Projectors on Ubuntu

[Paul Johnson]

On Mon, Jun 23, 2008 at 9:49 AM, Justin Tan <lord_king10 at hotmail.com> wrote:
> Hello,
>
> I am using Ubuntu 8.04, on a Thinkpad T61. I've been trying to get Ubuntu to
> work on a external projector but when I press Fn+F7 I do not see anything. I
> tried fiddling with it once but it ended up getting my computer stuck in
> 600x400 resolution and I had to reinstall ubuntu. Could anyone help me?
>
> Thanks in advance
>

If you have an Nvidia video card, and you are using the nvidia driver,
the Fn+F7 thing is not supposed to work.  Instead, there is a
configuration item called "TwinView" that manages it.  It is a
provision described in the Nvidia README file.

If you don't have Nvidia, I'd bet the advice the other guys give is
about right.  FIrst try to restart the laptop with the external video
connected and projector on.  While rebooting, go into system bios and
make sure the external video is not turned off. Sometimes it will be.

You can see if xrandr will work. If your video card is new enough and
if xrandr is enabled in the video driver, then it can "on the fly"
control the screen resolutions and control whether the presentation is
"cloned" or not.

First, I'd ask xrandr if it sees two devices:

# xrandr -q –verbose

When I do that on my laptop, it shows two devices.  One is called
DVI-0 and one is called VGA-0.  The first is the laptop's lcd, the
second is the projector. That's how I know it sees the projector.

I don't have the projector to test this, but the xrandr page says
"--same-as" is the option you need to get a clone display.  It will be
something like

# xrandr --output DVI-0 --mode 1280x1024 --output VGA-0 --mode
1024x768   --same-as DVI-0

The mode resolution settings are optional, AFAIK.  But I think it is
important to declare the 2 output devices by the same names that are
used in the xrandr output.

Oh, I just remembered I bookmarked a pretty good page about this:

http://andrearatto.homeunix.org/index.php/2008/external-projectors-or-monitors-with-gnulinux/

As I google, I find plenty of people with Intel laptops discussing xrandr.

http://yyhh.org/node/12


Suppose that does not work. In Ubuntu, there is a menu item System ->
administrator -> screen resolution.  There is an option in there to
control a second monitor.  See if it helps.

If that does not work, figure what kind of video card it is and see
their support for dual head monitors (You are trying for a "clone"
setup).  In ATI cards, the commands you would use to get two monitors
working is different for the different types of drivers.  The radeon
driver has a different approach than the fglrx driver.  One thing to
look for in your /etc/X11/xorg.conf file is a peculiar mode setting or
something that interferes with recognition of video modes.  In Nvidia
configurations, there are options like "NoEdidFreq" that will prevent
automatic recognition of new devices.

Sorry this is not easier. I've been through the school of hard knocks
on this, as you might guess.

-- 
Paul E. Johnson
Professor, Political Science
1541 Lilac Lane, Room 504
University of Kansas