Date: Thu, 28 May 2009 11:23:53 -0400
From: Ethan Dicks <ethan.dicks at gmail.com>
I don't know anything about Mac keyboard protocols or
signaling method, but with the modular-jack keyboards (pre-ADB), it's
probably similar enough to what everyone else did (power, ground,
either data+clock or bi-directional data over the 4 wires) that it
shouldn't be too hard to reverse-engineer.
Yes, that's about it. I used a Motorola 68705 single chip micro as a
dongle in the lead between the Mac and the keyboard. It just passed on
packets from the keyboard to the Mac. The Mac never talked to the
keyboard. My Application talked to the dongle and made sure it had the
correct algorithm in it before allowing the user to continue.
If anyone wants the protocol its probably in the source code which I
have somewhere I think, though maybe on Lisa floppy disks (not Twiggy,
I transferred all my data to more modern 360k 3.5 inch diskettes).
Roger