Gameboy Development Forum / New to Game Boy programming, made a version of Snake
good tips toward stack allocation in gameboy assembly
Pico as Z80 RAM & RAM: Homebrew Retro Computer Part 2 – Maker Hacks
with just a little bit of micropython code. neat!
Russian multiplication - Atari 5200 / 8-bit Programming - AtariAge Forums
expansive thread on how to do multiplication with processors that don't have multiplication instructions