Yes it's Supported!
Widescreen Support
WARNING: FOLLOWING METHOD DOES NOT WORK WITH ALL VERSIONS OF THE GAME (especially for 1920x1200 custom resolution).
Battlefield 1942 does not have native widescreen support. To use custom resolutions, navigate to Battlefield 1942\Mods\bf1942\Settings\Profiles\Custom and open the file Video.con in Wordpad. The following line is the one we are interested in:
game.setGameDisplayMode 1440 900 32 60
The first number is the width and the second is the height. Change these values to the resolution you want. In this example, the game would run at a resolution of 1440x900.
You can also adjust the game's field of view (FOV) so your screen takes advantage of the extra width. To adjust your FOV, navigate to Battlefield 1942\Mods\bf1942\Settings and open up VideoDefault.con. Find this line:
renderer.fieldOfView 1
This setting defaults to 1 for a standard 4:3 monitor. Change to suit your aspect ratio:
1.33333 for 16:9 1.25 for 15:9 1.2 for 16:10
To finish, make both files read only to prevent the game undoing your changes.
[edit] Supported Resolutions Resolution Supported 1280 x 800 (16:10) N 1440 x 900 (16:10) N 1680 x 1050 (16:10) N 1920 x 1200 (16:10) N 2560 x 1600 (16:10) N 1024 x 576 (16:9) - 1280 x 720 (16:9) - 1366 x 768 (16:9) N 1600 x 900 (16:9) N 1920 x 1080 (16:9) N
The game also does not seem to work with Eyefinity. Regardless of FOV settings, the entire game is stretched sideways, and the sky/ground is swapped.
🙂