NES 2.0 Mapper 388

NES 2.0 Mapper 388 denotes J.Y. Company's YY841145C and YY850835C circuit boards, used for the multicarts:

• 1996 Super HiK 4-in-1 (JY-056 earlier version)
• 1996 Super HiK 5-in-1 (JY-056 later version)

It uses the J.Y. Company ASIC, has 1 MiB of PRG-ROM and CHR-ROM each, and is similar to NES 2.0 Mapper 386 but has the Outer Bank register bits in a different order. This particular PCB inhibits ROM nametables and Extended Mirroring that would otherwise be enabled via register, similar to INES Mapper 090.

Outer Bank Register ($D003)

Mask: $F003

7654 3210
---- ----
..L. PpCc
  |  |||+- CHR A18, ignored if L=1
  |  ||+-- CHR A19
  |  |+--- PRG A18
  |  +---- PRG A19
  +------- Select outer CHR-ROM bank size
            0: Mask $900x/$A00x to 256 KiB, use c
            1: Mask $900x/$A00x to 512 KiB, ignore c   

For a description of all other registers, see J.Y. Company ASIC.