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CHAPTER – 1 INTRODUCTION TO COMPUTERS

1. INTRODUCTION Computer is an advanced electronic device that takes raw data as input from the

user and processes it under the control of set of instructions (called program), gives the

result (output), and saves it for the future use. Data is the raw or unorganized facts can be

in the form of text, graphics, audio or video. Information is the meaningful data that is

relevant, accurate, up-to-date and can be used to make decisions. Information processing

is converting data into information.

2. HOW COMPUTERS WORK Any digital computer carries out five functions in gross terms:

• Takes data as input.

• Stores the data/instructions in its memory and use them when required.

• Processes the data and converts it into useful information.

• Generates the output

• Controls all the above four steps.

Figure 1.1: Functions of Computer

3. 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 calculation of very large amount of data.

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• The computer has units of speed in microsecond, nanosecond, and even the picosecond.

• It can perform millions of calculations in a few seconds as compared to man who will spend many months for doing the same task.

Accuracy

• In addition to being very fast, computers are very accurate.

• The calculations are 100% error free.

• Computers perform all jobs with 100% accuracy provided that correct input has been given.

Storage Capability

• Memory is a very important characteristic of computers.

• A 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 many others.

Diligence

• Unlike human beings, a computer is free from monotony, tiredness and lack of concentration.

• It can work continuously without 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 related to various fields.

• At one instance, 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 long lives.

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• Computers are designed to make maintenance easy.

Automation

• Computer is an automatic machine.

• Automation means ability to perform the given 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 results in speeding up a process.

• As data in electronic files can be retrieved as and when required, the problem of maintenance of large number of paper 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.

4. DISADVANTAGES

• A computer is a machine that has no intelligence to perform any task.

• Each instruction has to be given to computer.

• A computer cannot take any decision on its own.

5. FUNDAMENTALS OF COMPUTER SYSTEMS

A Computer is therefore a mixture of physical, tangible(touchable) things like

keyboards, mouse, monitors, internal circuits and communication media referred to as

HARDWARE and intangible things like stored programs referred to as SOFTWARE.

Using electrical impulses, the two are connected and communicate with each other. Hardware and Software have a symbiotic relationship, this means that without software hardware

is very limited; and without hardware, software wouldn't be able to run at all. They need each

other to fulfill their potential.

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1. Hardware - Physical components that make up a computer system

Figure 1.2: Hardware of a Modern personal computer

2. Software - Computer programs and related data that provide the instructions for telling computer hardware what to do and how to do it.

Figure 1.3: Relationship between Hardware and Software

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6. APPLICATIONS OF COMPUTER 1. Business

A computer has high speed of calculation, diligence, accuracy, reliability, or versatility which made it an integrated part in all business organizations.

Figure 1.4: Business Application Computer is used in business organizations for:

• Payroll calculations

• Budgeting

• Sales analysis

• Financial forecasting

• Managing employees database

• Maintenance of stocks etc.

2. Banking

Today banking is almost totally dependent on computer.

Banks provide following facilities:

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• Banks provide online accounting facility, which includes current balances, deposits, overdrafts, interest charges, shares, and trustee records.

• ATM machines are making it even easier for customers to deal with banks.

Figure 1.5: Banking Application

3. Insurance Insurance companies are keeping all records up-to-date with the help of computers. The insurance companies, finance houses and stock broking firms are widely using computers for their concerns. Insurance companies are maintaining a database of all clients with information showing

• procedure to continue with policies

• starting date of the policies

• next due installment of a policy

• maturity date

• interests due

• survival benefits

• bonus

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Figure 1.6: Insurance Application

4. Education

The computer has provided a lot of facilities in the education system.

• The computer provides a tool in the education system known as CBE (Computer Based Education).

• CBE involves control, delivery, and evaluation of learning.

• The computer education is rapidly increasing the graph of number of computer students.

• There are number of methods in which educational institutions can use computer to educate the students.

• It is used to prepare a database about performance of a student and analysis is carried out on this basis.

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Figure 1.7: Education Application

5. Marketing In marketing, uses of computer are following:

• Advertising - With computers, advertising professionals create art and graphics, write and revise copy, and print and disseminate ads with the goal of selling more products.

• At Home Shopping - Home shopping has been made possible through use of computerized catalogues that provide access to product information and permit direct entry of orders to be filled by the customers.

Figure 1.8: Marketing Application

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6. Health Care Computers have become important part in hospitals, labs, and dispensaries. The computers are being used in hospitals to keep the record of patients and medicines. It is also used in scanning and diagnosing different diseases. ECG, EEG, Ultrasounds and CT Scans etc., are also done by computerized machines.

Some major fields of health care in which computers are used are:

• Diagnostic System - Computers are used to collect data and identify cause of illness.

• Lab-diagnostic System - All tests can be done and reports are prepared by computer.

• Patient Monitoring System - These are used to check patient's signs for abnormality such as in Cardiac Arrest, ECG etc.

• Pharma Information System - Computer checks Drug-Labels, Expiry dates, harmful drug’s side effects etc.

• Surgery: Nowadays, computers are also used in performing surgery.

Figure 1.9: Health Care Application

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7. Engineering Design Computers are widely used in engineering purpose.

One of major areas is CAD (Computer aided design). That provides creation and modification of images. Some fields are:

• Structural Engineering - Requires stress and strain analysis for design of Ships, Buildings, Budgets, and Airplanes etc.

• Industrial Engineering - Computers deal with design, implementation and improvement of integrated systems of people, materials and equipments.

• Architectural Engineering - Computers help in planning towns, designing buildings, determining a range of buildings on a site using both 2D and 3D drawings.

Figure 1.10: Engineering Application

8. Military Computers are largely used in defence. Modern tanks, missiles, weapons etc. Military also employs computerized control systems. Some military areas where a computer has been used are:

• Missile Control

• Military Communication

• Military Operation and Planning

• Smart Weapons

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Figure 1.11: Military Application

9. Communication

Communication means to convey a message, an idea, a picture or speech that is

received and understood clearly and correctly by the person for whom it is meant for.

Some main areas in this category are:

• E-mail • Chatting • Usenet • FTP • Telnet • Video-conferencing

Figure 1.12: Computer Communication

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10. Government Computers play an important role in government. Some major fields in this category are:

• Budgets • Sales tax department • Income tax department • Male/Female ratio • Computerization of voters lists • Computerization of driving licensing system • Computerization of PAN card • Weather forecasting

Figure 1.13: Government Application

7. GENERATIONS OF COMPUTER 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 and characteristics. Here approximate dates against each generations have been mentioned which are normally accepted.

Following are the main five generations of computers

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S.N. Generation & Description

1 First Generation: The period of first generation: 1946-1959. Vacuum tube based.

2 Second Generation: The period of second generation: 1959-1965. Transistor based

3 Third Generation: The period of third generation: 1965-1971. Integrated Circuit based.

4 Fourth Generation: The period of fourth generation: 1971-1980. VLSI microprocessor based.

5 Fifth Generation: The period of fifth generation: 1980-onwards. ULSI microprocessor based.

Table 1.1: Generations of Computer 8. TYPES OF COMPUTER Computers can be broadly classified by their speed and computing power.

1. PC (PERSONAL COMPUTER) A PC can be defined as a small, relatively inexpensive computer designed for an individual user. Another name of PC is Microcomputer, because they are based on the microprocessor technology. The first personal computer produced by IBM was called the PC. Businesses use personal computers for word processing, accounting, desktop publishing, and for running spreadsheet and database management applications. At home, the most popular use for personal computers is playing games and surfing Internet.

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Figure 1.14: Personal Computer

Laptop computer: Also known as a notebook; a laptop computer is a portable microcomputers, and is the similar to desktop models in speed, performance and usage. Laptops got their name from the fact that you could rest the computer on top of your lap and work (e.g. during seminars, lecture session, etc.).

Figure 1.15: Laptop Computer

2. WORKSTATION / NETWORK COMPUTERS Workstation is a computer used for engineering applications (CAD/CAM), desktop publishing, software development, and other such types of applications which require a moderate amount of computing power and relatively high quality graphics capabilities.

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Figure 1.16: Workstation

However, workstations are typically linked together to form a computer network

called a local area network, which means that several people, such as staff in an office,

can communicate with each other and share electronic files and data. So they are also

known as Network Computers.

There are two versions of computers used in Workstation.

1. Server:

A large PC-type computer called a Server comes with a large, high-resolution graphics screen, large amount of RAM, more powerful processors, inbuilt network support, multiple hard disk drives, and a graphical user interface. They are called servers because they are providing services to clients for sharing files, data and applications.

2. Client:

This type of workstation comes with or without a disk drive.

Thin-client: A Thin-client is a monitor with a keyboard and a small box which contains the CPU and the Main Memory. Thin-client may not have any hard disks - therefore it is unable to work independently. A thin-client downloads applications and data from the server into its main memory. Then any changes, which are made, will be stored in the server. Sometimes they are referred to us a lean, zero or slim client.

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Figure 1.17: Thin-client computer Fat-Client: They are also be used as stand-alone systems like PC with hard disk and they are typically linked together to form a local-area network. Thick-clients are designed to take their computational roles by themselves, but thin-clients are not. Sometimes they are referred to us thick client.

3. EMBEDDED COMPUTER

The most commonly found and used computer. An embedded computer is a

computer with a specific function found in such things like cars, microwaves, TVs, the

VCR, and other home electronics.

Figure 1.18: Embedded Computer

4. SUPER COMPUTER Supercomputers are one of the fastest computers currently available.

Supercomputers are very expensive and are employed for specialized applications that

require immense amount of mathematical calculations (number crunching). For example,

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weather forecasting, scientific simulations, (animated) graphics, fluid dynamic

calculations, nuclear energy research, electronic design, and analysis of geological data

(e.g. in petrochemical prospecting). This type of computer is found in special offices like

the Pentagon or NASA.

Figure 1.19: Super Computer

S.N Type Specifications

1 PC (Personal Computer)

It is a single user computer system designed with microprocessor technology.

2 Workstation It is also a single user computer system which is similar to personal computer but have more powerful microprocessor and relatively high quality graphics capabilities.

3 Embedded Computers

A computer with a specific function found in such things like cars, microwaves, TVs, the VCR, and other home electronics.

4 Supercomputer It is an extremely fast computer which can execute hundreds of millions of instructions per second.

Table 1.2: Types of Computer

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9. MAJOR COMPONENTS OF COMPUTER All types of computers follow a same basic logical structure and perform the

following basic operations for converting raw input data into information useful to their

users. A computer accepts and then processes input data according to the instructions it is

given. The elements of any sort of processing are INPUT, PROCESSING, STORAGE,

and OUTPUT that can be depicted as shown in the following diagram

PROCESSING INPUT OUTPUT

STORAGE Figure 1.20: Block Diagram of Computer Note: STORAGE means not only secondary storage, storage such as Cache memory and

registers inside CPU, primary storage (RAM and ROM) inside System Unit also.

10. COMPUTER SCIENCE AS DISCIPLINE

Computer science is a discipline that spans theory and practice. It requires

thinking both in abstract terms and in concrete terms. The practical side of computing can

Input Unit Output Unit

System Unit

CPU

Primary Storage

RAM and ROM

Secondary Storage

Control Unit

ALU

Cache Memory

Registers

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be seen everywhere. Nowadays, practically everyone is a computer user, and many

people are even computer programmers. Getting computers to do what you want them to

do requires intensive hands-on experience. But computer science can be seen on a higher

level, as a science of problem solving. Computer scientists must be adept at modeling and

analyzing problems. They must also be able to design solutions and verify that they are

correct. Problem solving requires precision, creativity, and careful reasoning. Computer science also has strong connections to other disciplines. Many

problems in science, engineering, health care, business, and other areas can be solved

effectively with computers, but finding a solution requires both computer science

expertise and knowledge of the particular application domain. Thus, computer scientists

often become proficient in other subjects. Computer Science is practiced by mathematicians, scientists and engineers.

Mathematics, the origins of Computer Science, provides reason and logic. Science

provides the methodology for learning and refinement. Engineering provides the

techniques for building hardware and software.

10.1 MAJOR AREAS OF COMPUTER SCIENCE 1. Operating Systems--concerned with the development and structure of complex

programs which facilitate man-machine communications.

2. Computational Science--the analysis of numerical methods for solving

mathematical problems with a computer.

3. Programming Languages--the study of the design and properties of languages

by which humans communicate with computers.

4. Architecture--the study and use of mathematical logic to design electronic

circuits.

5. Intelligent Systems--concerned with means by which computers may perform

tasks which might be characterized as "intelligent" if performed by humans.

6. Automata Theory--an abstract study of computers and their capabilities.

7. Information Storage and Retrieval--the study of methods for storing a vast

amount of data in a computer and methods for searching and retrieving this data.

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8. Software Engineering--the study of tools and techniques for software design,

development, testing and maintenance.

9. Computer Network--the study of the principles of communication between

computers. Computer networking emphasizes the design of local area networks

(LANs), which connect computers within a small geographical area, and wide

area networks (WANs), which use telephone lines or radio waves to connect

computers thousands of miles apart.

10. Computer Graphics--which is related to graphic design and the visual arts,

combines video and computer technologies to produce two-, three-, and four-

dimensional graphic images (such as those seen in video games and computer-

animated films) using computers.

Computer Engineering: A broad discipline that incorporates the fields of computer

science and electrical engineering. Computer engineering emphasizes the theory, design,

and development of computers and computer-related technology including both hardware

and software

10.2 BEST JOB OPPORTUNITIES OF COMPUTER SCIENCE

PROFESSIONALS 1. Software Developer

These professionals design and program the computer applications we all use

each day

2. Information Security Analysts

These professionals are responsible for making sure that data on company

websites and servers is protected from theft and fraud

3. Computer Systems Analysts

These professionals design the ideal systems for businesses and organizations and

help implement these designs

4. Computer and Information Systems Manager

These professionals are typically the information technology leader in an

organization.

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5. Computer and Information Research Scientists

These professionals do research to solve complex computer problems in a variety

of industries, and invent new ways to approach the ways we use technology.

6. Computer Network Architect

These professionals are responsible for building connections between several

businesses or a huge network of users

7. Network and Computer Systems Administrators

As a systems administrator, these professionals are responsible for the day-to-day

operations of the physical computer networks within organizations

8. Database Administrator

Database administrators use software to manage information capacity for

businesses, government bureaus, and other organizations.

9. Web Developer

These professionals are responsible for the look and functionality of company

websites, intranets, and applications

10. Computer Support Specialists

These professionals help troubleshoot software and hardware problems for large

and small companies alike.

11. FUTURE COMPUTER Predicting the future is hard and risky. But predicting the future in the

computer industry is even harder and riskier due to dramatic changes in technology and

limitless challenges to innovation. Our world is already much, much smarter than 10

years ago and as computing power doubles every 18 months, it’s propelling us towards a

radically different future. Engineers are already designing driverless cars that rely on Global Positioning

Systems (GPS) and laser sensors to avoid obstacles autonomously. By 2020, computer

intelligence will be everywhere, not just in the cars and the roads, but practically in every

object you see around you. This new world will require sophisticated intelligent

coordination software, voice, image, and motion recognition will transform human-

computer interfaces into a seamless interaction between the user and all the computing

devices in that person’s life.

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In the future, you might be able to talk to computers and robots the same way you

talk to your friends. Researchers are trying to break down the language barrier between

humans and computers, as part of a new program from the Defense Advanced Research

Projects Agency (DARPA), which is responsible for developing new technologies for the

U.S. military. The program — dubbed Communicating with Computers (CwC) — aims

to get computers to humans by enabling them to use spoken language, facial expressions

and gestures to communicate.

Figure 1.21: Future Computer

SUMMARY

At the end of this chapter Students are able to

Understand the fundamental concepts of computers such as

generation, types and working of computer.

Recognize the real world applications of computers.

Understand the importance of studying computer science and its

technologies.

Realize the modern computer thoughts and how it will be

extended to future computer.