This is the prototype schematic of the Atari 1053 disk drive.    The Atari 1053 would have looked exactly the same as the 1050 which the exception of its nameplate.   The drive would've been a full 360K disk drive that was backward compatible with the Atari 1050 and the 810 disk drives

        Several years ago the Atari Museum salvaged almost 20 internal Atari Engineering logbooks from Atari, Inc dating from 1981-1984.   Two log books mention the design of a new Atari 1053 double-sided/double density disk drive.   Also after a conversation with one of Atari's former Home Computer Division managers, it was also discovered that Atari engineers were using a "slush" fund of left over money from previous projects and were working on a side by side dual Atari 1050 unit with 2 Atari 1050's set-up into an XL styled case that looked very similar to an Apple ][ dual drive.   As of yet, the whereabouts of this in-house prototype are unknown.    As always, the Atari Museum is searching out of the far corners of the world in search of this and any and all other Atari projects.

        The Atari 1053 was among several proposed new disk drives Atari was looking into developing.   Also Atari was looking to severe ties with Tandon due to the poor reliability of its mechanisms, also it is noted from several notes from engineering meetings that Tandon was ignoring recommendations from Atari on fixes and updates to the 1050 drive line.      Atari was looking at Sanyo, Sony, Hitachi, Seagate and several other companies for 5.25", 3.5" and even 3" drive mechanisms.   Several new drives were proposed including:
 

The Atari 1053 Double Sided/Double Density Drive Drive
The Atari 1055 3.5" disk drive (prototypes exist of these units, the case design was done by Tom Palecki)
The Atari 1056 Disk Drive
The Atari 1057 Syquest 3.9" removable disk drive
The Atari 1058 Very Low Cost Disk Drive

(Actually Engineering notes and meeting notes to follow)