intel driver and dual screen

[Kristian Høgsberg]

On Wed, 2008-01-16 at 09:14 -0500, Simo Sorce wrote:
> On Wed, 2008-01-16 at 12:52 +0100, Valent Turkovic wrote:
> > Hi,
> > when I connect external LCD monitor to my laptop's VGA connector I get
> > image on both monitors with the "same" resolution - just that the one
> > on the laptop is cropped.
> > Laptop supports 1280x800 and LCD 1280x1024 so I see the same desktop
> > on both screens just I don't see the bottom part on laptop screen.
> > 
> > I would like to have an option to do two things:
> > 1. to turn off the laptop screen when I'm using only the external one.
> > (I have vista on this laptop also but I don't use it - under vista I
> > can use FN+F4 to rotate video modes and in one video mode only
> > external LCD is on, under Fedora 8 FN+F4 does nothing)
> > 2. ability to switch both screens on but not in mirror mode but in
> > dual screen mode.
> > 
> > I'm using Fedora 8 with latest updates and with intel 2.1.1 driver.
> > 
> > Are there any intel utilities that make managing video setup easier?
> > Can you please point me to some web resources that address issues I
> > mentioned.
> > 
> > Thank you in advance,
> > Valent.
> 
> I have exactly the same situation, I have a xrandr command I start from
> my session that sets up the dual screen thing:
> 
> xrandr --output VGA --right-of LVDS

One things that's not very well documented is that you need to tweak you
xorg.conf for this to work.  You need to add a Virtual line to the
"Display" subsection in the "Screen" section of the xorg.conf file, for
example:

Section "Screen"
        Identifier "Screen0"
        Device     "Videocard0"
        DefaultDepth     24
        SubSection "Display"
                Viewport   0 0
                Depth     24
                Virtual   3600 1200
        EndSubSection
EndSection

The exact resolution depends on the monitors you want to use, but it has
to be big enough to hold both side by side.  In my case, I have
1900x1200 and 1680x1050 monitors side by side, which gives me the
numbers above.

cheers,
Kristian