What are the 5 Generations of Computer

 
Introduction
The 5 generations of computer refers to set of computers that were developed with more advanced technology. Meanwhile, in each of these generations of computer, there is always a significant improvement in the power and speed of processing tasks.
 The good part of computers developed from 1940s till date is the reduction in size, price and increase in power and efficiency when it comes to computing.

In this article, you will learn about the 5 generations of computers, year they were invented and the improvement in technology that gave birth to the invention of these computers.

The First Generation of Computers (1940–1956)
This set of computers were very large in size to the extent that they occupied entire rooms and they used vacuum tubes for magnetic drums and circuitry for main memory. Their maximum storage capacity was only 20,000 characters. These computers used huge amount of electricity and generated a lot heat (the excess heat makes them to malfunction) and also low to operate.

These computers relied on low level programming language (machine language) to process any task and were able to complete one task at a time. For a new task to be setup, it will take the operators days or weeks. The mode of input was paper tape and punch cards and results was generated in printouts.
Some of the computers that were introduced in this first generation are EDVAC ( Electronic Discrete Variable Automatic Computer), UNIVACI ( Universal Automatic Computer), ENIAC ( Electronic Numerical Integrator and Computer), IBM-701 and IBM-650.

The Second Generation of Computers (1956–1963)
After the invention of transistors at Bell Laboratory in the year 1947, it was observed that these transistors are far more better than the vacuum tubes used in the first generation of computers. However, the use of these transistors were not popular until 1950s were second generation of computers were introduced.

In the second generation of computers, transistors were used to replace vacuum tubes which resulted to enormous reduction in computer's size, price, processing spread and more energy efficient as well as generated less heat compare to its predecessor. Also, improvement was made on hardware devices hence the introduction of the magnetic tape, magnetic core memory and magnetic disk.
However, the second generation still uses paper tape and punch cards as means of accepting input.

Furthermore, as more advancement was made in computers, more powerful and reliable languages that aids programmers to give instructions to the computer in better ways was invented known as the High Level Programming Language (Assembly Language). Examples of this Assembly Language were early release (versions) of COBOL and FORTRAN. In this set of computers, magnetic core were used as primary memory and magnetic disk and tape as secondary memory. Examples of computers in this second generation are, IBM 1620, IBM 7094, CDC 1604, CDC 3600, UNIVAC 1108 

The Third Generation of Computers (1964–1971)
In third generation, transistors were replaced with Integrated Circuits invented by Jack Kilby of Texas Instruments and Robert Noyce of Fairchild Semiconductor. A single IC contained huge number of transistors and this makes computers become smaller in size, faster in speed, required less electricity and much more reliable. Users started communicating with computer through keyboard (input device) instead of punch cards, monitor (output device) to display results instead of printouts.

In this generation, computers were able to run more than one application at a time with a centered application monitoring the performance of the memory.

The Fourth Generation of Computers (1971–1980)
In this generation, microprocessor or Very Large Scale Integration (VLSI) Circuits where invented and used to replaced the ICs of the third generation. VLSI is a chip that contains millions of transistors and other relevant circuit elements. 
In fourth generation, computers became more powerful and faster, less expensive and affordable to everyone. These computers also used real time sharing and distributed database. 
Examples of this fourth generation computers are DEC 10, STAR 1000, PDP 11, CRAY-1(Super Computer) and CRAY-X-MP(Super Computer)

The Fifth Generation of Computers (1980 till date)
In fifth generation, the Very Large Scale Integration technology was replaced with Ultra Large Scale Integration (ULSI). In this phase of technology it was possible to produce microprocessor with ten million electronic components.
These computers also used Artificial intelligence software and Parallel Processing hardware. The use of programming languages like C, C++, .Net, Java e.t.c was also possible through this  computers.
However, it is worth to note that this generation is still in development.
Examples of fifth generation computers includes Notebook, Desktop, UltraBook, Laptop and ChromeBook