WB is at 1024x768 , the screenmodes are in CGX.
For example - When I open ADoom I can select , say 800x600, and it opens at that resolution. It's just fills about a quater of the screen though.
I think that ADoom is opening with a screen size (not screen mode) of 320x200. I think you can change the size from with in the tool types I know at least one version let you set it up this way (read the docs).
Also like Lionstorm said you should set up some other modes from within CGX prefs because some of the games will need 320x200 320x240, 640x480 etc and also ADoom might not run as smoothly as it could at 800x600.
