Unusual resolutions with Xorg VESA driver Mini-HowTo

These days ATI as well as NVidia are far too slow in adapting their Xorg drivers to new Chips as well as to new releases of Xorg, the Linux Kernel, and Distros. 
Therefore everyone who prefers e.g. working suspend/resume over GLX gimmicks, tends to go back to the VESA driver - which unfortunately tends to make it difficult to run "unusual" resolutions, especially for wide screens. (VESA ist still discussing which 16:9 and 16:10 resolutions they are going to declare official) 

So here are the steps that gave me 1920x1200 with VESA on my ThinkPad T61p:

  • Stop X, including this weird new failsafe thingie
  • Eventually uninstall any binary driver from NVidia or ATI
  • Use hwinfo --framebuffer to get a list of resolutions and color depths (!) your card's VESA interface claims to support. (No I do not know what to do if the wanted resolution is not availble)
  • Configure X to use VESA, e.g. with dpkg-reconfigure xserver-xorg. Do only use resolutions and color dephts just gained, and be reminded that the vesa driver does not really support other color depths than 8 (? not sure), 15, 16, 24; definitively not 32.
  • Use cvt width height freq (e.g. cvt 1920 1200 60) to generate ModeLine lines that you might want to put in the Monitor section of your xorg.conf (or in the Modes section if you want or have to use one)

This did it for me ;-)) 

From: IBCL BLog.
Originally posted: 2007-09-14