INES Mapper 084
iNES Mapper 084 appears to have two conflicting allocations.
neshdr20.txt by VmprHntrD claims the mapper as reserved for Pasofami, an emulator made by Nobuyuki Andou. MAME’s source reflects this but does not include any code to handle it.
fwNES 0.30 replaced the Pasofami mapper assignment with “PC-SMB2J” (PC = Pirate Cart) used by “SMBJ2”.[1] The name is also given as “PC-Super Mario Bros 2 J Custom Mapper” and “Super Mario Bros. 2J (HK hacked)” in other mapper lists for the emulator.[2][3]
Details are unknown, however the implementation in fwNES appears to be different from other FDS conversion mappers such as iNES Mapper 40, 50 or 142.
(TODO: Register documentation & comparison with equivalent handling in Pasofami - it’s possible that this is still the Pasofami mapper implementation)
At some point, FCEUX lost support for this mapper.[citation needed]
Currently a few registers of fwNES’ implementation were discovered:
Bank Map:
CPU $6000-$7FFF - PRG-RAM Bank
CPU $8000-$9FFF - Switchable PRG-ROM Bank
CPU $A000-$BFFF - Switchable PRG-ROM Bank
CPU $C000-$DFFF - Switchable PRG-ROM Bank
CPU $E000-$FFFF - Switchable PRG-ROM Bank
PPU $0000-$03FF - Switchable CHR-ROM Bank
PPU $0400-$07FF - Switchable CHR-ROM Bank
PPU $0800-$0BFF - Switchable CHR-ROM Bank
PPU $0C00-$0FFF - Switchable CHR-ROM Bank
PPU $1000-$13FF - Switchable CHR-ROM Bank
PPU $1400-$17FF - Switchable CHR-ROM Bank
PPU $1800-$1BFF - Switchable CHR-ROM Bank
PPU $1C00-$1FFF - Switchable CHR-ROM Bank
Registers (Write):
Unless otherwise mentioned, these register aren't mirrored at any other addresses.
$8000 - Set 8 KiB PRG-ROM Bank at CPU $8000-$9FFF
$8001 - Set 8 KiB PRG-ROM Bank at CPU $A000-$BFFF
$8002 - Set 8 KiB PRG-ROM Bank at CPU $C000-$DFFF
$8003 - Set 8 KiB PRG-ROM Bank at CPU $E000-$FFFF
$A000 - Set 1 KiB CHR-ROM Bank at PPU $0000-$03FF
$A001 - Set 1 KiB CHR-ROM Bank at PPU $0400-$07FF
$A002 - Set 1 KiB CHR-ROM Bank at PPU $0800-$0BFF
$A003 - Set 1 KiB CHR-ROM Bank at PPU $0C00-$0FFF
$A004 - Set 1 KiB CHR-ROM Bank at PPU $1000-$13FF
$A005 - Set 1 KiB CHR-ROM Bank at PPU $1400-$17FF
$A006 - Set 1 KiB CHR-ROM Bank at PPU $1800-$1BFF
$A007 - Set 1 KiB CHR-ROM Bank at PPU $1C00-$1FFF
$C002 - IRQ Disable (?)
$C003 - IRQ Enable (?)
$D000 - Set Nametable Arrangement
$E000 - IRQ Count Enable (Bit 0 = Enable) (?)
- ↑ WHATSNEW.TXT & FWNES98E.TXT, fwNES 0.302b, 1998/11/16, by FanWen Yang
- ↑ https://web.archive.org/web/20000818031458fw_/http://fwnes.vintagegaming.com/mappers.htm
- ↑ https://web.archive.org/web/20000818031534fw_/http://fwnes.vintagegaming.com/faq-mppr.txt