Matrix Keyboard Interface

[Alan Cox]

I've uploaded the RC2014 keyboard adapter to hackaday. It's primarily designed for the ZX81 replacement 8x5 membrane keyboard and has connectors spaced accordingly. You can however build it equally with pin headers and use other matrix keyboards up to 8x8. The ZX81 ones are handy as they are cheap, small and just stick down onto a flat surface. They also capture the authentic lifeless keyboard feel of the period.

For the real pros the membranes are also available in plain black to add your own top mat - or so you can go for the retrocomputing version of the fretless guitar vibe.

https://hackaday.io/project/167449-zx81-keyboard-adapter-for-rc2014

Alan

[David Reese]

I remember years ago building a ZX81 into a project case with a Ti-994A keyboard wired up to provide input.  I went so far as to paint the keycaps with black spray paint and then laminate photocopies of the ZX81 keycap labels on with clear acrylic lacquer.  I forget the name of the little book that inspired the project, but it had a steel-gray trade paper cover and I remember also a schematic for a 24-line I/O board that used an 8255 PPI chip.