NES 2.0 Mapper 404

NES 2.0 Mapper 404 denotes the JY012005 MMC1-based multicart circuit board, used only for the 1998 Super HiK 8-in-1 (JY-021B) multicart.

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

Mask: $E000

D~7654 3210
  ---------
  LM.. ?BBb
  ||   |+++- PRG/CHR A19..A17
  ||   +---- Always set to 1 by the menu
  |+-------- 0: PRG A17=MMC1 A17 (256 KiB inner PRG bank)
  |          1: PRG A17=b        (128 KiB inner PRG bank)
  +--------- 1: Lock outer bank register

Power-on value: $00

MMC1-compatible registers ($8000-$FFFF)

Mask: $E000

See MMC1.