NES 2.0 Mapper 337

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NES 2.0 mapper 337 is used for a 12-in-1 Game Card multicart. Its UNIF board name is BMC-CTC-12IN1.

Banks

  • CPU $6000-$7FFF: 8 KiB fixed PRG-ROM bank #1
  • CPU $8000-$BFFF: 16 KiB switchable PRG-ROM bank
  • CPU $C000-$FFFF: 16 KiB switchable PRG-ROM bank
  • PPU $0000-$1FFF: 8 KiB of unbanked CHR-RAM

Registers

Outer Bank Register ($8000-$BFFF)

Mask: $C000

D~7654 3210
  ---------
  PPMB B...
  |||+-+---- Select 128 KiB outer PRG-ROM bank
  ||+------- Select nametable mirroring type
  ||          0: Vertical
  ||          1: Horizontal
  ++-------- Select PRG-ROM banking mode
              0: NROM-128 (inner bank bit 0 replaced with CPU A14)
              1: NROM-256
              2: UNROM (inner bank fixed to #7 at CPU $C000-$FFFF)
              3: same as 2

CHR-RAM is write-protected in the NROM modes.

Inner Bank Register ($C000-$FFFF)

Mask: $C000

D~7654 3210    A~FEDC BA98 7654 3210
  ---------      -------------------
  .... .BBB      11W. .... .... ....
        |||        +----------------- 1=Write-protect CHR-RAM
        +++- Select 16 KiB outer PRG-ROM bank at CPU $8000-$BFFF/$C000-$FFFF

Similar Mappers

NES 2.0 Mapper 350 is a variant for larger ROM sizes of this mapper.