Briefly Explain the History of Computer

1. First generation (1946 – 1956) – Includes those computers, which were based on the use of the vacuum tubes. Such computers were very big in size with limited values for memory and processing. The vacuum tubes were used for storage and processing of the data but these tubes generated a lot of heat and also used a great amount of power. These type of computers were used for scientific and engineering purposes, involving programming, firstly in the machine language and then in the assembly language. The main drawback of such a computer was that it had a very short life span – which further resulted in low MTBF (Mean Time Between Failure) of the order of an hour. For e.g. the ENIAC – had only 20 registers for storage and could only support 5,000 additions per second.

2. Second Generation (1957 – 1963) – During this time period, such computers came to the stage that used transistors, instead of the vacuum tubes for the storing and processing of the data. These transistors were made of the germanium semi conductors’ material making them more compact in size and also more reliable in nature. Unlike the vacuum tubes, these transistors consumed less power and as a result of this MTBF became longer. These second generation computers were more accurate and faster and also cheaper than the first generation computers. Such a computer could have up to 32 KB of RAM, supported by a speed of up to 2 lakh to 3 lakh instructions per second. Computers of this generation were used only in the works involved in inventory, pay roll, marketing, accounting etc.

It was during this generation only, that the world observed the upcoming of the various high level languages like ALGOL, COBOL, FORTRAN and SNOBOL.

3. Third generation (1964 – 1979) – This generation saw the development of a new technology to be used in the computers called the integrated circuits or the integrated chips. In the computers of this generation, in place of the transistors silicon chips were used, which were known as the integrated circuits or chips. These circuits improved the working of the computer to a great deal increasing speed, reliability by a factor of 10 and power dissipation was reduced by a factor of 10.

The integrated circuits were made of the transistors, resistors, capacitors brought together on a single silicon chip. These circuits were made by printing hundreds and then thousands of silicon chips, called as the semi conductors.

In this generation, memory of the computers went up to 2 MBs of RAM with the speed of the CPU going up to 5 Million Instructions per Second (MIPS). As a result of this, computers now were able to find work for themselves in the field of business, airlines reservation systems etc.

The computer of this generation had very good CPU capabilities leading to the development of Integrated Data Base Management Systems.

4. Fourth generation (1980 onwards) – The computers being used by us today belong to this generation. In the fourth generation computers, VLSIC’s (very large scale integrated circuits) are used which consist of 2,00,000 to over 3,00,000 circuits per chip. Memory of the computer has now gone up to over 2 Giga Bytes in large computers with the speed of processing going up to 200 MIPS.

5. Fifth generation – This type of computers involve more of expectations than the reality. Such computers are expected to follow parallel processing procedures, with artificial intelligence and intricate mathematical models.