TFROM: Difference between revisions
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m (Created page with ''''TFROM''' (NES-TFROM and HVC-TFROM) is a common board within the TxROM set. Like other TxROM boards, TFROM uses the Nintendo MMC3 ASIC. == Overview == * PRG ROM s...') |
(→Solder Pad Config: To do: determine which is which) |
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* Subject to [[bus conflict]]s: No | * Subject to [[bus conflict]]s: No | ||
== Solder | == Solder pad configuration == | ||
* Normal mode : 'CL1' connected, 'CL2' connected, 'H' disconnected, 'V' disconnected. | * Normal mode : 'CL1' connected, 'CL2' connected, 'H' disconnected, 'V' disconnected. | ||
* [[DEROM]] backward compatibility mode with Horizontal mirroring : 'CL1' disconnected, 'CL2' disconnected, 'H' disconnected, 'V' connected. | * [[DEROM]] backward compatibility mode with Horizontal mirroring : 'CL1' disconnected, 'CL2' disconnected, 'H' disconnected, 'V' connected. | ||
* | * DEROM backward compatibility mode with Vertical mirroring : 'CL1' disconnected, 'CL2' disconnected, 'H' connected, 'V' disconnected. | ||
Note : In DEROM backward compatibility mode, mirroring is hardwired and IRQs are disabled. However, the additional bank switching modes available by the MMC3 that weren't available with the MIMIC-1 chip used on DEROM boards are still present. | Note : In DEROM backward compatibility mode, mirroring is hardwired and IRQs are disabled. However, the additional bank switching modes available by the MMC3 that weren't available with the MIMIC-1 chip used on DEROM boards are still present. | ||
''To do:'' determine which of CL1 and CL2 affects the IRQ and which affects mirroring. | |||
== See also == | == See also == | ||
*[[MMC3|Nintendo MMC3]] | *[[MMC3|Nintendo MMC3]] | ||
Revision as of 14:52, 11 February 2010
TFROM (NES-TFROM and HVC-TFROM) is a common board within the TxROM set. Like other TxROM boards, TFROM uses the Nintendo MMC3 ASIC.
Overview
- PRG ROM size: 128, 256 or 512 KB (DIP-28/32 Nintendo pinout)
- PRG ROM bank size: 8 KB
- PRG RAM: None
- CHR capacity: 32 or 64 KB ROM (DIP-28 standard pinout)
- CHR bank size: 1 KB and 2 KB
- Nametable mirroring: Solder pads select horizontal, vertical or controlled by mapper.
- Subject to bus conflicts: No
Solder pad configuration
- Normal mode : 'CL1' connected, 'CL2' connected, 'H' disconnected, 'V' disconnected.
- DEROM backward compatibility mode with Horizontal mirroring : 'CL1' disconnected, 'CL2' disconnected, 'H' disconnected, 'V' connected.
- DEROM backward compatibility mode with Vertical mirroring : 'CL1' disconnected, 'CL2' disconnected, 'H' connected, 'V' disconnected.
Note : In DEROM backward compatibility mode, mirroring is hardwired and IRQs are disabled. However, the additional bank switching modes available by the MMC3 that weren't available with the MIMIC-1 chip used on DEROM boards are still present.
To do: determine which of CL1 and CL2 affects the IRQ and which affects mirroring.
