Atari

The 16/32-bit Atari  home computer platform was popular during the late 1980s and 90s, but it was widely considered that it was not possible to do a game like Doom on this platform due to technical restrictions of the standard machines.

Ports
Ports for the Atari Falcon include:
 * Doom (Atari Falcon) (1995-1998)
 * PmDoom (1998-2015)
 * Bad Mood (1995-Present)

Additionally, there was also "Doom Emulator Engine" which was released prior to the official source code release, which appeared to be based upon a leaked version of the Doom source code.

Performance
As with the Amiga ports, a high specification of Atari is required to run the ports which are largely based upon the official source code. This limits these to only working on Atari Clones such as the Hades, Milan and Medusa, or on highly accelerated Atari Falcon machines with upgrades such as the CT60/CT63.

Bad Mood has many optimizations tailored specifically to the Atari Falcon, and also has support for Atari specific hardware and so is able to run on much lower specification hardware. This however restricts it to only the Atari Falcon.

Tools
As part of the Bad Mood project, a native version of DEU was produced in 1995. GEM-DEU was ported from the original DOS version of DEU, however had a lot of Atari specific extensions to allow it to fully use the GEM windowing environment.

A native WAD tool called FalconWadTool was also built for the Atari Falcon to allow viewing and extracting / adding files to WADs.