A summary about redementary knowledge of computer (from 老男孩教育）

How the computer works?

 

three foundational part: CPU \ memory \ disk

1. CPU is the place to process information.

 

1. Memory is a temporary situation to storage information, which is driven by the electricity. So, what it storages will disappear when we cut down the currency.

 

1. Disk is a place to storage information permanently. Namely, it storages information by physical rewrite, like engraving wood but we can recover it anytime we want.

 

       It is very abstract, so let’s dip into how they function!

There are two space to storage information: Memory and Disk. CPU is a core processor. Memory and Disk is to provide raw materials. For example, when we open a software, CPU will instruct the Memory to read Disk so that the target software will attend in Memory. And CPU will process the software in Memory.

       Disk is very big. However, it is hardly for disk to run fast. We cannot call what we want quickly! When the software functions in Memory, it can run fast. Because CPU can get information in Memory quicker than Disk.

       In conclusion, CPU is to process. Memory is to storage information temporary. When software in Memory, they seemingly run at high-speed road. By contrast, disk is like a common road.

 

Let’s talk about the defect when you has a bad CPU, Memory and Disk.

CPU: slow process

Memory: slow process, slow open

Disk: slow open (because open one thing is similar to transport it to Memory

 

 

So, what the information in computer look like !

control the open and close of currency

       The currency run in the computer will be divided in to countless branch. Every currency run in a independent crystal valve( not in Disk)

       Every currency can represent two symbol yes or no. These is the reason why computer use binary system.

       Also, in the disk, many thing is easily to show two condition. Upper or lower. Maybe other method to represent.

      

       How binary system can present information. Let’s assume eight crystal valve as a group called byte( one crystal valve is a bit) Therefore, one byte can represent 2^8 numbers. When can connect 1 to a, so 3 which in computer is 11 can connect to c. The word we type in will translate into electrical signal. Is it amazing?!!! In computer, letters are just characters presenting a pattern in screen, which means ‘a’ is not ‘a’!

 

 

There are many characters not just English!

ANSI is the first coding schedule. It only includes English and some special characters like ‘=-/*’.

China created GB2312->BGK->GBI18030 to ass Chinese words in coding schedule.

GBK is compatible to ANSI, because it is a extra schedule in just one position in ANSI. When we type the num of Chinese position. Our computer will refer a new schedule!

 

However, there are many languages need to be added. There is no place for them! 256 position are used out! The Unicode appear. Every word are presented by two bype. So, now we can have many position to storage characters! The default of this action is also apparent. The English words are originally represent by one byte. Too many zero in another byte will very slow down the computer. So, the UTF-8 appeared! The English words use one byte to represent. And many complex characters like Chinese words are represented by three byte. How the computer distinguishes such byte mixed. I think may be in the first byte of Chinese words are same. So that computer can connect this byte to the one behind!

 

 

What is OS (operation system) and how it functions?

OS is a program. This program will guide computer to operate more efficiently. The software is bases on OS. And OS also connects to hardware. Like police to manage a disorder crowd. OS needs Memory to work.

 

 

What is computer language?

People need a easy-understand language to operate computer. It is hard for us to process by 1001011100(binary system) So we develop a new language to operate and computer can translate this new language to binary system that computer can understand.

Yes! Instruct computer to do what we want. We do not need to understand binary system but a good translator.