NES 2.0 Mapper 533

From NESdev Wiki
Revision as of 08:42, 29 September 2018 by NewRisingSun (talk | contribs)
Jump to navigationJump to search

NES 2.0 Mapper 533 is used for the Sachen 3014 board, used for the game 動動腦 II: 國中英文(一) (Dòngdòngnǎo II: Guózhōng Yīngwén (I), also known as Middle School English II, SA-003). It's a CNROM-like board with the added ability to read back the latch content for protection purposes.

Banks

  • CPU $8000-$FFFF: Fixed 32 KiB PRG-ROM bank
  • PPU $0000-$1FFF: Switchable 8 KiB CHR-ROM bank
  • Mirroring: hard-wired

Registers

CHR Bank Select and Latch Write ($8000-$FFFF, write)

Mask: $8000

D~7654 3210
  ---------
  LLLl ....
  ++++------ Set latched value that can be read back at $E000-$EFFF
     +------ Select 8 KiB CHR-ROM bank at PPU $0000-$1FFF

Latch Read ($E000-$EFFF, Read)

Mask: $F000

D~7654 3210
  ---------
  .... LLLL
       ++++- Latched value previously written to D4-D7 of $8000-$FFFF

Notes

  • The board is subject to bus conflicts when writing (and possibly when reading).