VRC1
VRC1
| Company | Konami |
| Games | 6 in NesCartDB |
| Complexity | ASIC |
| Boards | JF-20, JF-22, 4036, 302114A, 350459 |
| Pinout | VRC1 pinout |
| PRG ROM capacity | 128K |
| PRG ROM window | 8K |
| PRG RAM capacity | none |
| PRG RAM window | n/a |
| CHR capacity | 128K |
| CHR window | 4K |
| Nametable arrangement | H or V, switchable |
| Bus conflicts | No |
| IRQ | No |
| Audio | No |
| iNES mappers | 075 |
The Konami VRC1 is an ASIC mapper. The iNES format assigns mapper 75 to VRC1.
The VRC1 was used in several Famicom games released by Konami and Jaleco:
- Exciting Boxing
- Ganbare Goemon! Karakuri Douchuu
- Jajamaru Ninpouchou
- King Kong 2: Ikari no Megaton Punch
- Moero!! Junior Basket: Two on Two
- Tetsuwan Atom
- CPU $8000-$9FFF: 8 KiB switchable PRG ROM bank
- CPU $A000-$BFFF: 8 KiB switchable PRG ROM bank
- CPU $C000-$DFFF: 8 KiB switchable PRG ROM bank
- CPU $E000-$FFFF: 8 KiB PRG ROM bank, fixed to the last bank
- PPU $0000-$0FFF: 4 KiB switchable CHR bank
- PPU $1000-$1FFF: 4 KiB switchable CHR bank
7 bit 0
---------
.... PPPP
||||
++++- Select 8 KB PRG ROM at $8000
7 bit 0
---------
.... PPPP
||||
++++- Select 8 KB PRG ROM at $A000
7 bit 0
---------
.... PPPP
||||
++++- Select 8 KB PRG ROM at $C000
7 bit 0
---------
.... .BAM
|||
||+- Mirroring (0: Vertical; 1: Horizontal)
|+-- High Bit of 4 KB CHR bank at PPU $0000
+--- High Bit of 4 KB CHR bank at PPU $1000
The mirroring bit is ignored if the cartridge is wired for 4-screen VRAM, as is typical for Vs. System games using the VRC1.
7 bit 0
---------
.... CCCC
||||
++++- Low 4 bits of 4 KB CHR bank at PPU $0000
These bits combined with bit 1 of $9000 make a 5-bit CHR selection.
7 bit 0
---------
.... CCCC
||||
++++- Low 4 bits of 4 KB CHR bank at PPU $1000
These bits combined with bit 2 of $9000 make a 5-bit CHR selection.