Jamma Pinout
Parts Side Solder Side
GND A 1 GND
GND B 2 GND
+5V C 3 +5V
+5V D 4 +5V
-5V E 5 -5V
+12V F 6 +12V
key-key-key H 7 key-key-key
Coin Counter 1 J 8 Coin Counter 2
Coin Lockout 1 K 9 Coin Lockout 2
Speaker (-) L 10 Speaker (+)
Audio (note 1) M 11 (note 1) Audio
Red N 12 Green
Blue P 13 Sync
GND (video) R 14 Service
Test S 15 Slam
Coin 1 T 16 Coin 2
1-Start U 17 2-Start
1-Up V 18 2-Up
1-Down W 19 2-Down
1-Left X 20 2-Left
1-Right Y 21 2-Right
1-B1 Z 22 2-B1
1-B2 a 23 2-B2
1-B3 b 24 2-B3
  c 25  
  d 26  
GND e 27 GND
GND f 28 GND

Note 1:  Audio in some cases might be unamplified audio, or it might be the second speaker output with a stereo game.


Track ball interfacing:  The standard mentions the following mapping for trackball to joystick inputs. Note this has not been confirmed.
UpHorizontal Direction
DownHorizontal Clock
LeftVertical Direction
RightVertical Clock