Different Generations Of Computers

Generation	Period	Main Electronic Components	Main Computers	Operating System
1	1945-56	Vacuum tubes, Flip-flops	UNIVAC, ENIAC	Mainly Batch Operating System
2	1956-63	Transistors	IBM-700, IBM-1401	Time Sharing Operating System
3	1964-71	Integrated Circuits (IC’s)	IBM-1620, ATLAS, ICL-1901, IBM- 360, IBM- 370	Real Time and Time Sharing Operating System
4	1971- Present	Micro processors (LSI-Large Scale Integration)	NCR-395, CDC-1700,APPLE, DCM	Time Sharing network
5	Present & beyond	Optical Fibre, Artificial Intelligence (VLSI and VVLSI- Very Very Large Scale Integration )	------------	Windows( Xp, 7, 8, 8.1, 10) Fedora, Macintosh OSX, Mac OS and many more…

First Generation (1940-1956) Vacuum Tubes

The first computers used vacuum tubes for circuitry and magnetic drums for memory, and were often enormous, taking up entire rooms. They were very expensive to operate and in addition to using a great deal of electricity, generated a lot of heat, which was often the cause of malfunctions.

First generation computers relied on machine language, the lowest-level programming language understood by computers, to perform operations, and they could only solve one problem at a time. Input was based on punched cards and paper tape, and output was displayed on printouts.

The UNIVAC and ENIAC computers are examples of first-generation computing devices. The UNIVAC was the first commercial computer delivered to a business client, the U.S. Census Bureau in 1951.

Second Generation (1956-1963) Transistors

Transistors replaced vacuum tubes and ushered in the second generation of computers. The transistor was invented in 1947 but did not see widespread use in computers until the late 1950s. The transistor was far superior to the vacuum tube, allowing computers to become smaller, faster, cheaper, more energy-efficient and more reliable than their first-generation predecessors. Though the transistor still generated a great deal of heat that subjected the computer to damage, it was a vast improvement over the vacuum tube. Second-generation computers still relied on punched cards for input and printouts for output.

Second-generation computers moved from cryptic binary machine language to symbolic, or assembly, languages, which allowed programmers to specify instructions in words. High-level programming languages were also being developed at this time, such as early versions of COBOL and FORTRAN. These were also the first computers that stored their instructions in their memory, which moved from a magnetic drum to magnetic core technology.

The first computers of this generation were developed for the atomic energy industry.

Third Generation (1964-1971) Integrated Circuits

The development of the Integrated Circuit was the hallmark of the third generation of computers. Transistors were miniaturized and placed on silicon chips, called semiconductors, which drastically increased the speed and efficiency of computers.

Instead of punched cards and printouts, users interacted with third generation computers through keyboards and monitors and interfaced with an operating system, which allowed the device to run many different applications at one time with a central program that monitored the memory. Computers for the first time became accessible to a mass audience because they were smaller and cheaper than their predecessors.

Fourth Generation (1971-Present) Microprocessors

The Macro Processor brought the fourth generation of computers, as thousand of integrated circuits were built onto a single silicon chip. What in the second generation filled an entire room could now fit in the palm of the land. The Intel 4104 chip, developed in 1941, located all the components of the computer—from the Central Processing Unit and memory to input/output controls—on a single chip.

In 1981 IBM introduced its first computer for the home users, and in 1984 Apple introduced the Macintosh. Macro processors also moved out of the real of desktop computers and into many areas of life as more and more everyday products began to use macro processors.

As these small computers became more powerful, they could be linked together to form networks, which eventually led to the development of the Internet. Fourth generation computers also saw the development of GUIs, the Mouse and handheld devices.

Fifth Generation (Present and Beyond) 

Artificial Intelligence

Fifth generation computing devices, based on Artificial Intelligence, are in development, though there are some applications, such as voice recognition, that are being used today. The use of Parallel Processing and superconductors is helping to make artificial intelligence a reality. Quantum computation and molecular and Nanotechnology will radically change the face of computers in years to come. The goal of second-generation computing is to develop devices that respond to Natural Language input and output are capable of learning and self-organisation