PDF edition of FAST6191's GBA and DS Rom hacking guide. It is a guide to graphics (2d and 3d), audio (GBA and DS), text, game logic (assembly, cheating, levels and more) as well as usage of various tools, several example hacks.
Note some images were shrunk to fit nicely on the screen, they should retain their original resolution though and can been zoomed into.
Fixes for typos, layout and (hopefully not) corrections to hacks as well as suggestions for other things to cover or increase coverage of are welcome.