Often I want to use an external display with my netbook, but I found with my eee if I use the hot key for changing the screen from LCD to external monitor there may be problems from displays not working to unexpected resolution changes.

Using xrandr things have worked much better. xrandr is a command line utility to change screen resolution on a single display or multiple displays. I can set the resolution for each display and even create an extended desktop.

EXAMPLE Commands

xrandr -q queries what displays are connected and possible resolutions.

xrandr --output LVDS --mode 1024x600 sets the LCD on the laptop to 1024x600

note: LVDS is the name for my eee's LCD you should use the name given when you run the xrandr -q command.

xrandr --output VGA --mode 1024x768 sets the external monitor connected to VGA port to 1024x768

note: VGA is the name for my eee's external vga port you should use the name given when you run the xrandr -q command.

Geek alert

The following tips are for the experienced user. These ideas could hose xorg use with care. You have been warned.

xrandr --output VGA --left-of LVDS
creates an extended desktop with the external monitor to the left of the lcd screen.

The extended desktop mode may require a change to your xorg.conf file. Remember xorg.conf has to edited by root. Always backup your xorg file before changing. You will need to restart xorg.conf for the changes to take effect.

Under the screen section I had to add the display subsection with the line
Virtual 2048 2048

Before


Section "Screen"
Identifier "Default Screen"
Monitor "Configured Monitor"
Device "Configured Video Device"
EndSection

After
Section "Screen"
Identifier "Default Screen"
Monitor "Configured Monitor"
Device "Configured Video Device"
SubSection "Display"
Virtual 2048 2048

EndSubSection
EndSection

xrandr is a great tool for configuring multi-head displays. For more information a good detailed article about xrandr is here http://www.thinkwiki.org/wiki/Xorg_RandR_1.2