I recently hung an old iMac upsidedown from the ceiling to be used as a media center. It’s out of reach of the kids, but I needed to flip the video upside down. Since I am using Linux, I needed X11 to be inverted.
It ended up being really easy.
1) Generate an xorg.conf file:
sudo X -configure
(This is saved in ~/xorg.conf.new)
2) Copy the xorg.conf file to /etc/X11
sudo cp ~/xorg.conf.new /etc/X11
3) Restart X to make sure the conf file is good
sudo service kdm restart
(or sudo service lightdm restart, or whatever you’re using)
4) Edit /etc/X11/xorg.conf
Find the “Monitor” section and add this line:
Option "Rotate" "inverted"
5) Restart X11 again to apply the change. It should now appear upside-down
One shortcoming — If you have an built-in video camera, this does not flip the video camera upside down too. Since this is a media center, they won’t be needing the video camera at the moment.