NES 2.0 Mapper 452

NES 2.0 Mapper 453 denotes the Realtec 8042 multicart circuit board, used for the 3-in-1 1995 World Competitive Champion Edition (DG-002) multicart. It supports both AOROM and UNROM banking modes.

Data Latch ($8000-$FFFF), write

D~[.PpM .BBB]
    |||  +++- PRG A16..A14 in UNROM mode,
    |||       PRG A17..A15 in AOROM mode
    ||+------ Mirroring
    ||         0=V, 1=H in UNROM mode,
    ||         CIRAM A10 in AOROM mode
    ++------- Lock Pp if either bit is set
    |+------- PRG A17 in UNROM mode
    +-------- PRG A18
    +-------- PRG banking mode
               0=UNROM, 1=AOROM