INES Mapper 228: Difference between revisions
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Revision as of 21:35, 12 August 2011
iNES Mapper 228 represents the board used by Active Enterprises for Action 52 and Cheetahmen II.
Registers
Address Data FEDCBA98 76543210 76543210 1.MHHPPP PPS.CCCC ......CC |||||| ||| |||| || |||||| ||| ++++-------++- Select 8 KiB CHR ROM bank at PPU $0000 |||||| ||+--------------- PRG bank size |||||| || 0: Put bank with bit 0 false in $8000 and |||||| || bank with bit 0 true in $C000 |||||| || 1: Put same 16 KiB bank in $8000 and $C000 |||+++-++---------------- Select 16 KiB PRG ROM bank at CPU $8000 |++---------------------- Select which 512 KiB PRG ROM chip to enable | (A52 uses 0, 1, and 3; bank 2 is open bus) +------------------------ 0: Vertical mirroring; 1: Horizontal mirroring
There are also four 4-bit RAM locations at $4020-$4023, mirrored throughout $4020-$5FFF
References
- Disch's mapper doc