NES 2.0 Mapper 390

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Revision as of 19:53, 7 October 2019 by NewRisingSun (talk | contribs) (Created page with "{{DEFAULTSORT:390}}Category:Multicart mappers '''NES 2.0 Mapper 390''' denotes the Realtec '''8031''' multicart PCB. ==CHR and Mirroring Select ($8000-$BFFF, write)== Ma...")
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NES 2.0 Mapper 390 denotes the Realtec 8031 multicart PCB.

CHR and Mirroring Select ($8000-$BFFF, write)

Mask: $C000

A~FEDC BA98 7654 3210
  -------------------
  10.. .... ..M. CCCC
              |  ++++- CHR A13..A16
              +------- Mirroring
                        0=Vertical
                        1=Horizontal

PRG and Mode Select ($C000-$FFFF, write)

Mask: $C000

A~FEDC BA98 7654 3210
  -------------------
  11.. .... ..MM Pppp
              || ++++- PRG A14..A17
              ++------ PRG Mode
                       0: UNROM (ppp=7 when CPU A14=1)
                       1: UNROM, PRG A0-A3 OR'd with solder pad value
                       2: Unused, maybe NROM-256?
                       3: NROM-128, ppp unmodified