NES 2.0 Mapper 446 denotes Mindkids' SMD172B_FPGA circuit board. It is used for some large multicarts from Pixel Games as well as for homebrew games such as:
D~[L..M MMMM] | +-++++-- Mapper for the FPGA to emulate +---------- 1=Lock supervisor registers until reset
The set of mappers that the FPGA can emulate differs across cartridges and is selected by the NES 2.0 Submapper.
| NES 2.0 Submapper | $5000.0-4 | Mapper |
|---|---|---|
| 0 | 01 | SKROM |
| 1 | 00 | UNROM |
| 1 | 01 | TKROM |
| 1 | 02 | BNROM |
| 1 | 03 | CNROM |
| 1 | 04 | ANROM |
| 1 | 05 | SKROM |
| 1 | 06 | SNROM |
| 1 | 07 | SUROM |
| 1 | 08 | GNROM |
| 1 | 09 | PNROM |
| 1 | 0A | HKROM |
| 1 | 0B | INES Mapper 152 |
| 1 | 0E | TKSROM |
| 1 | 0F | INES Mapper 189 |
| 1 | 10 | INES Mapper 026 |
| 1 | 12 | INES Mapper 022 |
| 1 | 15 | INES Mapper 025 |
| 1 | 18 | INES Mapper 023 |
| 1 | 1A | VRC1 |
| 2 | 00 | UNROM |
| 2 | 01 | TKROM |
| 2 | 02 | BNROM |
| 2 | 03 | CNROM |
| 2 | 04 | ANROM |
| 2 | 05 | SKROM |
| 2 | 06 | SNROM |
| 2 | 07 | SUROM |
| 2 | 08 | GNROM |
| 2 | 09 | TLROM |
| 2 | 0A | HKROM |
| 2 | 0B | INES Mapper 152 |
| 2 | 0D | TKROM |
| 2 | 0E | TKSROM |
| 2 | 0F | INES Mapper 189 |
| 2 | 10 | INES Mapper 026 |
| 2 | 12 | INES Mapper 022 |
| 2 | 15 | INES Mapper 025 |
| 2 | 18 | INES Mapper 023 |
| 2 | 1A | VRC1 |
| 3 | 01 | H3001 |
D~[BBBB BBBB] ++++-++++- PRG A20..A13
D~[BBBB BBBB] ++++-++++- PRG A28..A21
D~[MMMM MMMM] ++++-++++- PRG A20..A13 mask
The register has an inverted meaning in Submapper 2 vs. Submappers 0-1. In Submappers 0-1, an "1" bit means that the Outer Bank bit is used. In Submapper 2, an "1" bit means that the Inner Bank bit is used.
D~[..CC ...M]
|| +- Mirroring (V=1)
++------ Inner CHR-RAM address mask
0x: 256 KiB
10: 128 KiB
11: 32 KiB
The mirroring bit has no effect when selecting an FPGA mapper with software-selectable mirroring.
D~[.... .P..]
+- 1: Write-protect CHR-RAM
D~[...B BBBB]
+-++++- CHR A17..A13
Categories: Multi-ASIC mappers, Mappers with scanline IRQs, Mappers with flash save, Multicart mappers