INES Mapper 185

iNES Mapper 185 is used for games that use the CNROM board with weak copy protection measures.

 Here are Disch's original notes:
 
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 =  Mapper 185          =
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 Example Games:
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 Spy Vs. Spy (J)
 Mighty Bomb Jack (J)
 
 
 Registers: (**BUS CONFLICTS**)
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   $8000-FFFF:  [CCCC CCCC]
      CHR Reg
 
 
 Notes:
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 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