Atari had a 7800 port underway, outsourced to Imagitec Design, but abandoned it around 1992. (Ref.: http://www.atariprotos.com/7800/software/pitfighter/pitfighter.htm )
The DOS port of Pit-Fighter inexplicably uses a sprite resizing algorithm that stretches only vertically, not horizontally. This results in very odd-looking "skinny" fighters onscreen (as well as almost everything else).