MODU L A R
S Y S TEM
INFORMATION AND COMMUNICATION TECHNOLOGY
Osman AY İlker TAYAN Ferhat AYDIN
http://book.zambak.com
Copyright © Zambak Yayýncýlýk ve Eðitim Gereçleri A.Þ. All rights reserved. No part of this book may be reproduced, stored in a retrieval system or transmitted in any form without the prior written permission of the publisher. Digital Assembly Zambak Typesetting & Design Editor Osman Ay Language Proofreader Marc D. Baldwin Page Design Mustafa Çimen Publisher Zambak Yayýncýlýk ve Eðitim Gereçleri A.Þ. Printed by Çaðlayan A.Þ. Gaziemir / İzmir, August 2012 Tel: +90-232 252 22 85 +90-232 522 20 96 / 97 ISBN: 978-605-112-382-0 Printed in Turkey
D I ST R I B U T I O N
Zambak Yayýncýlýk ve Eðitim Gereçleri A.Þ. Mahmutbey Merkez Mah. Soğuksu Cad. No. 31 Tek-er İş Merkezi Bağcılar / ÝSTANBUL Tel.: +90-212 604 21 00 Fax: +90-212 604 21 12 http://book.zambak.com
“Microsoft, MSN, Microsoft Office 2010, and Windows are either registered trademarks or trademarks of Microsoft Corporation in the United States and/ or other countries.”
CHAPTER 1: Introduction to Computers
Converting a Binary Number to Its Decimal Equivalent.. 23
What is a Computer?...................................................... 8
Octal Numbers and Hexadecimal Numbers ................... 24
HOW COMPUTERS WORK.............................................. 8 Booting Up Your Computer.............................................. 8 Data Flow in a Computer................................................. 8
TAKING CARE OF THE COMPUTER............................... 25 Clean Out the Dust........................................................ 25 Monitor Cleaning..............................................................25 Keyboard Cleaning............................................................25
TYPES OF COMPUTERS............................................... 10
Mouse Cleaning................................................................26
Mainframe Computers................................................... 10
Case Cleaning..................................................................26
Minicomputers.............................................................. 11
Keep Your PC Cool........................................................ 26
Supercomputers........................................................... 11
Buy Quality Hardware.................................................... 27
Microcomputers............................................................ 11
Get Power Protection.................................................... 27
THE HISTORY OF COMPUTERS.................................... 12 The Main Periods in the History of Computers............... 13 1. Vacuum Tubes (1930–1958)........................................13 2. Transistors (1959)........................................................13
Get an Anti-Virus Program............................................. 27 Scan for Other Malware................................................ 27 Run the Defragmenter Utility.......................................... 27 Clean Up Old Files......................................................... 27
3. Integrated Circuits (1965).............................................13
HEALTHY COMPUTER USE........................................... 28
4. Microprocessors (1971)...............................................14
Make Yourself Comfortable........................................... 28
5. Personal Computer (1981)...........................................14
Take a Break................................................................. 28
Important Inventions in the History of Computers.......... 14
Eyes and Eyesight ........................................................ 28
COMPUTERS IN EVERYDAY LIFE................................. 18
BUYING A COMPUTER................................................. 29
Communication............................................................. 18
Your Needs................................................................... 29
Education...................................................................... 18
Windows vs. Mac......................................................... 29
Astronomy and Space Technology................................ 19
Desktop vs. Laptop....................................................... 29
Press and Publishing.................................................... 19
When Choosing a Laptop..................................................30
Entertainment............................................................... 20
Hardware...................................................................... 30
Engineering, Architecture, and Design........................... 20
CPU..................................................................................30
Finance and Accounting................................................ 20 Banking........................................................................ 20 Biology and Medicine.................................................... 21 Military Services........................................................... 21
Memory (RAM)................................................................31 Hard Disk.........................................................................31 Monitor.............................................................................31 Disk Drives.......................................................................31 Sound and Video..............................................................31
MEASURING DATA (BITS AND BYTES)......................... 21
Software....................................................................... 31
Understanding Data....................................................... 21
Service, Support and Warranty..................................... 32
Decimal and Binary Number Systems........................... 22
Introduction.................................................................. 38
Converting a Decimal Number to Its Binary Equivalent.. 23
CHAPTER 2: Hardware The System Unit....................................................... 38 Chassis (Case)............................................................. 38 Power Supply............................................................... 40 Uninterruptible Power Supply (UPS)..................................40
Mainboard.................................................................... 42 The ROM-BIOS.................................................................43
Graphics Tablet (Pen Tablet).......................................... 79 Concept Tablet and Concept Keyboard.......................... 79 Webcam....................................................................... 80 Scanner........................................................................ 80 PC Microphone............................................................. 81 Joystick........................................................................ 82 Mouse.......................................................................... 83
System Buses..................................................................45
Output Devices........................................................ 85
The Bus Arbitration (Chipset)............................................46
Monitor......................................................................... 85
Expansion Slots................................................................47
Printer........................................................................... 87
ATA and ATAPI Interfaces..................................................49
Laser Printers...................................................................88
Peripheral Connectors.......................................................50
Impact (dot-matrix) Printers..............................................88
Internal Speaker............................................................ 51
Plotter........................................................................... 89
Central Processing Unit (CPU)....................................... 52
Speakers and Headphones............................................ 90
Inside a CPU.....................................................................53
Speaker............................................................................90
32-Bit and 64-Bit Architectures.........................................54
Headphone.......................................................................90
Single and Multi-Core Processors.....................................54 Intel Corporation ..............................................................55 Advanced Micro Devices (AMD).......................................56
Data Storage Devices............................................. 91 Hard Disk Drive............................................................. 92
VIA Technologies..............................................................56
Solid-State Drive (SSD)................................................. 94
Memory (RAM)............................................................. 56
Floppy Diskette (FDD)................................................... 95
Memory Hierarchy............................................................57
Magnetic Tape.............................................................. 95
Static RAM (SRAM)..........................................................58
Zip Disk........................................................................ 96
Dynamic RAM (DRAM).....................................................59
CD ROM Disk .............................................................. 96
Memory Latency..............................................................61
DVD Disk...................................................................... 97
Expansion Cards........................................................... 62
Blu-Ray Disk................................................................. 97
Some Types of Expansion Cards.......................................62 Video Card (Display Adapter, Graphics Card)....................63 Sound Card (Audio Card)..................................................66
CHAPTER 3: Software
Network Interface Card (NIC)............................................67
Introduction................................................................ 106
Modem (Modulator/Demodulator).....................................69
Operating Systems...................................................... 106
TV Card............................................................................70
Interface.........................................................................107
PC Card and ExpressCard.................................................71
Single or Multi-User........................................................108
SCSI Card........................................................................71
Stand Alone or Network..................................................108
Input Devices........................................................... 73
Single or Multi-Tasking....................................................109
Keyboard...................................................................... 73 Touch Screen................................................................ 78 Light Pen...................................................................... 79
MS-DOS .................................................................... 109 Most Common MS-DOS Commands...............................110
Microsoft Windows Family ......................................... 111
Educational software on custom platforms.....................129
Windows 98...................................................................111
Online Applications..................................................... 130
Windows NT ..................................................................112 Windows Server Family .................................................112 Windows XP ..................................................................112 Windows Vista ..............................................................113
UTILITY programs.................................................. 132 What are Utilities?....................................................... 132 Disk Defragmenters..................................................... 133
Windows 7 ....................................................................113
Disk Checkers ............................................................ 133
Mac OS...................................................................... 113
Disk Cleaners ............................................................. 133
Unix ........................................................................... 114
Disk Space Analyzers ................................................. 133
Linux.......................................................................... 114
Disk Partitions............................................................ 133
Novell NetWare........................................................... 115
Disk Compression Utilities ......................................... 133
BeOS and Haiku ......................................................... 116
Registry Cleaners ....................................................... 134
Mobile Operating Systems ......................................... 116
System Monitors and Profilers.................................... 134
Symbian OS...................................................................116
Antivirus Software...................................................... 134
Google Android...............................................................117
Network Utilities ......................................................... 135
Mobile Linux...................................................................117
Backup Utilities........................................................... 135
BlackBerry OS................................................................117
File Managers ............................................................ 136
iPhone OS......................................................................117
PROGRAMMING LANGUAGES.................................... 137
APPLICATION PROGRAMS......................................... 119
Introduction................................................................ 137
Word Processor.......................................................... 119
Compiling and Interpretation........................................ 137
Spreadsheet................................................................ 120
General-Purpose and Special-Purpose Languages....... 137
Presentation Software................................................. 121
Web Programming...................................................... 138
Database Management Software................................. 121
High-Level and Low-Level Languages......................... 138
CAD/CAM................................................................... 122
Some of the Popular Programming Languages............ 139
Painting and Drawing.................................................. 123
Assembly.......................................................................139
Vector Graphics..............................................................123
Fortran...........................................................................140
Raster Graphics..............................................................123
BASIC.............................................................................141
Major Graphic File Formats.............................................124
COBOL...........................................................................141
Raster Formats...............................................................124
Pascal and Object Pascal................................................142
Vector Formats...............................................................126
C, C++ and C# (C Sharp)............................................144
Page Layout and Desktop Publishing........................... 127
Java...............................................................................145
Animation Programs................................................... 128
Visual BASIC..................................................................145
Multimedia Applications.............................................. 128
Pyhthon..........................................................................146
Games........................................................................ 129
Java Script.....................................................................146
Educational Software.................................................. 129
Dart................................................................................146
Courseware....................................................................129 Classroom Aids..............................................................129 Edutainment...................................................................129
ASP / ASP.NET ...............................................................147 PHP................................................................................147 Cold Fusion....................................................................147 Ruby on Rails.................................................................148
CHAPTER 4: Networking Understanding Computer Networks............................. 152 Advantages of Networks.................................................152 Drawbacks of Networks..................................................152 Communication between Computers...............................153
Network Types............................................................ 153 LAN (Local Area Network)..............................................154 MAN (Metropolitan Area Network)...................................155 WAN (Wide Area Network)..............................................156 Comparing LAN, MAN and WAN.....................................157
Network Components.................................................. 157 Media.............................................................................157 Network Devices.............................................................159
Network Protocols...................................................... 161 Intranet, Extranet, and Internet..................................... 163
Star Topology.................................................................180 Tree Topology.................................................................181 Mesh Topology...............................................................181
Logical Topologies...................................................... 182 Logical Token Ring Topology..........................................182 Logical Ethernet Bus Topology........................................182
IP Addressing............................................................. 183 Understanding IP Addressing..........................................183 Types of IP Addresses....................................................183 Versions of IP Addresses................................................184
Network Management................................................. 185 Network Management Administrator...............................185
Network Security......................................................... 185 Different Network Security Threats..................................185 Blocking Threats with a Firewall......................................186
Intranet...........................................................................163 Extranet..........................................................................163 The Internet ...................................................................164 Internet Connection Types...............................................165
ANSWER KEY
Wi-Fi..............................................................................166
The Internet, Intranets, and Extranets........................... 167 WWW (World Wide Web)............................................ 167 Web 2.0.........................................................................167
Internet and WWW Tools............................................. 168 E-Mail.............................................................................168 IRC Chat and Instant Messaging.....................................169 FTP (File Transfer Protocol).............................................169 Cloud Computing............................................................171 Internet Telephony..........................................................171 Video Conference...........................................................172 Telnet.............................................................................173 Discussion Boards and Newsgroups...............................173 Social Media...................................................................174
Networking Models and Standards.............................. 175 The OSI Model................................................................175 TCP/IP Model.................................................................177
Network Topologies..................................................... 179 Bus Topology..................................................................179 Ring Topology................................................................179
INDEX
What is a Computer? System Unit
Monitor
A computer is an electronic machine that makes mathematical calculations and logical comparisons quickly and without any mistakes. Computers take data, process them according to a list of instructions, and show or store the results of the processing. They can store the results forever. Computers consist of two parts, hardware and software. Hardware is the physical parts of the computer. Software is the programs in the computer. Software tells the hardware what to do. The relation between hardware and software is like the relation between our body and our mind.
Keyboard Mouse
A desktop computer
HOW COMPUTERS WORK Booting Up Your Computer When you switch on your computer, a small initiating program BIOS (Basic Input/Output System or Built In Operating System) is loaded into memory (RAM). The BIOS software is written in a ROM on the mainboard. The primary function of the BIOS is to identify and initialize system hardware devices and to copy (load) the operating system software from permanent storage to RAM (Random Access Memory). This process is known as booting, or booting up, which is short for bootstrapping.
An Intel BIOS ROM chipset
Computers can store information in two different ways: in permanent storage (for example, on a disk or a CD) and in temporary storage, also called the computer’s memory or RAM. Data in temporary storage only last as long as the computer is switched on.
Data Flow in a Computer ROM (Read-Only Memory) can be read but not changed. It contains the basic information needed to start the computer. A long life battery in the computer sustains the memory when the computer is turned off. Data are placed in ROM only once and stay there permanently.
The mainboard is the central board in the computer that all devices are connected to.
8
When you switch on a computer, first, a special software called the operating system is copied (loaded) from permanent storage to the RAM. The computer gets data from an input device, such as a keyboard, mouse, hard disk, or scanner, and makes all the calculations and the comparisons in the central processing unit (CPU). The CPU is like the computer’s brain. It uses the RAM to maintain the data. When the CPU has processed the data, it sends the results to an output device, such as a monitor or printer, or saves them in a permanent storage device, such as a hard disk.
An Operating System is a master program that controls a computer’s basic functions and allows other programs to access the computer’s resources, such as disk drive, printer, keyboard, and screen. It provides the interface between a human and a computer. Microsoft Windows 7 and Linux are two examples of operating systems.
ICT - Information and Communication Technology
Storage Devices
2
1
3 CPU
RAM
Process Output Devices
Input Devices Data flow in a computer
Put a tick (√) to show if the statements are true or false. STATEMENT 1
Computers make calculations very fast.
2
Computers can compare numbers, such as 10 > 5.
3
Computers are electronic machines.
4
Computers are intelligent machines.
5
Computers don’t forget.
6
Computers can draw pictures.
7
Computers can work without any software.
8
Computers need food to work.
9
Computers are a kind of TV.
TRUE
FALSE
10 Computers make our lives easier.
Chapter 1: Introduction to Computers
9
Match the statements to compare computers and humans. 1
A computer never gets tired and can work continuously.
2
A computer is an electronic machine.
A human performs mathematical b. operations slowly and can make mistakes.
3
Computers need electricity to work.
c.
The storage capacity of a human is very high.
4
Computers perform arithmetic operations very fast and without mistakes.
d.
Humans can work continuously for a limited number of hours.
5
A computer cannot think.
e. Humans can think.
6
Computers can be classified by their configurations.
f.
7
Computers have limited storage capacity.
g. Each human being is different.
d
a. A human is not a machine.
Humans need food and water to work.
TYPES OF COMPUTERS Mainframe Computers A mainframe computer is a big, powerful, and expensive computer. Many people can use the power of a mainframe computer at the same time, using either a Personal Computer (PC) or a Dumb Terminal. A PC performs a lot of processing itself. A dumb terminal uses the mainframe computer to do all the processing and just shows the results on a screen. Large organizations, for example, banks and insurance companies, use mainframe computers.
IBM System z10 Mainframe Computer
10
ICT - Information and Communication Technology
Minicomputers Like mainframe computers, minicomputers are multi-user computers. They are very powerful and expensive. Mainframes and minicomputers are used for very similar purposes. Middle-sized companies use minicomputers. As microcomputers developed in 1970s and 1980s, minicomputers filled the mid-range area between low powered single-user microcomputers and high capacity multi-user mainframes. Since microcomputers have become more powerful and the PC networks emerged in 1980s and 1990s, the minicomputers role has been filled by microcomputers.
Supercomputers A supercomputer is a mainframe computer that is incredibly powerful and has a very large capacity for processing data. Supercomputers are often used by the military services. They are also used for such research as weather forecasting, in which a huge amount of data must be processed rapidly. Cray-2 was the world’s fastest computer in the 1980s. It was used by U.S. Departments of Defense and Energy for nuclear weapons research, by NASA’s Ames Research Center and by universities and corporations worldwide for different purposes.
Data General minicomputer
IBM Sequoia, IBM Roadrunner, IBM Blue Gene, and NEC Earth Simulator are the world’s fastest computers.
NEC Earth Simulator Supercomputer
IBM Sequoia 2012 - The world’s fastest supercomputer
Microcomputers Microcomputers are usually used only by one person at a time. An IBM PC and Apple Macintosh are two kinds of microcomputers. There are desktop, laptop, palmtop, tabletop, pocket, tablet, and netbook models of microcomputers. The Gartner information technology research and advisory company reported that the one billion personal computers in the world in October 2008 double by 2014 Chapter 1: Introduction to Computers
Apple iPhone pocket PC
11
Asus EeePC Netbook
Microsoft multi-touch surface tapletop PC
Toshiba Portege laptop
HP Pavilion desktop PC
Asus Eee Top touch screen PC
Form a working group with 4 students. Each student should explain a type of computer.
THE HISTORY OF COMPUTERS John von Neumann (1903 – 1957) was a Hungarian American mathematician who made major contributions to a vast range of fields, including set theory, functional analysis, quantum mechanics, continuous geometry, game theory, computer science, numerical analysis, and statistics.
12
The electronic computer industry has developed faster than any other industry in history. The first electronic computer was called the ENIAC (Electronic Numerical Integrator And Calculator). It was built at the University of Pennsylvania in 1943, and it was used for military calculations, for weather forecasting, and for atomic energy calculations. It weighed 30 tons and filled a big room. At 11:45 PM on October 2, 1955, ENIAC was shut down. Dr. John Von Neumann invented a technology for program storage at the University of Princeton in 1945. This technology allowed a computer to store a program in memory. People could change the program for different purposes. Dr. John Von Neumann’s computer made it possible to develop the computers we use today. ICT - Information and Communication Technology
The Main Periods in the History of Computers The history of computers has five main periods. They show how the technology that computers use for processing data has changed and developed.
1. Vacuum Tubes (1930–1958) The first computers used vacuum tubes to make calculations. A vacuum tube is a device used to amplify, switch, modify, or create an electrical signal by controlling the movement of electrons in a low-pressure space. It looks and behaves like a light bulb. It generates a lot of heat and has a tendency to burn out. The ENIAC was a vacuum tube computer. It weighed over thirty tons and consumed 200 kilowatts of electrical power. It had around 18,000 vacuum tubes that constantly burned out. Different types of vacuum tubes
2. Transistors (1959) Transistors replaced vacuum tubes because they were smaller, faster, and more reliable and used less energy. The transistor is considered by many to be the greatest invention of the twentieth century. It is the key active component in practically all modern electronics. Invitation of the transistor made it possible to produce integrated circuits, make personal computers, and fly spacecrafts and satellites.
Different types of transistors
3. Integrated Circuits (1965) Integrated circuits (microchips) use semiconductors to make complex circuits for data processing. Their invention was a big development for the computer industry. Big boards with transistors that took up a lot of space were replaced with small boards that reduced the size of computers and made them more reliable and less expensive.
Different types of microchips
Chapter 1: Introduction to Computers
13
4. Microprocessors (1971) A microprocessor incorporates most or all of the functions of a central processing unit (CPU) on a single integrated circuit. The computer company Intel introduced its first microprocessor in 1971. It was a 4-bit processor and was used for electronic calculators. Microprocessors allow computers to perform more accurate operations in less time. A microprocessor may contain millions of transistors. An AMD dual-core Athlon Processor has 154233 millions transistors, and an Intel Pentium D has 230 million transistors.
Using a PC
Different types of microprocessors
5. Personal Computer (1981) The computer company IBM introduced its first personal computer (PC), called the Datamaster, in 1981. PCs are made for individual use, and are intended to be operated directly by end users, with no intervening computer operator. The Datamaster
Form a working group with 5 students. Each group member should explain a period in the history of computers.
Important Inventions in the History of Computers zz3000 BC: People began to use an abacus for calculations.
An abacus
14
zz1642: Blaise Pascal made a mechanical calculator (for addition and subtraction) for his father to calculate taxes. These calculators (Pascalines) were well suited for the addition however, the nonreversible mechanism required a special technique for subtraction. ICT - Information and Communication Technology
zz1694: Wilhelm Gottfried Leibnitz (1646-1716) successfully developed a calculator. It was designed in 1673 but it was not completed until 1694. The calculator could add, subtract, multiply, and divide. Wheels were placed at right angles and could be displaced by a special stepping mechanism. The speed of calculation for multiplication or division was acceptable. zz1842: Charles Babbage made a machine (called a Difference Engine) that could solve more complex problems than Leibnitz’s calculator.
Pascal’s Calculator (Pascaline)
zz1890: Hermann Hollerith designed a computer that used punched cards. A punched card is a piece of stiff paper that contains digital information represented by the presence or absence of holes in predefined positions. zz1939: John Vincent Atanasoff developed the first electronic digital computer (Atanasoff–Berry Computer). The main ideas used in the ABC included binary math and Boolean logic to solve up to 29 simultaneous linear equations. The ABC had no central processing unit (CPU) but was designed as an electronic device using vacuum tubes for digital computation. It also used separate regenerative capacitor memory, a process still used today in DRAM memory. zz1943: J. Presper Eckert and John Mauchly created the ENIAC. People say that the ENIAC was the first real computer.
Difference Engine
Atanasoff–Berry Computer (ABC)
ENIAC
zz1945: John Von Neumann described a computer architecture in which data and program memory are mapped into the same address space (storedprogram technique). This group of machines included EDVAC and UNIVAC, the first commercially available computers. zz1958: Seymour Cray started to use transistors in computers. He designed a series of computers that were the fastest in the world for decades and founded the company Cray Research which built many of these machines. Cray is called “the father of supercomputing.”
Cray-1 Supercomputer 1976.
Chapter 1: Introduction to Computers
15
zz1964: IBM used integrated circuits in the IBM 360 computer. It was the first family of computers making a clear distinction between architecture and implementation, allowing IBM to release a suite of compatible designs at different price points. Intel 4004, The first CPU.
IBM 5150
zz1971: Intel introduced the first microprocessor (Intel 4004). It was a 4-bit CPU. Today’s 64-bit microprocessors are still based on similar designs. zz1975: The first microcomputer, called the Altair 8800, was introduced by MITS (Micro Instrumentation and Telemetry Systems). The MITS Altair 8800 was based on a 2 MHz Intel 8080 with 256 bytes standard RAM. User interface was through the octal front panel switches. zz1981: IBM introduced its first PC, IBM 5150. The first IBM PC ran on a 4.77 MHz Intel 8088 microprocessor. The PC came equipped with 16 kilobytes of memory, expandable to 256k. The PC came with one or two 160k floppy disk drives and an optional color monitor. The price tag started at $1,565.
The Altair 8800 microcomputer
zz1984: Apple introduced the first Macintosh, Macintosh 128K. It was the first commercially successful personal computer to feature a mouse and a graphical user interface rather than a command line interface.
Mac 128 K
Find an abacus and learn how it is used. Use your abacus to perform the following calculations. Operation 3+4
Result 7
Operation
Result
8+9
15+27
85+145
1853+3945
2*3
9*7
15*45
6-4
60-15
6/4
97/12
Blaise Pascal, Wilhelm Gottfried Leibnitz, Charles Babbage, Hermann Hollerith, John Vincent Atanasoff, J. Presper Eckert, John Mauchly, and Seymour Cray made great contributions to the development of modern computers. Learn their life stories and find out what they had in common, such as interests, difficulties in their lives, personalities and so on. 16
ICT - Information and Communication Technology
Computer technology has undergone a great development in sixty years. There is a tremendous difference between the first generation of computers and current computers. We have listed some characteristics of past and current computers. What do you expect from future computers? What kinds of capabilities do you think they may have in the future. Complete the table below with your predictions.
Past Technologies
Current Technologies
Future Technologies
Expensive
Cheaper
..........................................
Difficult to use
Easy to use
Slow
Fast
..........................................
Small storage capacity
Large storage capacity
Consumes more energy
Consume less energy
..........................................
Text-based interface
Graphical user interface
Bulky
Portable
..........................................
Data entry with keyboard
Many input devices: keyboard, mouse, touch screen, voice and so on.
No global network
Connected to other computers with Internet Multimedia
Chapter 1: Introduction to Computers
.......................................... .......................................... .......................................... ..........................................
..........................................
..........................................
..........................................
..........................................
17
COMPUTERS IN EVERYDAY LIFE Communication The Internet has made big changes in communication. It is a worldwide network of information resources and a powerful communication tool. Today, people can send e-mails, voice messages, and video clips to each other in seconds. They can also have typed conversations (chat), voice chat, and video conferencing with other Internet users all over the world.
There are nearly half a billion Windows Live users in the world.
The most used Internet communication tools are Electronic mail (web-based e-mail programs such as Hotmail, Yahoo mail, or Google mail, client-based mail such as Outlook Express), Internet forums, newsgroups, and real-time communication such as Windows Live Messenger or Yahoo messenger.
Education A scientific investigation has shown that education will be quite different in the near future with CBET (computer-based education and training). The research shows that CBET contributes to education in the following ways: zzImprove the quality of education. zzPersonalize education. zzDistance learning opportunities. zzHelp students to learn faster. zzHelp students to study in groups easily. zzHelp students to obtain information faster, more easily, and more cheaply. A digital library contains thousands of books.
zzSupport lifelong learning. zzUnlimited source of information. zzMake administration tasks easier in schools (e.g.,preparing a timetable for a school in just a few minutes). zzHelp parents track their children’s grades using the Internet. Computer-based learning requires instructional software. Instructional software is commonly used as follows:: zzTutorials present information and guide the learner. zzHypermedia programs allow learners to choose their own paths through the materials. zzDrills help users to practice for fluency and retention. zzSimulations allow users to operate freely and safely within a constrained environment.
E-learning (online training) is an alternative to traditional classroom training.
18
zzGames can be used to practice information in a competitive manner, may be used as a discovery environment, or may be used to integrate learning across a number of subject areas. ICT - Information and Communication Technology
zzGraphics tools can be used to support drawing in art or graphing in math. Calculations tools support science education. zzTests are used to assess what has been learned. zzWeb-based learning can be combined with other methodologies. It is most often used with hypermedia methodology.
Astronomy and Space Technology Astronomy and space technology need complex and precise calculations. Without computers, it would have been impossible for humans to go into space; to put satellites in orbit; and to study and follow planets, stars, comets, and meteors. Mistakes made by programmers or errors in computer systems have caused big losses in space work. For example, some years ago, space scientists lost the satellite Clementine in space because of a mistake in a computer program.
A satellite control center
Press and Publishing The use of page layout software on a computer (desktop publishing - DTP) allows publishers to produce high quality printable documents. Preparing books, newsletters, and magazines has become easier with computers. Writers, designers, and publishers can prepare and store their work on computers.
Authoring a book in QuarkXPress
Chapter 1: Introduction to Computers
19
Entertainment Many people use computers to play games, listen to music, watch movies, or share jokes with their friends. Multimedia computers are special computers for listening to music and watching movies. There are also special game computers such as, PlayStation, Dreamcast, and Xbox.
Engineering, Architecture, and Design Playing a video game
Engineers can prepare plans quickly and easily using CAD (computer-aided design) programs. They can print their plans from a computer and share them with other people.
Finance and Accounting Finance and accounting need fast and accurate calculations. Computers help companies to manage money and make good financial decisions.
Banking
A 3-D house design
Banks benefit from computer technology more than any other kind of company. Banks can store account information and perform banking operations using computers. Bank customers can use a computer to access their bank accounts from home. Automated teller machines (ATM) online and mobile banking help banks to the number of human tasks and allow customers to do their banking without going to the bank.
ATM banking
Employees work in front of computers in a bank . POS (Point of Sale) machine
20
ICT - Information and Communication Technology
Biology and Medicine Today, computers control almost all of the medical machines used in hospitals and for research. These machines help discover and cure illnesses much faster. For example, the Human Genome Project is an important research project that is using computers to develop a map of the human genome. It is a global, long-term research effort to identify the estimated 30000 genes in human DNA.
Military Services The military services use very powerful computers to control missiles and satellites and make decisions about military targets. They also use computers to train airplane pilots with special simulation programs.
Monitoring a patient A plane simulator
Find five people who use computers at work. Complete the table with the information you find. Name & Surname John Smith
Job Teacher of English
Uses a computer for... Keeping a list of students, with their grades, absences, and comments. Preparing presentations, quizzes, and exams. Showing visual materials in lessons.
MEASURING DATA (BITS AND BYTES) Understanding Data Data (the plural of datum) are anything in a form suitable for use with a computer. Whatever a computer receives as an input is data. Data are raw facts without any clear meaning. Computers process data and generate information. All data stored and processed by computers are in the form of whole numbers. The purpose of the numbers becomes clear after they are interpreted and displayed by software. Chapter 1: Introduction to Computers
Data are any sort of raw fact. Information is a usable form of data, usually processed in some way. It is data plus interpretation. If the pieces of a puzzle are data, then the completed puzzle are information. 21
The apple.bmp File Part of the data stored in the computer for the file apple.bmp
Decimal and Binary Number Systems Since childhood, we have learned to do our computations using the numbers 0 - 9, the digits of the decimal number system. In fact, we are so accustomed to working with decimal numbers that we hardly think about their use. Considering the widespread use of this system, why should anyone bother to study the binary number system? The answer is found in something that is almost as widespread as decimal numbers: computers. Every computer processor is made of millions of tiny switches that can be turned off or on. Because these switches have only two states, it makes sense for a computer to perform its computations with a number system that has only two digits: the binary number system. These digits (0 and 1) are called bits and correspond to the off and on positions of the switches in the computer processor. With only these two digits, a computer can perform all the arithmetic that we can with ten digits. We measure computer information (data) in bits and bytes. Bit is short for binary digit. It is the smallest unit of information that a computer can understand. One bit represents a 1 or 0 digit in a binary numeral or a true or false logical condition. A bit is represented physically by high or low voltage in a circuit or a small magnetized spot on a disk. Byte is short for binary term. A byte usually contains eight bits. It can represent a single character, such as a letter, a digit, or a punctuation mark. Because a byte represents only a small amount of information, we usually measure amounts of computer memory and storage in Representing a signal with binary and decimal numbers
zzkilobytes (one kilobyte is 1024 bytes), zzmegabytes (one megabyte is 1048576 bytes), or zzgigabytes (one gigabyte is 1073741824 bytes).
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ICT - Information and Communication Technology
In Bytes
In Bits (Power Notation)
In Bits
1 byte
23 bits
8 bits
1 kilobyte (KB)
210 bytes
1024 bytes
1 megabyte (MB) 220 bytes
1024 kilobytes
1 gigabyte (GB)
230 bytes
1024 megabytes
1 terabyte (TB)
240 bytes
1024 gigabytes
1 petabyte (PB)
250 bytes
1024 terabytes
1 exabyte (EB)
260 bytes
1024 petabytes
Converting a Decimal Number to Its Binary Equivalent To convert a decimal number to its binary equivalent, repeatedly divide the decimal number by 2, the base of the binary system. Division by 2 will either give a remainder of 1 (dividing an odd number) or no remainder (dividing an even number). Collecting the remainders from repeated divisions will give the binary answer. Consider the decimal number 178. The steps below show how to convert this number to binary using repeated division. Reading remainders from right to left, the final answer is 10110010. Remember that the first division gives the least significant digit of the answer, and the final division gives the most significant digit of the answer. Also, the result of the final division is always 0.
Converting a Binary Number to Its Decimal Equivalent To find the decimal value of a binary number, simply calculate the value of each binary digit and then sum these values. To convert the binary number to decimal, calculate the position value for each binary digit and then sum these values. Consider the binary number 10110010. The following chart shows how to calculate the position values and sum them up to get the decimal number. Chapter 1: Introduction to Computers
23
27
26
25
24
23
22
21
20
128
64
32
16
8
4
2
1
1
0
1
1
0
0
1
0
128
0
32
16
0
0
2
0
Positions values Binary digits Products Decimal Number
128+0+32+16+0+0+2+0 = 178
Octal Numbers and Hexadecimal Numbers While the binary number system is very important because of its connection with computers, it is not the only number system of importance. Two other number systems frequently seen are octal numbers and hexadecimal numbers. The octal number system is a base-8 number system and uses the digits 0 - 7 to represent numbers. The hexadecimal number system is a base-16 number system and uses the digits 0 - 9 along with the letters a - f to represent numbers. The table below shows a comparison of the first 16 numbers in the binary, octal, decimal, and hexadecimal number systems. Binary
You can use Windows Calculator or some other calculator programs to convert the values between different number systems.
24
Octal
Decimal
Hexadecimal
0000
0
0
0
0001
1
1
1
0010
2
2
2
0011
3
3
3
0100
4
4
4
0101
5
5
5
0110
6
6
6
0111
7
7
7
1000
10
8
8
1001
11
9
9
1010
12
10
A
1011
13
11
B
1100
14
12
C
1101
15
13
D
1110
16
14
E
1111
17
15
F
Base 2
Base 8
Base 10
Base 16
ICT - Information and Communication Technology
TAKING CARE OF THE COMPUTER There are various things that you can do to help prolong the life of your PC, both its hardware and software. It is always a good idea to keep your computer clean. A clean computer runs faster and lasts longer. Treat your computer gently; do not hit the keyboard keys too hard. Never put anything except your disks into the disk drives. A good practice is not to eat or drink near your computer.
Clean Out the Dust One of the most common causes of overheating is dust and dirt. So you need to keep your system clean, inside and out. This cleaning can be done with a vacuum cleaner or a can of dust remover. Monitor Cleaning Dirt, dust, and fingerprints can cause the computer screen to be difficult to read. CRT monitors have a glass screen and are cleaned in pretty much the same way as any other glass in your home or office. Flat screen monitors, however, require a bit of special care when cleaning. Their displays are much more sensitive and are easily scratched and damaged. Follow the steps below to clean your LCD monitor safely: zzTurn off the monitor. If the screen is dark, it will be easier to see the areas that are dirty or oily. zzUse a dry, soft cloth (Not paper towels, toilet paper, tissue paper, or something like your shirt) and very gently wipe the screen. A great choice would be the microfiber type of cloth used to clean eyeglasses. zzIf the dry cloth did not completely remove the dirt or oil, do not press harder in an attempt to scrub it off. Pushing directly on the LCD screen can often cause pixels to burn out. If necessary, use a vinegar mixture or special LCD cleaner spray to remove the difficult spots.
LCD monitor cleaning kit
Keyboard Cleaning Keyboards collect the oils from hands. Cleaning your keyboard can get rid of sticky keys. Follow the steps below to clean your keyboard: zzDisconnect the keyboard from the back of the computer. zzHold the keyboard upside down over a desk and smack the bottom of the keyboard to knock out any loose dirt or dust. zzLay your keyboard on a table. zzUse compressed air or a brush to get out any loose debris. zzUse isopropyl rubbing alcohol or a cleaner solution to dampen a cloth and clean the surface of each key along with the surrounding areas of your keyboard. This step should restore the natural brilliance of your keyboard! zzReconnect the keyboard to the back of the computer. Chapter 1: Introduction to Computers
Cleaning a keyboard with a brush
25
Mouse Cleaning You hold onto your mouse every day, oils from your hand get onto the mouse and over time will discolor the plastic of your mouse. Optical mice quickly replaced the traditional mechanical ball mouse because they are more sensitive, the mouse pointer works on uneven surfaces without a mouse pad, and there’s no internal cleaning is required because there are no rollers or rotating wheels. Follow the steps below to clean your optical mouse: Bottom view of an optical mouse
zzDisconnect the optical mouse from the back of the computer. zzDampen one of your lint-free cloths with some isopropyl rubbing alcohol. zzClean the outside of the mouse with the cloth. If there is a smudge on the lens area, gently clean with a plain cotton swab. zzReconnect the optical mouse to the back of the computer. Case Cleaning Almost any type of household cleaner can be used to clean the outside of the computer case. zzTurn off your computer. zzRemove the side cover of the computer case, exposing the motherboard and other hardware components. zzInspect all cables and connections. If you come across any cables that are damaged in any way, you should immediately replace them.
Using an air can to evacuate the dust
zzGet out the compressed air and shoot the canned air at everything in your computer. Pay special attention to the heatsink and fan on top of your processor. This area collects a lot of dust. A vacuum may help suck out the dust while you knock it loose with the compressed air. If you choose to use a vacuum, be careful not to vacuum anything in your computer. zzIf you notice dust in the PCI and AGP slots of your motherboard, it may be wise to remove each add-on card and shoot some compressed air into the slots to break away the dust. zzIf your case has an air filter, remove it and run it through warm water to remove the dust. To dry it, simply use a cloth (lint-free if possible) and gently dab away the excess water. Place the filter back into the case. zzReplace the side cover of the computer, but check first that no cables are lying next to any fans. Fasten the cover and restore the power.
Keep Your PC Cool You should always make sure that you keep your computer in a well ventilated area and away from direct sunlight and heat sources. By doing so you help keep the PC cool and, therefore, will prolong the life of your hardware.
Fans collect dust more than any other components in the case.
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ICT - Information and Communication Technology
Buy Quality Hardware When you buy new components for your PC, try to get good quality parts. If you get components from respected manufacturers you can be sure that you will get good technical support and the parts will be well made and not cause problems with other hardware.
Get Power Protection One of the saddest things is that many PCs are not surge protected. Surge protectors are a good investment: They protect your PC from voltage spikes. A surge protector attempts to regulate the voltage supplied to an electric device by either blocking or shorting to ground voltages above a safe threshold.
Get an Anti-Virus Program A computer virus is a computer program that can copy itself and infect a computer without the permission or knowledge of the user. Viruses can cause your computer to be slow or not work at all. You should always have a good virus scanner installed and keep it up to date. Some well-known virus scanners are Norton, McAfee, and AVG. AVG is free for home users.
A five-outlet surge protector
Scan for Other Malware Other malware can include spyware, adware, key loggers, and trojan horses. These pieces of software can get installed without your knowledge when you install another program or visit a website. They can cause your PC to slow down considerably. Microsoft Windows Defender, Spybot Search & Destroy, and Adware are well known malware scanners.
Run the Defragmenter Utility Defragment your hard disks at least once every month or two. The defragmenter will help ensure that your files are located at the right place on the hard drive and should boost the overall speed of your computer. It does this by physically organizing the contents of the disk to store the pieces of each file close together and contiguously. To run the Windows defragment program, in Windows Explorer, right click on the drive’s icon, select Properties -> Tools -> Defragment Now.
Clean Up Old Files If you install or uninstall software frequently, it can leave many unwanted files in temporary and system folders. The Disk Cleanup utility erases temporary files and compresses old files to free up disk space on your hard drive.
Chapter 1: Introduction to Computers
Defragmentation increases the performance of your PC.
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HEALTHY COMPUTER USE When you use a computer, your body can get tired. Follow these rules to stay comfortable and healthy in front of your computer.
Make Yourself Comfortable zzPut the computer on a flat table at a comfortable height and distance to avoid hurting your eyes; make sure that the display is a bit below your eye level. Proper way of working on computer
zzPut the computer directly in front of you when you work. Make sure you have enough space to operate the different parts of the computer (keyboard, mouse, etc.) easily. zz If you use a paper holder, put it at about the same height and distance from you as the monitor. zzSet your chair height so that the keyboard is at (or slightly below) the level of your elbow. You should be able to type comfortably with your shoulders relaxed. zzYour knees should be slightly higher than your hips. If necessary, use a foot rest to raise your knees. zzSet the back of your chair so that it supports the lower part of your spine. zzSit straight so that your knees, hips, and elbows are at about 90 degree angles when you work. Do not lean forward or back too far. zz If possible, use soft, indirect lighting in your computer work area.
Take a Break zzChange your position often. If you use a computer for a long time, stand up and stretch your wrists, hands, and legs regularly. zzTake frequent short breaks (for example, two or three minutes every half hour) instead of one or two long breaks. Stretching shoulder and arms
Eyes and Eyesight zzWorking at a screen for a long time without a break can have effects similar to reading or writing uninterruptedly and may make your eyes feel tired or sore. zzEvery fifteen or twenty minutes, look at an object that is far away to avoid hurting your eyes with too much close work. zzPut the computer so that sunlight or bright indoor light does not reflect off the screen and hurt your eyes. zzHave regular eye examinations. Visit a doctor if your body hurts or aches because of too much computer work.
Take short breaks when use a PC for a long time.
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ICT - Information and Communication Technology
BUYING A COMPUTER Purchasing a home or business computer is a difficult decision to make. You must decide what to look for when buying a computer and what software you need for e-mail, basic Internet usage, word processing, and so on. Computer prices have dropped a good deal over the past few years, and the computing power you get for your money is increasing. Choosing a computer to meet your minimum needs on a limited budges requires some crucial decisions. If you buy a very cheap computer, you might not be able to run all your programs. However, you should not pay extra money for power or parts that you probably will not use. Keep in mind that computers are always changing. Today‘s latest computers may be out of date in a few years, and your computer will no longer be good enough for you. Below is a listing of helpful suggestions for what to look for and ask about when purchasing a home or business computer.
Pay only for what you need.
Your Needs Your computing needs determine the type of computer you need to buy. First of all, think about what you would like to accomplish with your new computer. Have you been dreaming of starting a new website with Flash? Are you a casual Internet user? Do you play games online, or do you play the latest retail games when they are released? Do you need a portable computer or a desktop? If you want to play music and games, you should buy a multimedia computer. To use the Internet, your computer needs a modem or network connection.
Windows vs. Mac From a beginner’s perspective, both Windows and Mac PCs have pointand-click interfaces that are fairly easy to use. Both will take you to the same Internet, and enable you to send and receive e-mail. Both offer word processing, and the documents they create are interchangeable. Because Windows-based computers make up 90% of the market, they are less expensive.
Desktop vs. Laptop The main benefit of a laptop is the portability, which can be a huge benefit, allowing you to take your computer to and from work, on planes, on vacation, and practically anywhere else. However, in general, laptops are far more expensive than desktop systems. For the price of an average laptop, you could purchase a much more powerful desktop. If you need a portable computer for wireless communication, access to the Internet, and everyday tasks, a netbook can be a good cheap solution for you.
Chapter 1: Introduction to Computers
29
Another major drawback of laptop is that their parts are proprietary so if your laptop breaks, only the company that made it will be able to fix it, and after the warranty expires, it will cost a lot.
When Choosing a Laptop The following three important developments can be used in selecting a laptop and differentiating between a laptop and a desktop computer. zzThe use of dual core systems: Dual core systems are considered advanced systems, with dual core chips built by Intel and AMD. Dual core systems allow for fast and heavy graphics computing and will meet your needs for computing speed or most purposes and for heavy gaming in which realistic graphics are required. They also come with better graphics card such as the ATI Mobility Radeon X800 XT graphics card. zzWireless modem and cellular phone modem: The feature of a cellular phone modem in a laptop will ensure you can be connected either by wireless modem or by the cellular phone modem. This feature is very useful for mobile computing. zzSufficient battery life: Consider the battery life of your laptop. Because you will be moving around with the laptop, a battery life of 2 hours or more will be sufficient most cases. You really do not want to have your computing use interrupted when the battery runs out in the middle of an important computing session.
Hardware CPU The speed of the microprocessor has a big effect on your computer’s speed. However, other parts of the computer (for example, the RAM, disk drives, and the mainboard) also affect the speed of a computer. Choose good quality parts if you want good computer speed. Intel and AMD are two major CPU producers. AMD processors are usually cheaper while Intel processors are considered higher quality and more reliable than AMD microprocessors. Choosing a processor is an exercise in predicting the future. A dual core processor with at least 2.00 GHz speed and a 2 MB cache is recommended.
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ICT - Information and Communication Technology
Memory (RAM) Your computer should have enough memory to run your applications. Make sure that it is possible to add new RAM modules or replace existing RAM modules with larger ones. Do not buy a computer with less than 2 GB RAM. Hard Disk The hard drive is your permanent file storage. All of your personal files, such as word processor documents, photos, music, and e-mails are stored here, in addition to software packages and the operating system. Your hard disk should be big enough to store all your programs, documents, pictures, music, and movies. A 320 GB hard disk with 16 MB or more cache is a good choice. Monitor Find a monitor size to suit your needs. The larger the monitor, the less eyestrain and scrolling. For design work, you might prefer a bigger screen. Wide screen and square monitors are available. The wide screens are useful for watching movies and desktop publishing, but for document work (word processing, programming, etc.), square monitors are better. Choose an LCD monitor 17 inches or larger. Disk Drives Floppy disks are not used any more. CD-ROM and DVD-ROM are the most popular types of disk drives. Your computer should read and write CDs and DVDs. You may prefer a combo drive to save space in your computer case. The new Blu-Ray drives are also available but expensive. Sound and Video Most computer users will find that standard sound cards will suit their needs. However, advanced sound cards will increase the number of speakers that can be used and, for some games and programs, the sound quality and capabilities.
Wide and square screen aspect ratios.
Software Your computer should be able to run the programs that you need at the moment and in the near future. Good software will help you to get the best performance from your computer. Most of the software you need will come pre-installed on your new PC. Windows comes with Internet Explorer (for web browsing) and Outlook Express (for e-mail). Many PC systems include a word processor, such as Microsoft Word. If your computer does not come with any of these, you can find free office software, such as OpenOffice,that works just as well. Look for a computer that comes with anti-virus software pre-installed. If yours does not, check with your Internet service provider to see if it offers anything for free. Another option, you can download a free anti-virus package such as AVG or Avira to replace the one that comes with your system when the free trial period expires. Chapter 1: Introduction to Computers
31
Service, Support and Warranty zzService is an important consideration when purchasing a computer. What type of service is offered? Will a technician come to your location or will you take the computer to the repair center? Is the service for the complete time of the warranty? How fast will the service be completed? If that time frame is not accomplished, what is the company willing to do. For example, is it willing to loan you a computer? zzTechnical support is a very important consideration for most users. When looking at the support options for a computer, you should check whether the support is available 24 hours, 7 days a week and holidays, and what support options are available, for example, phone, e-mail and chat. zzThe warranty should cover both hardware and software issues. A computer should be considered if it has at least a one-year warranty.
24/7 support is important for many users.
List the purposes for which you need a computer and configure your computer.
My Needs? .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. ..................................................
Device Case Main Board CPU Hard Disk RAM CD/DVD Driver Video Card Sound Card Network Card Modem Monitor Keyboard Mouse Speakers Microphone
Description
Price
Total Price 32
ICT - Information and Communication Technology
Find the words in the word search puzzle. COMPUTER
MAIL
MONITOR
MEGABYTE
CPU
ENIAC
SOFTWARE
CALCULATION
RAM
TRANSISTOR
HARDWARE
MAINFRAME
ABACUS
BIT
PC
PASCAL
BYTE
CAD
DISK
KILOBYTE
B I T A N S U C A B A E N P U Y T D E V I T C E F O D A C R T C H Q C O R P X U K G A A K E P A M S H A L O K S L S M S Y U R O T I N O M R C A N D I O M D A T Y S P E U S O F M D E M W E M A I L L R S E B U R T E A M F S S A B A D P S I
I
Y G R A R E T U P M O C R E V B A E R Z I O Y N O S O D P E O B T
F O E R A W T
F O S A R
L Y E N I A C Z M B
I L D S A
I T A I B R E M M A U M I C E K E M A X I B I O S M A N A Y C E N M G A D Z O B O O K L M
Chapter 1: Introduction to Computers
33
ICT provides many job opportunities. A career in ICT is not for everyone, but for those interested in working in this area. The following is a list of roles filled by people working in ICT. Learn about the roles and responsibilities of each one and complete the table. People Technician
Description Keeping computers and computer systems running effectively. Diagnosing and solving hardware and software problems. Good knowledge of hardware and operating systems.
Programmer
Data Entry Operator
Web Designer
Project Manager
Software Engineer
Support Staff
Computer Engineer
Network Administrator Sales Representative Multimedia Specialist
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ICT - Information and Communication Technology
1. 101001 in the decimal system. 2. A device that allows you to input information into your computer.
3. A base-2 number system. All numbers are
represented as a sequence of zeros and ones. 4. A small program, commonly embedded in another program, that infects programs and causes them to malfunction. 5. The most powerful type of computer. 6. A numeral system with ten as its base. 7. A hand-held input device that moves the cursor on the screen and selects items when the user moving on a flat surface and clicks its buttons. 8. The abbreviation of personal computer. 9. A set of instructions that tell a computer what to do and how to do it. 10. The most commonly used output device for Chapter 1: Introduction to Computers
displaying text and graphics on a computer.
11. The central board of the computer. 12. A unit of information that is equal to 1024
megabytes. 13. The first real computer. 14. A kind of microcomputer. 15. A sequence of 8 bits, which can be used to represent a character. 16. The heart and brain of the computer that receives data input, processes information, and executes instructions. 17. The physical parts of a computer system. 18. Successor of the vacuum tube.R 19. Process of reorganizing files on a disk to make segments contiguous and to recover wasted space between segments. Improves performance and saves disk space. 35
Test Questions 1. Which one is wrong for computers?
a. Computers don’t forget. b. Computers are fast machines. c. Computers are electronic machines. d. Computers can think like human beings. e. Computers are programmable.
2. Which one is different from the others?
a. Mainframe computers b. Minicomputers c. Microcomputers d. Supercomputers e. GameBox
3. Which one is not a main periods in the history of computers?
a. Vacuum tubes b. Transistors c. Notebooks d. Integrated circuits e. Personal computers
4. When did Apple introduced the first Macintosh?
a. 1964 b. 1971 c. 1981 d. 1984 e. 1990
5. Which statement is incorrect? a. Mistakes made by computers have caused big losses in space work. b. Multimedia computers are special computers for
36
storing account information and performing banking operations. c. The Human Genome Project is an important research project that is using computers to develop a map of the human genome. d. Preparing books, newsletters, and magazines has become easier with computers. e. Computers are the excellent for storaging of patientrelated data in medicine.
6. Convert 100012 binary number to its decimal equivalent
c. You should run the Disk Cleanup utility once in a while to clean things up. d. Computers are notorious for accumulating dust. e. Computers are vulnerable to viruses
9. Every ………………….. minutes,
look at an object that is far away, to avoid hurting your eyes with too much close work.
a. 10 b. 15 c. 20 d. 30 e. 60
or or or or or
15 20 30 60 90
10. Which statement is incorrect??
a. 1110 b. 1710 c. 4510 d. 12710 e. 123710
7. Convert 102310 decimal number to its binary equivalent
a. 11110111112 b. 10101010102 c. 11111111112 d. 10000111102 e. 10000111112
8. Which statement is incorrect? a. The keeping your PC cool will help ensure that your files are located at the right place on the hard drive. b. You should always make sure that you keep your computer in a well ventilated area.
a. Your computer should have enough memory to run your applications. b. Find a monitor size to suit your needs. If you want to do multimedia design, you might prefer a smaller screen. c. Your hard disk should be big enough to store all your programs, documents, pictures, music, and movies. d. If you want to listen to music, watch movies, play games, or make your own music or movie, you will need a high quality sound and video cards, and speakers. e. A UPS protects the data on the computer from being lost if the power goes out.
ICT - Information and Communication Technology
Introduction The physical parts of a computer are called hardware. In this chapter, we will examine the different types of hardware according to four groups: the system unit, input devices, output devices, and storage devices. The system unit contains the main components of the computer, such as the mainboard, CPU, RAM, graphics card, hard disk, disk drives, and power supply. It can also contain optional components such as a sound card or a network card. We use input devices to put data into the computer. The most common input devices are the keyboard and the mouse. Other types of input device are a scanner, joystick, light pen, touch screen, webcam, and digital camera. A desktop PC system
Output devices are the components that display results. A monitor, printer, plotter, and speaker are all output devices. Storage devices are used to store data permanently. A hard disk, floppy disk, CD-ROM, DVD-ROM, zip disk, flash memory, memory cards, and tape cartridge are examples of storage devices. Some hardware parts (such as the CPU, mainboard, RAM, power supply, keyboard, graphics card, and hard disk) are necessary for computer to work. Some parts , such as a modem and network card, are optional and simply increase a computer’s functionality.
The System Unit All of the main components of a computer are grouped together in the system unit. For instance, the system unit includes the computer system’s motherboard (including the processor), expansion cards (video card, sound card, network card, etc.), power supply, and items such as hard disks, and CD-ROM drives, and so on.
Chassis (Case) The chassis is the metal and plastic box that contains the system unit (mainboard, power supply, cooling equipment, hard drives, memories, optical drives, and any expansion cards). It protects the system from the outside world and helps to keep the system unit components cool. The closed design and good air flow inside the chassis are especially important for components such as the CPU and hard drive, which can get very hot when they are working.
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ICT - Information and Communication Technology
Cases can come in many different sizes or form factors. Currently, the most popular form factor for desktop computers is ATX. The ATX (Advanced Technology eXtended) form factor was created by Intel in 1995. It was the first big change in computer case and motherboard design in many years. There are some general and more specific classifications regarding all cases. The first classification is according to one of four basic types: towers, midtowers, mini towers, and desktops. Tower chassis usually stand vertically, whereas desktop chassis stand horizontally. Most standalone servers come in large towers, which sit upright and are generally very large to accommodate a large number of hard drives, cooling equipment, and dual processors. Some high-end workstations and gaming stations these days are enclosed by full towers. Mid-towers are like towers in that they stand upright but are generally smaller in depth, length, and height. The vast majority of computers these days are mid-towers or mini towers. The fourth class is the desktop. This is a computer that lies flat on the desk, usually with the monitor on top of it.
A PC with a desktop case
A PC with a midi tower case
Inside a tower case
Chapter 2 - Hardware
39
Power Supply The power supply is an electrical device that transforms the standard electricity supply (115-120 volts AC (alternating current) in the United States or 220 volts AC in Europe) into the lower voltages (3.3 or 5 to 12 volts DC (direct current) that computer systems require. Personal computer power supplies are measured in watts. They usually range from about 50 watts to 500 watts.
Power supply of a PC
Your PC’s power supply converts the 220 volt outlet alternating current to various direct current levels.
40
Uninterruptible Power Supply (UPS) A UPS is primarily used as a backup power source for the computer. It can keep a computer running for a while so a user can save work and properly shut down the computer when the power goes out. It also protects the computer against different power problems such as high voltage, low voltage, and frequency differences.
ICT - Information and Communication Technology
A UPS with a digital display
Proper use of a UPS
What is the total power usage of your computer? Calculate sum of the power usage of each component. Component
Power Usage in Watt
Monitor Motherboard CPU CPU fan Case fans Hard disk RAMs Video card Sound card Network card CD/DVD drive USB devices Total Power
Chapter 2 - Hardware
41
Mainboard The mainboard (also called the motherboard, or system board) is the biggest board inside your system unit. All the main components of your computer connect to the mainboard. The CPU, BIOS and chipset are normally situated on your mainboard along with all the other electronic components. The CPU executes computer programs, BIOS contains the first code that is run by the PC when powered on, and the chipset is a set of specialized chips (northbridge and southbridge) that control the flow of data throughout the motherboard. The storage devices, such as the hard disk and DVD drive, are attached to the mainboard via data cables. The expansion cards, such as the video card and RAM modules, are attached to the mainboard via the PCI and memory slots. The video and sound cards can be integrated into the mainboard (onboard). Mainboards are getting smaller as the components become more integrated. The well-known motherboard manufacturers are AsusTek, Intel, Giga-Byte, Micro-Star International, MSI, PC Chips, and Tyan Computer.
1 20-Pin ATX power connector
6
4
5
2 DRAM memory slot
7
3 IDE connector (x2)
3 2
4 Northbridge (with heatsink) 5 AGP slot
1
6 Southbridge 7 PCI slot (x5)
8
11
10
9
8 CMOS backup battery 9 Connectors for integrated peripherals (PS/2 keyboard and mouse, serial port, parallel port, USB (x6), ethernet, audio (x3)) 10 CPU socket 11 CPU fan and heatsink mounting points
A mainboard
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The ROM-BIOS (Read Only Memory-Basic Input Output System) zzThis chip is a special ROM microchip on your computer’s mainboard. It ensures that the BIOS will always be available and will not be damaged by disk failures. It also makes it possible for a computer to boot itself. Many modern PCs have flash BIOS, which means that the BIOS have been recorded on a flash memory chip, which can be updated if necessary. Because RAM is faster than ROM, many computer manufacturers design systems so that the BIOS is copied from ROM to RAM each time the computer is booted. On PCs, the BIOS software performs the following tasks: zzChecks the information stored in a tiny (64 bytes) amount of memory located on the CMOS (complementary metal oxide semiconductor) chip. The CMOS Setup provides detailed information particular to the system and can be altered as the system changes. The BIOS uses this information to modify or supplement its default programming as needed. zzConducts a power-on self-test (POST) for all the different hardware components (keyboard, display screen, disk drives, serial communications) to make sure everything is working properly. zzDisplays system settings. zzLoads the operating system from hard disk to RAM. zzActivates other BIOS chips on different cards installed in the computer. You can configure the BIOS by entering the CMOS Setup. To enter the CMOS Setup, you must press a certain key or combination of keys during the initial startup sequence. Most systems use “Esc,” “Del,” “F1,” “F2,” “Ctrl-Esc,” or “Ctrl-Alt-Esc” to enter setup. Once you enter the CMOS setup, you have the following options: zzSystem Time/Date: Set the system time and date. zzBoot Sequence: Set the order of devices the BIOS will try to load the operating system from. zzPlug and Play: Set to “Yes” if your computer and operating system both support it. This is a standard for auto-detecting connected devices. zzMouse/Keyboard: Configure the keyboard and mouse by using “Enable Num Lock,” “Enable the Keyboard,” “Auto-Detect Mouse” and so on. zzDrive Configuration: Configure hard drives, CD-ROMs and floppy drives. zzMemory: Direct the BIOS to shadow (copying the BIOS software to RAM) to a specific memory address. Security: Set a password for accessing the computer. zzPower Management: Select whether to use power management, and set the amount of time for standby and suspend.
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Different Types of BIOS Chips
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Phoenix – Award CMOS Setup screen
Any customized settings in the BIOS are retained when the PC is switched off because a CMOS battery keeps the CMOS chip with the data powered up. The CMOS battery is located on your computer’s motherboard.
CMOS Battery on the Mainboard
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System Buses A motherboard is the most critical part of a computer system. It consists of three major components: the BIOS (basic input/output system) chip, the CPU (central processing unit), and the system buses. Every component in the computer must be able to communicate with the CPU through the motherboard. This connection is done via a collection of copper or gold tracings attached to the motherboard. These tiny wires are called buses. Buses carry data and control messages between the components. A motherboard has the following buses connected to it: The Power Bus: Power for the system is distributed by the motherboard via a power bus that is connected to the power supply. Some components (especially disk drives) draw their power directly from the power supply instead of through the power bus. Other components, like PCI cards and USB devices, draw power directly from the power bus. zzThe Front Side Bus: The front side bus is a special high speed bus. It is designed especially to connect the CPU to components with which it must communicate very frequently, such as, RAM and the system’s video card. zzThe Back Side Bus: The back side bus is a special bus that allows communication between the CPU and the layer-2 cache, which is a device that offloads some specialized computing tasks to make the CPU operate more quickly. zzThe Peripheral Component Interface (PCI) Bus: The PCI bus is a slightly slower bus that connects many optional cards to the motherboard. Examples include sound cards, network cards, and custom manufactured external peripheral cards. There is a newer PCI standard, called PCI Express, which is designed to handle inter-card communication at multi-gigabit speeds. zzThe Universal Serial Bus (USB): Many external peripherals are connected to the system via the USB. zzFirewire Bus: Firewire is a special bus designed to operate very efficiently with cameras and other peripherals that require an extremely high speed, wired interface.
Buses on the motherboard
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Diagram of system buses
The Bus Arbitration (Chipset) The bus arbitration chipset is an integrated circuit on the motherboard. It controls how the mainboard buses are used. If two different devices try to use the same bus at the same time, it can cause a problem. The bus arbitrator prevents this problem. On a PC, the chipset consists of two basic parts: the northbridge and the southbridge. The northbridge connects directly to the processor via the front side bus (FSB). A memory controller is located on the northbridge, giving the CPU fast access to the memory. The northbridge also connects to the AGP or PCI Express bus and to the memory itself. The southbridge is slower than the northbridge, and information from the CPU has to go through the northbridge before reaching the southbridge. Other busses connect the southbridge to the PCI bus, the USB ports, and the IDE or SATA hard disk connections.
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CPU
AGP
RAM
Northbridge
Southbridge
PCI
Legacy
USB
BIOS
ISA
IDE
The bus arbitration of mainboard
Expansion Slots Expansion slots hold expansion cards (such as a video card, sound card, or network card) and connect them to the buses. Laptops and other portable computers use special expansion slots called PCMCIA slots, which accept small expansion cards called PC Cards. Common types of expansion slots are AGP, AMR, CNR, EISA, ISA, PCI, and VESA. AGP (accelerated graphics port) is a high speed connection used only by video cards, so there can be only one in a computer. It has direct access to system memory so that the computer’s memory can be used in addition to the video card’s memory. Chapter 2 - Hardware
An AGP slot
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PnP (plug and play) is a technology that lets operating systems automatically detect and configure most of the adaptors and peripherals internal and external to the PC.
The PCI (peripheral component interconnect) is developed by Intel Corporation. It has gained wide acceptance (even by Apple, in its PowerPC series). Intel created the PnP (Plug and Play) standard and incorporated it into the design for PCI. PCI originally operated at 33 MHz using a 32-bit-wide path. Currently, PCI-X (PCI Express) provides for 64-bit transfers at a speed of 133 MHz for an amazing 1-GBps (gigabyte per second) transfer rate. Most new motherboards use PCI slots only.
Three types of PCI expansion slots
Bus
Bus Speed (MHz)
Width (bits)
Bus Bandwidth (MB/sec.)
8-bit ISA
8
8.3
7.9
16-bit ISA
16
8.3
15.9
EISA
32
8.3
31.8
VLB
32
33
127.2
PCI
32
33
127.2
PCI
64
133
1 GBps
64-bit PCI 2.1
64
66
508.6
AGP
32
66
254.3
AGP (x2 mode)
32
66x2
508.6
AGP (x4 mode)
32
66x4
1,017.3
Bus specifications
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ATA and ATAPI Interfaces ATA (advanced technology attachment) is the real name for the mass storage device (such as hard disks, solid-state drives, and CD-ROM drives) interface, frequently called IDE (integrated drive electronics)or EIDE (enhanced IDE). It uses 16-bit parallel interface for controlling computer drives. ATAPI (advanced technology attachment packet interface) allows SCSI devices to be attached to the ATA interface. SATA (serial ATA) is a new standard for connecting hard drives into computer systems. As its name implies, SATA is based on serial signaling technology, unlike current IDE hard drives that use parallel signaling (PATA). The current SATA standard provides significant benefits over ATA in terms of convenience, power consumption, and most importantly, performance.
SCSI (small computer system interface) is a type of interface used for components such as hard drives, optical drives, scanners, and tape drives. The SCSI card fits into an internal PCI slot. SCSI devices are then connected to this card.
1 SATA Interface 2 ATA Interfaces
1
2
IDE and SATA connectors on the mainboard
IDE cable with one 40-pin connector in each end
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SATA cable
Peripheral Connectors Many newer motherboards have multiple connectors attached to the side for connecting peripheral or input/output devices. Examples of these ports are shown below.
1 Mouse PS2 socket 2 Keyboard PS2 socket 1
7
3 Serial port 4 Parallel port 5 Audio ports 6 USB ports
2
3
4
5
6
7 RJ45 network sockets
Main connectors on the motherboard
zzSerial Ports allow connection of items such as modems to the computer. Serial ports are commonly labeled COM1 or COM2. Serial ports are commonly used in such applications as industrial automation systems, scientific analysis, shop till systems and some consumer products. Network equipment often uses a serial console for configuration. Serial ports are still used because they are simple and cheap and their console functions (RS-232) are highly standardized and widespread. 50
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zzParallel Ports enables connection of items such as printers to the computer. Parallel ports are commonly labeled LPT1 or LPT2. Before the advent of USB, the parallel interface was adapted to access a number of peripheral devices other than printers. The earliest devices to use parallel ports were dongles used as a hardware key form of software copy protection. Zip drives and scanners were early implementations, followed by external modems, sound cards, webcams, gamepads, joysticks, and external hard disk drives and CDROM drives. Adapters were available to run SCSI devices via parallel. Other devices such as EPROM programmers and hardware controllers could be connected in parallel.
A dongle (hardlock) is a piece of hardware that attaches to a computer to make a piece of secured software run.
Parallel Port and USB dongles
zzThe PS/2 connector is used for connecting some keyboards and mice to a PC compatible computer system. Its name comes from the IBM Personal System/2 series of personal computers, with which it was introduced in 1987. zzThe USB (universal serial bus) is a serial bus standard for connecting devices to a host computer. USB was designed to allow many peripherals (printers, scanners, cameras, network cards, mp3 players, and external hard disk drives) to be connected using a single standardized interface socket and to improve plug and play capabilities by allowing hot swapping. That is, allowing devices to be connected and disconnected without rebooting the computer or turning off the device.
Internal Speaker An internal speaker is connected to the mainboard and allows the computer to sound error or warning beeps while it is running. The PC speaker today deals largely with low-level warning signals such as start-up errors.
The internal PC speaker
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Find out your computer’s motherboard specifications and complete the table below. Run Windows DirectX Diagnostic Tool (run dxdiag command from the command line) or download and use a third party system diagnostic software, such as aida32, Cpu-z, or Meltdown System Diagnostic to obtain the information you need about your system. Component
Description
Motherboard manufacturer Motherboard model Chipset BIOS name and version Front bus width and clock rate Name of the CPU Amount of L1 cache Amount of L2 cache Amount of physical memory Number of physical memory modules Amount of virtual memory (page file) Type of graphic interface
Visit a computer seller’s web site or get a price list of computer components and compare the different types of mainboards according to supported CPU, RAM, expansion slots, price, bus speed, and so on.
Central Processing Unit (CPU) A central processing unit (CPU) or processor is an electronic circuit that can execute computer programs. The CPU is one of the most important components inside your computer. It is like the brain of your computer, because it performs all the computer calculations. CPU speed is measured in gigahertz (GHz) and has an important effect on the overall speed of your computer. The main CPU manufacturers today are Intel, AMD (Advanced Micro Devices), and VIA Technologies. 52
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Inside a CPU A CPU is a complete computation engine fabricated on a single chip. It consists of a very small amount of very fast memory (cache) that is used both to queue commands (program instructions) and to contain data to work on (registers). The CPU contains an arithmetic logic unit (ALU) that processes commands and performs operation on various registers and memory locations.
1 L2 cache
7 1 2
8 9
2 Control unit 3 Instruction unit 4 Registries
3 4
5 L1 cache (instructions) 6 Input - output management unit
5 6
7 ALV 8 FPU 9 L1 cache (data)
CPU block diagram
zzCPU Cache: A CPU cache is a smaller, faster memory that stores copies of the data from the most frequently used main memory locations. When the processor needs to read from or write to a location in main memory, it first checks whether a copy of that data is in the cache. If so, the processor immediately reads from or writes to the cache, a much faster that than reading from or writing to main memory. Most modern desktop and server CPUs have at least three independent caches: an instruction cache to speed up executable instruction fetch, a data cache to speed up data fetch and store, and a translation look aside buffer used to speed up virtual-to-physical address translation for both executable instructions and data. zzCU (Control Unit): The CU controls operations of other parts of the CPU, such as determining the sequence of instruction to be executed and flow of data among all parts of the computer, interpreting instructions, regulating the timing of the processor, and sending and receiving control signals to and from peripheral devices. zzALU (Arithmetic Logic Unit): The ALU is a digital circuit that performs arithmetic and logical operations. It is a fundamental building block of the CPU of a computer, and even the simplest microprocessors contain one for such purposes as maintaining timers. The modern CPUs have inside them very powerful and very complex ALUs. Chapter 2 - Hardware
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zzFloating-Point Unit (FPU): The FPU is a dedicated execution unit designed for performing math functions on floating point numbers (any number other than an integer, such as 12,34). In most modern general-purpose computer architectures, one or more FPUs are integrated into the CPU. FPUs also perform arithmetic operations between two values, but they do so for numbers in floating point representation. zzRegisters: A register is a local storage area within the processor whose contents can be accessed more quickly than storage available elsewhere. Processor registers are at the top of the memory hierarchy and provide the fastest way for a CPU to access data. The number of these registers varies among different CPUs. Widely used CPU registers are shown in the table below. Register Type
Description
Instruction decoder
interprets the instruction to be executed.
PC (programmer counter)
holds the address of next instruction to be executed.
IR (instruction register)
holds the instruction being executed.
Process status register
holds the processor bit about operation performed by ALU.
ACC (accumulator)
stores intermediate and final results of calculation. It is the main working area of ALU.
General purpose register
stores any temporary information during execution of instruction.
MAR (Memory Address Register)
holds addresses of the data to be accessed.
MDR (Memory Data Register)
holds the data when they are transferred to and from the main memory.
32-Bit and 64-Bit Architectures The CPU architecture is migrating from 32 bits to 64 bits. Roughly speaking, a 32-bit CPU processes data in 32-bit chunks while a 64-bit CPU processes data in 64-bit chunks. A 32-bit CPU can address 232 memory addresses (about 4 GB of RAM) while 64-bit registers can address 264 addresses. Also, 32-bit CPUs must process 64-bit numbers in two steps, whereas 64-bit CPUs require only one step. To take full advantage of a 64-bit CPU, the mainboard, operating system, and application software should support 64-bit architecture. 64-bit processors provide full compatibility with 32-bit operating systems and application software. Single and Multi-Core Processors A multi-core processor combines two or more independent cores into a single package composed of a single IC (integrated circuit) packaged together. A dual-core processor contains two cores, and a quad-core processor contains four cores. 54
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Cores in a multi-core device may share a single coherent cache at the highest on-device cache level (e.g. L2 for the Intel Core 2) or may have separate caches (e.g., current AMD dual-core processors). A dual-core processor with two cores at 2 GHz may perform very nearly as quickly as a single core of 4 GHz if the software has been designed to take advantage of available dual-core processors. If the software has not been designed for a dual-core processor, there will not be any increased speed for this software, but the processor will multi-task better because it can run two programs at once, one on each core.
Multitasking is the ability to execute two or more programs simultaneously.
The most commercially significant multi-core processors are those used in personal computers (primarily from Intel and AMD) and game consoles (e.g., the eight-core Cell processor in the PS3 and the three-core Xenon processor in the Xbox 360).
Intel Xeon server CPU
Inside an Intel Core 2 Duo CPU Intel Core i7 quad-core desktop CPU
Intel Corporation Intel is the world’s largest semiconductor company and the inventor of the x86 series of microprocessors, the processors found in most personal computers. Intel was founded in 1968 as Integrated Electronics Corporation It is based in California, USA. Intel also makes motherboard chipsets, network cards and ICs, flash memory, graphic chips, and other devices related to communications and computing. The Core 2 brand includes a range of Intel’s consumer 64-bit x86-64 single, dual, and quad-core CPUs based on the Intel Core micro architecture. Intel Core 2 processors with vPro technology (designed for businesses) include the dual-core and quad-core branches. Some of Intel’s latest CPU products are Intel Core i7, Intel Centrino 2 vPro, Intel Core 2 vPro, Intel Atom, and Intel Xenon 7500.
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Intel Atom Mobile CPU
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Advanced Micro Devices (AMD) AMD is an American semiconductor company based in California. Its main products include microprocessors, motherboard chipsets, and graphic processors for servers, workstations, and personal computers, and processor technologies for handheld devices, digital television, automobiles, and game consoles. AMD is the second-largest global supplier of microprocessors based on the x86 architecture after Intel Corporation and the third-largest supplier of graphic processing units. AMD Opteron 64-bit quadcore server CPU
AMD Phenom 64-bit qudcore desktop CPU
Some of AMD’s latest CPU products are AMD Phenom, AMD Athlon, AMD Opteron, and AMD Turion.
AMD Turion 64-bit Mobile CPU
VIA Technologies VIA Technologies is a Taiwanese manufacturer of integrated circuits, mainly motherboard chipsets, CPUs, and memory. Via Nano desktop CPU
VIA produces mobile CPUs. Some of VIA Technologies’ latest CPU products are VIA Nano L, VIA Nano U, VIA C7, VIA Eden Embedded, and VIA CoreFusion.
Memory (RAM) RAM (Random Access Memory) is temporary memory that the computer uses to store applications and data that are in use, for example, the operating system, and a word processor or database program. RAM is called “random access” because any storage location can be accessed directly. When you create data such as a letter or a picture, the computer stores the data in RAM and then copies them to the hard disk when you save your work. Via C7 mobile CPU
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Memory Hierarchy Many computer systems have a memory hierarchy consisting of CPU registers, SRAM caches (level 1 caches), external caches (level 2 caches), DRAM, and virtual memory on a hard drive. This entire pool of memory may be referred to as “RAM” by many developers. The overall goal of using a memory hierarchy is to obtain the highest possible average access performance while minimizing the total cost of the entire memory system. Generally, the memory hierarchy follows the access time, with the fast CPU registers at the top and the slow hard drive at the bottom.
Microprocessor CPU
Fastest
Level 1 cache
Fast
Level 2 cache
Slow
Memory
Slowest
Virtual Memory
Multiple levels of memory
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The amount of RAM used in modern computers is expressed in megabytes (MB) and gigabytes (GB). Most new desktop and laptop computers should have a minimum of 2GB of RAM. The more memory a computer has, the faster the applications will run and the more stable the computer will be. When the amount of RAM is not enough for an application, a part of the hard disk is used as RAM. This part of the disk is called virtual memory.
Static RAM (SRAM) Static RAM is a type of RAM that holds its data without external refresh for as long as power is supplied to the circuit. SRAM can be contrasted to dynamic RAM (DRAM), which must be refreshed many times per second to hold its data contents. SRAMs are used for specific applications within the PC. SRAM is faster than DRAM but much more expensive and occupies more space than DRAM. Because cache memory needs to be very fast and not very large, SRAMs are used for level 1 cache and level 2 cache memory.
L2 cache modules
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Dynamic RAM (DRAM) Dynamic RAM is a type of RAM that only holds its data only if it is continuously accessed by special logic called a refresh circuit. Many hundreds of times each second, this circuitry reads the contents of each memory cell, whether the memory cell is being used at that time by the computer or not. Due to the way in which the cells are constructed, the reading action itself refreshes the contents of the memory. If it is not refreshed regularly, then the DRAM will lose its contents, even if it continues to have power supplied to it. This refreshing action is why the memory is called dynamic. All PCs use DRAM for their main system memory because they are much cheaper and take up much less space, typically 1/4 the silicon area of SRAMs or less. There are many different kinds of specific DRAM technologies and speeds available. These have evolved over many years of using DRAM for system memory. The main system memory types are SDRAM, DDR, and DRAM.
A SIMM or single in-line memory module is a type of memory module containing random access memory used in computers from the early 1980s to the late 1990s. A DIMM (dual in-line memory module) is a double SIMM. Like a SIMM, contains one or several random access memory (RAM) chips on a small circuit board with pins that connect it to the computer motherboard. Standard SIMMs have a 32-bit data path, whereas standard DIMMs have a 64-bit data path.
RAM slots with a DDR module
zzSDRAM (Synchronous DRAM): SDRAM is a 3.3 volt technology that uses 168-pin SDRAM DIMMs. SDRAM is able to scale to 133 MHz (PC133) officially and up to 180MHz or higher unofficially.
An SDRAM module
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Clock Speed is also called clock rate, the speed at which a microprocessor executes instructions. Clock speed is usually measured in MHz or GHz. The CPU requires a fixed number of clock ticks (clock cycles) to execute each instruction. The faster the clock, the more instructions the CPU can execute per second.
zzDDR (Double Data Rate SDRAM): DDR basically doubles the rate of data transfer of standard SDRAM by transferring data on the up and down tick of a clock cycle. DDR memory operating at 333 MHz actually operates at 166 MHz * 2 (PC333 / PC2700) or 133 MHz*2 (PC266 / PC2100). DDR is a 2.5 volt technology that uses 184 pins in its DIMMs. There are several types of double data rate (DDR) RAM. DDR has been around since 2000. The original is sometimes called DDR1. DDR2 was introduced in 2003. The primary improvement of DDR2 is the external data bus operating at twice the clock rate. It took a while for DDR2 to reach widespread use. DDR3 began appearing in mid-2007. DDR3 SDRAM is an improvement over its predecessor, DDR2 SDRAM. The primary benefit of DDR3 is the ability to transfer data at twice the data rate of DDR2.
A DDR module
zzRambus DRAM (RDRAM): RDRAM is a serial memory technology that arrived in three types, PC600, PC700, and PC800. PC800 RDRAM has twice the maximum throughput of old PC100 SDRAM, but a higher latency. RDRAM modules with multiple channels, such as those in Pentium 4 motherboards, are currently the best in memory throughput, especially when paired with PC1066 RDRAM memory.
An RDRAM module
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Memory Latency Latency refers to the delays that occur when a computer tries to access data in RAM. Such a delay occurs every time a CPU or another requestor reads or writes something in memory. It is the time that elapses between the moments a memory controller tells the memory module to access a particular location and the moment the data from the given location is available on the module’s output pins.
Task Manager shows you the programs, processes, and services that are currently running on your computer. You can use Task Manager to monitor your computer’s performance or to close a program that is not responding. You can open Task Manger by pressing CTRL+SHIFT+ESC.
Open the Windows Task Manager program and check the current memory usage of your system.
Windows Task Manager Performance tab
What causes each of the following two cases? zz Case 1: Your RAM is faster than your motherboard system bus. zz Case 2: Your RAM is slower than your motherboard system bus.
When you start your computer, it does a RAM test and counts the amount of RAM your system has. Start your computer and check how much RAM you have in your PC. Chapter 2 - Hardware
Visit a computer seller’s web site and read about the current different RAM specifications, including manufacturer, size, type, number of pins, speed of RAM, price, and so on. 61
Expansion Cards A device driver or software driver is a program that controls a particular type of device that is attached to your computer. It allows the operating system and related programs to interact with the hardware device. Many device drivers are built into the operating system.
An expansion card (also known as an add-on card, internal card, or interface adapter) is an electronic board added in a desktop computer to provide or expand features not offered by the motherboard. Expansion cards need device drivers to function properly.
Installing an expansion card
Some Types of Expansion Cards zzVideo cards zzSound cards zzNetwork cards zzTV tuner cards zzVideo processing cards zzModems zzHost adapters such as SCSI and RAID controllers zzInterface adapter cards, including parallel port cards, serial port cards, multi-I/O cards, USB port cards, and proprietary interface cards
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Video Card (Graphics Accelerator Card, Display Adapter, Graphics Card) A video card is used to transfer data to your monitor so that they can be displayed. Modern computers frequently process graphical functions. If you are playing video games and creating 3D graphics and animations, your video card is the most important component in your PC. Some video cards offer added functions, such as video capture, TV tuner adapter, MPEG-2 and MPEG-4 decoding, or even the ability to connect multiple monitors. A video card in a modern PC can connect to the mainboard in one of several different ways: zzOn-board: The graphics chips and memory are part of the mainboard. zzPCI/PCI Express: The graphics card plugs into the PCI bus. zzAGP: The graphics card plugs into a special slot designed especially for graphics devices.
An AGP video card with 256 MB DDR2 RAM
A PCI Express 64-bit video card with 256 MB hypermemory
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A video card consists of a printed circuit board on which the following components are mounted: Graphics rendering is the process of generating an image from a model by means of computer programs. It is the final process of creating the actual 2D or 3D image or animation from the prepared scene. 3D rendering is the process of producing an image based on three-dimensional data (viewpoint, geometry, lighting, and texture) stored within a computer.
A pipeline is a sequence of one or more commands separated by the pipeline control operator. The standard output of all but the last command is connected to the standard input of the next command.
zzGraphics Processing Unit (GPU): A GPU is a dedicated graphics microprocessor optimized for floating point calculations, which are fundamental to 3D graphics rendering. The main attributes of the GPU are the core clock rate, which typically ranges from 250 MHz to 850 MHz, and the number of pipelines, which translate a 3D image characterized by vertices and lines into a 2D image formed by pixels. zzVideo BIOS: The video BIOS or firmware contains the basic program that governs the video card’s operations and provides the instructions that allow the computer and software to interface with the card. It may contain information on the memory timing, operating speeds, and voltages of the graphics processor and RAM and other information. zzVideo RAM: On-board video cards (integrated into the motherboard) usually use the computer RAM (lower throughput). If it is not integrated, the video card will have its own video memory, called Video RAM. The memory capacity of most modern video cards ranges from 128 MB to 2.0 GB. Because video memory needs to be accessed by the GPU and the display circuitry, it often uses special high speed or multi-port memory. The memory clock rate in modern cards is generally between 400 MHz and 2.4 GHz. Most graphics cards have two monitor connections: VGA and DVI. In addition to VGA and DVI, some graphics cards may have output connectors for S-video, ViVo, and FireWire. zzVGA (CRT) Output: VGA (video graphics array) is an analog-based standard adopted in the late 1980s designed for CRT displays. zzDVI Output: DVI (Digital Visual Interface) is a video interface standard designed to maximize the visual quality of digital display devices, such as flat panel LCD computer displays and digital projectors.
Firmware is permanent instructions and data programmed directly into the circuitry of read-only memory for controlling the operation of the electronic devices.
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zzS-Video (TV) Output: Separate video, a technology for transmitting video signals over a cable by dividing the video information into two separate signals: one for color and one for brightness. zzViVo Output: Video in/video out enables video cards to have bidirectional (input and output) video transfer. Usually, this output is used for analog video cameras. zzFireWire (IEEE-1394) Output: FireWire is a serial bus interface standard for high-speed communications and real-time data transfer, frequently used for digital audio and digital video. Most digital video cameras have an IEEE-1394 plug.
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1
1 S-Video output 2
2 VGA output 3 DVI output
3
A video card with S-Video, VGA, and DVI outputs
A video card with ViVo and Dual-DVI outputs
As the processing power of video cards has increased, so has their demand for electrical power. Power demands of GPUs have continued to rise, so the video card may be the biggest power consumer in a computer. Nowadays, video cards with high power consumption (75 or 150 Watt) connect directly to the power supply to supplement power. Cooling devices (heat sink, fan, water block) are incorporated to protect the video cards from overheating.
OpenGL was developed by Silicon Graphics in the early 1990s. It is free, open, multilanguage, and multi-platform. It is widely used in CAD, virtual reality, scientific visualization, information visualization, flight simulation, and some games.
Application Programming Interface (API) is a set of routines, protocols, data structures, and tools provided by libraries for building software applications
A video card cooling device
OpenGL and DirectX are APIs (Application Programming Interfaces) for high performance graphics. They handle tasks related to multimedia, game programming, CAD, virtual reality, simulations, and so on. OpenGL and DirectX supported video cards give the advantages of using those graphics libraries. Chapter 2 - Hardware
Microsoft DirectX is a collection of application programming interfaces (APIs) for handling tasks related to multimedia, especially game programming and video, on Microsoft platforms (Windows Vista, Windows 7, etc.). 65
Find out the specifications of your video card and complete the table below. Card Name Slot Type Amount of Memory Graphics Processor Supported Monitor Resolution Driver Version Output Connectors
Monaural (mono) sound reproduction is single-channel. All the loudspeakers are fed from a common signal channel. Mono sound has been replaced by stereo sound in most entertainment applications. Stereophonic (stereo) sound is the reproduction of sound using two or more independent audio channels. Stereo systems create a pleasant and natural impression of sound heard from various directions, as in natural hearing.
Sound Card (Audio Card) A sound card facilitates the input and output of audio signals to and from a computer under control of computer programs. Typical uses of sound cards include providing the audio component for multimedia applications such as composing music, editing and displaying video or audio. Most computers are equipped with sound cards, usually part of the motherboard, with a stereo speaker output and a microphone input. Two important characteristics of sound cards are polyphony and sound channels. Polyphony is more than one distinct voice or sound playable simultaneously and independently, and the number of simultaneous channels.
An 8-channel sound card
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The channels are intended as the number of distinct electrical audio outputs, which may correspond to a speaker configuration such as 2.0 (stereo), 2.1 (stereo and sub woofer), and so on. Stereo sound was introduced in computers the early 1990s, and quadraphonic sound (four channels in which speakers are positioned at the four corners of the listening space) came in the late 1990s. Quadraphonic was shortly followed by 5.1 channel audio. The latest sound cards support up to 8 physical audio channels in the 7.1 speaker setup. Depending on the functions, the sound cards may have differing numbers of connectors. The connectors on the sound cards are color coded. They also have symbols depicting arrows, holes and sound waves that are associated with each jack position. The meaning of each color is given in the chart: Sound Card Connector Color Codes and Symbols Color
Connector
Lime Green
Line-out, front speakers, headphones
Pink
Analog microphone audio input.
Light Blue
Stereo line in (for signal from a cassette tape recorder or similar sound source)
Orange
Subwoofer (to reproduce very low bass frequencies) and center out
Black
Rear surround speakers for 5.1 and 7.1 systems
Gray
Middle Surround Speakers for 7.1 systems
Gold
Midi / Game port (joystick)
Network Interface Card (NIC) A network interface card (Ethernet card, network adapter) allows computers to communicate over a computer network through cables (or via radio waves). Network interface cards are often used in offices to connect computers in the same room or building. To communicate over longer distances, a modem is usually used. Most new computer systems have a network interface built into the motherboard. Traditional Ethernet supports data transfers at the rate of 10 Megabits per second (Mbps). Modern Ethernet adapters all support the 100 Mbps Fast Ethernet standard and Gigabit Ethernet support at 1 Gbps (1000 Mbps).
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A network is a group of computers connected together in a way that allows information to be exchanged among the computers. Ethernet is the most widelyinstalled local area network (LAN) technology. Ethernet was originally developed by Xerox from an earlier specification called Alohanet and then developed further by Xerox, DEC, and Intel. Token Ring and FDDI (fiber optic) are two other widely-used LAN technologies.
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54 Mbps wireless PCI adapter
Both Bluetooth and infrared technologies are used to established temporary wireless communication. While Bluetooth is very applicable for networking, infrared is more appropriate for the direct connections. Bluetooth is a wireless technology providing wireless personal area networks (WPANs) for small devices. It is shortrange (10 meters) technology designed to connect technology devices, like computers, keyboards and mice, mobile phones and headsets, printers, digital cameras, PDAs, and other mobile devices. Bluetooth devices generally communicate at less than 1 Mbps. Infrared technology allows computing devices to communicate via very shortrange (a few meters) wireless signals. Infrared networks were designed to support direct twocomputer connections only. Infrared technology operates with 115 Kbps, 1.15 Mbps, or 4 Mbps. 68
10/100/1000 PCI network card
Wireless communication is the transfer of information over a distance without the use of electrical conductors or “wires.” In wireless networking, (2.4 GHz Wi-Fi (wireless fidelity) devices are used to meet a variety of needs. Perhaps the most common use is to connect laptop users who travel from location to location. Another common use is for mobile networks that connect via satellite. A wireless transmission method WLAN (wireless local area networks) is a logical choice for networking a LAN (local area network) segment that must frequently change locations. WLANs operate at different speeds, depending on which Wi-Fi standard they support. 802.11b WLANs offer a maximum theoretical bandwidth of 11 Mbps. 802.11a and 802.11g WLANs offer a theoretical bandwidth up to 54 Mbps.
Local area network (LAN)
Wireless local area network (LAN)
ICT - Information and Communication Technology
Modem (Modulator/Demodulator) A modem (from modulator-demodulator) is a device that allows your computer to communicate with other computers over an ordinary phone line. When it receives analog data through a connection, it has to convert them to digital data to be usable by the computer. Likewise, it reverses the action when it has to send data. Modems can be internal or external. An internal modem plugs directly into a slot on the mainboard. An external modem plugs into one of the computer ports at the back of the system unit. Internal modems are cheaper and take up less space. External modems are easier to troubleshoot and reset.
56K internal data/fax/voice PCI modem
The type of modem used depends on depends on the Internet connection technology dial-up, ISDN, ADSL, cable, mobile, and so on. Modem speeds are measured in bps, bits per second. A cable modem can be used to achieve extremely fast access to the Internet, including the web. Type
Speed Rate
Dial-Up
56 Kbps
ISDN
64 Kbps
ADSL
1.5 Mbps to 9 Mbps
ADSL 2+
24 Mbps
Dial-up, ISDN (integrated services digital network), and ADSL (asymmetric digital subscriber line) modems use telephone lines to transfer data, whereas cable modems use dedicated cable television lines. Mobile (cellular) modems use mobile phone lines (wireless) and connect to the Internet wherever a mobile phone can establish a connection to a GSM operator. Dial-up technology is used to establish a temporary Internet connection.
An external ADSL modem/router
The connection between your computer and ISP’s (internet service provider) computer
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Find out the Internet connection possibilities and installation cost and monthly fee for each type of connection in your region. You can visit local Internet service providers (ISP) to gather adequate information.
Number the statements in the correct order from 1 to 7 to describe how to send an e-mail. When your message reaches your friend’s computer, the analog signals are changed back to the digital signals that are now displayed on your friend’s computer. Type a message to your friend who also has a computer with a modem. This whole process is reversed as your friend types a message to you from his computer to yours. 1
Attach a modem to your computer. Your modem changes your message into analog signals that can travel through telephone lines to your friend’s house. Connect your computer to a telephone line. Your friend enjoys reading your message.
TV Card TV cards usually have two functions, TV decoding and TV tuning. The TV decoder transfers the picture that is on the computer screen to a TV. Doing so is useful for business presentations. The TV tuner allows you to watch TV channels on the monitor so that your monitor becomes like a TV. Most TV tuners also function as video capture cards, allowing them to record television programs onto a hard disk. A PCI TV card and its remote control
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PC Card and ExpressCard Both PC cards and expresscards are small, credit-card-sized boards that extend a computer’s capability, for example, by providing more memory or working like a modem. They are particularly useful for laptops and other personal computers that do not have room for full-sized expansion cards. They connect to the outside of a computer through a special socket, called a PCMCIA (Personal Computer Memory Card International Association) slot. PC cards were originally designed for computer memory expansion, but the existence of a usable general standard for notebook peripherals led to many kinds of devices (for memory, communications, multimedia and security) being made available in this form.
Expresscard TV tuner
SCSI Card SCSI (small computer system interface) is a type of interface used for components, such as hard drives, optical drives, scanners, and tape drives. It is a competing technology to standard IDE and SATA. While the less expensive IDE and SATA technologies are built into motherboards, SCSI is a technology that must be added by purchasing a SCSI controller. The SCSI card fits into an internal slot. SCSI devices are then connected to this card. SATA drivers have largely replaced SCSI in new systems, but SCSI is still in use. SCSI is a fast and robust technology and has traditionally been used in servers. In addition to speed, another great advantage SCSI has over IDE and SATA is that many devices can be attached to a single SCSI port.
PCI-X SCSI card
Open up your system unit and list the expansion cards in your system. Do not forget to unplug your PC before opening the case and be careful not to damage your PC. Expansion Card Type
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Specifications
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Indicate whether each statement below is true or false. Statement
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True
1
All the cards in a computer are connected to the motherboard.
2
The CPU is like a computer’s brain.
3
There are several motherboards in a computer.
4
Motherboard, mainboard, and system board refer to the same device.
5
The CPU is situated on the mainboard.
6
The video card sends information to the monitor.
7
All modems are internal devices.
8
The power supply converts alternating current (AC) signal coming from your wall outlet into a usable direct current (DC) signal.
9
IDE, ATA, SATA, and SCSI are interfaces for components such as hard drives and optical drives.
10
PCI is a common slot for many types of expansion cards.
11
AGP is a common slot for many types of expansion cards.
12
You can use an expansion slot for many cards at the same time.
13
Modems are needed to communicate over greater distances.
14
A network card consumes more power than any other expansion card.
15
Wi-Fi, Bluetooth, and infrared are wireless technologies.
False
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Follow the instructions to see what you have in your system unit. You will need a Phillips (cross) screwdriver. 1. Switch off your computer and unplug the power cable from the computer. 2. Open the chassis. 3. Take out the IDE cable between the CD-ROM drive and the mainboard. 4. Unplug the power cable from the CD-ROM drive. 5. Take out the CD-ROM drive. 6. Repeat steps 3,4, and 5 for the hard disk. 7. Take out the other boards in the system unit. 8. Remove the RAM modules from the mainboard. 9. Remove the CPU from the mainboard. 10. Find the power supply. 11. Find the ROM-BIOS chip. 12. Find the battery. 13. Find the expansion slots. 14. Find the chipset (bus arbitrator). 15. Find the buses. 16. Find the internal speaker. 17. Find the parallel, serial, PS/2, and USB ports. 18. Reassemble your computer. 19. Check that your computer works properly.
Input Devices Input devices are peripheral devices that enter data and instructions into the computer. A mouse and a keyboard are the most used input devices. Other common input devices are scanners, microphones, graphics tablets, digital cameras, touch screens, and joysticks.
Keyboard The keyboard is the most common way to enter information into a computer. Today, standard keyboards have 104 or 105 keys. An electronic circuit inside the keyboard transmits the code of a pressed key to the CPU. Chapter 2 - Hardware
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Most of the keys on a keyboard are used to enter numbers, letters, and punctuation marks. There are also function keys (used for special functions in applications), keys for working with text and documents (for example, the Page Up and Page Down keys), and other keys used to make special key combinations (Alt and Ctrl). There are a number of different arrangements of alphabetic, numeric, and punctuation symbols on keys. These different keyboard layouts exist mainly because different people input text in different languages. QWERTY is the most used modern-day keyboard layout on English-language computers. It takes its name from the first six letters at the upper left of the keyboard. Many modern keyboards have extra keys for accessing music, web, and other frequently used programs and features, such as a mute button, volume buttons, or a standby (sleep) button.
QWERTY English keyboard
A virtual keyboard
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The bluetooth multimedia keyboard and mouse
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How many keys does your keyboard have? Count them.
Function Keys: The function keys on a keyboard are labeled from F1 to F12. They are usually located at the top of the keyboard. Function keys are used in application programs or by the operating system as a faster way to access certain features of the software. For example, pressing F1 when an application is running often displays a help screen.
The virtual keyboard (Projection Keyboard) technologies allow users to input characters into a device without any physical keyboard. Such keyboards watch finger movements and translate them into keystrokes in the device. They are usually integrated into mobile devices such as PDAs and smart phones.
Enter Key: The Enter key (also called the Return key) is used to signal the end of an entered command or line of text, so that the computer can begin processing. In word processing programs, pressing the Enter key starts a new paragraph.
Ctrl Key: The Ctrl (control) key is used with other keys to access special software functions faster. For example, in some word processing applications, pressing Ctrl+C (Ctrl with the C key) copies the selected text.
Spacebar: The spacebar is the longest key on the bottom row of most keyboards. It sends a space character to the computer.
Arrow Keys: Most keyboards have four keys that are labeled with arrows pointing up, down, left, and right. Pressing an arrow key usually moves the cursor or, in some programs, extends a section of selected text.
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Page Up and Page Down Keys: The Page Up key is a standard key (often labeled ‘PgUp’) on most keyboards. Its function changes in different programs. In word processing programs, pressing the Page Up key moves the cursor up to the top of the previous page, or up a specific number of lines. The Page Down key is a standard key (often labeled ‘PgDn’) on most computer keyboards like the Page Up key. Home and End Keys: The Home key controls the position of the cursor. The Home key moves the cursor to a certain position, usually the start of a line, the start of a screen, or the start of a file, depending on the program. The End key controls the position of the cursor in the opposite manner the Home key. Caps Lock Key: The Caps Lock key changes the letter between capital letters (A, B, C, etc.) and lower case letters (a, b, c, etc.). The Caps Lock key does not change the input of numbers, punctuation marks, or other symbols. Shift Key: The Shift key gives the other keys an alternative function. When combined with alphabetic keys, the Shift key causes the system to output a single capital (or lower case) letter. For example, pressing Shift with the A key makes a capital ‘A’ instead of a lower case ‘a’. The Shift key can also be combined with other keys to produce program -dependent results. There are typically two shift keys, on the left and right sides of the keyboard. Backspace Key: Pressing the Backspace key moves the cursor to the left, one character at a time, usually erasing each character on the screen as it moves. To move the cursor or insertion point backward without deleting characters, use the arrow keys. The Backspace key takes you to the previously visited page in many web browser (Internet Explorer, Firefox etc.). Escape Key: In many applications, pressing the Escape key (labeled ESC or Esc) usually cancels or aborts the current operation and moves you back to a previous menu or exits the application. It is usually located at the upper left corner of the keyboard. 76
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Insert: The Insert key (labeled Insert or Ins) can perform different functions in different applications. In word processing applications, pressing the Insert key toggles between the overwrite mode (in which typed characters delete the existing text) and insert mode (in which all the characters you type are inserted at the cursor position). Pause Key: Pressing the Pause key temporarily stops the operation of a program or a command. The Pause key is used, for example, to stop text moving up the screen so that you can read a multi-screen listing or document. Print Screen Key: The only function of this key is to take a snapshot or picture of your computer screen and copy it to the Clipboard. Once you have the image on the Clipboard, you can paste it in any graphics editing program. Alt + Print Screen takes a screenshot of the currently selected window, not the entire screen like the normal screenshot function. The standard position of Print Screen key is the upper right corner of your keyboard.
The clipboard is a section of RAM where your computer stores copied data. The data can be a selection of text, an image, a file, or other type of data. It is placed in the clipboard whenever you use the “Copy” command (Ctrl+C). Data from the clipboard can be pasted into a document or program using the “Paste” command (Ctrl+V).
Tab Key: The Tab (Tabulator) key is most commonly used in word processing programs to insert tab characters (long spaces) into a document; that is it, moves the insertion point (cursor) to the next tab stop. Many database and spreadsheet programs allow you to press the Tab key to move around within a record or between table cells. Num Lock Key: This key switches the numeric keypad from numeric mode to cursor control mode and vice versa. In numeric mode, you can use the keypad like a calculator, entering numbers and making calculations. Numeric Keypad: The numeric keypad is a set of number and symbol keys, usually on the right side of a keyboard. Numeric keypads make it easier to enter large amounts of numeric data. When the Numeric Lock (Num Lock) is on, the numeric keypad keys produce numbers on the screen. When the Numeric Lock is off, the numeric keypad keys move the cursor and the focus around the screen.
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Scroll Lock Key: This key (often with an associated status light) is on most modern keyboards. The behavior of the key depends on the particular software in use. Many applications ignore the Scroll Lock setting. In the original design, scroll lock was intended to modify the behavior of the arrow keys. When the scroll lock mode was on, the arrow keys would scroll the contents of a text window instead of moving the cursor.
Draw a QWERTY English layout keyboard on a piece of paper. Take an article from an English source. Count the number of times each letter occurs and write the numbers on the corresponding keyboard keys in your picture. Do you think the keyboard is well designed?
Touch Screen Touch Screen is a type of display screen that has a touch-sensitive transparent panel covering the screen so that it can recognize the location of a touch on its surface. Instead of using a pointing device such as a mouse or light pen, you can touch the screen with your finger or a stylus to point directly to objects on the screen.
Using a touch screen with finger
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Using a touch screen with stylus
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Although touch screens provide a natural interface for computer novices, some users find it difficult to point accurately to small areas of the screen, and it may tire to the arms after long use. Touch screens are especially useful for portable hand devices (PDAs, portable media players, and mobile phones), public information displays, and information kiosk systems.
Light Pen A light pen is a form of a light-sensitive wand used in conjunction with a computer’s monitor. It allows the user to point to displayed objects or draw on the screen in a similar way to a touch screen but with greater positional accuracy. The user brings the pen to the desired point on the screen and presses the pen button to make contact.
Reading news on a tablet PC.
Light pens work in two different ways: The monitor contains a light sensitive detector that picks up light emitted from the pen and calculates its position on the screen, or contrary to what it looks like, some pens do not shine light onto the screen; rather, the screen beams into the pen. Screen pixels are constantly being refreshed. When the user presses the button, the pen senses light, and the pixel being illuminated at that instant identifies the screen location.
Graphics Tablet (Pen Tablet)
Using a light pen
A tablet is an alternate type of input device that can be used in place of a pointing device. It enables you to enter drawings and sketches into a computer. The tablet consists of two parts, a flat surface for drawing and a pen or stylus that is programmed to work with the tablet. The graphics tablet is most suited for artists and those who want the natural feel of a pen-like object to manipulate the cursor on their screen. For digitizing tablets, each point on the tablet represents a point on the display screen in a fixed manner. Tablets differ from mice, for which all movement is relative to the current cursor position. The static nature of digitizing tablets makes them particularly effective for tracing drawings. Most modern digitizing tablets also support a mouse emulation mode in which the pen acts like a mouse.
A Graphics tablet and its stylus
Concept Tablet and Concept Keyboard The concept tablet is a touch sensitive tablet similar to the graphics tablet that has various pictures and symbols on the surface. A concept keyboard is a flat board that contains a grid of buttons with pictures and symbols. Tapping a picture or symbol causes a command to be input into the computer. Appropriate software running on the computer makes sense of that specific command. Concept tablets and keyboards are widely used for special purpose computers when fast input is needed. They are ideally suited for selecting from a limited range of choices, such as taking orders in a fast food restaurant. Chapter 2 - Hardware
A concept keyboard
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Webcam Motion detection simply compares two successive incoming images from a webcam or IPcam and counts the number of different pixels to determine whether a change has occurred in the target view.
A webcam is essentially a small camera that is connected to a computer, either directly or wirelessly, and gathers a series of images that are viewed in real time on the computer screen or over a network, especially over the Internet. Because it allows for cheap real-time communication from anywhere in the world, webcam technology is widely used by all sorts of people for all sorts of different reasons. Friends and relatives use webcams for video chat, and businesses use webcams for online video conferencing; in security and gaming, webcams are used for motion detection.
Some types of webcams
Install a webcam on your computer and play one of the motion games (www.ovogames.com).
ORC (optical character recognition) is a technology that takes data from a paper document and converts them into editable digital text data. The document is first scanned; then OCR software searches the document for letters, numbers, and other characters.
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Scanner A scanner uses special light sensors to capture (or photograph) an image printed on paper and translate the information into a form the computer can use. You can then use special text or graphics software to work with the scanned image. Such software uses the TWAIN program to read in the image. To edit text read by an optical scanner, you need an optical character recognition (OCR) system to translate the image into ASCII characters. Most optical scanners sold today come with OCR packages. Very high resolution scanners are used for scanning for high-resolution printing, but lower resolution scanners are adequate for capturing images for computer display. ICT - Information and Communication Technology
Type
Features
Flatbed scanners
Like a photocopy machine, a flatbed scanner moves the light sensors over the image.
Photo scanners
Photo scanners are used especially to digitize film negatives or slides.
Sheetfed scanners
Sheetfed scanners are usually smaller than flatbed scanners; A document or photo is fed into the scanner rather than placed on top.
Portable (handheld) Like barcode scanners, portable scanners are used to scanners move the sensors over the image. Drum scanners
A flatbed scanner
A drum scanner is a specialized scanner commonly used by the printing industry for very high quality scans; it uses a high-speed rotating glass drum to scan images
A handheld scanner
A sheetfed scanner
TWAIN (technology without an interesting name) is a widely used program that lets you scan an image (using a scanner) directly into the application (such as PhotoShop) where you want to work with the image. Without TWAIN, you would have to close an application that was open, open a special application to receive the image, and then move the image to the application where you wanted to work with it.
A drum scanner
Write a paragraph of text your handwriting. Then scan it as text with an OCR scanner. How well does the scanner recognizes your handwriting? Using only capital letters in your handwriting may improve the success of this task.
PC Microphone A microphone converts sound waves into electrical signals that can be understood by your computer’s sound card. The sound card converts the electrical signals into digital data that your computer can process. You can use a microphone for performing various tasks. For example, you can hold a conference with your business partners over the Internet, you can chat with your friends online, or you can record and store speech or music on your computer. Chapter 2 - Hardware
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There are many different styles and brands to choose from. You can find desktop microphones that are free standing, headset style microphones, or in-ear microphones that sit behind the ears and head.
Different types of computer microphones
Do you know that other people hear your voice different from the way you do? When you speak, you are the source of the sound. A lot of people seem to be surprised to hear their own voices from an external source. Record your sound to your PC and listen to it. Is it different from what you expected?
Joystick A joystick is a pointing device consisting of a stick-like object attached to a base that can be pushed in four or more directions. It controls the movement of a pointer or some other display symbols. A joystick is similar to a mouse, except that, with a mouse, the cursor stops moving as soon as you stop moving the mouse. With a joystick, the pointer continues moving in the direction the joystick is pointing. To stop the pointer, you must return the joystick to its upright position. Most joysticks include one or more push-buttons. Joysticks are largely used in computer games and for CAD/CAM systems.
A Joystick
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Match each task with the most appropriate device. Task
Devices
Playing a flight simulation game.
1
Typing an article.
2
Mouse
Having a visual chat with your friend.
3
Touch screen
Converting a printed document to a digital document.
4
Graphics tablet
Making an online conversation.
5
Concept tablet
Using handwriting to enter text into your PC.
6
Webcam
Surfing on the Internet with a MIB (mobile internet device).
7
Scanner
Gathering costumers’ orders in a fast food restaurant.
8
Microphone
Formatting plain text in word processing software.
9
Joystick
2
Keyboard
Mouse A mouse is the most common input device along with the keyboard. It is used to point to things and select things on the screen. It functions by detecting two-dimensional motion relative to its supporting surface. zzYou use your mouse whenever you want to move your cursor or activate something. Your mouse senses your motion and your clicks and sends them to the computer so it can respond appropriately. The mouse’s motion typically translates into the motion of a pointer on a display, which allows for fine control of a GUI (Graphical User Interface). The name mouse originated at the Stanford Research Institute and derives from the resemblance of computer mice to natural mice.
A mechanical mouse with Its tracking ball
There are three basic types of mice: zzMechanical Mouse: This type has a rubber or metal ball on its underside that can roll in all directions. Mechanical sensors within the mouse detect the direction the ball is rolling and move the screen pointer accordingly. zzOptomechanical Mouse: This type is the same as a mechanical mouse, but it uses optical sensors to detect motion of the ball. zzOptical Mouse: This type uses a laser to detect the mouse’s movement. Optical mice have no mechanical moving parts. They respond more quickly and precisely than mechanical and optomechanical mice. Chapter 2 - Hardware
An optical mouse
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Five basic actions can be performed with your mouse: zzClick: Press and release the left mouse button, without moving the mouse. zzRight-Click: Press and release the right mouse button, without moving the mouse. zzDouble-Click: Press and release the left mouse button twice in rapid succession without moving the mouse. zzDrag and Drop: Press and do not release the left mouse button, then move the mouse with the button still held down, and finally release the button. zzScroll: Many mice have a scroll wheel between the left and right buttons.
Touchpad and trackpoint are two alternative pointing devices for mice that are usually found on laptop computers.
Wireless optical mouse
Touchpad
Trackpoint
Turn on your computer. Open the Windows Calculator program and calculate approximately how many days you have lived until today. How many times did you click your mouse to complete this operation? 84
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Output Devices Output devices are peripheral devices that output information that has been held or generated within a computer. Because most information from a computer is output in either a visual or auditory format, the most common output devices are the monitor and speakers. These two devices provide instant feedback to the user’s input, such as displaying characters as they are typed or playing a song selected from a playlist. Beside the monitor and speakers, some other output devices are headphones, printers, plotters, and projectors.
Monitor A monitor or computer screen is a very common type of output device. A monitor displays images that have been generated by the computer’s video card. The monitor is attached to the video card by a cable. There are two main types of monitor: flat panel monitors and cathode ray tube (CRT) monitors. A flat panel monitor uses a liquid crystal display (LCD) instead of a cathode ray tube to display data. LCD monitors occupy less space, consume less energy, and are much lighter than CRT monitors. Many monitor companies have already stopped producing CRT monitors. A monitor connects to either a VGA (video graphics array) or DVI (digital visual interface) port on a video card. Both devices should support the same type of connection.
VGA and DVI Connectors
A CRT monitor
An LCD monitor
The display resolution refers to the number of distinct pixels in each dimension that can be displayed. The display is indicated by a number combination, such as 800 x 600. These numbers indicate that there are 800 dots horizontally across the monitor and 600 lines of dots vertically, equaling 480,000 dots that make up the image you see on the screen. Screen resolution affects the clarity of the text and images on your screen. At higher resolutions, items appear sharper. They also appear smaller, so more items fit on the screen. Chapter 2 - Hardware
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Refresh rate is the number of times per second a monitor redraws its screen image. A 60 hertz (Hz) vertical refresh rate indicates the on-screen image is redrawn 60 times per second. The higher the refresh rate, the sharper the on-screen image. Recently, besides the standard monitors (4:3 ratio), widescreen monitors (16:10 or 16:9 ratio) have taken a significant part of the market. Widescreen monitors are useful to watch movies, view two documents side by side, and see the main panel and the tool panels at the same time while working with graphics or photo editing programs such as Adobe PhotoShop. Besides such advantages, the main drawback of widescreen monitors is that they lack the vertical pixels to display web pages or the whole page of a document and so on. In lower resolutions (i.e., 1366x768). The surface area of a standard screen monitor is always bigger than the widescreen monitor of the same size.
16X9 widescreen and 4X3 square monitors
You may use multiple monitors if your graphics card has the ability to run them. Multiple monitors provide a high resolution working area at half price of a single widescreen monitor. When a second monitor is attached to your system, you can display the computer desktop across both monitors (spanning) or duplicate what is seen on the first monitor to the second one (cloning). Spanning is used mostly by designers and visual programmers, whereas cloning is used especially by people who are giving presentations to the audience. The physical space between two screens is a disadvantage with multiple monitors. That empty space is a distraction for many users. Another drawback to multiple monitors is that some DVD movies and games may not run properly on the second monitor.
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Multiple monitors with spanning mode
Multiple monitors with cloning mode
Printer A printer is an output device that prints text and computer-generated images onto paper or onto another physical medium, such as a transparent film. Printers can print in monochrome or color mode. There are many types of printers on the market to meet users’ demands. Depending on the printing technologies, printers are divided into three main categories: impact, ink-jet, and laser printers.
The world’s first computer printer was a 19th century mechanically driven apparatus invented by Charles Babbage for his Difference Engine.
Ink-jets (bubble-jets) printers: Ink-jet printers use tiny jets to spray ink onto the paper. An ink-jet printer places extremely small droplets of ink onto paper to create an image. Ink-jet printers are capable of producing high quality print that almost matches the quality of a laser printer. They are ideal for people who want to print small numbers of high quality copies, where speed is not important, for example, in a home or small office. An Ink-Jet Printer
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Laser Printers Laser printers produce high print quality at high speed. They are called laser printers because they use a laser beam to produce an image on a drum. The light of the laser alters the electrical charge on the drum wherever it hits. The drum is then rolled through a reservoir of toner, which is picked up by the charged portions of the drum. Finally, the toner is transferred to the paper through a combination of heat and pressure. This is also the way copy machines work.
1
1 Paper exit
A laser printer 6 2
2 Toner hopper 3 Fuser 4 Paper tray
3
5 Photoreceptor
orum assembly
6 Laser unit 4
5
Inside a laser printer
A dot-matrix printer
Ethernet is the most widely installed local area network technology. It provides highspeed bandwidth connectivity over local area networks.
Impact (dot-matrix) Printers Dot matrix printers push a row of pins through an ink ribbon onto the paper. The print quality increases with the number of pins. Most modern dot matrix printers have 24 pins. Dot matrix printers are used for cheaper, low quality printing, for example, printing stock information in a factory. Many printers are primarily used as local peripherals and are attached by a printer cable or a USB cable to a computer that serves as a document source. Some printers, commonly known as network printers, can serve as a device for any user on the network. Network printers have built-in network interfaces, typically Ethernet or wireless. A local printer can be shared with other computers in a network environment.
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Connecting a local printer to a computer
Connecting a network printer to a network
Plotter A plotter is an output device similar to a printer, but for larger images. Plotters use either pens or electrostatic charges and special chemicals to print an image. Plotters are restricted to line art (vector graphics), rather than raster graphics as with other printers. Pen plotters draw on paper or transparent film with one or more colored pens. Electrostatic plotters draw a pattern of electrostatically charged dots on the paper and then apply chemicals to keep the pattern in place. Plotters are used primarily in technical drawing and CAD applications. They have the advantage of working on very large paper sizes while maintaining high resolution. Another use has been found by replacing the pen with a cutter, and in this form, plotters can be found in many garment and sign shops to cut the patterns.
Vector graphics are graphics described by a set of mathematical instructions instead of being a series of discrete bits. They are typically line art illustrations. Graphics programs such as Adobe Illustrator and Corel Draw create vector-based graphics.
Raster graphics are digital images captured photographically. A common term for a raster image is a bitmap because the image is actually bits mapped to a display grid. MS Paint creates bitmap graphics.
A CAD drawing plotter
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Speakers and Headphones Speaker A speaker is an output device that plays sound generated by the computer’s sound card. The speaker is attached to the sound card by a cable. Most computers also have an internal speaker that is attached to the mainboard and that can play simple sounds.
A pair of stereo speakers with USB power connection
There are many different types of speakers: Floor-standing (in-room), bookshelf, in-wall, in-ceiling, and subwoofer. There are no certain criteria for selecting a speaker for your system. You should choose a speaker based on its sound quality, and the sound quality is a personal preference. Speakers usually need an electrical power outlet to operate. Less powerful speakers may be powered from a USB port. Headphone A headphone is a pair of speakers worn over or in the ears so only the wearer can hear the sound. Headphones are useful for cancelling the noise in the environment or listening to music or watching movies with mobile devices and avoiding disturbing other people nearby, especially in public places. Wireless headphones allow users to play games and to listen music without any cables. A headphone with an integrated microphone is usually called a headset.
A headset
Put a check () to show whether each device is an input device or an output device. Device Keyboard
Input
Output
Monitor Printer Mouse Scanner Joystick Microphone Speaker Floppy disk Plotter Touch screen Modem
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Data Storage Devices
Storage devices store digital data
Network appliance storage server
A storage device is a hardware device designed to store and retrieve information. There are two types of storage devices: temporary storage devices and permanent storage devices. RAM, CPU caches, and CPU registers are temporary storage devices. Those storages are used by the CPU, operating system, or other software. They are called temporary because information is lost after the power is switched off. Because temporary storage devices are connected directly to the computer’s CPU, they are considered primary computer storage devices or internal storage devices. Permanent storage devices hold information until it is deleted or overwritten. They do not lose data even when they are turned off. Hence, they are ideal back-up and data storage devices. Because they are not directly attached to the computer’s CPU, they are called secondary storage devices or external storage devices. It takes a longer time for the CPU to access secondary storage devices than primary storage devices. The term data storage device usually refers to a secondary computer device. Depending on the technology, secondary storage devices can be divided into three categories: magnetic, optical, and flash storage. The building blocks of digital images are bits, which can either be 0 or 1. Magnetic storage devices such as hard disks distinguish a one from a zero by changing the magnetic properties of the disk in that location. In an optical medium, data are recorded by making marks in a pattern that can be read back with the aid of a tiny beam of laser light precisely focused on a spinning polymer disc.
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Classification of storage devices
Hard Disk Drive A hard disk drive (HDD), commonly referred to as a hard drive, hard disk, or fixed disk drive, is a device that stores digitally encoded data on rapidly rotating platters with magnetic surfaces. Hard disks are the main large data storage area inside your computer. Hard disks are used to store your programs and data. They are much faster than most other types of storage device and can also hold much more data. A hard disk is made up of platters. Platters are rigid disks made of metal or plastic. A platter is divided into sides (top and bottom), tracks (rings on each surface), and sectors (sections of each ring). Sectors are the smallest physical storage units on a disk. Usually, each sector holds 512 bytes of data. A set of two to eight sectors grouped together is called a cluster.
A 3,5-inch hard disk
1 A Sector is one section of a
track. It is colored blue in the diagram. It is the smallest unit of storage on the platter.
1 2 Tracks are the concentric circles 2
on the platter. The circles are smaller towards the center of the platter and larger towards the outer edge. The green ring is one track.
3 Clusters are groups of sectors 3
used to allocate the data storage area.
Logical structure of a magnetic disk
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The computer reads information from the hard disk through a fixed sensor called the disk head. The hard disk platters spin round underneath the disk head so that the computer can read the data tracks. A hard disk drive has a speed between 4500 and 10000 rpm (revolutions per minute), which means that the platters spin round between 4500 and 10000 times every minute. The boot sector is a special part of the disk that is used when the operating system starts. It contains a short machine language program that loads the operating system into RAM. When a hard disk is manufactured, the platters are empty, so your computer cannot read them. The process of creating the tracks and sectors on the platters and preparing the disk for use is called formatting. There are two types of formatting: low-level formatting and high-level formatting. The process of low-level formatting a drive creates the tracks and sectors on the platter. Low-level formatting writes the start and end points of each sector onto the platters. This process prepares the drive to hold blocks of bytes. Highlevel formatting writes special file storage structures (file system) onto the sectors. This process prepares the drive to hold files. The file system is the general name of the way of organizing files and the hierarchical arrangement of directories on the hard disk. Different operating systems use different file systems, such as FAT32, FAT64, NTFS, ext2, ext3, Reiser, and UFS. There are two ways to measure the performance of a hard disk: Data rate and seek time. The data rate is the number of bytes per second that the drive can send to the CPU. The data rate is usually between 5 and 40 megabytes per second. The seek time is the amount of time between when the CPU requests a file and when the first byte of the file is sent to the CPU. The seek time is usually between 10 and 20 milliseconds. Mobile devices’ HDDs are physically smaller than those of their desktop and enterprise counterparts. Desktop hard disks are 3.5 inches while portable hard disks are 2.5 inches or even smaller. The mobile devices’ hard disks tend to have relatively less capacity. A typical mobile HDD spins at 5,400 rpm, or 7,200 rpm.
Inside a 3.5-inch SATA hard disk
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A USB and network external storage box with 3.5-inch double hard disks
A 2.5-inch USB hard disk
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Solid-State Drive (SSD) A solid-state drive is a storage device that uses solid-state memory to store data. In contrast with traditional hard drives, solid-state drives contain no moving parts: no spinning platters, no moving heads. Data are split into word-length pieces and stored in memory. They are then accessed almost instantaneously using unique system-wide addresses. This behavior has been used in computer RAM for many years, but for a long time it was too expensive for using as a permanent storage solution. Solid-state technology is used in portable storage devices (USB flash memory, portable hard disk drives) and permanent storage devices (internal hard drives).
A 1.8-inch SSD
A USB flash drive is a flash memory data storage device integrated with a USB interface. USB flash drives are very popular because of their compactness. They actually act as portable hard drives. The storage capacities of USB flash memories can be as large as 1 TB, and higher capacity USB flash memories may emerge in near future.
USB flash drives
Solid-state drives may be preferred over traditional disk drives for a number of reasons: zzThe first advantage is the speed of operation. Because hard disk drives need to be spinning for the head to read sectors of the platter, sometimes you have to wait for spin up time. Once the disk is spinning, the head must seek the correct place on the disk, and from there, the disk must spin just enough so that the correct data are read. If data are spread over different parts of the disk (fragmented), then this operation is repeated until all the data have been read or written. It is often the case that reads from and writes to the hard disk create a bottleneck in a system. Because the information on solid-state drives can be accessed immediately (technically at the speed of light), there is no latency experienced when data are transferred. Because there is no relationship between spatial locality and retrieval speed, there is no degradation of performance when data are fragmented. 94
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zzThe second advantage is that breakdown is less likely. Because there are no moving parts, less can go wrong mechanically and dropping the drive is less likely to cause damage to the data. The drawbacks of solid-state drives are the capacity and cost. Because of the capacity and cost advantages of hard drives, they are still the market standard for storage devices.
Floppy Diskette (FDD) Floppy disks are also called diskettes. They are very slow compared to hard disks or CD-ROMs and hold a smaller amount of data (1.44 megabytes). Floppy disks are also quite fragile.
Inside a SSD
Floppy diskettes are not used any more and modern computers do not come with floppy disk drives.
Magnetic Tape Computers can read and write data on special cartridges of magnetic tape. A magnetic tape cartridge looks like a music cassette. Computer tape cartridges can be read only by a special tape drive. Tape drives use sequential access; thus, to access any particular piece of data, all preceding data must be read. Tape cassettes are often used as a backup medium suitable for the average PC user because tape cartridges are high capacity, inexpensive, and reliable as storage media.
A floppy diskette and floppy diskette drive
Various data cassettes in different sizes
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Zip Disk A zip drive is a small, portable disk storage capable of holding a moderate amount of computer information (100 MB or 250 MB). It is used primarily for backing up and archiving personal computer files.
A Zip disk looks like a floppy disk, but it can hold a lot more data (100 MB, 250 MB, or 750 MB). Zip disks can only be read by a special drive called a Zip drive. Zip disks were introduced by Iomega in 1995 and were popularly used until 2000. However, the Zip disk was never popular enough to replace the 3.5-inch floppy disk. Finally, USB flash drives became the common data storage and transfer medium among the general public due to common availability of USB ports built into personal computers.
CD ROM Disk A CD ROM (compact disc-read-only memory) is a type of optical disk capable of storing large amounts of data up to 1 GB, although the most common size is 700 MB.
A Zip disk and Zip drive
The CD ROM drive is used only to read the data from the CD disk. The data using the CD ROM cannot be written to the disk. For this purpose, the CD RW is necessary. CD RW is the rewritable drive that can perform both the functions of reading the disk as well as writing to the disk. The writing data to the disk is possible only with help of software called CD burner software. The process of writing the data or any information to the CD is called burning. The writing of the data is done all at a time. The data already written to the rewritable CD can be erased with the help of this software. However, there is no software that can partially erase the data. All currently available CD burner software requires the data to be completely erased and then burned over on the rewritable CD. However, the data can be written in multi-sessions. Currently, CD ROMs are used to back up of the important data or information of any kind.
CD ROM drive
The CD ROM currently has a capacity of about 700 MB. The extended CD ROM has a capacity of 800 MB. The highest CD ROM speed currently available is 52x. CD-Recordable drives are often sold with three different speed ratings, one for write-once operations, one for re-write operations, and one for read-only operations. The speeds are typically listed in that order, i.e., a 12x/10x/32x.
CD ROM disks
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DVD Disk DVD, also known as Digital Video Disc or Digital Versatile Disc, is an optical disc storage media format, invented and developed by Philips, Sony, Toshiba, and Time Warner in 1995. Its main uses are video and data storage. DVDs are of the same dimensions as compact discs (CDs) but are capable of storing much more data (about 4.7 or 8.5 GB of data on one side, or 17 GB on a disk with two sides). Newly available DVDs have a storage capacity of about 40 GB and even more. Because DVD-ROMs can store so much data, they are often used to store movies and animation. DVDs are available in different formats: DVD+R, DVD-R, DVD RAM, DVD RW, and so on. The DVD-R/RW means that the disk is recordable once and rewritable. DVD+R/RW means the same as DVD-R/RW. The “plus” and the “dash” formats use different writing specifications. Most DVD readers and players will play both kinds of discs, although older models can have trouble with the “plus” variants. DVD-ROM means that the disk is read-only memory. DVD-RAM is a random access rewritable, which means that after write checking, the integrity of the data is active. DVDs hold more data than CDs. DVD video format offers better picture and audio quality. Both CDs and DVDs are less expensive and more robust than hard disks. However, they are slower than hard disks and hold less data than hard disks.
A box of blank DVDs
DVD Type
Capacity (GB)
DVD 9
8.5
DVD 10
9.4
DVD 14
13.3
DVD 18
17.1
Different uses of DVDs
Blu-Ray Disk The Blu-ray disk is a high density optical storage medium. The Blu-ray format was developed to display high definition video (HD) and store large amounts of data by the Blu-ray Disc Association (BDA), a group of the world’s leading consumer electronics, personal computer, and media manufacturers (including Apple, Dell, Hitachi, HP, JVC, LG, Mitsubishi, Panasonic, Pioneer, Philips, Samsung, Sharp, Sony, TDK, and Thomson).
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Blu-ray is the successor to DVD. The disc has the same physical dimensions as standard DVDs and CDs. Blu-ray Disc uses a “blue” (technically violet) laser operating at a wavelength of 405 nm (nanometre) to read and write data. Conventional DVDs and CDs use red and near infrared lasers at 650 nm and 780 nm, respectively. The format offers more than five times the storage capacity of traditional DVDs and can hold up to 25GB on a single-layer disc and 50GB on a dual-layer disc. Recent development by Pioneer has pushed the storage capacity to 500 GB on a single disc by using 20 layers.
A HD movie on a blu-ray disk
List the names of your computer components and their properties. Use check marks to show the types of the components. Component Name
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Properties
Type
1
System Output Input Storage
2
System Output Input Storage
3
System Output Input Storage
4
System Output Input Storage
5
System Output Input Storage
6
System Output Input Storage
7
System Output Input Storage
8
System Output Input Storage
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Put a check () to show whether items below are portable or fixed. Device
Portable
Fixed
Match the words to compare computers and humans. Computer
Human
CPU
1
Eye
Speaker
2
Ear
RAM
Camera
3
Brain
Zip disk
Microphone
4
CD-ROM
Chassis
5
Hard disk
Floppy disk
2
Mouth Clothes
List the properties of each device in your computer. My Computer Device
Properties
Mainboard (type) Ports (number and type) CPU (type and speed) RAM (size in megabytes)
256 MB
Sound card (type)
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Take a price list from a computer sales company, imagine your dream computer and list the name and the price of each device. What is the total cost of your dream computer? Name
Price
1 2 3 4 5 6 7 8
T E A M A I N M W U K M H O O D C O P
I
S E A N T U I C K S I M R I S C S K E S D O D T N I
C E Y E
D O W O E B T Y B C R M A R Y A O M O O A O R T E R M A A R H R E R E T N I R P
1. Brain of the computer. 2. Temporary storage device 3. Output device that gives you a copy of your work. 4. 1048 Kbytes of information. TRANSISTOR 5. Another name for motherboard. 6. Physical parts of the computer. 7. 8 bits of information. 8. The most used output device. 9. Input device for typing. 10. The fastest permanent storage.
M E G A B Y T E D D
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1. The parts of computer that you can touch. 2. The _______________ Logic Unit (ALU) is the part
of the CPU that performs all of the calculations. 3. _________ Core processor contains 2 cores in one CPU. 4. ____________ Printers work similar to photocopy machines. 5. The __________ unit is the part of the cpu that controls the input and output devices. 6. A _______________ can capture images and texts from paper for computer editing and display. 7. __________ slots allow addition of new internal cards to a PC. 8. An Input device used to capture sound and voices. 9. An input device useful for playing games. 10. The CPU is often called the ___________ of a computer. 11. The ______________ memory is the closest and fastest memory for CPU.
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12. A __________ network uses radio signals and no wire.
13. ___________ ethernet allows speeds at 1000 Mbps on a network.
14. The CPU is made from a silicon ____________ . 15. __________ state Drive is a type of hard drive. 16. __________ supply provides current needed by the computer.
17. ___________ reader can be used to read black and white stripes on food packages.
18. It stores the data that tell the computer how to
load the operating system when it is switched on or re-booted. 19. A ________________ allows the computer to communicate with other computers by using telephone lines.
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Test Questions 1. What is the name of the hardware
used to take current from the electricity supply and convert it according to computer parts’ need?
a. Receive b. Converter c. PSU (Power Supply Unit) d. UPS e. Main board
2. The BIOS is actually a type of __________________ memory.
a. RAM b. ROM c. Virtual d. Static e. Temporary
3. ___________ bus is a high speed
bus generally used to describe the data path between the CPU and memory.
a. Universal Serial Bus (USB) b. Back Side Bus (BSB) c. Firewire d. Front Side (System) Bus (FSB) e. Power Bus
4. PCI buses, USB ports, and
IDE or SATA disc connections connect to the _________________ on a motherboard.
a. Southbridge Chipset b. Northbridge Chipset
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c. BIOS d. ISA Slots e. AGP Chipset
5. Which of the following peripheral
connection ports is the best option for reaching the highest data transfer rate?
d. L1 Cache Memory > L2 Cache Memory > RAM Memory > Virtual Memory e. L1 Cache Memory > Virtual Memory > L2 Cache Memory > RAM Memory
8. Which of the following is the full name for PC1066 RDRAM?
a. Parallel Port b. RS 232 c. USB 1.1 d. USB 2.0 e. USB 3.0
6. Jonah wants to buy a computer that has 8GB of RAM. To use that much RAM in his computer, how many bit CPU does he need?
a. 4 bit b. 8 bit c. 16 bit d. 32 bit e. 64 bit
a. Rambus Dynamic RAM at 1000 Mhz Speed b. Rambus Double RAM at 1066 Mhz Speed c. Rambus Data RAM at 966 Mhz Speed d. Rambus Dynamic RAM at 800 Mhz Speed e. Rambus Dynamic RAM at 1066 Mhz Speed
9. To install an internal sound card or TV card in your PC, you must have ______________________.
7. Which of the following is the
correct order of types of memory according to speed?
a. L1 Cache Memory > RAM Memory > L2 Cache Memory > Virtual Memory b. L2 Cache Memory > L1 Cache Memory >RAM Memory > Virtual Memory c. RAM Memory > L1 Cache Memory > L2 Cache Memory > Virtual Memory
a. a free PCI expansion slot b. a free AGP expansion slot c. a free RS232 port d. a free LPT port e. a free AMR slot
10. A computer can only understand
binary codes such as 01110011. To connect to the Internet, you have to use analog telephone signals to connected to ISP. Which of the following devices is used to convert the analog signal into a digital signal?
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Test Questions a. Network interface card (NIC) b. Modem (modulator/ demodulator) c. Sound card d. Graphic card e. Wireless ethernet card
11. Ruya’s teacher gave her a
printed full page text and asked her to scan it and change some of the text. Because she doesn’t have the softcopy of the printed text, she would like to scan the text and edit it on the computer. To perform this task, what operation must she perform after the scanning process, to create an editable text file?
a. CAD (computer aided design) b. DTP (desktop publishing) OCR (optical character c. recognition) d. Word processing e. Vector drawing design
a. Click – right click b. Scroll c. Drag and drop d. Double click e. Fast typing
17. Which of the following is the 14. You need to print 1500 pages of black and white printout for one of your projects. Which type of printer do you use to print them quicker and cheaper?
a. Desk jet printer b. Plotter c. Mono laser printer d. Dot matrix printer e. Color laser printer
15. Which of the following is not a
type of magnetic storage device?
a. Hard disk drive (HDD) b. Blu ray disk c. Tape d. Floppy disk e. Zip disk
12. What two devices do you need to record your voice into the computer?
a. Speaker - modem b. Speaker - graphics card c. Microphone – sound card d. Microphone – TV card e. Speaker - microphone
13. Which of the following cannot be performed with a mouse?
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d. Track >Platter > Cluster > Sector e. Platter > Track > Sector > Cluster
most common file system used in MS Windows Vista and Windows 7 Operating System?
a. FAT 16 b. FAT 32 c. NTFS d. ext2 e. ext3
18. You need to transfer several files
of about 4 GB each from one computer to another. What type of optical device do you need to perform this task? Suppose that you have only one disk.
a. CD-R b. CDRW c. DVD-R d. DVD RW e. DVD+R
16. Which of the following is the
correct order for parts of a hard drive according to size of data they can hold?
a. Platter > Track > Cluster > Sector b. Cluster > Platter > Sector > Track c. Platter > Sector > Track > Cluster
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Introduction Computer software gives instructions that make computer hardware work. In other words, software is a collection of computer programs and related data that provide the instructions for telling a computer what to do and how to do it. The four main types of software are operating systems, application programs, utility programs, and programming languages. zzAn operating system controls the workings of the computer and applications. MS-DOS, Windows, and Linux are examples of operating systems. zzAn application program is a program designed to help with a specific task, such as word processing, accounting, counting the items in a shop, or maintaining a database. Application software makes a computer work to suit the user’s needs. Microsoft Word, Lotus, and Paradox are some examples of application programs. zzA utility program is designed to help manage and tune the hardware, operating system, or applications by performing a single task or a small range of tasks. Some popular utility programs are PC Tools, Total Commander, Acronics Disk Manager, Norton Ghost, WinRar, and ACD See. zzA programming language is used to make application programs. Basic, Pascal, Java, and C++ are some examples of programming languages.
Software tells the computer what to do
Operating Systems An operating system is a piece of software that controls how hardware resources such as memory, the central processing unit (CPU), disk space, and other devices are used. All other kinds of software (application, utility, and programming) need the operating system because of hardware resources. An operating system has two parts, a kernel, and a shell. The kernel is the core of an operating system. It manages memory, files, and other devices; maintains the time and date; starts applications; and manages system resources. The shell provides direct communication interface between the user and the kernel. There are many different types of operating system. They are classified systems according to the type of user interface, how many users they support (single-user or multi-user), how they perform tasks (single task or multitask), and how they work with other computers (single computer or network). The layer structure
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The operating system is in the center of all the operations.
Interface The user interface is the part of the operating system used to enter commands and data. There are two types of user interface: command-line interface (CLI) and graphical user interface (GUI).
Other software accesses the hardware via the operating system.
A command-line interface does not use images or graphical menus. Instead, you type commands with the keyboard, using a special command language. Command-line interface systems tend to be more difficult to learn and use than graphical interface systems.
Copying a folder in a command-line interface
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A graphical user interface is a visual computer environment that represents files, folders, and programs with images such as icons, menus, and dialog boxes on the screen. You can select and activate these options by pointing and clicking with a mouse or by using the keyboard.
Copying a folder in a graphical user interface
Single or Multi-User A single-user operating system can be used only by a single user. A multiuser operating system can be used by more than one user. In some ways, a computer that several people share is like a multi-user system. However, a real multi-user system means a machine (and operating system) that several people can access at the same time, through communication facilities or network terminals. Server computers are multi-user systems whereas, PC’s or workstations are single-user systems.
A multi-user system
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Stand Alone or Network A network operating system is an operating system specifically designed to support computer networks. A computer network is a set of computers that can communicate with each other and share resources. A network operating system uses a special machine called a server to provide networking support for multiple simultaneous users as well as administrative, security, and management functions. Unlike a single-user operating system, a network operating system must respond to requests from many computers, managing network access and communications, resource use and sharing, data protection, and error control.
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Single or Multi-Tasking Single-tasking operating systems can work only on one task at a time. Multitasking operating systems can work on multiple tasks at the same time. They can be either cooperative or pre-emptive. In a cooperative multitasking system, the operating system waits for one task to voluntarily give control to another task. In a pre-emptive multitasking system, the operating system decides which task receives priority.
Multi-tasking operating systems simultaneously carry on many tasks.
MS-DOS MS-DOS is short for Microsoft Disk Operating System. MS-DOS is a singletask, single-user operating system with a command-line interface, which was released in 1981 for IBM PCs and similar PCs . DOS controls such operations as disk input and output, video support, keyboard control, and many internal functions related to running programs and maintaining files. It also allows users to organize files, load and execute (run) program files, and control the input and output devices attached to the computer.
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The windows command line interface can be accessed by running the cmd.exe that is located in the “system32” folder in your Windows folder. The most common way to access this interface is to type cmd in the run dialogue box, then click the OK button.
DOS uses a command-line interface to receive instructions and display results. Windows CMD (command prompt), cmd.exe, is a Windows program that acts as a DOS-like command line interpreter.
Windows CLI (command line interface)
Most Common MS-DOS Commands
Commands
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Meaning
VER
Displays the version of DOS that you are using.
DATE
Displays the current date and allows you to change it.
TIME
Displays the current time and allows you to change it.
CLS
Clears the screen.
DIR
Displays a list of the files and directories in the current directory.
C:\> F:
Changes the current drive from C to F.
COPY
Copies a file or folder from one place to another.
MOVES
Moves a file or folder from one place to another.
DEL
Deletes a file.
COPY CON
Creates a text file and enters text.
EDIT
A text editing program in which you can create, open, edit, and print text files.
CD
Changes directory. ICT - Information and Communication Technology
Documents Display the list of your documents using the MS-DOS commands.
Microsoft Windows Family Microsoft Windows is a series of operating systems produced by Microsoft. Windows was first introduced as an operating environment on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces (GUIs). The earlier version of Windows 3.1 was used for many years. Windows 95 was a revolutionary change in which windows introduced the Start button.
Windows 98 Windows 98 is a graphical operating system released on 25 June 1998 by Microsoft. It was a product based on MS-DOS. Windows 98 was succeeded by Windows Me. Windows 98 SE (Second Edition) was an updated release of Windows 98. It included fixes for many minor issues, improved USB support, included Internet connection sharing, and updated Microsoft NetMeeting 3.0 drives.
Interface of Windows 98 operating system
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Windows NT The Windows NT (New Technology) operating system was released by Microsoft Corporation in 1993. It is a completely self-contained operating system with a built-in graphical user interface. Windows NT is a multitasking operating system that has powerful networking, processing, and security features. It was designed specifically for office and business PCs and networks. Windows NT ran on a variety of hardware platforms based on the Intel 80386, i486, Pentium, and multiprocessor computers. Windows XP, Windows Vista, Windows 7, and Windows Server operating systems have been developed on the kernel of Windows NT.
Interface of Windows NT operating system
Windows Server Family Windows Server family is a brand name for a group of server operating systems released by Microsoft Corporation. This brand includes Windows 2000 Server, Windows Server 2003, Windows Server 2008, Windows Server 2008, Windows Server 2008 R2, and Windows Server 2012. Windows Server Operating systems were designed to replace Windows NT.
Windows XP Windows XP was built on the Windows 2000 kernel but with a new, more personalized graphical interface that makes it even easier to work with graphics and the Internet and to transfer files to other devices. Windows XP also allows different people to use their own system settings and files on the same computer.
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Windows Vista Windows Vista is an operating system developed by Microsoft for use on PCs including home and business desktops, laptops, tablet PCs, and media center PCs. Windows Vista was known by its codename Longhorn. On January 30, 2007, it was released worldwide. Windows Vista contains many changes and new features, including an updated graphical user interface and visual style Windows Aero, improved searching features, new multimedia creation tools such as Windows DVD Maker, and redesigned networking, audio, print, and display sub-systems. Windows Vista includes version 3.0 of the .NET Framework.
Windows Aero
Windows 7 Windows 7 is, as of March 2010, a series of operating systems produced by Microsoft. The server counterpart to Windows 7 Windows Server 2008 R2, was released at the same time. Windows 7 includes a number of new features, such as advances in touch and handwriting recognition, support for virtual hard disks, improved performance on multi-core processors, boot performance, Direct Access, and kernel improvements. This version of Windows includes Internet Explorer 8 and Windows Media Player 12. Windows Virtual PC was made available for Windows 7 Professional, Enterprise, and Ultimate editions. The Remote Desktop Protocol of Windows 7 is also enhanced to support real-time multimedia application including video playback and 3D games, thus allowing use of DirectX 10 in remote desktop environments.
Mac OS Mac OS is short for Macintosh Operating System. It is the commercial name of the Apple Macintosh operating system, which began with version 7.5 in September 1994, when Apple started licensing software to other computer manufacturers.
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Mac OS
In 1998, both Apple and Macintosh received a lot of publicity with the release of the iMac home computer. The Macintosh operating system has had different names: Finder, System 6, System 7, System 9, Mac OS, Mac OS X, and Mac OS X Lion.
Unix Unix is a multi-user, multitasking operating system. It was originally developed by Ken Thompson and Dennis Ritchie at AT&T Bell Laboratories between 1969 and 1973 for use on minicomputers. Unix has evolved into a complex, powerful operating system that is more portable and less machine specific than many other operating systems. Unix uses a powerful command-line interface, although there are also graphical user interfaces for the Unix system. There are many different versions of Unix, including System V, BSD Unix, A/ UX (a graphical version of Unix for the Macintosh), Linux (a newer Unix version that runs easily on home computers), and SunOS. Many versions of Unix are available for free. For some versions, the program code is also free, which means that software developers can help to improve and adapt the system. Unix is often used as a network operating system, especially for networks that use the Internet.
Linux Linux is a version of Unix System V developed for PCs with Intel 80386 and higher level microprocessors. Linux was first developed by Linus 114
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Torvalds, who gave the system his name, as well as many other software developers worldwide. Linux is free, and its program code can be changed by anyone who chooses to work on it, although some companies distribute it as part of a commercial package with Linux-compatible utilities. The Linux kernel works with a set of free Unix system utilities. Like Unix, Linux has a powerful command-line interface with some graphical user interface support. Linux is used as an operating system for network servers and has recently started to receive support from major companies such as IBM and Compaq.
Redhat LINUX
Novell NetWare Novell Inc. is a global software corporation based in the United States and specializing in enterprise operating systems such as SUSE Linux Enterprise and Novell NetWare; identity, security, and systems management solutions; and collaboration solutions. Novell superseded NetWare with Open Enterprise Server (OES) from 2005. The latest version of NetWare is v6.5 Support Pack 8, which is identical to OES 2 SP1, NetWare Kernel.
LINCOLN NetWare 5 Console Monitor
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BeOS and Haiku The BeOs graphical operating system was developed by Be, Inc. It was designed as a “media OS” that could support the large file sizes and highperformance processing demands of digital media and the Internet. BeOs can run on systems with two or more processors. Today, BeOS is largely used and developed by a small population of enthusiasts. The open-source Haiku is designed to pick up where BeOS left off.
Interface of BeOS and Haiku operating systems
Mobile Operating Systems The mobile platform, also referred to as mobile operating systems, manages the mobile device hardware, memory, and software resources. It controls the functioning and capabilities of a mobile device. The feature set, security, reliability, and ease of use are not the only criteria that make a mobile platform good or bad. How flexible the mobile platform is to integrate with diverse devices and software systems and how easy it is to build applications on it are also important factors. There are various types of mobile operating systems that power a variety of mobile devices from PDAs and smartphones to Tablet PCs. Below are some of the popular mobile platforms. Symbian OS Most of the mobile phones from Nokia run on Symbian operating system. However, Symbian has not been very successful as a smartphone operating system. Symbian is feature rich and is easy to use. A Symbian mobile phone can interface with several e-mail solutions.
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Google Android Android is a Linux-derived operation system supported by many major mobile companies like Google, HTC, Samsung, Motorola, and so on. It is generating a lot of interest among manufacturers, users, and application developers. It is an open platform that encourages developers to build their favorite applications with known tools and technologies. HTC was the first one to adopt android and was soon followed by Samsung and Motorola. The Android Mobile Platform is gaining so much ground so fast that almost all manufacturers are planning to launch their Android mobile phones. Android brings Google services like Google Search, Gmail, Google Maps, and YouTube to mobile devices. Mobile Linux Mobile Linux is the scaled down version of Linux operating system for mobile devices. It is an open operating system that powers many mobile phones and PDAs. Known for its reliability and robustness, Linux Mobile can also work with a diverse set of mobile devices. As with computers, there are many types of Linux operating system like LiMo for mobile devices. Nokia offers a couple of Linux mobile powered mobile phones. BlackBerry OS BlackBerry operating system is one of the most popular mobile platforms in the world. BlackBerry OS is an enterprise mobile device that can interface with various e-mail, calendar, notes, and contacts solutions. iPhone OS iPhone runs on Apple’s proprietary iPhone operating system, which is derived from Mac OS X. Currently, all iOS devices are developed by Apple and support an advanced touch and display technology.
iPhone 4s with iOS
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Which of the following tasks are performed by the operating system? (Choose three) 1
An operating system controls the workings of the computers.
2
An operating system is a program designed to help with a specific task, such as word processing and accounting.
3
An operating system controls the workings of the applications.
4
An operating system software is designed to help manage and tune the computer hardware.
5
An operating system uses application programs.
6
An operating system is a piece of software that controls hardware resources.
Research the usage of operating systems all over the world.
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APPLICATION PROGRAMS An application program is a program designed to help with a specific task, such as word processing, accounting, counting the items in a shop or warehouse, or maintaining a database. Application software makes a computer work to suit your needs. There are many different types of application programs. Microsoft Word a word processing program; Lotus a spreadsheet program; and Paradox , a database management system, are some examples of application programs.
Application programs designed to help with a specific task
Word Processor A word processor is an application program for text documents. It is like an electronic paper, pen, typewriter, eraser, and even a dictionary. Advances and developments in word processing applications support the WYSIWYG (what you see is what you get) technology. That is you see on the screen exactly what will appear when the document is printed. All word processors allow you to change text styles, page size, text spacing, and so on. Some word processors can also check spelling, find synonyms, incorporate graphics created with another program, write math formulas, create and print letters, perform calculations, display documents in different ways, and allow you to record special programs (macros) that perform complicated operations automatically. Some popular word processors are Microsoft Word, Corel WordPerfect, StarWriter, Windows WordPad, MacWrite, and WordStar. Chapter 3 - Software
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Put check (√) in the columns to compare a typewriter with a word processor. Complete the table. Action 1
You do not need a power supply.
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You can save and reuse your work.
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You can add pictures.
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You can make only a few copies.
5
You can make charts.
Typewriter
Word Processor
6 7 8
Open your WordPad program and write the paragraph below.
Spreadsheet A spreadsheet application helps you to organize text and numeric data, perform calculations, and organize charts. Spreadsheet programs organize data in cells, like the cells in a table. Some cells contain formulas, such as the sum of all the numbers in one column. If you change any number in the column, the value of the sum changes automatically. Spreadsheet programs are very useful in offices for accounting and for making financial plans and reports. Some popular spreadsheet programs are Microsoft Excel, Lotus 1-2-3, StarCalc, and Gnumeric. 120
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Open the Microsoft Excel program and make a chart to show the distribution of birthdays by seasons in your classroom.
Presentation Software Presentation software applications help you to create sequences of words and pictures that tell a story, or support a speech or a public presentation of information. Some popular presentation software applications are Microsoft PowerPoint, Lotus Freelance Graphics, Adobe Persuasion, OpenOffice.org Impress, Apple’s Keynote, and Corel Presentations.
Database Management Software Data are the raw material of information. The term refers largely to the information entered into and stored as a file within a computer. A database is a set of collections of data, for example, a set of information about the students in a class, with their names, ages, and grades.
Giving a presentation
The database includes all kind of data.
An example of database application
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A database program allows you to manage a database. It has four main parts: tables where the data is kept, forms that you use to enter data into the database, query that is a way to search the data, and reports that show the contents of the database. Some popular database programs are dBase, Paradox, Microsoft Access, FoxPro, Oracle, SQL Server, MySQL, InterBase, and Sybase.
Suppose that you are hired to make a database application to print the school reports of the students in your school. What kind of information would you need to record in your database (students’ names, school subjects, grades, etc.)?
CAD/CAM CAD/CAM is short for computer-aided design/computer aided manufacturing. CAD/CAM applications help people to design and manufacture products using computer-generated models. CAD/CAM is useful for engineers, scientists, and architects, who can develop models of cars, aircraft, integrated circuits, robots, tools, molecules, or even buildings using a computer. CAD/CAM applications create objects in two or three dimensions and show the results either as wireframe “skeletons”, as models with shaded surfaces, or as solid objects. Some programs can also rotate or resize models, show interior views, generate lists of the materials needed for construction, and perform other related tasks.
Sample models produced by some CAD/CAM programs
CAD/CAM programs use a lot of math, so they often need the computing power of a high performance workstation. The finished design is translated into a set of instructions that can be used by machines for manufacture, assembly, and process control. Some popular CAD/CAM programs are AutoCAD, ArchiCAD, MathCAD, and Electronic WorkBench. 122
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Painting and Drawing A painting program is an application program that creates graphics as a set of dots called a bitmap. Paint programs are particularly useful for freehand drawing, for example, drawing using a mouse or light pen. Painting programs usually include tools to create lines, curves, and geometric shapes that become part of the whole graphic. Some common painting programs are Windows Paint, Corel Painter, and Adobe Photoshop CS4. A drawing program allows you to create “object oriented” graphics instead of bitmaps. In an object-oriented graphic, you can move a part of the graphic, such as a line, a circle, or a block of text, as an independent object simply by selecting the object and moving it. Object-oriented graphics are created by combinations of lines, curves, circles, and squares. Some popular drawing programs are CorelDRAW and Adobe Illustrator. In the graphic design world, there are two main types of graphics: vector and raster (or bitmap). There are some major differences between the two graphic formats. Vector Graphics A vector graphic stores specific coordinates within your file as reference points, then records other information such as line gradients and thickness as a formula so, when you are editing a vector graphics file, you are not editing pixels on a screen, but you are adding to and altering the formula’s information. For that reason, vector graphics are completely scalable. It does not matter how small or how large your image is on the screen. Typical formats include EPS, AI, CDR, and SVG. Raster Graphics Raster graphic formats store information about the file as pixels. Pixels are small dots that are used to make up an image. The larger the resolution, the more pixels there are, and the bigger the file size of the image will be. There are different types of raster graphics used to compress file size using a range of different techniques. For example, GIF file format compresses file size of an image by simplifying color information of an image. It uses only 256 colors. JPEG is another raster image format that saves file size by using an algorithm that simplifies detail by analysis of pixel information. Both applications have their strengths and weaknesses. Raster graphic applications typically have a range of photo effects and photo editing functions. They make raster graphic application ideal for editing photos. In addition, raster graphics are more appropriate for any image for which you require a full color range. Vector graphics are more appropriate for drawing images from scratch, for example, for designing a logo from scratch or drawing a cartoon character.
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Vector and raster graphics
Major Graphic File Formats There are hundreds of image file types. The PNG, JPEG, and GIF formats are most often used to display images on the Internet. These graphic formats are briefly described below, separated into the two main families of graphics: raster and vector. In addition to straight image formats, Metafile formats are portable formats can include both raster and vector information. Examples are applicationindependent formats such as WMF and EMF. The metafile format is an intermediate format. Most Windows applications open metafiles and then save them in their own native format. Page description language refers to formats used to describe the layout of a printed page containing text, objects, and images. Examples are PostScript, PDF, and PCL. Raster Formats These formats store images as bitmaps (also known as pixmaps). zzJPEG: JPEG or JPG (Joint Photographic Experts Group) is a compression method. Nearly every digital camera can save images in the JPEG format, which supports 8 bits per color (red, green, blue) for a 24-bit total, producing relatively small files. zzTIFF: The TIFF (Tagged Image File Format) is a flexible format that normally saves 8 bits or 16 bits per color (red, green, blue) for 24-bit and 48-bit totals, respectively, usually using either the TIFF or TIF filename extension. Some digital cameras can save in TIFF format, using the LZW compression algorithm for lossless storage. TIFF image format is not widely supported by web browsers. TIFF remains widely accepted as a photograph file standard in the printing business. TIFF can handle device-specific color spaces, such as the CMYK defined by a particular set of printing press inks. OCR (Optical Character Recognition) software packages commonly generate some TIFF images for scanned text pages. 124
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zzPNG: The PNG (Portable Network Graphics) file format supports true color (16 million colors) while GIF supports only 256 colors. A PNG file excels when an image has large, uniformly colored areas. PNG is an extensible file format for the lossless, portable, well-compressed storage of raster images. PNG provides a patent-free replacement for GIF and can also replace many common uses of TIFF. Indexed-color, grayscale, and true color images are supported, plus an optional alpha channel. PNG is designed to work well in online viewing applications, such as web pages. zzAPNG: The APNG (Animated Portable Network Graphics) file format is an unofficial extension to the Portable Network Graphics (PNG) specification. It allows for animated PNG files that work similarly to animated GIF files while supporting 24-bit images and 8-bit transparency not available for GIFs. It also retains backward compatibility with non-animated PNG files.
Depending on the color mode used, a color image automatically has either three or four channels. The information within these channels specifies how much of each color is used to make the output color, such as orange, pink, and so on. These channels are standard in any color image. The alpha channel is an additional channel that can be added to an image. It contains transparency information about the image.
zzGIF: GIF (Graphics Interchange Format) is limited to an 8-bit palette or 256 colors. Thus, the GIF format is suitable for storing graphics with relatively few colors, such as simple diagrams, shapes, logos, and cartoon style images. The GIF format supports animation and is widely used to provide image animation effects.
zzBMP: The BMP file format (Windows bitmap) handles graphics files within the Microsoft Windows OS. Typically, BMP files are uncompressed; hence they are large; the advantage is their simplicity and wide acceptance in Windows programs
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Sketch
File Format
Size (KB)
.bmp
.gif
Draw a sketch in Microsoft Paint program. Save your sketch in different file formats and compare the file sizes. .jpeg
.png
Vector Formats As opposed to the raster image formats above (in which the data describe the characteristics of each individual pixel), vector image formats contain a geometric description that can be rendered smoothly at any desired display size. Vector graphics use geometric primitives such as points, lines, curves, and shapes or polygon(s), which are all based on mathematic equations, to represent images in computer graphics. zzCGM: CGM (Computer Graphics Metafile) is a file format for 2D vector graphics, raster graphics, and text. All graphical elements can be specified in a textual source file that can be compiled into a binary file or one of two text representations. CGM provides a means of graphics data interchange for computer representation of 2D graphical information independent of any particular application, system, platform, or device. It has been adopted to some extent in the areas of technical illustration and professional design, but has largely been superseded by formats such as SVG and DXF. 126
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zzSVG: SVG (Scalable Vector Graphics) is an open standard created and developed by the World Wide Web Consortium for a versatile, scriptable, and all-purpose vector format for the web and other environments. The SVG format does not have a compression scheme of its own, but due to the textual nature of XML, an SVG graphic can be compressed using a program such as gzip. Because of its scripting potential, SVG is a key component in web applications: interactive web pages that look and act like applications. zzDXF: DXF (Drawing Exchange Format) is a CAD data file format developed by Autodesk for enabling data interoperability between AutoCAD and other programs. DXF was originally introduced as part of AutoCAD 1.0 and was intended to provide an exact representation of the data in the AutoCAD native file format, DWG (Drawing). zzEPS: EPS (Encapsulated PostScript) is a PostScript document with additional restrictions and is intended to be usable as a graphics file format. In other words, EPS files are more or less self-contained, reasonably predictable PostScript documents that describe an image or drawing and can be placed within another PostScript document. zzPDF: PDF (Portable Document Format) is an open standard for document exchange. The file format created by Adobe Systems in 1993 is used for representing documents in a manner independent of the application software, hardware, and operating system. Each PDF file encapsulates a complete description of a fixed-layout 2D document that includes the text, fonts, images, and 2D vector graphics that comprise the documents. Today, 3D drawings can be embedded in PDF documents with Acrobat 3D. zzWMF / EMF: WMF (Windows Metafile) is a graphics file format on Microsoft Windows systems, originally designed in the early 1990s. Windows Metafiles are intended to be portable between applications and may contain both vector graphics and bitmap components. In 2007, Enhanced Metafile (EMF), a newer 32-bit version with additional commands, appeared. EMF is also used as a graphics language for printer drivers. The latest version of EMF, 4.0, appeared in 2008.
Page Layout and Desktop Publishing Desktop publishing combines a personal computer and WYSIWYG (what you see is what you get) page layout software to create publication documents on a computer for either large-scale publishing or small-scale local multifunction peripheral output and distribution. Many people use computers to create text and graphics for printing on a laser printer or a typesetting machine. This is called desktop publishing. The desktop publishing process involves different types of software and equipment. The original text and illustrations are usually produced with software such as word processors and drawing and painting programs and with scanners. A page layout application allows you to organize text and graphics on the screen and see what the results will be. Some popular page layout applications are Quark XPress, Adobe InDesign, Microsoft Publisher and Adobe Page Maker. Chapter 3 - Software
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Animation Programs Computer animation is the process of simulating the movements of computer graphics. It is created by displaying a series of pictures, at least 12 per second. Showing similar frames with little differences tricks the eye and brain into thinking they are seeing a smoothly moving object. Modern computer animation usually uses 3D computer graphics, although 2D computer graphics are still used for stylistic, low bandwidth, and faster realtime renderings. Making 3D animation in Autodesk 3DS Max
Computer animation is essentially a digital successor to the art of stop motion animation of 3D models and frame-by-frame animation of 2D illustrations. Computer-generated animations are more controllable than other more physically based processes, such as constructing miniatures for effects shots or hiring extras for crowd scenes, and allows creation of images that would not be feasible using any other technology. Some popular animation programs Adobe are Flash CS5, Microsoft Silver Line, 3D Studio MAX, Animation FX, 3D Maya, and Xara.
Adobe Flash is a common multimedia platform to produce animations.
Animation should be contrasted with video. While animations start with independent frames and display them one after another to form the illusion of continuous motion, video takes continuous motion and divides it into discrete frames.
Multimedia Applications Multimedia is the combination of sound, graphics, animation, and video formats of files. Multimedia applications allow you to play multimedia files, such as music and movies. This kind of application usually requires a DVDROM drive and writer, a sound card, a speaker, and a microphone. Multimedia files are very large, so they are usually recorded on DVD-ROMs. Some popular multimedia programs are Microsoft Media Player, Microsoft Media Center, Media Player Classic, Real Player, Quicktime Player, WinAmp, WinDVD, and PowerDVD.
Some examples of multimedia aplications
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Games Games allow you to interact with your computer as a form of entertainment. There are hundreds of different types of computer game, from simple alphabet games for small children, to chess, treasure hunts, war games, and simulations of world events. You can play games with a keyboard or with a joystick or other device. Games are supplied on DVD-ROMs, on game cartridges, or on the Internet. Some popular and famous games are Chess Master, Age Of Empires, SimCity, Fifa, Fifa Manager, Crysis Warhead, NFS Shift, and Counter Strike. Playing a video game
Educational Software The design of educational software programs for home use has been influenced strongly by computer gaming concepts; in other words, they are designed to be fun as well as educational. The following are examples of children’s learning software with a structured pedagogical approach, usually orientated towards literacy and numeracy skills. zzDisney Interactive learning titles based on characters such as Winnie-thePooh, Aladdin, and Mickey Mouse zzGCompris with numerous activities, from computer discovery to science zzKnowledge Adventure’s JumpStart and Blaster Learning System series zzThe Learning Company’s Reader Rabbit, The ClueFinders, and Zoombinis series Courseware Courseware is additional educational material intended as kits for teachers or trainers or as tutorials for students, usually packaged for use with a computer. Classroom Aids This category of educational software is designed for use in school classrooms and may be projected onto a large whiteboard or run simultaneously on a network of desktop computers. This type of software is often called classroom management software. Edutainment The merging of computer games and educational software into a single product is called edutainment. Edutainment products are developed not only to entertain people, but to educate them as well. Educational software on custom platforms The hardware and software is generally combined into a single product, such as a child-sized laptop-look alike.
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Online Applications Online applications are usually free, web-based word processor, spreadsheet, presentation, form, and data storage service that allow users to create and edit documents online while collaborating in real-time with other users. www. docs.google.com, www.acrobat.com, office.live.com, and www.zoho.com are some of the online applications.
An example of online Applications: www.zoho.com
Online Presentation Prepare an online presentation about a topic from the list below. • Your school activities • Your last vacation or trip • Your last birthday • Your classmates • The last book you read
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Software on your Computer List the names of the software on your computer. Software Word Processor
Name Microsoft Word 2007, WordPad
Spreadsheet Presentation Software Database CAD/CAM Painting and Drawing Page Layout Multimedia Online Applications Edutainment
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UTILITY programs What are Utilities? Utility software is a kind of system software designed to help analyze, configure, optimize, and maintain the computer. Utility software can clean your computer’s registry, recover lost or damaged data, generate free space on its hard drive, repair and defragment its hard drive, optimize system processes, and back up data. These applications address issues that can potentially decrease your computer’s efficiency, including registry and hard drive errors, unneeded files that clutter your disk space, security vulnerabilities, and inefficient system settings. Utility software should be contrasted with application software, which allows users to do things like creating text documents, playing games, listening to music, or surfing the web. Rather than providing these kinds of user-oriented or output-oriented functions, utility software usually focuses on how the computer infrastructure (including the computer hardware, operating system, application software and data storage) operates. Because of this focus, utilities are often rather technical and targeted at people with an advanced level of computer knowledge. Some popular utility programs are TuneUp Utilities, PC Tools, Total Commander, Windows Commander, Acronics Disk Manager, Norton Ghost, WinZip 12, WinRar, ACD See, and Adobe Acrobat Reader. Most major operating systems come with several pre-installed utilities. Some utility applications address specific problems. However, the best PC utilities manage a wide range of issues. Following are the most crucial types of utility applications.
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Disk Defragmenters Fragmentation occurs when the operating system cannot or will not allocate enough contiguous space to store a complete file as a unit, but instead, splits the data into smaller chunks and store them in separate locations. The more fragmented the data, the slower the operating system becomes. The disk defragmenter can detect computer files whose contents are broken across several locations on the hard disk and move the fragments to one location to increase efficiency.
Disk Checkers During their operations, different processes cause file system errors. Disk checkers can scan the contents of a hard disk to find files or areas that are corrupted in some way or were not correctly saved. Disk checkers eliminate them and remap the file system for a more efficiently operating hard drive.
Disk Cleaners After installing and uninstalling software packages, deleting the files, and using web browsers over a period of months, unnecessary files occupy a large space on your hard drive. Disk space consuming unnecessary files include temporary files, trash, old backups, and web caches made by web browsers. Disk cleaners can find and delete files that are unwanted or unnecessary to computer operation. The purpose of such deletion may be to free up disk space, to eliminate clutter, or to protect privacy.
Disk Space Analyzers Disk space analyzers are used to visual disk space usage by getting the size for each folder (including sub folders) and files in folders or the drive to show the distribution of the used space. Most of these applications analyze this information to generate a graphical chart showing disk usage distribution according to folders or other user-defined criteria.
Disk Partitions Disk partitioning is the act of dividing a hard disk drive into multiple logical storage units referred, to as partitions, to treat one physical disk drive as if it were multiple disks. Disk partition utilities can divide an individual drive into multiple logical drives, each with its own file system that can be mounted by the operating system and treated as an individual drive. A partition editor software program can be used to create, resize, delete, and manipulate these partitions on the hard disk.
Disk Compression Utilities Disk compression utilities are used to free up disk space. They can transparently compress and uncompress the contents of a disk, increasing the capacity of the disk. Chapter 3 - Software
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System Monitors and Profilers System monitors are used for analyzing the resources and performance of a computer. System profilers give detailed information about the hardware attached to the computer and software in use.
Antivirus Software A virus is a program that infects computer files by copying itself into files as they are loaded into memory. Viruses can spread very quickly through a whole computer or through portable devices and Internet files that people copy from one machine to another. Viruses often damage computers. For example, some viruses can destroy a computer’s hard disk or take up memory space that could be used by other programs. Some well-known viruses were Dark Avenger, Crazy Boot, Cascade, One Half, Yankee, Brain, Disk Killer, Nimda, Chernobil, ILoveYou, Win32, and Brontok.
Antivirus software programs
An antivirus program scans your computer’s memory and hard disks to identify and destroy viruses. It also examines files for viruses as your computer receives the files. Some common antivirus programs are Norton AntiVirus, McAfee, Dr.Web, Trend PC-Cillin, Kaspersky, Panda, Esset Nod32, AVG, Avira, and Symantec.
Registry Cleaners Each time you add or remove software, you make changes to your computer’s registry, which contains information and keys that tell the computer what to do in certain situations. Over time, this registry grows bigger and bigger. With all this registry clutter and wasted space, your computer’s performance will most likely suffer. Registry cleaners clean and optimize the Windows registry by removing old registry keys that are no longer in use. 134
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CleanMyPc can clean up the registry and improve performance.
Network Utilities Network utilities are used to monitor the computer’s network connectivity, configure network settings, analyze data transfer, or log events.
Backup Utilities
To backup data means making copies of data thus may be used to restore the original after a data loss event. Back up utilities can make a copy of all information stored on a disk and restore either the entire disk in case of a disk failure or selected files in case of an accidental deletion. Today, most of the laptop computers come with a backup utility. In case of a system failure, you can restore to factory settings.
Acronis True Image backup program
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File Managers A file manager is a computer program that provides a user interface to perform routine data management tasks. With the help of file managers, you can easily create, move, copy, view, print, merge, generate, rename, search, catalog, and delete files.
Total Commander file manager program
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PROGRAMMING LANGUAGES Introduction Programming is a kind of art and science of producing computer programs. Computer programs are written using a special language called the programming language. The writing process is called coding, and the result is called program code. Computer programmers need to know how to put instructions in a logical order (algorithm) and different types of interface, hardware, and operating system. They need to be able to think logically, like a computer.
Compiling and Interpretation A programming language is any artificial language that can be used to write instructions for a computer. Usually, programming languages need special programs, called compilers and interpreters, that translate the instructions (source code) into special code that the CPU and the hardware can process. This translation process is called compilation and interpretation. Compilers translate the source code into a machine executable file, and then the machine runs the translated file.
Compilation is like translating a text from one language to another language and reading it from the translated text. On the other hand, interpretation is like using a dictionary on each word in turn as you read from the original text.
General-Purpose and Special-Purpose Languages One way to categorize programming languages is according to whether the language is general purpose or special purpose. A language is considered general purpose if any program at all can be coded in the language. Conversely, if the language is targeted towards making certain kinds of things possible, it is considered “special purpose.” In computer software, a general-purpose programming language (GPL) is a programming language designed to be used for writing software in a wide variety of application domains. A general-purpose language does not include language constructs designed to be used within a specific application domain (e.g., a page description language contains constructs intended to make it easier to write programs that control the layout of text and graphics on a page). Some general-purpose languages are Assembly, BASIC, C / C++, C#, and Python. In software development and domain engineering, a domain-specific language (DSL) is a programming language or specification language dedicated to a particular problem domain, representation technique or particular solution technique. Examples of domain-specific languages include HTML, Logo for children, Verilog, and VHDL hardware description languages, Mathematica for symbolic mathematics, spreadsheet formulas and macros, SQL for relational database queries, Generic Eclipse Modeling System for creating diagramming languages, Csound for sound and music synthesis, and the input languages of GraphViz and GrGen.
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High-Level and Low-Level Languages Another way in which programming languages are sometimes categorized is by high-level or low-level languages. High-level programming languages have one high-level command or statement corresponding to many machine code instructions. Low-level programming languages, including especially assemblers, may have approximately one human-readable instruction per binary machine instruction. A low-level language is a programming language that is written for a particular set of hardware and processor and that uses few control instructions and data types. Each statement in a program written in a low-level language usually corresponds to one machine instruction. There is only one low-level language, called assembly language. A high-level language is a computer language that is more abstract than machine language. Statements in a high-level language usually use words similar to English and correspond to more than one machine language instruction. In practice, every computer language above assembly language is a high-level language. Some common high-level languages are Basic, Pascal,Java, and Cobol.
User Packages High Level Languages Low Level Languages Computer [Operating System] Software generation between user and computer
Web Programming Server-side scripting is a web server technology in which a user’s request is verified by running a script directly on the web server to generate dynamic web pages. It is usually used to provide interactive web sites that interface with databases or other data stores. Server-side scripting is different from client-side scripting in which scripts are run by the viewing web browser, usually in JavaScript. The primary advantage to server-side scripting is the ability to highly customize the response based on the user’s requirements, access rights, or queries of data stores. 138
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From a security point of view, server-side scripts are never visible to the browser because these scripts are executed on the server and emit HTML corresponding to user’s input to the page. When the server serves data in a commonly used manner, for example, according to the HTTP or FTP protocols, users may have their choice of a number of client programs. Most modern web browsers can request and receive data using both of those protocols. Some server-side scripting languages are ASP, C via CGI, ColdFusion Markup Language, Java via JavaServer Pages, JavaScript using Server-side JavaScript, Perl CGI, PHP, and Python via Django.
Some of the Popular Programming Languages Assembly Assembly language is a low-level programming language that uses abbreviations and codes to represent machine instructions. Each statement corresponds to a single machine instruction. An assembly language is translated to machine language by a program called an assembler. Although assembly language is difficult to learn, programs run faster and allow programmers to control hardware directly.
The following assembly program displays “Hello World”. pushdwordlen pushdwordmsg pushdword 1 moveax,0x4 call_syscall addesp,12 pushdword 0 moveax,0x1 call_syscall _syscall: int0x80 ret msgdb "Hello World",0xa lenequ $-msg PRINT "Hello World"
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Interface of assembly language
Each type of CPU has its own machine language and assembly language, so an assembly language program written for one type of CPU does not run on another. In the early days of programming, all programs were written in assembly language. Now, most programs are written in a high-level language such as Java or C++. Fortran Fortran is an acronym for Formula Translation. Fortran was the first highlevel computer language. It was developed between 1954 and 1958 by John Backus, an engineer at IBM. Fortran introduced important highlevel programming concepts such as variables, expressions, statements, and formatted input/output. Fortran was originally used in science and engineering, but it has developed over time to become a useful language for many different purposes. The following Fortran program displays “Hello World”. PROGRAM HelloWorld PRINT *, "Hello World" END PROGRAM HelloWorld 140
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BASIC BASIC is an acronym for Beginner’s All-purpose Symbolic Instruction Code. It is a high-level programming language developed in the mid-1960s by John Kemeny and Thomas Kurtz at Dartmouth College. Many people think that Basic is one of the easiest programming languages to learn because instructions are easy to read and similar to English. The following Basic program displays “Hello World”. PRINT
"Hello World"
Interface view of BASIC language
COBOL COBOL is an acronym for Common Business-Oriented Language. COBOL was developed between 1959 and 1961. Program instructions in COBOL look like English sentences, which means that COBOL is quite easy to understand. The COBOL 2002 standard includes features for object-oriented programming and other modern language features. The following COBOL program displays “Hello World”. IDENTIFICATION DIVISION. PROGRAM-ID.HELLO-WORLD. PROCEDURE DIVISION. MAIN. DISPLAY "Hello, world.". STOP RUN.
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Pascal and Object Pascal Pascal was developed between 1967 and 1971 by Niklaus Wirth. It was originally created to help people learn to program a computer. Pascal is a good general-purpose programming language. The following Pascal program displays “Hello World”. PROGRAM HelloWorld; BEGIN WRITELN(‘Hello World’); END.
Interface of PASCAL language
Object Pascal is a branch of object-oriented derivatives of Pascal, mostly known as the primary programming language of CodeGear Delphi. Pascal compilers, including Object Pascal, generally run extremely fast while producing highly optimized code. Borland used the name “Object Pascal” for the programming language in the first versions of Delphi, but later renamed it to the “Delphi programming language.”
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CodeGear includes development environments that compile the Delphi programming language to Microsoft Windows, the Microsoft .NET Framework, and Linux. The open source Free Pascal project allows the language to be compiled for operating systems, including Linux, Mac OS, Win32, and Win64.
Object-Oriented Programming means that different parts of a program are like objects that can be produced, destroyed, or changed and that can interact with each other. Object-oriented programming is very powerful because objects can be shared and used again and again. Non object-oriented programming is like building a car from the very beginning, from metal and bolts. Object-oriented programming is like using existing parts, such as an engine, the wheels, the body, and so on, to build the car.
The following Delphi And Free Pascal’s Object “Hello World”. programObjectPascalExample; type THelloWorld = class procedure Put; end; procedureTHelloWorld.Put; begin Writeln(‘Hello, World!’); end; var HelloWorld: THelloWorld; begin HelloWorld :=THelloWorld.Create; HelloWorld.Put; pointer} HelloWorld.Free; end.
Chapter 3 - Software
Pascal program displays
{this is an implicit pointer} {constructor returns a pointer} {this line dereferences the
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C, C++ and C# (C Sharp) The C programming language was developed by Dennis Ritchie at Bell Laboratories in 1972. It is called C because evolved from an earlier language called B. It has become very popular in office programming. It is closely associated to Unix, a popular industry operating system. It is a compiled language that contains a small set of functions that are machine-specific. The rest of the C functions are common to all machines. C programs are composed of one or more functions defined by the programmer. For this reason, C is called a structured programming language. The following C program displays “Hello World”. #include main() { printf("Hello World\n"); } C++ was developed as an object-oriented version of C by Bjarne Stroustrup in the early 1980s at Bell Laboratories. A visual programming version of C++ is Visual C++ The following C++ program displays “Hello World”. #include void main() { cout
