NES 2.0 Mapper 358

NES 2.0 Mapper 358 is used for yet another variation of INES Mapper 090 from J.Y. Company, used on the 1997 Super Game 7-in-1 (JY-016) multicart (PCB number YY860606C), and possibly others. It differs from most other mappers using the J.Y. Company ASIC in the way the outer 512 KiB CHR-ROM bank is selected.

Outer Bank Register ($D003)

Mask: $F803

7654 3210
---- ----
..M. .ppC
  |   ||+-- CHR-ROM A18 if M=0, ignored if M=1
  |   ++--- PRG-ROM A17-A18
  +-------- Outer CHR bank size and selection
             0: Mask to 256 KiB, CHR A18=0
             1: Mask to 512 KiB, CHR A18=1 in 2 KiB CHR banking mode, otherwise CHR A18=0

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