle grip. It also has 2 fire buttons. Four grip pads included for table top use. COMPUTER KEYBOARD: In July/August 1983, Mattel will be launching their new £89, 49 -key computer keyboard attachment called 'Lucky' which is fully programmable WICO TRACKBALL: A true arcade style trackball for and has microsoft basic built in. It will transform your Master Component into a home use with your Atari or Commodore VIC. This product is computer. The adaptor also accepts a 6 note polyphonic music designed to give arcade controlin your living room. synthesiser and full size 49 -key piano keyboard that will make 12' EXTENSION LEAD: A 12' extension for Atari and learning music as easy as playing games. Atari compatible joysticks for greater player freedom. MATTEL CONSOLE £85.22 + VAT = £98.00 VIDEO GAME CLUBFREE LITERATURE In a fast moving market like video games, itis difficult to keep up to date with all the developments that take place. With new programmes and accessories being introduced at a fast rate by several different manufacturers, itis impossible to get all the information you require from one manufacturer alone. Itis for this reason, that we have set up FREE LITERATURE -Please send me your FREE LITERATURE and owners clubs for the more popular video games and home computers, to keep you fully catalogues on the following items: up to date with what is going on with your particular machine. As far as we know, Silica Shop are the only company to offer such clubs, but that is not surprising since we are the specialists. We currently have FREE clubs for the Atari VCS, Atari 400/800 home computers, and Mattel I ntellivision. Soon we will have clubs for Colecovision, Aquarius OWNERS CLUB - Ialready own the following products, please enrol and Vectrex. So if you own one of these machines, fill in the coupon opposite, and we me in your FREE club: Lrill enrol you FREE OF CHARGE in the club relevant to your computer or video geme.A 01-309 1.111 'IIIIII 11111.111",1 .1.11 , 111 II" "1" ID Postcode: ZETI 0883

'11111111111'111111/141III '11111111OP '111111 ' 611111 .111111 SILICA SHOP LIMITED, Dept ZETI 0883, 1-4 The Mews, Hatherley Road, Sidcup, Kent, DA14 4DX L Telephone: 01-309 1111 or 01-301 1111

75 EDUCATIONALgm For Hi-Fi & Electronics Enthusiasts! ELECTRONIC Concept Electronics Ltd. KITS 51 Toilington Road, London N7 6PB We are the specialist of electronic kits and rack mounting cabinets. A catalogue with complete range of products including pre -amp modules, power amp modules, pre and power amplifier modules, complete kits of amplifiers, equalizers, reverberation amplifiers (with cases), alarm clocks, appliance timers, CB amplifiers, test equipment, control modules, music generator, battery fluorescent light and high quality rack mounting cabinets etc. with illustrative pictures now available at the cost of 35p + RADIO 25p p&p. KIT Professional rack mounting cabinet Panel Size Rear Box Inc VAT W H (inch)W H D £ This AM radio issupplied with building instructions plus comprehen- 19x5 17x4.5x10 23.54 19x4 17.3.5x10 21.24 sive electronic theory, exercises and test procedure. A complete 19x3.5 17x3x10 20.09 learning package, requiring only a 9V battery. 19x2.5 17x2x10 18.94 Suitable for high quality amplifiers and19x6 17x5.5x12 24.69 The largef ibreglass printed circu it board has been designed in 3 sec- many other purposes Top, bottom and19x5 17x4.5x12 23.54 tions -a TRF radio, a bass treble control and an amplifier push-pull rear cover removable for access Separ-19x4 17x3.5x12 21.24 ate front mounting plate Front panel is19x3.5 17x3x12 20.09 output circuit. Each section can be built and tested as a separate made of black anodised aluminium, the17x3.5 15.5x3x9 17.79 project. rear box is manufactured from steel pain-17x2.5 15.5x2x9 16.64 ted in black With ventilation slits and17x4 15.5x3.5x12 21.24 This comprehensive radio circuit shows an application of tuned plastic feet Heavy gauge front panel is17x3 15.5x2.5x12 20.09 circuits, I.C.'s, field effect and bipolar transistors, common emitter of brushed aluminium finish Please add £2.00 p&p per item and collector configurations, stabilizer circuits, feedback circuits, The above sizes are also available in black anodised aluminium. Front panel & rear box are both wholly made of black anodised aluminium sheets at only £4.00 complementary output stages, etc. extra per item. The radio project kit should given entertainment and interest to the novice, yet provide valuable learning material for the electrical Second Generation Class A Amplifiers student. Particularly relevant to current T.E.C. electronic courses. The price is only £1 6.70 inc. VAT + £1.50 p&p. (Allow 28 days etonly delivery). ox6- Educational and quantity enquiries welcome. MS`` Send cheque or postal order to:- TA-1020A DC CLASS A PROFESSIONAL PRE -AMPLIFIER HAZZLEWOOD ELECTRONICS LTD., TA -1000A 100W DYNAMIC BIAS CLASS A POWER AMPLIFIER Sales Department, TY-25A SUPER SPEAKER PROTECTOR TA-1020Ax1 £25.50((kit 149 Main Street, TA-1000Ax2 £55.00 k TA-1000Ax2 £55.00 (kit) Grenoside, TY-25Ax1 £6.75 k TY-25Ax1 £6.75 (kit) Sheffield, S30 3PN. Total £87.25 Total £61.75 Tel: 0742 463585 Special offer kit £69.99 + £2.50 p/p Special offer kit £49.99 + £2.00 p/p Ass £86.99 +£2.50 p/p Ass £60.99+ £2.00 p/p Send an S.A.E. to receive a list of our current electronio project kits. The above offer ends 31 August 1983 MI MEI MINI Ea Note: discount voucher not valid Price inc. VAT

1 40110111:114 Full Kits Inc. PCBs, hardware, elec- THE "INSTANT" tronics, cases (unless stated). Less SOUND BENDER Oct 81 £22.64 batteries. WATCHDOG SECURITY ALARM Aug 81 £47.06 RECHARGEABLE BATTERY extra £19.96 HANDCLAP SYNTHESISER Aug 81 £32.98 PC BOARD ZX ADC Jan 83 £34.98 WAN PHASE June 81. Less pedal E14.79 BALANCED INPUT PREAMP May 83 less case LED JEWELLERY June 81. Cross £2.99 COMPRESSOR/UM ITER May 83 less case £1014 GUITAR NOTE EXPANDER April 81 £17.98 I19.43 DRUM MACHINE Apt 81 265.97 MAX/MIN THERMOMETERApr 83 £43.78 ENGINEERS STETHOSCOPE Mar 81 £20.98 LOGIC PROBE Mar 83 less case £6.96 SOUND PRESSURE LEVEL METER Feb 81 243.1111 ALARM MODULE Mar 83 E24.57 INFRA RED ALARM Feb 81 1.59.98 DUAL LOGIC PROBE Sept 82 f14.99 4 INPUT MIXER Dec 80 £21.74 AUTO VOLUME CONTROL Sept 82 24.28 less case MUSICAL DOORBELL Dec 80 £12.77 INSULUATION TESTER May 82 METRONOME Nov 80 £6.58 HIGH OUAUTY PHONE AMPLIFIER Feb 82. ULTRASONIC BURGLARALARMAug 80 .. £29.50 MOVING COIL STAGE less case £19.79 CAPACITANCE METER Aug 80 £22.28 MOVING MAGNET STAGE less case £19.69 CMOS LOGIC TESTER Aug 80 £11.98 PEST CONTROL Feb 82 . E7.45 CLICK ELEMINATOR April 79 £67.70 Or lees case E -Z CIRCUIT..."quick. easy & reliable... the best way to make one GUITAR TUNER Jan 82 491.87 £49.98 COMPONENT TESTER Dec 81 48.78 or two -of -a -kind PC boards''! That's what "Doc" Savage (hobby CAR ALARM Nov 81 E19.77 editor, Radio Electronics magazine) says about E -Z CIRCUIT. MAGENTA ELECTRONICS LTD Official school orders welcome. Why all the excitement? EG31, 135 Hunter St., Burton -on -Trent OVERSEAS: Payment must be in sterling. Simple, E -Z CIRCUIT's exclusive 1 oz., pressure -sensitive copper Staffs., DE14 2ST. Mail Order Only IRISH REPUBLIC + BFPO - UK PRICES. Add 45p p&p to all orders. Prices EUROPE: UK PRICES + 10%. tapes & patterns apply directly to the PC board, creating an actual Include VAT. Access & Visa phone/post ELSEWHERE: WRITE FOR QUOTE. current carrying circuit. Simply apply E -Z CIRCUIT's Copper Mounting Configurations to the board. solder your components into place. and you have a professional, production quality PC board ... instantly...without artwork. photography, screening or etching. HORIZON ELECTRONICS (Midands) There's no need to worry about mistakes either. With E -Z

,.-- DeptH./E Charlotte St. Rugby Tel:78138 ..... ,.. CIRCUIT's special two-phase adhesive, you can make correc- Prime quality. TERRIFIC PRICES. Mail orderonly tions. modifications or improvements quickly & easily...without damaging the performance or appearance of your PC board. imiLtzrii 15/11/15V1 litingi.i., MBAR., 50P .0 For building. prototyping or repairing PC hoards instantly, E -Z 3312 - ;AT:- 217gpa400v 188 2.0 12p: CIRCUIT truly is the quick. easy. reliable way! CM ]558 ZENESO0 0. . TOGGLE SWITCHES , IL"" Prove it to yourself. send for your FREE copy of 13 wan 1n 2Da the E -Z CIRCUIT Copper Products Printed 'Circuit "zf&sisi, E no 6. MOMS L:4A !FATY a IN OM 3p 21: Technical Manual & Catalog EZ-3001. See why 4002 4p 285p 4004/6 5P TRANSISTORS T082002 asp "Doc" Savage & thousands of other users recom- IN 51 BC1076 Pp eu,(50 Op 5..5 13: 8C1060 BP175 5 SOLDERING IRONS mend E -Z CIRCUIT for instant PC boards. 54. 14p BC1068 10p 218176 309 Anisx C 15w 4659 25p Br257 309 131110055 ,,,..g0755:: amp 5. 20p FICC ig 33 K31) '" 809 Send for your FREE E Z CIRCUIT Printed Circuit Copper 5,20 15p 88.5 M: TOt P.: BC,' 15p BF1,68 221p LSD, Products Technical Manual & Catalog EZ 3001 2 amp 400v 38p BC182 7p BP%57 289 amp 100v 45p B22 p OFX85 28p :31:, at. 6 amp 200v 1:833; 11; .,,,,Te 38: It g;18: 90130 32 TP3251 38p 130139 p N10104 50p I, OAK sonmoSNA Ill 1313140 .218.4F 85p 4=150 1 Engineering C Electronic 1,1:2:a.g." ._ 80148 VN8BAP 55p 11t 201. TNYMSTOR8104st.c1 12p coo.,e'''' '8 = fOtt 219P Design Services Ltd. ABOVE Just a few exmples Send S.A.E /List Unit 7, Enterprise Centre, Childers Road, Limerick. ADD: 65p p&p to all orders under £5.00 VAT: add 15% VAT to total order value IRELAND Tel: ,[061 49366

76 ETI AUGUST 1983 [Ti Up until now PCBs were always the hardest component to obtain fora projecr(Aicourse yo could make your own, but why bother anymaref ra Now you can buy your boards straightfrom theglegioners- us! As oi4hisissee copyright) Pats will be avail mats r y ETI PCB Solace. E produced from the game mister usekto b our p types, so yottcan be x;and will be finighedlin the high spisicligid yr woullbegiect from ETI. in addition to the PCBs fl r this s, we aremaking available someof popular designs fmm our recent past JIM below for details. Please note that BOARDSAllAARABLE.'fig ant listed, vireglegfrhave it!

ALWAYS QUOTE THE PCB CODE WHEN ORDERING PLEASE

1979 E/819-4 Laboratory PSU 4.53O E/829-2 Dual Logic Probe 1.93 0E/794-1 Guitar Effects Unit 2.64 E/8110.1 Enlarger Timer 3.40O E/8210-1 Message Panel (2 Boards) 10.70 0E/794-2 Click Eliminator 6.64 E/8110.2 Sound Bender 2.65O E/82114 Pulse Generator 5.29 0E/796-1 Accented Beat Metronome3.60 E/8111-1 Voice Over Unit 3.97CIE/8212-1 ELCB 2.41 E/8111-2 Car Alarm...... 2.81O E/8212-2 Servo Interface (2 Boards) 5.87 1980 E/8111-3 Phone Bell Shifter 2.96O E/82124 Spectracolumn 4.82 E/803-1 Signal Tracer 227 E/8112-1 Alcohometer (2 boards). 5.21

E/808-1 CMOS Logic Tester 2.64 E/8112-3 Bodywork Checker.... 1.75 1983 E/808-3 Ultrasound Burglar Alarm .2.87 E/81124 Component Tester .... 1.49O E/831-1 Fuel G uage 3.00 E/8010-1 Cassette Interface 2.93 O E/831-2 ZX ADC 2.25 E/8010-2 Fuzz/Sustain Box 3.27 1982 O E/831-3 Programmable PSU 3.00 E/8011-5 RIAA Preamp 1.93 E/821-1 Parking Timer 2.20111 E/833-1 Sound Board 11.16 E/8011-6 Audio Test Oscillator ...3.13 E/821-3 Guitar Tuner (2 boards) .. 5.55 E/833-2 Alarm Module 3.15 E/8012-1 Musical Doorbell 2.80 E/822-1 Ripple Monitor 1.92Cl E/833-3 2X81 User Graphics ... 0.93 E/8012-3 Four Input Mixer 2.64 E/822-2 Allez Cat Pest Repeller... 1.68 E/833-4 Logic Probe 2.17 E/822-5 Moving Magnet Stage. ... 3.49O E/834-1 Real Time Clock 7.60 1981 E/822-6 Moving Coil Stage 3.49O E/834-2 Thermemeter (2 Boards).8.47 E/811-1 LED Tacho 4.13 E/8234 Capacitance Meter (2 Bd)10.14O E/834-4 Stage Lighting - Main .. 11.94 E/811-2 Multi -Option Siren 3.20 E/8245 Voltage Monitor 1.86 E/834-5 Stage Lighting - Display 3.00 E/813-1 Universal Timer 3.31 E/825-1 DV Meg 2.72O E/835-1 Compressor/Limiter ... 5.38 E/812-1 IR Alarm (4 boards)....6.64 E/825-2 Analogue PWM 3.06CI E/835-2 Single PSU 2.75 E/812-5 Pulse Generator 3.57 E/825-3 Slot Car Controller 4.51O E/835-3 Dual PSU 3.49 E/813-1 Engineer's Stethoscope. ..2.65 E/826-1 Ion Generator (3 Bds) ... 8.00 E/835-4 60 W NDFL Amp 4.70 E/814-2 Drum Machine (2 boards) .5.60 E/8264 MOSFET Amp Module. . 6.78 E/835-5 Balanced Input Preamp . 2.81 E/814-4 Guitar Note Expander ...320 E/826-5 Logic Lock 3.06 E/835-6 Stage Lighting - Autofade 5.38 E/816-8 Wee -Phase 1.53 E/826-6 Digital PWM 3.34DE/835-7 Stage Lighting - Tries E/816-9 Alien Attack 3.48 E/826-7 Optical Sensor 1.74 Board 4.12 E/817-1 System AS- Input E/826-9 Oscilloscope (4 Boards) 11.60 E/836-1 to 3 PseudoROM (3 Bds) 3.15 (MM or MC) 2.65 E/827-7 TV Bargraph Main 4.56 E/836-4Immersible Heater 2.00 0 E/817-2 System A - Preamp....5.17 E/827-3 TV Bargraph Channel . 228 E/836-5 Atom Keypad 4.50

E/817-3 Smart Battery Charger ...1.97 E/8274 Hotwire 2.63 E/837-1 Flash Sequencer...... 2.32 0 E/818-3 Hand Clap Synth 3.97 E/827-5 Bridging Adaptor 2.38 E/837-2 Trigger Unit Main Board .2.32 0 E/818-5 Watchdog Home Secuity E/828-1Playmate (3 Boards) 720 E/837-3 Trigger Unit Transmitter.1.44 (2 boards) 5.31 E/8284 Kitchen Scales 1.840 E/837-4 Switched Mode PSU ... 14.00 0 E/819-1 Mains Audio Link E/828-5 Sound Track 4.25O E/838-1 Graphic Equaliser 7.91 0 E/838-2 Servo Fail -Safe (four off) 2.55 (3 boards) 7.35 E/829-1 Auto Volume Control . . 1.84 E/838-3 Universal EPROM prog. . 8.38

What The PCB Code Means STRICLY CASH WITH ORDER- OFFICIAL ORDERS ARE NOT The first two numerals indicate the year ACCEPTED in which the project was published; the third the year. The numeral after the Prices Quoted are valid until 1st November 1983 dash uniquely identifies the board within those boards published that month. How to order: indicate the boards required by ticking the boxes and send this page, together with your payment, to: ETI PCB Service, Argus Specialist Publications Ltd, 145 Charing Cross Signed Road, London WC2H OEE. Make cheques payable to ETI PCB Service. Payment in sterling only please. Name Prices subject to change without notice. Address Total for boards PLEASE ALLOW Add 45p p & p- 0.45 28 DAYS FOR Total enclosed DELIVERY

ETI,; AUGUST 1983 TALK TO THE WHOLE WORLD Study now for the RADIO AMATEUR'S EXAMINATION Bigger and Better We have had 40 years successful experience the colourful Wilmslow Audio brochure in training men and women for the - the definitive loudspeaker catalogue! G.P.O. Transmitting licence. FREE R.A.E. brochure without obligation from: - Everything for the speaker constructor - kits, drive units, components for HiFi and PA. IBritish National Radio 8 Electronics SchoolI 50 DIY HiFi speaker designs including the exciting new READING, BERKS. RG1 1BR dB Total Concept speaker kits, the Kef Constructor range, Wharfedale Speakercraft, etc. IName Flatpack cabinet kits for Kef, Wharfedale and many others. IAddress * Lowest prices - Largest stocks * * Expert staff - Sound advice * LET1/13/81 7 BLOCK CAPS PLEASE. j * Choose your DIY HiFi Speakers in the comfort of our * two listening lounges (Customer operated demonstration facilities) SPEAKERS * Ample parking * MULTIMETERS (Hi-Fi, P.A., Disco, Bass Guitar) (UK C/P 65p) Send 1.50 for catalogue RANGE DOUBLER 10A DC1 8" 60W... £11.95 (cheque, M.O. or stamps - or phone with your credit card number) Special price £15.95 10" 50W... £12.95 ETC 5000/5001 121 Ranges * Access - Visa - American Express accepted * 12" 100W... £26.95 also Hifi Markets Budget Card. 50K/V Range Doubler 10A DC £16.50 18" 100W... £39.95 TMK 500 23 Ranges 30K/V 12A MOTOROLA PI EZO DC Plus cont. buzzer £23.95 TWEETERS IN STOCK NH56R 20K/V 22 Range Pocket RETAIL MAIL ORDER 0625 529599 £10.95 360TR 23 Range 100K/VLarge EXPORT INDUSTRIAL scale 10A AC/DC plus Hfef36.95 EDUCATIONAL 35/39 Church Street, Wilmslow, Cheshire SK9 1AS ATI 020 18 Range 20K/V. DeLuxe Order by Post FREE plus Hfe Tester £17.50 with cheques, ALL PRICES CATALOGUE Access/Visa or Lightning service on telephoned credit card orders! ST303TR 21 Range 20K/V plus HfeYou can INCLUDE SEND LARGE Tester £16.95telephone your SAE orders. VAT (UK 20.

MUSICRAFT 303 EDGWARE RD, LONDON W.Z. TEL: 01-402 9729 2898

PARNDON ELECTRONICS LTD. Dept. 23, 44 Paddock Mead, Harlow, Essex. CM18 7RR. Tel: 0279 32700 1 MODULAR AUTOMATIC£24.50 RESISTORS: Vi Watt Carbon Film E24 range ± 5% tolerance N EW:TELEPHONE SYSTEM 1+£1 p&p Bandoliered and colour coded. Full Range IR010M. Each ready built module is a complete exchange f1.00 per hundred mixed (Min 10 per value) £8.50 per thousand mixed (Min 50 per value) providing up to ten extension lines Special stock pack 60 values. 10 of each £5.50 * Simply connect 'phones and power supply * Only two wires to each telephone 1 AMP 31/2 Digit LCD Display: 1 , 3 decimal points * Uses ordinary dial or push-button 'phones VOLT REG plus/minus sign and lo bat indicator. * Complete privacy for conversations + ve 5v, 12v. Complete with low power 7106 A/D converter display driver. * Range of several miles 15v, 24v - £0.40 Driver set £8.95 * Fully expandable system -ve 5v. 12v Display £3.50 Driver £6.50 15v - £0.43 Each module allows two 'phones to be used at one time, DIODES: IN4148 £1.60 per hundred two modules allows four, etc.

8 pin - 10p. 14 pin - Ilp. 16p pin - 12p. 18p pin -19p. 20p pin -21p DIL RECONDITIONED TEMPERATURE GUAGE 0-120°C SOCKETS 22 pin - 23p. 24 pin - 25p. 28 pin - 27p 40 pin - 42p. TELEPHONES Remote sensor on 38" capilliary, panel mounting dial Push Button TrImphones £15 55mm. dia. Only £2.50 Full List Available - Send SAE + £1.80 p&p. 2for £28 + ALL PRICES INCLUDE VAT. & POST & PACKING - NO EXTRAS £2.50 PushButton 746 £9.75 + 16A 240V RANCO THERMOSTAT MIN ORDER - UK £1.00 OVERSEAS £5 CASH WITH ORDER PLEASE £1.80. 2 for £18 + £2.50 Wide control range (low room temp. to over boiling point). Same Day Despatch Recent StyleDial Phones Sensor on 22" capillary. 2.30, including control knob £4.75 + £1.80. 2 for £9 + £2.50. 5 for £20 + £5 Seconds(ingood working BUY ONE EACH OF ABOVE FOR £5.50 order) Class 1 £3.50 + £1.80. 5 for £15 + £5 Class 2 (discoloured) £2.25 + GEAREDSynchronousmotor,8 r.p.m.240VA.C.3Watt CENTRONICS 306 £1.80. 5 for £9 + £5 £2. LINE PRINTERS

SOLENOID GAS VALVE. 240V A.C, 5 P.S.I. suitable for UNISELECTORS. 50v, 4 Bank non -corrosive fluids. £2.20 - Homing Bank, 25 way £3.50 Visual Display Units Burroughs MT686 VDUs BULGIN 3 pin free plug & panel socket. 2A 240V Theseversatile micro Desk -top Ten Way Manual Ex- 50p controlled programmable professional fast FLOPPY DISC DRIVES change (key & lamp unit) terminalshave 3 RCA compact line -printer. 80 with instructions £8 + £1.80 P&P 1802 CPUs and 64K of columns, 120 char/sec. Fantastic MEMOREX Parallel 550 8" discs mounted in DIAL -OUT WITH YOUR COMPUTER. PCB.'s convert memory. 12" Green i/f. Quality at a binary to dialing pulses and enable your computer to attractive case with screen 180 x 25) RS232. silly price. Vertical format Send S.A.E for free leaflet on dial -out(withsuitableinterface).Ex -equipment. 106 key detached key- unit. To inc. operations power supply and fan. telephone systems. Tested. £12 with explanatory notes. board. Can also be used manual. ONLY £149.00. Shugart standard 50 way as quality video monitor. Carriage (England) interface. Space for £149 + £15 carr. WHILE £17.50. Tech manual second drive. £199 (cam STOCKS. LAST. 1230 pages) £10.00. £9.50). L.E.M: SERVICES ADD 50p P&P 22Emscote Road, ORDERS OVER Warwick,W MAWSON ASSOCIATES Warwickshire £7.50 POST FREE 124 Lennard Rd, Beckenham, Kent BR3 1QP unless stated otherwise Tel: 0926 490740 WE ALSO BUY COMPUTERS 01-7783600 Callers welcome by appointment AND COMPUTER PERIPHERALS s/h items sold working but not greed ALL ITEMS - MONEY BACK IF NOT DELIGHTED

78 ETI AUGUST 1983 AVON PROGRESSIVE RADIO WARWICKSHIRE 93 Dale Street. Tel 051 236 0982 ANNLEY ELECTRO 47 Whitechapel, Tel 051 236 5489 /--kORCZON Liverpool 2 190 Bedminster Down Road TIE ELECTRONICS SPECIALISTS' LECTRON1CJ. Bedminster Down, Bristol Open: Tues-Sat 9.30-5.30 Charlotte St, Rugby. Tel: Rugby 78138 Tel; 0272 632622 - Open: Mon -Sat lam -6.30 pm Wed Sam-2pm Open 5 Days 10-6 (closed Wed) Wide range of components and R.S. stockists 1983 Mail Order Catalogue 75p NORTHAMPTONSHIRE LANCASHIRE WORCS/W. MIDLANDS * A NOW company sallies electronic cern00000 ts. * Mail order andwalk- market. MESON ELECTRONICS * Vest stocks and very competitive prices. %11111111/ RANI Of 15B Lower Green, sNigh March, 00000 try. NNI1 4AQ. 103 Coventry St., Kidderminster 111Poulton-le-Fylde, Blackpool Tel eeeeee 03272 5523. Telex 311245. Components, computers, car radios, Tel: 10253) 885107 /iv* Mt A45 eeeee ite John 0' taint.) C.B.'s, amateur radio Open: 9.30am-12.30. 1.30-5.30. Closed Wed & Sun. Spares & Repairs Electronic Component Specialists. Open: Mon -Sat 9-6, TEL: 0562 2179 S. WALES MERSEYSIDE YORKSHIRE STEVE'S ELECTRONIC MYCA ELECTRONICS SUPPLY CO. LTD. ACE MAILTRONIX LTD. 2 VICTORIA PL, SEACOMBE FERRY, WALLASEY, L44 6NR. 45 Castle Arcade, Cardiff 3A Commercial Street, Tel: 051 638 8647 TEL: 0222 41905 Batley. Tel: (0924) 441129 Open Mon -Sat 10am-5.30pm Open: Mon -Sat 9-5.30 Mail Order price list 50p refundable OpenMon -Fri gam-5.30pm. (Sat 1pm( For components to computers Retail and wholesale.

WHY WRITE TO LONDON When you can walk to the Midlands largest JUST OUT selection of DIY. Plugs, sockets, connectors, cable, flex, leads, boxes, Aerials, styli, components, elements, OUR NEW CATALOGUE semi -conductors, meters. Presented with a Professional Approach and Appeal to In fact the lot! ALL who require Quality Electronic Components, Spares and repairs for all electronic, electrical Semiconductors and other Accessories ALL at realistic and audio. prices. There are no wasted pages of useless information so H. G. Electronics Co. often included in Catalogues published nowadays. 1350 Stratford Road, Hall Green, Just solid facts i.e. price, description and individual Birmingham B28 9EH Qz-L features of what we have available. But remember, Telephone: 021-777 2369 BI-PAK's policy has always been tosellquality components at competitive prices and THAT WE STILL DO. We holdvastStocks"in stock"forfastimmediate delivery,allitemsinour Catalogue are available ex stock. The Catalogue is designed for FREE BOOKLET use with our 24 hours "ansa- phone" service and the Visa/ on Access credit cards, which we accept over the telephone. BURGLAR ALARMS Toreceiveyour NEW 1983 with BI-PAK Catalogue, send 75p LOWEST U.K. DIY PUBLISHED PRICES PLUS 25p p&p to:- PHONE OR WRITE FOR YOUR COPY AIL 051-523 8440 11. Ws twro AD ELECTRONICS Access & VISA accepted 217 WARBRECK MOOR RI 509203182 for ac BI-PAK"" Immedlate despatch AINTREE, LIVERPOOL L9 OHU ETI AUGUST 1983 79 ELECTRONICS TODAY INTERNATIONAL CLASSIFIED

Lineage: 01-437 1002 350 per word (minimum 15 words) 1E3 EXT 282 Semi Display: (minimum 2 cms) Send your requirements to: £10.00 per single column centimetre Julie Bates, Ring for information on series bookings/discounts ASP Ltd., All advertisements in this section must be prepaid. Advertisements are accepted subject to the terms and 145 Charing Cross Road, conditions printed on the advertisement rate card (available on request) London WC2H OEF

FOUR OLIVETTTI TE. 300 FOR SALE input/output terminals. In- VALVES EQUIPMENT tegral 8 hole paper tape punch and reader. 110 Baud Standard EX -GOVT VALVE and Semi- ASCII serial input/output. 120 conductor Equivalents Guide. CABINET FITTINGS columns untested, unguaran-Contains an up to date fully teed. Buyer to collect, £40 comprehensive crossrefer- each.Mr.A.J.Stitchman, enced guide to British and Chesterfield College of Tech-American Service valves and nology, Infirmary Road, Chester- semiconductors. £2.50 plus pp field (0246) 201011, extension 30p. Valve List. Valves from Printed Circuit Boards 337. 1925 to 1980. Many obsolete to your specification types. Modern TV, radio and from artwork through to transmitting valves. Send 60p finished board. PLANS 'N DESIGN (refundable on purchase). Or free with Ex -Govt., Valve Guide. We sell valves ofall types. AMAZING ELECTRONICS Please send SAE for your re- PLANS. Lasers, super -powered quirements. Dept. ETI Myers cutting rifle,pistol, light show, Electronic Devices. 12/14 ultrasonic force fields, pocket Harper Street, Leeds LS2 7EA. defence weaponry, giant tesla, Adam HaII,F I Suppl,es) Tel: (0532) 452045. Ur,t B Carlton Court. Grange, Road satellite TV pyrotechnics, 150 Southend on Sea more projects. Catalogue £1 (refundable)fromPlancentre, AERIALS ELECTRONIC ORGAN KEY- Bromyard Road Industrial BOARDSand other parts being Estate, Ledbury HR8. AERIAL BOOSTERS. cleared out as special offer. NEXT TO THE SET FITTING. B45H/G-UHFTV. Gain about 20 dbs. 35 Grosvenor Road, Elvins Electronic Musical CONVERT any TV into large Tunable over the complete UHF TV Twickenham, Middlesex Instruments, 40A Dalston Lane, screen oscilloscope. External band. Price £8.70. TEL:01.8911923/1513 Telex:29509 London E8. 01-986 8455. unit plugs into aerial socket of BR-VHF/FM RADO. Gainabout 14dbs. When on the off position con- TV. Circuit & plans £3 or S.A.E nects the aerial direct to the radio. SHEETMETAL FOLDERS 18" details. J. Bobker, 29 Chadder- Price £7.70. COPPER CLAD double sided x 18c Steel, 16G Aluminium tonDrive,Unsworth,Bury, All boosters we make use a PP3/006p/ fibreglass, 12" x 18". 10 sheets bench or vice held. Hobby or 6F22 type battery or 8v to 18v DC. Lancs. P&P 30p per order. £6.50, -5 sheets £4.50, - 20 Lightindustrial use. £38. Electronic Mailorder Ltd sheets £10.50. Davron, 1In- 01- 890-7838. Day/evening. 62 Bridge St., Ramsbottom, dustrialUnit,Parker Road, HARDWARE Lance, BLO 9AG. 1000 16 PIN WIREWRAP Tel: (070882) 3036 Chelmsford, Essex. SOCKETS, gold plated £3 for Access/Visa Cards Welcome, sae leaflets BURGLAR AlarmEquipment. 10, £25 for 100. 75 ITT lever COMPUTER SPARES Please visit our 2,000 sq.ft. switches, gold contacts eg. 4 POWER SUPPLIES EXHIBITIONS showrooms or write or phone for c/o + 4 c/o 3 way 60p, 2 c/o 1 BBC MICROCOMPUTER PSU MOD your free catalogue. C.W.A.S. way 40p. Miniature DP centre D1597 Ltd., 100 Rooley Avenue, Brad- off 40p. Some TTL eg. 7400 8p, 240V ac 30W. Outputs - 5V dc 100 ma, + SUSSEX MOBILE RALLY. A 5V dc 2.25A Conform to BS415. £10.00 ford BD6 1DB. Telephone 7474 14p, 74121 20p. Phone: + £2.00 p&p + VAT. day by the sea with the family RACAL MILGO EX EQUIP for £1. Brighton Raceground. 0274 308920. 0477 32754 evenings. POWER MODULE MOD 001 240V ac Input. Outputs:- 2 x +5V dc, 1 x 17th July. 10.30 am - 5.00 pm. FOR SALE. Acorn Atom 12K A LASER for£125. Complete in -12V dc, 1 x +12V dc. Free car parking. Good cater- Rom. 12K Ram. Sony Cassette cabinet with power supply. £25.00 + £2.95 p&p + VAT. ing under cover. MAINS ADAPTORS Recorder and games programs Send 50p for details, plus infor- INGERSOLL MOD XK2598 £110. Telephone 01-568 4254. mation regarding other Lasers, Output 9V dc 500ma, 4 metres twin lead to 2.5mm jack. Conforms to BS415. COMPUTERS Holograms available new £3.00 + 75p p&p + VAT. RS232 CABLES and D -type andex-exhibit. D.H.S. Develop- (Other typOs available S.A.E. for list). connectors at competitive ments, 21Grosvenor Road, VULCAN NL CAD CHARGER MOD V92 CORTEX COMPUTER with Charges 8aa cells and 4aa cells. £5.00 + RS232 working fast and power- prices. 25 -way D connector Scarborough. 75p p&p + VAT. ful. £310. Phone Mr Hill, Mid- plate/wallbox for only £5.25. PERSONAL STEREO FM/AM IMP PRINTER KITS hurst 3632 after 7pm. Write or phone for details. VEP To enable building of complete printer Limited, 5 Hewens Road, Ux- radio + headphones. Superb (no main board components or top cover included). Kit consits of: For All ETI Classifieds bridge UB10. Tel: 01-848 7207. tone. Fully guaranteed. Only Imp main drive, base plate, transformer, £12.95.TaitsMailOrder, ribbon cable, capacitor, switch assembly, Tel: 01-437 1002 31 Lime Grove, Addlestone, printer PCB (unpopulated) plus circuit ext 282 diagrams and connection instructions. Surrey. Free Nascom 1 PCB & 8 amp PSU PCB WANTED with each order received before end of August. £55.00 + £5 p&p + VAT. Some WIRES 'N CABLES 300 WATT SLAVES £15 E/E!! discrete components available for printer ...Illustrated leaflet. S.A.E. KIA- PCB. S.A.E. for details. WANTED: ELECTRONIC LONDEX TIMER STP-NR SUB MINY 8, Cunliffe Road, Ilkley. 120 110V ac 0-215 seca£10.00 +£1.00 p&p THE SCIENTIFIC COMPONENTS and test equip- Watt, case + sliders £10.85. + VAT. WIRE COMPANY ment. Factories cleared. Good OMRON MIN PCB RELAY. LCIN-E 48V 811 Forest Road, London E17 dc SPCD 50p + 25p p8 p + VAT. 01-531.1568 prices given. Q Services, 29 TEKTRONIX SCOPES £110, 4 WAY POWER Plug -Consists 2.5mm or ENAMELLED COPPER WIRE Teletypes £80. Free leaflet: - 3.5mm jacks.Plus 2.1mm x 2.5mm SWG llb 8oz 4oz 2oz Lawford Crescent, Yateley, power -in plugs on 2 metre lead. e1 .25 + 8-34 3.63 2.09 1.10 88p James Sinclare, 82 Plumstead 25p + VAT. 35-39 3.82 2.30 1.26 93p Camberley. Common Rd., SE18. 01-316 4 WAY DIN SOCKET on 1.5 metre 4 core 42-43 5.20 2.91 2.25 1.60 1779. lead. £1 .00 + 25o + VAT. 44-47 8.56 5.80 3.49 2.75 48 15.96 9.58 6.38 3.69 TURN YOUR SURPLUS tran- SILVER-PLATED COPPER WIRE MAPLIN 3800 SYNTH. Fully Trade enquiries on all above welcome. 14-30 9.09 5.20 2.93 1.97 sistors, IC's etc into cash. Con- completed and tuned, plus in- TINNED COPPER WIRE tact Coles Harding & Co., 103 Dlonics, 17 Hawkesworth Drive, 14-30 3.97 2.41 1.39 0.94 South Brink, Wisbech, Cambs. ternal speaker and manual. Kenilworth, Works. Prices include P&P and VAT.Orders under £250. Tel: Christchurch Tel. 0926 59658 Tx. 312440 £2 add 20p. Dealer inquiries welcome. Tel: 0945 584188. Immediate 478935 evenings. settlement. 80 ETI AUGUST 1983 COMPONENTS ALARMS

DO YOU WISH TO LEGALLY 051.728 3483 CENTURION TRANSMIT AUDIO SIGNALS OVER INTRUDER ALARMS LTD WHOLESALE SUPPLIES ALARMS BRITISH TELECOM CIRCUITS? Al MAIL ORDER DEPT We manufacture, We manufacture approved Interface Equip- Bell Boxes £6.00 ment for NARROW or WIDE BAND PRIVATE Dummy Boxes £4.50 you save £ £ C's Bell 6" £7.50 WIRE and PUBLIC SWITCHED TELEPHONE SIRENS Send s.a.e. or phone for our NETWORK circuits. Minimite £4.50 Free listof professional Also TELECOM LINE CIRCUIT SAFETY Electronic £7.50 D.I.Y. Burglar Alarm Equip- Cable (4 core) £7.00 ment and accessories. BARRIERS. PRESSURE MATS Stair £0.95 Discount up to 20% off list PARTRIDGE Standard £1.50 prices, eg. Control Equip- 56 Fleet Road, Benfleet, CONTROL PANELS ELECTRONICS Essex, SS7 5JN, England. Battery T/E/E £20.00 ment from £15.98, Decoy The Mixer People F.S.N. 20/40 £36.00 Bell Boxes from £5.95 inc. (Telephone 03745 3256) CONTACTS Aluminium £1.85 Surface £0.75 BURGLAR ALARM EQUIP- TRADE ENQUIRIES WELCOME MENT: As used in the trade. JN Flush £0.65 Security Centre, 176 Syden- Quickfits £0.75 g',D 0484-21000 BEAMS or 0484 35527 (24 hr. ans./ ham Road, London SE26 5JZ. Infra Red CENTURION ALARMS (ETU 01-778-1111. Showrooms £31.50 Ultrasonic comp £36.00 265 Wakefield Road, Huddersfield open six days. Rec Battery £6.95 E3HD598E. W.t),orkshireA,OUR Orde'rseWskor:d MAIDSTONE ELECTRONIC DRopunt on quantity - Maw add MR COMPONENTS shop.Thy- VAT ronics. Control Systems 8, San- FOR ORDERS LESS THAN DR PEP CLIO BOOKS & PUBLICATIONS OVER ER PRP FREE dling Road, Maidstone, Kent, Al ALARMS LTD Maidstone 675354. SE Derby Lane, Old Swan, Liverpool 13 PARAPHYSICS JOURNAL (Russian translation); psycho- KITS tron ics,kirlianography,hell - Developer 35p. Ferric Chloride phonic music,telekinetics. 60p. Clear acetate sheet for Computer software. S.A.E. DIGITAL WATCH REPLACE- master 15p. Copper -clad MENT parts, batteries, displays, fib- 4x9",Paralab,Downton, reglassboard,approx. 1mm Wiltshire. backlights etc. Also reports pub- thick £2.00 sq. ft. Post/packing lications, charts. S.a.e. for full list MANUALS for test and com- 75p. White House Electronics, munications equipment. Send Profords Conersdrive, Holmer- Castle Drive, Praa Sands, Pen- green Bucks. HP15 6SGD S.A.E. for list. P. Mack, 14 Court 256K BUBBLE MEMORIES. zance, Cornwall. Eight, Hemingway Road, Interface details included. Only PRINTEDCIRCUITS Make your Witham, Essex CM8 2QU. £7.50 each. own simply, cheaply and quickly! Phone ASP boards. Very high quality. £45 Golden Fotolac light-sensitive BOUND E.T.I.'s Jan. 1977 to each. Fare11, 78 Glenf ield Road, Dec. 1982. £13 each com- Paisley. SAE. Tel: 041 884 laquer - now greatly improved Classified plete year plus p&p. Phone 6240. and very much faster. Aerosol (0252) 511048 after 6pm. No cans with full instructions, £2.50. 01-437-1002 splits. CLASSIFIED ADVERTISEMENT- ORDER FORM Advertise nationally in these columns to over 100,000 readers for only 35p per word (minimum charge 15 words). Simply print your message in the coupon and send with your cheque or postal order made payable to Argus Specialist Publications Ltd to: CLASSIFIED DEPT., ELECTRONICS TODAY INTERNATIONAL 145 Charing Cross Rd., London WC2H OEE. Telephone: 01-437 1002 Please indicate classification required.

Name Address

Tel. No. (Day) WE TAKE ACCESS AND BARCLAYCARD Please place my advert in E.T.I. for 0 months. Please indicate number of insertions required.

ETI AUGUST 1983 81 WHAT USE A MICRO E.T.I. AUGUST 1983 ADVERTISERS INDEX WITHOUT A PRINTER?

A.D. Electronics 79 Aitken Bros 59 Ambit International 37 Armon Electronics 59 Audio Electronics 27 Bi-pak 79 BK Electronics 8 Black Star 57 BN RS 56,78 NEW A.D.M. 80 COL. DOT MATRIX WITH Bradley Marshall 36 TRACTOR FEED. BACKED BY ONE OF Clef Products 6 BRITAINS LARGEST MANUFACTURERS, IT IS Comtech Electronics 6 NOW STOCKED BY US. Comquip Electronics 64 SPECIAL LAUNCH PRICE Concept Electronics 76 £311.00 +VAT. Carriage £7.50 or collect from Cricklewood Electronics 22,23 our warehouse. Crimson Elektrik 56 Crofton Electronics 82 CROFTON ELECTRONICS LTD. Display Electronics 12 35 GROSVENOR ROAD, TWICKENHAM, MIDDX 01891 1923/1513Telex 295093 Electronize Design 14 Electrovalue 27 Engineering & Electrical Design ....76 Greenbank 69 Hawk Electronics 64 Hazzlewood Electronics 76 H.G. Electronics 79 Horizon Electronics 76 House of Instruments 60 ICS 69 I LP 28, 29, 57 Kelan Engineering 7 Kempston Electronics 82 L.B. Electronics 27 L. E. M Services 78 L. & M. Services 52 Magenta Electronics 76 Maplin OBC Mawson Assocs. 78 Midwich Electronics 63 Musicraft 78 Pantechnic 60 Recognises WST and LPRINT which allows programs to be listed directly from your Spectrum Parnden 78 Also allows printout direct from BASIC listings without the need for IFC, 10, IBC special user calls Powertran Completely self contained with I metre of ribbon cable and connectors Rapid Electronics 21 Works with any Centronics Interface including all Epsons, Seikosha 100A, OKI Microline 80 etc R.T.V.C. 7 Includes driving software which allows up to 128 characters per line Spa rkrite 75 Full range of business software available Fully tested and guaranteed for 12 months Trade Er>gviriei Stewarts of Reading 6 Plus L140 P + P Tangerine Computers 44 Technomatic 16,17 T K Electronics 38 Watford Electronics 4, 5 Wilmslow Audio 78 82 ETI AUGUST 1963 Get moving with thesenew developments in UK Robotics - advanced electrohydraulic designs for education, industry and now available to the home constructor.

Hebot IIis a turtle -type robot which takes programming Robotic experience is becoming as essential a subject as computing. out of the two dimensional world of the VDU into the real MICROGRASP provides the lowest cost means of acquiring that three dimensional world Given a DC supply of 9-15V it can experience but despite its ultra low price the robot has considerable perform a bewildering number of moves under computer versatility There are 5 axes each using a servo motor and there is control - forwards. backwards. left and right - with each feedback from each of the arm movements. Controlis by any wheel independently controlledIt has blinking eyes. bleeps computer wish an expansion bus - the ZX81 being particularly suitable. with a choice of two tones and has a solenoid operated pen to Servoing is iichieved with hardware on the interface board to keep chart its progress Touch sensors coupled to its shell return programming simple and the robotisoperated under BASIC data. about its environment. to the computer for it to calculate commands with no computer specific software required. The interface evasive or exploratory action. Hebot II connects directly to board is memory mapped using only 64 bytes at any of 1024 switch an I/O port or alternatively with the universal interface board selectable locations to the expansion bus of a ZX81 or other computer MICROGRASP robot kit with power supply 145.00 Universal computer interface board kit £48.50 23 way edge connector £2.50 ZX81 peripheral /RAM Pack splitter board £3.00 MICROGRASP, INTERFACE BOARD AND ZX81 printing, call to machine code routines, hexadecimal support and user- friendly textual error trapping messages. If computers interest you then the Cortex will expand your under- standing infinitely more than off the shelf machines. Use itin business, education, research or just play with the incredible graphics capability. At Powertran we are using these machines in HEBOTT II conventional roles, in product control and R & D. We shall co- ordinate the Cortex user group and distribute software for the Up to the nano -second hard, firm and softwar TMS 9995 CPU. Complete 16 bit 64K computer kit £295.00 + developments embodied in a complete system. 1 VAT. Complete 16 bit 64K computer ready built £395.00 + VAT. Mega Hertz 16 bit CPU; 64K upwardly compatibl DRAM; separate 16K video DRAM and 24K TI Powe Basic with overwrite. Supports up to four Disc drives o mixed type with 16 serial I/O ports. Programmable Baud rate and comprehensive E Bus interface designed to support real world applications. Very high resolution graphics gives 3D simulation in 16 colours on 36 prioritised planes of user definable characters. Software FORTH coming includes this trendy language along with NOS C/PM. Hardware components available separately with details in Nov, Dec, and Jan issues of ETI. Software features include; Real time clock, full renumber command, buffered I/O to free machine whilst

Top of the range is the Genesis P102 which has dual speed Example prices and With prices starting below £1.000 the Genesis range of general purpose robots control,continuous servo operation and double acting specifications provide a first rate introduction to robotics for both education and industry. Each has a self-contained hydraulic power source. which enables loads of cylinders for increased torque on the wrist and arm rotation Genesis S101 Base 19.5" x 11" x 7 5" several pounds to be smoothly handled. The system operated from a single joints. The microprocessor based control system has addi- Lifting capacity 1500gm phase 240 or 120V AC supply or a 12V DC supply. The machine can be supplied tional memory, position interrogation via the RS232C inter- Arm lift 66" with up to 6 axes each of which is fully independent but capable of simultaneous face increasing the versatility of computer control and inputs Weight 29Kg operation. Position control is achieved by means of a closed -loop feedback 4 axis model in kit form E425 system based around a dedicated microprocessor. Movement sequences can are provided for machine tool interfacing. 5 axis model in kit form E475 be entered. stored and replayed by use of a hand held controller, alternatively the 6 axis system READY BUILT £1950.00 systems can also be interfaced to an external computer via a standard RS 232C Powertran CORTEX 16 bit 64K computer K't £295.00. READY BUILT £395.00 link Genesis P101 (Electronics Today International December issue on CORTEX) Base 19.5" x 11" x 7 5" Lifting capacity 2000gm Arm lengths between axles 14 0" Weight 34Kg 4 axis model in kit form £675 6 axis model in kit form £595

Complete Systems as shown in Photograph above Genesis 5101 4 axis system in kit form £681.50 5 axis system in kit form £737.50 5 axis system Ready Built E1450 Genesis P101 6 axis system in kit form £945.00 6 axis system Ready Built £1650

All prices exclusive of VAT

GENESIS P102 PROCESSOR BOX, HAND HELD CONTROLLER AND CORTEX COMPUTER GENESIS S101 AND GENESIS P101 WITH PROCESSOR BOXES AND HAND-HELD CONTROLLERS

WORLD LEADERS IN ELECTRONIC KIT DESIGN AND SUPPLY (CYBERNETIC DIVISION) PORTWAY INDUSTRIAL ESTATE ANDOVER HANTS 1010 3NM Phone 5m:with's (02641 64455 Export Enquiries Powertran International Hollom Down Farm Lopcombe Salisbury WiltshireSP5 1BP Tel:0264 781545 TLX: 477407ZENMON Send now for an appli- cation form - then buy it map with MAPCARD. MAPLIN prmleged account MAPCARD gives you real spending power - up 56790713 NI SMITH to 24 times your monthly Dm, Dam NOV 79 payments - instantly! Maplin News

Sole UK Agents GREAT PROJECTS Computer forHeathkit FROM E&MM Shopping NOW THE world-famous Heath - kit range of superb electronic kits Arrives is available from Maplin - the newlyappointedexclusive UK AS FROM June 1st you can distributor.Kits range from a place orders directly with our simple clock for beginners to a computer from your personal unique Robot (see pic) with which computer. The computer shop- you can learn about robotics. OUR NEW book "Best of E&MM ping revolution has arrived! To There is a range of training Projects Vol. 1" brings together 21 communicate,you'llneed a courses covering electronics and fascinating and novel projects from modem (our RS232 compatible computing topics, many contain- E&MM's first year. modem kitis LW99H price ing constructional projects. For Projects include Harmony Gen- £39.95) and an interface (our full details, pick up a copy of the erator,GuitarTuner,Hexadrum, ZX81interface LKO8J price Syntom, Auto Swell, Partylite, Car £24.95 is available already with latest Maplin magazine or write Aerial Booster, MOS-FET Amp and for a free copy of our Heathkit other musical, hi-fi and car projects. many more for most popular catalogue. Order As XH62S. ORDER AS XH6 I R. PRICE £1. micros coming soon). Just dial us up on 0702 552941 and you'll be able to interrogate Maplin's Fantastic Projects our stockfile then place your -MI order, type in your credit card MAPLIN number and a few minutes:after FULL DETAILS in our project Controller Panic Button for ONE EMIL you hang up your order will print books. Price 70p each. on Home Security System Model out in our warehouse ready for In Book 1 (XAO1B)120W rms Train Projects Timer for Ex- packing. And all without saying MOSFET Combo -Amplifier ternal Sounder. a word. Universal Timer with 18 program ai In Book 6 (XAO6G)Speech times and 4 outputs Tempera- r,van Try out the future way of Synthesiser for ZX8I & VIC 20 shopping now!You'llsee im- ture Gauge Six Vero Projects. -- FOUR Module toBridge two of our mediately what stock we've got In Book 2 (XAO2C)Home MOSFET Amps to make a 350W available and you'll discover how Security System Train Control- Amp ZX8 I Sound on your TV ler for 14 trains.on one circuit easy itis to ensure your order is Scratch Filter Damp Meter exactlyright.And you'llsee Stopwatch with multiple modes Four Simple Projects. precisely what the current price is Miles -per -Gallon Meter. In Book 7 (XAO7H)Modem for each item and what total In Book 3 (XAO3D)ZX81Key- Interface for ZX8I/VIC20 Digi- amount will be charged to your board with electronics Stereo 600MHz Ultrasonic Intruder tal Enlarger Timer/Controller credit card. It all helps to make 25W MOSFET Amplifier Dop- Detector I/O Port for ZX8I DXers Audio Processor Sweep buyingeasier.So liveusa pler Radar Intruder Detector Car Burglar Alarm Remote Oscillator CMOS Crystal Cali- ring now! Remote Control for Train Con- Control for 25W Stereo Amp. brator. troller. In Book 5 (XAO5F)Modem to In Book 4 (XAO4E)Telephone European standaid 100W 240V Exchange for16 extensions AC Inverter Sounds Generator

FrequencyCounter10Hzto forZX8I CentralHeating MATINEE ORGAN EASY -TO -BUILD,superb specifica- tion.Comparable with organs selling 25W Stereo for up to £1000. Full construction details' in our MOSFETAmplifier book (XH55K). Price £2.50. Com- *Over 26W/channel into 85t at wires (plus toroidal transformer pletekitsavailable. Electronics 1kHz both channels driven. and mains lead terminations). (XY91Y) £299.95*. Cabinet (XY93B) * Frequency response 20Hz to *Complete kitcontains every- £99.50*. Demo cassette (XX43W) 40,kHz ± 1dB. thing you need including pre - £1.99. Carrtazr ettra *Low distortion, low noise and drilled and printed chassis and high reliability power MOSFET wooden cabinet. output stage. Full dptails in Projects Book 3. MAPLIN ELECTRONIC SUP- *Extrqinely easy to build. Almost Price 70p (XAO3D). Complete kit Maplin's New PLIES LIMITED, P.O. Box 3, evtrythingfitson main pcb, only £55.20 incl. VAT and car- 1983 Catalogue Rayleigh, Essex SS6 .8LR. Tele- phone: Sales (0702) 552911 cuttinginterwiringto just7 riage (LW71N). Over 390 pages General (0702) 554155. packed with Shops at: 159 King St., Ham- POST THIS COUPON NOW! Name dataantipic- mersmith, London W6. Tel: 01-748 PleaSe send me a copy of your tures and all 0926. 284 London Rcl., Westcliff- 1983 catalogue. Ienclose £1.50 Address completely on-Sea, Essex. Tel: (0702) 554000. (inc. P&P). If I am not completely revised and in- Lynton Square, Perry Barr, Birm- satisfiedI may return the cata- cluding over ingham. Tel: (021) 356 7292. logue to you and have my money 1000 new items. refunded. If you live outside the Shops closed Mondays. On sale in all branches All prices include VAT & carriage. UK send £1.90 or 10 International of Post Code WH SMITH. Price £1.25. Please add 50p handling charge to Reply Coupons. orders under£5total I. 7lue.