First, to show the current setting and all the supported settings:
$ xrandrThis will display the allowed resolutions:
Screen 0: minimum 320 x 200, current 1024 x 768, maximum 4096 x 4096
VGA1 connected 800×600+0+0 (normal left inverted right x axis y axis) 267mm x 200mm
800×600 85.1* +
640×480 75.0 60.0
720×400 70.1
If you want to add a mode with resolution 1024X768, you can enter the following command:
$ cvt 1024 768
# 1024×768 59.92 Hz (CVT 0.79M3) hsync: 47.82 kHz; pclk: 63.50 MHz
Modeline “1024x768_60.00″ 63.50 1024 1072 1176 1328 768 771 775 798 -hsync +vsync
Now you need to create a modeline:
$ xrandr --newmode
Copy the modeline of the previous output to the place mode line:
$ xrandr --newmode “1024x768_60.00″ 63.50 1024 1072 1176 1328 768 771 775 798 -hsync +vsyncNow you need to add the above mode using the following command:
$ xrandr --addmode VGA1 1024x768_60.00here for VGA1 you have to use what ever that was there for $ xrandr output:
$ xrandr --output VGA1 --mode 1024x768_60.00Running these would change your resolution but this is temporary. Tthese steps were done to make sure that these commands work. Now we need to make these changes permanent.
Now you need to edit the default file:
$gksudo gedit /etc/gdm/Init/DefaultLook for the following lines:
PATH=/usr/bin:$PATH
OLD_IFS=$IFS
And add the the following lines below them:
xrandr --newmode “1024×768″ 70.00 1024 1072 1176 1328 768 771 775 798 -hsync +vsync
xrandr --addmode VGA1 1024x768_60.00
xrandr --output VGA1 --mode 1024×768
Save and exit the file.