INES Mapper 057

 Here are Disch's original notes:  
 ========================
 =  Mapper 057          =
 ========================
 
 Example Games:
 --------------------------
 GK 47-in-1
 6-in-1 (SuperGK)
 
 
 Registers:
 ---------------------------
 
 Range,Mask:   $8000-FFFF, $8800
 
   $8000:  [.H.. .AAA]
      H = High bit of CHR reg (bit 4)
      A = Low 3 bits of CHR Reg (OR with 'B' bits)
 
   $8800:  [PPPO MBBB]
      P = PRG Reg
      O = PRG Mode
      M = Mirroring (0=Vert, 1=Horz)
      B = Low 3 bits of CHR Reg (OR with 'A' bits)
 
 
 CHR Setup:
 ---------------------------
 'A' and 'B' bits combine with an OR to get the low 3 bits of the desired page, and the 'H' bit is the high
 bit.  This 4-bit value selects an 8k page @ $0000
 
 
 PRG Setup:
 ---------------------------
 
                $8000   $A000   $C000   $E000  
              +---------------+---------------+
 PRG Mode 0:  |     $8800     |     $8800     |
              +-------------------------------+
 PRG Mode 1:  |            <$8800>            |
              +-------------------------------+