Floppy disk

Floppy disks are a removable storage medium in which data is recorded onto a flexible magnetic surface. Apple has used many variants in its early history.

5&frac14;" disks
The original Disk II floppy drive for the Apple II series was based on a mechanism built by Shugart Associates with a controller designed by Steve Wozniak. This was succeeded by the Disk III for the Apple III which supported daisy chaining. Apple also created the DuoDisk to support two floppies with the Apple IIe and the Disk IIc, a compact mechanism for the Apple IIc. A UniDisk 5.25" was later produce to modernize the appearance of the drive for older Apple II models.

An Apple 5.25 Drive (A9M0107) supported 5&frac14;" floppies for the Apple IIe Card for the Macintosh LC.

FileWare disks
Apple developed its own 5&frac14;" format officially called FileWare, codenamed "Twiggy", after the 1960s fashion model. It was to have been introduced in the Apple III, but was not implemented until the release of the Apple Lisa. However, due to reliability problems with the drive, the Lisa 2 replaced the Twiggy mechanism with a smaller new 3&frac12;" format.

3&frac12;" disks
Steve Jobs wanted the the new Macintosh platform to support FileWare (a.k.a. "Twiggy") disks and had working prototypes built with such a drive. However, staff who were concerned about the poor reliability of the FileWare mechanism maintained contact with Sony, which had been developing the newer 3&frac12;" format. This drive ended up being implemented in the original Macintosh 128K in 1984. Apple also produced the a UniDisk 3.5" for the Apple II series.

The original 3&frac12;" disks were only read on one side and stored 400 KB. The Macintosh Plus and 512Ke supported double-sided 800 KB disks. The Macintosh IIx introduced the use of high density 1.4 MB disks which were alternatively referred to as SuperDrive and FDHD (Floppy Disk High Density). Apple began discontinuing the use of floppies and other legacy technologies with the first iMac G3 in 1988.