This may have been posted elsewhere a long time ago, but I recently learned that trailing 128KB (131072 bytes) of a game.bin file inside an extracted 00000006.app from a NEOGEO VC wad contains the BIOS used by the emulator. You can replace it with a unibios (which is also 128KB) if you want access to some of the features it provides (like in-game cheats, MVS mode, etc). However, you have to change the byte-order / endianness of the BIOS you put in its place. Example (the game.bin in this example is 7209024 bytes):
#7209024 -131072 = 7077952
head -c 7077952 game.bin > game_tmp.bin;
dd if=uni-bios.rom of=uni-bios_wii.rom conv=swab;
cat game_tmp.bin uni-bios_wii.rom > game_with_unibios.bin;
