First, let me point out that the above image has been scanned in from a 16 year old 35mm slide and I have done the best possible job to try to retrieve the image in as high a quality as possible, however the slide has a great deal of minor scratches and other damage and this image was the best we could retrieve.
What you are viewing about is a slide taken of a prototype case design in July of 1983. It is believed, based on testimonials from 3 engineers that this may have been a suggested design case for the Atari 1600XL system. Although I cannot guarantee as of yet that this is 100% accurate, it seems likely that this case design as well as a similar case design may have been targeted for use in the Atari 1600XL and/or Atari Sierra 68000 Project.
Note the cartridge slot on the side of the unit as well as 2 joystick ports, this is in-line with the same layout as the Atari 1200XL, 1400XL and 1450XLD computers. On the front of the lower left of the case appears to be an indentation which may have been for an RJ11 type connector for a detachable keyboard.
Also notice the 2 disk drive ports do not appear to have levers to lower the drive heads and lock the diskette into the drive. Whether this is just an omission from the design as it appears to be an early prototype design for review or it is possible that the disk drives could've been self-ejecting 5.25" diskette drives.
The Atari Museum staff has spoken with Ajay Chopra, Joe Miller and Jay Titsler who all confirm that a dual-processor Atari system capable of running Atari 6502 code as well as Intel 80186 code had been built and in prototyping stages. The project was cancelled when James Morgan became CEO and turned Atari's focus back to its roots in videogaming and began to redirect engineering work into the Atari 7800 Prosystem as well as several other Atari videogame related projects.
Of further note: The ports and positions of these case designs seem to match the layout of an odd-ball prototype motherboard called the Atari 6402A. The board has all of the functionality of the 1450XLD with onboard disk controller. Perhaps there is some kind of connection between that board and these case designs. As of yet, no one from Atari's Home Computer Division has any information on this particular board.
Additional Files for project "Shakti"