NES 2.0 Mapper 314

NES 2.0 Mapper 314 is used for the 32-in-1 Y2K, 64-in-1 Y2K and 76-in-1 Y2K multicarts. Its UNIF board name is BMC-64in1NoRepeat. It exists in both CHR-ROM and unbanked 8 KiB CHR-RAM variants.

Miscellaneous register ($5000, write)

Mask: Unknown, probably $F003

D~7654 3210
  ---------
  U.M. .CC.
  | |   ++- Bits 0-1 of 8 KiB CHR-ROM bank at PPU $0000-$1FFF
  | +------ Select nametable mirroring type
  |          0: Vertical
  |          1: Horizontal
  +-------- 0: UNROM
            1: NROM

Power-on value: $80

PRG-ROM register ($5001, write)

Mask: Unknown, probably $F003

D~7654 3210
  ---------
  MpPP PPPP
  ||++-++++- Select 32 KiB PRG-ROM bank at CPU $8000-$FFFF
  |+-------- Select 16 KiB PRG-ROM bank at CPU $8000-$BFFF and
  |          CPU $C000-$FFFF if M==0
  +--------- Select PRG banking mode
              0: NROM-128
              1: NROM-256

Power-on value: $43

CHR-ROM mode ($5002, write)

Mask: Unknown, probably $F003

D~7654 3210
  ---------
  .... CCCC
       ++++- Bits 2-5 of 8 KiB CHR-ROM bank at PPU $0000-$1FFF

Power-on value: $00

UNROM Latch ($8000-$FFFF, write)

Mask: $8000

D~7654 3210
  ---------
  .... .CCC
        +++- Select 16 KiB PRG-ROM bank at CPU $8000-$BFFF

Power-on value: $00