Wednesday, November 2, 2011
Friday, May 20, 2011
Introduction
The word computer comes form the word compute, which means, To calculate. Hence, people usually consider a computer to be a calculating device that can perform arithmetic operations at high speed.
In fact, the original objective for inventing a computer was to create a fast calculating machine. However, more than 80% of work done by computers today is of non-mathematical or non-numerical nature. Hence, to define a computer merely as a calculating device is to ignore over 80% of its functions.
More accurately, we can define a computer as a device that operates upon data, data can be anything like bio-data of applicants when computer is used for listing candidates for recruiting: marks obtained by student in various subjects when used for preparing results: details (name, age, sex, etc.) of passengers when used for making airline or railway reservation; or number of different parameters when used form solving scientific research problems, etc.
Hence, data comes in various shapes and sizes depending upon the type of computer application. A computer can store, process,, and retrieve data as and when desired. The fact that computers process data is so fundamental that many people have started calling is a data processor.
The name data processor is more inclusive because modern computers not only compute in the same usual sense but also perform other functions with data that flows to and form them, for example, data processors may gather data form various incoming sources, merge (proceeds of mixing or putting together) the mall sort (process of arranging in some sequence – ascending) them in the desired order, and finally print them in desired format. Notice that none of these operations involves arithmetic computations in the usual sense but a computer is the most suitable device for performing them.
The activity of processing data using a computer is called data processing. Data processing consists of three sub-activities: capturing input data, manipulating the data and managing output results. As used in data processing, information is data arranged in an order and form that is useful to people receiving it. Hence, data is raw materials used al input to data processing and information is processed data obtained as output of data processing.
In fact, the original objective for inventing a computer was to create a fast calculating machine. However, more than 80% of work done by computers today is of non-mathematical or non-numerical nature. Hence, to define a computer merely as a calculating device is to ignore over 80% of its functions.
More accurately, we can define a computer as a device that operates upon data, data can be anything like bio-data of applicants when computer is used for listing candidates for recruiting: marks obtained by student in various subjects when used for preparing results: details (name, age, sex, etc.) of passengers when used for making airline or railway reservation; or number of different parameters when used form solving scientific research problems, etc.
Hence, data comes in various shapes and sizes depending upon the type of computer application. A computer can store, process,, and retrieve data as and when desired. The fact that computers process data is so fundamental that many people have started calling is a data processor.
The name data processor is more inclusive because modern computers not only compute in the same usual sense but also perform other functions with data that flows to and form them, for example, data processors may gather data form various incoming sources, merge (proceeds of mixing or putting together) the mall sort (process of arranging in some sequence – ascending) them in the desired order, and finally print them in desired format. Notice that none of these operations involves arithmetic computations in the usual sense but a computer is the most suitable device for performing them.
The activity of processing data using a computer is called data processing. Data processing consists of three sub-activities: capturing input data, manipulating the data and managing output results. As used in data processing, information is data arranged in an order and form that is useful to people receiving it. Hence, data is raw materials used al input to data processing and information is processed data obtained as output of data processing.
Evolutions of computers:
MARK-I
In 1973 AD, Howard Aiken, professor of Haward university, developed an automatic calculating machine called Mark-I. It is also called Automatic sequence controlled calculator. It was the first electromechanical computer. It was huge in size and it had 18000 vaccuum tubes to store data in the memory. It used a program to guide it through a long series of calculations.
ABC
ABC is the short form of atanasoft berry computer. It was the first digital computer designed by Dr. John V. Atnasoft and his assistant Clifford Berry in 1942 AD. It used vacuum tubes as a main memory. This computer was designed for solving system of simultaneous lineare equations. This machine was mainly used by military to compute gun firing.
ENIAC
ENIAC stand s for a electronic Numerical Integratot And Calculator. It was the first electronic general purpose computer invented by john w. mauchly and john presper eckertt in 1946 AD. It was 10 feet tall and occupied a space of 30X30 feet it contained 18000 vacuum tubes as main memories it required about 150 kilowatts of power . it could perform many complex arithmetic operations in few seconds .
EDSAC
EDSAC stands for Electronic Delay Storage Automatic Computer. It was the first operational stored program computer. It was invented by mauxice Wilkes at Cambridge University, in 1949 AD. Itr contained 3000 vaccum tuves and it required 30 kilowatts of elecdtric power. In thies computer programs were input using paper tape and output results were printed on a teletype page printer.
UNIVAC
UNIVAC –I stands for universal Automatic Computers. It was developed by John Mauchly J.P. Eckert in 1951 AD. It was the first general purpose electronic digital Computer. This computer consisted of magnetic tape for data input and output. It had 10,000 vacuum tubes. This computer was used for data processing till 1963. in the USA…
EDVAC
EDVAC stands for electronic discrete variable automatic computer. it was designed by more school personnel and the ballistics research laboratory of the us army in 1952 AD. It was able to store programs. This concept was introduced by a Hungarian mathematician john von Newmann.
Over the centuries the development of computing and calculating have been changed dramatically .in this way. The ancient abacus has now taken the form of modern PCs, laptop and palmtops. The computer science is still in never stopping progress….
In 1973 AD, Howard Aiken, professor of Haward university, developed an automatic calculating machine called Mark-I. It is also called Automatic sequence controlled calculator. It was the first electromechanical computer. It was huge in size and it had 18000 vaccuum tubes to store data in the memory. It used a program to guide it through a long series of calculations.
ABC
ABC is the short form of atanasoft berry computer. It was the first digital computer designed by Dr. John V. Atnasoft and his assistant Clifford Berry in 1942 AD. It used vacuum tubes as a main memory. This computer was designed for solving system of simultaneous lineare equations. This machine was mainly used by military to compute gun firing.
ENIAC
ENIAC stand s for a electronic Numerical Integratot And Calculator. It was the first electronic general purpose computer invented by john w. mauchly and john presper eckertt in 1946 AD. It was 10 feet tall and occupied a space of 30X30 feet it contained 18000 vacuum tubes as main memories it required about 150 kilowatts of power . it could perform many complex arithmetic operations in few seconds .
EDSAC
EDSAC stands for Electronic Delay Storage Automatic Computer. It was the first operational stored program computer. It was invented by mauxice Wilkes at Cambridge University, in 1949 AD. Itr contained 3000 vaccum tuves and it required 30 kilowatts of elecdtric power. In thies computer programs were input using paper tape and output results were printed on a teletype page printer.
UNIVAC
UNIVAC –I stands for universal Automatic Computers. It was developed by John Mauchly J.P. Eckert in 1951 AD. It was the first general purpose electronic digital Computer. This computer consisted of magnetic tape for data input and output. It had 10,000 vacuum tubes. This computer was used for data processing till 1963. in the USA…
EDVAC
EDVAC stands for electronic discrete variable automatic computer. it was designed by more school personnel and the ballistics research laboratory of the us army in 1952 AD. It was able to store programs. This concept was introduced by a Hungarian mathematician john von Newmann.
Over the centuries the development of computing and calculating have been changed dramatically .in this way. The ancient abacus has now taken the form of modern PCs, laptop and palmtops. The computer science is still in never stopping progress….
Application of Computer
1. Business:
Computers are the part of the modern society. Modern business cannot survive without computers. In business computers are used to write letters keep employee records, communicate with the co-workers, prepare budgets and perform many other functions.
2. Medicine and Health Care:-
Computers are extensively used in medicine; it is used for diagnosing disease, monitoring the condition of patients and keeping the necessary records.
Many innovative medical applications use small, special-purpose computer. For example, pacemakers are computers that operate within the human body and help to maintain heart beat.
Also, laboratory tests such as X-RAY, CT-SCAN etc. are performed by computers.
3. Education:-
Computers have bought revolution in the field of education. Now computers are used in school and colleges by students, teachers and many others people use computers in library to read magazines and journals from the computer terminal rather than searching the shelves for paper originals..
Teachers use computers as a presentation tool, to explain difficult topics more clearly and easily to their students.
Students use computers to develop their computer projects and to do their mathematical problems.
Computer assisted learning (CAL) is used by students to improve their knowledge of any subjects
4. Space Technology:
It would be impossible to explore outer space without computers. Computers are used to accurate calculations for the spacecraft journey to moon, mars etc. the computer is also used to control the artifartificial satellites to know the weather patterns I earth. Now days the actual damage due to flood, earthquake, etc in particular area of earth is analyzed using satellite pictures.
5. Engineering:-
Engineers use computers to design the model of machines, vehicles, bridges, buildings etc. the design made with computers is more accurate and flexible than the design drawn with paper and pencil.
The design of complex structures such as aero planes, satellites etc. are almost impossible without computers.
6. Aviation:-
The computer is highly used in aviation. Modern aircrafts include sophisticated computerized instruments so that it can communicate with the ground airport stations; identify the status of its parts, fuel and available location in the atmosphere.
Thus. The use of computer has increased security in aviation.
7. Music and Entertainment:-
Computers have become a helpful tool for musicians. It helps them to create various electronic notes. Also the notes can be converted to music graphs. The composer can create the music of many musical instruments using a special keyboard called MIDI keyboard.
Computer games are the means of entertainment for people of all ages. Computers are heavily used in entertainment industry i.e. television, theater, films etc.
Films use special visual effects to make the content real. These effects are possible using computers. Computers have also improved cartooning and animations.
8. The Military:-
Military or defense services use computers massively. The actual development of computers is due to military. In 1964, ENIAC was created for the U.S. army. They used ENIAC for calculating accurate targets of missiles
Now, military uses more advanced computer technology. They use computers so o spy the enemy secrets such as enemy location, enemy numbers and their amount of weapons. They also use a special type of missile called “Smart Bomb” which embeds computer within it.
Computers are the part of the modern society. Modern business cannot survive without computers. In business computers are used to write letters keep employee records, communicate with the co-workers, prepare budgets and perform many other functions.
2. Medicine and Health Care:-
Computers are extensively used in medicine; it is used for diagnosing disease, monitoring the condition of patients and keeping the necessary records.
Many innovative medical applications use small, special-purpose computer. For example, pacemakers are computers that operate within the human body and help to maintain heart beat.
Also, laboratory tests such as X-RAY, CT-SCAN etc. are performed by computers.
3. Education:-
Computers have bought revolution in the field of education. Now computers are used in school and colleges by students, teachers and many others people use computers in library to read magazines and journals from the computer terminal rather than searching the shelves for paper originals..
Teachers use computers as a presentation tool, to explain difficult topics more clearly and easily to their students.
Students use computers to develop their computer projects and to do their mathematical problems.
Computer assisted learning (CAL) is used by students to improve their knowledge of any subjects
4. Space Technology:
It would be impossible to explore outer space without computers. Computers are used to accurate calculations for the spacecraft journey to moon, mars etc. the computer is also used to control the artifartificial satellites to know the weather patterns I earth. Now days the actual damage due to flood, earthquake, etc in particular area of earth is analyzed using satellite pictures.
5. Engineering:-
Engineers use computers to design the model of machines, vehicles, bridges, buildings etc. the design made with computers is more accurate and flexible than the design drawn with paper and pencil.
The design of complex structures such as aero planes, satellites etc. are almost impossible without computers.
6. Aviation:-
The computer is highly used in aviation. Modern aircrafts include sophisticated computerized instruments so that it can communicate with the ground airport stations; identify the status of its parts, fuel and available location in the atmosphere.
Thus. The use of computer has increased security in aviation.
7. Music and Entertainment:-
Computers have become a helpful tool for musicians. It helps them to create various electronic notes. Also the notes can be converted to music graphs. The composer can create the music of many musical instruments using a special keyboard called MIDI keyboard.
Computer games are the means of entertainment for people of all ages. Computers are heavily used in entertainment industry i.e. television, theater, films etc.
Films use special visual effects to make the content real. These effects are possible using computers. Computers have also improved cartooning and animations.
8. The Military:-
Military or defense services use computers massively. The actual development of computers is due to military. In 1964, ENIAC was created for the U.S. army. They used ENIAC for calculating accurate targets of missiles
Now, military uses more advanced computer technology. They use computers so o spy the enemy secrets such as enemy location, enemy numbers and their amount of weapons. They also use a special type of missile called “Smart Bomb” which embeds computer within it.
Basic organization of computer system
A computer is an electronic machine that converts the raw data into useful information. In short, we can say that a computer is a data processing machine.
The computer system works in the principle of IPO:-
1. INPUT (I):-the computer accepts data and instructions from the user. The input function is performed by input devices. Such as keyboard, mouse, microphone etc.
2. PROCESSING (P):- the computer processes the data as per the given instruction. It is performed by the central processing unit (CPU).
3. OUTPUT (O):- the computer produces the result of processing. It is done through output devices such as monitor, speakers, printer, etc.
4. Storage:- the computer stores the data and information for temporary purpose as well as for future use. It is performed by storage devices such as RAM, Hard Disk, and Optical Disk etc.
Fig: - Basic Operation of Computer System.
The computer system works in the principle of IPO:-
1. INPUT (I):-the computer accepts data and instructions from the user. The input function is performed by input devices. Such as keyboard, mouse, microphone etc.
2. PROCESSING (P):- the computer processes the data as per the given instruction. It is performed by the central processing unit (CPU).
3. OUTPUT (O):- the computer produces the result of processing. It is done through output devices such as monitor, speakers, printer, etc.
4. Storage:- the computer stores the data and information for temporary purpose as well as for future use. It is performed by storage devices such as RAM, Hard Disk, and Optical Disk etc.
Fig: - Basic Operation of Computer System.
Generation of Computer
First generation
Characteristic features of first-generation computer are as follows:
1. They were the fastest calculating device of their time.
2. they were too bulky in size, requiring large room for installation
3. They used thousand of vacuum tubes that emitted large amount of great and burnt out frequently. Hence, the rooms/areas in which these computers were located had to be properly air-conditioned.
4. Each vacuum tube consumed about half a watt of power. since a computer typically used more than ten thousand vacuum tube, power consumption of these computer was very high
Second Generation:-
John Bardeen, willian Shockley, and walter brattain invented a new electronic device called transistor at Bell laboratories in 1947. Transistors soon proved to be a better electronic switching device than vacuum tubes due to their following properties:-
1. They were more rugged and easier to handle than tubes since they were made of germanium semiconductor material rather than glass.
2. They were highly reliable as compared to tubes since that had no parts like a filament that could burn out.
3. They could switch much faster (almost ten times faster) than tubes. Hence, switching circuits made of transistors could operate much faster than their counterparts made of tubes.
4. They consumed almost one –tenth the power consumed by a tube.
5. They were much smaller than tubes.
Characteristics features of second generation:-
1. They were more than ten times faster than the first-generation computers.
2. They were smaller than first-generation computers.
3. They consumed less power and dissipated less heat than the first-generation computers.
4. They were more reliable and less prone to hardware failures than the first- generation computers.
Third Generation:-
Characteristics features of third generation computers are as follows:-
1. They were more powerful tan second-generation computrers. They were capable of performing about 1 million instructions per second.
2. They were smaller than second-generation computers requiring smaller space.
3. They consumed less power and dissipated less heat than second-generation computers. The rooms/areas in which third generation computers were located still required to be properly air-conditioned.
4. They were more reliable and less prone to hardware failure than second –generation computers requiring lower maintenance cost.
5. They had faster and larger primary and secondary storage as compared to second-generation computers.
6. They were general- purposed machines suitable for both scientific and commercial applications.
Fourth Generation:-
Characteristics features of fourth generation computers are as follows:-
1. PCs were smaller and cheaper than mainframes or minicomputers of third generation.
2. Although the fourth-generation mainframes require proper air-conditioning of the rooms/area in which they were located, no air-conditioning was required for PCs.
3. They consumed less power than third generation computers.
4. They were general purposed machines.
5. Graphical user interface (GUI) enabled new users to quickly learn how to use computers.
Fifth Generation:-
Characteristics features of fourth generation computers are as follows:-
1. Portable PCs (called notebook computers) are much smaller and handy than PCs of fourth generation allowing users to use computing facility even while traveling.
2. Fifth-generation desktop PCs and workstations are several times more powerful than PCs of fourth generation.
3. They consume less power than their predecessors do.
4. They are more reliable and less prone to hardware failures than their predecessors were. Requiring negligible maintenance cost.
5. They have faster and larger primary and secondary storage as compared to their predecessors.
6. They are general purposed machines.
Characteristic features of first-generation computer are as follows:
1. They were the fastest calculating device of their time.
2. they were too bulky in size, requiring large room for installation
3. They used thousand of vacuum tubes that emitted large amount of great and burnt out frequently. Hence, the rooms/areas in which these computers were located had to be properly air-conditioned.
4. Each vacuum tube consumed about half a watt of power. since a computer typically used more than ten thousand vacuum tube, power consumption of these computer was very high
Second Generation:-
John Bardeen, willian Shockley, and walter brattain invented a new electronic device called transistor at Bell laboratories in 1947. Transistors soon proved to be a better electronic switching device than vacuum tubes due to their following properties:-
1. They were more rugged and easier to handle than tubes since they were made of germanium semiconductor material rather than glass.
2. They were highly reliable as compared to tubes since that had no parts like a filament that could burn out.
3. They could switch much faster (almost ten times faster) than tubes. Hence, switching circuits made of transistors could operate much faster than their counterparts made of tubes.
4. They consumed almost one –tenth the power consumed by a tube.
5. They were much smaller than tubes.
Characteristics features of second generation:-
1. They were more than ten times faster than the first-generation computers.
2. They were smaller than first-generation computers.
3. They consumed less power and dissipated less heat than the first-generation computers.
4. They were more reliable and less prone to hardware failures than the first- generation computers.
Third Generation:-
Characteristics features of third generation computers are as follows:-
1. They were more powerful tan second-generation computrers. They were capable of performing about 1 million instructions per second.
2. They were smaller than second-generation computers requiring smaller space.
3. They consumed less power and dissipated less heat than second-generation computers. The rooms/areas in which third generation computers were located still required to be properly air-conditioned.
4. They were more reliable and less prone to hardware failure than second –generation computers requiring lower maintenance cost.
5. They had faster and larger primary and secondary storage as compared to second-generation computers.
6. They were general- purposed machines suitable for both scientific and commercial applications.
Fourth Generation:-
Characteristics features of fourth generation computers are as follows:-
1. PCs were smaller and cheaper than mainframes or minicomputers of third generation.
2. Although the fourth-generation mainframes require proper air-conditioning of the rooms/area in which they were located, no air-conditioning was required for PCs.
3. They consumed less power than third generation computers.
4. They were general purposed machines.
5. Graphical user interface (GUI) enabled new users to quickly learn how to use computers.
Fifth Generation:-
Characteristics features of fourth generation computers are as follows:-
1. Portable PCs (called notebook computers) are much smaller and handy than PCs of fourth generation allowing users to use computing facility even while traveling.
2. Fifth-generation desktop PCs and workstations are several times more powerful than PCs of fourth generation.
3. They consume less power than their predecessors do.
4. They are more reliable and less prone to hardware failures than their predecessors were. Requiring negligible maintenance cost.
5. They have faster and larger primary and secondary storage as compared to their predecessors.
6. They are general purposed machines.
Characteristics of computers
Some important characteristics of computer are listed below:
1. Automatic: an automatic machine works by itself without human intervention. Computers are automatic machines because once started on a job. They carry out the job (normally without any human assistance) until it is finished. However, computers being machines cannot start themselves and cannot go out and find their own problems and solutions we need to instruct a computer using coded instructions that specify exactly how it will do a particular job. Some of the other characteristics of computer (such as speed and accuracy) are because they are automatic and work on a problem without any human intervention.
2. Speed: a computer is very facts device. It can perform in a few seconds, the amount of work that a human being can do in an entire year- if he/she worked day and night and did nothing else. In other words. A computer can do in a few minutes what would take a man his entire lifetime.
3. Accuracy: in addition to being very fast, computers are very accurate. Accuracy of a computer is consistently high and the degree of its accuracy depends upon its design. A computer performs every calculation with the same accuracy.
4. Diligence: unlike human beings a computer is free from monotony, tiredness, and lack of concentration. It can continuously work for hours without creating any error and without grumbling. Hence, computer scorer over human beings in doing routing type of jobs that requires great accuracy. If ten million calculations have to be performed, a computer will perform the last one with exactly the same accuracy and speed as the first one.
5. Versatility: versatility is one of the most wonderful things about a computer. One moment it is preparing results of an examination, next moment it is busy preparing electricity bills and in between, it may be helping an office secretary to trace an important letter4 in seconds.
6. Power of remembering: as a human being acquires now knowledge, his/her brain subconsciously selects what it feels to be important and worth retaining in memory
7. No I.Q.: a computer is not a magical device. Its possesses no intelligence of its own. Its I.Q. is zero.
8. No feelings: computers are devoid of emotions. They have no feelings and no instincts because they are machine.
1. Automatic: an automatic machine works by itself without human intervention. Computers are automatic machines because once started on a job. They carry out the job (normally without any human assistance) until it is finished. However, computers being machines cannot start themselves and cannot go out and find their own problems and solutions we need to instruct a computer using coded instructions that specify exactly how it will do a particular job. Some of the other characteristics of computer (such as speed and accuracy) are because they are automatic and work on a problem without any human intervention.
2. Speed: a computer is very facts device. It can perform in a few seconds, the amount of work that a human being can do in an entire year- if he/she worked day and night and did nothing else. In other words. A computer can do in a few minutes what would take a man his entire lifetime.
3. Accuracy: in addition to being very fast, computers are very accurate. Accuracy of a computer is consistently high and the degree of its accuracy depends upon its design. A computer performs every calculation with the same accuracy.
4. Diligence: unlike human beings a computer is free from monotony, tiredness, and lack of concentration. It can continuously work for hours without creating any error and without grumbling. Hence, computer scorer over human beings in doing routing type of jobs that requires great accuracy. If ten million calculations have to be performed, a computer will perform the last one with exactly the same accuracy and speed as the first one.
5. Versatility: versatility is one of the most wonderful things about a computer. One moment it is preparing results of an examination, next moment it is busy preparing electricity bills and in between, it may be helping an office secretary to trace an important letter4 in seconds.
6. Power of remembering: as a human being acquires now knowledge, his/her brain subconsciously selects what it feels to be important and worth retaining in memory
7. No I.Q.: a computer is not a magical device. Its possesses no intelligence of its own. Its I.Q. is zero.
8. No feelings: computers are devoid of emotions. They have no feelings and no instincts because they are machine.
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