NES 2.0 Mapper 287

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NES 2.0 Mapper 287 is used for at least two 4-in-1 multicarts (411120-C, 811120-C). Its UNIF board names are BMC-411120-C and BMC-K-3088. The former has a DIP switch or jumper with a 0/1 setting.

Outer Bank Register ($6000-$7FFF, write)

Mask: $E000

D~7654 3210
  ..II MmOO
    || |+++- Select 128 KiB Outer PRG-ROM/CHR-ROM bank regardless of banking mode
    || |+--- If DIP Switch ==1: Same function as Bit 3
    || ++--- Select PRG Banking Mode
    ||        0: MMC3 Inner Bank, 128 KiB Outer Bank
    ||        1: 32 KiB Inner Bank (Bits 0-1) and 128 KiB Outer Bank
    ++------ Select 32 KiB inner PRG-ROM bank at CPU $8000-$FFFF if Bit 3==0

MMC3-compatible registers ($8000-$FFFF, write)

Mask: $E001

$8000, $8001, $A000, $A001, $C000, $C001, $E000, $E001: As normal MMC3.


  • Because the outer bank register is connected to where WRAM would normally be, WRAM needs to be enabled via bit 7 of MMC3 register $A001 before accessing the outer bank register.