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<ul><li><p>THE</p><p>TARBELL</p><p>CASSETTE</p><p>INTERFACE</p><p>TARBELL ELECTRON ICS20620 S. Leapwood Ave., Suite P</p><p>Carson, California 90746(213) 538-4251</p></li><li><p>TABLE OF CONTENTS</p><p>PAGE</p><p>1. Specifications2. Interface History and Sales Pitch3. Selecting a Cassette Unit for Digital RAcording4. The Kansas City (Byte!Lancaster/CUTS) Format</p><p>5. Parts List6. Assembly Instructions7. Assembly Drawings8. Modifications9. Soldering, Cleaning, and Installation Notes10. Initial Adjustment Instructions</p><p>11. Operating Instructions12. Bootstrap and Sync Code Generator Programs13. Output Routine With Checksum14. Input Routine With Checksum15. How to Save and Load Data From a BASIC Program16. Controlling the Start-Stop Function</p><p>17. Theory of Operation - Output Section18. Theory of Operation - Input Section19. Schematic - Output Section20. Schematic - Input Section21. Timing Diagram22. Pin Function List</p><p>23. If You Have Problems24. Ideas For Using the Cassette Interface25. Modifications on Cassette BASIC CSAVE and CLOAD26. Processor Technology Software Package #1 Modified27. Writing Programs For the Cassette Interface28. Interrupt Control29. PHI-DECK Adapter Information</p><p>30. 74f.LOO, 7403, 74L11, 74()4., 74L04, 7406, 7425, 7408, 74L3031. 74L73 , 7473, 74L7432. 74L75 , 74L8633. 7496, DM813134. 74L164 , NE55535. 8T20</p><p>36. Customer Evaluation and Registration</p><p>January 14, 1977</p></li><li><p>TMd:H.lL ELECl H~)I\ilC3'-"""""""0 c L ~ .. ",~ dr'" (:, .. ;'.,.. f.)LU\..)L d. COj.JhdO -\,8., v . ,." I</p><p>Carson, Cdi[f.&gt;rnia 90746(213) 5384251</p><p>THE TARBELL CASSETTE INTERFACE (FOR ALTAIR 8800 USERS)</p><p>SPEED: UP TO 540 BYTES PER SECOND (2200 BITS PER INCH).187 BYTES PER SECOND FOR TARBELL STANDARD 800 BITS/INCH.30 BYTES PER SECOND FOR "BYTE/LANCASTER" STANDARD.</p><p>ENCODING METHOD: PHASE-ENCODED (EXCLUSIVE-OR OF CLOCK AND DATA).SELF-CLOCKING (CLOCK VARIES ALONG VITH TAPt SPEED).USED ON MY OWN SYSTEM FOR THE LAST 4 YEARS.CAN BE USED TO GENERATE "BYTE/LANCASTER" TAPIS.</p><p>CASSETTE. WILL WORK WITH MOST AUDIO CASSETTE UNITS. MAY BE ADAPTEDTO AUTOMATIC DIGITAL CASSETTE UNITS. WILL ALSO WORKWITH REGULAR REEL-REEL TAPE RECORDERS. I HAVE BEE~ USINGA REALISTIC (RADIO SHACK) CTR-19 AND A u.c. PENNY 6536'($39.95). TAPE SHOULD BE OF LOW-NOISE TYPE.</p><p>8192 BYTE LOAD TIME. 15 SEC' 540 BYTES PER SECOND.43 SEC' 187 BYTES PER SECOND.4 MINUTES' 30 BYTES PER SECOND.</p><p>DEVICE-CODE EASILY SELECTED WITH ON-BOARD DIP-SVITCH.</p><p>STATUS. 4 EXTRA STATUS LINES AVAILABLE FOR INPUT.</p><p>CONTROL: 4 EXTRA CONTROL LINES AVAILABLE FOR OUTPUT" WHICH MAYBE USED TO DRIVE RELAYS FOR EXTRA CASSETTE UN11S;2 SPARE IC SLOTS TO LET YOU DO YOUR OVN THING.</p><p>COMPATIBILITY: PLUGS DIRECTLY INTO ALTAIR 8800 OR IMSAI 8080.HAS SERIAL-PARALLEL AND PARALLEL-SERIAL CONVERSIONON BOARD. PATCHES PROVIDED FOR POPULAR SOFT_ARE.</p><p>SOFTWARE: COMES WITH COMPLETE SET OF INPUT/OUTPUT SUBROUTI~ES"BOOTSTRAP" AND "BYTE STANDARD" (LANCASTER) SOFTWARE.</p><p>COST: S120 rOR COMPLETE KIT" S175 ASSEMBLED AND CHECKED-OUT.</p><p>MANUALsASSEMBLY INSTRUCTIONS AND DRAWING" PARTS AND PIN FUNCTION LISTSSOLDERING, CLEANING" AND INSTALLATION NOTESI OPERATING INSTRUCTIONSINITIAL AD~STMENT PROCEDURES, INPUT/OUTPUT ROUTINES WITH CHECkSUMBOOTSTRAP PROGRAM AND TEST-STREAM GE~ERATOR PROGRAM .</p><p>PARTS IALL RESISTORS" CAPACITORS, AND INTEGRATED CIRCUITSCASSETTE CABLE, RIBBON CABLE" AND DIP CONNECTORLOW-NOISE CASSETTE WITH TEST STREAMDOUBLE-SIDED BOARD WITH PLATED-THRU HOLES AND GOLD EDGE CONHEeTOR</p><p>-. ~.~</p><p>WARRANTY I IF NOT COMPLETELY SATISFIED, RETURN BOARD FOR REFUNDOR FREE REPAIR WITHIN 90 DAYS AFTER PURCHASE.</p><p>FIRST DELIVERIES WERE MADE IN SEPTEMBER, 1975. DELIVERY IS1 TO 3 WI&amp;~S AFTER RECEIVING ORDER. THE 2S-PAGE MANuAL IS AVAILABLEAT $4. 'CAtIFORNIA RESIDENTS PLEASE ADD 61 SALES TAX. MAJ</p></li><li><p>HISTORY AND SALES PITCH</p><p>I HAVE BEEN USING AN INEXPENSIVE AUDIO CASSETTE RECORDER INMY HOME-DESIGNED COMPUTER SYSTEM SINCE 1972. 1 HAVE OVER600 FILES ON CASSETTESI MOSTLY ABOUT 4 ~YTES EACH.MY ESTIMATE IS THAT THE ERROR RATE IS LESS THAN 1 ERROR IN110001000 BITS. I SAY THIS BECAUSE I CAN USUALLY RECORD 304 KBYTE FILES ON ONE SIDE OF A C-60 CASSETTE WITHOUT ANY ERRORS.THIS INTERFACE GAVE ME VERY GOOD SERVICE WHILEI WAS WRITING THE DISX OPERATING SYSTEM FOR MY 500 XBYTE DISK.SINCE I STARTED USING MY DISX SYSTEM A FEW YEARS AGOI THECASSETTE HAS SERVED AS BACKUP STORAGE - A RELIABLE PLACETO STORE DATA AND PROGRAMS AFTER THEY ARE DEBUGGED.</p><p>THE ENCODING METHOD I USE IS VERY SIMPLEI AND HAS BEEN INUSE IN INDUSTRY FOR QUITE SOME TIME. PICTURE A SHIFT REGISTERWHICH IS LOADED WITH THE DATA TO BE RECORDED. THE REGISTERIS THEN CLOCKED WITH A SQUARE WAVE. THE OUTPUT OF THE SHIFTREGISTER IS EXCLUSIVE-ORED WITH THE CLOCXI PRODUCING THEBI-PHASE DATA. THIS DATA GOES DIRECTLY TO THE CASSETTERECORDER'S INPUT. THE MOST DIFFICULT PART OF THE PROCESS 15RECOVERING THE DATA. MANY LONG HOURS WERE SPENT STUDYING THISPROBLEM AND TRYING DIFFERENT METHODS. IN THE ORIGINAL INTERFACETHIS WAS ACCOMPLISHED WITH A 760 HIGH-SPEED COMPARATORI A 14121NON-RETRIGGERABLE ONE-SHOTI AND A DOUBLE-GLITCH GENERATOR HADEWITH AN EXCLUSIVE-OR GATE. SINCE THENI THE 8T20 HAS BEEN DEVELOPEDJWHICH COMBINES THESE THREE FUNCTIONS ON A SINGLE CHIPI AND IS THEUNIT USED IN THE ALTAIR INTERFACE.</p><p>THE PRESENT DESIGN IS EVEN MORE RELIABLE THAN THE PREVIOUS ONEIAND IS CAPABLE OF RECORDING AND RECOVERING ERROR-FREE DATA ATA RATE OF 540 BYTES PER SECOND ON A STANDARD AUDIO CASSETTERECORDER. (YESI THAT IS OVER 2200 BITS PER INCHI) I AH STILLIHOWEVERI ENCOURAGING USERS TO EXCHANGE DATA RECORDED AT 181BYTES PER SECOND C1500 BITS PER SECONDI 800 BITS PER INCH).THE MAIN ADVANTAGE OF THIS METHOD OVER OTHERS IS IT'S ABILITY TOWITHSTAND A LARGE AMOUNT OF WOW AND FLUTTERI WHICH MAY BE INTRODUCEBY CHEAP RECORDERSI AND STILL RECOVER THE DATA RELIABLY. THISFEATURE STEMS FROM THE SELF-CLOCKING NATURE OF THE RECORDED SIGNAL:THE RECOVERED CLOCK VARIES RIGHT ALONG WITH THE DATAl SO THAT THtSPEED VARIATIONS ARE ESSENTIALLY IGNORED. THE MAIN DISADVANTAGEOF THIS METHOD IS THAT IT REQUIRES GOOD LOW-NOISE TAPEI AND ADECENT FREQUENCY RESPONSE ON THE CASSETTE UNIT. THE CASSETTE UNITI'VE BEEN USING LATELY Cu.C. PENNY 16536) HAS A FREQUENCY RESPONS80-81000 HZ. THE MOST IMPORTANT PART 15 THE HIGH END. THESEREQUIREMENTS ARE DUE TO THE HIGH SPEED OF THE INTERFACE 1 AND WOULDBE THE SAME FOR ANY HIGH SPEED DEVICE.</p><p>THE SPEED MAY NOT SEEM VERY IMPORTANT TO YOU NOW. BUT A GOODPORT ION OF YOUR TIME IS GO ING TO BE SPENT SAV ING AND LOAD INGDATAl PROGRAMSI AND OTHER TEXT. THERE IS A WORLD OF DIFFERENCEBETWEEN LOADING BASIC AT SAYI 30 BYTES/SEC C4 MINUTES), ANDAT 187 BYTES/SEC C40 SEC). IT DOESN'T SEEM LIKE MUeHl BUTWHEN YOU HAVE TO DO IT OVERI AND OVER, AND OVER IT GETSTO BE A BIT MUCH. ESPECIALLY WHEN YOU'RE DEVELOPING YOUR OWNPROGRAMSI AND THEY TEND TO RUN AMUCK AND WIPE OUT CORE.THINK ABOUT ITI THEN BUY THE TARBELL CASSETTE INTERFACE.THE ONLY METHOD PROVEN WITH TIME. ASX YOUR FRIEND WHO HAS ONE.</p><p>2</p></li><li><p>SELECTING A CASSETTE UNIT FOR DIGITAL RECORDING</p><p>FIRST OF ALL~ THE MOST EXPENSIVE CASSETTE RECORDERSARE NOT NECESSARILY THE BEST FOR RECORDING DIGITAL DATA.THERE ARE SEVERAL FACTORS THAT COMBINE TO HAKE A GOODUNIT FOR THE HOBBYIST'</p><p>1. IT SHOULD HAVE A GOOD HIGH-FREQUENCY RESPONSE,PREFERABLY UP TO AT LEAST B,OOO HZ.</p><p>2. IT SHOULD HAYE A TONE CONTROL, SO THAT THE INHERENTFREQUENCY RESPONSE HAY BE REALIZED. '</p><p>3. ALTHOUGH AUTOMAT IC VOLUME CONTROL IS MORE CONVENIENTFROM AN OPERATIONAL POINT OF VIEW, IT ALSO REQUIRESA FEW SECONDS OF SETTLING TIME BEFORE STARTING to RECORD.</p><p>4. IF IT DOES NOT HAVE AUTOMATIC VOLUME CONTROL, IT IS GOOD TOHAVE A RECORDING LEYEL METER. THIS ALLOWS EASlER ADJUSTMENTFOR THE CORRECT RECORDING LEYEL.</p><p>5. IT IS YERY IMPORTANT TO HAYE A DIGITAL COUNTER. THISMAKES IT POSSIBLE TO QUICKLY LOCATE THE DESIRED PROGRAMAMONG SEVERAL.</p><p>6. IT SHOULD BE CAPABLE OF RUNNING DIRECTLY ON THE AC LINE.BATTERIES TEND TO MAKE THE MOTOR GET SLOWER AS THEY YEAR.</p><p>7. IT 15 HANDY TO HAVE AN AUXILLIARY INPUT, SO THAT A FAIRLYHIGH LEVEL MAY BI FED TO TaE RECORDER, AND NOlSE kEPt-TOA MINIMUM.</p><p>8. A REMOTE INPUT ~CK IS VALUABLE TO CONTROL START-STOPDURING ASSEMBLER AND COMPILER OPERATIONS.</p><p>9. JACKS FOR MIC~ AUX, REMOTE, AND EARPHONE ARE USUALLY INGLVE&gt;ID,BUT YOU SHOULD CHECK TO MAKE SURE THEy ARE THERE~ ANYfAY.. .</p><p>10. LOW WOW AND FLUTTER CHARACTERISTICS ARE IMPORTANT, BUT AREHUCH MORE IMPORTANT WHEN USING AN ASYNCRONOUS INTERfACE,WHICH IS NOT SELF-CLOCKING.</p><p>11. IF IT IS DESIRED TO DO AUTOMATIC REWIND, FAST-FORWARD,AND RECORD/PLAYBACK SWITCHING UNDER PROGRAM CONTROL, YOUMUST PURCHASE A RECORDER THAT HAS THESE FACILITIES. A_OTHERFEATURE TO LOOK FOR ON THIS TYPE OF UNIT IS A-WAY to ~EP''TRACK OF WHERE YOU ARE ON THE CASSETTE TAPE.</p><p>12. PEOPLE HAVE EXPERIENCED PROBLEMS WITH PANASONIC RECORDERS.I AM PRESENTLY RECOMMENDING THE J.C. PENNEY MODEL 6536 - -AT $39.95 AS THE BEST BUY 1 KNOW,' AND SEVERAL PEOPLE AREUSING THEM WITH MY INTERFACE WITH GOOD RESULTS. OTHER .,BRANDS THAT I KNOW HAYE BEEN SUCCESSFUL ARE SONY ANO"REALlSTIC.</p><p>, ..- ...</p><p>OF COURSE, NONE OF THE ABOVE ITEMS IS ABSOLUTELY NECESSARY FORRECORDING DIGITAL DATA ON AN AUDIO CASSETTE. BUT THE MORE OFTHESE REQUIREMENTS THAT ARE FILLED, THE MORE CAPABLE YOUR-UNIT WILL BE, AND THE EASIER IT WILL 81 TO USE.</p><p>3</p></li><li><p>USING THE TARBIJ..L CAGSETTE INTE..TU'ACE ]'OR 'rRE KANSAS CITY ]'OR11AT</p><p>Some time ago, there was a meeting of various cassette interfacemanl.1faet;urern to deter.nine a. ct1"ul</p></li><li><p>CASSETTE INTERFACE P;\I1T S LIST</p><p>INTEGHATED CIHCUITSREF NOS DESCRIPTION QTY PT NO +S GND -5</p><p>1 QUAD 2-INPUT AND 1 7408 1/~ 72 DUAL .J-}( FLIP-FLOP 1 71J73 4 1 13 8-BIT SHIFT nEG ISTER 1 7'~LI64 14 74,,23 DUAL TYPE-D FL IP-FLOP 2 74L7/~ 14 76 5 "VOLT REGULATOR 1 U13091: INVEHTEH 1 7 /104 1/1 '/21 .. 27 s-n IT SHIFT HEGISTER 2 7/.. 9C) 5 1222 *T II'IER 1 NE555 8 126 QUAD 2- INPUT NAND 1 7/1LOO 14 728 . DUAL 4- INPUT Non 1 7/j25 14 730 QUAD EXC LUS IV1:&gt;-OR 1 74L86 14 732 6-BIT COl~P{l.FMTORS 1 01'18131 16 B34 QUAD LATCH 1 7L!L75 5 1235 HEX INVERTER BUFF'ER O/C 1 7406 14 7</p><p>Cl"C5"ClO-CI5 1 MFD CAPAC ITORC6 .02 1'1I"D CAPACITORC7 .033 011 $039 lWD CAP,;.C ITORC8 *.01 NrD CAP/-\C ITonC9 28 OR 25 1"11"1) C/,;PAC ITORC16 2200 PI" CAPACITORC17 .0 I l'JFD CI-iPAC ITon</p><p>RIR2R3R4R5R6R7R8R9RIO-RI7</p><p>CRICR2CR3</p><p>51</p><p>"1PIPCICSI</p><p>2.!! HOHN RESISTOR (RED"Yl:;LLO\oJ"H)::O)4.7 KOHN RESISTOR (YELLOW"VIOLETJRED)I. fi KOIIM RES ISTOR (BROWN .. GHEEN .. RED)330 OHM RESISTOR (ORANGE"ORANGE"BROWN)220,OHM RESISTOR lW (RED"RED"BROWN)</p><p>*27 KOHM RESISTOR (RED"VIOLET .. ORANGE)*APPROX 10 !-;QHM RES ISTOR CBRO\lTN,BLA.CK.. ORANGE)</p><p>50 EOHN POTENT IONETER100 OHM RES ISTOR CBHOWN"Bl.J'I.G K"HROWN)1 KaHN RES lSTOR (BRDWN"Bl.ACh.. RED)</p><p>IN914 SIGNAL DIODEIN750 4.7 VOLT ZENEn DIODEl.IGHT-EMITTING DIODE</p><p>DIP-SWITCHDIP-SOCKETDIP-PLUG2 CASSETTE COAX CABLESFLAT RIBBON CABl.EPRINTED CIRCUIT BOARDSCOTCH LOW-NOISE CASSETTETO-3 I NSUl...AT ING WAFER.2 SETS OF 4-40 NUTS" SCREWS" AND WASHERS</p><p>* THE ITEMS MARXED WITH AN ASTERISK ARE MATCHED AND BAGGED SEPARATELY.74LS MAY BE SUBSTITUTED FOR 741. SERIES IC'S IN MOST CASES.</p><p>If</p></li><li><p>78</p><p>wC-Q,~</p><p>IoUQ-I</p><p>oC,v'l</p></li><li><p>a iQWI QUIMq'lIs- ..uCaaL_a.,. a D~</p><p>"- ... \,.~.clz ',. !- It I u.I. I .</p><p>~too Ico! QII.</p><p>C1M ,- ! --'I ;. I</p><p>'"Dr: - olDi1M D a~ ~ a"lDIj I-l1li._0 Z-'I&gt;- Z u.I... zm ...'It 0:Ii 1M- A-IAI ..:</p><p>~en :z:Co!) ,W :..,;' 0en hC - U-1MD.</p><p>D.~</p><p>Z</p><p>-ZD.</p><p>'"C:z:</p><p>'"u-00</p><p>1M...0Z</p><p>7..</p></li><li><p>ASSEMBLY INSTRUCT IONS</p><p>/1. TAm: OUT ALL THE PARTS AND CHECK THEN AGAINST THE PARTS 1.1ST.IF THERE ARE ANY PAnTS ~I~SING, Dnop us A NOTE, AND WE WILL'SEND THEM TO you. NOTE Tl!.~T THE NE555" 10]( (APPROX.) RESISTOR ..27K RESISTOR, AND .01 MFD CAPACITOR WHICH ARE PACKAGED IN"THESEPERATE BAG fI!\E i-m.TeBED FOR 1500 HZ AND (.nE: ~'lAHKED U IT1IASTERI$hS ON THE: PAtlTS LIST. OTHER COllI"ONI-:NTS USED FOR TI-lESEWILL CAUSE THE OUTPUT TO RUN AT A DIfFERENT FREQUENCY. "</p><p>2. USING THE AS5El'!;~LY DRI\HING ON PAGE 7 .. INSERT TIlE DISC'~ETf,cor:PONl::NTS WP,G '..1ITH CIiPl\C 110ns, rn;:s ISion~~ .. LED". DljJ</p></li><li><p>MODIFICATIONS ON THE TARBELL CASSETTE INTERFACE AS OF SEPT I~ 1976.</p><p>INCLUDED ON REVISION B:</p><p>I. RESISTOR RI HAS BEEN CHANGED TO A 2.4 KOHM RESISTOR.2. ON THE OUTPUT VOLTAGE DIVIDER~ RIO IS RECOMMENDED TO BE</p><p>I KOHM FOR AUXILLIARY CASSETTE INPUTS~ INSTEAD OF 10 KOHM.</p><p>INCLUDED ON REVISION C:</p><p>3. A.I MFD CAPACITOR HAS BEEN ADDED IN PARALLEL WITH Rl1.THIS IMPROVES RELIABILITY WITH SOME TYPES OF RECORDERS.</p><p>-4. A I KOHM RESISTOR HAS BEEN ADDED BETWEEN PINS 10 AND 14OF IC 35. THIS PROVIDES PULL-UP TO DRIVE THE 7475 LATCH.</p><p>5. THE TRACE TO PIN 8 OF IC 5 (GROUND) HAS BEEN CUT AND ALINE RUN DIRECTLY TO THE GROUND EUS ON THE BOTTOM. THISELIMINATES CROSS-TALK FROM THE NE555 OSCILLATOR.</p><p>6. A 2200 PF CAPCITOR SHOULD BE ADDED BETWEEN PINS 6 AND 8 ONIC 5. THIS REDUCES THE EFFECTS OF HIGH-FREQUENCY NOISEGENERATED IN SOME COMPUTERS.</p><p>INCLUDED ON REVISION D:</p><p>7. ADD A .01 MFD CAPACITOR BETWEEN PINS 15 AND 8 OF IC S.8. ADD A IK RESISTOR BETWEEN PINS 12 AND 14 OF IC 30.9. CONNECT ONE SIDE OF A IX RESISTOR TO 5 VOLTS~ THE OTHER TO</p><p>IC29-7&amp;10~ IC2-14&amp;3&amp;7&amp;10~ IC8-14&amp;3&amp;7.10. CONNECT ONE SIDE OF A IK RESISTOR TO 5 VOLTS~ THE OTHER TO</p><p>IC23-4&amp; 10&amp; 13.II. CONNECT ONE SIDE OF A 1K RESISTOR TO 5 VOLTS~ THE OTHER TO</p><p>IC4-13&amp;10~ IC3-9.12. CONNECT PIN I TO PIN 2 ON IC3.</p><p>THERE HAVE BEEN SEVERAL QUESTIONS REGARDING THE USE OF RATESHIGHER THAN THE STANDARD 167 BYTES PER SECOND. CHANGES AREREQUIRED ON BOTH THE INPUT AND OUTPUT SECTIONS. ON THE INPUTSECTION~ THE POTENTIOMETER THAT IS PROVIDED ON THE BOARD MAYBE ADJUSTED TO CHANGE THE FREQUENCY. ON THE OUTPUT SECTION~ANY OF THREE COMPONENTS MAY BE CHANGED TO CHANGE THE FREQUENCY:R6~ R7~ OR C8. IF YOU WANT TO OPERATE AT TWO FREQUENCIES~ FOREXAMPLE A HIGHER ONE~ AND THE STANDARD~ IT IS FEASIBLE TO INSTALLA SWITCH FOR THE ABOVE ME~lIONED COMPONENTS. FOLLOWING 'OULD BEA REASONABLE PROCEDURE FOR EXPERIMENTING WITH THE HIGHER RATES:</p><p>1. REDUCE THE VALUE OF R6~ R7~ OR C8 BY ABOUT THE AMOUNT YOUWANT TO INCREASE THE FREQUENCY.</p><p>2. USE THE CASSETTE OUTPUT ROUTINE AND A STOP WATCH TO VERIFYTHAT THE INCREASE IN OUTPUT SPEED HAS BEEN ATTAINED.</p><p>3. USE THE SYNC GENERATOR PROGRAM TO MAKE A TAPE WITH A LONGSTREAM OF SYNC BYTES AT THE NEW FREQUENCY.</p><p>4. PLAY IT BACK~ ADUUST ING THE POT FOR THE LED TO COME ON.CLOSER ADJUSTMENT OF THE CASSETTE VOLUME CONTROL MAY ALSOBE NECESSARY.</p><p>5. THE.l CAPACITOR MODIFICATION MENTIONED IN ITEM 3 ABOVE WILLALSO HAVE TO BE REDUCED ACCORDINGLY.</p><p>8</p></li><li><p>SOLDERING, CLEANING, AND INSTALLATION NOTES</p><p>SOLDERING:</p><p>Be sure to use good resin-core solder. Acid-core solder willcorrode. Use a small soldering element, preferably about 27watts. Keep your tip clean by wiping on a sponge. Apply heatto the joint first, then solder, then remove solder, then removethe heat (soldering iron). Don't leave the heat applied to theconnection more than a few seconds at a time. Some of thecomponents can be destroyed b:'l too much heat, especial1;&gt;" theintegrated circuits (IC's). Be sure there is a smoot~l flow ofsolder over the complete connection, and that the joint looksshiny.</p><p>CLEANING:</p><p>After you finish soldering, there will be many small conductiveparticles on the board which you car.....'1ot ahrays see. Take asmall pointed instrument of some so,rt, such as a jeweler'sscrewdriver, and scrape between all printed...</p></li></ul>