other weird device stuff that makes programming fun:
Raspberry Pi Pico's PIOs!!!
it's so incredibly powerful and that's so surprising when you consider it's limitations (only 9 CPU instructions? no arithmetic except `JMP x--`? only 32 instructions to share among 4 PIOs? and we could make it output a VGA signal with just that!)
I want to learn OS dev to make a distributed OS for a stack of $5 Pico's
and given that we have VGA output implemented, it can even have an UI