INES Mapper 057

 Based on Disch's original notes:  
 ========================
 =  Mapper 057          =
 ========================
 
 Example Games:
 --------------------------
 GK 47-in-1
 6-in-1 (SuperGK)
 
 
 Registers:
 ---------------------------
 
 Range,Mask:   $8000-FFFF, $8800
 
   $8000:  [CH.. ..AA]
      C = CHR Mode, 0=CNROM, 1=NROM
      H = CHR A16
      A = CHR A13-A14 in CNROM mode (only used if C=0)
 
   $8800:  [PPPO MBbb]
      P = PRG Reg
      O = PRG Mode
      M = Mirroring (0=Vert, 1=Horz)
      B = CHR A15
      b = CHR A13-14 in NROM mode (only used if C=1)
 
 
 CHR Setup:
 ---------------------------
 If C=0, the 8 KiB CHR-ROM bank is HBAA.
 If C=1, the 8 KiB CHR-ROM bank is HBbb.
 
 PRG Setup:
 ---------------------------
 
                $8000   $A000   $C000   $E000  
              +---------------+---------------+
 PRG Mode 0:  |     $8800     |     $8800     |
              +-------------------------------+
 PRG Mode 1:  |            <$8800>            |
              +-------------------------------+