[ppppenguin]

"A" is usually used to refer to the Ampex 5000 and 7000 series machines, not the IVC. These Ampex VTRs have the same drum size and video track layout as C format. The A and C machines all have alpha wrap. Many years ago I put a tape recorded on an Ampex 7003 on a C format machine. It sort-of worked. Since there are almost no working A format machines in existence it should be possible to modify a C format machine to play A format tapes.

The IVC 1" machines are very different. Omega wrap, smaller drum.

For completeness, B format was a Bosch 1" machine with segmented helical scan. Very good pictures but never really caught on because it couldn't do the "stunt" modes of the C format.