INES Mapper 055

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:

• Fly Merio Bros.
• Super Mario Bros. Malee 2
• 天才瑪琍 (Tiāncái Mǎlí, a.k.a. Genius Mario)

It adds 2 KiB of PRG-ROM and PRG-RAM each to a regular NROM-256 PCB, but has no bankswitching functionalities.

Banks

• CPU $6000-$6FFF: 2 KiB PRG-ROM, mirrored once
• CPU $7000-$7FFF: 2 KiB PRG-RAM, mirrored once
• CPU $8000-$FFFF: 32 KiB PRG-ROM
• PPU $0000-$1FFF: 8 KiB CHR-ROM

ROM layout

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.