Ubuntu@Laptop: turning off internal speakers on connecting headphones

In most cases, Ubuntu has already configured everything.. just one check-box needs to be checked.

Open System->Preferences->Volume Control

There should be a tab named "Switches".
(If its not present, Goto Edit->Preferences and check "Headphone jack sense")

Goto the "Switches" Tab, and check the box in front of "Headphone Jack sense".
Thats it!!

If by default the options mentioned here are not there, then look for answers in the ubuntu forums.

Excellent introductary presentation on algorithms

Introduction to Algorithms

View SlideShare presentation (tags: algorithms emergent technologies)

Ubuntu@Laptop: Wireless Button LED does not work

I have a HP Compaq nc6220 laptop (really a dabba!!)

I installed ubuntu 8.04 on it, and since there's a rule that not everything should be working - my wireless button was dysfunctional!

Doing a 'sudo lshw -C network' after pressing the wireless button showed that the button is actually toggling the radio, its just not making the LED glow.

i.e. after pressing it once, the command output will have the string -
wireless=radio off

and after pressing it again, it will contain -
wireless=unassociated

Solution -
Find the driver module for the wireless card, in my case it was ipw2200.

Remove the module:
sudo modprobe -r ipw2200

And insert it again with the led option:
sudo modprobe ipw2200 led=1

This makes the LED blink when the radio is turned on.

Note: This setting is lost on reboot, so add these two commands in /etc/rc.local

Display acronyms de-mystified

Normal Screen (Aspect Ratio 4:3)

• VGA - 640 X 480
• SVGA - 800 X 600
• XGA - 1024 X 768
• QVGA - 1280 X 960
• SXGA+ - 1400 X 1050
• UXGA - 1600 X 1200
• QXGA - 2048 X 1536
• QSXGA+ - 2800 X 2100
• QUXGA - 3200 X 2400
• HUXGA - 6400 X 4800

Wide Screen (Aspect Ratio 5:4 or 16:9)

• WXGA - 1280 X 800
• WXGA+ - 1440 X 900
• SXGA - 1280 X 1024
• WSXGA+ - 1680 X 1050
• WUXGA - 1920 X 1200
• QSXGA - 2560 X 2048
• HSXGA - 5120 X 4096