CLASS - VI | CHAPTER -1 ( Computer Story )

 CHAPTER-1 

Computer – Computer Story

Generations of Computers

Generations	Parts Used	Feature
First Generation computers (1940-1956)	Vacuum Tube	These computer were very big They worked slowly and generated a lot of heat.
Second Generation computers (1956-1963)	Transistors	These were smaller, faster and more reliable than earlier computers. They used punch cards and magnetic tapes to store data
Third Generation computers (1963-1971)	Integrated Circuits (ICs)	These were smaller, faster and more reliable than 2nd generation computers. The use of keyboard and monitor started for the first time. Disk storage also began.
Forth Generation computers (1971- Present)	Microprocessor	These computers are even smaller, more powerful and reliable. They support a host of input, output, and storage devices.
Fifth Generation computers (Present & beyond)	Artificial Intelligence	The computers of this generation are still in the nascent stage of development.

Classification of Computers

Computer can be classified on the  basis of their size and speed.

Microcomputer

Microcomputer are small computer whose CPU is a microprocessor, contained on a single integrated circuit chip. These computer are also called personal computers (PCs). The major type of these are Desktop, Laptop and hand held (Tablet PCs, Smart phones) computers.

Minicomputers

Minicomputers came into existence in 1960s. Those days mainframe computers were very expensive. Minicomputers were powerful and available at a reasonable price, so users switched over to them. Minicomputer are normally referred to as mid-range servers now.

Mainframe Computers

Mainframes are huge computers that can occupy an entire room or even a whole floor. A mainframe can accommodate many users at a time. Terminals are used to connect a user to this computer. A terminals is a device which has a keyboard and a screen integrated together. By using a terminal each user can give inputs into the computer and get the output on his/her monitor. The mainframes are normally referred to as enterprise servers.

Super Computers

As the name “supercomputer” specifies, these are the most powerful computers. A super computer uses multiple CPUs to work on a problem using the concept of Parallel processing. Supercomputers are used for highly calculation intensive task such as weather forecasting, climate research (like global warming).

Programming Language

A programming language is a special type of language that we can use to give instruction to the computer. All the software and programs that run on the computer are developed using one computer language or the other.

Type of Programming Languages

 Machine Language: The Machine language is the elementary language of a computer that consists of binary digits (0 and 1) only.

Assembly Language: The Assembly Language is close to the Machine language but in assembly language, binary operation codes are replaced by the mnemonics.

Machine and Assembly languages are also called low level language as they are linked with the hardware.

High Level Language: High Level Languages (HLLs) are programming languages designed for users to write instruction in English-like statements (like c=a+b) rather than in the Machine language or using Mnemonics. Any one of the several programming languages that resemble the English language.