NES 2.0 Mapper 467

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Revision as of 12:05, 5 April 2022 by NewRisingSun (talk | contribs) (Created page with "{{DEFAULTSORT:467}}Category:Multicart mappersCategory:MMC3-like mappersCategory:Mappers with scanline IRQs'''NES 2.0 Mapper 467''' denotes the '''47-2''' MMC3-based circuit board, used for a ''72-in-1'' multicart. It is effectively INES Mapper 197 submapper 0 with an outer bank register and an NROM mode. ==Outer Bank Register ($9000, write)== Mask: $F000? D~[MSNQ QPPp] ||++-++++- PRG A18..A14 ||+------- PRG banking mode || 0=...")
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NES 2.0 Mapper 467 denotes the 47-2 MMC3-based circuit board, used for a 72-in-1 multicart. It is effectively INES Mapper 197 submapper 0 with an outer bank register and an NROM mode.

Outer Bank Register ($9000, write)

Mask: $F000?

D~[MSNQ QPPp]
   ||++-++++- PRG A18..A14
   ||+------- PRG banking mode
   ||          0=NROM-128
   ||          1=MMC3-based
   |+-------- PRG (if N=1)/CHR banking mode
   |           0=PRG A14..A13 from MMC3, PRG A19..A15 from NQQPP
   |             CHR A12..A10=PPU A12..A10, CHR A18..A13 from MMC3 CHR A17..A12, CHR A19=0
   |           1=PRG A16..A13 from MMC3, PRG A19..A17 from NQQ
   |             CHR A10=PPU A10, CHR A18..A11 from MMC3 CHR A17..A10, CHR A19=1
   +--------- Nametable mirroring
               0=Vertical
               1=Horizontal

The MMC3 clone ignores the PRG/CHR inversion bits D6 and D7 in the pointer register $8000, and its mirroring output is ignored in favor of the Outer Bank Register's.