

 +------------------------------+
 | 72-in-1 225 			  |
 +------------------------------+

 +---------------------------------------------+
 | The 72-in-1 pirate cart uses this mapper.   |
 +---------------------------------------------+

 +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
 |A15|A14|A13|A12|A11|A10|A09|A08|A07|A06|A05|A04|A03|A02|A01|A00|
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+  
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 | 1 | X | M | S | P | P | P | P | P | H | C | C | C | C | C | C |
 +---+---+-+-+-+-+-+-+---+---+---+-+-+-+-+-+-+---+---+---+---+-+-+
           |   |   |               |   |   |                   |
           |   |   +---------------+   |   +-------------------+
           |   |   |                   |   |
           |   |   |                   |   + Select 8K VROM bank at PPU
           |   |   |                   |      $0000
           |   |   |                   |
           |   |   |                   +---- Select upper half (1) or
           |   |   |                          lower half (0) of 32K PRG
           |   |   |                          page. This half is mirrored
           |   |   |                          both to $8000 and $C000.
           |   |   |                          No effect if page size is set
           |   |   |                          to 32K.
           |   |   |
           |   |   +------------------------ Select PRG page (size and
           |   |                              location determined by lines
           |   |                              A06 and A12)
           |   |
           |   +---------------------------- Select PRG page size. 0 - 32K,
           |                                  1 - 16K. If the size is 16K,
           |                                  it's mirrored at both $8000
           |                                  and $A000. Whether the top
           |                                  or bottom half of the 32K
           |                                  chunk is used depends on the
           |                                  condition of A06.
           |
           +-------------------------------- Mirroring select
                                              0 - Vertical mirroring
                                              1 - Horizontal mirroring

 Notes: - This mapper is interesting in that the address written,
           rather than the value, controls the switching. A15-A00 is
           simply the address written in binary notation. For example,
           writing to $A3C7 (1010001111000111 in binary) would select
           horizontal mirroring, 32K PRG bank #7, and 8K CHR bank
           #7. Note that only writes to $8000 and above are valid.
        - Vertical mirroring is probably set at powerup.
        - At reset, the first 32K ROM bank is swapped into $8000,
           and the first 8K VROM bank is swapped into PPU $0000.
        - Thanks to Mark Knibbs for hacking this mapper.

****************************************************************************

