NES 2.0 Mapper 389 denotes the circuit board of the Caltron 9-in-1 multicart.
Mask: $F000
A~FEDC BA98 7654 3210
-------------------
1000 0000 .PPP P..M
||| | +- Mirroring: 0=Vertical, 1=Horizontal
+++-+---- PRG A15-A18
Power-up value: $00
Mask: $F000
A~FEDC BA98 7654 3210
-------------------
1001 0000 ..CC C.U.
|| | +-- 0=NROM-256, 1=UNROM-064
++-+---- CHR A15-A17
Power-up value: $00
In NROM-256 mode, the Inner Bank register's PRG bits are ignored. In UNROM-064 mode, the Inner Bank register's PRG bits select one of four 16 KiB PRG-ROM banks at CPU $8000-$BFFF, while CPU $C000-$FFFF is hard-wired to inner bank #3, similarly to INES Mapper 081, used by the stand-alone version of the only game using this mode.
Mask: $E000
A~FEDC BA98 7654 3210
-------------------
.... .... .... PPCC
||++- CHR A13-A14
++--- PRG A14-A15 in UNROM-064 mode when CPU A14=0
Power-up value: $00
Categories: Multicart mappers