Linux Tips: Dual-Head Display on Laptop

blblblbl

Spent sometime setting up dual monitor display with my laptop because couldn't find any info online. Here's some tips:

Sony K13; ATI 340M with 64MB shared VRAM.

1) Installed Fedora Core 3 (http://fedora.redhat.com/) on the 5G "back up" partition setup by Sony. The disk partitioner that comes with the CD doesn't work (there's a bug when the first partition of the harddisk is NTFS). I just used an old fdisk provided by Debian to do the job.

2) Setup GNOME.

3) Update the "system-config-display" package. (using yum, etc)

4) As root, go to system setting -> dual head -> use dual head. Now this won't do the job, but will save you some typing.

5) edit the /etc/X11/xorg.conf file by
a) in the "ServerLayout" section, add the lines
Screen 0 "Screen0" LeftOf "Screen1"
Screen 1 "Screen1" 0 0
Option "Xinerama" "on"
Option "Clone" "off"

(Xinerama is spanned display, Clone is dual X-server, either one will work)

b) In the 2 "Device" section, add the line
Option "MonitorLayout" "LVDS, CRT"

6) The bootloader tends to hang on dual-screen display, so you need to set the initial run-level to 3, edit the file /etc/inittab
change the line
id:5:initdefault:
to
id:3:initdefault:

7) reboot, log-on in the shell, and use "startx" to start your dual-screen display.

admin

+10

blblblbl

Wow that was quick. Thanks alot!

couple of notes:
-this setup should work for most dual-output cards.
- the line

Option "MonitorLayout" "LVDS, CRT"

is required in BOTH device sections because the X-server can't detect the 2 output ports by default. "LVDS, CRT" forces X to distinguish look for them.

I think this line is crucial if you want more monitors. For a PC you can have, say, 3 cards, each with 2 outputs, for 6 monitors. X's autodetection is good, but it doesn't always work. One should have an easier time to use this line to "force" detection and mapping of the screens.

- ATI also provides their own (proprietary) linux driver for free, which include 3D accelerations. However, the installation on is kinda painful (at least for mobile chips). It comes in RPM, but it doesn't install/uninstall "cleanly". I got stuck in the middle, and it didn't some invisible damage to the kernel and X.

blblblbl

Screen shot!