MMC2

The MMC2. Nintendo made this mapper specifically for one game- Mike Tyson's Punch Out. After Mike's big scandal, Nintendo renamed it simply to "Punch Out" and removed all references to Tyson.
As far as I know, this mapper was never used on any other game. The MMC4 is supposidly very similar, but with a slightly different banking setup. Unfortunately it was never used in any US carts, so I do not know what board prefix it uses.

Register description: to be finished


The Boards:

NES-PNROM - Max. 128K PRG, 128K CHR.
NES-PEEOROM - Max. 128K PRG, 128K CHR.



MMC2 Packaging Information



MMC2 comes in a 40 pin shrink-DIP package.



MMC2 Pinout:

                                  .----\/----.
                                  |          |
                            GND - |XX      XX| - +5V
                             M2 - |01      40| - +5V
                    PRG A14 (n) - |02      39| - GND
                    PRG A13 (n) - |03      38| - CIRAM A10 (n)
                    PRG A15 (r) - |04      37| - CHR A15 (r)
                    PRG A14 (r) - |05      36| - CHR A12 (r)
                    PRG A12 (s) - |06      35| - CHR A14 (r)
                    PRG A13 (r) - |07      34| - CHR A12 (n)
                    PRG A16 (r) - |08      33| - CHR A13 (r)
                    PRG /CE (r) - |09      32| - CHR A16 (r)
                     PRG D4 (s) - |10      31| - CHR A8 (s)
                     PRG D3 (s) - |11      30| - CHR A5 (s)
                     PRG D0 (s) - |12      29| - CHR A9 (s)
                     PRG D1 (s) - |13      28| - CHR A4 (s)
                     PRG D2 (s) - |14      27| - CHR A11 (s)
                    PRG R/W (n) - |15      26| - CHR A3 (s)
                    PRG /CE (n) - |16      25| - CHR A7 (s)
                    CHR /RD (s) - |17      24| - CHR A2 (s)
                     CHR A0 (s) - |18      23| - CHR A10 (s)
                     CHR A6 (s) - |19      22| - CHR A1 (s)
                            GND - |20      21| - CHR /CE (s)
                                  |          |
                                  `----------'

                                      MMC2


(note: the pins marked with 'X's are optional; they are only used if
the MMC2 were to be 42 pins instead of 40.)

(r) - this pin connects to the ROM chips only
(n) - this pin connects to the NES connector only
(s) - this pin is shared with the NES connector and ROM chips

The chip is marked either "MMC2" or "RD387-001". As far as is known, both are
the same device.


Registers:

8000h:
9000h:
------

Neither of these registers seem to be used.


A000h:
------

Select 8K PRG ROM page at 8000-9FFFh.


B000h:
------

Select a 4K CHR ROM page at 0000-0FFFh in PPU space when character 0FDh is read from 0000 to
0FFFh in PPU space.


C000h:
------

Select a 4K CHR ROM page at 0000-0FFFh in PPU space when character 0FEh is read from 0000 to
0FFFh in PPU space.


D000h:
------

Select a 4K CHR ROM page at 1000-1FFFh in PPU space when character 0FDh is read from 1000 to
1FFFh in PPU space.


E000h:
------

Select a 4K CHR ROM page at 1000-1FFFh in PPU space when character 0FEh is read from 1000 to
1FFFh in PPU space.


Characters 0FDh and 0FEh swap which banking register is used.  This was done to allow more
graphics to be placed on the screen simply by cueing the switchover point using a character.




F000h:
------

Mirroring:

7       0
---------
xxxxxxxxM


M:

0 - Vertical
1 - Horizontal




All HTML and graphics designed and copyright by Kevin Horton except chip package illustration.