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1st Generation of Computer

Talha Hamid has knowledge about Computer Science and he is an experienced Computer Studies Writer.

First Generation Computer

First Generation Computer

First Generation Computer

1st Generation of Computer

Today the world has become modern due to technology. To complete every type of task, we use a computer. With the use of computers, every business has become online. Life is easy and comfortable with the use of computers.

But we don't think that how the computer invent. Today computers have become small, cheap and common. But in old age, computers were large, heavy and not so common as today. The history of computers starts with the birth of abacus over 5000 years ago. After this, the inventions of computers became started. In this article, I will discuss the first-generation of computers.

Vacuum Tubes were used in the 1st generation of computers to perform calculations. The period of 1st generation was 1946-1959. The first generation computer was ENIAC(Electronic Numerical Integrator and Calculator). The first generation of computers was heavy and large. They performed arithmetic calculations by using vacuum tubes. Their programming was very difficult. They consumed a lot of electricity. The first generation of computers had more disadvantages than advantages.

The most important computers were ENIAC and UNIVAC-1.UNIVAC was the world's first commercially electronic digital computer.

IBM 650 was the most popular first-generation computer.

Examples of first-generation computers are ENIAC, EDVAC, IBM-701, and IBM-650.

Here I have described briefly the first-generation of the computers.

What is Vacuum Tube?

A vacuum tube is an electron tube or valve is a device that controls the flow of electric current in a high vacuum between electrodes to which an electric potential difference has been applied.

1st Generation Computers

The first generation computer was ENIAC(Electronic Numerical Integrator and Calculator). It was a first general-purpose electronic digital computer which is designed by William Mauchly and John Eckert in 1942. But the machine was completed in 1945. It was designed to calculate artillery firing tables to be used by the United States Army's Ballistic Research Laboratory to help US troops during World War II.


The ENIAC computer was very heavy and large. Its size was 50-foot long basement room and Its weight was 30 tons. It had over 17,000 vacuum tubes. Vacuum Tube Computers used a lot of electricity.ENIAC consumed 150 kilowatts of power, in which 80 kilowatts were used for heating tubes, 45 kilowatts for DC power supplies, 20 kilowatts for ventilation blowers, and 5 kilowatts for punched-card auxiliary equipment.


The first use of ENIAC was to carry out arithmetic calculations.ENIAC was capable of doing 5000 additions per second. The ENIAC was decimal rather than a binary machine. Therefore, numbers were represented in decimal form, and arithmetic was performed in the decimal system. Its memory consisted of 20 accumulators, each capable of holding a 10-digit decimal number. Each digit was represented by a ring of 10 vacuum tubes.

Drawback of ENIAC

The major drawback of ENIAC was that its programming was complex and time-wasting. It was not a general use computer. To change its program meant essentially rewiring it, with punchcards and switches in wiring plugboards. It could take a team two days to reprogram the machine.

UNIVAC(Universal Automatic Computer)

It was the world's first commercially electronic digital computer. It was made by Eckert and Mauchly in 1947. It was delivered to the US Bureau of a census in 1951.

Advantages of First Generation of Computers

The advantage of the first generation of computers was that these computers fast and could calculate data in milliseconds.

Disadvantages of First Generation of Computers

1- Computers were larger.

2- They consumed a large amount of energy.

3-They heated very soon due to thousands of vacuum tubes.

4-They were not very reliable.

5-Air conditioning is required.

6-Constant maintenance was required.

7-Not portable.

8-Costly commercial production.

9-Very less work efficiency.

10-Limited programming capabilities

11-Use of punch cards

Limitations of First Generation of Computers

The operating speed was very low. Power consumption was very high. They required a large space for installation. The Programming capability was quite low. It's processing speed was also low.


The use of vacuum tubes in the first generation of computers revolutionized the world of technology. Many computers of the first generation were made from 1946 to 1959. Although, the first generation of computers has more disadvantages than its advantages. But its importance cannot be forgotten. Because after the first generation of computers, the second generation of computers was made.

Transistors were used in the second generation of computers.

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.

© 2020 Talha Hamid