A lot of the keyboards were laid out such that the row column values were ASCII 1:1 corospondence for the the non shifted condition. Those that use the Ay, KRO chips this was the rule and also those chips had a ~2500 bit rom to sort out things like shift and alt-chars. Scan codes are a mostly PC invention. Some of the simpler designs like that sold by RS and SWTP did it all with a few peices of TTL and some diodes. Building a parallel interface ASCII keyboard is not that hard. The only hard part is finding a suitable keyboard (keyswitches). I happen to have to keyboards that are not parallel but the serial format is like that of the PCxt with one variation, the keycodes are direct ASCII. The onboard 8035 with 2716 did all the work (key scan, encode and serialize). the same chip with a minor code change could easily do parallel. Out on the net there are PIC based code to translate PS2 keyboard to ASCII serial and even parallel. Allison