
========================
=  Mapper 052          =
========================

Example Game:
--------------------------
Mario 7-in-1


Notes:
---------------------------

Yet another MMC3 multicart.  For info on MMC3, see mapper 004.


Registers:
---------------------------

  $6000-7FFF:  [.MHL SBPP]  Multicart reg
       P = PRG Block (bits 0,1)
       B = CHR+PRG Block Select bit (PRG bit 2, CHR bit 1)
       S = PRG Block size (0=512k   1=256k)
       L = CHR Block low bit (bit 0)
       H = CHR Block high bit (bit 2)
       M = CHR Block size (0=256k   1=128k)

  $8000-FFFF:  Same as MMC3 for selected block


$6000 can only be written to once ... and only if PRG-RAM is enabled and writable (see $A001).  Once $6000
has been written to, $6000-7FFF maps to PRG-RAM



PRG Setup:
---------------------------

   'S'    PRG-AND    PRG-OR
   ------------------------
    0       $1F    %BP0 0000
    1       $0F    %BPP 0000

 'B' and 'P' bits make a 3-bit value used as PRG-OR (left shift 4).  When 'S' is clear, the low bit of that
value is forced to 0.

PRG swapping behaves just like a normal MMC3 within this selected block


CHR Setup:
---------------------------

   'M'    CHR-AND    CHR-OR
   ------------------------
    0       $FF    %HB 0000 0000
    1       $7F    %HB L000 0000

 'H', 'B' and 'L' bits make a 3-bit value used as CHR-OR (left shift 7).  When 'M' is clear, the low bit of
that value is forced to 0.

CHR swapping behaves just like a normal MMC3 within this selected block


Powerup and Reset:
---------------------------

$6000 set to 0 on reset and powerup.
