The older AM models had the iISO/Auto-lock foot that preceded the Multi-Interface foot and shoe. Minolta introduced it in 1988 and Sony continued with it on some (but not all) of their cameras until 2012. Some cameras that used the auto-lock shoe were the α33, α55, α58, and NEX 7. Some people called it the "reversed" hotshoe.
Pictured below is a camera shoe with which the AM model flashes are compatible.

The newer M models have feet for the Sony Multi Interface Shoe (MI or MI S). Sony cameras since 2012 use this shoe.

There are adapters available from Sony that allow using flashes with one foot with cameras with the other shoe. Any automatic capability of the flash is maintained. ADP-MAA allows one to attach an iISO flash to a Multi Interface camera/shoe. ADP-AMA allows one to attach a Multi Interface flash to an iISO camera/shoe.