For more information, see http://chad.glendenin.com/2008/09/21/sgi-o2-irix-video-modes/
See also: http://dart.ncsa.uiuc.edu/slevy/o2-stereo/
A long time ago, I had an SGI O2 workstation with an SGI 1600sw wide-screen flat-panel monitor. If I remember correctly, that's why I have a 1600x1024 video mode here, but I could be wrong... SGI probably natively supported its own monitor.
1400x1050 was a common resolution on flat-panel monitors at the time.
The o2-stereo.tar.gz file is a backup of the file on Levy's website (see above) in case it disappears for some reason.
mkvfo is a shell script I wrote over a decade ago, because I knew I wouldn't remember how to do this stuff. It looks like it takes three arguments: the horizontal resolution, the vertical resolution, and the refresh rate.
I don't remember what the 1600x1024_60.vfs.old file is for.