INES Mapper 156

iNES Mapper 156 is assigned with unlicensed Korean boards using the DAOU ROM Controller DIS23C01 DAOU 245 ASIC from Daou Infosys.

Example games:

• Metal Force
• General's Son
• Koko Adventure (Buzz & Waldog)

Banks

• CPU $6000-$7FFF: 8 KiB RAM
• CPU $8000-$BFFF: 16 KiB switchable PRG ROM bank
• CPU $C000-$FFFF: 16 KiB PRG ROM bank, fixed to the last bank
• PPU $0000-$03FF: 1 KiB switchable CHR ROM bank
• PPU $0400-$07FF: 1 KiB switchable CHR ROM bank
• PPU $0800-$0BFF: 1 KiB switchable CHR ROM bank
• PPU $0C00-$0FFF: 1 KiB switchable CHR ROM bank
• PPU $1000-$13FF: 1 KiB switchable CHR ROM bank
• PPU $1400-$17FF: 1 KiB switchable CHR ROM bank
• PPU $1800-$1BFF: 1 KiB switchable CHR ROM bank
• PPU $1C00-$1FFF: 1 KiB switchable CHR ROM bank

Registers

CHR-ROM Bank Select ($C000-$C00F)

  Upper       Lower
7  bit  0   7  bit  0
---------   ---------
.... ...H   LLLL LLLL
        |   |||| ||||
        +---++++-++++- Select 9-bit bank number for 1 KiB CHR bank

Write to CPU addresses		1KB CHR bank affected
(high 1 bit)	(low 8 bits)
$C004	$C000	$0000-$03FF
$C005	$C001	$0400-$07FF
$C006	$C002	$0800-$0BFF
$C007	$C003	$0C00-$0FFF
$C00C	$C008	$1000-$13FF
$C00D	$C009	$1400-$17FF
$C00E	$C00A	$1800-$1BFF
$C00F	$C00B	$1C00-$1FFF

PRG-ROM Bank Select ($C010)

7  bit  0
---- ----
.... PPPP
     ||||
     ++++-- Select 16 KiB PRG-ROM bank at CPU $8000-$BFFF   

Nametable Mirroring Type Select ($C014)

7  bit  0
---- ----
.... ..MM
       ||
       ++-- Select nametable mirroring type
             00: Vertical
             01: Horizontal
             1x: One-screen, page 0

Mirroring defaults to one-screen.

Notes

• The current description of it is based on FCEUX's implementation. It appears to fully-decode them, but that's probably inaccurate.
• This mapper is similar to INES Mapper 016, but with no IRQ and EEPROM support and supports 512KB CHR.