Basis of logic gates

This post is about logic gates, those one are the basis of calculation in base 2 (so also of computers).
In this post I'll talk about three logic gates:
-not
-and
-or

NOT Gate
The not gate return the opposite of the input. Here is the truth table:
in out
0   1
1   0

This is the standard symbol of NOT gate:

AND Gate
The and gate return positive just if all the inputs are positive. Here is the truth table:
a b out
0 0   0
0 1   0
1 0   0
1 1   1

This is the symbol of AND gate:
 

OR Gate
The or gate return positive just if one input is positive. Here is the truth table:
a b out
0 0   0
0 1   1
1 0   1
1 1   1

This is the symbol of OR gate:

This gates can be created using transistors like BC547, here is a short summary about logic gates made using transistors:

 

You can also download a pdf of this summary here.

Here are some photos of logic gates made using transistors:

 

I hope you like this post, if you have any question comment or send me an email to damianoandre@gmail.com

Bye, Dami

Some Google easter eggs

Hi, this post is about some funny easter eggs of Google:
-type "askew" to make the page tilt
-type "do a barrel roll" to make the page rotate of 360°
-type "zerg rush" to start a little arcade game
-type "where is chuck norris" and click I'm feeling lucky
-type "google gravity" and click I'm feeling lucky to see Google home page affected by gravity
-go to Google reader and press in order this keys to make some little ninja appear on the left:
Up, Up, Down, Down, Left, Right, Left, Right, B, A

Here is a sample video:

I hope you like this post, if you have any question please comment or send me an e-mail to damianoandre@gmail.com

Bye, Dami