Hi, i would patch xorg in such way that i can modify the pixmap for security reasons (Soft tempest). The first, idiot, goal is to send to the monitor a function of the "normal" pixmap (more precisely the negative of the color). I would try just to flip each bit into the framebuffer automatically but i can't find where the server sends data to the video card on each refresh. I'm still understanding how all the things works in xorg so any suggestions would be much appreciated. Thank you Antonio