screen resolution and virtual desktop size

[Tomas Carnecky]

I have a 1280x1024 TFT monitor currently running in native resolution.
For games, I'd like to switch it to 1280x720 resolution, but so that the
picture doesn't stretch to the whole monitor, instead, I'd like to have
black bars on top and bottom of the monitor. The reason: games only let
me choose from available resolutions, and I'd like to play the game in
widescreen resolution. When I added a 1280x720 modeline to xorg.conf, it
didn't work quite like I wanted, the image was stretched vertically to
the whole monitor. And having a smaller virtual desktop size than the
monitor resolution didn't work. Is it possible to configure xorg the way
I want?

thanks
tom