NES 2.0 Mapper 302

NES 2.0 Mapper 302 is used for Kaiser's ROM cartridge conversion of the Japanese Famicom Disk System version of Gyruss. Its UNIF board name is UNL-KS7057.

Banks

• CPU $6000-$67FF: 2 KiB switchable PRG-ROM bank
• CPU $6800-$6FFF: 2 KiB switchable PRG-ROM bank
• CPU $7000-$77FF: 2 KiB switchable PRG-ROM bank
• CPU $7800-$7FFF: 2 KiB switchable PRG-ROM bank
• CPU $8000-$87FF: 2 KiB switchable PRG-ROM bank
• CPU $8800-$8FFF: 2 KiB switchable PRG-ROM bank
• CPU $9000-$97FF: 2 KiB switchable PRG-ROM bank
• CPU $9800-$9FFF: 2 KiB switchable PRG-ROM bank
• CPU $A000-$BFFF: 8 KiB fixed PRG-ROM bank #$0D
• CPU $C000-$FFFF: 16 KiB fixed PRG-ROM bank #$07
• PPU $0000-$1FFF: 8 KiB unbanked CHR-RAM

Registers

Mirroring select ($8000-$9FFF)

Mask: unknown, probably $E000

D~7654 3210
  ---------
  .... ...M
          +- Select nametable mirroring type
             0: Vertical
             1: Horizontal

PRG-ROM Bank ($B000-$E003)

Mask: unknown, probably $F003

A~FEDC BA98 7654 3210
  -------------------
  1RRR .... .... ..RN
   |||             |+- 0: Select low nibble
   |||             |   1: Select high nibble
   +++-------------+-- Select register number
                       $B000/$B001: Set 2 KiB PRG-ROM bank at CPU $8000-$87FF
                       $B002/$B003: Set 2 KiB PRG-ROM bank at CPU $8800-$8FFF
                       $C000/$C001: Set 2 KiB PRG-ROM bank at CPU $9000-$97FF
                       $C002/$C003: Set 2 KiB PRG-ROM bank at CPU $9800-$9FFF
                       $D000/$D001: Set 2 KiB PRG-ROM bank at CPU $6000-$67FF
                       $D002/$D003: Set 2 KiB PRG-ROM bank at CPU $6800-$6FFF
                       $E000/$E001: Set 2 KiB PRG-ROM bank at CPU $7000-$77FF
                       $E002/$E003: Set 2 KiB PRG-ROM bank at CPU $7800-$7FFF