* For IBPS, SBI P.O./Clericals, RBI “B: Grade and other Competitive Exams.

* The most comprehensive Book for candidates appearing in various competitive

Examinations on Fundamentals of Computer and computing environment

Handbook on

COMPUTER

AWARENESS with 15 sets of multiple choice questions

N K Gupta

a IBC Academy Publications

IBCA

Declaration: No part or whole of this book/publication may be re-produced, copied, stenciled, stored in a retrieval system and/or distributed in any form or by any means: mechanical, electronic, photocopying, scanning, recording, web-casting or otherwise without the written permission of the Publishers. The Publishers have acquired information in this book from the reliable sources. The Publishers or Distributers do not take any responsibility for the accuracy of the information published and the damages or loss, if any.

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Preface

Computer and modern electronic banking are the order of the day and these are aggressively been embraced by the Banking sector in India to meet the challenges of modern day banking. Core Banking Solution (CBS), Electronic Funds Transfer (EFT), Advanced Risk Management Solutions, explosive growth in ATMs across the country, to name a few, have transformed the Banking sector and have pleasantly enhanced the experience of the customers.

The syllabus of IBPS and SBI – Bank P.O. and Clerks examination has been changing in the recent times. The candidates may observe that the knowledge of Computer Awareness is significant, with 50 objective questions carrying 50 marks out a total of 225 marks, thereby comprising about 22.22% weightage. Every additional correct answer to the questions matters a lot in such highly competitive exams. where over 50 lakhs students participates. You can be less serious about the subject, only to your peril and risk of not getting adequate ranking in the CWE Score Card and miss call for personal Interviews, from the Banks.

The Employers expects the aspiring candidates to possess the basic knowledge about Computers, which could facilitate them in better appreciation of the nuances of modern day Banking. Knowledge provides you strength and courage to stand up and face the challenges. This Book – Handbook of Computer Awareness – is a sincere effort in this direction and would ensure that the candidate is well conversant with updated Computer concepts and basic knowledge of computing environment.

This Book is compiled by a Senior Banker with over 26 years of rich working experience in Banking Industry and he joined State Bank Group as a P.O. over 26 years ago. The Book coverage is comprehensive and the study material is described in a lucid manner and precisely, just right for your better understanding. The Glossary of Terminology and 15 sets of Multiple Choice Questions are quite exhaustive and you would certainly find these very useful.

The Book is immensely useful for Recruitment Exams. conducted by SSC, LIC-AAO, Railways also, and entrance tests for MCA, MBA, BBA and similar courses.

Best Wishes for your success.

N K Gupta

(mail your suggestions to nkeyjee@gmail.com)

INDEX

CHAPTER -1: HISTORY OF COMPUTERS (01 – 08 ) Computer Hardware

History of Computers Computer Generations-in Nutshell

CHAPTER -2: INTRODUCTION TO COMPUTERS ( 09 – 22 )

Types of Computers

Characteristics of Computers Anatomy of a Computer

How Computer Works Turning on the Computer and Logging off Operating system & Software

CHAPTER -3: COMPONENTS OF A COMPUTER ( 23 – 35 ) Computer Hardware

Input and Output Peripherals Computer Software

Networking Hardware Telecommunication Equipments

CHAPTER -4: HOW DOES A COMPUTER WORKS ( 36 – 44 )

How a computer works How does a computer process information What is computer memory

How are data stored – Storing devices

CHAPTER -5: MICROSOFT WINDOWS APPLICATION SOFTWARE ( 45 – 55 )

Evolution of Microsoft Windows software Windows Software Suite

Microsoft Word Microsoft Excel

Microsoft Access Microsoft PowerPoint

CHAPTER -6: OPERATING SYSTEM SOFTWARES ( 56-67 ) Operating System

Types of Operating System Various Operating Systems in use Components of an OS

Codebase

CHAPTER -7: COMPUTER LANGUAGES ( 68 – 79 )

Introduction to Programming Languages Type System

Computer Programming Languages

CHAPTER -8: INTERNET AND COMPUTER NETWORKS (80 – 93 )

Computer Networks

Server and Clients Peer-to-Peer Networking Networking Components

Communication Programs World Wide Web

Internet Connection Digital Signature Token Key

Internet Protocols Cloud Computing

CHAPTER -9: PROTECTING AGAINST COMPUTER VIRUS, WORM, TROJANS ( 94 – 108 )

Computer Virus - History

Computer Virus - Types Spyware Virus Programs

Stealth – Types Vulnerability and Counter measures

Malware

CHAPTER -10: MICROSOFT OFFICE APPLICATION SOFTWARE ( 109 – 125 )

Microsoft Word Microsoft Excel Microsoft Access

Microsoft PowerPoint

CHAPTER -11: MICROSOFT WINDOWS : SHORTCUT KEYS ( 126 – 133 )

MS Windows: Shortcut Keys (General Options) Microsoft Word: Shortcut Keys Microsoft Excel: Shortcut Keys

Microsoft Access: Shortcut Keys Microsoft PowerPoint:: Shortcut Keys

CHAPTER : ABBREVIATIONS USED IN COMPUTERS (i – x )

CHAPTER : GLOSSARY OF COMPUTER TERMINOLOGY (i – xix)

CHAPTER : OBJECTIVE TYPE QUESTIONS AND ANSWERS (0 1 – 64 ) PRACTICE TEST - 1 PRACTICE TEST – 2

PRACTICE TEST – 3 PRACTICE TEST – 4

PRACTICE TEST – 5 PRACTICE TEST – 6 PRACTICE TEST – 7

PRACTICE TEST – 8 PRACTICE TEST – 9

PRACTICE TEST – 10 PRACTICE TEST – 11 PRACTICE TEST – 12

PRACTICE TEST – 13 PRACTICE TEST – 14

PRACTICE TEST – 15 ANSWERS KEY

CHAPTER -1

History of Computers

Computer hardware is the collection of physical elements that comprise a computer system. Computer hardware refers to the physical parts or components of computer such as monitor, keyboard, hard disk, mouse, etc.

Hardware refers to objects that we can actually touch, like disks, disk drives, display screens, keyboards, printers, boards, and chips.

In contrast, software is untouchable. Software exists as ideas, application, concepts, and symbols, but it has no substance.

A combination of hardware and software forms a usable computing system.

Computing hardware evolved from machines that needed separate manual action to perform each arithmetic operation, to punched card machines, and then to stored-program computers. The history of stored-program computers relates first to computer architecture, that is, the organization of the units to perform input and output, to store data and to operate as an integrated mechanism.

Before the development of the general-purpose computer, most calculations were done by humans. Mechanical tools to help humans with digital calculations were then called "calculating machines or calculators. Later, these were called computers.

Analog computers, like those designed and built by Vannevar Bush before World War II were of this type. Numbers could be represented in the form of digits, automatically manipulated by a mechanical mechanism.

Computing hardware has become a platform for uses other than mere computation, such as process automation, electronic communications, equipment control, entertainment, education, etc. Each field, in turn, has imposed its own requirements on the hardware, which has evolved in response to those requirements, such as the role of the touch screen to create a more intuitive and natural user interface.

As all computers rely on digital storage, and tend to be limited by the size and speed of memory, the history of computer data storage is tied to the development of computers.

Earliest True Hardware

Devices have been used to aid computation for thousands of years, mostly using one-to-one correspondence with our fingers. The earliest counting device was probably a form of tally stick.

The abacus was early used for arithmetic tasks. What we now call the Roman abacus was used in Babylonia as early as 2400 BC. Since then, many other forms of reckoning boards or tables have been invented.

Several analog computers were constructed in ancient and medieval times to perform astronomical calculations. These include the Antikythera mechanism and the astrolabe from ancient Greece (c. 150–100 BC), which are generally regarded as the earliest known mechanical analog computers.

Wilhelm Schickard, a German polymath, designed a calculating clock in 1623. It made use of a single-tooth gear that was not an adequate solution for a general carry mechanism

In 1642, while still a teenager, Blaise Pascal started some pioneering work on calculating machines and after three years of effort and 50 prototypes, he invented the mechanical calculator.

Around 1820, Charles Xavier Thomas created the first successful, mass-produced mechanical calculator, the Thomas Arithmometer, which could add, subtract, multiply, and divide.

In Japan, Ryōichi Yazu patented a mechanical calculator called the Yazu Arithmometer in 1903. It consisted of a single cylinder and 22 gears, and employed the mixed base-2 and base-5 number system familiar to users to the soroban (Japanese abacus) Carry and end of calculation were determined automatically.

In 1801, Joseph-Marie Jacquard developed a loom in which the pattern being woven was controlled by punched cards. The series of cards could be changed without changing the mechanical design of the loom. This was a landmark achievement in programmability.

In 1833, Charles Babbage moved on from developing his difference engine (for navigational calculations) to a general purpose design, the Analytical Engine, which drew directly on Jacquard's punched cards for its program storage. In 1837, Babbage described his analytical engine, a general-purpose programmable computer,

employing punch cards for input and a steam engine for power, using the positions of gears and shafts to represent numbers.

Following Babbage, although unaware of his earlier work, was Percy Ludgate, an accountant from Dublin, Ireland. He independently designed a programmable mechanical computer, which was published in 1909.

Desktop Calculators

By the 20th century, earlier mechanical calculators, cash registers, accounting machines, and so on were redesigned to use electric motors, with gear position as the representation for the state of a variable. The word "computer" was a job title assigned to people who used these calculators to perform mathematical calculations.

In 1948, the Curta was introduced. This was a small, portable, mechanical calculator that was about the size of a pepper grinder.

The first all-electronic desktop calculator was the British ANITA Mk.VII, which used a Nixie tube display and 177 sub-miniature thyratron tubes.

Advanced Analog Computers

Before World War II, mechanical and electrical analog computers were considered the "state-of-the-art", and many thought they were the future of computing. Analog computers take advantage of the strong similarities between the mathematics of small-scale properties - the position and motion of wheels or the voltage and current of electronic components - and the mathematics of other physical phenomena,

Early Electronic Digital Computation

George Stibitz is internationally recognized as one of the fathers of the modern digital computer. While working at Bell Labs in November 1937, Stibitz invented and built a relay-based calculator that he dubbed the "Model K", which was the first to calculate using binary form.

There were three parallel streams of computer development in the World War II era;

The first stream largely ignored, and the second stream deliberately kept secret. The first was the German work of Konrad Zuse.

The second was the secret development of the Colossus computers in the UK.

The third stream of computer development was Eckert and Mauchly's ENIAC and EDVAC, which was widely publicized.

Zuse

In 1936, Konrad Zuse constructed first Z-series calculators featuring memory and (initially limited) programmability. Zuse's purely mechanical, but already binary Z1, finished in 1938, never worked reliably due to problems with the precision of parts.

Zuse also claimed to have designed the first higher-level programming language, which he named Plankalkül, in 1945, although it was implemented for the first time in 2000.

Colossus

During World War II, the British at Bletchley Park achieved a number of successes at breaking encrypted German military communications. The German encryption machine, Enigma, was attacked with the help of electro-mechanical machines called bombesm, designed by Alan Turing and Gordon Welchman.

Colossus was the world's first electronic programmable computing device. It used a large number of valves (vacuum tubes). It had paper-tape input and was capable of being configured to perform a variety of boolean logical operations on its data, but it was not Turing-complete.

Developments in America

In 1937, Claude Shannon showed there is a one-to-one correspondence between the concepts of Boolean logic and certain electrical circuits, now called logic gates, which are now ubiquitous in digital computers. Entitled A Symbolic Analysis of Relay and Switching Circuits, Shannon's thesis essentially founded practical digital circuit design.

George Stibitz completed a relay-based computer he dubbed the "Model K" at Bell Labs in November 1937. Their Complex Number Calculator was able to calculate complex numbers. It was the first computing machine ever used remotely, in this case over a phone line.

ENIAC

Built under the direction of John Mauchly and J. Presper Eckert, ENIAC (Electronic Numerical Integrator and Computer) was the first electronic general-purpose computer. It combined, for the first time, the high speed of electronics with the ability to be programmed for many complex problems. It could add or subtract 5000 times a second, a thousand times faster than any other machine. It also had modules to multiply, divide, and square root. High speed memory was limited to 20 words (about 80 bytes). The machine was huge, weighing 30 tons, and contained over 18,000 vacuum tubes. ENIAC was unambiguously a Turing-complete device. It could compute any problem (that would fit in memory).

Manchester "baby"

The Manchester Small-Scale Experimental Machine, nicknamed Baby, was the world's first stored-program computer, built by Frederic C. Williams, Tom Kilburn and Geoff Tootill, and ran its first program on 21 June 1948.

Although considered "small and primitive" by the standards of its time, it was the first working machine to contain all of the elements essential to a modern electronic computer. The SSEM had a 32-bit word length and a memory of 32 words.

History of Computers: In brief

Year Invention Inventor

16th century Abacus China

1617 Napier’s Bones John Napier 1642 First Calculating machine Blaise Pascal 1801 Card of holes for Weaving pattern Joseph Jacquard 1823-24 Difference Engine; Analytical engine Charles Babbage 1936 First Z-series calculators Konrad Zuse 1880 Tabulating machine using punch cards Herman Hollerith 1880 MARK-1 Howard Aitken & Grace Hopper 1946 ENIAC (Electronic Numerical & Calculator) J P Eckert & J W Mauchly 1947-49 EDSAC (Electronic Delayed Storage

Automatic Computer) John Von Newmann

1950 EDVAC (Electronic Delayed Variable Automatic Computer)

Moor School (the USA)

1951 UNIVAC-I (Universal Automatic Computer) J P Eckert & J W Mauchly

1953 Transistor Bell Labs (the USA) 1957 Fortran Language John Backus, IBM 1958 Integrated Circuit (IC) Jack Kilby & Robert Noyce 1959 COBOL language Grace Hopper 1964 BASIC language John Kemeny &Thomus Kurtz 1975 P6060, world's first personal computer Olivetti 1976 Apple 1 Steve Wozniak 1980 MS DOS Software Microsoft Corp. 1984 Macintosh PC or Mac PC Apple Corp. 1988 INTEL 486 Processor Intel Corp. 1991 Laws of WWW Tim Barners Lee 2000 Pentium-4 Processor Intel Corp. 2003 LCD Monitor Allen B Dumont 2004 Linux Software Richard Stallman 2007 Android OS Software Google Corp. (the USA) 2008 WINDOWS Explorer 8 Microsoft Corp.

COMPUTER GENERATIONS

First-Generation Machines

Even before the ENIAC was finished, Eckert and Mauchly recognized its limitations and started the design of a stored-program computer, EDVAC. In this generation of equipment, temporary or working storage was provided by acoustic delay lines, which used the propagation time of sound.

EDVAC was the first stored-program computer designed; however it was not the first to run. The first working von Neumann machine was the Manchester "Baby" or Small-Scale Experimental Machine, developed by Frederic C. Williams and Tom Kilburn, in 1948 as a test bed for the Williams tube.

EDSAC was actually inspired by plans for EDVAC (Electronic Discrete Variable Automatic Computer), the successor to ENIAC. Unlike ENIAC, which used parallel processing, EDVAC used a single processing unit. The design was simpler and it was the first to be implemented in each succeeding wave of miniaturization, and increased reliability.

in 1950, the first universal programmable computer in the Soviet Union – MSEM, was created by a team of scientists under direction of Sergei Alekseyevich Lebedev. It had about 6,000 vacuum tubes and consumed 25 kW of power. It could perform approximately 3,000 operations per second.

In 1949, another early machine, an Australian design - CSIRAC was developed which remains the oldest computer still in existence and the first to have been used to play digital music.

Commercial Computers

The first commercial computer was the Ferranti Mark 1, developed in February 1951. It was an improved version of Manchester Mark 1. The main improvements over the Manchester Mark 1 were in the size of the primary storage (using random access Williams tubes), secondary storage (using a magnetic drum), a faster multiplier, and additional instructions. The basic cycle time was 1.2 milliseconds, and a multiplication could be completed in about 2.16 milliseconds. The multiplier used almost a quarter of the machine's 4,050 vacuum tubes (valves).

In 1952, IBM publicly announced the IBM 701 Electronic Data Processing Machine, the first in its successful 700/7000 series and its first IBM mainframe computer. The IBM 704, introduced in 1954, used magnetic core memory, which became the standard for large machines. The first implemented high-level general purpose programming language, Fortran, was also developed at IBM for the 704, and released in early 1957.

IBM introduced its first magnetic disk system, RAMAC (Random Access Method of Accounting and Control) in 1956. Using fifty 24-inch (610 mm) metal disks, with 100 tracks per side, it was able to store 5 megabytes of data at a cost of $10,000 per megabyte ($90 thousand as of 2012).

Second Generation Machines: Transistors

The bipolar transistor was invented in 1947. Transistors replaced vacuum tubes in computer designs, giving rise to the "second generation" of computers. Initially the only devices available were germanium point-contact transistors, which although less reliable than the vacuum tubes, they had the advantage of consuming far less power.

The first transistorised computer was built at the University of Manchester and was operational by 1953; a second version was completed there in April 1955.

Compared to vacuum tubes, transistors have many advantages: they are smaller, and require less power than vacuum tubes, so give off less heat. Silicon junction transistors were much more reliable than vacuum tubes and had longer, indefinite, service life. Transistorized computers could contain tens of thousands of binary logic circuits in a relatively compact space. Transistors greatly reduced computers' size, initial cost, and operating cost.

Typically, second-generation computers were composed of large numbers of printed circuit boards such as the IBM Standard Modular System each carrying one to four logic gates or flip-flops.

Transistorized electronics improved not only the CPU (Central Processing Unit), but also the peripheral devices. The IBM 350 RAMAC was introduced in 1956 and was the world's first disk drive. The second generation disk data storage units were able to store tens of millions of letters and digits. Next to the fixed disk storage units, connected to the CPU via high-speed data transmission, were removable disk data storage units. A removable disk stack can be easily exchanged with another stack in a few seconds. Even if the removable disks' capacity is smaller than fixed disks, their interchangeability guarantees a nearly unlimited quantity of data close at hand. Magnetic tape provided archival capability for this data, at a lower cost than disk.

During the second generation remote terminal units saw greatly increased use. Telephone connections provided sufficient speed for early remote terminals and allowed hundreds of kilometers separation between remote-terminals and the computing center. Eventually these stand-alone computer networks would be generalized into an interconnected network of networks—the Internet.

Third Generation Machines and beyond : Post-1960

The explosion in the use of computers began with "third-generation" computers, making use of Jack St. Clair Kilby's and Robert Noyce's invention of the integrated circuit (or microchip), which led to the invention of the microprocessor. It is largely undisputed that the first single-chip microprocessor was the Intel 4004, designed and realized by Ted Hoff, Federico Faggin, and Stanley Mazor at Intel.

During the 1960s there was considerable overlap between second and third generation technologies. IBM implemented its IBM Solid Logic Technology modules in hybrid circuits for the IBM System/360 in 1964.

Minicomputers served as low-cost computer centers for industry, business and universities. It became possible to simulate analog circuits with the simulation program with integrated circuit emphasis, or SPICE (1971) on minicomputers.

The microprocessor led to the development of the microcomputer, small, low-cost computers that could be owned by individuals and small businesses. Microcomputers, the first of which appeared in the 1970s, became ubiquitous in the 1980s and beyond.

In April 1975, Olivetti produced the P6060, the world's first personal computer with built-in floppy disk: Central Unit on two plates, with 32 alphanumeric characters plasma display, 80 columns graphical thermal printer, 48 Kbytes of RAM, BASIC language, 40 kilograms of weight.

The first Apple computer with graphic and sound capabilities came out well after the Commodore PET. Computing has evolved with microcomputer architectures, with features added from their larger brethren, now dominant in most market segments.

Computer Generations (in Nut shell)

Generation/ Year

Switching Device

Operating System Software

Speed Storage Device

Language Application

First Generation

1949 -54

Vacuum Tubes/ Electronic valves

Mainly Batch

333 micro seconds

Acoustic delay lines and later magnetic drum, 1 KB memory

Machine and assembly languages, Simple monitors

Mostly scientific later simple business systems

Second Generation

1954 -64

Transistors Multi bag remaining ; Time sharing

10 micro seconds

Magnetic core, main memory, tape and disk peripheral memory, 100 KB main memory

High level languages, Fortran, Cobol, Algol, Batch, Operating system

Extensive business applications, Engineering design optimization scientific research

Third Generation

1964 -80

Integrated circuits (ICs)

Real time/ Time sharing

100 nano seconds

High speed magnetic cores, Large disks 100 MB, 1 MB main memory

Fortran IV, Cobol 68, PI/I, Time sharing Operating system

Database management systems, On-line systems

Fourth Generation

1980 - continued

Large-scale Integrated circuits (ICs)/ Micro-processors

Time sharing networks

300 nano seconds

Semi-conductor memory, Winchester disk, 10 MB main memory, 1000 MB disks

Fortran 77, Pascal, ADA, Cobol-74

Personal computers, Distributed systems, Integrated CAD/CAM, Real time control, Graphics oriented system

Fifth Generation Computing devices are in the development phase and they are expected to deploy Knowledge Information Processing systems (KIPS) and Very Very Large scale Integrators known as Artificial Intelligence (AI).

CHAPTER -2

An Introduction to Computers

COMPUTERS

A computer allows users to store and process information quickly and automatically.

A computer is a programmable machine. It allows the user to store all sorts of information and then ‘process’ that information, or data, or carry out actions with the information, such as calculating numbers or organizing words.

Data: The representation of information in a formalised manner suitable for communication, interpretation and processing, generally by a computer system.

The term ‘raw data’ refers to unprocessed information.

According to the definition, the broad functions of a computer may be described as :

- To accept data input in it,

- To process the data ,

- To generate output, in the manner required by the user,

- To store the data/output for future use.

TYPES OF COMPUTERS

Computers are classified in to microcomputers, minicomputers mainframe Computers, and supercomputers. Microcomputers may be either personal computers (PCs) or workstations. PCs include desktop units, laptops, notebooks, subnotebooks, Tablet PC, Pocket PCs (electronic organizers, palmtops, personal digital assistants), and pen computers. Workstations are some sophisticated desktop microcomputers used for technical purposes.

Minicomputers are intermediate size machines that have become important as “servers,” for holding databases and programs for many PCs.

Mainframes are the large size of computer and are used in large companies to handle millions of transactions. The high-capacity minis called super computers are the fastest calculating devices and are used for large-scale projects. Super computers have two designs: vector processing and massively parallel processing.

Generally said, the larger the computer, the greater its processing power.

I. MICRO-COMPUTERS OR PERSONAL COMPUTERS:

A small, relatively inexpensive computer designed for an individual user is called personal computers (PC) or Micro-computers. Prices of personal computers ranges anywhere from a few thousands to over fifty thousand rupees, depending largely on the configuration and based on the microprocessor technology that enables manufacturers to put an entire CPU on one chip. 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 for playing games and watching movies as well.

Personal computers first appeared in the late 1970s. One of the first and most popular personal computers was the Apple II, introduced in 1977 by Apple Computer, followed by IBM in 1981. Today, the world of personal computers is basically distinguished between Apple Macintoshes (called Mac) and PCs.

The principal characteristics of personal computers is that it is a single-user system and based on microprocessors, however, it is common to link them together to form a network. In terms of power, there is great variety. At the high end, the distinction between personal computers and workstations has faded. High-end models of the Macintosh and PC offer the same computing power and graphics capability as low-end workstations by Sun Microsystems, Hewlett-Packard, and DEC.

Microcomputers or PC comes in various sizes, such as :

(a) Desktops : A computer designed to fit comfortably on top of a desk, typically with the monitor sitting on top of the computer/table. Desktop model computers are broad and low, whereas tower model computers are narrow and tall. Because of their shape, desktop model computers are generally limited to three internal mass storage devices. Desktop models designed to be very small are sometimes referred to as slim line models.

(b) Laptop Computers : A small, portable computer -- small enough to sit on your lap.

Some laptops are designed for specific purposes and their sizes reduced are/or customized and these are called Net Books computers.

(c) Notebook Computers: An extremely lightweight personal computer. Notebook computers typically weigh less than 6 pounds and are small enough to fit easily in a briefcase. Aside from size, the principal difference between a notebook computer and a personal computer is the display screen. Notebook computers use a variety of techniques, known as flat-panel technologies, to produce a lightweight and non-bulky display screen.

In terms of computing power, Laptops, modern notebook and Net Book computers are nearly equivalent to personal computers. These come with the same CPUs, memory capacity, and disk drives. However, all this power in a small package is expensive. Notebook computers thus cost about twice as much as the regular-sized computers.

(d) Pocket or hand-held computer: A portable computer that is small enough to be held in one’s hand. Although extremely convenient to carry, handheld computers have not replaced notebook computers because of their small keyboards and screens. The most popular hand-held computers are those that are specifically designed to provide PIM (personal information manager) functions, such as a calendar and address book.

(e) Tablet PC : A Tablet computer or a Tablet, is a mobile computer, larger than a mobile phone or personal digital assistant, integrated into a flat touch screen and primarily operated by touching the screen rather than using a physical keyboard. It often uses an onscreen virtual keyboard, a stylus pen, or a digital pen. The term may also apply to a variety of form factors that differ in position of the screen with respect to a keyboard. The standard form of tablet does not have an integrated keyboard but may be connected to one with a wireless link or a USB port. Convertible notebook computers have an integrated keyboard that can be hidden by a swivel joint or slide joint, exposing only the screen for touch operation. Hybrids have a detachable keyboard so that the touch screen can be used as a stand-alone tablet.

In 2010, Apple released the iPad, which used the operating system and touch screen technology similar to that used in their iPhone and became the first mobile computer tablet to achieve worldwide commercial success. This has sparked a new market for tablet computers and a variety of other manufacturers have produced versions of their own including Samsung, HTC, Motorola, RIM, Amazon, HP, Microsoft and many other. Competing Tablets use a variety of operating systems, although the main contenders are iOS (Apple), Android (Google), Windows (Microsoft) and QNX (RIM).

Typical features of Tablet computers are :

Wireless mobile browser function (using 2G, 3G, 4G or WiFi)

E-mail and Social Media devices (typically with integrated apps to bring all feeds into the same view)

Potential cell phone functions (Massaging, video calling, Speaker phone or Head set cellphone user)

GPS Satellite navigation

Stills and video camera functions, photo and video viewing and editing

E-book reading (including electronic versions of periodicals)

Downloadable apps (Games, education, utilities)

Portable media player function

Weigh around one or two pounds (0.50 – 1 kilogram)

Battery life of three to twelve hours depending on usage pattern

POCKET COMPUTERS may be classified into three types, in terms of their usage :

(i) Electronic organisers or Electronic Diary are specialized pocket computers that mainly store appointments, addresses, and “to do” lists. Recent versions feature wireless links to other computers for data transfer. Electronic organizers can share stored data with a PC through a connecting wire or through Bluetooth.

(ii) Palmtop: A small computer that literally fits in your palm is called palm top. Compared to full-size computers, palmtops are severely limited, but they are practical for certain functions such as phone books and calendars. Palmtops that use a pen rather than a keyboard for input are often called hand-held computers or PDAs.

(iii) PDA : PDA stands for Personal Digital Assistant, a handheld device that combines computing, telephone/fax, and networking features. A typical PDA can function as a cellular phone, fax sender, and personal organizer. Unlike portable computers, most PDAs are pen-based, using a stylus rather than a keyboard for input. This means that they also incorporate handwriting recognition features. Some PDAs can also react to voice input by using voice recognition technologies.

(iv) Pen computer: A computer that utilizes an electronic pen (called stylus) rather than a keyboard for input is called pen computer. Pen computers generally require special operating systems that support handwriting recognition so that users can write on the screen or on a tablet instead of typing on a keyboard. Most pen computers are hand-held devices, which are too small for a full-size keyboard.

2. MINI-COMPUTER:

A mid-sized computer - in size and power, mini computers lie between microcomputer and mainframes is called minicomputer. A minicomputer is a multiprocessing system capable of supporting from 4 to about 200 users simultaneously.

Traditionally, minicomputers have been used to serve the needs of medium-sized companies or of departments within larger companies, often for accounting or design and manufacturing with CAD/CAM software also..

A server is a computer on a network that manages network resources. The entire network is called Client-Server Network. For example, a file server is a computer and storage device dedicated to storing files. Any user on the network can store files on the server. A print server is a computer that manages one or more printers, and a network server is a computer that manages network traffic. A database server is a computer system that processes database queries.

Servers are often dedicated, meaning that they perform no other tasks besides their server tasks. On multiprocessing operating systems, however, a single computer can execute several programs at once. A server in this case could refer to the program that is managing resources rather than the entire computer.

3. MAINFRAME

Mainframe computers are very large and expensive devices, capable of processing significantly large volume of data and supporting hundreds, or even thousands, of users simultaneously. In the hierarchy that starts with a simple microprocessor (in watches, for example) at the bottom and moves to supercomputers at the top, mainframes are just below supercomputers. In some ways, mainframes are more powerful than supercomputers because they support more simultaneous programs. But supercomputers can execute a single program faster than a mainframe.

Unisys and IBM are the largest manufacturers of mainframes.

4. SUPERCOMPUTERS

The fastest type of computer is called supercomputer. Supercomputers are very expensive and are capable of processing very large volume of data and employed for specialized applications that require immensely large and advanced mathematical calculations. For example, weather forecasting requires a supercomputer. Other uses of supercomputers include animated graphics, fluid dynamic calculations, nuclear energy research, and petroleum exploration.

Computers can be classified into the following categories, according to their usage and working system:

Analog Computer: An Analog computer is a form of computer that uses the continuously changeable aspects of physical phenomenon such as electrical, mechanical and hydraulic quantities to model the problem being solved. The Analog computer works on the supply of continuous electrical impulses. Analog computers are extraordinarily fast, since they can solve most complex equations at the rate at which a signal transverse the circuit, which is generally an appreciable fraction of the speed of light. However, the precision of Analog Computer is considered insufficient, for they are limited to three or a maximum of four digits of precision.

Digital Computer: This is a general purpose high speed devices that can be programmed to carry out a finite set of mathematical calculations, compare values and store the results or performing logical operations. Digital computer takes the solution of equation to almost unlimited precision, but quite slowly as compared to Analog computer. For many real-time operations, the speed of digital Computers are considered too slow, such as – very high frequency phased array radar for weather calculations, but the precision of Analog Computer is considered insufficient, while accuracy of Digital computers are not questionable.

Hybrid Computer: Such computer exhibit features of both, Analog and Digital computers and finds application in scientific applications and industrial usage. The digital components normally serve as the controller and provide logical operations, while the analog components normally serve as a solver of differential equations. Hybrid computer are used to obtain a very good but relatively

imprecise seed value, using an analog computer front-end, which is then fed into a digital computer iteration process to achieve the final desired level of accuracy.

APPLICATION OF COMPUTERS

Major technical innovations have always had a severe impact on the lives of individuals. Same is true for computers also. Computers have entered every area of the society and organizations, where individuals work. Computers are being used in almost every sphere of activity ranging from home to defense and entertainment to business and commerce. Let us see how computers are used in various spheres of our life today.

Defence : Today, without computers, our defense could become grossly vulnerable. We may recall the recent American-Iraq war in which the American Army used computers extensively to launch missiles, track enemy aircrafts using radars, plan attacks and strategies etc. The entire operation was conducted by commanders remotely, sitting in distant places.

Homes : Computers are increasingly becoming smaller in size, affordable and easy to operate and use. These are finding their way into homes where they are used for keeping accounts, study, sending mail, playing games etc.

Science and Engineering: Computers are used to solve complex mathematical and scientific calculations which would otherwise require years of effort. Before computers, the launching of spacecraft and landing on the moon would have been distant dreams. In addition to assisting in technical matters, computers aid the administrators to keep records, accounts, maintain libraries of periodicals, journals, published papers etc.

Entertainment: Increasing use of computers is made in this field. The movies such as “Jurassic Park”, “Independence Day”, “Terminator”, “Titanic”, “Ra-One” and “Jaws” have used animation created on computers extensively to give special effects to the images. Today compact disk (CDs) used in record players are examples of computer technology having invaded this area.

Computers enable sound, audio and images to be combined to help film makers, advertisement agencies to quickly produce films or advertisement clips. Animation films, till recently were difficult to make, are now easily produced with the help of graphics or computers.

Transportation: Transportation companies and agencies rely on computers. Railway reservations are now done, real time basis, on computers. Apart from enabling quicker reservations, it has enabled persons to plan journeys from any place to any other place with greater ease and less worry. The cargo movement is also computerised which, not only impart efficiency to the handling but also enable a consignor to know the exact status of his consignment in a few moments.

Business and Finance: No other sphere of activity has been as profoundly affected by computers as banking and finance. The volume of business of banking after introduction of computers has grown more than thousand fold. Right from automatic

maintenance of customer ledgers, identification of customers to payment of cash up to back office functions, such as balancing of books, MIS, funds transfer and reconciliation are all computerised. The Core Banking Solution (CBS) has facilitated Banks in offering virtual banking and “Anywhere Banking” to their customers across the Globe, breaking the barriers of brick and mortar branches.

Most banks abroad are fully dependent on computers for their functioning and even a half-an hour halt in the computer functions cost them millions of dollars. Even in India, private banks and co-operative banks have started fully computerized banking.

Hospitals and Medicine: As the number of patients keeps growing, big hospitals have no option but to computerise their records to enable tracking the patients’ history to help doctors in diagnosing and administering medicine. Inventories of medicine are also computerised so that availability of medicines is readily known and stock-outs are avoided. With the improvement of technology, electronics and computers are being used in increased measures for diagnosing patients. Pharma companies use computers in various ways such as for designing experiments, analysing results of experiments and even formulation of drugs.

Other Areas : Other spheres of activity where computers are being used are in schools and education, by Govt., in maintenance of records, administration and decision-making called e-governance by the tele-communication sector for switching, store and forward facility, consumer billing & maintenance etc. the industry for production planning, inventory, sales and purchase etc.

Commerce: It is the commercial world - shops, banks, insurance and credit companies - which makes the maximum use of computers in a variety of applications. It will be very difficult for the financial world to exist without the assistance of computers. The introduction of micro-computers enables the offices to function faster and efficiently. A number of software packages are used in business. Besides word processing, other packages used in the offices are spread sheet, database management system, presentation software, specialized accounting software etc.

Industry: Many industrial organisations such as steel, chemical, oil companies depend largely upon computers not only for their own internal administration but also for the actual control of the plant processes. The trend has increased with the advent of microcomputers. Many assembling work of the industry are being undertaken by the processes controlled by micro-computers.

Administration: Every organisation has its own internal administration, and the administrative tasks are performed by computers.

Education: Although there is a very little impact of computers in the class-room of Indian schools. In USA and UK, computer aided methods such as - Computer Assisted Learning (CAL) and Computer Assisted Instructions (CAI) exist. Education is the area, where computers have a major role to play, especially in Universities - more so in the science and technology department.

CHARACTERISTICS OF COMPUTERS

The vital characteristics of the computer are as follows:

I. Speed : Computer works on electrical pulses, which travel at incredible speeds and, because the computer is electronic device, its internal speed is instantaneous.

An arithmetic calculation can be performed in a thousandth, millionth, billionth or even in a trillionth of second. It is capable of executing over ten thousand instructions in a second.

MILLISEC ms = 1/1000 of second.

MICROSEC ms = 1/1,000,000 of second

NANOSEC ns = 1/1,000,000,000 of second

PICOSEC ps = 1/1,000,000,000,000 of second

II. Storage: This is a very vital characteristic of the computer, which separates it from rest of the machines. The smallest unit of storage is bit (acronym of Binary DigiT).

The speed with which a computer can perform, i.e. to input data and the instructions for processing, is humanly impossible. The storage space available in the Central Processing Unit, being limited, large quantity of data and entire instructions of all the required programs cannot be stored in it. These are stored outside and read into the memory of CPU at the time of processing.

BIT - the smallest unit of storage,

NIBBLE = 4 bits,

BYTE = 8 bits,

KB = 1024 bytes,

MB = 1024 KB,

GB = 1024 MB

III. Accuracy: Accuracy of computers is consistently high. Errors in computing are due to machinery failure, imprecise programming logic, inaccurate data, poorly designed systems. Precision is the degree of accuracy to which the computer gives the result. The precision of computers is phenomenal and unquestionable.

BITS, BITES and THEIR LIKELY SIZE (IN WORDS)

UNIT SIZE DESCRIPTION

Bit One Binary Digit Stores either a Binary 0 or 1

Byte Eight bits One character

Word 16 to 64 bits One character

Kilobyte 1 thousand bytes About one page of double spaced text

Megabyte 1 million bytes About the size of a short book

Gigabyte 1 billion bytes About the size of 1000 short books

Terabyte 1 trillion bytes About the size of an entire library

Petabyte 1 quadrillion bytes Just about all the libraries in the country

IV. Versatility: Computers seem capable of performing almost any task, provided the task can be reduced to series of logical steps. It performs numeric and non-numeric tasks equally well. An algorithm, a step-by-step procedure which applied to the problem leads to solution. Programming is to convert these step-by-step procedures as a set of instructions in computer language to solve the problem.

V. Automation: Once a program is in the computer’s memory, CPU follows the instructions until it meets the last instruction. Once the process had begun, it would continue without human intervention until completion.

VI. Diligence: Being a machine, a computer does not suffer from the human traits of tiredness and lack of concentration. If three million calculations are to be performed, computer performs all these calculations with the same speed and accuracy.

ANATOMY OF A COMPUTER

There are broadly two main types of computers, desktops and laptops and have the following components:

THE MONITOR

The monitor looks like a television screen and shows whatever activity is happening in the computer. By using shadows and graphics with over a million different colors, much of what appear is 3-dimensional. Consider of this as the ‘face’ of the computer.

THE CPU (Central Processing Unit)

The CPU houses the machinery that allows your computer to work and called ‘brains’ of the computer. This component looks very different in desktops and laptops, but it works the same.

THE KEYBOARD

The keyboard is one of two ways to interact with your computer. The keys should mostly mimic a traditional typewriter, rather with enriched features.

THE MOUSE

This is the other way to interact with your computer. Mostly , it has two buttons—a right and a left button—and a scrolling wheel in the middle.

How Computers Work

Hardware / Software

Computers use both hardware and software to perform their work. While the Hardware is the physical pieces of a computer—the monitor, the CPU, all the pieces and parts inside the CPU, the mouse, the keyboard, etc.,

Software, on the other hand, consists of programs that we use to interact with the computer. You can’t physically touch software like you can the keyboard, but you can still interact with it.

A word processing program like Microsoft Word is a piece of software. Games that we play on the computer are also software— though these are unrelated to work.

Information / Data

Computers are designed to work with a type of information commonly referred to as “data.” Data comes in many forms, whether it is written data (such as a letter to a friend), audio data (like a song), video data (like a popular movie or DVD), and more. Certain types of software programs work with different types of data. For example, the iPod works primarily with audio data, while Microsoft Word, a word processing program, works primarily with written data.

The keyboard is just one of the ways in which you can create, interact with, and modify data. There are many ways to get data off of the computer, such as printing it out on paper, copying it to a CD or flash drive, or publishing it to the Internet.

“My Computer is a prized Possession!”

It is a common misconception that computers have “a mind of their own.” Although computers can perform certain tasks much more easily and faster than humans (like counting, performing mathematical calculations, etc.), they are, in the end, machines and can’t think for themselves. It is safe to say that the computer cannot do anything that you do not tell it to do. Remember that you are in control of the computer, in the same way that you are in control of your car.

Keeping the Computer Healthy

In the end, computers are machines just like any other. Sometimes, although not often, they may malfunction, become stuck (or “frozen”), or may have a part that breaks and need to be replaced. Keeping virus software up-to-date, installing updates to operating system (viz. Windows updates), and refraining from installing unnecessary programs shall keep the computer running smoothly and efficiently for a longer period of time.

Some Facts About Computers

The internet is a way of connecting to other computer users. One can connect to the internet using a phone line, a cable connection, or by using a wireless connecting device (wi-fi).

A computer does not need to access the internet in order to run properly.

A computer is able to perform most common functions (play music, type documents, edit pictures) and run programs without an internet connection. However, to view a web page or send an email, you will need an internet connection.

A computer needs an Operating System in order to work, though any new computer we purchase comes along a pre-installed operating system, such as Microsoft Windows or Macintosh OS X.

Turning On the Computer and Logging On:

Turning the Computer On

Let's get started!

OFF: This is exactly what it sounds like: The computer is off, and no parts are working. The monitor is black (no images), there is no “whirring” sound from the CPU, and the computer is unresponsive to mouse movements or pressing keys on the keyboard. The power button (if it lights up) should not be lit up.

ON: When a computer is on, you should see images on the monitor, possibly hear a “whirring” noise coming from the CPU (not too loud!), and the pointer on the screen should respond when you move the mouse.

SLEEP MODE: Most computers have a mode called “Sleep,” in which the computer is on, but has assumed an energy-efficient, minimal power mode. To “wake” the computer, simply move the mouse around or press the space bar on the keyboard, and it will “wake up” and return to the exact same place that it was when it went to sleep.

Logging On

Once you turn the computer on, the computer will go through a series of automated tasks before it is ready for you to interact with it; this process is called “startup.” This process will last between one and two minutes. If the computer is not working correctly, an error message appears during the startup.

Should the computer is password-protected, a window called “Log On” window appears. To log on, simply enter user name and password. Should this window does not appear upon starting the computer, it is safe to assume that your computer is NOT password-protected and may be used by anyone.

The Desktop

After you log on, the computer will display what is known as your desktop within a few seconds to a few minutes. Here you will see a digital representation of something similar to a real-life office space, complete with a workspace, files and file folders, and even a recycling bin!

One of the neatest features about Microsoft Windows is that it can be personalized, altered, and changed –almost everything on the desktop environment. If you do not like the color blue as your background, where the icons are, or even what language it is in, these can be changed!

THE KEYBOARD AND MOUSE

Keyboard Commands

In order to use your computer effectively, one must interact with it using both the mouse and the keyboard. The following is a list of commonly used keys that have special functions: (note: key functions may change depending on the program you are using)

1. Backspace: This key deletes letters backward.

2. Delete: This key deletes letters forward.

3. Shift: This key, when pressed WITH another key, will perform a secondary function.

4. Spacebar: This key enters a space between words or letters.

5. Tab: This key will indent what you type, or move the text to the right. The default indent distance is usually ½ inch.

6. Caps Lock: Pressing this key will make every letter you type capitalized.

7. Control (Ctrl): This key, when pressed WITH another key, performs a shortcut.

8. Enter: This key either gives you a new line, or executes a command (pressed in a word processing program, it begins a new line).

9. Number Keypad: These are exactly the same as the numbers at the top of the keyboard; some people just find them easier to use in this position.

10. Arrow Keys: Like the mouse, these keys are used to navigate through a document or page.

The Mouse

While the keyboard is primarily used to insert/input and manipulate text and numbers on a computer, the mouse is used mostly for navigating around the screen. Mouse comes in a variety of shapes and sizes. Some of the strangest-looking mouse often looks that way because they are designed to be more ergonomic than traditional mouse.

Pressing the LEFT mouse button is called “left-clicking,” while pressing the RIGHT mouse button is called "right-clicking."

Left-clicking is used far more often than right clicking. For now, know that left-clicking is used to select or click on something, while right-clicking presents additional menu options.

Left-Clicking, Double-Clicking and Right-Clicking

The mouse symbol, or pointer, that appears on the computer screen will change its look and function depending on what it is near or hovering over.

Your mouse pointer will most often look like an arrow.

When your mouse pointer is over an internet link, it will look like a pointing hand.

When your mouse pointer is over a place where you can type, it will look like an I-beam.

When your computer is busy or ‘working,’ your mouse pointer may look like an hourglass or a spinning circle.

There are actually many different pointers (though these are the most common), and they will change automatically depending on what task you are trying to perform.

The buttons on the mouse may also have different functions, depending on which program you are using. If you are working in Microsoft Word, for example, the mouse will offer options related to Microsoft Word. Conversely, if you are working in Microsoft Excel, the mouse will offer options related to Microsoft Excel, and so on, such as :

1. The LEFT mouse button SELECTS items.

2. The RIGHT mouse button GIVES YOU MORE OPTIONS.

3. Double-Clicking the LEFT mouse button EXECUTES options (for example, opening a program by double-clicking an icon on the desktop).

4. Double-Clicking the RIGHT mouse button does not do anything.

OPERATING SYSTEMS AND SOFTWARE

The Operating System

Computers without operating systems are exactly like televisions without a signal.

The most popular operating system is “Microsoft Windows,” and it is utilized by most personal computer (PC) users. It is a program that acts as the brains of the computer, allowing it to run other programs, work on projects, and do basically everything else that computers are capable of. There are many different versions of Microsoft Windows, and a new version is released every couple of years.

There are other operating systems as well. Apple manufactures a computer called Macintosh, or Mac. Macs use an operating system called “Mac OS X” which, while it looks very different from Microsoft Windows, runs using the same basic principles. While fewer people use Macs than PCs, and it is mostly used by the people who work

with graphic design and video and image editing. Macs tend to be more expensive than PCs.

The Start Menu

The Start Menu is a good place to, well, start! The Start button (which opens the menu) is located in the lower left corner of the screen. LEFT-CLICK once on the Start Button to open the menu.

The “Shut Down” button at the bottom of the menu is very important and functions kind of like a car. It allows to log off or shut down the computer. Logging off a computer is like locking a car—the computer is in a stationary mode and you can’t do anything. Clicking Shut Down is like turning off the engine. When you click Shut Down, the computer has an opportunity to properly “shut down” before the power is turned off.

By LEFT-CLICKING once on “All Programs,” another menu will appear- a list of all of the programs that are installed on the computer. Nearly everything that you can do with your computer can be found in the Start menu. This includes finding help, using programs, getting on the Internet, emailing, playing games, customizing your desktop, and more!

Managing “Windows”

Microsoft Windows has undergone many changes over the past few decades. New versions of the operating system are released every couple of years. It is currently being released in a version called “Microsoft Windows 7.” Past versions include: “Windows 95,” Windows 98,” “Windows ME,” “Windows XP,” and “Windows Vista.”

Microsoft Windows is called “Windows” for a reason. Programs appear on the screen as “Windows” (rectangular shapes) and are laid 3-dimensionally on top of one, just like on a real desktop. The desktop is your work surface, and all of your open windows appear on top of it.

If you can see a window, this means the program is open and running. It is possible to make the window bigger, smaller, or close it using the buttons in the top right corner of any window.

Minimize: Left-click this button to shrink the window down to a small button that will appear in the task bar.

Maximize: Left-click this button to make the window as large as it can be—it should take up the entire screen.

Close: Left-click this button to close the window. The program will close and stop running. Make sure you save your work first!

Restore Down: Left-click this button to make the window smaller without minimizing it.

Microsoft Windows is capable of running more than one program at once. In other words, you can write a letter in Microsoft Word, while surfing the Internet while using Microsoft Excel while checking your email and so on! This is called “multi-tasking” and

is a feature of all computers. However, with all of these things going on at once, how do we keep track of them all? The Taskbar, which is the bar that spans across the bottom of the screen next to the Start Menu, is designed to help keep track of all the open programs.

SHUTTING DOWN THE COMPUTER

Logging Off vs. Shutting Down

To log off or shut down the computer, click the Start button:

Logging off the computer and shutting down the computer are two different things. Remember the analogy of the car: Logging off a computer is like locking the car (the computer is in a stationary mode and you can’t do anything). When you first log in to a computer, it’s like using a key (password) to get in, and when you are done using the computer, you need to log off (the computer will remain on) to make sure no one can make changes while you are away.

By contrast, when you click Shut Down, it is like turning a car’s ignition off. You need to make sure that processes and programs are properly ended and shut down before pushing the shutdown button, just as with a car you have to turn off the ignition before pulling out the key. Click the Start button, then click Shut Down. Do not press the power button to turn off your computer!

After you have clicked Shut Down, your computer will begin a shut-down process. You may see a window that says, “Windows is shutting down.” When the computer is done shutting down, the screen will go black, and the computer tower will stop making any noise. It is now shut down. It is not necessary to press the power button -- Your computer will turn off automatically.