Tài liệu Giáo trình tiếng anh chuyên ngành công nghệ thông tin

BỘ GIÁO DỤC VÀ ĐÀO TẠO TRƯỜNG ĐẠI HỌC MỞ HÀ NỘI GIÁO TRÌNH TIẾNG ANH CHUYÊN NGÀNH CÔNG NGHỆ THÔNG TIN (ENGLISH FOR INFORMATION TECHNOLOGY) Chủ biên: Ths.Nguyễn Thị Thúy Lan GIÁO TRÌNH IN NỘI BỘ Hà Nội, 12/2021 BỘ GIÁO DỤC VÀ ĐÀO TẠO TRƯỜNG ĐẠI HỌC MỞ HÀ NỘI GIÁO TRÌNH TIẾNG ANH CHUYÊN NGÀNH CÔNG NGHỆ THÔNG TIN (ENGLISH FOR INFORMATION TECHNOLOGY) Tác giả: ThS. Nguyễn Thị Thúy Lan ThS. Thái Thanh Tùng Hà Nội, 12/2021 INTRODUCTION Nowadays English is one of the most common languages in the world. It is widely used in every sphere of life, especially in Information Technology. The aim of this book is to provide a basic knowledge of how English is used in Information Technology (IT). This book is designed particularly for the students in the Faculty of Information Technology of Hanoi Open University (FITHOU), who will use English not only for communicating but also for studying, researching and working in the future. It is a highly recommended material for those who want to improve their English proficiency in order to acquire a better basic knowledge in both English and English for Information Technology. There are 10 modules with 18 units covering major aspects of Information Technology using a variety of relevant materials taken from reliable sources such as specialized books and magazines. With the purpose of helping students to acquire the basic computing knowledge and English for IT, the emphasis is on developing reading, speaking and writing skills. Instruction on grammar and specialized language structures are also provided throughout the units. The book also includes a very useful glossary, as well as the answer keys and many teaching notes. It is designed as a user-friendly book with a clear layout, with many photos and graphics to illustrate the topics and better assist students in their study. The authors have devoted a lot of time and effort in compiling this book. Nevertheless, the book cannot escape from some shortcomings and the authors would like to apologise for any deficiencies found by readers. The authors would highly appreciate users‘ comments and remarks for further improvements in the next edition. Finally, the authors would like to express a sincere gratitude to Professor Thai Thanh Son, the former Dean of FITHOU for his valuable support in completion of this book. We hope that all teachers and students will find this book an interesting and useful resource. CONTENTS MODULE 1: COMPUTER TODAY ........................................................................... 1 UNIT 1: LIVING IN A DIGITAL AGE ...................................................................... 1 1.1. The digital age ................................................................................................... 1 1.2. Language work .................................................................................................. 3 1.3. Computers at work. ............................................................................................ 4 1.4. Other applications. ............................................................................................. 5 1.5 . Consolidation .................................................................................................... 6 UNIT 2: INTRODUCTION TO THE COMPUTER ............................................... 10 2.1. Definition of computer. ................................................................................... 10 2.2. Computer Types. .............................................................................................. 12 2.3. Reading ............................................................................................................ 14 2.4 Language work ................................................................................................ 16 2.5 Consolidation. .................................................................................................. 17 MODULE 2: INSIDE THE SYSTEM ....................................................................... 23 UNIT 3: THE CENTRAL PROCESSING UNIT (CPU) ........................................ 23 3.1 Technical specifications.................................................................................... 23 3.2 What is inside a PC system? ............................................................................. 23 3.3 Language work ................................................................................................ 26 3.4 How memory is measured? .............................................................................. 27 3.5.Consolidation .................................................................................................... 28 3.6. Vocabulary ....................................................................................................... 33 MODULE 3: INPUT AND OUTPUT DEVICES ..................................................... 34 UNIT 4. INPUT DEVICES ......................................................................................... 34 4.1 Interacting with your computer. ....................................................................... 34 4.2 Describing input devices................................................................................... 35 4.3. Language work: Describing functions and features. ....................................... 35 4.4 The keyboard .................................................................................................... 37 4.5. Mouse actions. ................................................................................................. 38 4.6. Consolidation . ................................................................................................. 39 4.7 Vocabulary. ....................................................................................................... 42 UNIT 5: OUTPUT DEVICES .................................................................................... 44 5.1 Screen Displays. ............................................................................................... 44 5.2 Printer................................................................................................................ 45 5.3 Speaker.............................................................................................................. 47 5.4 Projector. ........................................................................................................... 47 5.5 Plotter ................................................................................................................ 48 5.6. Consolidation. .................................................................................................. 48 5.7. Vocabulary ....................................................................................................... 50 MODULE 4: MEMORY AND STORAGE DEVICE .............................................. 52 UNIT 6: MAIN MEMORY AND TYPES OF MAIN MEMORY. ........................ 52 6.1 Main Memory. .................................................................................................. 52 6.2 Types of Main Memory. ................................................................................... 52 6.3 Primary Memory. .............................................................................................. 53 6.4 Computer memory and computer storages ....................................................... 54 6.5. Consolidation . ................................................................................................. 58 6.6. Vocabulary ....................................................................................................... 61 UNIT 7: STORAGE DEVICE .................................................................................... 62 7.1. Magnetic storage devices. ................................................................................ 62 7.2. Optical Storage ................................................................................................ 65 7.3 Flash memory ................................................................................................... 68 7.4 Consolidation. ................................................................................................... 73 7.5. Vocabulary. ...................................................................................................... 76 MODULE 5 : BASIC SOFTWARE ........................................................................... 78 UNIT 8: DEFINITION OF SOFTWARE ................................................................. 78 8.1 Definition of software. ...................................................................................... 78 8.2 Types of Software. ............................................................................................ 79 8.3. Consolidation . ................................................................................................. 80 8.4 Vocabulary. ....................................................................................................... 83 UNIT 9: TYPES OF BASIC SOFTWARE ............................................................... 85 9.1 System software ................................................................................................ 85 9.2 Application software. ........................................................................................ 91 9.3. Consolidation. .................................................................................................. 98 9.4.Vocabulary. ..................................................................................................... 102 MODULE 6: CREATIVE SOFTWARE ................................................................. 104 UNIT 10: GRAPHIC AND DESIGN ....................................................................... 104 10.1 Discussions related to computer graphics. ................................................... 104 10.2 Reading: Computer graphics ....................................................................... 104 10.3 Consolidation. ............................................................................................... 107 10.4. Vocabulary. .................................................................................................. 110 UNIT 11: DESKTOP PUBLISHING....................................................................... 111 11.1 Discussions related desktop publishing. ...................................................... 111 11.2. Reading: What is desktop publishing? ........................................................ 111 11.3 Consolidation ................................................................................................ 112 11.4. Vocabulary ................................................................................................... 116 UNIT 12: MULTIMEDIA ....................................................................................... 117 12.1. Multiple forms of multimedia. ..................................................................... 117 12.2. Multimedia magic!....................................................................................... 117 12.3. Consolidation. .............................................................................................. 119 12.4. Vocabulary. .................................................................................................. 123 UNIT 13. WEB DESIGN .......................................................................................... 124 13.1. A typical home page ................................................................................... 124 13.2. Web page design .......................................................................................... 124 13.3. Consodilation ............................................................................................... 127 13.4. Vocabulary. .................................................................................................. 130 MODULE 7: PROGRAMMING ............................................................................. 132 UNIT 14. INTRODUCTION TO PROGRAMMING AND PROGRAMMING LANGUAGES ............................................................................................................ 132 14.1 Introduction to programming. ....................................................................... 132 14.2 Programming Languages. ............................................................................. 134 14.3. Consolidation ............................................................................................... 140 14.4 Vocabulary .................................................................................................... 143 MODULE 8: NETWORK AND INTERNET ......................................................... 145 UNIT 15: DEFINITION AND TYPES OF NETWORK ....................................... 145 15.1 Definition Of Network. ................................................................................. 145 15.2 Types of Network. ........................................................................................ 147 15.3 Reading: Networking FAQs. ....................................................................... 148 15.4 Language work ............................................................................................. 151 15.5. Consolidation ............................................................................................... 154 15.6. Vocabulary ................................................................................................... 157 UNIT 16: INTERNET AND EMAIL ...................................................................... 159 16.1 Internet basics. .............................................................................................. 159 16.2 Reading : Internet FAQs .............................................................................. 160 16.3 Email features .............................................................................................. 163 16.4. Consolidation ............................................................................................... 164 16.5. Vocabulary. .................................................................................................. 167 MODULE 9: E-COMMERCE ................................................................................. 169 UNIT 17 : DEFINITION AND BENEFITS OF E-COMMERCE ........................ 169 17.1 Definition of e-Commerce ............................................................................ 169 17.2 Benefits of E- Commerce. ........................................................................... 169 17.3 Barriers to Business and Consumer Target Markets .................................... 170 17.4. Reading: Internet shopping: The inside story. ............................................. 171 17.5. Consolidation ............................................................................................... 172 17.6. Vocabulary. .................................................................................................. 176 MODULE 10: WORKING IN IT ............................................................................ 178 UNIT 18: IT JOB, DUTY AND YOUR FUTURE IN I.T ...................................... 178 18.1 IT Job and Duty. .......................................................................................... 178 18.2 Your future in IT. .......................................................................................... 179 18.3. Consolidation ............................................................................................... 181 18.4. Vocabulary ................................................................................................... 184 APPENDIX................................................................................................................. 186 1. Terminology.................................................................................................... 186 2. Acronyms and abbreviations .......................................................................... 218 REFERENCES .......................................................................................................... 224 MODULE 1: COMPUTER TODAY Learning objectives In this module you will: * Talk and write about computer applications in everyday life * Study the basic structure of a computer system * Study the differences between certain types of computers * Learn how to classify computer devices UNIT 1: LIVING IN A DIGITAL AGE 1.1. The digital age A. 1 2 3 4 B. C. Match the captions (1-4) with the pictures (a-d). In education, computers can make all the difference ___________ Using a cashpoint, or ATM ____________ The Internet in your pocket ____________ Controlling air traffic _________________ How are computers used in the situations above? In pairs, discuss your ideas. Read the following text and check your answers to B THE DIGITAL AGE We are now living in what some people call the digital age, meaning that computers have become an essential part of our lives. Young people who have grown up with PCs and mobile phones are often called the digital generation. Computers help 1 students to perform mathematical operations and improve their maths skills. They are used to access the Internet, to do basic research and to communicate with other students around the world. Teachers use projectors and interactive whiteboards to give presentations and teach sciences, history or language courses. PCs are also used for administrative purposes - schools use word processors to write letters, and databases to keep records of students and teachers. A school website allows teachers to publish exercises for students to complete online. Students can also enroll for courses via the website and parents can download official reports. Mobiles let you make voice calls, send texts, email people and download logos, ringtones or games. With a built-in camera you can send pictures and make video calls in face-to-face mode. New smartphones combine a telephone with web access, video, a games console, an MP3 player, a personal digital assistant (PDA) and a GPS navigation system, all in one. In banks, computers store information about the money held by each customer and enable staff to access large databases and to carry out financial transactions at high speed. They also control the cashpoints, or ATMs (automatic teller machines), which dispense money to customers by the use of a PIN-protected card. People use a Chip and PIN card to pay for goods and services. Instead of using a signature to verify payments, customers are asked to enter a four-digit personal identification number (PIN), the same number used at cashpoints; this system makes transactions more secure. With online banking, clients can easily pay bills and transfer money from the comfort of their homes. Airline pilots use computers to help them control the plane. For example, monitors display data about fuel consumption and weather conditions. In airport control towers, computers are used to manage radar systems and regulate air traffic. On the ground, airlines are connected to travel agencies by computer. Travel agents use computers to find out about the availability of flights, prices, times, stopovers and many other detail. ( Source: Infotech – English for computer users -4th edition) D. When you read a text, you will often see a new word that you don't recognize. If you can identify what type of word it is (noun, verb, adjective, etc.) it can help you guess the meaning. Find the words (1-10) in the text above. Can you guess the meaning from context? Are they nouns, verbs, adjectives or adverbs? Write n, v, adj or adv next to each word. 1. perform (line 4) ___________ 2. word processor (line 8) ______ 3 . online (line 10) ____________ 4. download (line 11) _________ 2 5. build-in (line 14) ___________ 6. digital (line 16) ____________ 7 . store (line 18) ______________ 8. financial (line 19) ___________ 9. monitor (line 28) ____________ 10. data (line 28) _______________ E. Match the words in D (1-10) with the correct meanings (a-j). a. keep, save ______ b. execute, do ______ c. monetary ________ d. screen __________ e. integrated ________ f. connected to the Internet ___________ g. collection of facts or figures ________ h . describes information that is recorded or broadcast using computers ______ i. program used for text manipulation _________ j . copy files from a server to your PC or mobile_________ F. In pairs, discuss these questions. 1. How are/were computers used in your school? 2. How do you think computers will be used in school in the future? 1.2. Language work: Collocations A. Look at the HELP box and then match the verbs (1-5) with the nouns (a-e) to make collocations from the above text . 1 2 3 4 5 give keep access enter transfer a b c d e money a PIN Internet presentations records Help Box Collocations 1 Verbs and nouns often go together in English to make set phrases, for example access to the Internet. These words combination are called collocations, and they are very common. Learning collocations instead of individual words can help you remember which verb to use with which noun. Here are some examples from the text. perform operations, do research, make calls, send texts, display data, write letters, store information, complete exercises, carry out transactions. 3 B. Use collocations from A and the HELP box to complete these sentences 1. Thanks to Wi-Fi, it's now easy to _____________ from cafés, hotels, parks and many other public places. 2. Online banking lets you _____________ between your accounts easily and securely. 3. Skype is a technology that enables users to _____________ over the Ințernet for free. 4.In many universities, students are encouraged to _____________ using PowerPoint in order to make their talks more visually attractive. 5.The Web has revolutionized the way people _____________ with sites such as Google and Wikipedia, you can find the information you need in seconds. 6.Cookies allow a website to _____________ on a user's machine and later retrieve it; when you visit the website again, it remembers your preferences. 7.With the latest mobile phones, you can _____________ with multimedia attachments - pictures, audio, even video. 1.3. Computers at work A. Read four people describing how they use their computers at work. What are their jobs? electrical engineer secretary librarian composer Peter: I write music mainly for videos and plays. I work on a keyboard connected to a computer. I use the computer in two ways, really, first of all, to record, or store, what I say on the keyboard. Secondly, the computer controls the sounds. I can make it with the different synthesizers I have here. I can use it to get different kinds of sound from the synthesizers. The computer is the link between the keyboard which I play, and the synthesizers, which produce the sounds. Peter’s job: ________________________ Anna : I use my computer to do the usual office things, like writing memos, letters, faxes and so on, but the thing I find most useful is e-mail. We‘re an international company, and we have offices all over the world. We‘re linked up to all of them by mail. With mail I can communicate with the offices around the world very efficiently. It has really changed my life. Anna’s job: ______________________ John : Well, I use computers for almost every aspect of my job. I use them to design electrical installations and lighting systems. For example, a program will tell 4 you how much lighting you need for a particular room, or how much cable you need, and it'll show where the cable should go. I also use the computer to make drawings and to keep records. We have to test our installations every five years, and that information is stored on the computer, too. John’s job: ________________________ Christina: I use computers to catalogue and classify all the materials received in the library, and record all the books, newspapers, DVDs, etc. that users borrow. I also assist customers and visitors in the use of IT hardware and software, including online databases and CD-ROMs. I help people with their enquiries, for example if children or elderly people need to find some specific information either in our online library catalogue or on the Internet. I'm also in charge of other library services, such as printing and fax machine. Christina’s job : _____________________ 1.4. Other applications. A . In small groups, choose one of the areas in the diagram below and discuss what you can do with computers in that area. Look at the Useful language box below to help you. 5 Useful language Formula 1 cars: design and build the car, test virtual models, control electronic components, monitor engine speed, store (vital) information, display data, analyze and communicate data. Entertainment: download music, burn CDs, play games, take photos, edit photos, make video clips, watch movies on a DVD player, watch TV on the computer, listen to MP3S, listen to the radio via the Web Factories and industrial processes: design products, do calculations, control industrial robots, control assembly lines, keep record of stocks (materials and equipment) School/University: access the Internet, enroll online, search the Web, prepare exams, write documents, complete exercises online, do research, prepare presentations -Computers are used to ………………… -A PC can also be used for……………… -People use computers to ………………. B. Write a short presentation summarizing your discussion. Then ask one person from your group to give a summary of the group's ideas to the rest of the class. 1.5 . Consolidation 1.5.1.Choose the best answer 1. How can computer become miraculous? A. due to CPU B. due to main memory C. due to hardware and software D. due to peripherals. 2. What are the results produced by a computer? A. input B. devices C. monitor D. information 3. Information in the form of data is call…………….. A. hardware B. software C. data D. peripheral 6 4. What has the same meaning as a monitor? A. Visual Display Unit B. Screen C. A & B D. None of the above 5. What are physical units that attached to the PC? A. hardware B. software C. data D. peripheral 6. What dose PC stand for? A. powerful Computer B. personal Counter C. Personal computer D. Pocket Computer 7. What is the program used for text manipulation? A. Spreadsheet B. Graphic design C. Word processor D. Animation 8. Results produced by the computer system is called ………… A. output B. input C. monitor D. port 9. The physical parts that make up a computer system is called ……………. A. software B. hardware C. peripheral D. data 10. What is Visual Display Unit? A. peripheral B. microprocessor C. disk D. drive 1.5.2. Fill in each blank with a suitable word below. digital that electronically thereby sound embedded 7 applications extensively scanners variety People use computers in a wide(1)…….…. of ways. In business, computers track inventories with bar codes and(2) …….., check the credit status of the customers, and transfer funds(3)…….……..In home, tiny computers(4)…..….. in the electronic circuitry of most appliances control the indoor temperatures, operate home security systems, tell the time, and turn video-cassette recorders on and off. Computers in automobiles regulate the flow of fuel, (5)……. …….increasing gas mileage. Computers also entertain, creating digitized sound on stereo systems or computeranimated features from a(6)……..encoded laser disc. Computer programs, or (7)……..…….., exist to aid every level of education, from programs(8)……..….. teach simple addition or sentence construction to advanced calculus, educator use computers to track grades and prepare notes; with computer control projection units, they can add graphics,(9)……..…. and animation to their lectures. Computers are used (10)…..…….. in scientific research to solve mathematical problems, display complicated data. 1.5.3. Read and translate the following passage into Vietmamese Sal has all the necessary qualities for becoming a good telemarketer. He's bright, outgoing and persistent. He is also blind. Phyllis wants to hire him, but she has some concerns. How will he be able to use the company's database if he can't see the monitor? How will he read office correspondence? And more important, what will it cost the company to adapt the workplace to accommodate him? A disabled person using a voice command-activated computer at the Center for the Handicapped in Seattle. He operates the system with a headset microphone, muscle switches and a joystick control. A blind student using an adapted keyboard, in the presence of his tutor. The headphones and a screen reading program allow him to hear the text from the screen Phyllis must accommodate him, since' her company is in the US, and therefore subject to the Americans with Disabilities Act or ADA. But she needn't worry. The latest adaptive technology for personal computers provides a cost-effective way to allow Sal and workers with other disabilities to do their job with independence. The first task in adding adaptive technology to a computer is to determine the specific needs of the disabled worker in question. To work effectively most blind users need to have their computers adapted with technologies such as speech synthesis, magnification, Braille and OCR. One example of a speech-synthesis system is VertPro from TeleSensory. This product can read MS-DOS-based word processors, databases, spreadsheets, and other text-based software. Window Bridge from Syntha-Voice can verbalize both MS-DOS and Windows-based applications. For someone with limited but usable vision, a software magnification package may be appropriate. Magnification software can enlarge text appearing on the screen by up to 16 times. 8 For Braille output, the Juliet printer from Enabling Technologies interfaces to any standard serial or parallel port. This printer can emboss Braille on both sides of a page at a speed of 40 characters per second. The Reading Edge OCR from Xerox Imaging Systems and the Arkenstone Open Book Unbound from Arkenstone can read printed material to blind people and send the text to a PC. Bob Love was born with no arms. He uses an overlap keyboard with his feet and the computer and monitor on the floor. The key overlays give a much larger surface for each key. (Source: English for Information Technology. Oxford University Press) 1.6. Vocabulary Essential (adj) chính, chủ yếu, quan trọng, cần thiết Interactive (adj) điều hướng Database (n) Cơ sở dữ liệu Enroll (v) ghi danh, đăng kí built-in (adj) tích hợp navigation (n) sự điều hướng financial (adj) thuộc về tài chính transaction (n) sự giao dịch cashpoint (n) máy rút tiền tự động ( máy ATM) transfer (v) chuyển consumption (n) sự tiêu thụ Installation (n) sự lắp đặt, cài đặt Virtual (adj) ảo Mechanism (n) cơ chế, cơ học Record (n) bản ghi (dữ liệu) Disabled (adj) tàn tật, khuyết tật Telemarketer (n) nhân viên tiếp thị qua điện thoại Concern (n) mối quan tâm Correspondence (n) báo chí Magnification (n) sự phóng đại 9 UNIT 2: INTRODUCTION TO THE COMPUTER 2.1. Definition of computer Input Data is collected and entered Processing Output Data is manipulated The results are shown on the monitor or in print form Storage Files and programs are held on disk Expenses (e.g payroll, services publicity) Balance Income (e.g sales, stock, interest) Fig 1 A. Read the text and then explain Fig.1 in your own words What is a computer? A computer is an electronic machine which can accept data in a certain form, process the data, and give the results of the processing in a specified format as information. 10 First, data is fed into the computer's memory. Then, when the program is run, the computer performs a set of instructions and processes the data. Finally, we can see the results (the output) on the screen or in printed form (see Fig.1 above). A computer system consists of two parts: hardware and software. Hardware is any electronic or mechanical part you can see or touch. Software is a set of instructions, called a program, which tells the computer what to do. There are three basic hardware sections: the central processing unit (CPU), main memory and peripherals. Perhaps the most influential component is the central processing unit. Its function is to execute program instructions and coordinate the activities of all the other units. In a way, it is the 'brain' of the computer. The main memory (a collection of RAM chips) holds the instructions and data which are being processed by the CPU. Peripherals are the physical units attached to the computer. They include storage devices and input/ output devices. Storage devices (hard drives, DVD drives or flash drives) provide a permanent storage of both data and programs. Disk drives are used to read and write data on disks. Input devices enable data to go into the computer's memory. The most common input devices are the mouse and the keyboard. Output devices enable us to extract the finished product from the system. For example, the computer shows the output on the monitor or prints the results onto paper by means of a printer. On the rear panel of the computer there are several ports into which we can plug a wide range of peripherals - a modem, a digital camera, a scanner, etc. They allow communication between the computer and the devices. Modern desktop PCs have USB ports and memory card readers on the front panel. A USB port A USB connector (Source: Infotech – English for computer users -Forth edition). B. Match these words from the text (1-9) with the correct meanings (a-i). 1 Software a the brain of the computer 2 peripherals b physical parts that make up a computer system 3 main memory c programs which can be used on a particular computer 11 4 hard drive (also known as hard disk) 5 hardware 6 input 7 ports 8 output 9 central processing unit (CPU) system d the information which is presented to the computer e results produced by a computer f input devices attached to the CPU g section that holds programs and data while they are executed or processed h magnetic device used to store information i sockets into which an external device may be connected 2.2. Computer Types. In this unit you will learn about different types of computers and what makes them unique. Computers were not always things you could carry around with you, or even have in your bedroom. Sixty years ago, computers (such as ENIAC) were as big as entire apartments. They were difficult to use and not very powerful by today‘s standards. They also cost a lot of money to build and operate. So computers were only used by large organizations such as governments, international corporations, and universities. Throughout the 1950s and 1960s, computers captured the public's imagination in literature, films, and TV. More and more companies wanted computers, even if they didn't always have a good reason to own one. As a result, computers gradually became smaller, cheaper, and more practical to own. This was thanks in part to companies like IBM, which mass-produced computers for the first time and promoted them to medium and large businesses to do things like payroll, accounting, and other numbercrunching tasks. In the 1970s and 1980s a new type of computer started to gain in popularity. It was called the PC or personal computer. For the first time in history, computers were now for everyone. The PC started a revolution which affects nearly everything we do today. The ways we work, play, communicate, and access information have all been radically reshaped due to the invention and evolution of the PC. PCs are everywhere you look today: at home, at the office, and everywhere in between. Many people still mistakenly believe the term PC is synonymous with a desktop computer running Windows. This is not really true. Really, any computer you use by yourself for general purposes could be called a PC. You probably already own at least one of these types of PCs: laptop desktop computer 12 PDA or personal digital assistant workstation Besides PCs, there are other types of computers you probably see at work or school. These include:  file servers web servers But not all types of computers are as obvious as the ones above. There are still other kinds of computers that fit inside of other devices and control them. These computers are known as embedded systems. Embedded systems can be found in traffic lights, TV sets, refrigerators, coffee machines and many more devices. Embedded systems are typically controlled by inexpensive, specialized processors which can only handle very specific tasks. Types of computers go in and out of fashion as time changes. Older kinds of computers which were very popular in the 20th century (1900's) are now referred to as legacy systems. These include: mainframes minicomputers IBM clones Fig.1.1 Mainframe Fig.1.2. Minicomputer 13 Fig.1.3. IBM clone