[MAPPER] Unique MMC3 variant

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ExtraOrdinary
Posts: 20
Joined: Mon Jun 02, 2014 7:47 pm
Location: Cairo, Egypt

[MAPPER] Unique MMC3 variant

Post by ExtraOrdinary »

Hello, everybody..

I received several Famiclones over the last year.. I noticed nothing interesting except for a multicart that uses a modified MMC3 to support 512 KiB CHR-ROM in a single pirate game. The mapper uses register $8000.7 bit to choose between a regular MMC3 behaviour if bit 7 clear, or to use two separate 256 KiB CHR ROMs depending on PPU address (First 4 kilobytes for BG mapped from a separate bank from Sprite graphics?). Mapper 004 assumes A12 inversion, so the emulators give scrambled tiles either on BG or sprites.

I checked the list on wiki and the list of variants by Lidnariq that extend CHR-ROM beyond 256 KiB, but I think I missed something..

Any ideas?
NewRisingSun
Posts: 1510
Joined: Thu May 19, 2005 11:30 am

Re: [MAPPER] Unique MMC3 variant

Post by NewRisingSun »

Mappers 121 or 187.
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