If you are looking at the cable end, not the camera end, here is the pinout on a 3 prong Nikonos cable.
There is an indention in the part that goes into the camera; hold that indention to the 6 o'clock position.
Mentally number the pins from left to right as 1,2,3. Pin 2 will be opposite the indention.
Pin 1 = M sync
Pin 2 = Ground Directly across from the indention.
Pin 3 = X sync
M sync is for flashbulbs, so you will be shorting ground to X-sync pin to make the strobe fire.
Best of luck,