INES Mapper 153: Difference between revisions
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[[Category:iNES Mappers|153]] | [[Category:iNES Mappers|153]][[Category:Mappers with cycle IRQs|153]][[Category:Mappers with CHR RAM|153]] | ||
iNES Mapper 153 is used for a [[Bandai FCG]] board with an [[Bandai LZ93D50 pinout|LZ93D50 ASIC]] and 8192 bytes of battery-backed WRAM. These 8192 bytes must be denoted as PRG-NVRAM in the [[NES 2.0]] header using byte value $70. Only one game, ''Famicom Jump II: Saikyou no 7-nin'', uses this mapper. | |||
[[ | =Banks= | ||
* CPU $6000-$7FFF: 8 KiB battery-backed WRAM | |||
* CPU $8000-$BFFF: 16 KiB switchable PRG-ROM bank | |||
* CPU $C000-$FFFF: 16 KiB PRG ROM bank, fixed to the last bank | |||
* PPU $0000-$1FFF: 8 KiB unbanked CHR-RAM | |||
=Registers= | |||
==Outer PRG-ROM Bank Select ($8000-$8003 write)== | |||
Mask: $800F | |||
7 bit 0 | |||
---- ---- | |||
xxxx xxxP | |||
| | |||
+-- Select 256 KiB outer PRG-ROM bank at CPU $8000-$FFFF | |||
* The same value must be written to all four registers, or the outer PRG-ROM bank would be switched as the PPU is rendering. | |||
* Because the ASIC's PA12 and PA13 inputs are grounded, only registers $8000-$8003 instead of $8000-$8007 are relevant. | |||
* No CHR banking is available. | |||
==Inner PRG-ROM Bank Select ($8008 write)== | |||
==Nametable Mirroring Type Select ($8009 write)== | |||
==IRQ Control ($800A write)== | |||
==IRQ Latch ($800B-$800C write)== | |||
These four registers function the same way as on [[INES Mapper 016]], submapper 5. | |||
==PRG-RAM Control ($800D write)== | |||
Mask: $800F | |||
7 bit 0 | |||
---- ---- | |||
..E. .... | |||
| | |||
+-------- PRG-RAM Chip Enable (1=Enable) | |||
=Note= | |||
When booting with WRAM filled with zeroes, ''Famicom Jump II'' will freeze with a black screen. Simply soft-resetting the console will then always run the game properly unless WRAM is zeroed out again. | |||
Latest revision as of 18:47, 25 September 2018
iNES Mapper 153 is used for a Bandai FCG board with an LZ93D50 ASIC and 8192 bytes of battery-backed WRAM. These 8192 bytes must be denoted as PRG-NVRAM in the NES 2.0 header using byte value $70. Only one game, Famicom Jump II: Saikyou no 7-nin, uses this mapper.
Banks
- CPU $6000-$7FFF: 8 KiB battery-backed WRAM
- CPU $8000-$BFFF: 16 KiB switchable PRG-ROM bank
- CPU $C000-$FFFF: 16 KiB PRG ROM bank, fixed to the last bank
- PPU $0000-$1FFF: 8 KiB unbanked CHR-RAM
Registers
Outer PRG-ROM Bank Select ($8000-$8003 write)
Mask: $800F
7 bit 0
---- ----
xxxx xxxP
|
+-- Select 256 KiB outer PRG-ROM bank at CPU $8000-$FFFF
- The same value must be written to all four registers, or the outer PRG-ROM bank would be switched as the PPU is rendering.
- Because the ASIC's PA12 and PA13 inputs are grounded, only registers $8000-$8003 instead of $8000-$8007 are relevant.
- No CHR banking is available.
Inner PRG-ROM Bank Select ($8008 write)
Nametable Mirroring Type Select ($8009 write)
IRQ Control ($800A write)
IRQ Latch ($800B-$800C write)
These four registers function the same way as on INES Mapper 016, submapper 5.
PRG-RAM Control ($800D write)
Mask: $800F 7 bit 0 ---- ---- ..E. .... | +-------- PRG-RAM Chip Enable (1=Enable)
Note
When booting with WRAM filled with zeroes, Famicom Jump II will freeze with a black screen. Simply soft-resetting the console will then always run the game properly unless WRAM is zeroed out again.
