Have an NES game you're particularly fond of? Load it up in the latest fceuxdsp and start playing around with the debugger, RAM/ROM/PPU viewers, trace logger, etc. Try to figure out where the level data is stored in the ROM, how it's loaded into RAM and converted into name tables, how the game logic works, etc.
The NES uses basically a 6502, which is 8-bit and has a limited instruction set, so it's totally grokkable. It's fun since it's a real game, too, instead of some toy example from the web.
I've been spending a few weekend dissecting MCKids[1], trying to dump level images for TCRF, with great results. It's my first time doing this, so it's hard, slow work, but the breakthrough moments are absolutely worth it.
The NES uses basically a 6502, which is 8-bit and has a limited instruction set, so it's totally grokkable. It's fun since it's a real game, too, instead of some toy example from the web.
I've been spending a few weekend dissecting MCKids[1], trying to dump level images for TCRF, with great results. It's my first time doing this, so it's hard, slow work, but the breakthrough moments are absolutely worth it.
[1] https://gitorious.org/mcmapper/mcmapper/blobs/master/main.c