Introduction of Computer

1. The word "computer" comes form "compute".that means 'calculate'.
2. Computer is electronic machine and calculating device .
3. Computer takes the input data from user . then computer machine converts in binary form 0 and 1. Then show the out put on monitor screen
4. Computer system is made up of both Hardware and software.
5. Without software a computer is useless.
6. Hardware refers to the physical components that make up computer system.

→ Full form of Computer Word.

• C→ Commonly
• O→ Operated
• M→ Machine
• P→ Particularly
• U→ Used for
• T→ Technical
• E→ Education
• R→ Research

→Full Form of Computer Meaning Commonly Operated Machine Particularly used for Technical and Educational Research.

Characteristics of Computers:-

There are following characteristics of computer that is.

1. Speed
2. Accuracy
3. Diligence
4. Versatility
5. Power of remembering
6. No Feelings

1) Speed

→ As you know computer can work very fast. It can perform in a few seconds, computer can perform millions (1,000,000) of instructions and even more per second. In other word computer can do in a few minutes .

2) Accuracy

→ Accuracy means computer calculate without mistake until the user do not enter the wrong data.

3) Diligence

→ It can continuously work for hour without creating any error and without tiredness.

4) Versatility

→ Versatility is on of the most wonderful things about a computer. It means the capacity to perform completely different type of work such as you may use computer to prepare payroll slips,electricity bill etc.

5) Power of remembering

→ Computer has the power of storing any amount of information data. Any information can be stored and recalled as long time.

6) No Feelings

→ They have no feeling no emotion because they are machines.

Generation of Computer

→"Generation" that means framework for the growth of computer industry based on technology developed include the hardware and software environment.

Types of Generation

There are Five generation of computer is used today that is.

1. First Generation(1942-1955)
2. Second Generation(1955-1964)
3. Third Generation(1964-1975)
4. Fourth Generation(1975-1989)
5. Fifth Generation(1989-Present)

1) First Generation(1942-1955)

The First Generation Computer used Vacuum Tube. J.P.Eckert and J.W.Mauchy invented the first successful electronic computer called ENIAC. ENIAC Stand for "Electronic Numeric Integrated And Calculator".

Advantages:-

• The First Generation Computer used of Vacuum Tubes.
• These computers could calculate in milliseconds.

Disadvantages:-

• These were very big size, and weight was about 30 tones,18000 Vacuum tube.
• These computers were very costly.
• Not reliable and constant maintenance is required.
• Electricity use 150000 watts.
• Very less work efficiency
• It store only a small amount of information.

2) Second Generation(1955-1964)

The Second generation computers were use of Transistor instead of vacuum tubes.

Advantages:-

• Use of Transistor
• Decreased Size of component.
• Low cost than first generation computers.
• Better speed, calculate data in microseconds

Disadvantages:-

• A Cooling system was required
• Only used for specific purposes.

3) Third Generation(1964-1975)

→ The Third Generation use of Integrated Circuits(IC).

→ IC invented by Robert Noyce and Jack Kilby In 1958-1959. where IC was a single component containing number of transistors.

Advantages:-

• Use of IC(Integrated Circuits).
• This generation of computers has big storage capacity.
• IC usein the small size of the computer.
• They used an operating system for better resource management.

Disadvantages:-

• IC chips are difficult to maintain.

4) Fourth Generation(1975-1989)

Advantages:-

• High Level Language is used in this type of computers.
• Less maintenance is required.
• Heat Generated is negligible.

Disadvantages:-

• Advance technology is required to make the ICs.

5) Fifth Generation(1989-Present)

This generation is based on artificial intelligence.and This generation is based on ULSI(Ultra Large Scale Integration) technology.

Few Examples:

Desktop, Laptop, NoteBook, UltraBook, Chromebook and other etc.

Advantages:-

• It is more reliable and works faster
• Different sizes and unique features are available.
• User friendly interfaces with multimedia features

Disadvantages:-

• They need very Low Level Languages.

Fig.

Types of computer:-

1. Micro Computer
2. Mini Computer
3. Mainframes
4. Super Computer

1) Micro Computer

Micro Computer is known as personal computer. Microcomputer were built single chip, that is CPU (Central Processing Unit), data memory (RAM, ROM), and I/O buses.

In other word technical meaning of the microcomputer is a micro controller.It is used in the home appliances such as TV, Mobile, refrigerator etc.

2) Mini Computer

The Mini computer is used in multi user system in which various user can work at the same time. this types of computer generally used for processing large volume of data in a organisation.

3) Mainframes

This types of computer are generally operate at very high speed, very large storage capacity and can the workk load of many users.

4) Super Computer

They are the fastest and most expensive computer. they have high processing speed compared to other computer.