INES Mapper 122: Difference between revisions
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NewRisingSun (talk | contribs) (Redirected page to INES Mapper 184) |
NewRisingSun (talk | contribs) (Reuse mapper 122 for JY043, separated from KS-7058 (now 001.7), so that mapper 171 can solely denote BBK.) Tag: Removed redirect |
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{{DEFAULTSORT:122}}[[Category:iNES Mappers]]'''iNES Mapper 122''' denotes the '''JY043''' circuit board, a simpler bootleg variant of Kaiser's [[MMC1|KS-7058]] circuit board. | |||
=Overview= | |||
* CPU $8000-$FFFF: 32 KiB unbanked PRG-ROM | |||
* PPU $0000-$0FFF: 4 KiB switchable window into 32 KiB CHR-ROM | |||
* PPU $1000-$1FFF: 4 KiB switchable window into 32 KiB CHR-ROM | |||
* Nametable arrangement: Selected via solder pad | |||
=Registers= | |||
There are two writable registers in the CPU $8000-$FFFF address range. | |||
'''Register 1: Responds to even addresses from CPU $8000-$FFFE''' | |||
D~[.... .CBA] A~[1... .... .... ...0] | |||
+++- 4 KiB CHR-ROM bank (CHR A14..A12) | |||
for PPU $0000-$0FFF | |||
'''Register 2: Responds to odd addresses from CPU $8001-$FFFF''' | |||
D~[.... .CBA] A~[1... .... .... ...1] | |||
+++- 4 KiB CHR-ROM bank (CHR A14..A12) | |||
for PPU $1000-$1FFF | |||
=Notes= | |||
* iNES Mapper 122 had at one time been used by the DOS-based fwNES emulator to denote Sunsoft-1, now assigned to [[INES Mapper 184|Mapper 184]]. | |||
* JY043 had previously been assigned together with KS-7058 and the BBK Keyboard Famiclone's mapper as [[INES Mapper 171]]. | |||
Latest revision as of 09:19, 17 January 2025
iNES Mapper 122 denotes the JY043 circuit board, a simpler bootleg variant of Kaiser's KS-7058 circuit board.
Overview
- CPU $8000-$FFFF: 32 KiB unbanked PRG-ROM
- PPU $0000-$0FFF: 4 KiB switchable window into 32 KiB CHR-ROM
- PPU $1000-$1FFF: 4 KiB switchable window into 32 KiB CHR-ROM
- Nametable arrangement: Selected via solder pad
Registers
There are two writable registers in the CPU $8000-$FFFF address range.
Register 1: Responds to even addresses from CPU $8000-$FFFE
D~[.... .CBA] A~[1... .... .... ...0]
+++- 4 KiB CHR-ROM bank (CHR A14..A12)
for PPU $0000-$0FFF
Register 2: Responds to odd addresses from CPU $8001-$FFFF
D~[.... .CBA] A~[1... .... .... ...1]
+++- 4 KiB CHR-ROM bank (CHR A14..A12)
for PPU $1000-$1FFF
Notes
- iNES Mapper 122 had at one time been used by the DOS-based fwNES emulator to denote Sunsoft-1, now assigned to Mapper 184.
- JY043 had previously been assigned together with KS-7058 and the BBK Keyboard Famiclone's mapper as INES Mapper 171.
