Hi folks,
might need your help on this one.
I've got an Apple //e (enhanced) US with no aux- or extensioncards installed, 1984.
In BASIC, whenever I press the three keys 8 9 0 simultaneously, I get a "-" character in the mix.
This is reliably recreatable (not in the AppleWin emulator, though) and the keyboard is working perfectly otherwise.
If somebody were to fire up their precious Apple //e (preferably in the same configuration)
to confirm or to disprove this behaviour, that would be very helpful.
Thanks a ton
Happens to me too.
Apple II keyboards are not true "n key" rollover. Maybe 1-3 key max. I think this behavior is probably normal.
The keyboard encoder in the apple 2 can only handle one key at a time (and it latches a parallel ASCII byte rather than serially sending up/down scancodes like a PC). Shift, control, and apple keys are special cases and aren't really "real" keys. As a result, I imagine there aren't any blocking diodes on the key switches to keep rows and columns from getting confused when multiple keys are held down, since it can only handle one key at a time anyway.
I been looking into building a board that sits between the keyboard connector on the mainboard and the keyboard ribbon cable, that can make the A2 keyboard send PC-style scancodes over USB to the A2pi card, to get around this single key issue. But the blocking diodes are troublesome; I think I may have to add them to the keyboard itself to make it work. :/
Alright, good to know!
Thanks for the information everyone.