Force screen resolution

Some VGA cables and KVM switches do not support DCC, preventing the display from reporting the supported screen resolutions. The result is that you are unable to select 1280x1024. Instead you get stuck with 1024x768, for example.

The solution is to search on the internet for the correct modeline for the resolution you want. Then create /etc/X11/xorg.conf with the following content:

Section "Device"
        Identifier      "Configured Video Device"
EndSection

Section "Monitor"
        Identifier      "Configured Monitor"
        ModeLine "1280x1024" 108.0   1280 1328 1440 1688 1024 1025 1028 1066 +hsync +vsync
EndSection

Section "Screen"
        Identifier      "Default Screen"
        Monitor         "Configured Monitor"
        Device          "Configured Video Device"
        DefaultDepth 24
        SubSection "Display"
                Depth 24
                Modes "1280x1024" "1024x768"
        EndSubSection
EndSection

Next time you boot, you will be able to select 1280x1024.