Shugart 50-pin
The Shugart 50-pin interface was originally created by Shugart Associates for their eight-inch floppy drives, such as the Shugart SA800-2.
This interface was later borrowed by IBM and turned into the 34-pin PC Floppy interface. While a large number of pins and signals were dropped, the two interfaces are largely compatible and all that is needed to convert between the two is a passive adapter. For full bidirectional compatibility an active adapter is required, as the 8" drive needs a "boost" signal activated once the drive has gone beyond track 43. If this signal is missing, writing to the 8" media will become unreliable once writing goes beyond track 43.
The DBit FDADAP is one active adapter that can be used to connect Shugart 50-pin drives to a PC Floppy interface.