Namco system 246 pinout

Hey everybody, I've just purchased a system 246, but it didn't come with the power lead for the I/O board to the mother board. Does anybody have the pin out for the motherboard it's self? Specificially the 6 pins at front. Thanks for your help!

Dont know much about the system, isnt it standard GND, 5 and 12 volts for the audio amp. Should be easy to determine that at the mobo ?