Computer Fundamental(BCA)

CHAPTER-1 

(COMPUTER OVERVIEW)

WHAT IS A COMPUTER?

A computer is an electronic device that manipulates information, or "data." It has the ability to store, retrieve, and process data. You can use a computer to type documents, send email, and browse the internet. You can also use it to handle spreadsheets, accounting, database management, presentations, games, and more.

FUNCTIONALITIES OF A COMPUTER

Any digital computer carries out five functions in gross terms:

• Takes data as input.
• Stores the data/instructions in its memory and can use them when required.
• Process the data and convert it into useful information.
• Output the information.
• Control all the above four steps.

DEFINITION

Computer System is an electronic data processing device which does the following:

• Accept and store an input data.
• Process the data input.
• And output the processed data in required format.

ADVANTAGES

Following list demonstrates the advantages of Computers in today's arena.

HIGH SPEED

• Computer is a very fast device.
• It is capable of performing addition of very big data.
• The computer has units of speed in microsecond, nanosecond and even the pico second.
• It can perform millions of calculations in a few seconds as compared to man who can spend many months for doing the same task.

ACCURACY

• In addition to being very fast, computers are very accurate.
• The computer has performed calculations 100% error free.
• Computers perform all jobs with 100% accuracy.

STORAGE CAPABILITY

• Memory is a very important characteristic of computers.
• The computer has much more storage capacity than human beings.
• It can store large amount of data.
• It can store any type of data such as images, videos, text, audio and any other type.

DILIGENCE

• Unlike human beings, a computer is free from monotony, tiredness and lack of concentration.
• It can work continuously without creating any error and boredom.
• It can do repeated work with same speed and accuracy.

VERSATILITY

• A computer is a very versatile machine.
• A computer is very flexible in performing the jobs to be done.
• This machine can be used to solve the problems relating to various different fields.
• At one instant, it may be solving a complex scientific problem and the very next moment it may be playing a card game.

RELIABILITY

• A computer is a reliable machine.
• Modern electronic components have failure free long lives.
• Computers are designed to make maintenance easy.

AUTOMATION

• Computer is a automatic machine.
• Automation means ability to perform the task automatically.
• Once a program is given to computer i.e stored in computer memory, the program and instruction can control the program execution without human interaction.

REDUCTION IN PAPER WORK

• The use of computers for data processing in an organization leads to reduction in paper work and speeds up the process.
• As data in electronic files can be retrieved as and when required, the problem of maintenance of large number of files gets reduced.

REDUCTION IN COST

• Though the initial investment for installing a computer is high but it substantially reduces the cost of each of its transaction.

DISADVANTAGES OF COMPUTER

Following list demonstrates the disadvantages of Computers in today's arena.

No I.Q

• A computer is a machine and has no intelligence of its own to perform any task.
• Each and every instruction has to be given to computer.
• A computer cannot take any decision on its own.

DEPENDENCY

• It can perform function as instructed by user. So it is fully dependent on human being.

ENVIRONMENT

• The operating environment of computer should be dust free and suitable to it.

NO FEELING

• Computer has no feeling or emotions.
• It cannot make Judgment based on feeling, taste, experience and knowledge unlike a human being.

APPLICATION OF COMPUTERS

Computers have proliferated into various areas of our lives. For a user, computer is a tool that provides the desired information, whenever needed. You may use computer to get information about the reservation of tickets (railways, airplanes and cinema halls), books in a library, medical history of a person, a place in a map, or the dictionary meaning of a word. The information may be presented to you in the form of text, images, video clips, etc.

Some of the application areas of the computer are listed below—

·         Education Computers are extensively used, as a tool and as an aid, for imparting education. Educators use computers to prepare notes and presentations of their lectures. Computers are used to develop computer-based training packages, to provide distance education using the e-learning software, and to conduct online examinations. Researchers use computers to get easy access to conference and journal details and to get global access to the research material.

·         Entertainment Computers have had a major impact on the entertainment industry. The user can download and view movies, play games, chat, book tickets for cinema halls, use multimedia for making movies, incorporate visual and sound effects using computers, etc. The users can also listen to music, download and share music, create music using computers, etc.

·         Sports A computer can be used to watch a game, view the scores, improve the game, play games (like chess, etc.) and create games. They are also used for the purposes of training players.

·         Advertising Computer is a powerful advertising media. Advertisement can be displayed on different websites, electronic-mails can be sent and reviews of a product by different customers can be posted. Computers are also used to create an advertisement using the visual and the sound effects. For the advertisers, computer is a medium via which the advertisements can be viewed globally. Web advertising has become a significant factor in the marketing plans of almost all companies. In fact, the business model of Google is mainly dependent on web advertising for generating revenues.

·         Medicine Medical researchers and practitioners use computers to access information about the advances in medical research or to take opinion of doctors globally. The medical history of patients is stored in the computers. Computers are also an integral part of various kinds of sophisticated medical equipments like ultrasound machine, CAT scan machine, MRI scan machine, etc. Computers also provide assistance to the medical surgeons during critical surgery operations like laparoscopic operations, etc.

·         Science and Engineering Scientists and engineers use computers for performing complex scientific calculations, for designing and making drawings (CAD/CAM applications) and also for simulating and testing the designs. Computers are used for storing the complex data, performing complex calculations and for visualizing 3-dimensional objects. Complex scientific applications like the launch of the rockets, space exploration, etc., are not possible without the computers.

·         Government The government uses computers to manage its own operations and also for e-governance. The websites of the different government departments provide information to the users. Computers are used for the filing of income tax return, paying taxes, online submission of water and electricity bills, for the access of land record details, etc. The police department uses computers to search for criminals using fingerprint matching, etc.

·         Home Computers have now become an integral part of home equipment. At home, people use computers to play games, to maintain the home accounts, for communicating with friends and relatives via Internet, for paying bills, for education and learning, etc. Microprocessors are embedded in house hold utilities like, washing machines, TVs, food processors, home theatres, security devices, etc.

THE COMPUTER SYSTEM

Computer is an electronic device that accepts data as input, processes the input data by performing mathematical and logical operations on it, and gives the desired output. The computer system consists of four parts—(1) Hardware, (2) Software, (3) Data, and (4) Users.

Hardware consists of the mechanical parts that make up the computer as a machine. The hardware consists of physical devices of the computer. The devices are required for input, output, storage and processing of the data. Keyboard, monitor, hard disk drive, floppy disk drive, printer, processor and motherboard are some of the hardware devices.

Software is a set of instructions that tells the computer about the tasks to be performed and how these tasks are to be performed. Program is a set of instructions, written in a language understood by the computer, to perform a specific task. A set of programs and documents are collectively called software. The hardware of the computer system cannot perform any task on its own. The hardware needs to be instructed about the task to be performed. Software instructs the computer about the task to be performed. The hardware carries out these tasks. Different software can be loaded on the same hardware to perform different kinds of tasks.

Data are isolated values or raw facts, which by themselves have no much significance. For example, the data like 29, January, and 1994 just represent values. The data is provided as input to the computer, which is processed to generate some meaningful information. For example, 29, January and 1994 are processed by the computer to give the date of birth of a person.

Users are people who write computer programs or interact with the computer. They are also known as skinware, liveware, humanware or peopleware. Programmers, data entry operators, system analyst and computer hardware engineers fall into this category.

The Input-Process-Output Concept

A computer is an electronic device that (1) accepts data, (2) processes data, (3) generates output, and (4) stores data. The concept of generating output information from the input data is also referred to as input-process-output concept.

The input-process-output concept of the computer is explained as follows—

·         Input The computer accepts input data from the user via an input device like keyboard. The input data can be characters, word, text, sound, images, document, etc.

·         Process The computer processes the input data. For this, it performs some actions on the data by using the instructions or program given by the user of the data. The action could be an arithmetic or logic calculation, editing, modifying a document, etc. During processing, the data, instructions and the output are stored temporarily in the computer’s main memory.

·         Output The output is the result generated after the processing of data. The output may be in the form of text, sound, image, document, etc. The computer may display the output on a monitor, send output to the printer for printing, play the output, etc.

·         Storage The input data, instructions and output are stored permanently in the secondary storage devices like disk or tape. The stored data can be retrieved later, whenever needed.

SELF ASSIGNMENT

     I.            What is Computer?

  II.            Describe the functionality of Computer.

III.            Write the drawbacks of computer.

IV.            Distinguish between bit and byte.

  V.            Fill in the blanks with appropriate answers:

a)      The second generation computers contained _____________ in place of vacuum tubes.

b)      _________ computers aim to solve highly complex problems which require reasonable intelligence and expertise when solved by people.

c)      CPU stands for _____________________________________

d)     MICR stands for________________________________________.

e)      __________ is a memory chip on which programs can be stored.

 

CHAPTER-2 (GENERATION OF COMPUTER)

COMPUTER GENERATIONS

Generation in computer terminology is a change in technology a computer is/was being used. Initially, the generation term was used to distinguish between varying hardware technologies. But nowadays, generation includes both hardware and software, which together make up an entire computer system.

There are totally five computer generations known till date. Each generation has been discussed in detail along with their time period, characteristics. We've used approximate dates against each generation which are normally accepted.

Following are the main five generations of computers

SNO	GENERATION	PERIOD	DESCRIPTION
1	FIRST	1946-1959	VACUUM  TUBE BASED
2	SECOND	1959-1965	TRANSISTOR BASED
3	THIRD	1965-1971	INTEGRATED CIRCUIT
4	FOURTH	1971-1980	VLSI MICRO PROCESSOR
5	FIFTH	1980-ON WARDS	ULSI MICOPROCESSOR

FIRST GENERATION

The period of first generation was 1946-1959.

First generation of computer started with using vacuum tubes as the basic components for memory and circuitry for CPU(Central Processing Unit). These tubes like electric bulbs produced a lot of heat and were prone to frequent fusing of the installations, therefore, were very expensive and could be afforded only by very large organisations.

In this generation mainly batch processing operating system were used. In this generation Punched cards, Paper tape, Magnetic tape Input & Output device were used.

There were Machine code and electric wired board languages used.

The main features of First Generation are:

• Vacuum tube technology
• Unreliable
• Supported Machine language only
• Very costly
• Generate lot of heat
• Slow Input /Output device
• Huge size
• Need of A.C.
• Non portable
• Consumed lot of electricity

Some computer of this generation was:

• ENIAC
• EDVAC
• UNIVAC
• IBM-701
• IBM-650

SECOND GENERATION

The period of second generation was 1959-1965.

This generation using the transistor were cheaper, consumed less power, more compact in size, more reliable and faster than the first generation machines made of vacuum tubes. In this generation, magnetic cores were used as primary memory and magnetic tape and magnetic disks as secondary storage devices.

In this generation assembly language and high level programming language like FORTRAN, COBOL was used.

There was Batch processing and Multiprogramming Operating system used.

The main features of Second Generation are:

• Use of transistors
• Reliable as compared to First generation computers
• Smaller size as compared to First generation computers
• Generate less heat as compared to First generation computers
• Consumed less electricity as compared to First generation computers
• Faster than first generation computers
• Still very costly
• A.C. needed
• Support machine and assembly languages

Some computer of this generation were:

• IBM 1620
• IBM 7094
• CDC 1604
• CDC 3600
• UNIVAC 1108

THIRD GENERATION

The period of third generation was 1965-1971.

The third generation of computer is marked by the use of Integrated Circuits (IC's) in place of transistors. A single I.C has many transistors, resistors and capacitors along with the associated circuitry. The I.C was invented by Jack Kilby. This development made computers smaller in size, reliable and efficient.

In this generation Remote processing, Time-sharing, Real-time, Multi-programming Operating System were used.

High level language (FORTRAN-II TO IV, COBOL, PASCAL PL/1, BASIC, ALGOL-68 etc.) were used during this generation.

The main features of Third Generation are:

• IC used
• More reliable
• Smaller size
• Generate less heat
• Faster
• Lesser maintenance
• Still costly
• A.C needed
• Consumed lesser electricity
• Support high level language

Some computer of this generation was:

• IBM-360 series
• Honeywell-6000 series
• PDP(Personal Data Processor)
• IBM-370/168
• TDC-316

FOURTH GENERATION

The period of Fourth Generation was 1971-1980.

The fourth generation of computers is marked by the use of Very Large Scale Integrated (VLSI) circuits. VLSI circuits having about 5000 transistors and other circuit elements and their associated circuits on a single chip made it possible to have microcomputers of fourth generation. Fourth Generation computers became more powerful, compact, reliable, and affordable. As a result, it gave rise to personal computer (PC) revolution.

In this generation Time sharing, Real time, Networks, Distributed Operating System were used.

All the Higher level languages like C and C++, DBASE etc. were used in this generation.

The main features of Fourth Generation are:

• VLSI technology used
• Very cheap
• Portable and reliable
• Use of PC's
• Very small size
• Pipeline processing
• No A.C. needed
• Concept of internet was introduced
• Great developments in the fields of networks
• Computers became easily available

Some computer of this generation were:

• DEC 10
• STAR 1000
• PDP 11
• CRAY-1(Super Computer)
• CRAY-X-MP(Super Computer)

FIFTH GENERATION

The period of Fifth Generation is 1980-till date.

In the fifth generation, the VLSI technology became ULSI (Ultra Large Scale Integration) technology, resulting in the production of microprocessor chips having ten million electronic components.

This generation is based on parallel processing hardware and AI (Artificial Intelligence) software.

AI is an emerging branch in computer science, which interprets means and method of making computers think like human beings.

All the Higher level languages like C and C++, Java, .Net etc. are used in this generation.

AI includes:

• Robotics
• Neural networks
• Game Playing
• Development of expert systems to make decisions in real life situations.
• Natural language understanding and generation.

The main features of Fifth Generation are:

• ULSI technology
• Development of true artificial intelligence
• Development of Natural language processing
• Advancement in Parallel Processing
• Advancement in Superconductor technology
• More user friendly interfaces with multimedia features
• Availability of very powerful and compact computers at cheaper rates

Some computer types of this generation are:

• Desktop
• Laptop
• NoteBook
• UltraBook
• ChromeBook

SELF ASSIGNMENT

1.      Why is computer known as data processor?

2.      In how many generations is the evaluation of computer is divided?

3.      What is VLSIC?

4.      Why did the size of computer get reduced in third generation computer?

5.      Distinguish between Micro Computer and Mainframe computer.

6.      Fill in the blanks with appropriate answers:

a.       The name of first digital computer is_______________

b.         A device that controls the movement of the cursor or pointer on a display screen is called       the ______________________ 

c.       An example of an impact printer is________________.

d.      ___________Is the feature that causes the word processor to force all text to fit within the defined margin.

e.       In a spreadsheet, the interaction of a row and column is called_________.