NES 2.0 Mapper 356

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NES 2.0 Mapper 356 is used for the J.Y. Company's 7-in-1 Rockman (JY-208) multicart. It is basically INES Mapper 045 but with added functionality to switch between CHR-ROM and CHR-RAM, and between normal two-screen and four-screen mirroring.

All registers work as INES Mapper 045, except $6000 sequential register 2 (third write):

D~7654 3210
   ||| ++++ CHR-AND block size (see Mapper 45 description)
   ||+----- High bit of CHR-OR (CHR A18, see Mapper 45 description)
   |+------ CHR memory type select
   |         0: CHR-RAM (8 KiB)
   |         1: CHR-ROM
   +------- Nametable memory select
             0: CIRAM (two nametables, mirrored according to MMC3 setting)
             1: Cartridge VRAM (four nametables)

Because unlike the original Mapper 45, there is only one high CHR-OR bit, only 512 KiB of CHR-ROM are supported.