Pinout for "I, Robot" CPU board connector (P20) A GND 1 GND Z GND 22 -Sense B +5V 2 +5V Y +5V out 21 +Sense 3 X Joystick X 4 Reset from switching power supply W E +10.3V unregulated 18 +10.3V unregulated C D F Led player 2 H Coin counter right J Joystick Y K L Coin right M Test N P R S T Fire 1 U Start player 2 V Reset out 5 6 Led player 1 7 Coin counter left 8 Audio 1 9 Audio 2 10 Coin left 11 Aux. coin 12 13 14 15 16 17 Start player 1 19 20 Pinout for "I, Robot" video board connector (P19) A Ground B +5V C D E F H Video ground J K L M N P R +5V S Ground 1 Ground 2 +5V 3 V sync 4 H sync 5 Red 6 Green 7 Blue 8 V int (interrupt?) 9 - Composite sync 10 11 12 13 14 15 Additional information: 10.3 V / 15.5 V ??? Looking at the power supply schematic, there is a 15.5V signal generated, that goes to pin E on connector P20. The voltage also goes to pin 9 on the 'control panel' connector (P24). However, if you look at the CPU pinout (above), pin E is mentioned as using 10.3V unregulated. I from what I see, I suppose that anything between 10.3V and 15.5V should work. I know many switching power supplies that you can buy come with +-12V output, maybe you can use this. Audio 1 / Audio 2 The CPU PCB has two audio outputs (pins 8 and 9) that connect to the switching power supply in the following way: CPU PCB Switching power supply Audio 1 (pin 8) - L audio (pin 1) Audio 2 (pin 9) - L audio GND (pin 2) The power supply has two additional outputs that connect to the speaker/volume control power supply L speaker + (pin 3) - 'utility panel' pin 2 L speaker - (pin 4) - 'utility panel' pin 1 speaker + I am not 100% sure where the Audio 1/2 signal is amplified. All I can tell is that the audio output from the CPU goes into the power supply, and two other audio lines go from the power supply to the volume knob / speakers. ----------------------------------------------------------------------- If it really was the truth, why are faces filled with anger that should only shine with youth? - Big Country ----------------------------------------------------------------------- John P. Manfreda Robert Bosch Corporation Applications/Software Engineer 38000 Hills Tech Drive (810) 553-1371 Farmington Hills, MI 48331-3417 -- jmanfred@fh.us.bosch.com or Frito@msn.com --