His custom PCB mates to the factory parts perfectly, and the USB cable between the button and the computer even fits ... PCB design files for [Glen]’s small keyboards are available on GitHub.

The newest Raspberry Pi 400 almost-all-in-one computer is very, very slick. Fitting in the size of a small portable keyboard, it’s got a Pi 4 processor of the 20% speedier 1.8 GHz variety ...