Add higher resolution modes to a monitor whose EDID is not properly processedUse
cvt <horizontal pixels> <space> <vertical pixels> <space> <vertical refresh frequency> to obtain the mode numbers in a terminal. For example, on mine:
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cws@cws-desktop:~$ cvt 1280 1024 60
# 1280x1024 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
cws@cws-desktop:~$
You should always perform all steps before entering in a script, so the next line in the script using
xrandr from the
x11-xserver-utils package would be to use
xrandr to find out what your display is designated. Your display may go to a blank black display temporarily every time you use
xrandr. On my system, the output looks like:
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cws@cws-desktop:~$ xrandr
Screen 0: minimum 320 x 200, current 1280 x 1024, maximum 4096 x 4096
VGA-1 connected 1280x1024+0+0 (normal left inverted right x axis y axis) 0mm x 0mm
1024x768 60.0
800x600 60.3 56.2
848x480 60.0
640x480 59.9
1280x1024 59.9*
cws@cws-desktop:~$
Except during boot on a fresh system the last line does not exist. The first line after the input
xrandr command may say that the system cannot get the gamma of the display. If this shows up, you probably can't use this method to add a higher resolution mode. If you don't have the error about not reading gamma, the first line will tell you what the machine you are using says that the display card thinks about your display. The Screen 0 (or 1 or 2) considers the physical connection to your display from the connectors (or internal connections) to your display card. The next line, which in my case reads VGA-1 is the code for the display and tells you something about whether you have a 15 pin VGA connector, an HDMI connection, a DVI connection, or an internal display for a laptop. The display name of the display which you want to modify comes from this area.
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xrandr --newmode 1280x1024 109.00 1280 1368 1496 1712 1024 1027 1034 1063 -hsync +vsync
The new mode name (in this case 1280x1024) should be descriptive of the mode, but if you simply copy the mode line from
cvt, or it has an @ or _ symbol or other non alphanumeric character ( a space?), must be surrounded by quote marks. If you simply have numbers surrounding an x, you don't need quote marks. The numbers are copied from the Modeline line from the
cvt command output.
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xrandr --addmode VGA-1 1280x1024
The next line adds the new mode to your mode listing in
xrandr or your Resolution pull-down list from your Menu >> Settings >> Display menu entry.
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xrandr --output VGA-1 --mode 1280x1024
Finally, the last line changes your display to the new video resolution mode.
In LMDE Xfce, these lines should be added to a file called ~/.xprofile (note the beginning period, meaning it is a hidden file in your /home/<username> folder). My ~/.xprofile file is:
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cws@cws-desktop:~$ cat .xprofile
xrandr --newmode "1280x1024" 109.00 1280 1368 1496 1712 1024 1027 1034 1063 -hsync +vsync
xrandr --addmode 'VGA-1' 1280x1024
xrandr --output 'VGA-1' --mode 1280x1024
I have a Etronix 1701B 17" LCD monitor, which I have had for a number of years. The EDID is fine for Windows, but is not read properly by Linux. The technique was copied and modified from
http://www.ubuntugeek.com/how-change-di ... randr.html and
https://wiki.ubuntu.com/X/Config/Resolution , both of which are good references for changing resolution modes, and the second is good for adding a second monitor.