Ubuntu11.04 solve the problem of low resolution of external monitor

My notebook is ThinkPad, and the external monitor sets the resolution to 1680x1050.

first, familiarize yourself with the command:

Xrandr command line can be very convenient to switch the dual screen, commonly used in the following ways, others can explore their own:
Xrandr--output VGA--same-as LVDS--auto
Turn on the external monitor (highest resolution) and display the same content as the laptop LCD screen (clone)
Xrandr--output VGA--same-as LVDS--mode 1024x768
Turn on the external monitor (1024x768 resolution) to display the same content as the laptop LCD screen (clone)
Xrandr--output VGA--right-of LVDS--auto
Open External monitor (highest resolution), set to right extension screen
Xrandr--output VGA--off
Turn off the external monitor
Xrandr--output VGA--auto--output LVDS--off
Turn on the external monitor and turn off the laptop LCD screen (only works with an external monitor)
Xrandr--output VGA--off--output LVDS--auto
Turn off the external monitor while turning on the laptop LCD screen (only with the laptop LCD screen)

then, set it again in the following way.

1,
$CVT 1440 900
The results are as follows
# 1440x900 59.89 Hz (CVT 1.30MA) hsync:55.93 kHz; pclk:106.50 MHz
Modeline "1440x900_60.00" 106.50 1440 1528 1672 1904, 903 909 934-hsync +vsync

The value behind the modeline is used below. And then execute

2,
$xrandr
Get the display name, my VGA1, notebook for LVDS1, everyone and so on, not necessarily all the same

3,
$sudo xrandr--newmode "1440x900_60.00" 106.50 1440 1528 1672 1904-903 909 934-hsync +vsync
The parameter is the one behind the modeline in the CVT results, adjusted according to its own parameters.

4,
$xrandr
You can see the newly added setting.
Then add a new mode, execute

5,
$sudo xrandr--addmode VGA1 "1440x900_60.00"

Then set the line, we look at Xrandr's command in detail, www.linuxidc.com I just said my notebook in the left 1366x768, the external monitor in the right 1440x900 command, that is, the right extension screen 6,
$xrandr--output VGA1--mode 1440x900_60.00--right-of LVDS1
Open External monitor (highest resolution), set to right extension screen

Next, write the script:

#!/bin/sh

# monitor.sh
# Check whether the external monitor is connected:
# returns 0 on success
Xrandr | grep VGA | grep "Connected"
If [$?-eq 0]; Then
Xrandr--newmode "1680x1050_60.00" 173.00 1920x1080 2048 2248 2576 1083 1088 1120-hsync +vsync
#xrandr--newmode "1440x900_60.00" 106.50 1440 1528 1672 1904, 903 909 934-hsync +vsync
Xrandr--addmode VGA1 "1680x1050_60.00"
#xrandr--addmode VGA1 "1440x900_60.00"
Xrandr--output VGA1--mode 1680x1050_60.00--right-of LVDS1
#xrandr--output VGA1--mode "1440x900_60.00"--right-of LVDS1
Else
Xrandr--output VGA1--off
Fi

execute it again. Use the command Xrandr to see if you have the resolution you want to set. If not, execute the above script again. If you have:

Xrandr--output VGA1--mode 1680x1050_60.00--same-as LVDS1

To turn off the notebook display:

Xrandr--output LVDS1--off

that's good. You can also write a self-starter script that runs every time you boot.

View Ubuntu version command: cat/etc/issue