INES Mapper 142: Difference between revisions
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[[iNES Mapper 142]] represents a PCB used for several of Kaiser's unlicensed ports of FDS games. Its UNIF board name is '''UNL-KS7032''', and it features the [[VRC3 pinout|KS202 ASIC]], which is an upgrade to Konami's [[VRC3]]. | {{DEFAULTSORT:142}}[[Category:Mappers with cycle IRQs]][[Category:iNES Mappers]][[Category:ASIC mappers]][[Category:FDS conversion mappers]][[Category:Mappers with CHR RAM]][[iNES Mapper 142]] represents a PCB used for several of Kaiser's unlicensed ports of FDS games. Its UNIF board name is '''UNL-KS7032''', and it features the [[VRC3 pinout|KS202 ASIC]], which is an upgrade to Konami's [[VRC3]]. | ||
== Banks == | == Banks == | ||
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=== IRQ Enable ($C000-$CFFF) === | === IRQ Enable ($C000-$CFFF) === | ||
Kaiser's SMB2J writes $02 or $05 to enable, and $00 to disable, indicating that bits 1 and 2 may function similarly to the VRC3. | |||
=== IRQ Acknowledge ($D000-$DFFF) === | === IRQ Acknowledge ($D000-$DFFF) === | ||
Any write to this register will acknowledge the pending IRQ, like VRC3 | Any write to this register will acknowledge the pending IRQ, like VRC3. Unlike a VRC3, $C000 bit 0 must not be moved to bit 1, otherwise SMB2J will freeze. | ||
=== Bank select ($E000-$EFFF) === | === Bank select ($E000-$EFFF) === | ||
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+++- Specify which bank register to update on next write to Bank Data register | +++- Specify which bank register to update on next write to Bank Data register | ||
1: Select 8 KB PRG bank at CPU $8000-$9FFF | 1: Select 8 KB PRG bank at CPU $8000-$9FFF | ||
2: Select 8 KB PRG bank at CPU $A000-$BFFF | 2: Select 8 KB PRG bank at CPU $A000-$BFFF | ||
3: Select 8 KB PRG bank at CPU $C000-$DFFF | 3: Select 8 KB PRG bank at CPU $C000-$DFFF | ||
4: Select 8 KB PRG bank at CPU $6000-$7FFF | 4: Select 8 KB PRG bank at CPU $6000-$7FFF | ||
5 | 6: Writes to $F000 have no effect | ||
0,5,7: unknown | |||
=== Bank data ($F000-$FFFF) === | === Bank data ($F000-$FFFF) === | ||
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== See also == | == See also == | ||
* [//forums.nesdev.org/viewtopic.php?p=242685#p242685 PCB photos] | * [//forums.nesdev.org/viewtopic.php?p=242685#p242685 PCB photos] | ||
* [[iNES Mapper 056]] augments this ASIC with some additional hardware | |||
Latest revision as of 20:19, 2 October 2019
iNES Mapper 142 represents a PCB used for several of Kaiser's unlicensed ports of FDS games. Its UNIF board name is UNL-KS7032, and it features the KS202 ASIC, which is an upgrade to Konami's VRC3.
Banks
- CPU $6000-$7FFF: 8 KB switchable PRG ROM bank
- CPU $8000-$9FFF: 8 KB switchable PRG ROM bank
- CPU $A000-$BFFF: 8 KB switchable PRG ROM bank
- CPU $C000-$DFFF: 8 KB switchable PRG ROM bank
- CPU $E000-$FFFF: 8 KB PRG ROM bank, fixed to the last bank.
- PPU $0000-$1FFF: 8 KB CHR RAM, unbanked
Registers
IRQ Reload value ($8000-$BFFF)
Writes set IRQ reload value, in four four-bit words, same as VRC3
IRQ Enable ($C000-$CFFF)
Kaiser's SMB2J writes $02 or $05 to enable, and $00 to disable, indicating that bits 1 and 2 may function similarly to the VRC3.
IRQ Acknowledge ($D000-$DFFF)
Any write to this register will acknowledge the pending IRQ, like VRC3. Unlike a VRC3, $C000 bit 0 must not be moved to bit 1, otherwise SMB2J will freeze.
Bank select ($E000-$EFFF)
Select one of four bank registers to update on next write to $F000.
7 bit 0
---- ----
.... .RRR
|||
+++- Specify which bank register to update on next write to Bank Data register
1: Select 8 KB PRG bank at CPU $8000-$9FFF
2: Select 8 KB PRG bank at CPU $A000-$BFFF
3: Select 8 KB PRG bank at CPU $C000-$DFFF
4: Select 8 KB PRG bank at CPU $6000-$7FFF
6: Writes to $F000 have no effect
0,5,7: unknown
Bank data ($F000-$FFFF)
7 bit 0
---- ----
.... DDDD
||||
++++- New bank value, based on last value written to Bank select register (mentioned above)
See also
- PCB photos
- iNES Mapper 056 augments this ASIC with some additional hardware
