Created Friday 30 October 2020
Desired Resolution not listed
Start by listing the existing parameters detected for your monitors:
$ xrandr Screen 0: minimum 320 x 200, current 2944 x 1080, maximum 16384 x 16384 VGA-1 connected 1024x768+1920+0 (normal left inverted right x axis y axis) 521mm x 293mm 1280x1024 60.02 1440x900 59.89 1280x800 59.81 1280x720 60.00 1024x768 70.07 60.00* 800x600 72.19 60.32 56.25 640x480 72.81 66.67 59.94 HDMI-1 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 510mm x 287mm 1920x1080 60.00*+ 50.00 50.00 50.00 59.94 1920x1080i 60.00 50.00 59.94 1280x1024 60.02 1440x900 59.90 1280x800 59.91 1152x864 75.00 1280x720 60.00 50.00 59.94 1024x768 70.07 60.00 800x600 60.32 56.25
Generate the mode line for the desired resolution:
$ cvt 1920 1080 60 # 1920x1080 59.96 Hz (CVT 2.07M9) hsync: 67.16 kHz; pclk: 173.00 MHz Modeline "1920x1080_60.00" 173.00 1920 2048 2248 2576 1080 1083 1088 1120 -hsync +vsync
Add the modeline to the list of resolutions:
$ xrandr --newmode "1920x1080_60.00" 173.00 1920 2048 2248 2576 1080 1083 1088 1120 -hsync +vsync
Add the new mode to the monitor that needs it. In this example, use VGA-1:
$ xrandr --addmode VGA-1 1280x800
And finally, set the monitor to that resolution:
$ xrandr --output VGA-1 --mode 1280x800