Has anyone built their own Apple 2 expansion card and programmed it to do something?
If it wouldn't be ridiculously hard, I would like to try etching a circuit board to plug into one of the expansion slots on my 2e. The board would contain a single relay, which could be opened or closed from BASIC code (or if it is not possible from BASIC, from 6502 assembly).
I'd also like to have the board contain 2 leads that the computer could tell when they are connected together.
Maybe later I would expand the # of relays or leads, or build an additional card or two with these same components, for more "inputs" and "outputs".
Any information would be appreciated...
Thanks
You might do better to post your question on the Classic Computer Email list. Information at http://www.classiccmp.org/mailman/listinfo/cctalk
A good book to start with can be found on my site here:
http://8bitsystem.com/AppleII/apple_interfacing.pdf