NES 2.0 Mapper 321

From NESdev Wiki
Revision as of 09:18, 14 September 2022 by NewRisingSun (talk | contribs) (Reassign this former mapper 287 duplicate to a mapper 287 variant.)
Jump to navigationJump to search

NES 2.0 Mapper 321 denotes the 820310 MMC3-based multicart circuit board, UNIF MAPR BMC-820310-C. It is basically NES 2.0 Mapper 287 looking at differently-ordered address bits.

Outer Bank Register ($6000-$7FFF, write)

A~[011. .... ..PP MB..], A001.7=1, A001.6=0
               || |+---- PRG/CHR A17
               || +----- 0=PRG A13..A16 from MMC3
               ||        1=PRG A15..A16 from PP,
               ||          PRG A13..A14=CPU A13..A14
               ||          (NROM-256-like PRG banking)
               ++------- PRG A15..A16 is M=1