Change sprites in a GB game

[Cortexfou]

Hi,
I want to make a rom hack and change some sprites and musics in a gameboy game (not a pokemon game). How can I do that ?

Thanks

 

[FAST6191]

There was no great unified/alltogether common audio format on the GB/GBC. To that end you get to figure out the format you are using which is not a trivial feat. If you are thinking full remix or injecting something new (even from a sequel/another system) then it is definitely time to figure out the format, if you just need to snip a note or two or maybe change some volumes or get it to play a different track within the game then you can probably get it done without fully working it out. The GB/GBC does have some audio hardware worth speaking of, the general hardware docs for the system are pandocs and available in various places but http://bgb.bircd.org/pandocs.htm will do.

Sprite wise it is the same as every other system. Get a tile editor with formats you care for (most that do more than one system will have GB) and scan through the game, I quite like http://home.arcor.de/minako.aino/TilEd2002/ but tile molester and crystaltile2 and all the others should get something done. If you are good you can use a debugger to trace the particular sprites down, http://bgb.bircd.org/ is probably the main debugging emulator and though it is for the GBA the following teaches good stuff http://www.romhacking.net/documents/361/ . If it is compressed (a possibility on the GB/GBC) then deal with that, the GB/GBC does not have a common BIOS loaded format like the later handhelds but things are a tiny bit more consistent than they might have been on the NES and SNES.