P18: 44-pin edge connector (aux/small board)

        component side        solder side
        --------------        -----------
               +5V RTN  A  1  +5V RTN
                        B  2  +5V           
                        C  3  +22VDC
                        D  4
             AUDIO RTN  E  5  AUDIO +OUT
                        F  6  AUDIO -OUT
                        H  7  START LED
                        J  8
                        K  9
                        L 10
                        M 11
                        N 12  FIRE
                        P 13  START
                        R 14  LFT REVERSE
                        S 15  LFT FORWARD
                        T 16  RT REVERSE
                        U 17  RT FORWARD
                 RESET  V 18
                        W 19
                        X 20
               LED PWR  Y 21
                   GND  Z 22  GND


P20: 44-pin edge connector (main/large board)

        component side        solder side
        --------------        -----------
               +5V RTN  A  1  +5V RTN
               +5V REG  B  2  +5V REG
                        C  3  +22VDC
                        D  4  -22VDC
                COIN L  E  5
                COIN C  F  6  SLAM
                COIN R  H  7  TEST
           COIN CNTR R  J  8  COIN CNTR L
                        K  9  COIN CNTR C
                        L 10
                        M 11
                   GND  N 12  GND
                        P 13
                        R 14
                 Z OUT  S 15  Z GND
                 X OUT  T 16  X GND
                 Y GND  U 17  Y OUT
                 RESET  V 18
                        W 19  -5VDC
                        X 20  +12VDC
               +5V OUT  Y 21  +SENSE (+5V)
                   GND  Z 22  -SENSE (GND)