I did some awesome hacks of Excitebike back in the day. I was able to hack in my own levels and race on them . Heh, anyway... I believe this: http://nesdev.parodius.com/ will be extremely useful, although that's got a lot of technical stuff... so maybe this: http://www.nesplayer.com/database/in...oc/romdoc.html will help if you're really a beginner. And zophar.net should have some hacks that you could download so you could compare those to the originals to see what was changed (learning by example), and they have tools and other stuff that might be useful.

DogP