Gefen DVI Detective N (EXT-DVI-EDIDN)
Computers can sometimes lose the EDID -- basically the electronic identification of a display which lists its possible resolutions and frequencies. When displays are switched away or disconnected and then reconnected, the EDID can be lost and the computer can lose the ability to display the image properly or at all.
The Gefen EXT-DVI-EDIDN is a DVI Detective which solves this problem by memorizing the EDID information. After a quick and simple EDID, simply connect the computer's video source to the DVI Detective, where it will fool the computer into thinking that a display is present, even when the port is inactive or the display is switched away to another computer.