When I saw this person building a Raspberry Pi inside a vintage Apple Keyboard, I thought it could be a comfortable way to play Apple II games on a TV. More important, I happen to have an Apple Extended Keyboard II just waiting for such an experiment…
My winter holiday plans did not include going outside, so I wanted to build it with parts I already had. But the hack uses an Arduino Pro Micro (with a little help of the TMK Keyboard Firmware Collection) as a converter between ADB (the interface used by the Apple IIGS and older Macs) and the familiar USB, and I only had a regular Arduino (actually, a Leonardo-compatible clone).
I wasn’t sure that would do the job, so before tearing the keyboard apart, I decided that my first experiment would be an attempt to connect it to my computer.