NES 2.0 Mapper 481

NES 2.0 Mapper 481 denotes the Subor 045N PCB, used on at least one educational computer cartridge with two games on it. It's basically 2x128 KiB of UNROM, switched by an outer bank bit.

• 小霸王 2合1꞉ 仓库世家 & 动脑筋

Banks

• CPU 8000-BFFF: Switchable 16 KiB inner bank
• CPU C000-FFFF: Fixed 16 KiB inner bank 7
• PPU 0000-1FFF: 8 KiB unbanked CHR-RAM
• Mirroring: hard-wired to horizontal or vertical

Bank register ($8000-$FFFF, write)

D~[O... .BBB], Address mask: $8000
   |     +++- PRG A17..A14 if CPU A14=0
   |          7 if CPU A14=1
   +--------- PRG A18 regardless of CPU A14

Notes

The common dump of 小霸王 2合1꞉ 仓库世家 & 动脑筋 is a barely-working overdump for INES Mapper 241 that has the first game inaccessible and boots into the middle of the second game without showing its title screen.