Namco 163

The Namco 106 and Namco 163 are ASIC mappers, assigned to iNES mapper 19. A variant of this mapper with hardwired mirroring is assigned to iNES mapper 210.

Overview

• PRG ROM size: Up to 512 KB
• PRG ROM bank size: 8 KB
• PRG RAM: Up to 8 KB
• CHR capacity: Up to 256 KB ROM and/or 32 KB RAM simultaneously
• CHR bank size: 1 KB
• Nametable mirroring: Controlled by mapper (Mapper 19), hardwired (Mapper 210)
• Subject to bus conflicts: No

Banks

• CPU $6000-$7FFF: 8 KB PRG RAM bank
• CPU $8000-$9FFF: 8 KB switchable PRG ROM bank
• CPU $A000-$BFFF: 8 KB switchable PRG ROM bank
• CPU $C000-$DFFF: 8 KB switchable PRG ROM bank
• CPU $E000-$FFFF: 8 KB PRG ROM bank, fixed to the last bank
• PPU $0000-$03FF: 1 KB switchable CHR bank
• PPU $0400-$07FF: 1 KB switchable CHR bank
• PPU $0800-$0BFF: 1 KB switchable CHR bank
• PPU $0C00-$0FFF: 1 KB switchable CHR bank
• PPU $1000-$13FF: 1 KB switchable CHR bank
• PPU $1400-$17FF: 1 KB switchable CHR bank
• PPU $1800-$1BFF: 1 KB switchable CHR bank
• PPU $1C00-$1FFF: 1 KB switchable CHR bank

Registers

The n106 has 19 registers within $4800-$FFFF, except $6000-$7FFF which is WRAM. Each register occupies a range of $800 bytes, so $4800-$4FFF all refers to one register, $5000-$57FF all refers to another register, and so on.

Sound Data Port ($4800-$4FFF) r/w

See Namco 163 audio.

IRQ Counter (low) ($5000-$57FF) r/w

7  bit  0
---- ----
IIII IIII
|||| ||||
++++-++++- Low 8 bits of IRQ counter

IRQ Counter (high) / IRQ Enable ($5800-$5FFF) r/w

7  bit  0
---- ----
EIII IIII
|||| ||||
|+++-++++- High 7 bits of IRQ counter
+--------- IRQ Enable: (0: disabled; 1: enabled)

CHR Select 1 ($8000-$87FF) w

7  bit  0
---- ----
CCCC CCCC
|||| ||||
++++-++++- Select 1KB page of CHR-ROM or CHR-RAM at $0000

Note: Pages $E0-$FF are CHR-RAM, as long as $E800.6 is set to 0. If $E800.6 is set to 1, then pages $E0-$FF refer to the last $20 pages of CHR-ROM as you'd expect.

CHR Select 2 ($8800-$88FF) w

7  bit  0
---- ----
CCCC CCCC
|||| ||||
++++-++++- Select 1KB page of CHR-ROM or CHR-RAM at $0400

Note: Pages $E0-$FF are CHR-RAM, as long as $E800.6 is set to 0. If $E800.6 is set to 1, then pages $E0-$FF refer to the last $20 pages of CHR-ROM as you'd expect.

CHR Select 3 ($9000-$97FF) w

7  bit  0
---- ----
CCCC CCCC
|||| ||||
++++-++++- Select 1KB page of CHR-ROM or CHR-RAM at $0800

Note: Pages $E0-$FF are CHR-RAM, as long as $E800.6 is set to 0. If $E800.6 is set to 1, then pages $E0-$FF refer to the last $20 pages of CHR-ROM as you'd expect.

CHR Select 4 ($9800-$9FFF) w

7  bit  0
---- ----
CCCC CCCC
|||| ||||
++++-++++- Select 1KB page of CHR-ROM or CHR-RAM at $0C00

Note: Pages $E0-$FF are CHR-RAM, as long as $E800.6 is set to 0. If $E800.6 is set to 1, then pages $E0-$FF refer to the last $20 pages of CHR-ROM as you'd expect.

CHR Select 5 ($A000-$A7FF) w

7  bit  0
---- ----
CCCC CCCC
|||| ||||
++++-++++- Select 1KB page of CHR-ROM or CHR-RAM at $1000

Note: Pages $E0-$FF are CHR-RAM, as long as $E800.7 is set to 0. If $E800.7 is set to 1, then pages $E0-$FF refer to the last $20 pages of CHR-ROM as you'd expect.

CHR Select 6 ($A800-$AFFF) w

7  bit  0
---- ----
CCCC CCCC
|||| ||||
++++-++++- Select 1KB page of CHR-ROM or CHR-RAM at $1400

Note: Pages $E0-$FF are CHR-RAM, as long as $E800.7 is set to 0. If $E800.7 is set to 1, then pages $E0-$FF refer to the last $20 pages of CHR-ROM as you'd expect.

CHR Select 7 ($B000-$B7FF) w

7  bit  0
---- ----
CCCC CCCC
|||| ||||
++++-++++- Select 1KB page of CHR-ROM or CHR-RAM at $1800

Note: Pages $E0-$FF are CHR-RAM, as long as $E800.7 is set to 0. If $E800.7 is set to 1, then pages $E0-$FF refer to the last $20 pages of CHR-ROM as you'd expect.

CHR Select 8 ($B800-$BFFF) w

7  bit  0
---- ----
CCCC CCCC
|||| ||||
++++-++++- Select 1KB page of CHR-ROM or CHR-RAM at $1C00

Note: Pages $E0-$FF are CHR-RAM, as long as $E800.7 is set to 0. If $E800.7 is set to 1, then pages $E0-$FF refer to the last $20 pages of CHR-ROM as you'd expect.

Nametable Select 1 ($C000-$C7FF) w

7  bit  0
---- ----
NNNN NNNN
|||| ||||
++++-++++- Select nametable at $2000:
             $00-$DF: Use a 1KB page of CHR-ROM as a nametable
             $E0-$FF: Use the NES's internal nametables (even values for A, odd values for B)

Note: On mapper 210, this register has no effect.

Nametable Select 2 ($C800-$CFFF) w

7  bit  0
---- ----
NNNN NNNN
|||| ||||
++++-++++- Select nametable at $2400:
             $00-$DF: Use a 1KB page of CHR-ROM as a nametable
             $E0-$FF: Use the NES's internal nametables (even values for A, odd values for B)

Note: On mapper 210, this register has no effect.

Nametable Select 3 ($D000-$D7FF) w

7  bit  0
---- ----
NNNN NNNN
|||| ||||
++++-++++- Select nametable at $2800:
             $00-$DF: Use a 1KB page of CHR-ROM as a nametable
             $E0-$FF: Use the NES's internal nametables (even values for A, odd values for B)

Note: On mapper 210, this register has no effect.

Nametable Select 4 ($D800-$DFFF) w

7  bit  0
---- ----
NNNN NNNN
|||| ||||
++++-++++- Select nametable at $2C00:
             $00-$DF: Use a 1KB page of CHR-ROM as a nametable
             $E0-$FF: Use the NES's internal nametables (even values for A, odd values for B)

Note: On mapper 210, this register has no effect.