iNES Mapper 236 denotes the Realtec 8031 and 8155 circuit boards, used for a number of multicarts with 128 KiB PRG-ROM and 64 KiB CHR-ROM:
A variant of this circuit board with 512 KiB PRG-ROM and 8 KiB of unbanked CHR-RAM is emulated under the same mapper number:
Due to the presence of four solder pads that select one of sixteen displayed game counts, the same ROM is bound to exist with different cartridge codes.
Mask: $C000 A~FEDC BA98 7654 3210 ------------------- 10.. .... ..M. .CCC | +++- CHR A15..A13 (with CHR-ROM) | PRG A19..A17 (without CHR-ROM) +------- Nametable mirroring 0: Vertical 1: Horizontal
Mask: $C000 A~FEDC BA98 7654 3210 ------------------- 11.. .... ..SS .PPP || +++- PRG A16..A14 ++------ PRG Mode 0: UNROM (PRG A14..16=111 when CPU A14=1) 1: Read Solder Pad (like SS=0, plus PRG A0..A3=solder pad value) 2: NROM-256 (PRG A14=CPU A14) 3: NROM-128
Categories: Multicart mappers, INES Mappers