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I have a DisplayLink USB-to-VGA adapter (17e9:0198 Newnham Research) I would like to add to my system (eventually two). I am running Linux 3.5.0-19-generic #30~precise1-Ubuntu SMP Wed Nov 14 21:43:28 UTC 2012 i686 i686 i386 GNU/Linux and Ubuntu 12.04.1 LTS.
I have an Asus G74Sx with the main screen and a second monitor on the VGA port. The DisplayLink-connected monitor shows green unless I hit CTRL-ALT-F1 in which case the other two monitors go blank and a login screen appears on the monitor connected to the DisplayLink. I can login and have a text-mode display.
What I really would like is to extend the desktop to the third monitor. Can anyone help?