I've seen 733Wxxx house codes on Xerox chips before, but hav never seen the equivalents list. Wait a second. You said jsut now it has 14 pins, and you give a signal for pin 15. Does it have a top cap or something :-) More seriousyl, if it's actually a 16 pin IC, I would guess it's a programmed 74x188 (open collector) or more likely 74x288 (3-state output) PROM. That's a 32*8 bit device that goes udner a variety of other numbers too, like 18S030. Fiffernt manufacturers had differnt programming algorithms, but the all work the same way in-circuit (in read mode). The pinout is : 1 : D0 2 : D1 3 : D2 4 : D3 5 : D4 6 : D5 7 : D6 8 : Gnd 9 : D7 10 : A0 11 : A1 12 : A2 13 : A3 14 : A4 15 : CE/ 16 : Vcc This could match your device, A4 is tied high (so only useing the second half of the ROM) and only the first 4 data lines are used. Of course the problem for you, I guess, is that a blank chip of the right type is of little use to you. You need to konw the contents (looks to be 16 4-bit words in your case). You could copy it from a working device fro the same type of machine, but other than that uou have some designing to do... -tony