Here is code for early A1000 keyboards with the MOS 6570-33/328191-01 keyboard controller IC! My tests have all been great so far.
I also figured out the reboot issue! The A1000 keyboard does not have a separate RESET signal wire, it only has 4 wires on the connector. Also the 4-wire reboot code in this sketch can be applied to my previous A2000 code to make it work on 4-wire A2000 keyboards.
sketch_a1000kbd.ino (6.95 KB)