INES Mapper 206: Difference between revisions
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'''iNES Mapper 206''' is a stripped-down version of [[MMC3]] used by Tengen and Namco. | '''iNES Mapper 206''' is a stripped-down version of [[MMC3]] used by Tengen and Namco. | ||
Chips used include "Tengen MIMIC-1" and "Namcot 118", and the cartridge boards used with this mapper are NES-[[DxROM]]. | |||
Many ROMS using this mapper are incorrectly listed as using MMC3, but will usually work if emulated with MMC3, and the mirroring is correct, as if they were on a [[TxROM|TEROM or TFROM board]]. | |||
Compared to MMC3: | Compared to MMC3: | ||
Revision as of 16:36, 26 October 2011
iNES Mapper 206 is a stripped-down version of MMC3 used by Tengen and Namco. Chips used include "Tengen MIMIC-1" and "Namcot 118", and the cartridge boards used with this mapper are NES-DxROM. Many ROMS using this mapper are incorrectly listed as using MMC3, but will usually work if emulated with MMC3, and the mirroring is correct, as if they were on a TEROM or TFROM board.
Compared to MMC3:
- There are no IRQs
- There is no WRAM support
- PRG always has the last two 8k banks fixed to the end.
- CHR always gives the left pattern table (0000-0FFF) the two 2k banks, and the right pattern table (1000-1FFF) the four 1k banks.
- Mirroring is hardwired, one game uses 4-screen mirroring (Gauntlet).
- CHR size limit is 64k, PRG size limit is 128k.
Registers:
- $8000: 00000xxx - Select which internal register gets written by $8001
- $8001: 00xxxxxx - Value written to the internal register. PRG registers use only 4 bits.
Internal registers:
- 0, 1: 2k CHR banks at 0000, 0800. Least significant bit is ignored.
- 2, 3, 4, 5: 1k CHR banks at 1000, 1400, 1800, 1C00.
- 6, 7: 8k PRG banks at 8000, A000.
References
- FCEUX source code
