NES 2.0 mapper 337 is used for a 12-in-1 Game Card multicart. Its UNIF board name is BMC-CTC-12IN1.
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
1: NROM-256 (inner bank bit 0 replaced with CPU A14)
2: UNROM (inner bank fixed to #7 at CPU $C000-$FFFF)
3: same as 2
CHR-RAM is write-protected in the NROM modes.
Mask: $C000
D~7654 3210 A~FEDC BA98 7654 3210
--------- -------------------
.... .BBB 11W. .... .... ....
||| +----------------- 1=Write-protect CHR-RAM
+++- Select 16 KiB inner PRG-ROM bank at CPU $8000-$BFFF/$C000-$FFFF
NES 2.0 Mapper 350 is a variant for larger ROM sizes of this mapper.
Categories: Mappers with CHR RAM, Multicart mappers