NES 2.0 Mapper 293

NES 2.0 Mapper 293 is used for the NewStar 12-in-1 and 76-in-1 multicarts. Both use 8 KiB of unbanked CHR-RAM rather than CHR-ROM.

Registers

First Banking Register ($8000-$9FFF, $C000-$DFFF)

Mask: $A000

7654 3210
---------
.... PIII
     |+++- Select inner 16 KiB PRG-ROM bank
     +---- Bit 1 of the PRG banking mode number

Second Banking Register ($8000-$BFFF)

Mask: $C000

7654 3210
---------
MP10 ...2
||++----+- Select outer 128 KiB PRG-ROM bank (note the bit distribution)
|+-------- Bit 0 of the PRG banking mode number
+--------- Select nametable mirroring type
            0: Vertical
            1: Horizontal

PRG banking modes

• 0 (UNROM)

$8000-$BFFF: Switchable 16 KiB Inner PRG-ROM bank

$C000-$FFFF: Fixed 16 KiB Inner PRG-ROM bank #7

• 1

$8000-$BFFF: Switchable 16 KiB Inner PRG-ROM bank AND $FE

$C000-$FFFF: Fixed 16 KiB Inner PRG-ROM bank #7

• 2 (NROM-128)

$8000-$BFFF: Switchable 16 KiB Inner PRG-ROM bank

$C000-$FFFF: Mirror of $8000-$BFFF

• 3 (NROM-256)

$8000-$FFFF: Switchable 32 KiB Inner PRG-ROM bank (bit 0 of inner bank number ignored)

Notes

• The address ranges of the two banking registers do indeed partially overlap.
• Nestopia Plus! assigns this board to Mapper 281 instead.