NES 2.0 Mapper 260 is used for HP10xx/HP20xx multicarts. It is a predecessor to FK23C, both in its register layout, and the fact that several multicarts exist in HPxx and FK23C versions. Its UNIF board names are BMC-HPxx and BMC-HP2018-A.
Mask: Unknown 7654 3210 --------- .... ..DD ++- DIP Switch Setting
Mask: $F003 7654 3210 --------- L... .MMM | +++- Select banking mode | 0: MMC3: 256 KiB PRG, 256 KiB CHR | 1: MMC3: 256 KiB PRG, 128 KiB CHR | 2: MMC3: 128 KiB PRG, 256 KiB CHR | 3: MMC3: 128 KiB PRG, 128 KiB CHR | 4: NROM-128: 16 KiB PRG (mirrored at $8000 and $C000), 8 KiB CHR | 5: NROM-256: 32 KiB PRG, 8 KiB CHR | 6: CNROM: 32 KiB PRG, 16 KiB CHR | 7: CNROM: 32 KiB PRG, 32 KiB CHR +--------- 1= Lock, do not respond to further writes in the $5xxx range
In MMC3 modes, the final PRG/CHR bank number is the result of masking the MMC3 bank register content according to the specified size (128 or 256 KiB) and OR'ing with the opposite-masked content of the PRG ($5001) and CHR ($5002) Base registers. In the CNROM modes, the inner bank comes from the CNROM Latch (one bit only in 16 KiB CHR mode, two bits in 32 KiB CHR mode) OR'ed with the opposite-masked content of the CHR ($5002) Base register.
Mask: $F003 7654 3210 --------- ..PP PPPP ++-++++- Select 16 KiB PRG Base
Mask: $F003 7654 3210 --------- .PPP PPPP +++-++++- Select 8 KiB CHR Base
Mask: $8000 7654 3210 --------- .... ..LL ++- Select 8 KiB Inner CHR Bank in CNROM modes
Mask: $E001 $8000, $8001, $A000, $A001, $C000, $C001, $E000, $E001: As normal MMC3.
Categories: MMC3-like mappers, Mappers with scanline IRQs, Multicart mappers