iNES Mapper 055 is used for the UNIF board BTL-MARIO1-MALEE2, used by several bootleg versions of the first Super Mario Brothers that add a great number of cheats:
It adds 2 KiB of PRG-ROM and PRG-RAM each to a regular NROM-256 PCB, but has no bankswitching functionalities.
Nestopia expects Mapper 055 ROM images to first contain the 32 KiB of PRG-ROM at $8000-$FFFF, then the data for the 2 KiB of PRG-ROM at $6000, appropriately padded or repeated to fit into the 16 KiB iNES bank size, for a total of three 16 KiB PRG-ROM banks.
Categories: INES Mappers