Generation of Computers

Generation of Computers

Computers have come across a long way to acquire the current form and capability. It took around 50
years of continuous developments to bring the computer in its present form. The evolution of  computers is mainly divided into five main generations. The computers of each of these generations have different properties.

First Generation Computers (1940–1956)

The U.S. census Bureau developed the first business computer in the year 1951. This computer was called Universal Automatic Computer (UNIVAC). It used vacuum tube circuits for processing. The computers that used vacuum tube circuits were called the First Generation computers. The vacuum tube circuits contained a filament that was heated to emit electrons.
The main features of the first generation computers were as follows:

• They used vacuum tubes.
• They had a very big size.
• They consumed huge electricity.
• They were prone to failures.
• They generated a lot of heat.
• They only supported machine language.

Second Generation Computers (1956–1964)

Bell Labs of U.S.A. invented transistors that were used instead of vacuum tubes. Transistors
are electronic circuits that are small in size. They do not emit electrons and do not require any heating. The computers that used transistors were called the Second Generation Computers.
The main features of the second generation computers were as follows:

• They used transistors instead of vacuum tubes.
• They were smaller in size as compared to the first generation computers.
• They generated lesser heat.
• They were more reliable and faster than the first generation computers.
• They used core memories, magnetic tapes and disks.
• They used lesser electricity.
• They could be programmed by using machine as well as assembly
• language.

Third Generation Computers (1964–1971)

The Third Generation Computers used Large Scale Integrated (LSI) circuits for processing. The LSI circuits were invented in mid 1960s. LSI circuits integrate several circuit components into a single chip.
The main features of the third generation computers were as follows:

• They used integrated circuits
• They had a small size as compared to the second generation computers.
• They consumed less electricity.
• They were faster and reliable than the second generation computers.
• They supported high level language.

Fourth Generation Computers (1971–Present)

Very Large Scale Integrated (VLSI) chips were invented in the year 1969. The computers that used VLSI chips and ULSI (Ultra Large Scale Integrated) were called the Fourth Generation Computers.
The main features of the fourth generation computers are:

• They contain high-speed microprocessors.
• They contain huge storage volumes in the form of magnetic and optical storage.
• They contain main memories up to GBs (Gigabytes).
• They are companied by great developments in the fields of networks

Fifth Generation Computers (Future)

Recent research has focused on developing “thinking computers”. These computers are called the Fifth Generation Computers. Fifth generation computers will have the power to learn and apply knowledge to solve a problem. They would be able to work like humans.

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