Tài liệu giảng dạy Tiếng Anh chuyên ngành Công nghệ thông tin (English for Information Technology) được biên soạn gồm 7 units, cụ thể như sau: Unit 1: Computer uses, unit 2: Types of computer, unit 3: Keyboard and mouse, unit 4: Input devices, unit 5: Output devices, unit 6: Storage devices, unit 7: Networks. Mời các bạn cùng tham khảo.
BỘ CƠNG THƯƠNG TẬP ĐỒN DỆT MAY VIỆT NAM TRƯỜNG CAO ĐẲNG CÔNG NGHỆ TP.HCM _ KHOA NGOẠI NGỮ - TIN HỌC TÀI LIỆU GIẢNG DẠY TIẾNG ANH CHUYÊN NGÀNH CÔNG NGHỆ THÔNG TIN ENGLISH FOR INFORMATION TECHNOLOGY TP HCM LƯU HÀNH NỘI BỘ English for Information Technology UNIT 1: COMPUTER USES Task We use computers in many different places In groups, make a list of places where we can find computer documents Try to say what the documents are, and what they are used for Task Match these words (1 -8 ) to the correct locations ( a- d) games a a factory machines b a supermarket tickets c a travel agent wages d a home fight letters barcode readers tills READING: COMPUTERS IN EVERYDAY LIFE Computers are parts of our everyday lives They have an effect on almost everything you When you buy groceries at a supermarket, a computer is used with laser and barcode technology to scan the price of each item and present a total Barcoding items (clothes, food, and books) requires a computer to generate the barcode labels and maintain the inventory Most television advertisements and many films use graphics produced by a computer In hospitals, beside terminals connected to the hospital’s main computer allow doctors to type in orders for blood tests and to schedule operations Banks use computers to look after their customers’money In libraries and bookshops, computers can help you to find the book you want as quickly as possible Task Tick ( + ) the computer uses mentioned in the above article home - art hospitals - banking engineering - libraries shopping - film-making television advertising - schools Language work: Articles ( with countable and uncountable nouns) Language work: Articles ( with countable and uncountable nouns) Study these nouns a supermarket technology a computer money supermarket and computer are countable nouns We say a supermarket and supermarkets Technology and money are uncountable nouns English for Information Technology They have no plural and you cannot use them with a or an Study this paragraph Computers have many uses In shops a computer scans the price of each item Then the computer calculates the total cost of all the items - We use a plural noun with no article, or an uncountable noun when we talk about thing Ex: Computers have many uses Information technology is popular - We use a / an when we mention a countable noun for the first time - When we mention the same noun again, we use the - We use the with countable and uncountable nouns to refer to specific things Ex: The price of each item The total cost of all the items The speed of this computer Task Here are some common nouns in computing Divide them into countable and uncountable nouns capacity data device disk drive memory monitor mouse software 10 speed Task Fill in the gaps in this paragraph with a/ an or the where necessary The Walsh family have _ computer at home Their son uses _computer to help with homework and to play _computer games Their student daughter uses computer for _ projects and for email All family use it to get _information from Internet Task Match the places in column A with the computer uses in column B A Banks Factories Homes Hospitals Shops B Control machines Calculate Look after, patient records and medicines Provide entertainments and information Control our money Task Now fill in the gaps in this paragraph about computer uses Computers are now part of our everyday life In shops, they ……………… In factories, they……………………… .In …………………… they look after patient records and medicines When we have a bank account, a computer …………………… In our homes computers …………………… English for Information Technology Reading comprehension USES OF COMPUTER TECHNOLOGY Computer technology is now seen in almost every activity In addition to its extensive use in research and control systems of all types, it is exploited in education and training, police and intelligence, medical diagnostic, weather forecast… It is changing our world from a natural-based economy to an informative-based economy In business, computers are programmed to bill customers, take inventory, pay employees, help with managerial decision…They can replace people in dull, routine tasks and enable “office automation” but they have no originality: they work under instructions given to them by programmers They have no intuition and no creation, i.e they can only proceed as they have been programmed to Answer the questions: Is Computer technology now seen every activity? Give examples? Translate the phrases: natural-based economy, informative- based economy Translate the paragraph into Vietnamese Further reading COMPUTER APPLICATIONS - Computer can help students perform mathematical operations and solve difficult questions They can be used to teach courses such as computer- aided design (CAD), language learning, programming, mathematics,….etc PCs (personal computers) are also used for administrative purposes: for example, schools use databases and word processors to keep record of students, teacher and material… - Bank use computer to look after client’s money Computer also helps staff to access large database and carry out financial transaction at high speed They also control the automatic cash dispensers which, by the use of a personal coded card, dispense money to clients - In business, computers support a lot for management to make report, presentation, plan budget and to have an overview of revenue and expenditure of the entities Accountants also use computer to record accounting and prepare the salary for staffs as well as related operations - Airline pilots use computer to help them control the plane For examples, 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, price, and times, stopovers and many other details Answer the questions: What can computer help students? What can they be used for? English for Information Technology Why does bank use computers? What are computers used in business for? Give examples to show that computers are used in air traffic? THE COMPUTER A computer is a machine with an intricate network of eletronic circuits that operate switches or magnetize tiny metal cores The switches, like the cores, are capable of being in one of two possible states, that is, on or off; magnectized or demagnetized The machine is capable of storing and manipulating numbers, letters, and characters The basic ideas of a computer is that we can make the machine what we want by inputting signals that turn certain swithches on and turn others off, or that magnetize or not magnetize the cores The baisc job of computers is the processing of information For this reason, computer can be defined as devices which accept information in the form of instructions called a program and charaters called data, perform mathematical and/or logical operation on the information, and then supply results of theses operations The program, or part of it, which tells the computers what to and the data, which provide the information needed to solve the problem, are kept inside the computer in a place called memory Computers are thought to have many remarkable powers However, most computers, whether large or small have three basic capabilities First, computers have circuits for performing arithmetic operations, such as: addition, subtraction, division, multiplication and exponentiation Second, computers have a means of communicating with the user After all, if we couldn’t feed information in and get results back, these machines wouldn’t be of much use However, certain computers ( commonly minicomputers and microcomputers) are used to control directly things such as robots, aircraft navigation systems, medical instruments, etc Some of the most common methods of inputting information are to use punched cards, magnetic tapes, disks, and terminals The computer’s input device ( which might be a card reader, a tape drive or disk drive, depending on the medium used in inputting information) reads the information into the computer For outputting information, two common devices used are a printer which prints the new information on paper, or a CRT display screen which shows the results on a TV-like screen Third, computers have circuits which make decisions The kinds of decisions which computer circiuts can make are not of the type: “ Who would win a war between countries?” or “ Who is the richest person in the world?” Unfortunately, the computer can only describe three things, named: Is one number less than another? Are two numbers equal? and, Is one number greater than another? A computer can solve a series of problems and make hundreds, even thousands, of logical decisions without becoming tired or bored It can find the solution to a problem in a fraction of the time it takes a human being to the job A computer can replace people in dull, routine tasks, but it has no originality; it works English for Information Technology according to the instructions given to it and cannot exercise any value judgements There are times when a computer seems to operate like a mechanical” brain”, but its achievements are limited by the minds of human beings A computer cannot anything unless a person tells it what to and gives it the appropriate information: but because electric pulses can move at the speed of light, a computer can carry out vast numbers of arithmeticlogical operations almost instantaneously A person can everything a computer can do, but in many cases that person would be dead long before the job was finished Main ideas Which statement best expresses the main idea of the text? Why did you eliminate the other choices? Computers have changed the way in which many kinds of jobs are done Instructions and data must be given to the computer Computers are machines capable of processing and outputting data Without computers, many tasks would take much longer to Understanding the passage Decide whether the following statements are true or false( T/F) by referring to the information in the text Then make the necessary changes so that the false statements become true A computer can store or handle any data even if it hasn’t received information to so All computers accept and process information in the form of instructions and characters The information necessary for solving problems is found in the memory of the computer Not all computers can perform arithmetic operations, make decisions, and communicate in some ways with the users Computers can still be useful machines even if they can’t communicate with the users There are many different devices used for feeding information into a computer There aren’t as many different types of devices used for giving results as there are for accepting information Computers can make any type of decisions they are asked to Computers can work endlessly without having to stop to rest unless there is a breakdown Read the text again and try to find out what the bold words refer to that operate switches which accept information or part of it English for Information Technology which tells the computer which prints the new information which shows the results which can make decisions it can be find the solution it has no originality 10 tells it what to Translate the text into Vietnamese English for Information Technology UNIT 2: TYPES OF COMPUTER Task Match these names to the different types of computer mainframe laptop notebook handheld 5.PC minicomputer Task Study these details of different types of computer Find the answers to these questions Which type of computers is: the most common? small enough for a pocket? the most common portable? used by many people at the same time? used like mainframes? also called a handheld computer? the most powerful? not suitable for a lot of typing? Types of computer Mainframes Minicomputers Notes Large, powerful, expensive Multi-user systems- used by many people at the same time Used for processing very large amounts of data The most powerful mainframes are called supercomputers Used like mainframes Not as big, powerful, or expensive as mainframes Less common now because microcomputers have English for Information Technology improved Microcomputers or The most common type of computer Personal computers Smaller, cheaper, and less powerful than mainframes and (PCs) minicomputers Types of portable Notes Laptop About the size of a small typewrite Less common now because smaller and lighter portable are available Notebook About size of a piece of writing paper The most common type of portable Subnotebook Not quite as big as notebooks Can fit into a jacket pocket Handheld and Palmtop Small enough to fit into the palm of one hand Not easy to type with because of their size Often used as personal organizers Task In pairs, decide what sort of computer is best for each of these users John Wilmott is a salesperson and he spends a lot of time visiting customers He wants a computer to carry with him so he can access data about his customers and record his sales Pat Nye is a personnel officer She needs a computer to keep staff records and to keep a diary of appointments She also needs a computer for writing letters The University of the North needs a computer to look after its accounts, its network, the records of all student and staff and to help with scientific research The James family want a computer for entertainment writing letters, the Internet, and for calculating tax Language work: Comparisons Equal comparisons Comparatives Superlatives Task Choose the correct adjective Then fill in the gaps with the correct form of the adjective a Laptops are ……………………… than desktop computers but ……………… than notebooks (light / heavy) b The mainframe is the …………………….type of computer A minicomputer is …………………….than a microcomputer (large / small) English for Information Technology c Personal computers are ……………………….than mainframes but mainframes are …………………… than personal computers at processing very large amount of data ( common / good) d Minicomputers are …………………………… than mainframes but they are also……………………… (powerful / expensive) e New computers are ……………………and sometimes ………………………… than older machines (fast / cheap) f Laptops are often ………………………than PCs but they are not as ……………………………………… ( powerful / expensive) Task Put the words in brackets into the correct form to make an accurate description of sizes of computers There are different types of computer The (large) …………………….and (powerful)2………………………….are mainframe computers Minicomputers are (small) 3……………………… than mainframes but they are still very powerful Microcomputers are small enough to sit on a desk They are the (common) …………………….type of computer They are usually (powerful) 5………………………….than minicomputers Portable computers are (small) 6……………………… than desktop The (large) 7…………………portable is a laptop (Small) 8…………………….portables, about size of a piece of writing paper, are called notebook computers Subnotebooks are (small)9………………….than notebooks You can hold the (small) 10 ………………… computers in one hand They are called handheld computers or palmtop computers Reading Comprehension THE COMPUTER INDUSTRY Information processing The computer technology INFORMATICS is a study of the ways of processing information by the use of a computer machine The processing of information includes the collection of instruction (or programs) and inputs ( or data), and the manipulation, storage, retrieval and communication of data The processing of data is carried out by: - Hardware industry, or business that designs, manufactures, or repairs the physical, electronical and electromechanical parts of computer sets - Software industry , or business that provide programs to direct the processing of data by coordinating the activities of the hardware * Note: Firmware is only the system software that is stored inside the computer ROM Do not confound this with any computer industry Answer the questions: What is informatics? 10 English for Information Technology a line, and lines on a page One of the most difficult parts of printing output is the reaction of the user to the printed page, because somehow the printed output produces a response from the reader much like that of people to a roomful of new furniture They have definite ideas where each piece should go, but after seeing it there, they are apt to change their minds The same occurs when the reader first sees the printed output of a report, for instance No matter how simple or complex the data-processing operation is, the final results must be made available in a form usable by humans, and usually in a form of permanent record This is the purpose of the printers used with computing equipment Printers vary in speed, size, and cost, and are designed to meet printing requirements ranging from roughly the speed and volume of a typewriter up to thousands of lines per minute There are two ways of printing: by impact ( striking a character through a carbon, like a typewriter) or non-impact ( photocopying, like an office copier) Impact printers are generally a drum, or a chain or a train The drum has a spining cylinder for each character position in a line, and each cylinder contains all the characters in a character set As each cylinder spins into the appropriate character position, it is hammered into the paper through a carbon ribbon Drum printers generally give the lowest quality printing, because if the hammer hits a little early or late, the character will appear slightly above or below the line This is noticeable on a printed line, giving it a wavy appearance In train or chain printers, the characters move lately across the page, and as the proper character moves into position, it is hammered onto the paper through a carbon ribbon If the hammer hits a little early or late, character will appear slightly to the right or left of its proper position, but variations in horizontal spacing are not noticeable to humans Other types of impact printers are the daisy wheel printer, the matrix printer, and the line printer The daisy wheel printer uses a wheel with up to 100 characters, each being on an individual arm, so that only rotation is needed The hammer hits a single letter, guaranteeing accurate positioning and uniform striking This allows fast, quiet, and reliable operation, with superb print quality A matrix printer, on the other hand, uses pins to print a pattern of dots on paper The characters are generated by selecting the appropriate combinations of pins in a rectangle of rows by columns or columns Each pin is equipped with a coil, which, when energized, throws the pin against the ribbon, printing a dot on the paper For each character, seven or nine lines of dots have to be printed; however, the inertia is minimal, so fast operation is possible The general advantages of using matrix printers are relative low cost, high speed, and quiet operation The main disadvantage is the relatively poor quality of printing, which is sufficiently good for the eye, but not for reproduction or for business letters 27 English for Information Technology Finally, the printing mechanism in line printer is completely different from matrix printers In the line printer, the character set to be printed is on a cylinder where each segment has the full set of characters in raised form around its edge All segments are aligned with one another, that is, all the “As”, for example, are in line Whenever the printer is in print mode, the cylinder is rotating and each character in the set passes by the line to be printed as one complete revolution of the cylinder is made The printer times the movement of a print hammer so that the character on the cylinder is brought into contact with the ribbon and paper One complete line of characters is printed during one revolution of the cylinder.It is interesting to note that all the “As” used in the line are printed first, then all the “ Bs” , and so on until finally all the letters that make up the words have been printed and the line is complete Whereas 200 to 600 lines per minute maximum are produced by the other printers, a line printer will operate up to 3,000 inches per minute There are several types of non-impact printers called thermal and electrosensitive printers ( electrostatic printers) These printers use a special chemically treated paper and expose the characters onto it by some means such as laser The characters are then fixed onto the paper by heating it Because the printing element is simple and has no moving parts, these printers are inexpensive and silent These newer devices are also much faster and allow any character set to be used In addition to drawing lines and shading, light can be flashed through a translucent slide to expose a drawing onto the paper Very fast non-impact printers are capable of rates up to 13,360 lines per minute In the largest computer installations, where cost is no longer a consideration, non-impact printers are used for very high speed An ink jet printer operates by projecting small ink droplets and deflecting them electrostatically Speeds of 40,000 lines per minutes may be achieved In the laser writer, the paper is charged electrostatically and attracts dry ink powder, as in a Xerox machine The pattern is then baked in the paper Many lines are printed simultaneously, and speeds of 20,000 lines per minute can be attained Multiple copies of output are often required, and can be produced either by printing the report several times or by using multipart paper, which consists of layers of paper seperated by carbon sheets However, non-impact printers can not use such multipart paper Microfilm is often used as alternative to the printer The output is “ printed” on microfilm rather than paper, which, in addition to being faster, also condenses large stacks of paper down into small amounts of microfilm with no special programming The drawback of computer output microfilm (COM) is that it takes a special device to print the microfilm and a special viewer to read it Main idea Which statement best express the main idea of the text? Why did you eliminate the other choices? 28 English for Information Technology Line printers are the most superior of the impact printers because they are fastest Basically, there are two types of printers: impact and non-impact Microfilm is replacing the printer because it is a faster way of storing information Understanding passage Decide whether the following statements are true or false (T/ F) by referring to the information in the text Then make necessary changes so that the false statements become true A printer output of the data- processing operations is valuable because it provides a permanent record of the results Chain and train printers give a better quality printing than drum printers Drum printers move sideways across the page The matrix printer is excellent for business letters because the print is very clear Line printers are much faster than other impact printers Line printers print one complete word at a time Thermal and electrostatic printers are capable of shading, whereas impact printers are not Where speed is required, line printers are used Laser writers are capable of printing more than one line at a time 10 Computer microfilm of printed using the regular printer Translate the text into Vietnamese 29 English for Information Technology UNIT STORAGE DEVICES Task1 Study these rules for CD-ROM and floppy disk care Tick ( ) things to and cross (x) things not to ……… Hold a CD-ROM by the edges ……… Keep the optical / silver side of a CD-ROM clean …… Smoke when you use CD-ROM drive …… Put sloppy disks near a magnet …… Keep disks away from the sun and excessive heat …… Write the contents on the label on your floppy disk …… Put extra labels on floppy disks …… Remove by force a disk stuck in the drive …… Remove a disk when the drive light is on Task Read the text below A Most computers can use floppy disks Floppies conform to a standard and you can use them to carry data from one place to another They are also very cheap, but they are slow and have limited capacity B All most desktop computers have hard disks They are fast and an store much greater amounts of data than floppies, but they are fixed inside the computer and you cannot use them to transfer data C You can move data from place to place using removable hard disks and also have high capacities, but they are relative expensive They not all conform to one standard and they are not very common D CD-ROM disks are very common and conform to a standard They are removable and can hold large amounts of data They are also cheap to make However, they are usually read-only You cannot change the information on them They are also slow compared to hard disks E Magneto-optical disks are like CD-ROMs, but you can write data on them They are removable, have large capacities, and last for a long time, but they are expensive and not all conform to one standard For this reason they are not very common F Magnetic tape is cheap medium You can use it to store very large amounts of data, but it does not allow random access Every time you read or write a piece of data, you start at the beginning of the tape Tape drives are slow Therefore, it is only suitable for doing backups Workgroup Read the text again and complete your selections of the table Medium Floppy disk Fixed hard disk Advantages 30 Disadvantages English for Information Technology Removable hard disk CD-ROM disk Magneto-optical disk Magnetic tape Now exchange information with the other students in your group to complete all the sections of the table Ask questions like these What are the advantages of floppy disks? What are the disadvantages of magnetic tape? Do CD-ROMs conform to a standard? Language work: Linking words Study examples Magnetic tape is cheap, but it is very slow because tape drives are slow, so we use it only for backups We use but to show a contrast, because to show that the next idea is a reason, and so to show a result Other words and phrases used in this way are: however (contrast), therefore (result), and for this reason (result) Magnetic tape is cheap However, it is slow to use Magnetic tape is slow Therefore, we use it only for backups Magnetic tape is slow For this reason, we use it only for backups Task Fill in the gaps in this summary of storage devices using the correct words in the box But however because so Therefore for this reason Floppies are very cheap, 1………………… they are slow and have a limited capacity Hard disks are fast and can store large amounts of data 2…………………… they are fixed inside the computer, …………………… you cannot use them to transfer data You can transfer data with remove hard disks, ……………… they are very expensive CDROM disks can hold quite large amounts of data, …………………… , they are usually read-only ……………… you cannot change the information on them Magnetopical disks are like CD-ROMs …………… you can write data on to them They are removable and have large capacities, 8……………………… they are expensive and not conform to a standard 9……………… they are not very common Magnetic tape is cheap and has a large capacity, 10 …………………… It does not allow random access and drives are slow 11 ………… it is only suitable for backups Task Study this description of one method of backing up your files 31 English for Information Technology Work in pairs to complete the table and answer the questions Establishing a comprehensive backup regime Buy 10 tapes and label them Monday, Tuesday, Wednesday, Thursday, Friday1, Friday 2, Friday 3, Month1, Month 2, Month For the first week, back up everything on each day to the appropriately named tape, and on Friday, use Friday In week 2, the same but use Friday 2, and in week use Friday In week 4, exactly the same, but on Friday use Month Do the same for the next two months, but on the last Friday of each month, use Month 2andMonth Then start the whole cycle again With ten tapes, at any point in time you have full daily backups for the last week, full weekly backups for the last month, and full monthly backups for the last three months Fill in the gaps in this table Tape Label Monday Tape 10 Wednesday Label Friday2 Month Which tape you use on these day? Friday, Week 2 Friday, Week Thursday, Week Monday, Week Friday, Week Reading Comprehension TYPES OF MEMORY As mentioned previously, one of the most important characteristics of a computer is its capability of storing information in its memory long enough to process it Not all computer have the same type of memory In this section, three types of memory will be discussed: core memory, semiconductor memory ( or chip), and bubble memory The memory of the first computers was made up of a kind of grid of fine vertical and horizontal wires At each intersection where the wires crossed, there was a small ferrite ring called a core (hence the name “core memory” which was capable of being either magnetized or demagnetized Every intersection had its unique address: consequently, when an electrical current was passed through the wires, the magnetized as well as the unmagnetized cores were identified by their 32 English for Information Technology respective addresses Each core represented a binary digit of either or 1, depending on its state Early computers had a capacity of around 80,000 bits; whereas now, it is not surprising to hear about computers with a memory capacity of millions of bits This has been made possible by the advent of transistors and by the advances in the manufacture of miniaturized circuitry As the result, mainframes have been reduced in both size and cost Throughout the 1950s, 1960s and up to the mid 1970s, core memory dominated the market In the 1970s, there was a further development which revolutionized the computer field This was the ability to etch thousands of integrated circuits onto a tiny piece (chip) of silicon, which is a non-metallic element with semiconductor characteristics Chips have thousands of identical circuits, each one capable of storing one bit Because of the very small size of the chip, and consequently of the circuits etched on it, electrical signals not have to travel far, hence, they are transmitted faster Moreover, the size of the components containing the circuitry can be considerably reduced, a step which has led to the introduction of both minis and micros As a result, computers have become smaller, faster, and cheaper There is one problem with semiconductor memory, however; when power is removed, information in the memory is lost unlike core memory, which is capable of retaining information during a power failure Another development in the field of computer memories is bubble memory The concept which consists of creating a thin film of metallic alloys over memory board When this film is magnetized, it produces magnetic bubbles, the presence, or absence of which represents one bit of information These bubbles are extremely tiny, about 0.1micrometer in diameter Therefore, a magnetic bubble memory can store information at a greater density than existing memories, which makes it suitable for micros.Bubble memories are not expensive, consume little power, are small in size, and are highly reliable There is probably a lot more to learn about them, and research in this field continues Comprehension Main idea Which statement not express the main idea of the text? Core memory was the first type of computer memory developed There are at least three kinds of memory used in computers Bubble memory is the largest development in computer memory Understanding passage Decide whether the following statements are true or false (T/ F) by referring to the information in the text Then make necessary changes so that the false statements become true The most important function of a computer is to hold information in its memory in order to process it 33 English for Information Technology Minicomputers, microcomputers, and mainframes all have the same kinds of memory Semiconductor memory was developed before core memory and after bubble memory Core memory uses small metal rings which can be magnetized or unmagnetized The state of the core can be represented by either or Early computer memories had less storage capacity than newer ones A transistor and a chip are the same kind of device The development of chips made it possible for minicomputers and microcomputers to be invented Bubble memory is smaller than a chip 10 Bubble memory doesn’t have very many advantages DATA PROCESSING AND DATABASE The data processing is performed by a computer, programmers and operators The functions of the computer are to perform operations as they are programmed to, and to make the results of these operations accessible to computer users The functions of programmers are to prepare, test, and document computer programs We may say, the computer capabilities are limited only to the imagination of the programmers only The functions of computer operators are to feed data into the computer for being processed An approach used by operators in data processing is structuring and organizing the data so as to make them useful to everyone who wants to use them This process is called database management Answer the questions Who is the data processing performed by? What are the functions of computers? What are the functions of computer operators? Give the definition of the concept” database management” Translate the paragraph into Vietnamese? 34 English for Information Technology UNIT NETWORKS Task1 Study this example of a local area network (LAN) Answer these questions Who are the users? What kind of hardware is used? What the doctors use it for? What the receptionists use it for? What does the practice manager use it for Task work in pairs List some places where you might find a local area network Task Read the text and then answer the questions WHAT IS A NETWORK? A network is simply two or more computers linked together It allows users to share not only data files and software applications, but also hardware like printers and other computer resources such as fax Most networks link computers within limited area – within a department, an office, or a building These are called Local Area Networks, or LANs But networks can link computers across the world, so you can share information 35 English for Information Technology with someone on the other side of the world as easily as sharing with a person at the next desk When networks are linked together this way, they are called Wide Area Networks, or WANs Net works increase productivity by allowing workers to share information easily without printing, copying, telephoning, or posting They also save money by sharing peripherals such as printers Questions: What is network? What are its hardware components What is the difference between a local area network and a wide area network? What advantages you think networks have? Language work: Predicting consequences Example: The cable fails The whole network will fail (action) (consequence) If the cable fails, the whole network will fail If you don’t use the right password, you won’t get access to the network Note: The action is in the Present Simple, and the consequence in the Simple future Task Link each action (1 – 10 ) with a suitable consequence ( a – j ) Example: If you place a floppy disk near a magnet, you will destroy the data you place a floppy disk near a magnet a the cursor moves to the left You press Print Screen b The computer hangs you input the correct password c it is not lost when you switch off you add memory to a computer d you damage the drive you move the mouse to the left e you copy the screen you store data in RAM f you have access to the network you use a faster modem g you destroy the data there is a memory fault h it runs faster you press the arrow key i your phone bill are lower 10 you move a CD-ROM drive with the j the cursor moves across disk in place Task A Answer the questions: What is a LAN? What is a WAN? B Before reading the text below, match these words and phrases with their definitions 36 English for Information Technology protocol bulletin board user interface make a query parse synchronous a analyze the syntax of a string of input symbols b teleconferencing system allowing users to read messages left by other users c agreement governing the procedures used to exchange information between co-operating computers d means of communication between a human user and a computer system e taking place at exactly the same time as something else f request a search C Read quickly through the text below, and then match each paragraph with the appropriate summary Network uses, past and present How distributed systems work Networks and the future What networks are and how they operate The growth of networks, past and present Reading Comprehension COMPUTER NET WORKS Computer networks link computers by communication lines and software protocols, allowing data to be exchanged rapidly and reliably Traditionally, networks have been split between wide area networks ( WANs) and local area networks (LANs ) A WAN is a network connected over long-distance telephone lines, and a LAN is localized network usually in one building or a group of buildings close together The distinction, however, is becoming blurred It is now possible to connect up LANs remotely over telephone links so that they look as though they are a single LAN Originally, networks were used to provide terminal access to another computer and to transfer files between computers Today networks carry email, provide access to public debased and bulletin board, and are beginning to be used for distributed systems Networks also allow users in one locality to share expensive resources, such as printers and disk-systems Distributed computer systems are built using networked computers that cooperate to perform tasks In this environment each part of the networked system does what it is best at The high – quality bit – mapped graphics screen of a personal computer of workstation provides a good user interface The mainframe, on the other hand, can handle large numbers of queries and return the results to the users In a distributed environment, a user might use his PC to make a query against a central database The PC passes the query, written in a special language (e.g Structured Query Language – SQL ) to the mainframe, which then passes the query, returning to the user only the data requested The 37 English for Information Technology user might the use his PC to draw graphs based on the data By passing back to the user’s PC only the specific information requested, network traffic is reduced If the whole file were transmitted, the PC would then have to perform the query itself, reducing the efficiency of both network and PC In the 1980s, at least 100,000 LANs were set up in laboratories and offices around the world During the early part of this decade, synchronous orbit satellites lowered the price of long-distance telephone calls enabling computer data and television signals to be distributed more cheaply around the world Since then, fiber-optic cable has been installed on a large scale, enabling vast amounts of data to be transmitted at a very high speed using light signals The impact of fiber optics will be considerably to reduce the price of network access Global communication and computer networks will become more and more a part of professional and personalizes as the prices of microcomputers and network access drops At the same time, distributed computer networks should improve our work environments and technical abilities TERMINALS As central computers became faster and more powerful, it was possible to establish many remote display stations from which operators could all use the same computer to display information and enter data Later, even the small machines were equipped with a fairly large display screen and keyboard oriented towards use by a person with limited training, rather than by a highly skilled computer operator For many interactions with computers a permanent record is unnecessary; therefore, output that is scanned once and then thrown away produces a lot of wasted papre To solve this problem cathode ray tube (CRT) terminal can be used In addition to eliminating paper waste, these terminals are completely silent and frequently much faster than hard-copy terminals Because of their speed and quietness, CRT terminals are very useful interactive devices for use in offices and in other areas The electronic circuitry used in them is very much the same as that in the familiar TV (video) set These display terminals are diverse and colourful The original video output was single colour ( black and white) upper-case letters, but in more highly developed devices, lower-case letters can be displayed, and some give options of blinking and dual-density characters Certain screens can produce “ negative” (dark) characters on a bright background or even make each character a different colour, if so desired The later is an important feature in order to catch someone’s attention when a value is abnormal 38 English for Information Technology More sophisticated screen can generate continuous lines for graphic displays The simplest of these are monochromatic and may have: strictly limited graphic applications For example, they may use special characters strung together in order to form lines that look continuous, or they may be restricted regarding the number and the shape of curves that can be drawn at once Multicolour pictorial graphics are extremely useful in emphasizing contrast, and have been used with good result in nuclear medicine, where differences in intensity would be too subtle if shades or only one colour were used The full power of visual display terminals may soon be realized Already dynamic ( motion) graphics output devices that display simple changing scenes have been developed for flight trainers and computer-generated movies These devices could have an important impact on the use of computer-assisted instructions (CAI) techniques in school and colleges Besides screens, a wide variety of devices called plotters and are used to produce permanent copies of graphics output The first plotter developed used a pen that moved back and forth across the rotating drum to which paper was attached These devices produced results which were both quite accurate and reasonably fast Other plotters featuring a moving pen in two dimensions are relatively slow, because not only are they mechanical devices, buy also most can produce only one continuously line at a time However, the modem electrostatic plotter, an extension of the previously mentioned electrostatic printer, can obtain slightly less artistic results in seconds because it doesn’t depend on a moving pen This is because it electronically generates patterns of dots in a line across the page to make up a picture Graphic output may be an effective alternative to high-speed hard-copy output where graphs are more useful than columns of numbers for showing results Most of the time, a graph is not only better than columns and pages of printed numbers, but also has the advantages of being quicker to produce and easier to understand and file.Pen plotters have been used a great deal in scientific research, where results are often expressed in terms of graphs In recent years, new output devices have been developed to bridge the gaps between the various devices just described For instance, terminals with both video screen and hard-copy output are now available These devices don’t waste paper, since hard copy is produced only when a permanent record is needed Terminals of this nature are used in applications where relevant personal data is needed which can be corrected or edited on a screen before a 39 English for Information Technology hard copy is made University registration or patient registration are two areas where these devices save time and money, because a new hard copy need be produced only if something has changed from the previous registration or visit Finally,there are electrostatic printer-plotters available which produce both print and graphic display with equal facility It is possible with these devices to change the style and size of the letters at the users’wish and to have graphs and displays interspersed between the printed lines It is therefore very clear that in modem times, the converging technologies of printers, plotters, and graphic displays have resulted in the creation of a few hybrid devices capable of doing many things Main idea Which statement best express the main idea of the text? Why did you eliminate the other choices? CRT terminals are interactive peripheral devices which allow users access to the computer even from remote stations Modem terminals have numerous features which can be of use in computerassisted instruction Some modem terminals are equipped with video screen and hard copy output Understanding passage Decide whether the following statements are true or false (T/ F) by referring to the information in the text Then make necessary changes so that the false statements become true The development of CRT terminals helped reduce the problem of wasted paper Blinking is one of the features which display terminals are incapable of Multicolour graphs are more useful in modem medicine than monochromatic graphs Plotters can move in various directions, but the majority produce one continuous lines at a time All plotters depend on a moving pen Terminals with video screens and hard copy output are useful for checking student records Terminals are considered peripheral devices but plotters are not Both interactive terminals and plotters have to be on-line at all times 40 English for Information Technology On modem terminals, it is possible to display both upper and lower case letter 10 Dynamic graphics were first developed for computer-assisted instruction (CAI) 41 ... the medium used in inputting information) reads the information into the computer For outputting information, two common devices used are a printer which prints the new information on paper, or... English for Information Technology UNIT INPUT DEVICES Task Match these pictures of input devices with their names - joystick - barcode reader - graphics tablet - digital camera - trackerball - scanner... many different devices used for feeding information into a computer There aren’t as many different types of devices used for giving results as there are for accepting information Computers can make