INES Mapper 072

 Here are Disch's original notes:  
 ========================
 =  Mapper 072          =
 ========================
 
 Example Games:
 --------------------------
 Pinball Quest (J)
 Moero!! Pro Tennis
 Moero!! Juudou Warriors
 
 
 Registers (**BUS CONFLICTS**):
 ---------------------------
 
   $8000-FFFF:  [MM.. PPPP]
     P = Page number
     M = Command
 
 
 Notes:
 ---------------------------
 
    Page numbers seem to pass through a latch.  Rather than writing to the regs directly, you write the
 desired page number and command to the latch, then send another command that copies the latch to the
 appropriate internal register.
 
    Commands:
      %00 = Copy latch to appropriate reg
      %01 = Set CHR Page
      %10 = Set PRG page
      %11 = Nothing/invalid
 
    Example:
      If a game wanted to select CHR page 3, it would first write $43, then $03.  Presumably, the $43 fills
 the latch, then the $03 looks at the latch, sees that it wants to set the CHR page, then copies the page
 number to the CHR reg (actually performing the swap).
 
    No idea if that's really how it works or not, but emulating it that way seems to work.
 
 
 CHR Setup:
 ---------------------------
 
       $0000   $0400   $0800   $0C00   $1000   $1400   $1800   $1C00 
     +---------------------------------------------------------------+
     |                            CHR Reg                            |
     +---------------------------------------------------------------+
 
 
 PRG Setup:
 ---------------------------
 
       $8000   $A000   $C000   $E000  
     +---------------+---------------+
     |    PRG Reg    |     { -1}     |
     +---------------+---------------+