[ltp] Clone display via VGA output on Thinkpad T41p, Radeon M10 (FireGL T2), Xorg 7.3

[Alex Deucher]

On 10/24/07, Andreas Ntaflos <daff@dword.org> wrote:
> Hello list,
>
> I have a Thinkpad T41p with a Radeon M10 (FireGL T2) using the open source
> Radeon drivers with Alex Deuchers patches [1] from git, running Kubuntu 7.10
> with Xorg 7.3.
>
> What I need to know is how to set up a xrandr to clone the LVDS screen to the
> VGA port? The typical scenario for this is connecting a beamer to the VGA
> port, for example when doing a presentation or a lecture, so that the same
> picture is displayed on the laptop screen and the beamer canvas. The beamer
> typically only supports resolutions up to 1024x768.
>
> In the olden days I had to switch between
>
> Option          "CRT2Position"          "Clone"
>
> and
>
> Option          "CRT2Position"          "RightOf"
>
> in xorg.conf (and restart the X server), depending on what I wanted.
>
> How is this done with the new Xorg 7.3 and xrandr 1.2? How do I get the same
> picture on both the LVDS and the VGA output?
>
> I have read the ThinkWiki article [2] googled much and found out about the bug
> where the second screen is positioned /inside/ the first (primary) screen. I
> suffered from that, too, when trying to set up the lecture I had to give a
> week ago.
>
> So my questions is: how do I clone the LVDS display these days? Is it
> possible? How to do it? I can provide further configuration details if
> necessary but more I'd like to know the standard way to configure this setup.

xrandr --help
should answer all of you questions.

turning on an output will automatically bring it up in clone mode, so:
xrandr --output VGA-0 --auto
should bring up the VGA port as a clone of LVDS assuming it's
connected.  If it's not connected and you want to force it on anyway:
xrandr --output VGA-0 --mode 1024x768 (or whatever mode you want).
to turn it off:
xrandr --output VGA-0 --off
to add new modes take a look at xrandr --newmode and xrandr --addmode
for dualhead, take a look at --right-of, --left-of, --pos, etc.

Alex