In article , AUE@phys.rug.nl says...

>does anybody know the layout of the F3 TTL flash contacts ??
>I'd like to make an extension cord, but of a different design compared
>to the one Nikon makes. I'd like to incorporate the PC connector on
>the front of the camera, so the cable doesn't block the film rewind
>thing. But then I have to know what the function of the contacts is.

The AS-7 shoe does this nicely, and provides a separate ASA ring for
setting TTL fill ratios - and provides an extra ISO (non-TTL) hot-shoe.
All that in one expensive little shoe adapter! (Kinda wish I hadn't
sold mine.....)
Hope This Helps