This page is graphics intensive. It may take a few moments to load. You know, I have never figured out why Atari had so many unreleased products. It boggles the mind to think about all of the great ideas that never made it out the door. Some say that Atari was ahead of it's time with some of these devices.
Many people feel that management was incompetent.
Whatever the reason, many products never made it off the drawing board. The XF351 model was a single sided drive, like the SF354 drive for the Atari ST computers. The XF351 and the SF354 drives looked identical, except for the connectors on the back. Both of these devices were never released. Dubbed the 1053, this unit also used a Tandon floppy drive mechanism like the 1050 drive.