I currently have project trying to recover a 1980s homebuild CP/M computer.
Mostly everything is working, except the keyboard.
I have trouble identifying how it's working as there is neither an internal nor external clock applied.
Of the keyboard's many lines only +5v, GND, a3 (STROBE) and a22-25,c22-25 (Data) are connected to the terminal.
The individual keys simply pull down two lines each. (X0-11 + Y0-7)
As I read it the !OE of the 2716 must be low for the EEPROM to decode the input into a char code, but that line only traces to an unconnected pin (or inputs of other ICs)
Where does the clock come from?
Dito for the strobe line.
The circuit seems rather dead, wherever I put my probe at, even while typing.
Anyone able to help me debug this?