LinuxQuestions.org - Resolution problems with Slackware as VirtualBox guest

- Slackware (https://www.linuxquestions.org/questions/slackware-14/)

- - Resolution problems with Slackware as VirtualBox guest (https://www.linuxquestions.org/questions/slackware-14/resolution-problems-with-slackware-as-virtualbox-guest-662867/)

Resolution problems with Slackware as VirtualBox guest

Hi everyone,

I have some problems with the resolution on a slackware 12.1 install in VirtualBox (Windows XP host).

I have installed the guest additions and the mouse integration is working but the display is stuck at 1024x768. I have modified xorg.conf to include the additional resolutions but the machine boots to 1024x768 screen.

BUT, I can change to other resolutions that I have put into xorg.conf only through KDE control center. The machine goes back to 1024x768 at reboot. There is a checkbox to "keep these settings" but that is only effective if you use KDE, and I'm using fluxbox.

Another thing I have done is to only include the resolution I want to xorg.conf (1500x900) but it still boots to 1024x768. There are no references to 1500 or 900 in /var/log/Xorg.0.log or dmesg. It seems like it is not reading the xorg.conf! (but it is because the resolutions I entered come up in KDE control center)

Other things you might want to know: it is using the "vboxvideo" driver and I'm using xdm as the login manager.

Does anyone know what might be the problem?

Thanks in advance.

Often the video drivers do not support natively certain resolutions, so you must give the driver a "hint" in order it can send the monitor the correct lines.
Xorg comes with a little utility that can help you to determine what lines should the driver send to the monitor @ a defined frequency. The following is just an example

Code:

gtf 1440 900 60



  # 1440x900 @ 60.00 Hz (GTF) hsync: 55.92 kHz; pclk: 106.47 MHz

  Modeline "1440x900_60.00"  106.47  1440 1520 1672 1904  900 901 904 932  -HSync +Vsync

As you understand the above parameters are respectively HSync, VSync and refresh rate.
So now it is just a matter of putting the line

Code:

Modeline "1440x900_60.00" 106.47 1440 1520 1672 1904 900 901 904 932 -HSync +Vsync

in the section "Monitor" of your xorg.conf file. This way

Code:

Section "Monitor"

    Identifier  "ASUS P193W LCD"

    HorizSync  30-81

    VertRefresh 55-76

    Modeline "1440x900_60.00"  106.47  1440 1520 1672 1904  900 901 904 932  -HSync +Vsync

EndSection

The next step is you add the Modeline to the "Screen" section like this

Code:

Section "Screen"

    Identifier  "Screen 1"

    Device      "GeForce FX 5200 AGP"

    Monitor    "ASUS P193W LCD"

    DefaultDepth 24

        Subsection "Display"

        Depth      8

        Modes      "1440x900_60.00" "1024x768" "800x600" "640x480"

        ViewPort    0 0

    EndSubsection

    Subsection "Display"

        Depth      16

        Modes      "1440x900_60.00" "1024x768" "800x600" "640x480"

        ViewPort    0 0

    EndSubsection

    Subsection "Display"

        Depth      24

        Modes      "1440x900_60.00" "1024x768" "800x600" "640x480"

        ViewPort    0 0

    EndSubsection

EndSection

Check your Monitor manual first, of course
Hope this helps
Ciao

Hi urka58,

I tried your sugesstion but the problem still exists... Thanks for mentioning the gtf utility! It's handy!

I don't think that there is a problem with the monitor support because I can change to the wanted resolution through KDE control center. What puzzles me is that out of all the available resolutions (1440x900, 1024x768, 800x600) X chooses 1024x768 at startup. How do I say "start with 1440x900 please"?

That should work... can you post your /etc/X11/xorg.conf?
Ciao

Here is my xorg.conf. I have taken away all the comments so that it is more readable (they were only comments that come with default install of slackware).

Thank you for your help.

Code:

# **********************************************************************

# Module section -- this  section  is used to specify

# which dynamically loadable modules to load.

# **********************************************************************

#

Section "Module"



# This loads the DBE extension module.



    Load        "dbe"          # Double buffer extension



# This loads the miscellaneous extensions module, and disables

# initialisation of the XFree86-DGA extension within that module.

    SubSection  "extmod"

      Option    "omit xfree86-dga"  # don't initialise the DGA extension

    EndSubSection



# This loads the font modules

    Load        "type1"

    Load        "freetype"

    #Load        "speedo"



# This loads the GLX module

    Load      "glx"



EndSection



# **********************************************************************

# Files section.  This allows default font and rgb paths to be set

# **********************************************************************



Section "Files"



    RgbPath        "/usr/share/X11/rgb"



    FontPath  "/usr/share/fonts/local/"

    FontPath  "/usr/share/fonts/misc/"

    FontPath  "/usr/share/fonts/OTF/"

    FontPath  "/usr/share/fonts/TTF/"

    FontPath  "/usr/share/fonts/Type1/"

    FontPath  "/usr/share/fonts/CID/"

    FontPath  "/usr/share/fonts/Speedo/"

    FontPath  "/usr/share/fonts/75dpi/:unscaled"

    FontPath  "/usr/share/fonts/100dpi/:unscaled"

    FontPath  "/usr/share/fonts/75dpi/"

    FontPath  "/usr/share/fonts/100dpi/"

    FontPath  "/usr/share/fonts/cyrillic/"



# ModulePath can be used to set a search path for the X server modules.

# The default path is shown here.



#    ModulePath "/usr/lib/xorg/modules"



EndSection



# **********************************************************************

# Server flags section.

# **********************************************************************



Section "ServerFlags"





EndSection



# **********************************************************************

# Input devices

# **********************************************************************



# **********************************************************************

# Core keyboard's InputDevice section

# **********************************************************************



Section "InputDevice"



    Identifier        "Keyboard1"

    Driver        "kbd"





EndSection





# **********************************************************************

# Core Pointer's InputDevice section

# **********************************************************************



Section "InputDevice"



# Identifier and driver



    Identifier        "Mouse1"

    Driver      "vboxmouse"

    Option      "CorePointer"



    Option "Protocol"    "PS/2"



# The mouse device.  The device is normally set to /dev/mouse,

# which is usually a symbolic link to the real device.



    Option "Device"      "/dev/mouse"





EndSection





# **********************************************************************

# Monitor section

# **********************************************************************



# Any number of monitor sections may be present



Section "Monitor"



    Identifier  "My Monitor"

    HorizSync  31.5 - 50.0

    VertRefresh 40-90

    Modeline "1440x900_60.00"  106.47  1440 1520 1672 1904  900 901 904 932  -HSync +Vsync



EndSection





# **********************************************************************

# Graphics device section

# **********************************************************************



# Any number of graphics device sections may be present



Section "Device"

    Identifier  "VESA Framebuffer"

    Driver      "vboxvideo"

    #VideoRam    4096

    # Insert Clocks lines here if appropriate

EndSection



# **********************************************************************

# Screen sections

# **********************************************************************





Section "Screen"

    Identifier  "Screen 1"

    Device      "VESA Framebuffer"

    Monitor    "My Monitor"



# If your card can handle it, a higher default color depth (like 24 or 32)

# is highly recommended.



#  DefaultDepth 8

#  DefaultDepth 16

  DefaultDepth 24

#  DefaultDepth 32





    Subsection "Display"

        Depth      8

        Modes "1440x900_60.00" "1024x768" "800x600" "640x480"

    EndSubsection

    Subsection "Display"

        Depth      16

        Modes "1440x900_60.00" "1024x768" "800x600" "640x480"

    EndSubsection

    Subsection "Display"

        Depth      24

        Modes "1440x900_60.00" "1024x768" "800x600" "640x480"

    EndSubsection

    Subsection "Display"

        Depth      32

        Modes "1440x900_60.00" "1024x768" "800x600" "640x480"

    EndSubsection



EndSection



# **********************************************************************

# ServerLayout sections.

# **********************************************************************



Section "ServerLayout"



    Identifier  "Simple Layout"



    Screen "Screen 1"



    InputDevice "Mouse1" "CorePointer"

    InputDevice "Keyboard1" "CoreKeyboard"



EndSection

Hi Zoran, your /etc/X11/xorg.conf looks fine....so, have you tried starting the system on runlevel 3 (no xdm)?
Ciao

Yeah, runlevel 3 is running at 1024x768.

So no one knows why KDE (and only KDE) can change the resolution to 1440x900?