X11 and using an external monitor (with a higher resolution)

kraileth · 2012-11-27 12:41:18

Hi everybody!

I've got a very old Laptop computer (it was running Windows 2000 it its days) and have successfully resurrected it with Linux. It became more or less a toy but right now I'm using it in a flat where I live half of the week and have no better computer. To make things a little more convenient I plugged in a real keyboard and mouse - and an external monitor.

Until recently the machine ran Trisquel (mini) but I've switched it to Arch now. With an older release of Trisquel everything display related worked fine. With the latest version my monitor displayed "out of reach" during the graphical loading screen but showed everything again once the login manager showed up. Now on Arch things do not really work anymore.

If I start the pc, the default configuration is that the laptop's display is turned off and just the external screen is used. That works fine on the console. But as soon as I run startx, the monitor goes "out of reach". If I switch modes (FN+F5 in my case) so that both the laptop's screen and the external monitor are on, there's no "out of reach" as I fire up X.

1) Does anybody have an idea what is the reason of that? I'd prefer to switch the laptop's own display off while using the external monitor. How would you do this on Arch?

2) And I have another question: If the laptop's display is turned off - is it possible to somehow set a higher resolution on the external monitor? 1024x768 (which is the laptop's limit) is not really much these days. Is there a way to achive this? X11's Multiple display support perhaps?

Trilby · 2012-11-27 12:55:55

`man xrandr`

kraileth · 2012-12-02 20:53:54

Hi, Trilby!

Thanks for pointing myself to the pretty obvious. However even after reading the man page multiple times I still have no idea how to do it. A little bit more precise a clue would really be helpful. If e.g. I use

# xrandr --current

this is the output:

xrandr: Failed to get size of gamma for output default
Screen 0: minimum 640 x 480, current 1024 x 768, maximum 1024 x 768
default connected 1024x768+0+0 0mm x 0mm
   1024x768         0.0*
   800x600          0.0
   640x480          0.0

Yes, that's all. If I use

# xrandr --auto

the output is only the first line of the previous. It doesn't detect any other monitor or anything.

So I still have no idea how to turn the laptop's display off nor do I know how to change the size of just the external monitor or even if that's possible at all.

Any ideas, anyone?

Trilby · 2012-12-02 21:06:32

According to that output, you only have one video output. What is the external monitor connected to?

Usually, where yours says "default connected .." xrandr would say "LVDS connected ..." or "LVDS1 connected ..." After that there would be another similar section for any other output such as VGA, or DVI. But xrandr is not detecting any other outputs on your machine. Have you created an xorg.conf? If so, do you define video outputs there?

You can set up all your video output in xorg.conf, but personally I find xrandr to be much easier. And if you've done something funny in xorg.conf, you'll restrict what xrandr can do later. In otherwords, if you have an xorg.conf, move or rename it, then rerun xrandr.

grd · 2012-12-05 14:46:15

#!/bin/bash
#set screen resolution

#echo $1 $2 $3

info=`cvt $2 $3 | grep Modeline`
info=${info:9:99}

`xrandr --newmode $info`
`xrandr --addmode $1 \"$2x$3_60.00\"`
`xrandr --output $1 --primary`

ssr VGA1 1440 900

that's what I do on my laptop + external monitor

mamamia88 · 2012-12-05 15:16:04

xrandr

lists your outputs

xrandr --output Laptop --off

xrandr --output Monitor --mode pixelsxpixels

kraileth · 2012-12-12 12:00:16

Thanks for trying to help, everybody!

For some reason it seems like this really old machine doesn't provide more than one output compatible with X. The rather strange thing is just that using the external monitor only and blacking out the laptop screen works well in text mode (and the monitor goes "out of reach" when I fire up X). I just did a little test if it was about drivers. So far I used the vesa driver and now installed the proper SIS one. This one provides more (lower) resolutions but xrandr doesn't detect any new outputs.

Using Windows, using just the external monitor works (Windows 2000 was installed on it when I bought it) and with Trisquel mini 5.0 (LXDE based) it worked, too. After an update to 5.5 the monitor would display text mode fine, go "out of reach" while displaying the splash screen and then work again once the graphical login manager is loaded. I guess that something changed with newer versions of X. But it's not really important since the laptop is almost 10 years old now and is more or less just a toy of mine. Except for this one thing it's working perfectly with Arch and I'm primarily using it to prove that even prehistoric hardware can still be put to use with Linux.

Trilby: No LVDS, no VGA, no nothing unfortunately. Hardware-wise the monitor is connected via a standard VGA plug, though. Xorg configuration was actually a good idea. I had to look for it since I didn't remember if I had been tinkering with it on that machine. But no, this system goes without xorg.conf.

It would be best to drop this issue now, I guess. I learned from it how it would work - so it actually wasn't in vain. But the ancient hardware is surely not worth any more time put into it.

grd: Thanks for that nice script! It's likely that I can put it to good use when I get my new laptop.

mamamia88: Yes, sounds reasonable. I'm pretty sure that would be it if X11 could make a difference between the laptop display and the external VGA adapter. I'll give it a try once I have another Linux laptop in my hands (except for this old thing I only have several desktop pcs). But it's good to know that things should work like that. So I wasn't wrong but just my hardware isn't compatible.

Arch Linux

#1 2012-11-27 12:41:18

X11 and using an external monitor (with a higher resolution)

#2 2012-11-27 12:55:55

Re: X11 and using an external monitor (with a higher resolution)

#3 2012-12-02 20:53:54

Re: X11 and using an external monitor (with a higher resolution)

#4 2012-12-02 21:06:32

Re: X11 and using an external monitor (with a higher resolution)

#5 2012-12-05 14:46:15

Re: X11 and using an external monitor (with a higher resolution)

#6 2012-12-05 15:16:04

Re: X11 and using an external monitor (with a higher resolution)

#7 2012-12-12 12:00:16

Re: X11 and using an external monitor (with a higher resolution)

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