NES 2.0 Mapper 431: Difference between revisions

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{{DEFAULTSORT:431}}[[Category:Multicart mappers]][[Category:Mappers with CHR RAM]]
{{DEFAULTSORT:431}}[[Category:Multicart mappers]][[Category:Mappers with CHR RAM]]
'''NES 2.0 Mapper 431''' denotes the Realtec '''GN-91B''', use a multicart consisting of two UNROM games.
'''NES 2.0 Mapper 431''' denotes the Realtec '''GN-91B''', used by a multicart consisting of two UNROM games.


==Outer Bank Register ($8000-$BFFF)==
==Outer Bank Register ($8000-$BFFF)==

Revision as of 14:53, 18 December 2021

NES 2.0 Mapper 431 denotes the Realtec GN-91B, used by a multicart consisting of two UNROM games.

Outer Bank Register ($8000-$BFFF)

Mask: $C000

D~7654 3210 (bus conflicts)
  ---------
  ..P. ...M
    |     +- 0: Vertical mirroring
    |        1: Horizontal mirroring
    +--- PRG A17

Inner Bank Register ($C000-$FFFF)

Mask: $C000

D~7654 3210 (bus conflicts)
  ---------
  .... .PPP
        +++- PRG A16..A14 if CPU A14=0