Set permanent custom resolution for Ubuntu and KDE Using Xrandr and Xsetup

KDE Logo

After switching from Gnome and Unity to KDE, I had a problem with SDDM and it was that it could not detect correct resolution for my UltraWide monitor and set it to Full HD instead of 2560×1080. I had a similar problem in Ubuntu with another old monitor. Anyway that solution is same in both cases.

The solution for this problem is using Xrandr and Xsetup to set the correct resolution and make it permanent.

For example, in my case for 2560×1080 resolution and 50hz refresh rate, I used the following commands:

xrandr --newmode "2560x1080_50.00" 188.75 2560 2712 2976 3392 1080 1083 1093 1114 -hsync +vsync
xrandr --addmode HDMI-2 2560x1080_50.00
xrandr -s 2560x1080 -r 50

Note: you can get the right numbers for the first line of command using this:

cvt 2560 1080 50

Ok, we have the correct commands and resolution for our system, but problem is that we should run all these commands after every reboot and also these commands won’t apply to our login screen, so we should use Xsetup file to run the commands before loading the desktop manager, so we put above commands into Xsetup file.

The path for Xsetup file in KDE 5 (Kubuntu 18.04):

/usr/share/sddm/scripts/Xsetup

And for older versions of KDE:

/etc/kde4/kdm/Xsetup
/etc/kde3/kdm/Xsetup
/etc/kde/kdm/Xsetup

Done, now reboot your system and enjoy the correct resolution.

Install Adobe AIR on 64-bit Ubuntu 10.10

Right now Adobe AIR is only officially available for 32-bit Linux. But it does work on 64-bit Linux with the 32-bit compatibility libraries. There are several ways to install Adobe AIR on Linux. My preferred way on Ubuntu is to use the .deb package. However the .deb package distributed by Adobe can only be installed on 32-bit systems. Good news is that this can be easily fixed! To install the Adobe AIR .deb package on a 64-bit system just follow these steps:

  1. Download the Adobe AIR .deb file
  2. In a terminal window go to the directory containing the adobeair.deb file
  3. Create a tmp dir:
    mkdir tmp

  4. Extract the deb file to the tmp dir:
    dpkg-deb -x adobeair.deb tmp

  5. Extract the control files:
    dpkg-deb --control adobeair.deb tmp/DEBIAN

  6. Change the Architecture parameter from “i386″ to “all”:
    sed -i "s/i386/all/" tmp/DEBIAN/control

  7. Repackage the deb file:
    dpkg -b tmp adobeair_64.deb

Now you can install Adobe AIR on a 64-bit system! From the command line just do:

sudo dpkg -i adobeair_64.deb

That’s it! Let me know if you have any questions.