Play Meter

FI !,Uf2£- 3 MotJtl/ CHIP ~000 UNDU rcsr® CH-!PQ) EK.L rJS/ v'E. Of ca f'uLs E Stt.E.c.1+1 C.1 f2{,lllT f.'( @ 8 .5.PDT 5 .3oJnc'H /31t-s I e.. sixteen pins, you can add more compare circuits as in Figure 3. Since there are sixteen pins to test, you need sixteen Exclusive Ors, sixteen switches, etc. Exclusive Or gates come four to the chip. So you need four 7486 chips. Figure 4 is the comparator schematic part one. The 7486 packages are marked L-1 through L-4. As per Figure 1, the outputs of Loc::;1c . Coffl Pft fl.Aro R the 7486 are pins three, six, eight and eleven. Each of these outputs correspond to a pin on the chip under test. These outputs go onto the pulse stretching circuitry which is discussed next month. The 7486's are powered up by connecting alligator-clips to the logic board five-volts and ground. The 1 N4001 diode and the 500mfd capacitor are added for protection. S-1 through S-16 are SPOT switches which determine which pins are being compared. Next month will consist of pulse stretching circuitry description and schematic. Also included will be a complete parts list and information on where to obtain them. HAVE A QUESTION ABOUT GAMES??? All Questions Answered. Write to me at Play Meter, P.O. Box 24170, New Orleans, La. , =----.. . ,------- ' "'.r ----...-+--------' IS°-~,.,+-+. ~ , ' ... .. , :.--- ;. ...---= ' ...---... ' u , -' -----'' : rs-~... a.. ,, 10-1- --=' u l-11 ~ ~=- , 5~ ~ s, " , +-I----. ' •---+--- , ,.. :~~~-rt-t-t-H-TT .s----' , i.----' 7 - - - - -, ' CONIJCC.\ PtU...tMrortc.1,1 PS -tS E;o-o ---.i! iO Pul..5E. ~\tZ."iL~ C.\t2.c...urrt...'{ I z. 3 H lj ~ .. t 7 ' " 1 10 H! II~ 131~ IS"llo LI ~ L 'i I x ro PULSc STR..tt~ C\e(.lll,.I.'( L 06\C. ColY\PAt'Z..PtTcR.(MR..T s, -5,c. 1) 748b Soc.~ET SPOT swrn..\4