I am trying to run X at lower resolutions than 640x480. I have a diamond viper 770 video card. I found the modeline I need, it is:

Modeline "320x240@76i" 7.56 320 352 360 392 240 245 247 253
doublescan interlace

I inserted it at the end of the monitor section in XF86Config and then added "320x240@76i" to my mode list. Didn't work... I also tried it w/ Virtual-ie

"320x240@76i" Virtual 1600 1200

Still no luck...
Any ideas how to get this working? It would be really nice for playing xmame...

No linux gurus out there who know this??

well-
 

I'm not a guru by any stretch, but I did accidentally get XWindows (under KDE) running at 320x200 once. Slackware comes with a utiliy called XF86Setup. It's a graphical menu where you can set up XWindows. On the farthest tab to the right, you can pick any resolution from 320x200 to 2400x1600. This is how I did it- if you don't have XF86Setup (or don't have XFree86) I'm sure you can get it at ftp.slackware.com

FallingFrog

Well, kuber, have you tried to set your resolution within X by not hand editing the XF86Config. Usually it is a tricky task of editing the acutual file by hand, I have only done it once and successfully worked.
What distro are you using? most likely, if you run the xf86config utility, you can set it manually at what you want.