Here are some Cyberball pinouts people might find useful.

Main board power:
  1 - Gnd
  2 - N/C
  3 - Gnd
  4 - 5V+
  5 - 5V+
  6 - 5V+

Joystick connectors (four):
  1 - Gnd
  2 - <Key>
  3 - Up
  4 - Down
  5 - Right
  6 - Left
  7 - N/C?
  8 - Start/Turbo/Throw
  9 - N/C?
  10 - N/C?
  11 - 5V+
  (Ground the switches to activate)

Audio board connector:
  This is just a direct cable between the audio board and the main board

JCoin connector (on audio board):
  1 - Gnd
  2 - <Key>
  3 - Right coin monitor 2
  4 - Left coin monitor 2
  5 - Right coin monitor 1
  6 - Left coin monitor 1

CNTL1 - Left stick, monitor 1
CNTL2 - Right stick, monitor 1
CNTL3 - Left stick, monitor 2
CNTL4 - Right stick, monitor 2

Video connectors:
  1 - Red
  2 - Gnd
  3 - <Key>
  4 - Green
  5 - Gnd
  6 - Blue
  7 - Gnd
  8 - Gnd
  9 - Negative composite sync
  10 - Positive V Sync
  11 - Positive H Sync