COMPUTER BASICS

COMPUTER OVERVIEW

A computer is a device that can be instructed to carry out an arbitrary set of arithmetic or logical operations automatically. The ability of computers to follow a sequence of
operations, called a program, make computers very flexible and useful. Such computers are used as control systems for a very wide variety of industrial and consumer devices. This includes simple special purpose devices like microwave ovens and remote controls, factory devices such as industrial robots and computer assisted design, but also in general purpose devices like personal computers and mobile devices such as smartphones. The Internet is run on computers and it connects millions of other computers.

HISTORY OF COMPUTER

The history of computing hardware covers the developments from early simple devices to aid calculation to modern day computers. Before the 20th century, most calculations were done by humans. Early mechanical tools to help humans with digital calculations, such as the abacus, were called "calculating machines", by proprietary names, or even as they are now, calculators. The machine operator was called the computer.
The history of the computer can be divided into six generations each of which was marked by critical conceptual advances.  

The Mechanical Era (1623-1945) The idea of using machines to solve mathematical problems can be traced at least as far back as the early 17th century, to mathematicians who designed and implemented calculators that were capable of addition, subtraction, multiplication, and division. Among the earliest of these was Gottfried Wilhelm Leibniz (1646-1716), German philosopher and co-founder (with Newton) of the calculus. Leibniz proposed the idea that mechanical calculators (as opposed to humans doing arithmetic) would function fastest and most accurately using a base-two, that is, binary system.  

Leibniz actually built a digital calculator and presented it to the scientific authorities in Paris and London in 1673. His other great contribution to the development of the modern computer was the insight that any proposition that could be expressed logically could also be expressed as a calculation, "a general method by which all the truths of the reason would be reduced to a kind of calculation" (Goldstine 1972).  

Inherent in the argument is the principle that binary arithmetic and logic were in some sense indistinguishable: zeroes and ones could as well be made to represent positive and negative or true and false. In modern times this would result in the understanding that computers were at the same time calculators and logic machines. 

The first multi-purpose, i.e. programmable, computing device was probably Charles Babbage's Difference Engine, which was begun in 1823 but never completed. A more ambitious machine was the Analytical Engine. It was designed in 1842, but unfortunately it also was only partially completed by Babbage. 

That the modern computer was actually capable of doing something other than numerical calculations is probably to the credit of George Boole (1815-1864), to whom Babbage, and his successors, were in deep debt. By showing that formal logic could be reduced to an equation whose results could only be zero or one, he made it possible for binary calculators to function as logic machines (Goldstine 1972).

COMPUTER GENERATION

First Generation of Computers (1942-1955)

The beginning of commercial computer age is from UNIVAC (Universal Automatic Computer).It was developed by two scientists Mauchly and Echert at the Census Department of United States in 1947. The first generation computers were used during 1942-1955. They were based on vacuum tubes. Examples of first generation computers are ENIVAC and UNIVAC-1.

Advantage

• Vacuum tubes were the only electronic component available during those days.
• Vacuum tube technology made possible to make electronic digital computers.
• These computers could calculate data in millisecond.

Disadvantages

• The computers were very large in size.
• They consumed a large amount of energy.
• They heated very soon due to thousands of vacuum tubes.
• They were not very reliable.
• Air conditioning was required.
• Constant maintenance was required.
• Non-portable.
• Costly commercial production.
• Limited commercial use.
• Very slow speed.
• Limited programming capabilities.
• Used machine language only.
• Used magnetic drums which provide very less data storage.
• Used punch cards for input.
• Not versatile and very faulty.

SECOND GENERATION COMPUTERS (1955-1964)

The second generation computers used transistors. The scientists at Bell laboratories developed transistor in 1947. These scientists include John Barden, William Brattain and William Shockley. The size of the computers was decreased by replacing vacuum tubes with transistors. The examples of second generation computers are IBM 7094 series, IBM 1400 series and CDC 164 etc.

Advantages

• Smaller in size as compared to the first generation computers.
• The 2nd generation Computers were more reliable
• Used less energy and were not heated.
• Wider commercial use
• Better portability as compared to the first generation computers.
• Better speed and could calculate data in microseconds
• Used faster peripherals like tape drives, magnetic disks, printer etc.
• Used Assembly language instead of Machine language.
• Accuracy improved.

Disadvantages

• Cooling system was required
• Constant maintenance was required
• Commercial production was difficult
• Only used for specific purposes
• Costly and not versatile
• Punch cards were used for input.

THIRD GENERATION COMPUTERS (1964-1975)

The Third generation computers used the integrated circuits (IC). Jack Kilby developed the concept of integrated circuit in 1958. It was an important invention in the computer field. The first IC was invented and used in 1961. The size of an IC is about ¼ square inch. A single IC chip may contain thousands of transistors. The computer became smaller in size, faster, more reliable and less expensive. The examples of third generation computers are IBM 370, IBM System/360,UNIVAC 1108 and UNIVAC AC 9000 etc.

Advantages

• Smaller in size as compared to previous generations.
• More reliable.
• Used less energy
• Produced less heat as compared to the previous two generations of computers.
• Better speed and could calculate data in nanoseconds.
• Used fan for heat discharge to prevent damage.
• Maintenance cost was low because hardware failure is reare.
• Totally general purpose
• Could be used for high-level languages.
• Good storage
• Versatile to an extent
• Less expensive
• Better accuracy
• Commercial production increased.
• Used mouse and keyboard for input.

Disadvantages

• Air conditioning was required.
• Highly sophisticated technology required for the manufacturing of IC chips.

FOURTH GENERATION COMPUTERS (1975-PRESENT)

The fourth generation computers started with the invention of Microprocessor. The Microprocessor contains thousands of ICs. Ted Hoff produced the first microprocessor in 1971 for Intel. It was known as Intel 4004. The technology of integrated circuits improved rapidly. The LSI (Large Scale Integration) circuit and VLSI (Very Large Scale Integration) circuit was designed. It greatly reduced the size of computer. The size of modern Microprocessors is usually one square inch. It can contain millions of electronic circuits. The examples of fourth generation computers are Apple Macintosh & IBM PC.

Advantages

• More powerful and reliable than previous generations.
• Small in size
• Fast processing power with less power consumption
• Fan for heat discharging and thus to keep cold.
• No air conditioning required.
• Totally general purpose
• Commercial production
• Less need of repair.
• Cheapest among all generations
• All types of High level languages can be used in this type of computers

Disadvantages

• The latest technology is required for manufacturing of Microprocessors.

FIFTH GENERATION COMPUTERS (PRESENT & BEYOND)

Scientists are working hard on the 5th generation computers with quite a few breakthroughs. It is based on the technique of Artificial Intelligence (AI). Computers can understand spoken words & imitate human reasoning. Can respond to its surroundings using different types of sensors. Scientists are constantly working to increase the processing power of computers. They are trying to create a computer with real IQ with the help of advanced programming and technologies. IBM Watson computer is one example that outsmarts Harvard University Students. The advancement in modern technologies will revolutionize the computer in future.

COMPUTER IMPACT

ADVANTAGES

Uses of computer in science and field.
Scientists use computers to develop theories, collect, analyze and test the data, and exchange of information electronically with colleagues around the world. Powerful computers can be used to generate detailed studies of how earthquake affect buildings or how pollution affects weather patter. Satellite based science applications have not been possible without the use of computer. Computers are being used for research space. They are also used to make different types of investigation in medical science to find out diseases and medicines for the respective diseases.

Uses of Computer in Educations field
Nowadays, mostly all schools, colleges, and universities are giving more emphasis to computer education including it in their curriculum. In these institutions in addition to giving solely computer education, computers have become essential for teaching other subjects as well. Classrooms and libraries are efficiently utilizing computers to make the education much more interesting. Unlike recorded television shows, computer aided education and computer based training packages are making learning much more interactive.

Uses of Computer in Communication
Electronic Mail is a facility supported by computers to send messages from one place to another. Email facilitates sending the messages from one person to different persons by the aid of computer and telephone line. Here each person/user has mail box which is accessed via terminals or workstations within the system by entering an account number and a password.

Uses of Computer Engineering and manufacturing Filed
The architects and engineers are extensively used computer in designing and drawing. Computers can create objects that can be viewed from all the three dimensions. By using the techniques like virtual reality, architects can explore houses that have been designed but not built. Automobile, aircraft, aerospace and ship designers use computer aided designing technique in the design of various types of vehicles. The manufacturing factories are using computerized robot to perform risky jobs. Besides, computer aided manufacturing can be used in designing and planning the product.

Uses of Computer in Banking Field
In the field of banking and finance, computers are extensively used. People can use the ATM services twenty four hours of the day in order to deposit and withdraw cash. When the different branches of bank are connected through the computer networks; then inter branch transactions can be done by the computers without any delay.

Uses of Computer in Business and industries
Many of today's successful small companies simply would not exist with computer technology. Each, year hundreds of thousands of individuals launch the business based at their homes or small office locations. They depend on computers companies. These tools enable business owners to handle tasks such as accounting, inventory management, marketing, payroll, and many others. Businesses are also using the networking of computers, where a number of computers are connected together to share the data and information. Use of Email and internet has changed the ways of being used business. Nowadays, computers are used to design the product, ship and process control in the industries. As a result, small business and industries become most self sufficient, competitive and reduce their operating expenses.

The Social Impact of Computer in Our Society
From the time of the invention of the computers to the present day, computers have met tremendous changes. Time to time incorporation of the latest technical achievement has made the use of computer easier. More and more application have been developed and almost all the areas of the professions have been computerized. Computerization is continuously becoming an important part of many organizations. Computer have proved almost all the fields whether related to numeric processing or non numeric processing or document processing in the developed countries and all the walks of life. Computers have become the part of every organization. 

DISADVANTAGE

Beneficial or positive Impact of computer in our society

• Any professional individual like doctors, engineers, businessmen etc. undergo a change in their style or working pattern after they get the knowledge of computer.
• An individual becomes more competent to take a decisions due to the computer because all the information required to take the decision is provided by the computer on time. As a result, any individuals or institutions get success very fast.
• The person working at the managerial level becomes less dependent on low level staff like clerks and accountants. Their accessibility to the information increases tremendously. This improves their working patters and efficiency, which benefit the organization and ultimately affects the society positively.
• In common life also, an individual gets benefited with computer technology. When airports, hospitals, banks, departmental stores have been computerized, people get quick service due to the computer system.
• Computers have created new fields of employment. These employments are in the field of designing, manufacturing, teaching, etc.
• Due to any reasons, if the data stored in the computer is lost, the person responsible for handling the computer will have to tolerate a lot.
• People do not use their mind for common arithmetic, which gradually results in loss of their numerical ability.
• Today, any person who does not have the knowledge of computer is considered the second class citizens. 
• People have fear that growing children may lose their common sense abilities like numerical ability due to total dependence on computers. 
• Due to the computerization workload for the employees reduces many times. As a result, many organization may require to remove some of its employees. It produces the dissatisfaction and lack of security among the employees. Due to this, employees do not corporate the organization. As a result, the output can be disastrous.
• As a result of introduction of new technology in an organization, the organization may need to spend a tremendous amount on the training of its employees.