[5-]

all of game boy advance and nintendo ds hardware is exhaustively documented in a single text file:

https://problemkaputt.de/gbatek.txt

(but you can replace txt with htm for a fancier version)

this ranges from physical description to compact arm instruction set reference -- you really only need this document (and a way to get your console to run your code!) to program completely from scratch.

i've picked up a dsi because it can load code from an sd card, so only the console, an sd card and a computer is required for programming it, but see https://news.ycombinator.com/item?id=47706877 further down this thread for the case for preferring the gba.

[medbar]

Whoah, this is great! Thanks for sharing