SPACE INVADERS

 18 PIN CONN            16 PIN CONN                 13 PIN CONN
    1 +5V                  1                           1  GND
    2 +5V                  2  COIN SW                  2  1 RIGHT
    3 +12V                 3  COIN SW                  3  1 LEFT
    4 +12V                 4  GND                      4
    5 -5V                  5  CTR                      5  KEY
    6                      6  RESET                    6  1 FIRE
    7                      7                           7  1 START
    8                      8  SP                       8  2 START
    9                      9  SP                       9
   10                     10  AUDIO VOLTAGE RETURN    10  2 FIRE
   11                     11  AUDIO VOLTAGE           11  2 LEFT
   12                     12  O-B TO MONITOR          12  2 RIGHT
   13                     13  GND                     13
   14 GND (- SENSE)       14
   15 GND                 15
   16                     16
   17 MONITOR
   18 MONITOR