INES Mapper 185: Difference between revisions
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(Created page with "Category:iNES Mappers Here are Disch's original notes: ======================== = Mapper 185 = ======================== Example Games: -------------------------…") |
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[[Category:iNES Mappers]] | [[Category:iNES Mappers]] | ||
Here are Disch's original notes: | Here are Disch's original notes: | ||
======================== | |||
= Mapper 185 = | ======================== | ||
======================== | = Mapper 185 = | ||
======================== | |||
Example Games: | |||
-------------------------- | Example Games: | ||
Spy Vs. Spy (J) | -------------------------- | ||
Mighty Bomb Jack (J) | Spy Vs. Spy (J) | ||
Mighty Bomb Jack (J) | |||
Registers: | |||
--------------------------- | Registers: | ||
I'm unsure whether or not this mapper suffers from bus conflicts. I believe it does! Use extreme caution! | --------------------------- | ||
I'm unsure whether or not this mapper suffers from bus conflicts. I believe it does! Use extreme caution! | |||
$8000-FFFF: [CCCC CCCC] | |||
CHR Reg | |||
Notes: | |||
--------------------------- | Notes: | ||
This mapper is retarded. These games only have 8k of CHR, but they seem to attempt to disable CHR by writing | --------------------------- | ||
a specific value to the CHR Reg, then they VERIFY that garbage is read back, then they swap back to the | This mapper is retarded. These games only have 8k of CHR, but they seem to attempt to disable CHR by writing | ||
actual CHR. If they don't get the expected garbage, they lock up. | a specific value to the CHR Reg, then they VERIFY that garbage is read back, then they swap back to the | ||
actual CHR. If they don't get the expected garbage, they lock up. | |||
Perhaps this was some sort of copy protection? | |||
Perhaps this was some sort of copy protection? | |||
Each game has their own value that enables/disables CHR. Rather than failing to attempt to list all the | |||
exact values used here (I don't know what all of them are), I can provide some logic: | Each game has their own value that enables/disables CHR. Rather than failing to attempt to list all the | ||
exact values used here (I don't know what all of them are), I can provide some logic: | |||
if C AND $0F is nonzero, and if C does not equal $13: CHR is enabled | |||
otherwise CHR is disabled | if C AND $0F is nonzero, and if C does not equal $13: CHR is enabled | ||
otherwise CHR is disabled | |||
When CHR is disabled, it is as if CHR is filled with all $12's | |||
When CHR is disabled, it is as if CHR is filled with all $12's |
Revision as of 23:51, 13 November 2011
Here are Disch's original notes: ======================== = Mapper 185 = ======================== Example Games: -------------------------- Spy Vs. Spy (J) Mighty Bomb Jack (J) Registers: --------------------------- I'm unsure whether or not this mapper suffers from bus conflicts. I believe it does! Use extreme caution! $8000-FFFF: [CCCC CCCC] CHR Reg Notes: --------------------------- This mapper is retarded. These games only have 8k of CHR, but they seem to attempt to disable CHR by writing a specific value to the CHR Reg, then they VERIFY that garbage is read back, then they swap back to the actual CHR. If they don't get the expected garbage, they lock up. Perhaps this was some sort of copy protection? Each game has their own value that enables/disables CHR. Rather than failing to attempt to list all the exact values used here (I don't know what all of them are), I can provide some logic: if C AND $0F is nonzero, and if C does not equal $13: CHR is enabled otherwise CHR is disabled When CHR is disabled, it is as if CHR is filled with all $12's