An approach for using a data projector with X11 <draft>

The simplest approach to use a data projector with a laptop and a Unix-like operating system with X11 on top is to clone the display. This works out of the box with most laptops I've seen. Keep in mind that you often must boot the laptop with a connected data projector or that you have to use some magic keys to switch the external connector on.

In my setup I use a different approach. I've configured the xserver in such a way that it provides two screens: the data projector is connected to screen 0.1 and the internal display is connected to screen 0.0. Furthermore I have a script that starts a vncserver on a third display. One vncviewer is connected to the vncserver and shows up in fullscreen mode on screen 0.1, a second vncviewer shows up in a smaller window on screen 0.0. Now I can run my presentation software on the vncserver.

With this setup I can see my slides on the data projector and on my internal laptop display. So I can keep eye contact with my audience while talking and do not need to turn around to see the current slide. Furthermore I can display my notes etc. on the internal display.

So, you may ask how to configure your xserver to provide two screens? Unfortunately that is highly hardware dependent and often involves lots of fiddeling. As a starting point you can dowload my script (that script is no rocket science and may need some improvements) and the xorg.conf for my laptop (a R52 with a graphics chipset identified as ATI Radeon Mobility X300).