NES 2.0 Mapper 322

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NES 2.0 Mapper 322 is used for the 35-in-1 (K-3033) multicart. Its UNIF board name is BMC-K-3033.

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

Mask: $E000

A~FEDC BA98 7654 3210
  011. .... SONO OIII
            |||| |+++- Select 16 KiB Inner PRG-ROM bank in NROM mode
            |+|+-+---- Select Outer Bank Number (size depends on mode)
            | +------- Select NROM/other mode
            |           0: NROM mode. Outer PRG-ROM/CHR-ROM bank size is 128 KiB. CHR banks still from MMC3.
            |              Bits 0-2 select inner PRG-ROM bank. 
            |              Inner banks 0 and 4: NROM-128.
            |              Inner banks 1-3, 5-7: NROM-256, bit 0 replaced with CPU A14.
            |           1: MMC3 PRG mode. Bit 7 selects outer bank size.
            +--------- Outer Bank size for MMC3 PRG mode
                        0: 128 KiB outer PRG-ROM and CHR-ROM bank size
                        1: 256 KiB outer PRG-ROM and CHR-ROM bank size

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.