desktop resize, how-to?

rover8898 · 12-06-2008, 04:42 PM

Hello all,

I feel really dumb for asking this:

How do I resize my desktop area in order for my entire desktop to fit on my 16:9 LCD monitor?
What I mean is how to I make my desktop not have unseen areas above and below the LCD that can only be seen by moving the mouse. It is very bothersome to me. I am used to windows where the entire desktop is resized to fit the entire screen size.

None of the different available resolutions I can choose from are 16:9 ratios. When I tried 1600:1200 (I think it was that, I know it was 16XX:XXXX), my screen went all screwy and I needed to plug my old CRT monitor to see a clear image and consequently be able to reset my screen resolution. Obviously my LCD monitor could not handle the new appointed resolution. The resolution that I am currently using is 1680x1050.

Post-scriptum:
I downloaded the linux driver for my ATI RADEON 9500 PRO video card, thinking it should resolve the issue. It installed sucessfully but when I tried running the ATI catalyst software, the computer complained about a library (I think it was something like GLIBC 2.?. ). Anyway, I de-installed the new driver after some head-scratching. I came to the conclusion that there must be something I am not doing right because, after all, 16:9 monitors have been common for several years now and as a consequence RHEL 5.1 should be equipped for an 16:9 screen.

distro: RHEL 5.1 (client)

Any help will be appreciated
-Roger

pixellany · 12-07-2008, 09:20 AM

Quote:

Originally Posted by rover8898

I feel really dumb for asking this:-Roger

Why?

It's always best to setup an LCD monitor to display its native resolution. What are the specs on your monitor?

To change the settings, the direct way is to edit /etc/X11/xorg.conf. You can do this by running "xorgconfig", but I prefer to do it by hand.

Here are the relevant settings for my machine: (non-relevant stuff removed)

Code:

Section "Monitor"
    Identifier  "My Monitor"
    HorizSync   31.5 - 79.0
    VertRefresh 50-70
EndSection

Section "Device"
    Identifier  "Mycard"
    Driver      "radeon"
EndSection

Section "Screen"
    Identifier  "Screen 1"
    Device      "Mycard"
    Monitor     "My Monitor"
    DefaultDepth 24

    Subsection "Display"
        Depth       24
        Modes       "1600x1200"
    EndSubsection
EndSection

This is for a 20" LCD and an older Radeon card. The "radeon" driver should also work for you and comes with just about any Linux distro.
Note: Whatever driver you install, you have to name it in xorg.conf.

If you plug in the right numbers for your monitor and it does not work, you will need to use a modeline. You can use "gtf" to make this. Here is an example for a 1600x900 display at 60Hz:

Code:

bash-3.2# gtf 1600 900 60

  # 1600x900 @ 60.00 Hz (GTF) hsync: 55.92 kHz; pclk: 119.00 MHz
  Modeline "1600x900_60.00"  119.00  1600 1696 1864 2128  900 901 904 932  -HSync +Vsync

To use this, plug it into xorg.conf like so:

Code:

Section "Monitor"
    Identifier  "My Monitor"
    HorizSync   31.5 - 79.0
    VertRefresh 50-70
    Modeline "1600x900_60.00"  119.00  1600 1696 1864 2128  900 901 904 932  -HSync +Vsync
EndSection

Section "Device"
    Identifier  "Mycard"
    Driver      "radeon"
EndSection

Section "Screen"
    Identifier  "Screen 1"
    Device      "Mycard"
    Monitor     "My Monitor"
    DefaultDepth 24

    Subsection "Display"
        Depth       24
        Modes       "1600x900_60.00"
    EndSubsection
EndSection

rover8898 · 12-07-2008, 10:42 AM

Hello,

Thank you for the reply.

Thank you for telling me about the gtf command. I am going to try it to see if I can make my screen be a slightly lower resolution than 1680x1050 because I find the text little too small for my taste. I solved my hidden top and bottom desktop area issue as is explained below.

This is my xorg.conf file (at least the monitor,device,screen sections of it)

Code:

-----------------------------------------------------------------------
Section "Monitor"

 ### Comment all HorizSync and VertSync values to use DDC:
 ### Comment all HorizSync and VertSync values to use DDC:
 ### Comment all HorizSync and VertSync values to use DDC:
 ### Comment all HorizSync and VertSync values to use DDC:
 ### Comment all HorizSync and VertSync values to use DDC:
 ### Comment all HorizSync and VertSync values to use DDC:
 ### Comment all HorizSync and VertSync values to use DDC:
 ### Comment all HorizSync and VertSync values to use DDC:
 ### Comment all HorizSync and VertSync values to use DDC:
 ### Comment all HorizSync and VertSync values to use DDC:
 ### Comment all HorizSync and VertSync values to use DDC:
 ### Comment all HorizSync and VertSync values to use DDC:
	Identifier   "Monitor0"
	ModelName    "Acer P211"
 ### Comment all HorizSync and VertSync values to use DDC:
	HorizSync    30.0 - 115.0
	VertRefresh  50.0 - 160.0
	Option	    "dpms"
EndSection

Section "Device"
	Identifier  "Videocard0"
	Driver      "radeon"
EndSection

Section "Screen"
	Identifier "Screen0"
	Device     "Videocard0"
	Monitor    "Monitor0"
	DefaultDepth     16
	SubSection "Display"
		Viewport   0 0
		Depth     24
		Modes    "1280x1024" "1024x768" "832x624" "800x600" "640x480" 
	EndSubSection
	SubSection "Display"
		Viewport   0 0
		Depth     16
	EndSubSection
EndSection
-----------------------------------------------------------------------

Don't know why there is so many times the same comment in the monitor section, but it may have to do with the fact that I tried to change the monitor type to several different models hoping that it would resolve my problem. But anyway it is just a comment, so it shouldn't matter (but I digress).

Anyways, my monitor is a ACER P201W 20" inch. The recommended video modes (according to their user's manual) are:
640x480
800x600
1024x768
1280x1024
1680x1050
1600x1200
832x624
(with various refresh rates)

Sidenote: The manual also stipulates that 1680x1050 is the max resolution, which is contradictory to the fact that 1600x1200 is also included. But this is a minor glitch.

Now oddly enough, even though the modes (listed in the screen section) in my xorg.conf file are "1280x1024" "1024x768" "832x624" "800x600" "640x480" and as such do not contain the 1680x1050 resolution, my desktop is functioning at the 1680x1050 resolution. It's been like that from right after installing RHEL linux. So i guess it was auto-detected as the preferred mode of operation of the LCD monitor.

Changing to some other resolution like 1280x1024 or 1024x768 placed the entire desktop in the screen (no hidden above or below areas). However as these resolutions are 4/3 or 5/4 ratios, the text was distorted and a pain to look at on 16:9 LCD screen.

However, I got the entire desktop to fit on the entire LCD screen (no hidden top or bottom areas) by doing the following
1. Moved the bottom panel on the top. So now I have 2 panels on the top of the screen.
2. Created a panel on the right side of the screen.

And for some reason, the desktop now fits the entirety of the screen
I am confused but content.

-Roger

tredegar · 12-07-2008, 11:55 AM

Re:

Quote:

### Comment all HorizSync and VertSync values to use DDC:
# HorizSync 30.0 - 115.0
# VertRefresh 50.0 - 160.0

X is getting quite clever nowadays. The above means that if you comment out the HorizSync and VertSync values as I have done in red then X will query your monitor and ask it what it is capable of, and then work out what modes can be supported and also work out what refresh rates need to be used.

Sometimes monitors lie about their capabilities though.

If you dislike untidiness, you can remove all of those comments. Something (harmlessly) buggy has put them in / not removed duplicates.

My current xorg.conf is a tenth the size it used to be (when it was also called something slightly different), because most of the configuration now happens "behind the scenes" at boot time, and X (usually) gets it right.
You can still go back to the old way, and define everything explicitly, in which case your entries in xorg.conf will take precedence over the automatic configuration.

Quote:

I am confused but content.

If you're content, we're happy.

pixellany · 12-07-2008, 05:06 PM

You say the max resolution is 1680x1050. That is also the native resolution (and is 16:10, not 16:9)

Regardless of whether you need a modeline, take out all the entries except for the max resolution.

I have never tried letting X figure out the right refresh settings, but I HAVE found that I have to restrict the vert refresh sometimes. In one case, I used 59.9-60.1 to force it to run at 60.