INES Mapper 246: Difference between revisions
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(→PRG-ROM bank select ($6000-$6003), write: it's 16 specific addresses, not the 28 byte region) |
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|| ++-++++- PRG A18..A13 of bank to select | || ++-++++- PRG A18..A13 of bank to select | ||
++--------------- CPU A14..A13 bank to switch | ++--------------- CPU A14..A13 bank to switch | ||
* When reading from CPU address $FFE4-$FFFF, PRG A17 is forced high, as if register $6003 were OR'd with $10. | * When reading from CPU address $FFE4-$FFE7, $FFEC-$FFEF, $FFF4-$FFF7, or $FFFC-$FFFF, PRG A17 is forced high, as if register $6003 were OR'd with $10. | ||
* Register $6003 is set to $FF at power-on | * Register $6003 is set to $FF at power-on only. | ||
==CHR-ROM bank select ($6004-$6007), write== | ==CHR-ROM bank select ($6004-$6007), write== | ||
A~[0110 0000 000. .1rr] D~[bbbb bbbb] | A~[0110 0000 000. .1rr] D~[bbbb bbbb] | ||
Latest revision as of 16:30, 7 September 2024
iNES Mapper 246 denotes the G0151-1 circuit board, used only for the Taiwanese game 封神榜 (Fēngshénbǎng: Fúmó Sān Tàizǐ).
Banks
- CPU $6800-$6FFF: 2 KiB PRG-RAM, battery-banked
- CPU $8000-$9FFF: 8 KiB PRG-ROM bank, switchable via $6000
- CPU $A000-$BFFF: 8 KiB PRG-ROM bank, switchable via $6001
- CPU $C000-$DFFF: 8 KiB PRG-ROM bank, switchable via $6002
- CPU $E000-$FFFF: 8 KiB PRG-ROM bank, switchable via $6003
- PPU $0000-$07FF: 2 KiB CHR-ROM bank, switchable via $6004
- PPU $0800-$0FFF: 2 KiB CHR-ROM bank, switchable via $6005
- PPU $1000-$17FF: 2 KiB CHR-ROM bank, switchable via $6006
- PPU $1800-$1FFF: 2 KiB CHR-ROM bank, switchable via $6007
Nametable mirroring is hard-wired and set by the iNES header.
Registers
PRG-ROM bank select ($6000-$6003), write
A~[0110 0000 000. .0rr] D~[..bb bbbb]
|| ++-++++- PRG A18..A13 of bank to select
++--------------- CPU A14..A13 bank to switch
- When reading from CPU address $FFE4-$FFE7, $FFEC-$FFEF, $FFF4-$FFF7, or $FFFC-$FFFF, PRG A17 is forced high, as if register $6003 were OR'd with $10.
- Register $6003 is set to $FF at power-on only.
CHR-ROM bank select ($6004-$6007), write
A~[0110 0000 000. .1rr] D~[bbbb bbbb]
|| ++++-++++- CHR A18..A11 of bank to select
++--------------- PPU A12..A11 bank to switch
See also
- http://forums.nesdev.org/viewtopic.php?t=13969 Why does Fong Shen Bang only work in Famiclones?
