Apple Disk III

Background

The first variation of the Disk II introduced for the Apple III, called the Disk III (A3M0004), used the identical drive mechanism inside a modified plastic case with a proprietary connector. With some modification both drives are interchangeable. Though Apple sought to force the purchase of new drives with the Apple III, many former Apple II users quickly devised a way to adapt their existing and cheaper Disk II drives; however, only one external Disk II was supported in this manner. The Disk III was the first to allow daisy chaining of up to three additional drives to the single 26-pin ribbon cable connector on the Apple III, for a total of 4 floppy disk drives – the Apple III was the first Apple to contain a built-in drive mechanism. The Apple III Plus changed its 26-pin connector to a DB-25 connector, which required an adapter for use with the Disk III.