Using metamodes for proper letterboxing

Hello all,
This is a problem which has been bothering me for a while and so far I’ve had little success solving it. I enjoy playing older games, and my monitor is widescreen. Most older games, when run fullscreen, appear distorted. Under Windows it’s a simple matter to correct this (that is, to letterbox smaller resolutions with black bands on the sides) in the Nvidia settings panel, but no such option exists under nvidia-settings.

Doing some digging I was able to find this documentation, which seems to suggest that “metamodes” can be used to do this. However, the syntax confuses me. How can I center a game with, say, 1024x768 resolution, on my 1680x1040 desktop, without distortion?

The machine is running a GeForce GTX 650, 64-bit AMD CPU, and the OS is Debian.

Thanks for any suggestions!

uh…

Option “FlatPanelProperties” “Scaling = aspect-scaled”

under device section… And since when is this not in nvidia-settings?

http://i222.photobucket.com/albums/dd294/rm_shots/Computer/nvidia-settings.jpg

‘Aspect ratio scaled’

I’m not sure what version took the option away, but it’s definitely gone now. Here’s a forum thread about the issue, which specifically mentions that the option is gone: http://www.nvnews.net/vbulletin/showthread.php?t=184968 . It mentions the metamodes as well but in not enough detail to be helpful to me.

I have been experimenting with metamodes applied on the fly, though, such as this one:

nvidia-settings --assign CurrentMetaMode="CRT-0: 1680x1050 { ViewPortIn=1024x768, ViewPortOut=1400x1050+180+0 }"

which seems like it ought to be right but somehow it gets overwritten when I start a fullscreen game, and reverts to the same old distortion.