xrandr set resolution

If you have too low resolution and you want to make a higher resolution, you can use xrandr. Examples:

Computer reqognizes 1024×800 resolution when running xradr command.
To test and set new resolutions:

cvt 1280 1024

… the output
# 1280×1024 59.89 Hz (CVT 1.31M4) hsync: 63.67 kHz; pclk: 109.00 MHz
Modeline ”1280x1024_60.00” 109.00 1280 1368 1496 1712 1024 1027 1034 1063 -hsync +vsync

…. to make a new resolution
xrandr –newmode ”1280x1024_60.00” 109.00 1280 1368 1496 1712 1024 1027 1034 1063 -hsync +vsync

xrandr –addmode VGA1 1280x1024_60.00

… to test the resolution open Displays or run a command
xrandr -s 1280×1024

Example 2:

cvt 1366 768

… the output
# 1368×768 59.88 Hz (CVT) hsync: 47.79 kHz; pclk: 85.25 MHz
Modeline ”1368x768_60.00” 85.25 1368 1440 1576 1784 768 771 781 798 -hsync +vsync

…. to make a new resolution
xrandr –newmode ”1368x768_60.00” 85.25 1368 1440 1576 1784 768 771 781 798 -hsync +vsync

xrandr –addmode VGA1 1368x768_60.00

… to test the resolution open Displays or run a command
xrandr -s 1368×768

NOTICE THAT

xrandr can make so big resolution that you get a black resolution or some old display can literally explode, because it has no self-protection. If you get the black screen, press Ctrl F2 and Ctrl Alt Del for rebooting the computer.

TO SET THE RESOLUTION PERMANENT

Read the next article
https://wiki.ubuntu.com/X/Config/Resolution#Setting_xrandr_changes_persistently

If you can´t find the proper resolution, old Knoppix, Mepis and antiX can make a good /etc/X11/xorg.conf file, which can be copied to an problematic system.

wonder knoppix.xorg.conf