INES Mapper 246: Difference between revisions
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(other caveat) |
(update according to Ice Man's findings) |
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[[Category:iNES Mappers|246]] | [[Category:iNES Mappers|246]] | ||
This is no longer Disch's original notes: | |||
======================== | ======================== | ||
= Mapper 246 = | = Mapper 246 = | ||
Line 14: | Line 14: | ||
-------------------------- | -------------------------- | ||
Regs lie at $6000- | Regs lie at $6000-601F; SRAM exists at $6800-6FFF. | ||
Line 23: | Line 20: | ||
--------------------------- | --------------------------- | ||
Range,Mask: $6000- | Range,Mask: $6000-601F, $6007 | ||
Line 50: | Line 47: | ||
Powerup/Reset: | Powerup/Reset: | ||
--------------------------- | --------------------------- | ||
$6003 set to $FF on powerup | $6003 set to $FF on powerup only | ||
The present hardware seems to be: | The present hardware seems to be: | ||
Line 58: | Line 55: | ||
* Miscellaneous resistors, diodes, and a battery to power the PRG RAM | * Miscellaneous resistors, diodes, and a battery to power the PRG RAM | ||
There is additionally some weird behavior on reads from $FFE4-$FFFF, but most existing dumps have been fixed to not need this. | |||
See also: | See also: | ||
* http://forums.nesdev.org/viewtopic.php?t=13969 Why does Fong Shen Bang only work in Famiclones? | * http://forums.nesdev.org/viewtopic.php?t=13969 Why does Fong Shen Bang only work in Famiclones? |
Revision as of 17:41, 29 March 2016
This is no longer Disch's original notes: ======================== = Mapper 246 = ======================== Example Game: -------------------------- Fong Shen Bang - Zhu Lu Zhi Zhan Notes: -------------------------- Regs lie at $6000-601F; SRAM exists at $6800-6FFF. Registers: --------------------------- Range,Mask: $6000-601F, $6007 $6000-6003: PRG Regs $6004-6007: CHR Regs CHR Setup: --------------------------- $0000 $0400 $0800 $0C00 $1000 $1400 $1800 $1C00 +---------------+---------------+---------------+---------------+ | $6004 | $6005 | $6006 | $6007 | +---------------+---------------+---------------+---------------+ PRG Setup: --------------------------- $8000 $A000 $C000 $E000 +-------+-------+-------+-------+ | $6000 | $6001 | $6002 | $6003 | +-------+-------+-------+-------+ Powerup/Reset: --------------------------- $6003 set to $FF on powerup only
The present hardware seems to be:
- Four 74LS670 4 x 4bit dual-ported memory
- One GAL16V8
- PRG ROM (up to 2 MiB), CHR ROM (up to 512 KiB), PRG RAM (8 KiB)
- Miscellaneous resistors, diodes, and a battery to power the PRG RAM
There is additionally some weird behavior on reads from $FFE4-$FFFF, but most existing dumps have been fixed to not need this.
See also:
- http://forums.nesdev.org/viewtopic.php?t=13969 Why does Fong Shen Bang only work in Famiclones?