NES 2.0 Mapper 267

NES 2.0 Mapper 267 is used for the 8-in-1 JY-119 multicart. It consists of an MMC3 clone with an outer bank register at $6000.

MMC3-compatible registers

Mask: $E001

• $8000, $8001, $A000, $A001, $C000, $C001, $E000, $E001: As normal MMC3. Inner PRG banks are limited to 256 KiB, Inner CHR banks to 128 KiB.

Outer Bank ($6000)

Mask: Unknown

7654 3210
---- ----
UUB. .BB.
||+---++-- Select 256 KiB outer PRG-ROM and 128 KiB outer CHR-ROM bank
++-------- Unknown, cleared when the menu is shown, both set once a game has been selected.

Notes

• The initial value of this register must be $00 for the multicart menu to be shown.
• The cart seems to run just fine when ignoring the two unknown bits.