There is a load of threads about xorg.conf editing, but none of them has really helped me.
I got my dual monitor system working somehow with the xorg.conf file below.
I use Jaunty and the above settings work just fine if I turn my laptop on so that the external monitor is attached. Then the dual monitor environment is enabled automatically (External monitor is extended by laptop to the right).
Identifier "Configured Monitor"
Identifier "Default Screen"
Monitor "Configured Monitor"
Device "Configured Video Device"
Virtual 2560 1024
Identifier "Configured Video Device"
Option "UseFBDev" "true"
Now the only problem is that even though I have given the virtual desktop 2560x1024 resolution, both of my screens are run on 1024x768 resolution. If I try to change resolutions (or anything else) from the Display Preferences the dual monitor environment gets turned off and my laptop will be the only display in use.
I would like to have my external (CRT) monitor on 1280x1024 and laptop on 1280x800 resolution. I'm having intel 915/910 chips in my laptop and the default driver. I have read that on intel chips larger virtual resolution than 2048x2048 needs 3d acceleration disabled. That's ok for me.
If there is somewhere a simple but still comprehensive guide to xorg settings, a link to it would be much appreciated also.