INES Mapper 184: Difference between revisions
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The most significant bit of H is always set in hardware. (i.e. its range is 4 to 7) | The most significant bit of H is always set in hardware. (i.e. its range is 4 to 7) | ||
(There can be no SRAM because the register is mapped into $6000-7FFF) | (There can be no SRAM because the register is mapped into $6000-7FFF) | ||
fwNES, a NES emulator for DOS, originally assigned mapper '''122''' for this.<ref>FWNES98E.TXT, fwNES 0.302b, 1998/11/16, by FanWen Yang</ref> |
Latest revision as of 21:27, 27 May 2020
This is part of a family of Sunsoft mappers used largely by Japanese games: (iNES Mapper 089, iNES Mapper 093, iNES Mapper 184)
This mapper is for a few games which use the Sunsoft-1 mapper.
Fantasy Zone (J), despite using the Sunsoft-1 chip, is more easily emulated by Mapper 093 because it was written to support execution using either the Sunsoft-2 IC and a variant board that used the Sunsoft-1 IC.
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.
Here is the documentation in disch's original style:
Registers: -------------------------- $6000-7FFF: [.HHH .LLL] H = Selects 4k CHR @ $1000 L = Selects 4k CHR @ $0000 The most significant bit of H is always set in hardware. (i.e. its range is 4 to 7) (There can be no SRAM because the register is mapped into $6000-7FFF)
fwNES, a NES emulator for DOS, originally assigned mapper 122 for this.[1]
- ↑ FWNES98E.TXT, fwNES 0.302b, 1998/11/16, by FanWen Yang