Equivalence: the following words or constructions are used to show that things or people are similar in some way.

Examples:

1 Here, the term 'processor' is equivalent to the central processing unit.

2 Laptops are as powerful as microcomputers.

3 Some companies have as many computers as employees.

4 Some companies use both disks and conventional filing systems for storing data.

5 A computer virus is like a virus in the human body. It can do a lot of damage.

6 Many word-processing programs are similar in that thother,re certain common functions.

2 Non-equivalence: the following words and constructions are used to compare or contrast things or people that are separate from each other.

Examples:

1 A mainframe is larger and more expensive than a microcomputer.

2 Learning to use a computer is not as difficult as learning to program.

3 A fax board costs less tha(superlative),e.

4 Unlike factory-sealed software, pirated versions may contain viruses.

5 Desktop publishing is the same as electronic publishing.

6 You can save money with a network because you will need fewer printers.

3 The highest degree: the following words and constructions are used to compare one member of a group with the whole group (superlative).

the ...-est the most ... the least ...

Examples:

1 This is the most popular package on the market today.

2 BASIC is probably the least difficult programming language to learn.

3 The best programs are those adapted specifically to your own needs.

4 Parallel increase: the following words and constructions are used to show parallel increase (two comparatives).

the ...-er, the more ... the more ..., the ...-er the ...-er, the less ...

Examples:

1 The more memory your computer has, the more datait can store.

2 The bigger your computer system, the less timeyou spend waiting.

3 The more training you give to your employees, the betterthey will perform.

8They tend to judge all other online services based on this first service — often preventing themselves from seeing the advantages of a specific service. (Unit 3)

9Each offers one or more products or features that either do not exist elsewhere or are superior to the same features on other services. (Unit 3)

10Judge it based on what it offers and how it meets your needs —not in comparison to what you're used to using. (Unit 3)

`There! That should make life easier!'

Start-up

Try to answer these questions.

1What is a LAN?

2What is a WAN?

3What is a distributed system?

the text opposite, match these words and phrases with their

aanalyse the syntax of a string of input symbols

ba teleconferencing system allowing users to read messages left by other users

cagreement governing the procedures used to exchange information between co-operating computers

dmeans of communication between a human user and a computer system

etaking place at exactly the same time as something else

frequest a search

Read quickly through the text below, 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 n The growth of networks, past and present

Computer networks

omputer networks link computers by communication lines and

software protocols, allowing data

5 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

io network connected over long-distance telephone lines, and a LAN is a localized network usually in one building or a group of buildings close together. The

15 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.

20 Originally, networks were used
to provide terminal access to another computer and to transfer files between computers. Today, networks carry e-mail, provide

25 access to public databases and bulletin boards, and are

beginning to be used for distributed systems. Networks also allow users in one locality to

30 share expensive resources, such
as printers and disk-systems.

Distributed computer systems are built using networked computers that co-operate to

35 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

40 personal computer or workstation
provides a good user interface.

The mainframe, on the other hand, can handle large numbers of queries and return the results

45 to the users. In a distributed environment, a user might use his

PC to make a query against a

Computer networks link computers locally or by external communication lines and software allowing data to be exchanged rapidly and

reliably. The ² between local area and wide area networks is,
however, becoming unclear. Networks are being used to perform increasingly diverse tasks, such as carrying e-mail, providing access to public databases,

and for ³ . Networks also allow users in one locality to share
resources.

Distributed systems use networked computers. PCs or ^{4 _}

provide the user . Mainframes process ⁶

and return the results to the users. A user at his PC might make a query against a central database. The PC passes the query, written in a special language, to the mainframe, which then^' the query,
returning to the user only the data requested. This allows both the network and the individual PC to operate efficiently.

In the 1980s, at least 100,000 ⁸ were set up world-wide. As

orbit satellites have lowered the price of long-distance telephone calls, data can be transmitted more cheaply. In addition,

10 cable has been installed on a large scale, enabling vast
amounts of data to be transmitted at a very high speed using light signals. This will considerably reduce the price of network access, making global networks more and more a part of our professional and personal lives. Networks should

also improve our work^!' and technical abilities.

distinction fibre-optic protocols synchronous

distributed systems LANs queries workstations

environments parses screen handling

Writing

Task 7Translate the third paragraph, beginning 'Distributed computer systems...' into

your own language.

Listening

Listen to this extract from the radio programme Computerworks about LANs. Indicate whether the following items are mentioned ( ✓ ) or not mentioned (x).

1LANs are equally useful to large and small companies.

2___ Companies can install their own LANs, provided they are not too big.

3____ Whether or not a company builds a 'do-it-yourself' LAN depends on the

amount of space available for the installation.

4It is sometimes still possible to install part of a LAN if you don't have the

computer knowledge or time to do the whole job yourself.

5_____ You need at least three years' computer maintenance experience before

you should attempt to install a LAN.

6____ In order to install your own LAN, you need to be used to opening up

computers, adding and removing expansion boards, and consulting computer documentation.

7_____ When installing your own LAN you should expect to have to repeat the

same process several times.

8____ The installation process often causes computers to break down.

might want to ⁶ doing it yourself.

Installing a LAN involves running cable to several^' . This may

require you to install junction boxes in walls, do the wiring, and maybe install electrical as well. If you aren't ⁹ with these skills,

and if you aren't a ^1° _ electrician, you will need to hire someone for
this part, at least. Of course, if you're installing your LAN in one room, then you might not need to hire ¹¹

Now listen again to the last part of the recording. Check to see whether your answers match those used by the speaker.

Network configurations

Reading

1 Star

In the star configuration, the central computer performs all processing and control functions. All access devices are linked directly to the central computer. The star configuration has two major limitations. First of all, the remote devices are unable to communicate directly. Instead, they must communicate via the central computer only. Secondly, the star network is very susceptible to failure, either in the central computer or the transmission links.

Switched

The central switch, which could be a telephone exchange, is used to connect different devices on the network directly. Once the link is established, the two devices communicate as though they were directly linked without interference from any other device. At the end of the session, the connection is closed, freeing capacity for other users and allowing access to other devices. Multiple switches can be used to create alternative transmission routes.

Ring

Each device is attached to a network shaped as a continuous loop. Data proceeds in only one direction and at a constant speed round the loop. Devices may send information only when they are in control of the 'token'. The token is a package of data which indicates which device has control. The receiving device picks up the token, then clears it for another's use once it has received the message. Only one device may send data at any given moment,

and each device must be working for the network to function.

Bus/Ethernet

A bus network consists of one piece of cable terminated at each end to which all devices are connected. In a bus-based network, each device is able to broadcast a message when it has detected silence for a fixed period of time. All devices receive the broadcast and determine from the content of the message whether it was intended for them. The only problem occurs when two devices try to send at the same time. When a sending device detects another's transmission, it aborts its own.

Task 11These are answers to questions about the texts. Write the questions.

1To connect different devices on the network directly.

2No, it goes in only one direction round the loop.

3No, only one device may send data at any given moment.

4From the content of the message.

5It cancels its own transmission.

Task 12Which of the network configurations on page 71 does this flowchart refer to?

Task 13The columns below describe characteristics of the bus and ring configurations.

Which column refers to which configuration? How did you decide?

A

varied time response calculable time response

easy expansion difficult reconfiguration

fault-tolerant fault-intolerant

simple more complex

Speaking

Student A: You are a customer interested in the Netplan Eazy Kit. Before deciding whether to buy it, ask questions to find out:

1 what you need in order to use the Netplan Eazy Kit.

2 the total number of PCs you can run on it.

3 the cost of adding additional PCs.

4 how difficult it is to install.

5 what software it runs.

6 the other features offered.

Student B: You represent the makers of the Netplan Eazy Kit. Make notes about the features of the product. Answer any questions and try to encourage the customer to buy it.

	Netplan Eazy Kit from as little as £215
	This is not the only way to share software. If your idea of sharing software is looking over a colleague's shoulder, then Netplan may have the ideal solution. To benefit from a network you only need two PCs. The Netplan Eazy Kit costs just £215 and gives you all the hardware, software, and cabling you need to link two PCs. And for £100 per PC you can extend the network to up to six users. With Netplan Eazy even the smallest business can save time, money, and effort.
	Extra efficiency The Netplan Eazy Kit allows PCs to share the same data and software without having to copy and transfer disks. So whether you're dealing with customer enquiries or updating accounts, you can do it from the same machine. You can even send messages from one PC to another by e-mail. Netplan Eazy will also save you money on expensive resources like printers.	It's so Eazy If you can use a screwdriver, you can install Netplan Eazy yourself. That's all it takes. And once installed, it runs on all popular software. We also offer our customers unlimited access to our Freephone Helpline as part of the package. So why wait? Contact your nearest Netplan dealer today. Details are on the back cover of this magazine.

Word-play

Task 15Solve the crossword puzzle using the clues below.

Across

1The means of communication between a human and a computer. (4,9)

5To load software on to a computer, ready for use. (7)

7To transmit a message to all nodes on a network. (9)

9and 3down Usually found in one building or a group of buildings close together. ( 5 ,4, 7)

10This kind of network often uses a telephone exchange to connect different devices directly. (8)

Down

2Taking place at exactly the same time as something else. (11)

3See 9across.

4An_____ board may be inserted into a computer to give it added features. (9)

6The opposite of 9across and 3down. (3)

8The network configuration in which all devices are linked through the central computer. (4)

Language focus

Time sequence

In activities such as scheduling, doing routine activities, and conducting and describing experiments, it is important to recognize the sequence of events. As we know, events do not simply occur in isolation, they occur either before, during, or after other events. This time sequence may be chronological, logical, or causal. The following tables show examples of time relaters.

1 Before given time-references:

Time relaters

Examples:

1 The memory storage capacity of earliercomputers was not as large as those of today.

2 When the first digital computer was developed, the first analog computer had already been in use for some time.

3 Up to now, voice recognition technology has not been developed for mass marketing.

2 Simultaneous with given time-references:

Time relaters

at present

at this point now/then

today

for the time being at the moment

at that time

meantime meanwhile

in the meantime when

at the same time

Examples:

1 At that time many new computer programs were being developed for use in businesses.

2 Computers may soon take over many daily tasks, but in the meantime ordinary people must continue to do them themselves.

3 Computer magazines keep us informed about contemporary issues in the computing world.

1 Since the development of the chip, computers have become cheaper and more compact.

2 You should have a good idea of the various applications of computer software by the time you finish reading this book.

3 Although initial versions of word-processing programs were not very complex, later versions were much more sophisticated.

Sample paragraph:

Computers, as we know them today, have not been around for a long time. It was not until the mid-1940s that the first working digital computer was completed. But since then, computers have evolved tremendously. Vacuum tubes were used in the first-generation computers only to be replaced by transistors in the second-generation computers at the beginning of the early1960s. By the end of the 1960s, transistors themselves were replaced by tiny integrated circuit boards and, consequently, a new generation of computers was on the market. Fourth-generation computers are now produced with circuits that are much smaller than before and can fit on a single chip. Even now, new technologies are being developed to make even better machines.

Read the following sentences which come from previous units. Underline the time relaters and indicate whether they refer to before, during, or after the given time reference. The first one has been done for you.

1after Since then, over seventy million PCs made by IBM and other

manufacturers have been sold. (Unit 1)

2 Over this period, PCs have become commodity items. Since IBM

made the design non-proprietary, anyone can make them. (Unit 1)

3 _ Ten years later, in 1991, IBM were making PCs with 16Mb of

memory, expandable to 64Mb, running with a processor speed of 33MHz.

(Unit 1)

4 Large companies are considering running major applications on PCs, something which, ten years ago, no one would have believed possible of a PC. (Unit 1)

5 ____________ When the computer finds the closest match, it encodes the

character in memory and displays it on the screen as if it has been typed.

(Unit 2)

6 Enter the clipboard computer, a technology that has been in development for the last 20 years but took hold in the mass market only this year. (Unit 2)

7 Eventually, we're all going to be interlinked, no matter which

service we use, in what DIALOG's Richard Ream calls a 'network of networks'. (Unit 3)

8 Until then, most of us have to go to more than one service to

find everything we need. (Unit 3)

Start-up

Task 1Try to answer these questions.

1 What is a computer virus?

2How does a virus work?

Reading

Task 2Before reading the text, match the words and definitions listed below.

1a detonator

2an infector

3to boot

4to trigger

5to erase

6pirated

7a shield

8to detect

a a protective device

bto remove all traces of something

c a device used to set off an explosion or other destructive process

d to discover or recognize that something is present

e to set a process in motion

fsomething which transmits a disease or virus

g stolen, obtained without the owner's consent

h to load the operating system into memory

Task 3Now read the text to check your answers to Task 1.

How computer viruses work

computer virus — an unwanted program that has entered your system without you knowing about

5 it— has two parts, which I'll
call the infector and the
detonator. They have two
very different jobs. One of
the features of a computer

10 virus that separates it from other kinds of computer program is that it replicates itself, so that it can spread

(via floppies transported

15 from computer to computer, or networks) to other computers.

After the infector has
copied the virus elsewhere,

20 the detonator performs the virus's main work. Generally, that work is either damaging data on your disks, altering what you see on your

25 computer display, or doing something else that interferes with the normal use of your computer.

Here's an example of a

30 simple virus, the Lehigh virus. The infector portion of Lehigh replicates by attaching a copy of itself to COMMAND.COM (an

35 important part of DOS), enlarging it by about 1000 bytes.

So let's say you put a floppy containing

40 COMMAND.COM into an infected PC at your office —that is, a PC that is running the Lehigh program. The infector portion of Lehigh

45 looks over DOS's shoulder, monitoring all floppy accesses. The first time you tell the infected PC to access your floppy drive, the Lehigh

50 infector notices the copy of
COMMAND.COM on the

floppy and adds a copy of

itself to that file.

Then you take the floppy 105

55 home to your PC and boot

from the floppy. (In this case, you've got to boot from the

floppy in order for the virus

to take effect, since you may

so have many copies of COMMAND.COM on your

hard and floppy disks, but

DOS only uses the COMMAND.COM on the 115
65 boot drive.)

Now the virus has silently

and instantly been installed

in your PC's memory. Every

time you access a hard disk 120

70 subdirectory or a floppy disk containing COMMAND.COM, the virus sees that file and

infects it, in the hope that this particular COMMAND.COM 125

75 will be used on a boot disk on
some computer someday.

Meanwhile, Lehigh keeps a count of infections. Once it

has infected four copies of 130

80 COMMAND.COM, the

detonator is triggered. The detonator in Lehigh is a

simple one. It erases a vital

part of your hard disk, 135

85 making the files on that part

of the disk no longer

accessible. You grumble and set about rebuilding your

work, unaware that Lehigh is 140 90 waiting to infect other unsuspecting computers if

you boot from one of those

four infected floppies.

Don't worry too much 145

95 about viruses. You may

never see one. There are just a few ways to become

infected that you should be

aware of. The sources seem 150

100 to be service people, pirated games, putting floppies in

publicly available PCs

without write-protect tabs, commercial software (rarely), and software distributed over computer bulletin board systems (also quite rarely,

despite media misinformation).

Many viruses have spread through pirated — illegally copied or broken — games. This is easy to avoid. Pay for your games, fair and square.

If you use a shared PC or a PC that has public access, such as one in a college PC lab or a library, be very careful about putting

floppies into that PC's drives without a write-protect tab. Carry a virus-checking

program and scan the PC before letting it write data onto floppies.

Despite the low incidence of actual viruses, it can't hurt to run a virus checking

program now and then. There are actually two kinds of antivirus programs: virus shields, which detect viruses as they are infecting your PC, and virus scanners, which detect viruses once they've infected you.

Viruses are something to worry about, but not a lot. A little common sense and the occasional virus scan will keep you virus-free.

Remember these four points: Viruses can't infect a data or text file.

Before running an antivirus program, be sure to cold-boot from a write-

protected floppy.

Don't boot from floppies except reliable DOS disks or your original production disks.

Stay away from pirated software.

Vocabulary

fair and square (1. 113) — honestly

it can't hurt (1. 126) — it's probably a good idea

Task 5Indicate the line reference where the following ideas are found in the text.

line

1 1. The Lehigh virus must infect four copies of COMMAND. COM before

damage is done to data.

21 _ _Always boot your computer from dependable DOS disks or your original disk.

31. The infector part of a virus must first copy itself somewhere before the

detonator part damages the data on your disks.

41_ Virus scanners discover viruses after the infection and virus shields

discover viruses during the infection process.

Task 6These are answers to questions about the text. Write the questions.

1 Two, one that infects and one that does the damage.

2By interfering in some way with the normal use of the computer.

3After it has infected four copies of COMMAND.COM.

4Every time you access a hard disk subdirectory or a floppy disk containing COMMAND.COM.

5Yes, by using your common sense and by occasionally scanning for them.

Computer security

Security breach blamed on hacker'

Year-old

Hacks into

Bank's database

Computer fraud on the increase

Speaking

Task 9In pairs, try to answer these questions:

1 Who or what is a 'hacker'?

2 How many ways can you think of to make the data in a computer secure?

Listening

Task 10Listen to Steve, a computer technician, and Richard, the office manager at a

language institute, talking about computer security.

As you listen to the conversation, answer the following questions.

1 What is the problem with the computer system at the language institute?

2 What would someone need to connect his/her PC to the office network?

3 What are the disadvantages of security passwords, according to Steve and Richard?

4 How does the 'smart' card work? Is it safe?

5 How much do you think Steve and Richard know about security systems?

Reading

Task 12

The combined threat of viruses y,reakii.g havoc on y ^,ir PC and probing meddlers gaining access to sensitive dai can strike fear into the hearts of even the most mild-mannered PC managers. Relax XTree Company has the ultimate in PC protection. AllSafe teams superior vims prevention with aura^, 0^,11701 and security reporting.

And while most ant-virus produc_^, simply scan or known virus signatures, AitSafe actually looks for the signs of viruses attempting to replicate. Once a virus is spotted, AllSafe isolates it, preventing the virus from infecting your PC. If the virus is known, AllSafe quickly removes it. Even it the virus is unknown, AllSafe studies it and learns its signature immediately, letting you automafically update the virus signature database Then you can use AllSale to scan other disks or

systems right away before

an infection can spread,

without waiting for a new AUSAFE

signature from the

are publisher. So, if you use a,gandalone PC, fear not Its over for the evil virus.

Just as scary as the viruses are those characters that attempt to invade your computer files without authorization. AllSafe's flexible password options let you share or limit acces to as much of your hard disk as you wish. AllSafe keeps out the evil invaders!

When you need a complete solution - protection against both viruses xi(' unauthorized entry - choose AllSafe. And like all XTree Company products, they're easy to install and use. For more information or to find out where you can buy AilSafe, call one of our distributors:

Softsel UK (081) 588-8866 P&P (0706)217-744

Ingram Micro UK (0908)260460 Frontline (0256)27890

XTREE

COMP

qc 01191 LleMS■iteffe, ram

FREE FACTS 091

The flowchart on the following page represents the steps in the process by which AliSafe removes viruses from PCs. Using the information in the advertisement, match each step with the corresponding letter in the flowchart.

1Virus signature database is updated.

2Is virus known?

3AllSafe scans other disks or systems in order to prevent further infection immediately.

4AllSafe searches for indications that viruses are

attempting to copy themselves.

5AllSafe identifies and isolates the virus.

6AllSafe eliminates the known virus.

7AllSafe analyses the virus and learns its signature straight away.

Task 13Find words or phrases in the text which mean:

1wickedness, badness, danger

2hides (while waiting to attack)

3causing a lot of damage

4people who interfere without authorization

5terrify, make very afraid

6combines

7identified, recognized

8frightening

9choices

10attackers

Speaking

Task 14Discuss the following questions:

1What technique does the advertisement use to persuade people to buy the product?

2Do you think the advertisement is successful? Give reasons for your opinion.

3What other techniques could be used to sell this kind of software?

NSA consultant's son is

Computer saboteur

`Worm' came from graduate student

A

court heard today how a Cornell University graduate student,

Robert T. Morris Jr. (25), infected a host of government and educational computer centres with a computer virus, known as a 'worm', which liter­ally brought all computational activi­ty to a halt in over 6,000 installations. Morris, the son of a prominent National Security Agency computer consultant, was sentenced for his offences yesterday. As punishment, he was required to spend no time in prison but, instead, serve three years' probation, contribute 400 hours of community service, and to pay a $10,000 fine along with associated court and probation costs.

1 How serious do you think Robert Morris's crime was?

2Do you think the punishment was

atoo severe?

babout right?

cnot severe enough?

3 Do you know of any similar incidents of computer hacking?

Word-play

The words and phrases below are taken from this unit. In pairs or groups, decide if they have a 'protective' or a 'destructive' meaning as they are used in the unit, then put them under the correct heading.

detonator	infector	erase	pirated
infect	write-protect tab	worm	virus scanner
hacker	password	smart card	shield
signature protective	cipher destructive	keyboard lock	access control

 

How many other ways can you think of to classify them?

Language focus G

Listing

It is important when reading to recognize and understand the relationship in which sentences and groups of sentences combine to present information. This information may be linked by means of a connective word or marker.

Making a list, for example when enumerating, and giving instructions, indicates a cataloguing of what is being said. It is important to note that most enumerations belong to clearly defined sets. The following table is a list of the markers that can be used to show the order in which things are to be said.

1, 2, 3, etc.

one, two, three, etc.

first(ly), second(ly), third place

another, next, then

furthermore, afterwards, moreover

lastly/finally

to begin/start with, and to conclude

first and foremost} mark the beginning

first and most important(ly) of a descending order

above all mark the end of

last but not least an ascending order

There are many ways of showing sequential relationships. Those given in the table above are not the only ones, they are the most common ones used in listing or enumerating. The -ly forms are usually used when listing.

Sample paragraphs:

More and more police departments are now using sophisticated devices to help control the increasing crime rate. Some of these devices are: firstly, a computer terminal inside a police vehicle to answer an officer's questions, secondly, a computer-controlled display unit for displaying fingerprints, and thirdly, educational systems for police officers such as terminals, enabling them to verify changes in laws, rules, and regulations.

The computer memory of many law enforcement systems contains all kinds of information. First and foremost, it has data on stolen items such as cars, licence plates, and property. Second, it has information on missing persons and wanted fugitives. Last but not least, it contains information on political extremist groups and their activities.

Computers have certainly revolutionized police work by providing access to millions of items of information with the least possible delay and speeding up the process of apprehending suspicious-looking characters.

l

Exercise 1Complete the following paragraph about the various steps in the creation of a

database by filling in the blanks with appropriate listing markers.

When you are creating a new database, you must many fields you will need in your database. 2

decide how , you will have to

 

provide up to five items of information about each field. ________ , each

field needs to have a name. ⁴ , the field type has to be defined.
Character, numeric, date, and logical are some common types. ^s

choice to be made is the width of the field. However, some fields, such as date,

	have present default values. The 6 decimal places if the field is numeric. 7 whether the field is to be indexed or not.	step is to set the number of , you will have to indicate

Exercise 2Complete the following paragraph by filling in the blanks with appropriate

listing markers.

Computers can do wonders, but they can waste a lot of money unless careful consideration goes into buying them. Businessmen and women thinking of buying a computer system should ^{I__________________________} admit they know very little

about computers. ² ______________________________________________ , they must realize that the computer sales
people don't always know how their business works.

, it is essential that buyers should get outside advice, not necessarily from consultants but from other executives who have had recent experience in buying a computer system ⁴ they should try to see
systems similar to ones under consideration in operation. Because their operations will have differences that must be accommodated, they should

_______ find out what would be involved in upgrading a system.

__________ important thing to know before buying a computer is the

financial situation of the supplier because computer companies come and go and not all are financially stable. ' , the prospective buyer should
demand that every detail be covered in writing, including hardware and software if they are supplied by different companies. There's nothing wrong with computers themselves, it's how and why they are used that can cause problems.

Computers in the office

	Start-up What aspects of computer technology are illustrated below: Make a list of any other examples used in the office.
Task 1 a

 

Reading

Task 2Read the text opposite. How many of the items you listed in Task 1 are

mentioned:

Visions of Tomorrow

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