NES 2.0 Mapper 406: Difference between revisions

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NES 2.0 Mapper 406 is used by the homebrew port of ''Haradius Zero''.
[[Category:MMC3-like mappers]][[Category:Mappers with scanline IRQs]][[Category:NES 2.0 mappers with submappers]][[Category:Mappers with flash save]]
'''NES 2.0 Mapper 406''' is used for the homebrew game ''Haradius Zero''. It is basically a homebrew [[TLROM]] circuit board that connects the [[MMC3]]'s address lines differently, and saves the high score to flash ROM. The game executes the flash ROM chip's "Software ID" command; if the manufacturer and model ID do not match the expected values, or it detects that WRAM exists, the game replaces the first level with an unwinnable boss fight.
 
'''Submapper 0''' denotes the 60-pin release of the game (saying "AXR" at the bottom of the title screen). The MMC3's A0 input is actually connected to CPU A1, so that $8000/$8002 rather than $8000/$8001 are differentiated. The Flash ROM chip is a Macronix MX29F040 (manufacturer ID=$C2, model ID=$A4).
 
'''Submapper 1''' denotes the 72-pin release of the game (saying "INL" at the bottom of the title screen). The MMC3's $8xxx and $Exxx registers are swapped, so that $8000/$8001 enables/disable IRQ generation, and $E000/$E001 write to bank registers. The Flash ROM chip is an AMD AM29F040 (manufacturer ID=$01, model ID=$A4).

Latest revision as of 12:21, 23 January 2023

NES 2.0 Mapper 406 is used for the homebrew game Haradius Zero. It is basically a homebrew TLROM circuit board that connects the MMC3's address lines differently, and saves the high score to flash ROM. The game executes the flash ROM chip's "Software ID" command; if the manufacturer and model ID do not match the expected values, or it detects that WRAM exists, the game replaces the first level with an unwinnable boss fight.

Submapper 0 denotes the 60-pin release of the game (saying "AXR" at the bottom of the title screen). The MMC3's A0 input is actually connected to CPU A1, so that $8000/$8002 rather than $8000/$8001 are differentiated. The Flash ROM chip is a Macronix MX29F040 (manufacturer ID=$C2, model ID=$A4).

Submapper 1 denotes the 72-pin release of the game (saying "INL" at the bottom of the title screen). The MMC3's $8xxx and $Exxx registers are swapped, so that $8000/$8001 enables/disable IRQ generation, and $E000/$E001 write to bank registers. The Flash ROM chip is an AMD AM29F040 (manufacturer ID=$01, model ID=$A4).