Galaga pinouts.  This also works on Midway's Mappy game

                               GALAGA/MAPPY

                        PARTS SIDE  |  SOLDER SIDE
                      LOGIC GND | A | 1 | LOGIC GND
                           SPKR | B | 2 | SPKR (Not sure of polarity)
                            --- | C | 3 | COIN METER
                            --- | D | 4 | ---
                                | E | 5 |
                            +5v | F | 6 | +5v
                      LOGIC GND | H | 7 | LOGIC GND
                      CREDIT SW | J | 8 | TEST SWITCH (Tilt connected to this)
 (2nd coin mech also) 1 COIN SW | K | 9 |
                       1P START | L | 10| 2P START
  (To rapid fire brd #7)   FIRE | M | 11|
                      MOVE LEFT | N | 12|
                                | P | 13|
                     MOVE RIGHT | R | 14|
                                | S | 15|
                            --- | T | 16| ---
                            --- | U | 17| ---
                            --- | V | 18| ---
                            --- | W | 19| ---
                                | X | 20|
                                | Y | 21|
                      LOGIC GND | Z | 22| LOGIC GND

On the CPU board there is an additional 3-part connector.  This is power.
It's wired as follows:

            1 - +12v
            2 - GND
            3 - +5v

On the Video board, there is an additional 6-part connector.  This is
the video connector.  It's wired as follows:

            1 - RED
            2 - GRN
            3 - BLU
            4 - SYNC
            5 - VIDEO GND
            6 - (Not used)