Linux & Devices

In this page

  1. Keyboard layout
  2. Disable touchpad edge scroll
  3. The cedilla affair
  4. Dual screen set up
  5. USB instal won't boot
  6. Install network printer Canon MX420

1. Keyboard layout

1.1. Add a alternative keyboard to the configuration:

  • Start menu > Settings > Settings Manager > Keyboard > Layout
  • Uncheck the 'Use system defaults' box
  • Click on the 'Add' button and add the alternative keyboard

1.2. Quick switch between keyboards:
1.2.1. Install xfce4-xkb-plugin: 

$ sudo apt-get install xfce4-xkb-plugin

1.2.2. Configure the plugin:

  • Right click on the 'Panel', i.e., the bar where open programs are show.
  • On the pop-up menu, select 'Panel > Add new items'
  • On the 'Search' box in the dialog box type 'keyboard'
  • Drag the 'Keyboard Layouts' entry to the 'Panel'. This will put a small flag on the panel.
  • Right-click on the flag and select 'Properties' to configure the applet (short cut for instance). In my case, I chose the combination 'ctrl-shift'
  • Go back to topic 1.1 and re-check the box 'Use system defaults'. This will make the system remember the shortcut. Otherwise it is forgotten at each logout/reboot.

2. Disable touchpad edge scroll

My hand keeps bumping on the left edge of the touch pad leading to undesired scrolling of the document. Scrolling can be disabled in the settings but this also disables two finger scrolling. To disable only the edge, reduce its are to zero.

  1. Start menu > Settings > Settings Manager > Session and Startup
  2. Tab Application Autostart: click Add.
  3. Enter the following
    • Name: synclient
    • Description: disable edge scrolling in mousepad
    • Command: synclient VertEdgeScroll=0
  4. Reboot.

3. The cedilla affair

For some reason the international English keyboard with dead keys sometimes (LibreOffice; TexMaker) produces the "ç" with the [ <alt-Gr>+, ] combination leaving the [ ' + c ] combination for the Ć character. I want "ç" for the latter. This is what I did. It doesn't work all the time.

  1. Backup and edit locale configuration file, found at:
    /usr/share/X11/locale/en_US.UTF-8/Compose
    Then search for "Ć" and replace by "ç", and search for "ć" and replace by "Ç".
  2. If that is not enough, some GTK applications might need:
    1. Backup and edit configuration file located in (important: in newer versions look for the file immodules.cache, probably in /usr/lib/i386-linux-gnu/gtk-xx/yyyy/)
      /usr/lib/gtk-2.0/2.10.0/gtk.immodules
      /usr/lib/x86_64-linux-gnu/gtk-2.0/2.10.0/gtk.immodules
      /usr/lib/i386-linux-gnu/gtk-2.0/2.10.0/gtk.immodules
    2. Search for line
      "Cedilla" "gtk20" "/usr/share/locale" "az:ca:co:fr:gv:oc:pt:sq:tr:wa"
      and add ":en" after "wa".
    3. Edit /etc/environement and add export GTK_IM_MODULE=cedilla
    4. Reboot.

4. Dual screen set up

  1. Assuming that both displays are detected, this is how I got them to show a contiguous desktop instead of two copies of the same.
    1. Go to 'Settings > Settings Editor' and chose 'displays'.
    2. Expand the 'Default' entry and you should see both displays.
    3. Expand the displays and expand the 'Position' entry.
    4. Set 'x' and/or 'y' values to place the displays.
  2. Both screens were not detected with my NVidia card (hdmi and dvi ports). This is what worked (although I am not fully happy with having to use the xorg.conf file):
    1. Install the latest NVidia driver (Start > Settings > Additional Drivers)
    2. Start > System > NVIDIA X Server Settings
    3. Click on 'X Server Display Configuration'
    4. Activate the screen; set the configuration as 'TwinView'; and whatnot.
    5. click on 'Save to X Configuration File'.
    6. Re-start the X server (shortcut is RightAlt+SysRq+k -- push the keys in this order).


5. USB instal won't boot

Sometimes, when installing xubuntu from a USB stick the system will not boot. The cause might be a problem with the way the disks were assigned, in particular when the usb stick is handled by the SCSI protocol. The stick may receive the /dev/sda name and the HD /dev/sdb. When the stick is removed the HD gets the /dev/sda spot and grub gets confused. The boot device is set to /dev/sdb which no longer exists. How to repair? Easy. Boot with a stick or a live CD or into the new installation with a stick inserted. 

$ sudo grub-install /dev/sda
$ sudo update-grub

Reboot without the stick in. This should work.

6. Install network printer Canon MX420

6.1. Printer side

  • Download Linux IJ Printer Driver MX420.tar from Canon website
  • Unpack and run install.sh (may need a chmod +x)
  • Follow the installation command line instructions

6.2. Scanner side

  • Download Linux IJ Scanner Driver MX420.tar from Canon website
  • Unpack and run install.sh (may need a chmod +x)
  • The command line to run the program is "scangearmp" but it is probably better to install a short cut for it in the start menu.