INES Mapper 089

 Here are Disch's original notes:  
 ========================
 =  Mapper 089          =
 ========================
 
 Example Games:
 --------------------------
 Mito Koumon
 
 
 Notes:
 ---------------------------
 I do not know whether or not this mapper suffers from bus conflicts.  Use caution!
 
 
 Registers:
 --------------------------
   $8000-FFFF:  [CPPP MCCC]
     C = Select 8k CHR @ $0000
     P = Select 16k PRG @ $8000
     M = Mirroring:
       0 = 1ScA
       1 = 1ScB
 
 
 PRG Setup:
 --------------------------
 
       $8000   $A000   $C000   $E000  
     +---------------+---------------+
     |     $8000     |     { -1}     |
     +---------------+---------------+