INES Mapper 184
This mapper is for a few games which use the Sunsoft-1 mapper on the Sunsoft-K PCB.
- Atlantis no Nazo
- 東海道五十三次
- The Wing of Madoola
It does not include Fantasy Zone (J), despite using the Sunsoft-1 chip; see below.
Despite the mapper existing as a single IC, its functionality is describable using a 74139, a 74174, and a 74157, and so should probably be considered discrete logic.
fwNES, a NES emulator for DOS, originally assigned mapper 122 for this mapper.[1]
7 bit 0
.1HH .LLL
||| |||
||| +++- Select 4k CHR bank from $0000-0FFF
+++------ Select 4k CHR bank from $1000-1FFF; only banks 4-7 selectable;
existing software is well behaved and writes to this with the $40s bit set
This mapper precludes iNES-default RAM because the register is mapped into $6000-7FFF.
Fantasy Zone contains code that’s compatible with both the SUNSOFT-4 PCB described here, and a not-yet-found release on the SUNSOFT-3R PCB with a SUNSOFT-2 ASIC. Because SUNSOFT-3R was already allocated to Mapper 093, that is the preferred way to support this game.
The SUNSOFT-4 PCB instead provides 8 KiB of unbanked CHR-RAM and repurposes the CHR lines for PRG banking instead:
7 bit 0
.... .PPP
|||
+++- Selects 16k PRG @ $8000-BFFF
Bank at $C000-$FFFF is fixed to the last 16k.
You do not need to support this, nor is there any utility in doing so.
This distinction is similar to what happened with mapper 133
- ↑ FWNES98E.TXT, fwNES 0.302b, 1998/11/16, by FanWen Yang