nsus_cif@troi.cc.rochester.edu (Nick Susch) (04/03/91)
Hi, I am working on a project that uses the 74LS688 chip. Unfortunately, I can't find this chip or any information on it, anywhere in Rochester. The schematics I am useing to wire it up also don't say anything about the pin-outs of it. It is called an "8-bit comparitor" and looks like it is used to compare two 8-bit numbers (brilliant deduction, huh? :-) Well, to make this story short, I can easily get two 74LS85 chips (4-bit magnitude comparitors), the only thing is, I need the pin-out of the 74LS688 so I can find out what the functions of the outputs are (low when =, or high, etc...) So can someone who knows the pinout and functioning of the 74LS688 please e-mail it to me? It would be greatly appreciated. Thanks! -- "And when I have understanding | /\/ick Susch - University of Rochester of computers, I will be the | nsus_cif@uhura.cc.rochester.edu supreme being!" | nsus_cif@uordbv.bitnet - Evil (from "Time Bandits") | ... !rochester!ur-cc!nsus_cif
andreww@uniwa.uwa.oz (Andrew John Williams) (04/03/91)
The pinout for the 74LS688 is: -G 1 20 Vcc P0 2 19 -(P=Q) Q0 3 18 Q7 P1 4 17 P7 Q1 5 16 Q6 P2 6 15 P6 Qi Q2 7 14 Q5 P3 8 13 P5 Q3 9 12 Q4 GND 10 11 P4 sorry if that looks a mess. I made a mistake on pin 15 (it should be P6) and since I never really learnt VI all that well I don' know if I fixed it or not. But anyway. How old is your TTL book? My '86 ALS/AS book has it, and I'd guess it was LS for a while before then (I've just had a closer look at the page. Down the bottom it says (c) 1982 Texas Instruments. How old IS your TTL book?!? John West (stealing Andrew's account) and running out of foolish fish quotes