[Tutorial] Add offline javadoc to eclipse

If you are working with eclipse, the javadocs come from internet. And eclipse takes a bit delay to show the docs. You can config your eclipse to use offline javadocs. This will make eclipse faster and you can see the docs without internet. These are the step:
1. Download javadocs:
Java 6: http://docs.oracle.com/javase/6/docs/
Java 7: http://docs.oracle.com/javase/7/docs/
Download the javadocs zip file and put in any where that you want.
2. Config eclipse:

Select Preferences

Select Installed JREs

Select the java version that you want to add docs and then select Edit

Select rt.jar package and then select Javadoc Location

Select Javadoc in archive and browse the zip that you downloaded

Done

How the CPU works

Every computer, smartphone, ... has a CPU inside. It's the brain of these devices. But how it works? After surfing around for a while, I found this. Take a look at how a CPU works:

Summary:
First, all devices have their own machine code to tell them what to do.
CPU takes a string of bits (machine code - designed by the manufacturer) and output another string of bits that do some special tasks or tell the devices what to do.
'The strings of bits' - intructions, are stored in RAM (random access memory). CPU read (input) these instructions and execute an output. The output maybe tell the hard disk to write somethings. Maybe store somethings to RAM again.