Recently I got an old keyboard from the 1980s, it has a 20 pin ribbon cable connector, weights almost 3kg’s and has no information on Google. This should be fun.
The keyboard in question is a Computervision branded one, though the PCB says it’s an Amkey MPNK-68. Looking at the insides, the date codes on the circuit board are from 1984 and 1985, meaning this keyboard is probably from the end of the 1980s. Taking a look at the keycaps and all the special functions, it was most likely used for a terminal.
Now to reverse engineer it. A few tools are required to do so:
- A multimeter.
- A logic analyzer, like a Saleae Logic.
- Some screwdrivers to take the keyboard apart.
- A power suply, most likely 5V
Very simply put, the steps are as follows:
- Open the keyboard
- See what the pinout of the connector is.
- Power the keyboard.
- Hook up a logic analyzer to all signal pins.
- Figure out how it works, is it a serial protocol, parallel, something else.
- Build a converter using a microcontroller board like an Arduino.