Anybody here know anything about throubleshooting the bank-switched memory on an Apple ///?
This machine was working perfectly until I tried upgrading the keyboard to a /// Plus keyboard-- this requires replacing the encoder ROM as well as the keyboard.
Simple enough, but the computer would not boot SOS afterwards. It displays the screen and then crashes. Memory diagnostic tests pass "bank 0" and then die.
I completely replaced all the memory chips (this is a 256K model) with NEC 4164s, and the symptoms did not change. I suspect the problem is in the circuitry that handles the bank switching, but I don't know what to try next. Any suggestions would be appreciated.