Atari XF551 information

The XF551 is a 5 1/4 inch floppy disk drive produced by Atari, Inc. for the Atari 8-bit computers. Introduced in 1987, it matches the gray design language of the XE models. It was the first drive from the company with official support for double-density and double-sided floppy disks—360 kB of storage per disk—and was also the final floppy disk drive Atari produced for the 8-bit computers. The XF551 allows faster transfer speed when used in double-density mode, doubling performance.

Although an XE-styled drive was shown several times during 1985 and 1986, production waited while leftover inventories of the Atari 1050 were sold off. By the time these ran out late in 1986, interest in the 8-bit line had waned and a new model was not put into production. At the same time, the success of the Nintendo Entertainment System (NES) prompted Atari to repackage their 65XE as the Atari XEGS video game console, boasting it could be expanded to a complete computer with the addition of a keyboard and disk drive. Nintendo sued, noting that Atari had no disk drives to sell, forcing Atari to rush the drive to market in June 1987 even though the software was not ready.

The XF551 is generally considered the best of Atari's drive offerings; not only does it store three times as much data as the 1050, it is twice as fast and almost silent in operation. Its release was marred by packaging it with an old version of Atari DOS which does not support the new features. This was addressed with DOS XE a year later. Support was dropped, along with the entire 8-bit computer line, in 1992.