INES Mapper 246: Difference between revisions
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[[Category:iNES Mappers|246]] | [[Category:iNES Mappers|246]] | ||
[[iNES Mapper 246]] seems to be a singleton for the Taiwanese game ''Fong Shen Bang - Zhu Lu Zhi Zhan''. | |||
It provides 2 KiB of RAM from $6800-$6FFF. | |||
Mask: $FFE7 | |||
$6000-6003: PRG Regs | |||
$6004-6007: CHR Regs | |||
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Powerup/Reset: | Powerup/Reset: | ||
--------------------------- | --------------------------- | ||
$6003 set to $FF on | $6003 set to $FF on cold boot. (All other registers probably also, but not required) | ||
The present hardware seems to be: | The present hardware seems to be: | ||
| Line 55: | Line 38: | ||
* 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, | There is additionally some weird behavior on reads from $FFE4-$FFFF: | ||
* PRG ROM access when A15..A5 AND A2 are all HIGH should instead occur from a bank where PRG A17 is high, i.e. ( [$6003] | $10 ) | |||
However, the existing dumps in GoodNES have been pre-patched to not require 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 01:48, 30 March 2016
iNES Mapper 246 seems to be a singleton for the Taiwanese game Fong Shen Bang - Zhu Lu Zhi Zhan.
It provides 2 KiB of RAM from $6800-$6FFF.
Mask: $FFE7
$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 cold boot. (All other registers probably also, but not required)
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:
- PRG ROM access when A15..A5 AND A2 are all HIGH should instead occur from a bank where PRG A17 is high, i.e. ( [$6003] | $10 )
However, the existing dumps in GoodNES have been pre-patched to not require this.
See also:
- http://forums.nesdev.org/viewtopic.php?t=13969 Why does Fong Shen Bang only work in Famiclones?
