Kaypro sold a couple hundred thousand units back in the 80's and they have been sitting in attics for the past 30+ years now. So, you can find parted out examples pretty easily. In my case, I bought a couple broken incomplete keyboards on eBay very cheap over the last 5-6 years. These were originally intended to be spare parts for a complete system that I came across almost 10 years ago. So when it came time to find a case for a new Raspberry PI project, they were a pretty easy choice.

The Kaypro II keyboard has a 5v TTL level serial connection to the base computer. Digging through old manuals with schematics and specifications, I found that the interface is setup as 300 baud, no parity, 8 data bits, and 1 stop bit. This could easily be interfaced to a Raspberry PI. So I busted out a PI, connected a 5v tolerant USB TTL serial adapter, and fired up tio serial IO app to see what I got.

It worked first try and I discovered the keyboard sends ASCII characters on the key make. There is not break. For my intended use, that is no big deal. If was planning to build a game machine, that would have been a deal killer.

Connectivity to the keyboard looks like this.

I connected the PI to the keyboard PCB via the existing 6 pin connector. I reused the original connector from the wire harness. The pinout is in the table below.