NES 2.0 Mapper 265

NES 2.0 Mapper 265 is used for T-262 multicarts, all of which use 8 KiB of CHR-RAM. It latches both address and data bits. Its UNIF board name is BMC-T-262.

Address latch

Mask: $8000

$8000: A~[1.L. ..OO POO. ..M.]
            |    || |||    +-- Select nametable mirroring. 0=Vertical, 1=Horizontal
            |    ++-|++------- 128 KiB Outer PRG-ROM bank at $8000-$FFFF
            |       +--------- PRG-ROM banking mode
            |                   0: Fixed Inner PRG-ROM bank 7 at $C000-$FFFF (UNROM)
            |                   1: Mirrored Inner PRG-ROM bank, selected by data latch(NROM-128)
            +----------------- Locking bit. 1=Prevent further writes from changing the latched
                               address bits. The data bits, which select the inner PRG bank,
                               are still changeable.
                               

Data latch

Mask: $8000

$8000: 7654 3210
       ---------
       .... .PPP
             +++- Select 16 KiB Inner PRG-ROM bank at $8000-$BFFF,
                  also at $C000-$FFFF if address bit 7==1