Namco 175
| Company
|
Namco
|
| Games
|
4 in NesCartDB
|
| Complexity
|
ASIC
|
| Boards
|
110F0B
|
| PRG ROM capacity
|
512K
|
| PRG ROM window
|
8Kx3 + 8K fixed
|
| PRG RAM capacity
|
8K
|
| PRG RAM window
|
8K
|
| CHR capacity
|
256K
|
| CHR window
|
1Kx8
|
| Nametable mirroring
|
H or V fixed
|
| Bus conflicts
|
No
|
| IRQ
|
No
|
| Audio
|
No
|
| iNES mappers
|
210
|
Namco 340
| Company
|
Namco
|
| Games
|
8 in NesCartDB
|
| Complexity
|
ASIC
|
| Boards
|
CS000x
|
| PRG ROM capacity
|
512K
|
| PRG ROM window
|
8Kx3 + 8K fixed
|
| PRG RAM capacity
|
none
|
| PRG RAM window
|
none
|
| CHR capacity
|
256K
|
| CHR window
|
1Kx8
|
| Nametable mirroring
|
H, V, or 1 switchable
|
| Bus conflicts
|
No
|
| IRQ
|
No
|
| Audio
|
No
|
| iNES mappers
|
210
|
iNES Mapper 210 is used to denote Famicom boards bearing either the Namco 175 (Submapper 1) or Namco 340 (Submapper 2) ASIC. Both can be thought of as cost-reduced versions of the Namco 163:
| Function |
N163 |
N175 |
N340
|
| IRQ counter |
Yes |
No |
No
|
| ROM nametables |
Yes |
No |
No
|
| Optional WRAM |
Yes |
Yes |
No
|
| Expansion audio |
Yes |
No |
No
|
| ASIC-internal RAM |
Yes |
No |
No
|
| Mirroring |
Selectable (extended) |
Hard-wired H/V |
Selectable H/V/0
|
Game list
Namco 175 (Submapper 1)
| Name |
Battery |
WRAM |
Mirroring
|
| Chibi Maruko-chan: Uki Uki Shopping |
No |
No |
V
|
| Dream Master |
No |
No |
H
|
| Family Circuit '91 |
Yes |
2 KiB |
V
|
| Famista '91 |
No |
No |
V
|
| Heisei Tensai Bakabon |
No |
No |
V
|
Namco 340 (Submapper 2)
- Famista '92
- Famista '93
- Famista '94
- Splatterhouse: Wanpaku Graffiti
- Top Striker
- Wagyan Land 2
- Wagyan Land 3
Banks
- CPU $6000-$7FFF: 2 KB PRG RAM bank, mirrored four times (Namco 175 only)
- 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 175 and 340 have 12 registers within $8000-$FFFF. Each register occupies a range of $800 bytes, so $8000-$87FF all refers to one register, $8800-$8FFF all refers to another register, and so on.
CHR Select ($8000-$BFFF) w
| Value CPU writes |
Behavior
|
| $00-$FF |
Selects 1KB page of CHR-ROM
|
| Write to CPU address |
1KB CHR bank affected
|
| $8000-$87FF |
$0000-$03FF
|
| $8800-$8FFF |
$0400-$07FF
|
| $9000-$97FF |
$0800-$0BFF
|
| $9800-$9FFF |
$0C00-$0FFF
|
| $A000-$A7FF |
$1000-$13FF
|
| $A800-$AFFF |
$1400-$17FF
|
| $B000-$B7FF |
$1800-$1BFF
|
| $B800-$BFFF |
$1C00-$1FFF
|
External PRG RAM enable ($C000-$C7FF) w (Namco 175 only)
7 bit 0
---- ----
.... ...E
|
+- 1: Enable PRG RAM
PRG Select 1 ($E000-$E7FF) w
7 bit 0
---- ----
MMPP PPPP
|||| ||||
||++-++++- Select 8KB page of PRG-ROM at $8000
++-------- Namco 340 only: Select mirroring
0: One-screen A
1: Vertical
2: One-screen B
3: Horizontal
PRG Select 2 ($E800-$EFFF) w
7 bit 0
---- ----
..PP PPPP
|| ||||
++-++++- Select 8KB page of PRG-ROM at $A000
PRG Select 3 ($F000-$F7FF) w
7 bit 0
---- ----
..PP PPPP
|| ||||
++-++++- Select 8KB page of PRG-ROM at $C000
Notes
- Family Circuit '91 relies on its 2 KiB of WRAM being correctly mirrored throughout the $6000-$7FFF address range.
- Many INES Mapper 210 games are incorrectly set to INES Mapper 019.
- In the absence of a NES 2.0 header with submapper 1 or 2 to distinguish between Namco 175 and 340, the following heuristics have been suggested:
- If $E000.6 or $E000.7 are ever set, this should be a Namcot 340.
- If the game ever reads from or writes to PRG RAM, this is a Namco 175 with external RAM.
- If the game ever writes to $C000, this is probably a Namco 175.
See also
