Unless I'm very mistaken, Defcon shouldn't have been certified in the first place.
The MGL says Defcon is Hor+ while The_cranky_hermit said (in 2006) that it's anamorphic when zoomed out, Vert- when zoomed in... :?
Looks like plain old Vert- to me. The HUD scales correctly, but that doesn't make the game either anamorphic or Hor+ whatever the zoom level.
Besides, the game (v1.43) won't run fullscreen at any resolution. I can see Windows' taskbar in "fullscreen" 1680x1050, while only the left screen is active in all "fullscreen" TripleHead resolutions (and I can see my wallpaper & taskbar on the other two), so I can't see the menu or launch a game. (If this happens to you : close the game with Alt+F4 then edit preferences.txt in the game's install folder.)
So, I took the following shots while playing Defcon
windowed in Wide TripleHead. Please note that each individual bar in the HUD can be freely moved around (coordinates are saved in your preferences file), so don't mind them being all grouped on the left screen.
5040x1050, windowed, max zoom out
5040x1050, windowed, max zoom in, as far north as I could get (this is Tunisia = exact same limit as the max zoomed out view)
