How does the Imax film transport work?  I used to repair lots of
16-MM projectors in the eighties and I am fimilar with the geneva mechanism
you describe, at least the way it is on sixteen-s.

        Unless I am totally mixed up, the Imax film is 35-MM film but the
frames are shot length-wise so the whole system would look like a conventional
projector lying on its side.  I also seem to recall that the sound is digital
and recorded between the sproket holes.

Martin McCormick