In ancient times, people use their fingers or even stones and sticks for calculations. They always feel that calculations are difficult. To solve that problem, people were trying to invent some machine or even devices for calculation.   


It is believed that the first calculating device was  Abacus. The exact origin of the abacus and who invented it is still unknown. We have found some evidence of using abacus in Europe, China, Japan and Russia around 2400 BC. It is constructed as a frame with beads sliding on wires. We find area wise different designs for abacus.  In Japan it is called “Sorobon”.


Napier’s bones

In 1617 John Napier introduced a calculating device called Napier’s bones. He was a great mathematician from Scotland. This device was made by using multiplication tables. Multiplication can be reduced to addition and division to subtractions. 

Napier's bones
Napier’s bones

Pascaline or Pascal’s Calculator 

The Pascaline was designed and built by the French mathematician-philosopher Blaise Pascal. It was the first Calculator. Pascal designed the machine in 1642. After trying 50 prototypes, he presented the device to the public in 1645. This machine was mainly for Addition and Subtraction but Multiplication and Division could be possible through repeated addition or subtraction. Its success story is behind its carry mechanism, which adds 1 to 9 on one dial, and carries 1 to the next dial when the first dial changes from 9 to 0.


Difference Engine

In 1819 English mathematician and computer pioneer Charles Babbage began to construct a computing machine called difference engine. He completed it by 1822 and displayed a small sample before the public on 14th June of the same year. It was the first mechanical calculator. But it was not a general purpose calculator. It prepares numerical tables using a mathematical technique known as the method of difference. Today such types of tables are used for astronomical calculations. This same work is efficiently done by modern computers. But nearly a century and a half ago, the Difference Engine did much the same work, but slowly and mechanically.

Analytical Engine

The Analytical Engine was a mechanical general-purpose computer designed by Charles Babbage.It was first described by him in 1837 as the successor to his difference engine.
This machine was fully programmable and was able to perform any type of calculations. It consists of four components: the mill, the store, the reader, and the printer just like our modern computers. The mill was the calculating unit, similar to today”s central processing unit (CPU), and where data was stored was known as store, exactly like the memory and storage in modern computers; and the reader and printer were the input and output devices.The store was to be large enough to hold 1,000 50-digit numbers; this was larger than the storage capacity of any computer built before 1960.The reader was another new feature of the Analytical Engine. Data (numbers) were to be entered by punch card technique.
Some consider Charles Babbage as Father of Computer, because he gave the idea of modern computers. His Analytical Engine contained all the features of today’s computer.

Analytical Engine
Analytical Engine

After Babbage, different scientists and mathematicians worked on the development of computers and they invented different types of machines for calculations. Some of them are
The Electronic Numerical Integrator And Calculator (ENIAC) 1943-46
The Electronic Discrete Variable Automatic Computer (EDVAC)- 1946-52
The Electronic Delay Storage Automatic Calculator (EDSAC) -1947-49
The Universal Automatic Computer (UNIVAC) -1951

Generations of computer

First generation of computer( 1940-1956)

Vacuum tube was the main component of the first generation computer. To create a vacuum inside It (the glass tube), its gas is removed. Not only in computers the Vacuum Tube was also used in radios, telephones and other electronic systems. Vacuum Tube was the only electronic component available during those days. It was very bulky in size and produce huge amounts of heat which shortened the life of the tube.

The main features

  • Size : Thousands of vacuum tubes required to build one computer. These computers were very big in size and sometimes it takes the entire room.
  • Heat Production : Produced huge amounts of  heat. To control that heat, cooling system was required continuously . 
  • Storage Device : Magnetic drums .
  • Input Device : punch card was the only  way to input the  data. 
  • Output Device : Printer
  • Storage Capacity : Very small 
  • Price : Very costly.
  • Energy Consumption : Huge
  • Speed : Millisecond.
  • Reliability :Not reliable and continuous maintenance was required.
  • Language used :  machine language.
  • Use : Single purpose.  

Second generation of computer ( 1956 – 1962)

In this generation transistors were  used instead of Vacuum Tube. Transistors were invented in 1947 at Bell Labs in the United States. But around 1956 it started using in computers. It was made with silicon, which is a  semiconductor material. It  is cheaper and smaller than vacuum tube. Transistors have very long life and can operate on lower voltage.

The main features

  • Size :   smaller than the first generation
  • Heat Production : Produced less heat. Still cooling system was required
  • Storage Device : Magnetic tape
  • Input Device : punch card
  • Output Device : Printer 
  • Storage Capacity : Greater than  first generation computer.
  • Price : Cheaper than previous one
  • Energy Consumption : Less than first generation.
  • Speed : Microsecond.
  • Reliability : Reliable than first generation
  • Language used : Machine and assembly languages .
  • Use : More general purpose use.

Third generation of computer(1962-1971)

Third generation of computers used Integrated Circuits (ICs) in place of transistors. An integrated circuit is a set of electronic circuits on one small flat piece of semiconductor material that is normally silicon. IC is also called as chip. A single IC can work as many transistors, resistors, and capacitors. It was invented in 1960 but introduced in computers in 1962.
In this generation the keyboard is introduced as an input device. Keyboard had a-z alphabet accompanied with 0-9 numbers. General documentation was possible and with that, small DOS based games were available in those computers.

The main features

  • Size : Much smaller and became portable
  • Heat Production :Generate less heat. Less maintenance was required
  • Storage Device :Hard disc and floppy
  • Input Device :Keyboard
  • Output Device : Monitor 
  • Storage Capacity : Increased storage capacity
  • Price : Cheaper than previous generation
  • Energy Consumption : Less than 2nd generation.
  • Speed : Nanoseconds.
  • Reliability : Much reliable than 2nd generation
  • Language used : High level language  was used for programming. Operating system was introduced 
  • Use : Versatyle use.

Fourth generation of computer (1971-2010)

In 4th generation computer ICs were combined to form a single chip. Initially few ICs were combined. This is called Small Scale Integration (SSI). Gradually the number of ICs to be combined increased and we got Large Scale Integration (LSI), Very Large Scale Integration (VLSI) and finally Ultra Large Scale Integration (ULSI). Due to Ultra Large Scale Integration (ULSI) in this generation we get Laptop, Notebook, Mobile Phone and many more.

Fourth generation of computer
Fourth Generation of Computer

The main features

  • Size : Reduced and become more portable.
  • Heat Production : Negligible. 
  • Storage Device : HardDisk, CD,DVD, Pen Drive/Flash Drive
  • Input Device :Keyboard, mouse,Scanner, BCR,MICR, Microphone, etc.
  • Output Device : Printer, Speaker, Monitor. 
  • Storage Capacity : Unlimited. 
  • Price : Very cheap.
  • Energy Consumption : Very low.
  • Speed : Picoseconds.
  • Reliability :Highly reliable. Almost no maintenance is required .
  • Language used :  All high level language.
  • Use : Versatyle use.

Fifth generation of computer (2010-Present)

Fifth generation is based on AI(artificial intelligence). Artificial Intelligence means computers think and work like humans. There are so many examples we can find in the modern world for artificial intelligence. The very basic and common example of artificial intelligence is Google search. Driverless car is also an example of artificial intelligence. 

Fifth generation of computer
Fifth Generation of Computer

The main features

  • Size : Very small. Even fit on the palm of your hand.
  • Heat Production: Negligible. No AC is required. 
  • Storage Device : Hard Disk,CD,DVD, Pen Drive/Flash Drive, SSD .
  • Input Device :Keyboard, mouse,Scanner, BCR, MICR, Microphone, etc.
  • Output Device : Printer, Speaker, Monitor. 
  • Storage Capacity : Unlimited. 
  • Price : Very cheap.
  • Energy Consumption : Very low.
  • Speed : Faster than fourth generation
  • Reliability :Highly reliable. Almost no maintenance is required .
  • Language used :  All high level language.
  • Use : Versatile use.


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