Learn the evolution of computers-Full detail information about the evolution of computer from 3000BC to 2020

Computers are seen everywhere around us, in all spheres of life.

May it be the field of education and research, travel and tourism, weather forecasting, social networking, e-commerce, or any other, computers have now become an indispensable part of our lives.

The manner, in which computers have revolutionized our lives because of their accuracy and speed of performing a job, is truly remarkable. today no organization can function without a computer.

 In fact, various organizations are trying to become paper-free owing to the benefits of computing devices to portable high-speed computers that we see today.

Evolution of Computers

The growth of the computer industry started with the need for performing fast calculations.

The manual method of computing was slow and prone to errors.  So attempts were made to develop faster calculating devices. 

The journey that started from the first calculating device i.e.  Abacus has led us today to extremely high speed calculating devices.  

Let us first have a  look at some early calculating devices and then we will explore various generations of computers.

Abacus

Abacus was discovered by the Mesopotamia's in around 3000 BC.  An abacus consisted of beads on movable rods divided into two parts. 

The addition and multiplication of numbers were done by using the place value of digits of the numbers and position of beads in an abacus.

An Abacus

The Chinese further improved on the abacus so that calculations could be done more easily.  Even today abacus is considered an apt tool for young children to do calculations.

In an abacus, each row is thought of as a ten’s place. 

From right to left, row  no-1  represents the one’s column and the second column represents ten’s place. The third column represents the hundred’s place and so on.

The starting position of the top beads (representing the value of five) is always towards the top wall of the abacus while the lower beads (representing the value of one) will always be pushed towards the lower wall as a starting position.

Napier’s Logs and Bones

The idea of a logarithm was developed by  John  Napier in  1617.  He devised a  set of numbering rods known as  Napier’s  Bones through which both multiplication and division could be performed. 

These were numbered rods that could perform multiplication of any number by a  number in the range of  2-9.  There are  10  bones corresponding to the digits 0-9 and there is also a special eleventh bone that is used to represent the multiplier.

By placing bones corresponding to the multiplier on the left side and the bones corresponding to the digits of the multiplicand on the right,  the product of two numbers can be easily obtained.

Napier's Logs

Pascaline

Blaise  Pascal,  a  French mathematician invented the adding machine in  1642  that was made up of gears and was used for adding numbers quickly.  

This machine was also called Pascaline and was capable of addition and subtraction along with carry-transfer capability. It worked on the clock-work mechanism principle.  

It consisted of various numbered toothed wheels having unique position values.  The addition and subtraction operations were performed by the controlled rotation of these wheels.

Pascaline

Leibnitz’s Calculator

In  1673  Gottfried  Leibnitz,  a  German mathematician extended the capabilities of the adding machine invented by Pascal to perform multiplication and division as well.

The multiplication was done through repeated addition of numbers using a  stepped cylinder each with nine teeth of varying lengths.

Leibnitz’s Calculator

Jacquard’s Loom

In order to make the cotton-weaving process automatic, Joseph Jacquard devised punch cards and used them to control looms in  1801.  

The entire operation was under a program’s control. 

Through this historic invention, the concept of storing and retrieving information started.

A difference engine and Analytical Engine

Charles  Babbage,  an  English mathematician developed a  machine called  Difference Engine in  1822  which could calculate various mathematical functions,  do polynomial evaluation by finite difference, and theoretically could also solve differential equations.

Thereafter in 1833, he designed the Analytical Engine which later on proved to be the basis of modern computers.

This machine could perform all four arithmetic operations as well as comparison. It included the concept of the central processor, memory storage, and input-output devices.  Even the stored information could be modified.

Owing back to the lack of technology of the time, the Analytical Engine was never built. Its design remained conceptual.

Both these great inventions earned him the title of ‘Father of Modern Computers’.

Difference Engine and Analytical engine

Mark 1

In 1944 Prof Howard Aiken in collaboration with IBM constructed an electromechanical computer named Mark 1 which could multiply two 10 digit numbers in 5 seconds. 

This machine was based on the concept of  Babbage’s  Analytical engine and was the first operational general-purpose computer that could execute preprogrammed instructions automatically without any human intervention.

Mark 1

In 1945, Dr. John Von Neumann proposed the concept of a stored-program computer. As per this concept, the program and data could be stored in the same memory unit. 

The basic architecture of the Von Neumann computer is shown in the picture below

Von Neumann Computer

According to Von Neumann architecture, the processor executes instructions stored in the memory of the computer.  

Since there is only one communication channel,  the processor at a time can either fetch data or an instruction. 

That means at one point in time either the data or an instruction can be picked (fetched) from the storage unit for execution by the processor.  

Hence execution takes place in a sequential manner.  This limitation of Von Neumann Computer is known as Von Neumann bottleneck. EDVAC (Electronic  Discrete  Variable  Automatic  Computer)  was the first stored-program computer developed in  1952.  

After the invention of the first electronic computer  ENIAC (Electronic  Numerical  Integrator and  Calculator)  in  1946, computer technology improved tremendously and at a very fast pace.

Generation of Computers

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Growth in the computer industry is determined by the development of technology. 

Each phase/generation of computer development is characterized by one or more hardware/software developments that distinctly improved the performance of the computers of that generation.

 Based on various stages of development, computers can be divided into different generations.

The First Generation (1942-1955)

The first generation computers used the concept of  ‘stored program’  and were characterized by vacuum tubes.  

A  vacuum tube is a  delicate glass device that can control and amplify electronic signals. The first generation computers were made using thousands of vacuum tubes and were the fastest calculating devices of their time. 

These computers were very large in size, consumed a lot of electricity, and generated a lot of heat. UNIVAC  1  was the first electronic computer of this generation and was used for business applications.

Salient features of First generation computers:

• Used vacuum tubes to control and amplify electronic signals
•  Huge computers that occupied a lot of space High electricity consumption and high heat generation
•  Were unreliable since they were prone to frequent hardware failures
•  Commercial production was difficult
•  They were very costly and required constant maintenance
•  Continuous air conditioning was required
•  Programming was done in machine language although assembly language also started at the end of this generation Example: ENIAC, EDVAC, UNIVAC 1

Note: ENIAC weighed about 27 tons, was of the size 8 feet * 100 feet * 3 feet and

consumed around 150 watts of power.

The Second Generation (1955–1964)

The second-generation computers were characterized by transistors. 

A transistor is a solid-state semiconductor device that revolutionized the electronics industry. Transistors were smaller, highly reliable, consumed less electricity, and generated less heat.

 Also, magnetic core memories were developed during this generation. 

These are tiny ferrite rings that can be magnetized in either clockwise or anticlockwise direction so as to represent binary 1 or binary 0. 

Magnetic cores were used as primary memories. 

Later

magnetic disks also came into existence and were used as secondary storage devices.

All these new developments – transistors, magnetic core memory, and magnetic disk

storage devices made the computers more powerful and reliable. 

This further led to the existence of operating systems. Programming languages like FORTRAN, COBOL, Algol, etc. also developed. 

Commercial applications of the computer increased and now the computers were used in business and industries for applications like payroll, employee

management, inventory control, etc. IBM 1401 and IBM 1620 were popular computers of

this generation.

Salient Features of Second-generation computers:

•  Use transistor-based technology
•  Were smaller and less expensive as compared to first-generation
•  Consumed less electricity and emitted less heat
•  Magnetic core memories and magnetic disks were used as primary and secondary     storage respectively
•  The first operating system developed
•  Programming in assembly language and in the later part high-level languages was used
•  Wider commercial use but commercial production was still difficult
•  They also required constant air-conditioning.

Examples: IBM 1401, IBM 1620, UNIVAC 1108

The Third Generation (1964-1975)

In 1964, the Integrated Circuits or ICs or chips revolutionized the electronic industry

and started the third generation of computers. 

An IC is a small silicon chip or wafer made up of extremely purified silicon crystals. It has numerous transistors, capacitors, resistors, and other elements of an electronic circuit. 

A small scale integration (SSI) chip used to have about 10 transistors on a single chip and a medium-scale integration (MSI)

chip had about 100 transistors per chip. The size of memories also increased. 

Various mainframe computers and minicomputers were developed during this generation. Even

operating systems with multitasking and multiprogramming features (you will learn

about these terms in the next chapter) were developed. 

Since IC made the computers highly reliable, relatively inexpensive, and faster, computers these days were found in areas of education, small businesses, and offices along with industrial and business

applications. IBM 360 was a very popular third-generation computer.

Salient Features of Third Generation computers:

•  Used integrated circuits
•  Computers were smaller, faster, and more reliable
•  Low power consumption and less emission of heat as compared to the previous generation's

Examples: IBM 360 series, Honeywell 6000 series

The Fourth Generation (1975 onwards)

In this generation Large Scale Integration (LSI) and Very Large scale integration (VLSI)

the technology was used by which up to 300,000 transistors were used on a single chip.

Thus integration of complete CPU on a single chip was achieved in 1971 and was

named microprocessor which marked the fourth generation of computers.

The computers based on microprocessor technology had faster accessing and processing

speeds. 

In addition to this, the increased memory capacity further made the computers

more powerful and also more efficient operating systems were developed for these

computers. 

New concepts of microprogramming, application software, databases,

virtual memory etc were developed and used.

The computers that we use today belong to this generation. These portable computers

can be carried from one place to another owing to their compact size. They are much

more accurate. 

Even memory sizes have become phenomenal. Commercial production

of these computers is easier and they are the least expensive, compared to the earlier

generation of computers.

Also, computer networks starting coming up during this generation. It is today one of

the most popular means to interact and communicate with people.

Salient features of Fourth-generation Computers

•  ICs with LSI and VLSI technology
•  Microprocessors developed
•  Portable computers developed
•  Networking and data communication became popular
•  Different types of secondary memory with high storage capacity and fast access developed
•  Very reliable, powerful, and small in size
•  Negligible power consumption and heat generation
•  Very less production cost

Fifth Generation Computers

Fifth Generation computers are still under development. This generation is based on the

concept of artificial intelligence. 

In simple terms, the computers of this generation are supposed to behave like humans. 

The principles of parallel processing (many processors are grouped together) and superconductivity are being used to develop devices that respond to human languages and will have the ability to apply previously gained knowledge to execute a task. 

They will let them make decisions of their own to execute a task. Some applications like voice recognition, visual recognition are a step in

this very direction.

Salient features of fifth-generation computers:

•  Parallel Processing
•  Superconductivity
• Artificial Intelligence