multiple monitor configurations

[period3]

I'm running Intrepid on my thinkpad T60 laptop (ATI X1300, Radeon driver). I use two main configurations.

At work, I have a 1280x1024 external LCD, which I use in combination with the laptop's built in 1400x1050 LCD. To do this, I have added the following to the 'screen' section of xorg.conf:
SubSection "Display"
Virtual 2800 1050
EndSubSection

At home, I have a 1920x1200 external LCD. When I use it, I disable the laptop LCD. To use this configuration, I have to delete the above lines from xorg.conf, and logout and back in again.

How can I use both of these configurations without having to constantly change my xorg.conf?

(If I use the xorg.conf with the Virtual line, the resolution for my external monitor only goes as high as 1680x1050. If I use the xorg.conf without the virtual line, the dual screen setup doesn't work properly)

[period3]

Does anyone have any tips on this?

I'm running Intrepid on my thinkpad T60 laptop (ATI X1300, Radeon driver). I use two main configurations.

At work, I have a 1280x1024 external LCD, which I use in combination with the laptop's built in 1400x1050 LCD. To do this, I have added the following to the 'screen' section of xorg.conf:
SubSection "Display"
Virtual 2800 1050
EndSubSection

At home, I have a 1920x1200 external LCD. When I use it, I disable the laptop LCD. To use this configuration, I have to delete the above lines from xorg.conf, and logout and back in again.

How can I use both of these configurations without having to constantly change my xorg.conf?

(If I use the xorg.conf with the Virtual line, the resolution for my external monitor only goes as high as 1680x1050. If I use the xorg.conf without the virtual line, the dual screen setup doesn't work properly)

[skotos]

How can I use both of these configurations without having to constantly change my xorg.conf?

It is the problem I have asked for some info in a post of mine - see http://ubuntuforums.org/showthread.php?t=1081296 - but, just not to delete the configuration and simply "unrem" the profile you want to run, you might simply try something like this

Section "ServerLayout"
    Identifier     "LayoutOfLCDandElectron19BlueIII"
    Screen      0  "ScreenOf9815WKMI" 0 0
    Screen      1  "ScreenOfElectron19BlueIII" RightOf "ScreenOf9815WKMI"
EndSection

Section "ServerLayout"
    Identifier     "LayoutOfLCDandSonyTV"
    Screen      0  "ScreenOf9815WKMI" 0 600
    Screen      1  "ScreenOfSonyTV" Above "ScreenOf9815WKMI"
EndSection

Section "ServerFlags"
#    Option         "DefaultServerLayout" "LayoutOfLCDandElectron19BlueIII"
    Option         "DefaultServerLayout" "LayoutOfLCDandSonyTV"
    Option         "Xinerama" "0"
EndSection 

That is, store 2 layouts in the same xorg.conf and set the default server layout inside the ServerFlags section. This way you will not need to remember all the different parameters and sections, nor you will not duplicate any file.

If you want or need it, you may have a look at my full xorg.conf by going to the above mentioned post.

Unfortunately, I am running an Nvidia proprietary driver and I do not know how to check, just before running X, what kind of second device is present (or not), so at the moment I cannot write a shell script to automatically set the expected layout.

I think that this might be the real problem: is there any info under /proc on how many display devices and what hardware settings they are found to run with?

If this info were available just before X (eg. in the previous runlevel) a simple script - run as a service - might silently accomplish the task: see smani's suggestion.

HTH