Michael Black wrote:
It was a neat trick to use the "IBM" keyboard with the Apple II, because if they'd not changed the code in the keyboard, they'd have had to adda CPU at the Apple II to do the IBM to ASCII conversion,
Sure it's easiest to change the software if that is possible. Indeed a "neat trick".
it was too different to be done in simple hardware. But since there was a whole CPU in the kayboard, change the code in it so the keyboard generates ASCII in the first place.
The PC/XT keyboard generated exactly ONE scan-code for each character with a high bit set if it was a "release" event. So a simple PROM can translate an incoming code to ascii. The only trick is to catch SHIFT and CTRL coded and adjust the PROM's address accordingly.
So it is not rocket science, but still a software change is easier. My only point is that it CAN be done in "simple hardware". -Alex.