Silicon ChipMarket Centre - December 1990 SILICON CHIP
  1. Outer Front Cover
  2. Contents
  3. Publisher's Letter: The CD/Green Pen Story: getting to the truth of the matter
  4. Feature: Understanding PC Memory by Brian Richards
  5. Feature: The Great Green CD Pen Controversy by Leo Simpson
  6. Project: DC-DC Converter For Car Amplifiers by John Clarke & Greg Swain
  7. Project: The Big Escape by Darren Yates
  8. Serviceman's Log: It sounds like Donald Duck by The TV Serviceman
  9. Project: Wiper Pulser For Rear Windows by John Clarke
  10. Order Form
  11. Vintage Radio: Old radio books & magazines by John Hill
  12. Project: Versatile 4-Digit Combination Lock by Gary Ioppolo
  13. Feature: Computer Bits by Jennifer Bonnitcha
  14. Back Issues
  15. Feature: The Story Of Electrical Energy; Pt.6 by Bryan Maher
  16. Feature: Amateur Radio by Garry Crattm VK2YBX
  17. Feature: Remote Control by Bob Young
  18. Feature: Index to Volume 3
  19. Market Centre
  20. Advertising Index
  21. Outer Back Cover

This is only a preview of the December 1990 issue of Silicon Chip.

You can view 58 of the 120 pages in the full issue, including the advertisments.

For full access, purchase the issue for $10.00 or subscribe for access to the latest issues.

Articles in this series:
  • Computer Bits (July 1989)
  • Computer Bits (August 1989)
  • Computer Bits (September 1989)
  • Computer Bits (October 1989)
  • Computer Bits (November 1989)
  • Computer Bits (January 1990)
  • Computer Bits (April 1990)
  • Computer Bits (October 1990)
  • Computer Bits (November 1990)
  • Computer Bits (December 1990)
  • Computer Bits (January 1991)
  • Computer Bits (February 1991)
  • Computer Bits (March 1991)
  • Computer Bits (April 1991)
  • Computer Bits (May 1991)
  • Computer Bits (June 1991)
  • Computer Bits (July 1991)
  • Computer Bits (August 1991)
  • Computer Bits (September 1991)
  • Computer Bits (October 1991)
  • Computer Bits (November 1991)
  • Computer Bits (December 1991)
  • Computer Bits (January 1992)
  • Computer Bits (February 1992)
  • Computer Bits (March 1992)
  • Computer Bits (May 1992)
  • Computer Bits (June 1992)
  • Computer Bits (July 1992)
  • Computer Bits (September 1992)
  • Computer Bits (October 1992)
  • Computer Bits (November 1992)
  • Computer Bits (December 1992)
  • Computer Bits (February 1993)
  • Computer Bits (April 1993)
  • Computer Bits (May 1993)
  • Computer Bits (June 1993)
  • Computer Bits (October 1993)
  • Computer Bits (March 1994)
  • Computer Bits (May 1994)
  • Computer Bits (June 1994)
  • Computer Bits (July 1994)
  • Computer Bits (October 1994)
  • Computer Bits (November 1994)
  • Computer Bits (December 1994)
  • Computer Bits (January 1995)
  • Computer Bits (February 1995)
  • Computer Bits (March 1995)
  • Computer Bits (April 1995)
  • CMOS Memory Settings - What To Do When The Battery Goes Flat (May 1995)
  • Computer Bits (July 1995)
  • Computer Bits (September 1995)
  • Computer Bits: Connecting To The Internet With WIndows 95 (October 1995)
  • Computer Bits (December 1995)
  • Computer Bits (January 1996)
  • Computer Bits (February 1996)
  • Computer Bits (March 1996)
  • Computer Bits (May 1996)
  • Computer Bits (June 1996)
  • Computer Bits (July 1996)
  • Computer Bits (August 1996)
  • Computer Bits (January 1997)
  • Computer Bits (April 1997)
  • Windows 95: The Hardware That's Required (May 1997)
  • Turning Up Your Hard Disc Drive (June 1997)
  • Computer Bits (July 1997)
  • Computer Bits: The Ins & Outs Of Sound Cards (August 1997)
  • Computer Bits (September 1997)
  • Computer Bits (October 1997)
  • Computer Bits (November 1997)
  • Computer Bits (April 1998)
  • Computer Bits (June 1998)
  • Computer Bits (July 1998)
  • Computer Bits (November 1998)
  • Computer Bits (December 1998)
  • Control Your World Using Linux (July 2011)
Articles in this series:
  • The Technology Letters, Pt.2 (January 1989)
  • The Story Of Electrical Energy (July 1990)
  • The Story Of Electrical Energy; Pt.2 (August 1990)
  • The Story Of Electrical Energy; Pt.3 (September 1990)
  • The Story Of Electrical Energy; Pt.4 (October 1990)
  • The Story Of Electrical Energy; Pt.5 (November 1990)
  • The Story Of Electrical Energy; Pt.6 (December 1990)
  • The Story Of Electrical Energy; Pt.7 (January 1991)
  • The Story Of Electrical Energy; Pt.8 (February 1991)
  • The Story Of Electrical Energy; Pt.9 (March 1991)
  • The Story Of Electrical Energy; Pt.10 (May 1991)
  • The Story Of Electrical Energy; Pt.11 (July 1991)
  • The Story Of Electrical Energy; Pt.12 (August 1991)
  • The Story Of Electrical Energy; Pt.13 (September 1991)
  • The Story Of Electrical Energy; Pt.14 (October 1991)
  • The Story Of Electrical Energy; Pt.15 (November 1991)
  • The Story Of Electrical Energy; Pt.16 (December 1991)
  • The Story Of Electrical Energy; Pt.17 (January 1992)
  • The Story Of Electrical Energy; Pt.18 (March 1992)
  • The Story Of Electrical Energy; Pt.19 (August 1992)
  • The Story of Electrical Energy; Pt.20 (September 1992)
  • The Story Of Electrical Energy; Pt.21 (November 1992)
  • The Story Of Electrical Energy; Pt.22 (January 1993)
  • The Story of Electrical Energy (April 1993)
  • The Story Of Electrical Energy; Pt.24 (May 1993)
  • The Story Of Electrical Energy; Pt.24 (June 1993)
Articles in this series:
  • Amateur Radio (November 1987)
  • Amateur Radio (December 1987)
  • Amateur Radio (February 1988)
  • Amateur Radio (March 1988)
  • Amateur Radio (April 1988)
  • Amateur Radio (May 1988)
  • Amateur Radio (June 1988)
  • Amateur Radio (July 1988)
  • Amateur Radio (August 1988)
  • Amateur Radio (September 1988)
  • Amateur Radio (October 1988)
  • Amateur Radio (November 1988)
  • Amateur Radio (December 1988)
  • Amateur Radio (January 1989)
  • Amateur Radio (April 1989)
  • Amateur Radio (May 1989)
  • Amateur Radio (June 1989)
  • Amateur Radio (July 1989)
  • Amateur Radio (August 1989)
  • Amateur Radio (September 1989)
  • Amateur Radio (October 1989)
  • Amateur Radio (November 1989)
  • Amateur Radio (December 1989)
  • Amateur Radio (February 1990)
  • Amateur Radio (March 1990)
  • Amateur Radio (April 1990)
  • Amateur Radio (May 1990)
  • Amateur Radio (June 1990)
  • Amateur Radio (July 1990)
  • The "Tube" vs. The Microchip (August 1990)
  • Amateur Radio (September 1990)
  • Amateur Radio (October 1990)
  • Amateur Radio (November 1990)
  • Amateur Radio (December 1990)
  • Amateur Radio (January 1991)
  • Amateur Radio (February 1991)
  • Amateur Radio (March 1991)
  • Amateur Radio (April 1991)
  • Amateur Radio (May 1991)
  • Amateur Radio (June 1991)
  • Amateur Radio (July 1991)
  • Amateur Radio (August 1991)
  • Amateur Radio (September 1991)
  • Amateur Radio (October 1991)
  • Amateur Radio (November 1991)
  • Amateur Radio (January 1992)
  • Amateur Radio (February 1992)
  • Amateur Radio (March 1992)
  • Amateur Radio (July 1992)
  • Amateur Radio (August 1992)
  • Amateur Radio (September 1992)
  • Amateur Radio (October 1992)
  • Amateur Radio (November 1992)
  • Amateur Radio (January 1993)
  • Amateur Radio (March 1993)
  • Amateur Radio (May 1993)
  • Amateur Radio (June 1993)
  • Amateur Radio (July 1993)
  • Amateur Radio (August 1993)
  • Amateur Radio (September 1993)
  • Amateur Radio (October 1993)
  • Amateur Radio (December 1993)
  • Amateur Radio (February 1994)
  • Amateur Radio (March 1994)
  • Amateur Radio (May 1994)
  • Amateur Radio (June 1994)
  • Amateur Radio (September 1994)
  • Amateur Radio (December 1994)
  • Amateur Radio (January 1995)
  • CB Radio Can Now Transmit Data (March 2001)
  • What's On Offer In "Walkie Talkies" (March 2001)
  • Stressless Wireless (October 2004)
  • “Degen” Synthesised HF Communications Receiver (January 2007)
  • WiNRADiO: Marrying A Radio Receiver To A PC (January 2007)
  • PICAXE-08M 433MHz Data Transceiver (October 2008)
  • Half-Duplex With HopeRF’s HM-TR UHF Transceivers (April 2009)
  • Dorji 433MHz Wireless Data Modules (January 2012)
Articles in this series:
  • Remote Control (October 1989)
  • Remote Control (November 1989)
  • Remote Control (December 1989)
  • Remote Control (January 1990)
  • Remote Control (February 1990)
  • Remote Control (March 1990)
  • Remote Control (April 1990)
  • Remote Control (May 1990)
  • Remote Control (June 1990)
  • Remote Control (August 1990)
  • Remote Control (September 1990)
  • Remote Control (October 1990)
  • Remote Control (November 1990)
  • Remote Control (December 1990)
  • Remote Control (April 1991)
  • Remote Control (July 1991)
  • Remote Control (August 1991)
  • Remote Control (October 1991)
  • Remote Control (April 1992)
  • Remote Control (April 1993)
  • Remote Control (November 1993)
  • Remote Control (December 1993)
  • Remote Control (January 1994)
  • Remote Control (June 1994)
  • Remote Control (January 1995)
  • Remote Control (April 1995)
  • Remote Control (May 1995)
  • Remote Control (July 1995)
  • Remote Control (November 1995)
  • Remote Control (December 1995)
MARKET CENTRE Cash in your surplus gear. Advertise it here in Silicon Chip. r-------------------------, FOR SALE CLASSIFIED ADVERTISING RATES Advertising rates for this page: Classified ads - $7.00 for up to 15 words plus 40 cents for each additional word. Display ads (casual rate) - $20 per column centimetre (Max. 10cm). Closing date: five weeks prior to month of sale. If you use a PO Box number you must include your permanent address and phone number for our files: We cannot accept ads submitted without this information. To run your classified ad, print clearly on the lines below or on a separate sheet of paper & send the form together with your cheque or credit card details to : Silicon Chip Classifieds, PO Box 139, Collaroy Beach, NSW 2097. Or fax the details to (02) 979 6503. WEATHER FAX programs for IBM XT/ ATs *** "RADFAX2" is a high resolution, shortwave weather fax, Morse & RTTY receiving program. Needs CGA, SSB HF radio & Radfax decoder. Also "RF2HERC", "RF2EGA" & "RF2VGA", same as RADFAX2 but suitable for Hercules, EGA & VGA cards respectively. $35. *** "SATFAX" is a NOAA, Meteor & GMS weather satellite picture receiving program. Uses EGA & VGA modes, needs EGA or VGA colour monitor & card, plus "WEATHER FAX" PC card. $45. *** All programs are on 5.25-inch or 3.5-inch discs (state which) & include documentation. Add $3 postage. ONLY from M. Delahunty, 42 Villiers St, New Farm, 4005 Old. Phone (07) 358 2785. MODEL TRAIN CONTROLLER: see SILICON CHIP November 1990, $19.95 plus $2.50 p&p. Plugpack, 12VAC, 1.7A, suitable for above (use rectifier), $29.95 plus $4.00 p&p. Kits built & repaired. Prototype production board supplier to the hobbyist & supplier of SILICON CHIP project PCBs. Electronic Toy Services, PO Box 491, Noarlunga Centre, SA 5168. Phone (08) 382 8919. LASER SALES & service. All types from 30mW to 20 watts, also scanners IIT MATHS Enclosed is my cheque/money order for $_ __ _ or please debit my Cl Bankcard Card No. Cl Visa Card Cl Master Card ~ .______,_____,I '---I.,____.__.__I ~I'----"--.__I ~I '----"--L_____j Signature_ _ _ _ _ _ _ _ _ _ _ Card expiry date._ _ _,/_ __ Name _ _ _ __ _ _ _ __ _ _ __ _ _ _ _ _ _ __ _ COPROCESSORS 2C-08 2C-10 2C-12 2C-20 2C87- 8MHZ 2C87-10MHZ 2C87-12MHZ 2C87-20MHZ 3C-16 3C87-16MHZ $640 3C-20 3C87-20MHZ $680 3C-25 3C87-25MHZ $840 3C-33 3C87-33MHZ $990 These pices include Sales Tax. Stocks are limited at this price, so order early. Street _ _ _ _ __ __ _ _ _ _ _ __ _ _ __ _ _ __ Suburb/town _ _ _ _ _ __ _ ____ Postcode_ __ _ __ L-------------------------J 118 SILICON CHIP PHONE (02)957 67 FAX (02)954 5550 ► ..I (/) D. D. (l) '- -§ ~ c.) Ill - a..o ~ ~ti Cll -~ (1)111 0111 a,.u, ~ -6 W ~ a-~ o: C ~(/) gi ~ 0: ~ ti-c ~ ~ C1l -~ >,..: co "ffi -0 ~o ~ D. ~~(l)Cl)N«l u, jjj?J: -C"ll ·.=·s; t: (/) (l) (l) ~'-OlQJ>...J (/) ..92 e _.cCll ~~ (l) -~ L ©Cl)Q)~~ a>o •e.c ~ c( -~ ~ 0 ~ ~ ;r: u, r 0(1)<((1)0 ►~ IC") E» .c - ~- ·--~~~ a 5i o;.: ~.,... o. (/) m .E ~ Ia, E .!::: ._ m (,) .,... 8 ~ C"ll c.:!= § <i>OlO.Cl)Q+- CD'--o Ol(/)..,....3:o 0 0 Q) >, ....!::: Q) 0 :;: Ol ai (/) «i o.- Cl> 0 .C'cECl)O.o_mc., >.c Lt) en (,) )( ~~o.o._c - co Z LL lli Ill :i -~ 3: t C - ~ o.-oOo, .c · - ~ ~, (l) Ql ·:::; C E §: a.. §: ·u5 oco-"''-'-~c c.) 0 :::, :::, (l) :::, «i ~ ~ cr o !: CHRISTMAS CLEARENCE SALE N C C ...a ~ ~ .J -~ "6> ::, :i C'• ~ w <i: ..2 - en ... w~ ..I Lt) Ill -a 1-~ 0 a; C 0. r:;- ~ ◄ g . a. .c SURPLUS STOCK AT REDUCED PRICES Only Items listed on Special - while stocks last BC548/558 BC547/557 BC549/559 BC107/108 BC327/337 8D139/140 TIP31 C/32C 2N2222 2N3055 MJ2955 $0.09 $0.09 $0.09 $0 .30 $0.20 $0.35 $0.60 $0.33 $1 .30 $1.40 t - - - - -~ - JIFFY Box with lid UB1 50x90x150mm UB3 41x68x130mm UB5 28x54x83mm Money Order or Cheque M. Radvanyi, PO Box 49, Kingswood, NSW, 2749 from basic to animated 3-D images. Special: air-cooled argon 120mW laserhead (8 lines), blue to green. Includes small lightweight switchmode PSU, interlock keyswitch, remote option, $9000.00. PO Box 215, Geelong, Vic 3214. Telephone (052) 48 3503. MS-DOS NOTEBOOK-SIZE computers. Have you been looking at the Atari Portfolio, POQET or PSION computers? Perhaps the "NEW FOR 91" NOTEBOOK TANDY 1100-FD is the one for you. With a built-in 3.5-inch floppy & 640Kb of RAM, this unit is hard to beat. Don't buy one until you have a look at my free brochure. I can save you $100-$260 on this unit. Don McKenzie, 29 Ellesmere Crescent, Tullamarine 3043. Phone (03) 338 6286. Potentiometer: $ 8.00 555 Timer $0.29 $ 8.00 741 Op Amp $0.35 $ 8.00 CMOS 4000 $0.45 $ 29.00 4001 $0.25 $ 19.00 4011 $0.25 $ 30.00 4017 $0.40 $ 55.00 Reg uA7805 $0.45 $ 29.00 Zener Diodes $120.00 3 to 33 volt $130.00 400mW $0.10 ~ ----, 1 Watt $0.15 SCR C103Y $0.30 $ 2.95 C103B $0.50 $ 2.40 25A C37D $2.00 $ 1.95 Diac ST2 $0.20 24mm Linear 1/4" 50eea 500W, 1K, 5k, 25K, SOK, 100K, 250K, 1M, 2M, TRIMPOTS 10mm vert 12e 250W, 1K,2K,5K, 10K,25K, 250K GREENCAPS 100V: .001 se, .0039 9e, .0047 1oe .033 , 1e .. 22 1se. .33 22e, .47 2se, CERAMIC Caps: 50volt 2.2, 100, 2200, 3300, 4700pF all se. .01, .033, .047uF all 7e 1000/25V 35~ 3.5mm panel sockets 20~ Banana plug/socket 25~ Ferrite rod 106x10mm 40~ Ferrite flat 60x12x6mm 25~ MIXED BAGS - Capacitors plus resistors: $2.00 per 100, $8.00 per 500, $15.00 per 1000. MYSTERY BAGS • broad range all usable (15.00 individual value) for $5.00 per 100. DIGGERMAN ELECTRONICS PO BOX 33 CORAMBA, NSW, 2450 Postage $1.00 minimum or 10% of order value KIT REPAIRS Kits repaired from all magazines. PCs and peripherals also repaired Ring anytime 9am - 9pm EEM ELECTRONICS 1O Bouverie Place Epping Vic. 3076 (03) 401 1393 TOROID POWER TRANSFORMERS From quality UK manufacturers. Available from stock at discount prices, 15VA to 625VA. Send SSAE for data & prices to: Transformer Discounters, PO Box 542, Wahroonga 2076. ACTIVE SHORTWAVE ANTENNA SILICON CHIP, JAN 1990. Complete kit Tested $t19.00, Case $10.00. $59.00, Built and LOOP ANTENNA Improve signal strength & quality wi1h this portable antenna. Kit $44.00, Buitt and Tested $69.00 COMPACT INDOOR FM ANTENNAS Two models to choose from. Terk FM2000 a passive loop FM antenna for $69.95 or the Terk Pl2 powered FM antenna with wideband low noise filter for $199.00. We can a/eo provide ....,,,bly facllltln for 111n11II prodUct/on runa at com,,.,ltlve prk:H VALVES: 6V6G, 3S4, 2X2/879, DF64, IC7G, VR118, 3C45, 12E1, G50/1G, GC10/48, 7583, 2T4C, 1421A.AII Nos. Phone: Hycal Instruments (02) 633 5897 MEDTRON PROGRESSIVE Treatment Unit, with manual; Mullard valve tester with spare parts; BAC221-AC Frequency Set with AC supply in mint con- Popular ICs ELECTROs 16V Upright:220uF 15~, 470uF 20~1000uF 30~. GENERATE YOUR OWN DIGITAL WAVEFORMS As described in SILICON CHIP in March, May, June & July 1990. ALSO suits the design described in Electronics Australia Software and PC Board $39.95 inc. P&P Software only $32.50 inc. P&P 100 TRANSISTORS EACH JILOA (TECHNIKIT DIVISION) PO Box 73, Glenhuntly, VIC 3163. Telephone: (03) 571 6303 dition; offers please. Phone Hycal Instruments (02) 633 5897. CAPACITORS: 2,000µF 25volt, chassis mounting $1.00 each; 0.47 Farad & 0.1 Farad only $5.00 each; slider pots 50k0 linear 45mm travel $1.q0; MC14514BPC $2.00; LM7812 & LM7912 $0.70 each; LM324 $0.75; 9volt battery connectors $0.20; battery DECEMBER 1990 119 MEMORY EXPANSION SIMM & SIP 9 X 256 9x 1MB 8 x 1MB(MAC) 9x4MB -120ns -100ns - 80ns - 70ns - 60ns -100ns - 80ns - ?Ons - sons - 70ns - 80ns N/A 23.00 23.80 24.70 30.00 79.00 81.50 89.50 76.50 82.00 528.00 -100ns - sons - 80ns - 80ns - 80ns 2.10 2.40 2.50 7.65 7.65 Prices At Sept. 13, 1990 CO-PROCESSORS INTEL 8087-2 80287-10 80C287-12 387SX-16 387DX-16 387SX-20 387DX-20 387DX-25 387DX-33 175.00 308.00 390.00 435.00 478.00 490.00 538.00 680.00 835.00 CYRIX 387SX-16 387DX-20 387DX-33 400.00 490.00 750.00 515.00 340.00 340.00 340.00 340.00 570.00 340.00 340.00 2MB 2MB 2MB 2MB 2MB 3MB 2MB 2MB COMPAQ 386-20, 386-25, 386-20E, 386-S, 386-33 680.00 4MB MODULES 4MB BOArds 798.00 IBM PS/2 DRAM/DIP 4164 41256 41464 4 X 256 1MB Advertising Index TOSHIBA LAPTOP T1000SE T1600 T3100E T3100SX T3200SX T3200 T5100 T5200 PELHAM WEITEK 3167-20 3167-33 4167-25 4167-33 820.00 1010.00 1500.00 1780.00 30/286,50 70E61, 121 70A21 2MB 2MB 2MB 250.00 280.00 280.00 Sales Tax 20%. Overnight Delivery. Credit Cards Welcome 1st Floor, 100 Yarrara Road, Pennant Hills, NSW 2120. Tel (02) 980 6988 Fax (02) 980 6991 holder 2 x AA $0.28; 1N5404 $0.30; 1N5819RL $1.00; 1N4742 (12-volt zener) $0.24; 1N752 (5.6-volt zener) $0.18. Minimum order $5.00. All stock is new. Phone Hycal Instruments (02) 633 5897. 1GHz DIGITAL FREQUENCY Meter, AEM July 1986, fully built, calibrated with 12-month warranty. $300.00. Hycal Instruments (02) 633 5897. UHF GaAsFET Preamplifier, EA May 1986. Fully built and tested with 12month warranty. $125.00. Hycal Instruments (02) 633 5897. ANTIQUE RADIO restorations. Your one-stop electronic repair shop. Specialising in restoring vintage radios including chassis rewiring, quality new parts, valves, valve sockets, speakers, transformers, cabinet restoration. Quality secondhand radio dials & parts for most brands & models. About 400 radios in stock for restoration & parts. Every restored wireless is covered by a 2-year warranty on parts & service. French polishing of timber cabinets available. Vintage car radios in valve & transistor types available for restoration. Repairs done on tape decks, amplifiers, TVs & videos. Open Sat. 1Oam-Spm; Sun. 12.30-Spm. 109 Cann St, Bass Hill, 2197. Phone (02) 645 3173 BH or (02) 7261613 AH. r-------------------------, : I I I SILICON CHIP BINDERS To: Silicon Chip Publications, PO Box 139, Collaroy Beach, NSW 2097, Australia. ~ cfib Yes! Please send me _ _ _ SILICON CHIP binder(s) at $A11.95 plus $A3 p&p each (NZ $A6 p&p). Enclosed is my cheque/money order for $_____ or please debit my 0 Bankcard O Visa Card O Master Card Card No. Signature_ _ _ _ _ _ _ _ _ _ __ Card expiry date_ _~/_ __ Name _ _ __ _ _ _ _ _ __ _ _ _ _ _ _ __ _ _ __ __ Street _ _ _ _ __ _ _ _ _ _ _ __ _ __ _ __ __ _ __ Suburb/town _ _ _ _ _ _ _ _ _ _ _ __ Postcode_ _ _ _ __ _ ~ - - - - - - - - - - - - - - - - - - - - - - ---J 120 SILICON CHIP Adroit Electronics .................... 119 Altronics .. ..... ..... .................. 33-37 Arista................ ............ 45,92, 101 Back Issues ..................... .. ... 96,97 Bridge Electronics .................... 51 Board Solutions.... ........ 78,79, 103 Cad Connection .. .............. ... ... 118 David Reid Electronics ........ IFC,1 94,95 Dick Smith Electronics .. ........ 8-13 Diggerman Electronics .. .......... 119 EEM Electronics ...................... 119 Electronic Solutions ........... . 21,88 Electronics World .. .. .. ........... . 106 Elmeasco ............................ 85,90 Geoff Wood Electronics .. .. .. .. .. 53 Harbuch Electronics .. ....... .. ... 107 Hycal Instruments .................... 119 Jaycar Electronics ................ 57-64 Jiloa ....... .. ....... .. ............ ... .. .... .. . 119 J.V. Tuners .............................. 51 Oatley Electronics ......... ........... 90 Pacific Microelectronics ..... .. ... 49 PC Marketplace .... ................ IBC Pelham .................................. 120 Philips T&M ... .... ... .......... 87,89,91 RCS Radio ... ... ....... .. .. .. .. .. ..... .. 52 Resurrection Radio .. .. .. .. .. .. .. .. .. 69 Rod Irving Electronics ... ....... 30,31 46,47, 108,109 Sheridan Electronics ................ 113 Silicon Chip Binders .............. OBC Subscriptions .. ... .. .. .... ... ........ .. 65 Sound Australia ...... .. .. .. ............ 45 Transformer Discounters ........ 119 PC Boards Printed circuit boards for SILICON CHIP projects are made by: • Electronic Toy Services, 2/111 Glynville Drive, Hackham West, SA 5163. Phone (08) 382 8919. • Jemal Products, 5 Forge St, Welshpool, WA 6106. Phone (09) 350 5555. • Marday Services, PO Box 19-189, Avondale, Auckland, NZ. Phone 88 5730. • RCS Radio Pty Ltd, 651 Forest Rd, Bexley, NSW 2207. Phone (02) 587 3491.