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Transcript
МІНІСТЕРСТВО ОСВІТИ І НАУКИ УКРАЇНИ
ТЕЧНІЧНИЙ КОЛЕДЖ
ЛУЦЬКОГО НАЦІОНАЛЬНОГО ТЕХНІЧНОГО УНІВЕРСИТЕТУ
ІНОЗЕМНА МОВА
ЗА ПРОФЕСІЙНИМ СПРЯМУВАННЯМ
МЕТОДИЧНІ РЕКОМЕНДАЦІЇ
ДО виконання
самостійної роботи ДЛЯ СТУДЕНТІВ
ІІІ КУРСУ
СПЕЦІАЛЬНОСТІ 5.05010201 «ОБСЛУГОВУВАННЯ КОМП’ЮТЕРНИХ СИСТЕМ
І МЕРЕЖ»
НАПРЯМ ПІДГОТОВКИ 050102 «КОМП’ЮТЕРНА ІНЖЕНЕРІЯ»
ДЕННОЇ ФОРМИ НАВЧАННЯ
Редакційно-видавничий відділ
Луцького національного технічного університету
Луцьк 2013
1
УДК 811.111:004
ББК 81.432.1+32.973
Семенюк Я. О. Іноземна мова за професійним спрямуванням: методичні рекомендації до
виконання самостійної роботи для студентів ІІІ курсу спеціальності 5.05010201
«ОБСЛУГОВУВАННЯ КОМП’ЮТЕРНИХ СИСТЕМ І МЕРЕЖ», напрямку підготовки
050102 «КОМП’ЮТЕРНА ІНЖЕНЕРІЯ», призначені для денної форми навчання
технічного коледжу Луцького національного технічного університету. – Луцьк, 2013. –
56с.
Укладач:
Я.О. Семенюк.
Рецензент:
Т.А. Крисанова
Відповідальний за випуск:
Т.М. Бондарук
Затверджено науково-методичною радою Луцького НТУ,
протокол №____ від « »__________ 2013 р.
Рекомендовано до друку науково-методичною радою ТК Луцького НТУ,
протокол №____ від « »__________ 2013 р.
Комп’ютерна верстка: Семенюк Я.О.
© Технічний коледж Луцького національного технічного університету, 2013
© Семенюк Я.О.
2
Зміст
Вступ ......................................................................................................................... 4
1. Theme: Future Technique ..................................................................................... 5
2. Theme: Operating System ................................................................................... 13
3. Theme: Computers’ Development History ......................................................... 28
4. Theme: Surf the Net ............................................................................................ 37
5. Theme: Grammar: Direct and Indirect Speech ................................................... 40
6. Theme: The Web ................................................................................................. 44
7. Theme: Grammar: First and Second Conditional ............................................... 46
Література .............................................................................................................. 54
NOTES .................................................................................................................... 55
3
Вступ
Сьогодні освіта розглядається як процес становлення особистості, яка здатна до
саморозвитку, самоосвіти, творчого розв’язання проблем, критичного мислення, ось чому
роль викладача полягає в педагогічній підтримці розвитку студентів.
Самостійна робота являється одним з засобів формування якостей, які притаманні
самоорганізованій та самодисциплінованій особистості, а самоорганізація відображає
свідому роботу студентів над собою з метою самовдосконалення та розвитку
пізнавальних, практичних, емоційних, моральних, вольових здібностей та рис характеру,
являється важливим компонентом в процесі професійної підготовки.
Метою вивчення іноземної мови за професійним спрямуванням на немовних
факультетах є якісна підготовка фахівця у професійній сфері на основі світового досвіду з
використанням тематичного матеріалу, передбаченого програмою даного курсу. Це:
1)систематизація та розширення словникового запасу студентів з професійних тем
комп’ютерного спрямування; 2) навчання студентів правильно вживати вивчені лексичні
одиниці в усному мовленні; 3) розвиток логічного, аналітичного мислення, оволодіння
певною термінологією професійного спрямування та застосовування її на практиці,
розширення світогляду студентів; 4) розвиток уваги, пам’яті, уяви, інтелекту студентів,
мовної здогадки; 5) виховання особистості, яка персонально відповідатиме за свій освітній
та професійний рівень та інтерес до обраної професії. Кінцевою метою навчальнометодичних рекомендацій є підготовка до проміжного контролю у формі тестових
завдань.
Мовний матеріал максимально узгоджений з потребами студентів, в даному
випадку, зі спеціальністю 5.05010201 «ОБСЛУГОВУВАННЯ КОМП’ЮТЕРНИХ
СИСТЕМ І МЕРЕЖ».
Дані навчально-методичні рекомендації побудовані на принципах особистісноорієнтованого навчання, а саме : індивідуалізація, спіралеподібна побудова навчального
матеріалу, постійна самооцінка студента, динаміка просування до успіху, максимальне
наближення навчального матеріалу до життя.
Структурно навчально-методичні рекомендації складаються з 7-ми тем,
які
містять в собі матеріал навчальних семестрів, (денна форма навчання), а також список
використаної літератури.
Навчально-методичні рекомендації призначаються для студентів III курсу,
спеціальності 5.05010201 «ОБСЛУГОВУВАННЯ КОМП’ЮТЕРНИХ СИСТЕ І МЕРЕЖ»,
напрямку підготовки 050102 «КОМП’ЮТЕРНА ІНЖЕНЕРІЯ». Вони можуть також
використовуватись викладачами вищих навчальних закладів нефілологічних
спеціальностей, а також особами, що самостійно вивчають англійську мову.
4
1. Theme: Future Technique
Future Technique
Since the beginning of time technology has helped us out as a human race. From the
invention of the wheel to the Internet, technology has been a great factor on the way our
civilization has grown. With more and more technological advances just around the corner, our
civilization will continue to grow faster and faster than ever before.
People often think that future is all about flying cars, robots and space travelling. Maybe
it will be like that, who knows, but at least until this day the changes haven’t been remarkable.
Companies are all the time investing more money on research and development. This indicates
that companies and government are interested to achieve and find new technological inventions
that would change the markets. All ready one of the computer related inventions, Internet, has
changed the spreading of information globally. Internet is worldwide network of connected
computers. This network enables you to communicate with the rest of the world in different
ways? Has been approximated that the total amount of information globally doubles every 18
months, which indicates that internet, as an important part of media nowadays, affects everyone
of us thought we might not have a possibility to be on-line. The approximated number of people
who are on-line daily is more than 18%? Internet is not only a way to spend time surfing, but it is
also an very good way to make money by transforming products, services and markets. It is an
easy way to reach people when thinking advertising and it is an easy way to people to reach the
information wanted, but the competition between companies in the virtual reality of Internet, is
as hard as in the real world.
Government’s space program also influences and will influence economics of the future.
U.S. government’s NASA (North American Space Association) has done great job exploring
space and research new opportunities in outer space and other planets. The question is how the
new future technology will change the direction of economics and by that our living on Earth or
maybe on some other planet? The world population is growing fast. The room to live on earth
might be a problem in future, and Earth might not be able to feed the upcoming population. This
is one of the reasons why we have to explore the space for new opportunities.
The greatest effect of future technology has is on the productivity. Technological change,
or innovation, is a contributor to the growth of productivity. From the development of plows to
the invention of computers, history shows many examples of technologies that have increased
productivity. New products, new methods of production, new ways of organizing production or
marketing products and new methods of communication can each demonstrate how productivity
increases. This makes people’s everyday life easier and the quality of living is higher. One
example how technological change has changed our living past 10 years have been reusable
products and materials. Recycling and reusable materials have made our quality of living better
by minimizing the production of trash. Also the technological changes in agriculture have
increased productivity of our basic need products.
No one knows what’s going to happen in the future, but the new future technology can at
least give us a direction. Our actions have a great effect how we and the upcoming generations
are going to live on Earth. Putting money now on research and development gives a better
economics base that we can rely on. The biggest change to our economic will have the increased
productivity. By increased productivity our standard of living will be higher and our everyday
life will be easier. May every one of us be there to witness the flying cars and talking robots, so
that we can be proud of our achievements?
5
Computers’ Future
Moore's law predicts that the numbers of discrete elements on a square-inch silicon
integrated circuit will double every two years. While it's not exactly a direct relationship, you can
interpret that to mean that computers will double in processing power every two years. That
means in the years between 2010 and 2050, computer processing power will double 20 times if
Moore's law holds true.
In 2010, IBM introduced the zEnterprise 196 (z196), which boasted a processor capable
of running at 5.2 gigahertz (GHz) -- the fastest commercially available processor at that time.
That means the z196 processor ran at 5.2 billion cycles per second. Every instruction a processor
executes requires a set number of clock ticks. The more clock ticks a processor squeezes into a
second, the more instructions that processor can complete in a given amount of time. That's what
we mean when we say a 5.2-GHz processor is faster than a 3.2-GHz processor -- the 5.2-GHz
microchip is capable of executing more instructions than the 3.2-GHz chip in the same amount
of time.
If 5.2 GHz was the top speed in 2010, what will it be in 2050? Assuming engineers can
find ways to keep up with Moore's law and processor speed actually doubles every 24 months,
by 2050 we'd have a chip capable of running at 5,452,595 gigahertz, or nearly 5.5 pet hertz. It's
hard to imagine what kind of applications we could direct such a machine to tackle. Complex
computational problems, such as building virtual simulations of the human brain, may become a
relatively simple task. Some futurists believe we may even create machines with intelligence far
greater than our own. Perhaps those machines could discover ways to improve processing speeds
even faster than humans can. Before long, you could have a self-improving device pushing the
physical limits of how fast machines can process information.
While this dream of the future is popular among a certain segment of computer scientists
and futurists, other people are more skeptical. Perhaps the human mind is far more complex than
we understand. Thinking may involve more than just electrochemical messages passed between
neurons. Perhaps there's a hormonal element that subtly shapes how we think. If that's the case, it
may be that pure computational horsepower won't be enough to create a machine capable of what
we consider thought.
Setting aside the artificial intelligence debate for a moment, what might futuristic
computers look like? They might actually be invisible. Pervasive computing is a type of
technology that incorporates computers into just about anything you can imagine. Buildings,
highways, vehicles and even the clothing you wear might have built-in computer elements.
Coupled with networking technology, the world of 2050 may be one in which the very
environment around you is part of a massive computing system.
In such a world, your digital life and your real life could overlap seamlessly. We see hints
of this world in today's technology. There are hundreds of smart phone applications that add a
digital layer over our perception of the real world. They might help you navigate around a
strange city or discover a new favorite restaurant tucked away in a corner somewhere. These
applications still require us to activate programs on mobile devices and use those devices as a
lens through which we can see the digital world. In the future, we may be able to accomplish the
same thing using glasses, contact lenses or perhaps even ocular implants. Imagine being able to
look at the world through one of a million different filters, all of which provide different kinds of
information to you instantaneously.
Then again, it's possible that our ingenuity won't be enough to keep up with Moore's law
after a few more microprocessor generations. Perhaps our computers will be more mundane and
functional. But considering the way they've transformed our world over the last 50 years, I'm
willing to bet 2050 will be an exotic, digital era. What do you think?
6
Gadgets from
the Near Future
Keyboard Puzzle
Many PC users often complain that they can
not choose a keyboard to your taste, or complain about
the huge amount of unused buttons. Conceptual Puzzle
Keyboard just for them. This device has a structure of
a puzzle. In other words, you will have the ability to
completely customize the keyboard, some keys to
remove completely, while others moved to a more
convenient location, tilt it for better ergonomics.
Puzzle Keyboard also can interact with mobile devices,
or used as a wired remote management.
Mouse for Innovators
If you are tired of the classic mice, similar to each other and only slightly different in
appearance. Or touchpad for you – is not an option. Then, a new development company, called
Evergreen DN-45545 – this is what you need.
We present you a very strange gadget that is unlike any other device. But this also is a
computer mouse. Forget about the horizontal position arm on a mouse – in this way a mouse you
can not keep. Imagine a better, that keep your hands stick to flight simulation – it will be the
most convincing comparison. As the developers, they have spent a lot of time working on the
ergonomics of the housing Evergreen DN-45545. Developers have this perfect device. As a
result, the mouse received a highly original form, and its surface is almost completely covered
with rubber. Package also includes a cradle under the brush, but it can be removed.
Equipment Evergreen DN-45545 has four function keys. Separately, there is a button
switch sensor resolution and the scroll wheel. The maximum resolution of the sensor is 1600 dpi.
DN-45545 is a manipulator with wire cable 1.5 meters. Device weighs 160 grams and has
dimensions 135h100h82 millimeter.
Smart Highway
Now the roads are not just roads, but be smart. Two Dutch design studios Roosegaarde and
Heijmans developed stunning project a "smart way." It includes a number of interactive
technologies that adapt to traffic conditions and visually show drivers of useful information.
7
The main technological element of the road of the future – the paint. In this respect, the Dutch
ahead over Europe. A few years ago, they got the "nano-paint", which can be controlled with the
remote control – press the blue button and the wall paint, turned blue, red – red, etc.
The concept of the new Dutch road uses a combination of sensors, special inks and high-tech
batteries that collect energy from the wind of passing vehicles.
«Smart Highway» will become reality in 2013.
Road paint «Dynamic Paint» sensitive to temperature. In
normal weather conditions, the paint is transparent, but when the
temperature drops and the road is slippery, the paint shows warning
signs of danger.
«Glow-in-the-Dark Road» – fluorescent dye that absorbs
sunlight during the day and light up to 10 hours at night, which
increases visibility and reduces the need for additional lighting.
Another technique is called "Interactive Light". It uses
sensors to detect an oncoming car, if a car is approaching, the road
begins
to
glow brighter
and fades when the vehicle is removed.
Thus, the road will turn on only when
needed, and will not waste expend energy
reserve. "Smart Highway" was named best
concept.
«Project Glass» by Google
Google
has
demonstrated
a
prototype of the concept points «Project
Glass», which will replace the phone, tablet
and GPS-navigator. According to employees
of the company, Google goggles will be
available in late 2012. One lucky man who has
tried the concept of points «Project Glass»,
said: "These technologies have allowed to
come into our lives. In order to take a picture, I
do not need flattery in his pocket for phone
and just press the button at the top of the
points, that’s all. "
Sony PSP 2 with a Transparent
OLED-display
A year ago, Sony has released a portable console PS
Vita. It a branded gaming gadget second generation
with a productive processor and a bunch of ways to
control gameplay. PS Vita sales were not as serious as
we would like, but the device has found its place in the
market and feels quite decent. What will happen when
the time comes to make another big step forward?
8
This question was answered by of the designer Jung Ou Yang. He introduced the concept of the
portable console Sony PSP 2. The most notable advantage of the toys is transparent 5-inch
OLED-display. The era of these screens is not yet come, but now is the time of the revolution. It
would be possible to begin a large-scale attack and with the portable consoles. On each side of
the display has the traditional controls. Make them transparent obviously is no need.
Other specifications Sony PSP 2 look as dignified. There is a full set of wireless protocols
including Bluetooth, Wi-Fi and 3G, the main and front camera as well as a more powerful
processor than the 4-core chip in the real PS Vita. Maybe a couple of years Sony could well
produce something like that in reality.
Folding Tablet
Wallet – a unique folding device that
can function as a phone, tablet and camera.
Due to its design the gadget easily fits in
your pocket. Wallet is made up of three
parts, each
with
stocked a
display.
Fold the
device
can be
on the basis of a screen. The case is made
of durable innovative material Technogel.
The device is equipped with a camera with
a resolution of 12.1 megapixels and video
recording HD 1080p, has a headphone
jack and a micro-USB type B, through which you can connect to virtually any peripheral
components (mouse, keyboard, printer, even a TV).
Unusual Concept LG Hi-Fi
Unusual concept is a real dream of
music lovers: it can be used as the phone,
and as stereo. Turn the device to the
headphones can one movement hand. MP3
player, as and the drive is built into the
represented gadget. In the prototype use the
touch screen that takes up the entire front
panel when folded. True, on images no
microphone, but if LG Hi-Fi sometime will
see the light, this and other minor disadvantages, of course, will be eliminated.
Smartphone with Perfect Ergonomics
Mobile phones with touch screens have taught us to look at the interaction with the
gadgets a completely new way. The touch interface allows you manage graphics directly on
9
screen mobile. But is it comfortable and stayed there still potential for growth? These questions
try answer Korean designer Wauseon Such to the concept phone Another World.
A distinctive feature of the mobile phone Another World is that it is entirely covered a touch
screen. According to the author, this is the best way to optimize the multi-touch interface, the
user is not required to make any unnecessary movements to perform the required actions, virtual
buttons can appear at any point of the phone.
On the lower half of the front panel of Another World posted additional control element,
which is also at the center is a small touch screen. With this solution, you will never miss all the
most important thing. It is worth noting the original mode of performance interface, this is not
the traditional icons or widgets, straight lines extending radically from a central element. It is a
pity that in the foreseeable future, the market does not appear anything like this.
Exercise1
Match the following headings to their appropriate paragraphs
a) Home Computers
b) From Tubes to Tablets
c) Tablets
d) Laptops, Netbooks and Ultrabooks
e) In 2020 we can wear Sony Computers on our Wrists
………………………………………………………………………………………...……………
Recent innovations such as the iPod provide an exciting glimpse into the future of
computers. Before looking forward toward future computer trends, let's take a quick look back to
gain a better appreciation of the evolution thus far. Do you remember when the first primitive
computing
machines
occupied
entire
buildings? The massive machines from the
mid-20th century consisted of row upon row
of vacuum tubes and wires. You had to use
stacks of punch cards to program these beasts.
Today's computers operate using transistors,
wires and electricity. Future computers might
use atoms, fibers and light. Personally, I don't
give a byte what makes it tick, as long as it
does the job. If I could accidentally spill my
coffee and not have it cost $848, that would be
a cool feature.
But let us assume that you are not still
bitter from a recent laptop replacement. You
might stop to consider what the world might
be like, if computers the size of molecules
become a reality. These are the types of
computers that could be everywhere, but never
seen. Nano sized bio-computers that could target specific areas inside your body. Giant networks
of computers, in your clothing, your house, your car. Entrenched in almost every aspect of our
lives and yet you may never give them a single thought.
Understanding the theories behind these future computer technologies is not for the meek.
My research into quantum computers was made all the more difficult after I learned that in light
of her constant interference, it is theoretically possible my mother-in-law could be in two places
at once.
10
If you have the heart, take a gander at the most promising new computer technologies. If
not, dare to imagine the ways that billions of tiny, powerful computers will change our society.
.......................................................................................................................
Steve Jobs and Bill Gates were both instrumental in bringing the computer down to size.
With the introduction of the personal computer and its widespread acceptance, computers shrunk
while processing power increased. Even the bulky CRT monitors got a makeover with flat LCD
monitors now the norm. In addition, costs have fallen so much over the years that many
households own several personal computers and wireless networks. Future technology won't
necessarily render the home PC obsolete, but it will change it. For example, modern televisions
and appliances are now Web-enabled. Expect future technology to blend appliances into the
home network. I must admit that in some ways I envy Donald Trump. Not because of all the real
estate he owns or even for his cool private helicopter. No, what I envy most about The Donald is
his apprentice. Who wouldn't appreciate giving any chore that comes to mind, to an eager and
competent assistant? After time, a good apprentice might even anticipate your needs. "Pink tie
today, Mr. Trump?". Now apply this same kind of relationship model to the future of computing.
In the future, the number of tiny but powerful computers you encounter every day will number in
the thousands, perhaps millions. You won't see them, but they will be all around you. Your
personal interface to this powerful network of computers could come from a single computing
device that is worn on or in the body.
Aside from providing one 24/7 interface to the myriad of computers and sensors that you
will have access to, like a good apprentice, this computing device would come to know your
personal preferences and sometimes make decisions on your behalf.
…………………………………………………………………………………………….….
First there were laptops, then there were netbooks, and now there are "ultrabooks." These
mobile devices share several characteristics including the integrated folding design and
portability. Differences include size and storage (laptops use hard disks, netbooks rely more
heavily on the cloud, and ultrabooks use Flash memory). Despite their similarities and
differences, future computer trends point to a lesser reliance on keyboards which could
potentially render this category obsolete. Visit any site on the web writing about the future of
computers and you will most likely find mention of Moore's Law. Moore's Law is not a strictly
adhered to mathematical formula, but a prediction made by Intel's founder co-founder Gordon
Moore in 1965.
Moore predicted that computing technology would increase in value at the same time itld
decrease in cost. More specifically, that innovations in technology would allow a doubling of the
11
number of transistors in a given space every year, the speed of those transistors would increase
and manufacturing costs would drop.
A computer transistor acts like a small electronic switch. Just like the light switch on your
wall, a transistor has only two states, On or Off. A computer interprets this on/off state as a 1 or a
0. Put a whole bunch of these transistors together and you have a computer chip. The central
processing unit (CPU) inside your computer probably has around 500 million transistors.
Shrinking transistor size not only makes chips smaller, but faster. One benefit of packing
transistors closer together is that the electronic pulses take less time to travel between transistors.
This can increase the overall speed of the chip.
Not everyone agrees that Moore's Law has been accurate throughout the years, (the
prediction has changed since its original version), or that it will hold true in the future. But does
it really matter? The pace at which computers are doubling their smarts is happening fast enough
for me.
……………………………………………………………………………………………………...
Apple's iPad has significantly influenced future computer trends. It was soon followed by
a flood of tablets. With small sizes, simple designs, extreme portability, Internet access,
thousands of apps, and loads of features, tablets can do just about anything a full-size desktop or
laptop can do. They fall short in the keyboard arena, but again, that may be about to change.
……………………………………………………………………………………………………...
While speech recognition is still imperfect, it has improved greatly in recent years.
Windows 7 includes a built-in speech recognition program in its operating system while
Nuance's Dragon Naturally Speaking software continues to gain acceptance.
Not only is the keyboard in danger, the mouse is too thanks to touchscreen technology.
Tablets and smartphones currently make use of touchscreen technology and many "all in one"
desktops now come with touchscreen LCDs. When Windows 8 comes out, it is expected to take
the touchscreen into the mainstream. By 2020, laboratory experiments are yielding major
extensions in the lifespan of mice.* Since rodents and humans share similar DNA, there is now
real hope of defeating the aging process. Though a permanent "cure" remains a distant prospect,
a number of therapies are already in development which can help to reduce the cell damage,
mitochondrial mutations and other adverse effects of growing older.** These can be used as
bridges, to buy time for the more dramatic advances in the decades ahead. For those in middle
age or younger, the dream of being able to live indefinitely is moving from the realm of science
fiction to science fact. This period sees the beginning of major public interest and awareness of
the subject. At the same time, however, there is much opposition from religious institutions and
conservative groups.
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Exercise 2
Write your answers to these questions
1. Do you remember when the first primitive computing machines occupied entire
buildings?
2. Who is the main inventor of the modern computer?
3. Will future technology change our world? If, yes how will it change?
4. Can you imagine your life without using laptops?
5. Describe all the functions of Apple’s iPad?
6. Can new innovations replace the real world?
Exercise 3
Make a list of good and bad points about Future Computers, then discuss
these points in pairs, using the expressions from the Function File.
Function File
a) I’m really like these modern technologies, because…
b) What kind of points do you like better…?
c) What kind of points do you dislike…?
d) What other new innovation items do you invent…?
Exercise 4
Complete the description ‘Tablets’ with these words in the correct form.
Significantly, access, to be, to follow, tablets, desktop ,laptop, keyboard, simple.
Tablets
Apple's iPad has _____________influenced future computer trends.
It_____ soon __________by a flood of tablets. With_________ small sizes,
designs, extreme portability, Internet_______, thousands of apps, and loads of
features, _________ can do just about anything a full-size _________or_______
can do. They fall short in the_______ arena, but again, that may be about to
change.
Exercise 5
Write 10 sentences using these collocations and new vocabulary.
Get back, hit back, clean out, express thanks, go about, run in, express an opinion,
express horror, empty space, hard time.
2. Theme: Operating System
Introduction
An operating system (OS) is a collection of software that manages
computer hardware resources and provides common services for computer programs. The
operating system is a vital component of the system software in a computer system. Application
programs usually require an operating system to function.
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Time-sharing operating systems schedule tasks for efficient use of the system and may
also include accounting for cost allocation of processor time, mass storage, printing, and other
resources.
For hardware functions such as input and output and memory allocation, the operating
system acts as an intermediary between programs and the computer hardware, although the
application code is usually executed directly by the hardware and will frequently make a system
call to an OS function or be interrupted by it. Operating systems can be found on almost any
device that contains a computer—from cellular phones and video game consoles to
supercomputers and web servers.
Examples of popular modern operating systems include Android, BSD, iOS,
Linux, Mac OS X, Microsoft Windows, Windows Phone, and IBM z/OS. All these, except
Windows and z/OS, share roots in UNIX.
1. Types of operating systems
Real-time
A real-time operating system is a multitasking operating system that aims at executing
real-time applications. Real-time operating systems often use specialized scheduling algorithms
so that they can achieve a deterministic nature of behavior. The main objective of real-time
operating systems is their quick and predictable response to events. They have an event-driven or
time-sharing design and often aspects of both. An event-driven system switches between tasks
based on their priorities or external events while time-sharing operating systems switch tasks
based on clock interrupts.
Multi-user
A multi-user operating system allows multiple users to access a computer system at the
same time. Time-sharing systems and Internet servers can be classified as multi-user systems as
they enable multiple-user access to a computer through the sharing of time. Single-user operating
systems have only one user but may allow multiple programs to run at the same time.
Multi-tasking vs. single-tasking
A multi-tasking operating system allows more than one program to be running at a time,
from the point of view of human time scales. A single-tasking system has only one running
program. Multi-tasking can be of two types: pre-emptive or co-operative. In pre-emptive
multitasking, the operating system slices the CPU time and dedicates one slot to each of the
programs. Unix-like operating systems such as Solaris and Linux support pre-emptive
multitasking, as does AmigaOS. Cooperative multitasking is achieved by relying on each process
to give time to the other processes in a defined manner. 16-bit versions of Microsoft Windows
used cooperative multi-tasking. 32-bit versions, both Windows NT and Win9x, used pre-emptive
multi-tasking. Mac OS prior to OS X used to support cooperative multitasking.
Distributed
A distributed operating system manages a group of independent computers and makes
them appear to be a single computer. The development of networked computers that could be
linked and communicate with each other gave rise to distributed computing. Distributed
computations are carried out on more than one machine. When computers in a group work in
cooperation, they make a distributed system.
Embedded
Embedded operating systems are designed to be used in embedded computer systems.
They are designed to operate on small machines like PDAs with less autonomy. They are able to
operate with a limited number of resources. They are very compact and extremely efficient by
design. Windows CE and Minix 3 are some examples of embedded operating systems.
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2. History
Early computers were built to perform a series of single tasks, like a calculator. Operating
systems did not exist in their modern and more complex forms until the early 1960s. Basic
operating system features were developed in the 1950s, such as resident monitor functions that
could automatically run different programs in succession to speed up processing. Hardware
features were added that enabled use of runtime libraries, interrupts, and parallel processing.
When personal computers became popular in the 1980s, operating system were made for them
similar in concept to those used on larger computers.
In the 1940s, the earliest electronic digital systems had no operating systems. Electronic
systems of this time were programmed on rows of mechanical switches or by jumper wires on
plug boards. These were special-purpose systems that, for example, generated ballistics tables for
the military or controlled the printing of payroll checks from data on punched paper cards. After
programmable general purpose computers were invented, machine languages (consisting of
strings of the binary digits 0 and 1 on punched paper tape) were introduced that sped up the
programming process (Stern, 1981).
OS/360 was used on most IBM mainframe computers beginning in 1966, including the
computers that helped NASA put a man on the moon.
In the early 1950s, a computer could execute only one program at a time. Each user had
sole use of the computer for a limited period of time and would arrive at a scheduled time with
program and data on punched paper cards and/or punched tape. The program would be loaded
into the machine, and the machine would be set to work until the program completed or crashed.
Programs could generally be debugged via a front panel using toggle switches and panel lights. It
is said that Alan Turing was a master of this on the early Manchester Mark 1 machine, and he
was already deriving the primitive conception of an operating system from the principles of
the Universal Turing machine. Later machines came with libraries of programs, which would be
linked to a user's program to assist in operations such as input and output and
generating computer code from human-readable symbolic code. This was the genesis of the
modern-day computer system. However, machines still ran a single job at a time. At Cambridge
University in England the job queue was at one time a washing line from which tapes were hung
with different colored clothes-pegs to indicate job-priority.
3. Examples of operating systems
Unix was originally written in assembly language. Ken Thompson wrote B, mainly based
on BCPL, based on his experience in the MULTICS project. B was replaced by C, and Unix,
rewriten in C, developed into a large, complex family of inter-related operating systems which
have been influential in every modern operating system.
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The UNIX-like family is a diverse group of operating systems, with several major subcategories including System V, BSD, and Linux. The name "UNIX" is a trademark of The Open
Group which licenses it for use with any operating system that has been shown to conform to
their definitions. "UNIX-like" is commonly used to refer to the large set of operating systems
which resemble the original UNIX.
Unix-like systems run on a wide variety of computer architectures. They are used heavily
for servers in business, as well as workstations in academic and engineering
environments. Free UNIX variants, such as Linux and BSD, are popular in these areas.
Four operating systems are certified by the The Open Group (holder of the Unix
trademark) as Unix. HP's HP-UX and IBM's AIX are both descendants of the original System V
Unix and are designed to run only on their respective vendor's hardware. In contrast, Sun
Microsystems'sSolaris Operating System can run on multiple types of hardware,
including x86 and Sparc servers, and PCs. Apple's Mac OS X, a replacement for Apple's earlier
(non-Unix) Mac OS, is a hybrid kernel-based BSD variant derived from NeXTSTEP, Mach,
and FreeBSD.
Unix interoperability was sought by establishing the POSIX standard. The POSIX
standard can be applied to any operating system, although it was originally created for various
Unix variants.
BSD and its descendants
The first server for the World Wide Web ran on NeXTSTEP, based on BSD.
A subgroup of the Unix family is the Berkeley Software Distribution family, which
includes FreeBSD, NetBSD, and OpenBSD. These operating systems are most commonly found
on webservers, although they can also function as a personal computer OS. The Internet owes
much of its existence to BSD, as many of the protocols now commonly used by computers to
connect, send and receive data over a network were widely implemented and refined in BSD.
The world wide web was also first demonstrated on a number of computers running an OS based
on BSD calledNextStep.
BSD has its roots in Unix. In 1974, University of California, Berkeley installed its first
Unix system. Over time, students and staff in the computer science department there began
adding new programs to make things easier, such as text editors. When Berkely received
new VAX computers in 1978 with Unix installed, the school's undergraduates modified Unix
even more in order to take advantage of the computer's hardware possibilities. The Defense
Advanced Research Projects Agency of the US Department of Defense took interest, and
decided to fund the project. Many schools, corporations, and government organizations took
notice and started to use Berkeley's version of Unix instead of the official one distributed by
AT&T.
Steve Jobs, upon leaving Apple Inc. in 1985, formed NeXT Inc., a company that
manufactured high-end computers running on a variation of BSD called NeXTSTEP. One of
these computers was used by Tim Berners-Lee as the first webserver to create the World Wide
Web.
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Developers like Keith Bostic encouraged the project to replace any non-free code that
originated with Bell Labs. Once this was done, however, AT&T sued. Eventually, after two
years of legal disputes, the BSD project came out ahead and spawned a number of free
derivatives, such as FreeBSD and NetBSD.
Mac OS X is a line of open core graphical operating systems developed, marketed, and
sold by Apple Inc., the latest of which is pre-loaded on all currently
shipping Macintosh computers. Mac OS X is the successor to the original Mac OS, which had
been Apple's primary operating system since 1984. Unlike its predecessor, Mac OS X is
a UNIX operating system built on technology that had been developed at NeXT through the
second half of the 1980s and up until Apple purchased the company in early 1997. The operating
system was first released in 1999 as Mac OS X Server 1.0, with a desktop-oriented version (Mac
OS X v10.0 "Cheetah") following in March 2001. Since then, six more distinct "client" and
"server" editions of Mac OS X have been released, the most recent being OS X 10.8 "Mountain
Lion", which was first made available on February 16, 2012 for developers, and was then
released to the public on July 25, 2012. Releases of Mac OS X are named after big cats.
The server edition, Mac OS X Server, is architecturally identical to its desktop
counterpart but usually runs on Apple's line of Macintosh serverhardware. Mac OS X Server
includes work group management and administration software tools that provide simplified
access to key network services, including a mail transfer agent, a Samba server, an LDAP server,
a domain name server, and others. In Mac OS X v10.7 Lion, all server aspects of Mac OS X
Server have been integrated into the client version.
Linux (or GNU/Linux) is a Unix-like operating system that was developed without any
actual Unix code, unlike BSD and its variants. Linux can be used on a wide range of devices
from supercomputers to wristwatches. TheLinux kernel is released under an open source license,
so anyone can read and modify its code. It has been modified to run on a large variety of
electronics. Although estimates suggest that Linux is used on 1.82% of all personal computers, it
has been widely adopted for use in servers and embedded systems (such as cell phones). Linux
has superseded Unix in most places, and is used on the 10 most powerful supercomputers in the
world. The Linux kernel is used in some popular distributions, such as Red
Hat,Debian, Ubuntu, Linux Mint and Google's Android.
The GNU project is a mass collaboration of programmers who seek to create a
completely free and open operating system that was similar to Unix but with completely original
code. It was started in 1983 by Richard Stallman, and is responsible for many of the parts of
most Linux variants. Thousands of pieces of software for virtually every operating system are
licensed under the GNU General Public License. Meanwhile, the Linux kernel began as a side
project of Linus Torvalds, a university student from Finland. In 1991, Torvalds began work on it,
and posted information about his project on a newsgroup for computer students and
programmers. He received a wave of support and volunteers who ended up creating a fullfledged kernel. Programmers from GNU took notice, and members of both projects worked to
integrate the finished GNU parts with the Linux kernel in order to create a full-fledged operating
system.
Chrome is an operating system based on the Linux kernel and designed by Google. Since
Chrome OS targets computer users who spend most of their time on the Internet, it is mainly
a web browser with no ability to run applications. It relies on Internet applications (or Web apps)
used in the web browser to accomplish tasks such as word processing and media viewing, as well
as online storage for storing most files.
Microsoft Windows is a family of proprietary operating systems designed by Microsoft
Corporation and primarily targeted to Intel architecture based computers, with an estimated 88.9
percent total usage share on Web connected computers. The newest version is Windows 8 for
workstations and Windows Server 2012 for servers. Windows 7 recently overtook Windows XP
as most used OS.
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Microsoft Windows originated in 1985 as an operating environment running on top
of MS-DOS, which was the standard operating system shipped on most Intel architecture
personal computers at the time. In 1995, Windows 95 was released which only used MS-DOS as
a bootstrap. For backwards compatibility, Win9x could run real-mode MS-DOS and 16
bits Windows 3.x drivers. Windows Me, released in 2000, was the last version in the Win9x
family. Later versions have all been based on the Windows NT kernel. Current versions of
Windows run on IA-32 and x86-64 microprocessors, although Windows 8 will
support ARM architecture. In the past, Windows NT supported non-Intel architectures.
Server editions of Windows are widely used. In recent years, Microsoft has expended
significant capital in an effort to promote the use of Windows as a server operating system.
However, Windows' usage on servers is not as widespread as on personal computers, as
Windows competes against Linux and BSD for server
market share.
There have been many operating systems that were significant in their day but are no
longer so, such as AmigaOS; OS/2 from IBM and Microsoft;Mac OS, the non-Unix precursor to
Apple's Mac OS X; BeOS; XTS-300; RISC OS; MorphOS and FreeMint. Some are still used in
niche markets and continue to be developed as minority platforms for enthusiast communities
and specialist applications. OpenVMS formerly from DEC, is still under active development
by Hewlett-Packard. Yet other operating systems are used almost exclusively in academia, for
operating systems education or to do research on operating system concepts. A typical example
of a system that fulfills both roles is MINIX, while for exampleSingularity is used purely for
research.
Other operating systems have failed to win significant market share, but have introduced
innovations that have influenced mainstream operating systems, not least Bell Labs' Plan 9.
4. Components
The components of an operating system all exist in order to make the different parts of a
computer work together. All user software needs to go through the operating system in order to
use any of the hardware, whether it be as simple as a mouse or keyboard or as complex as an
Internet component.
A kernel connects the application software to the hardware of a computer.
With the aid of the firmware and device drivers, the kernel provides the most basic level
of control over all of the computer's hardware devices. It manages memory access for programs
in the RAM, it determines which programs get access to which hardware resources, it sets up or
resets the CPU's operating states for optimal operation at all times, and it organizes the data for
long-term non-volatile storage with file systems on such media as disks, tapes, flash memory,
etc.
The operating system provides an interface between an application program and the
computer hardware, so that an application program can interact with the hardware only by
obeying rules and procedures programmed into the operating system. The operating system is
also a set of services which simplify development and execution of application programs.
Executing an application program involves the creation of a process by the operating
18
system kernel which assigns memory space and other resources, establishes a priority for the
process in multi-tasking systems, loads program binary code into memory, and initiates
execution of the application program which then interacts with the user and with hardware
devices.
Interrupts are central to operating systems, as they provide an efficient way for the
operating system to interact with and react to its environment. The alternative — having the
operating system "watch" the various sources of input for events (polling) that require action —
can be found in older systems with very small stacks (50 or 60 bytes) but are unusual in modern
systems with large stacks. Interrupt-based programming is directly supported by most modern
CPUs. Interrupts provide a computer with a way of automatically saving local register contexts,
and running specific code in response to events. Even very basic computers support hardware
interrupts, and allow the programmer to specify code which may be run when that event takes
place.
When an interrupt is received, the computer's hardware automatically suspends whatever
program is currently running, saves its status, and runs computer code previously associated with
the interrupt; this is analogous to placing a bookmark in a book in response to a phone call. In
modern operating systems, interrupts are handled by the operating system's kernel. Interrupts
may come from either the computer's hardware or from the running program.
When a hardware device triggers an interrupt, the operating system's kernel decides how
to deal with this event, generally by running some processing code. The amount of code being
run depends on the priority of the interrupt (for example: a person usually responds to a smoke
detector alarm before answering the phone). The processing of hardware interrupts is a task that
is usually delegated to software called device driver, which may be either part of the operating
system's kernel, part of another program, or both. Device drivers may then relay information to a
running program by various means.
A program may also trigger an interrupt to the operating system. If a program wishes to
access hardware for example, it may interrupt the operating system's kernel, which causes
control to be passed back to the kernel. The kernel will then process the request. If a program
wishes additional resources (or wishes to shed resources) such as memory, it will trigger an
interrupt to get the kernel's attention.
Privilege rings for the x86 available in protected mode.
Operating systems determine which processes run in each mode.
Modern CPUs support multiple modes of operation. CPUs with this capability use at least
two modes: protected mode and supervisor mode. The supervisor mode is used by the operating
system's kernel for low level tasks that need unrestricted access to hardware, such as controlling
how memory is written and erased, and communication with devices like graphics cards.
Protected mode, in contrast, is used for almost everything else. Applications operate within
protected mode, and can only use hardware by communicating with the kernel, which controls
19
everything in supervisor mode. CPUs might have other modes similar to protected mode as well,
such as the virtual modes in order to emulate older processor types, such as 16-bit processors on
a 32-bit one, or 32-bit processors on a 64-bit one.
When a computer first starts up, it is automatically running in supervisor mode. The first
few programs to run on the computer, being theBIOS or EFI, bootloader, and the operating
system have unlimited access to hardware - and this is required because, by definition,
initializing a protected environment can only be done outside of one. However, when the
operating system passes control to another program, it can place the CPU into protected mode.
In protected mode, programs may have access to a more limited set of the CPU's
instructions. A user program may leave protected modeonly by triggering an interrupt, causing
control to be passed back to the kernel. In this way the operating system can maintain exclusive
control over things like access to hardware and memory.
The term "protected mode resource" generally refers to one or more CPU registers, which
contain information that the running program isn't allowed to alter. Attempts to alter these
resources generally causes a switch to supervisor mode, where the operating system can deal
with the illegal operation the program was attempting (for example, by killing the program).
Among other things, a multiprogramming operating system kernel must be responsible
for managing all system memory which is currently in use by programs. This ensures that a
program does not interfere with memory already in use by another program. Since programs time
share, each program must have independent access to memory.
Cooperative memory management, used by many early operating systems, assumes that
all programs make voluntary use of the kernel's memory manager, and do not exceed their
allocated memory. This system of memory management is almost never seen any more, since
programs often contain bugs which can cause them to exceed their allocated memory. If a
program fails, it may cause memory used by one or more other programs to be affected or
overwritten. Malicious programs or viruses may purposefully alter another program's memory,
or may affect the operation of the operating system itself. With cooperative memory
management, it takes only one misbehaved program to crash the system.
Memory protection enables the kernel to limit a process' access to the computer's
memory.
Various
methods
of
memory
protection
exist,
including memory
segmentation and paging. All methods require some level of hardware support (such as
the 80286 MMU), which doesn't exist in all computers.
In both segmentation and paging, certain protected mode registers specify to the CPU
what memory address it should allow a running program to access. Attempts to access other
addresses will trigger an interrupt which will cause the CPU to re-enter supervisor mode, placing
the kernel in charge. This is called a segmentation violation or Seg-V for short, and since it is
both difficult to assign a meaningful result to such an operation, and because it is usually a sign
of a misbehaving program, the kernel will generally resort to terminating the offending program,
and will report the error.
Windows 3.1-Me had some level of memory protection, but programs could easily
circumvent the need to use it. A general protection fault would be produced, indicating a
segmentation violation had occurred; however, the system would often crash anyway.
The use of virtual memory addressing (such as paging or segmentation) means that the
kernel can choose what memory each program may use at any given time, allowing the operating
system to use the same memory locations for multiple tasks.
If a program tries to access memory that isn't in its current range of accessible memory,
but nonetheless has been allocated to it, the kernel will be interrupted in the same way as it
would if the program were to exceed its allocated memory. (See section on memory
management.) Under UNIX this kind of interrupt is referred to as a page fault.
When the kernel detects a page fault it will generally adjust the virtual memory range of
the program which triggered it, granting it access to the memory requested. This gives the kernel
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discretionary power over where a particular application's memory is stored, or even whether or
not it has actually been allocated yet.
In modern operating systems, memory which is accessed less frequently can be
temporarily stored on disk or other media to make that space available for use by other programs.
This is called swapping, as an area of memory can be used by multiple programs, and what that
memory area contains can be swapped or exchanged on demand.
"Virtual memory" provides the programmer or the user with the perception that there is a
much larger amount of RAM in the computer than is really there.
Multitasking refers to the running of multiple independent computer programs on the
same computer; giving the appearance that it is performing the tasks at the same time. Since
most computers can do at most one or two things at one time, this is generally done via timesharing, which means that each program uses a share of the computer's time to execute.
An operating system kernel contains a piece of software called a scheduler which
determines how much time each program will spend executing, and in which order execution
control should be passed to programs. Control is passed to a process by the kernel, which allows
the program access to the CPU and memory. Later, control is returned to the kernel through
some mechanism, so that another program may be allowed to use the CPU. This so-called
passing of control between the kernel and applications is called a context switch.
An early model which governed the allocation of time to programs was
called cooperative multitasking. In this model, when control is passed to a program by the
kernel, it may execute for as long as it wants before explicitly returning control to the kernel.
This means that a malicious or malfunctioning program may not only prevent any other
programs from using the CPU, but it can hang the entire system if it enters an infinite loop.
Modern operating systems extend the concepts of application preemption to device
drivers and kernel code, so that the operating system has preemptive control over internal runtimes as well.
The philosophy governing preemptive multitasking is that of ensuring that all programs
are given regular time on the CPU. This implies that all programs must be limited in how much
time they are allowed to spend on the CPU without being interrupted. To accomplish this,
modern operating system kernels make use of a timed interrupt. A protected mode timer is set by
the kernel which triggers a return to supervisor mode after the specified time has elapsed. (See
above sections on Interrupts and Dual Mode Operation.)
On many single user operating systems cooperative multitasking is perfectly adequate, as
home computers generally run a small number of well tested programs. The AmigaOS is an
exception, having pre-emptive multitasking from its very first version. Windows NT was the first
version of Microsoft Windows which enforced preemptive multitasking, but it didn't reach the
home user market until Windows XP (since Windows NT was targeted at professionals).
Access to data stored on disks is a central feature of all operating systems. Computers
store data on disks using files, which are structured in specific ways in order to allow for faster
access, higher reliability, and to make better use out of the drive's available space. The specific
way in which files are stored on a disk is called a file system, and enables files to have names
and attributes. It also allows them to be stored in a hierarchy of directories or folders arranged in
a directory tree.
Early operating systems generally supported a single type of disk drive and only one kind
of file system. Early file systems were limited in their capacity, speed, and in the kinds of file
names and directory structures they could use. These limitations often reflected limitations in the
operating systems they were designed for, making it very difficult for an operating system to
support more than one file system.
While many simpler operating systems support a limited range of options for accessing
storage systems, operating systems like UNIX and Linuxsupport a technology known as a virtual
file system or VFS. An operating system such as UNIX supports a wide array of storage devices,
21
regardless of their design or file systems, allowing them to be accessed through a
common application programming interface (API). This makes it unnecessary for programs to
have any knowledge about the device they are accessing. A VFS allows the operating system to
provide programs with access to an unlimited number of devices with an infinite variety of file
systems installed on them, through the use of specific device driversand file system drivers.
A connected storage device, such as a hard drive, is accessed through a device driver. The
device driver understands the specific language of the drive and is able to translate that language
into a standard language used by the operating system to access all disk drives. On UNIX, this is
the language of block devices.
When the kernel has an appropriate device driver in place, it can then access the contents
of the disk drive in raw format, which may contain one or more file systems. A file system driver
is used to translate the commands used to access each specific file system into a standard set of
commands that the operating system can use to talk to all file systems. Programs can then deal
with these file systems on the basis of filenames, and directories/folders, contained within a
hierarchical structure. They can create, delete, open, and close files, as well as gather various
information about them, including access permissions, size, free space, and creation and
modification dates.
Various differences between file systems make supporting all file systems difficult.
Allowed characters in file names, case sensitivity, and the presence of various kinds of file
attributes makes the implementation of a single interface for every file system a daunting task.
Operating systems tend to recommend using (and so support natively) file systems specifically
designed for them; for example, NTFS in Windows and ext3 and ReiserFS in Linux. However,
in practice, third party drives are usually available to give support for the most widely used file
systems in most general-purpose operating systems (for example, NTFS is available in Linux
through NTFS-3g, and ext2/3 and ReiserFS are available in Windows through third-party
software).
Support for file systems is highly varied among modern operating systems, although there
are several common file systems which almost all operating systems include support and drivers
for. Operating systems vary on file system support and on the disk formats they may be installed
on. Under Windows, each file system is usually limited in application to certain media; for
example, CDs must use ISO 9660 or UDF, and as of Windows Vista, NTFS is the only file
system which the operating system can be installed on. It is possible to install Linux onto many
types of file systems. Unlike other operating systems, Linux and UNIX allow any file system to
be used regardless of the media it is stored in, whether it is a hard drive, a disc (CD,DVD...), a
USB flash drive, or even contained within a file located on another file system.
A device driver is a specific type of computer software developed to allow interaction
with hardware devices. Typically this constitutes an interface for communicating with the
device, through the specific computer bus or communications subsystem that the hardware is
connected to, providing commands to and/or receiving data from the device, and on the other
end, the requisite interfaces to the operating system and software applications. It is a specialized
hardware-dependent computer program which is also operating system specific that enables
another program, typically an operating system or applications software package or computer
program running under the operating system kernel, to interact transparently with a hardware
device, and usually provides the requisite interrupt handling necessary for any necessary
asynchronous time-dependent hardware interfacing needs.
The key design goal of device drivers is abstraction. Every model of hardware (even
within the same class of device) is different. Newer models also are released by manufacturers
that provide more reliable or better performance and these newer models are often controlled
differently. Computers and their operating systems cannot be expected to know how to control
every device, both now and in the future. To solve this problem, operating systems essentially
dictate how every type of device should be controlled. The function of the device driver is then
to translate these operating system mandated function calls into device specific calls. In theory a
22
new device, which is controlled in a new manner, should function correctly if a suitable driver is
available. This new driver will ensure that the device appears to operate as usual from the
operating system's point of view.
Under versions of Windows before Vista and versions of Linux before 2.6, all driver
execution was co-operative, meaning that if a driver entered an infinite loop it would freeze the
system. More recent revisions of these operating systems incorporate kernel preemption, where
the kernel interrupts the driver to give it tasks, and then separates itself from the process until it
receives a response from the device driver, or gives it more tasks to do.
Currently most operating systems support a variety of networking protocols, hardware,
and applications for using them. This means that computers running dissimilar operating systems
can participate in a common network for sharing resources such as computing, files, printers, and
scanners using either wired or wireless connections. Networks can essentially allow a computer's
operating system to access the resources of a remote computer to support the same functions as it
could if those resources were connected directly to the local computer. This includes everything
from simple communication, to using networked file systems or even sharing another computer's
graphics or sound hardware. Some network services allow the resources of a computer to be
accessed transparently, such as SSH which allows networked users direct access to a computer's
command line interface.
Client/server networking allows a program on a computer, called a client, to connect via a
network to another computer, called a server. Servers offer (or host) various services to other
network computers and users. These services are usually provided through ports or numbered
access points beyond the server's network address. Each port number is usually associated with a
maximum of one running program, which is responsible for handling requests to that port. A
daemon, being a user program, can in turn access the local hardware resources of that computer
by passing requests to the operating system kernel.
Many operating systems support one or more vendor-specific or open networking
protocols as well, for example, SNA on IBM systems, DECnet on systems from Digital
Equipment Corporation, and Microsoft-specific protocols (SMB) on Windows. Specific
protocols for specific tasks may also be supported such as NFS for file access. Protocols
like ESound, or esd can be easily extended over the network to provide sound from local
applications, on a remote system's sound hardware.
A computer being secure depends on a number of technologies working properly. A
modern operating system provides access to a number of resources, which are available to
software running on the system, and to external devices like networks via the kernel.
The operating system must be capable of distinguishing between requests which should
be allowed to be processed, and others which should not be processed. While some systems may
simply distinguish between "privileged" and "non-privileged", systems commonly have a form
of requester identity, such as a user name. To establish identity there may be a process
of authentication. Often a username must be quoted, and each username may have a password.
Other methods of authentication, such as magnetic cards or biometric data, might be used
instead. In some cases, especially connections from the network, resources may be accessed with
no authentication at all (such as reading files over a network share). Also covered by the concept
of requester identity is authorization; the particular services and resources accessible by the
requester once logged into a system are tied to either the requester's user account or to the
variously configured groups of users to which the requester belongs.
In addition to the allow/disallow model of security, a system with a high level of security
will also offer auditing options. These would allow tracking of requests for access to resources
(such as, "who has been reading this file?"). Internal security, or security from an already
running program is only possible if all possibly harmful requests must be carried out through
interrupts to the operating system kernel. If programs can directly access hardware and
resources, they cannot be secured.
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External security involves a request from outside the computer, such as a login at a
connected console or some kind of network connection. External requests are often passed
through device drivers to the operating system's kernel, where they can be passed onto
applications, or carried out directly. Security of operating systems has long been a concern
because of highly sensitive data held on computers, both of a commercial and military nature.
The United States Government Department of Defense (DoD) created the Trusted Computer
System Evaluation Criteria (TCSEC) which is a standard that sets basic requirements for
assessing the effectiveness of security. This became of vital importance to operating system
makers, because the TCSEC was used to evaluate, classify and select trusted operating
systems being considered for the processing, storage and retrieval of sensitive or classified
information.
Network services include offerings such as file sharing, print services, email, web sites,
and file transfer protocols (FTP), most of which can have compromised security. At the front line
of security are hardware devices known as firewalls or intrusion detection/prevention systems.
At the operating system level, there are a number of software firewalls available, as well as
intrusion detection/prevention systems. Most modern operating systems include a software
firewall, which is enabled by default. A software firewall can be configured to allow or deny
network traffic to or from a service or application running on the operating system. Therefore,
one can install and be running an insecure service, such as Telnet or FTP, and not have to be
threatened by security breach because the firewall would deny all traffic trying to connect to the
service on that port.
An alternative strategy, and the only sandbox strategy available in systems that do not
meet the Popek and Goldberg virtualization requirements, is the operating system not running
user programs as native code, but instead either emulates a processor or provides a host for a pcode based system such as Java.
Internal security is especially relevant for multi-user systems; it allows each user of the
system to have private files that the other users cannot tamper with or read. Internal security is
also vital if auditing is to be of any use, since a program can potentially bypass the operating
system, inclusive of bypassing auditing.
Every computer that is to be operated by an individual requires a user interface. The user
interface is usually referred to as a shell and is essential if human interaction is to be supported.
The user interface views the directory structure and requests services from the operating system
that will acquire data from input hardware devices, such as a keyboard, mouse or credit card
reader, and requests operating system services to displayprompts, status messages and such
on output hardware devices, such as a video monitor or printer. The two most common forms of
a user interface have historically been the command-line interface, where computer commands
are typed out line-by-line, and the graphical user interface, where a visual environment (most
commonly a WIMP) is present.
A screenshot of the KDE Plasma Desktopgraphical user interface. Programs take the
form of images on the screen, and the files, folders (directories), and applications take the form
of icons and symbols. A mouse is used to navigate the computer.
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Most of the modern computer systems support graphical user interfaces (GUI), and often
include them. In some computer systems, such as the original implementation of Mac OS, the
GUI is integrated into the kernel.
While technically a graphical user interface is not an operating system service,
incorporating support for one into the operating system kernel can allow the GUI to be more
responsive by reducing the number of context switches required for the GUI to perform its
output functions. Other operating systems are modular, separating the graphics subsystem from
the kernel and the Operating System. In the 1980s UNIX, VMS and many others had operating
systems that were built this way. Linux and Mac OS X are also built this way. Modern releases
of Microsoft Windows such as Windows Vista implement a graphics subsystem that is mostly in
user-space; however the graphics drawing routines of versions between Windows NT
4.0 and Windows Server 2003 exist mostly in kernel space. Windows 9x had very little
distinction between the interface and the kernel.
Many computer operating systems allow the user to install or create any user interface
they desire. The X Window System in conjunction withGNOME or KDE Plasma Desktop is a
commonly found setup on most Unix and Unix-like (BSD, Linux, Solaris) systems. A number
of Windows shell replacements have been released for Microsoft Windows, which offer
alternatives to the included Windows shell, but the shell itself cannot be separated from
Windows.
Numerous Unix-based GUIs have existed over time, most derived from X11.
Competition among the various vendors of Unix (HP, IBM, Sun) led to much fragmentation,
though an effort to standardize in the 1990s to COSE and CDE failed for various reasons, and
were eventually eclipsed by the widespread adoption of GNOME and K Desktop Environment.
Prior to free software-based toolkits and desktop environments, Motif was the prevalent
toolkit/desktop combination (and was the basis upon which CDE was developed).
Graphical user interfaces evolve over time. For example, Windows has modified its user
interface almost every time a new major version of Windows is released, and the Mac OS GUI
changed dramatically with the introduction of Mac OS X in 1999.
A real-time operating system (RTOS) is a multitasking operating system intended for
applications with fixed deadlines (real-time computing). Such applications include some
small embedded systems, automobile engine controllers, industrial robots, spacecraft, industrial
control, and some large-scale computing systems.
An early example of a large-scale real-time operating system was Transaction Processing
Facility developed by American Airlines and IBM for the Sabre Airline Reservations System.
Embedded systems that have fixed deadlines use a real-time operating
system suchas VxWorks, PikeOS, eCos, QNX, MontaVista,Linux and RTLinux. Windows CE is
a real-time operating system that shares similar APIs to desktop Windows but shares none of
desktop Windows' codebase. Symbian OS also has an RTOS kernel (EKA2) starting with
version 8.0b.
Some embedded systems use operating systems such as Palm OS, BSD, and Linux,
although such operating systems do not support real-time computing.
Operating system development is one of the most complicated activities in which a
computing hobbyist may engage. A hobby operating system may be classified as one whose code
has not been directly derived from an existing operating system, and has few users and active
developers. http://en.wikipedia.org/wiki/Operating_system - cite_note-25
In some cases, hobby development is in support of a "homebrew" computing device, for
example, a simple single-board computer powered by a 6502 microprocessor. Or, development
may be for an architecture already in widespread use. Operating system development may come
from entirely new concepts, or may commence by modeling an existing operating system. In
either case, the hobbyist is his/her own developer, or may interact with a small and sometimes
unstructured group of individuals who have like interests.
Examples of a hobby operating system include ReactOS and Syllable.
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Application software is generally written for use on a specific operating system, and
sometimes even for specific hardware. When porting the application to run on another OS, the
functionality required by that application may be implemented differently by that OS (the names
of functions, meaning of arguments, etc.) requiring the application to be adapted, changed, or
otherwise maintained.
This cost in supporting operating systems diversity can be avoided by instead writing
applications against software platforms like Java or Qt. These abstractions have already borne
the cost of adaptation to specific operating systems and their system libraries.
Another approach is for operating system vendors to adopt standards. For
example, POSIX and OS abstraction layers provide commonalities that reduce porting costs.
Exercise 1
Draw a line to match the operating system to the correct type of computer.
1. Windows 98
Macintosh
2. System 8
3. Windows 2000
4. Windows 95
PC
5. System 7
Draw a line from the part of the operating system to the place it is stored in a computer.
6. Essential OS - contains programs
that the computer needs to run proper
Hard Drive
7. Non-essential OS - programs that are
important, but not essential to making
the computer run.
ROM
Exercise 2
Vocabulary Worksheet
Fill in the blanks with the vocabulary words from the box below.
Use each word only one time.
Hard drive, user friendly, DOS, Windows, essential, operating system, upgraded,
graphics, BIOS, System 8.
1. The large program that controls how the CPU communicates with other hardware
components is the__________________.
2. A computer that is easy to operate is called________________.
3. The _______________wakes up the computer and reminds it what to do.
4. The ______________ part of the operating system is stored on ROM.
5. The ______________ part of the operating system is stored on ROM.
6. Important, but non-essential, parts of the operating system are stored
on the computer's ____________.
7. Disk-based Operating System is also known as _______________.
8. _____________ is the most common operating system for PCs.
9. Operating systems are constantly being _______________ as technology advances.
10. One example of a Macintosh operating system is ________________.
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11. A Graphical User Interface uses _______to help the user navigate within the computer
system.
Exercise 3
Read these questions, then find answers in the text.
1.
2.
3.
4.
5.
6.
7.
What types of (OS) do you know? Name them .
Had early computers (OS) systems?
What Operating Systems’ examples do you know?
What are the main components of (OS)?
When does the first computer start up to run automatically?
What is memory protection? Explain it.
What is the difference between the Microsoft Windows and Linux (OS)? Give the
extended answer.
8. What is the main aim of the (OS)?
9. What does modern (OS) include?
10. Describe all the processes in the Operating System’s evolution.
11. Give the prominent and the most useful examples of (OS)?
Exercise 4
Read the text again, decide if these sentences are true (T) or false (F). Then
check your answers.
___ An (OS)is a collection of software that manages computer hardware resources and provides
common services for computer programs.
___ (OS) can not be found on almost any device that contains a computer – from cellular phones
and video game consoles to sypercomputers and web servers.
___ A multi-user (OS) does not allow multiple users to access a computer system at the same
time.
___ When computers in a group work in cooperation, make a distributed system.
___ Embedded (OS) are not designed to be used in embedded computer systems.
___Early computers were built to perform a series of signal tasks, like a calculator.
___ In the 1940s, the earliest electronic digital systems had no (OS).
___ In the 1950s, a computer could execute only two programs at a time.
___ Linex was originally written in assembly language.
___ The Unix – like family is a device group of (OS), with several major sub-categories
including System V, BSD, and Linux.
Exercise 5
Match the sentences (1-7) with their endings (a-g) to make the statements.
1.
2.
3.
4.
5.
6.
7.
______
______
______
______
______
______
______
Hardware functions such as input and output and memory,
Application programs usually
A real-time (OS) is a multitasking (OS)
Distributed (OS) manages a group of
(OS) did not exist in their modern
Linux is a Unix – like (OS) that was
The newest version is Windows 8
a) _______ independent computers and makes them appear to be a signal computer.
b) _______ require an (OS) to function.
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c) _______
d) _______
e) _______
f) _______
g) _______
that aims at executing real-time applications.
and more complex forms until the early 1960s.
for workstations and Windows Server 2012 for servers.
depended without any actual Unix code, unlike DSD and its variants.
the (OS) acts as an intermediately between programs and the computer hardware.
Exercise 6
Make sentences by the following words using new vocabulary.
Server, to support, the GNU project, to run, application, embed, to base, effort, significant,
innovation.
Exercise 7
Write short summaries to the following topics.
 _______ Examples of Operating System
 _______ Operating System’s History
 _______ Operating system Componets
3.Theme: Computers’ Development History
Computer History and Development
Nothing epitomizes modern life better than the computer. For better or worse, computers
have infiltrated every aspect of our society. Today computers do much more than simply
compute: supermarket scanners calculate our grocery bill while keeping store inventory;
computerized telephone switching centers play traffic cop to millions of calls and keep lines of
communication untangled; and automatic teller machines (ATM) let us conduct banking
transactions from virtually anywhere in the world. But where did all this technology come from
and where is it heading? To fully understand and appreciate the impact computers have on our
lives and promises they hold for the future, it is important to understand their evolution.
1. Early Computing Machines and Inventors
The abacus, which emerged about 5,000 years ago in Asia Minor and is still in use today,
may be considered the first computer. This device allows users to make computations using a
system of sliding beads arranged on a rack. Early merchants used the abacus to keep trading
transactions. But as the use of paper and pencil spread, particularly in Europe, the abacus lost its
importance. It took nearly 12 centuries, however, for the next significant advance in computing
devices to emerge. In 1642, Blaise Pascal (1623-1662), the 18-year-old son of a French tax
collector, invented what he called a numerical wheel calculator to help his father with his duties.
This brass rectangular box, also called a Pascaline, used eight movable dials to add sums up to
eight figures long. Pascal's device used a base of ten to accomplish this. For example, as one dial
moved ten notches, or one complete revolution, it moved the next dial - which represented the
ten's column - one place. When the ten's dial moved one revolution, the dial representing the
hundred's place moved one notch and so on. The drawback to the Pascaline, of course, was its
limitation to addition.
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In 1694, a German mathematician and philosopher, Gottfried Wilhem von Leibniz (16461716), improved the Pascaline by creating a machine that could also multiply. Like its
predecessor, Leibniz's mechanical multiplier worked by a system of gears and dials. Partly by
studying Pascal's original notes and drawings, Leibniz was able to refine his machine. The
centerpiece of the machine was its stepped-drum gear design, which offered an elongated version
of the simple flat gear. It wasn't until 1820, however, that mechanical calculators gained
widespread use. Charles Xavier Thomas de Colmar, a Frenchman, invented a machine that could
perform the four basic arithmetic functions. Colmar's mechanical calculator, the arithometer,
presented a more practical approach to computing because it could add, subtract, multiply and
divide. With its enhanced versatility, the arithometer was widely used up until the First World
War. Although later inventors refined Colmar's calculator, together with fellow inventors Pascal
and Leibniz, he helped define the age of mechanical computation.
The real beginnings of computers as we know them today, however, lay with an English
mathematics professor, Charles Babbage (1791-1871). Frustrated at the many errors he found
while examining calculations for the Royal Astronomical Society, Babbage declared, "I wish to
God these calculations had been performed by steam!" With those words, the automation of
computers had begun. By 1812, Babbage noticed a natural harmony between machines and
mathematics: machines were best at performing tasks repeatedly without mistake; while
mathematics, particularly the production of mathematics tables, often required the simple
repetition of steps. The problem centered on applying the ability of machines to the needs of
mathematics. Babbage's first attempt at solving this problem was in 1822 when he proposed a
machine to perform differential equations, called a Difference Engine. Powered by steam and
large as a locomotive, the machine would have a stored program and could perform calculations
and print the results automatically.
After working on the Difference Engine for 10 years, Babbage was suddenly inspired to
begin work on the first general-purpose computer, which he called the Analytical Engine.
Babbage's assistant, Augusta Ada King, Countess of Lovelace (1815-1842) and daughter of
English poet Lord Byron, was instrumental in the machine's design. One of the few people who
understood the Engine's design as well as Babbage, she helped revise plans, secure funding from
the British government, and communicate the specifics of the Analytical Engine to the public.
Also, Lady Lovelace's fine understanding of the machine allowed her to create the instruction
routines to be fed into the computer, making her the first female computer programmer. In the
1980's, the U.S. Defense Department named a programming language ADA in her honor.
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Babbage's steam-powered Engine, although ultimately never constructed, may seem
primitive by today's standards. However, it outlined the basic elements of a modern general
purpose computer and was a breakthrough concept. Consisting of over 50,000 components, the
basic design of the Analytical Engine included input devices in the form of perforated cards
containing operating instructions and a "store" for memory of 1,000 numbers of up to 50 decimal
digits long. It also contained a "mill" with a control unit that allowed processing instructions in
any sequence, and output devices to produce printed results. Babbage borrowed the idea of
punch cards to encode the machine's instructions from the Jacquard loom. The loom, produced in
1820 and named after its inventor, Joseph-Marie Jacquard, used punched boards that controlled
the patterns to be woven.
In 1889, an American inventor, Herman Hollerith (1860-1929), also applied the Jacquard
loom concept to computing. His first task was to find a faster way to compute the U.S. census.
The previous census in 1880 had taken nearly seven years to count and with an expanding
population, the bureau feared it would take 10 years to count the latest census. Unlike Babbage's
idea of using perforated cards to instruct the machine, Hollerith's method used cards to store data
information which he fed into a machine that compiled the results mechanically. Each punch on
a card represented one number, and combinations of two punches represented one letter. As
many as 80 variables could be stored on a single card. Instead of ten years, census takers
compiled their results in just six weeks with Hollerith's machine. In addition to their speed, the
punch cards served as a storage method for data and they helped reduce computational errors.
Hollerith brought his punch card reader into the business world, founding Tabulating Machine
Company in 1896, later to become International Business Machines (IBM) in 1924 after a series
of mergers. Other companies such as Remington Rand and Burroghs also manufactured punch
readers for business use. Both business and government used punch cards for data processing
until the 1960's.
In the ensuing years, several engineers made other significant advances. Vannevar Bush
(1890-1974) developed a calculator for solving differential equations in 1931. The machine
could solve complex differential equations that had long left scientists and mathematicians
baffled. The machine was cumbersome because hundreds of gears and shafts were required to
represent numbers and their various relationships to each other. To eliminate this bulkiness, John
V. Atanasoff (b. 1903), a professor at Iowa State College (now called Iowa State University) and
his graduate student, Clifford Berry, envisioned an all-electronic computer that applied Boolean
algebra to computer circuitry. This approach was based on the mid-19th century work of George
Boole (1815-1864) who clarified the binary system of algebra, which stated that any
mathematical equations could be stated simply as either true or false. By extending this concept
to electronic circuits in the form of on or off, Atanasoff and Berry had developed the first allelectronic computer by 1940. Their project, however, lost its funding and their work was
overshadowed by similar developments by other scientists.
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2. Five Generations of Computers
 First Generation (1945-1956)
With the onset of the Second World War, governments sought to develop computers to
exploit their potential strategic importance. This increased funding for computer development
projects hastened technical progress. By 1941 German engineer Konrad Zuse had developed a
computer, the Z3, to design airplanes and missiles. The Allied forces, however, made greater
strides in developing powerful computers. In 1943, the British completed a secret code-breaking
computer called Colossus to decode German messages. The Colossus's impact on the
development of the computer industry was rather limited for two important reasons. First,
Colossus was not a general-purpose computer; it was only designed to decode secret messages.
Second, the existence of the machine was kept secret until decades after the war.
American efforts produced a broader achievement. Howard H. Aiken (1900-1973), a
Harvard engineer working with IBM, succeeded in producing an all-electronic calculator by
1944. The purpose of the computer was to create ballistic charts for the U.S
It was about half as long as a football field and contained about 500 miles of wiring. The
Harvard-IBM Automatic Sequence Controlled Calculator, or Mark I for short, was an electronic
relay computer. It used electromagnetic signals to move mechanical parts. The machine was
slow (taking 3-5 seconds per calculation) and inflexible (in that sequences of calculations could
not change); but it could perform basic arithmetic as well as more complex equations.
Numerical Integrator and Computer (ENIAC), produced by a partnership between the
U.S. government and the University of Pennsylvania. Consisting of 18,000 vacuum tubes,
70,000 resistors and 5 million soldered joints, the computer was such a massive piece of
machinery that it consumed 160 kilowatts of electrical power, enough energy to dim the lights in
an entire section of Philadelphia. Developed by John Presper Eckert (1919-1995) and John W.
Mauchly (1907-1980), ENIAC, unlike the Colossus and Mark I, was a general-purpose computer
that computed at speeds 1,000 times faster than Mark I.
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In the mid-1940's John von Neumann (1903-1957) joined the University of Pennsylvania
team, initiating concepts in computer design that remained central to computer engineering for
the next 40 years. Von Neumann designed the Electronic Discrete Variable Automatic Computer
(EDVAC) in 1945 with a memory to hold both a stored program as well as data. This "stored
memory" technique as well as the "conditional control transfer," that allowed the computer to be
stopped at any point and then resumed, allowed for greater versatility in computer programming.
The key element to the von Neumann architecture was the central processing unit, which
allowed all computer functions to be coordinated through a single source. In 1951, the UNIVAC
I (Universal Automatic Computer), built by Remington Rand, became one of the first
commercially available computers to take advantage of these advances. Both the U.S. Census
Bureau and General Electric owned UNIVACs. One of UNIVAC's impressive early
achievements was predicting the winner of the 1952 presidential election, Dwight D.
Eisenhower.
First generation computers were characterized by the fact that operating instructions were
made-to-order for the specific task for which the computer was to be used. Each computer had a
different binary-coded program called a machine language that told it how to operate. This made
the computer difficult to program and limited its versatility and speed. Other distinctive features
of first generation computers were the use of vacuum tubes (responsible for their breathtaking
size) and magnetic drums for data storage.
 Second Generation Computers (1956-1963)
By 1948, the invention of the transistor greatly changed the computer's development. The
transistor replaced the large, cumbersome vacuum tube in televisions, radios and computers. As
a result, the size of electronic machinery has been shrinking ever since. The transistor was at
work in the computer by 1956. Coupled with early advances in magnetic-core memory,
transistors led to second generation computers that were smaller, faster, more reliable and more
energy-efficient than their predecessors. The first large-scale machines to take advantage of this
transistor technology were early supercomputers, Stretch by IBM and LARC by Sperry-Rand.
These computers, both developed for atomic energy laboratories, could handle an enormous
amount of data, a capability much in demand by atomic scientists. The machines were costly,
however, and tended to be too powerful for the business sector's computing needs, thereby
limiting their attractiveness. Only two LARCs were ever installed: one in the Lawrence
Radiation Labs in Livermore, California, for which the computer was named (Livermore Atomic
Research Computer) and the other at the U.S. Navy Research and Development Center in
Washington, D.C. Second generation computers replaced machine language with assembly
language, allowing abbreviated programming codes to replace long, difficult binary codes.
Throughout the early 1960's, there were a number of commercially successful second
generation computers used in business, universities, and government from companies such as
Burroughs, Control Data, Honeywell, IBM, Sperry-Rand, and others. These second generation
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computers were also of solid state design, and contained transistors in place of vacuum tubes.
They also contained all the components we associate with the modern day computer: printers,
tape storage, disk storage, memory, operating systems, and stored programs. One important
example was the IBM 1401, which was universally accepted throughout industry, and is
considered by many to be the Model T of the computer industry. By 1965, most large business
routinely processed financial information using second generation computers.
It was the stored program and programming language that gave computers the flexibility
to finally be cost effective and productive for business use. The stored program concept meant
that instructions to run a computer for a specific function (known as a program) were held inside
the computer's memory, and could quickly be replaced by a different set of instructions for a
different function. A computer could print customer invoices and minutes later design products
or calculate paychecks. More sophisticated high-level languages such as COBOL (Common
Business-Oriented Language) and FORTRAN (Formula Translator) came into common use
during this time, and have expanded to the current day. These languages replaced cryptic binary
machine code with words, sentences, and mathematical formulas, making it much easier to
program a computer. New types of careers (programmer, analyst, and computer systems expert)
and the entire software industry began with second generation computers.
 Third Generation Computers (1964-1971)
Though transistors were clearly an improvement over the vacuum tube, they still
generated a great deal of heat, which damaged the computer's sensitive internal parts. The quartz
rock eliminated this problem. Jack Kilby, an engineer with Texas Instruments, developed the
integrated circuit (IC) in 1958. The IC combined three electronic components onto a small
silicon disc, which was made from quartz. Scientists later managed to fit even more components
on a single chip, called a semiconductor. As a result, computers became ever smaller as more
components were squeezed onto the chip. Another third-generation development included the
use of an operating system that allowed machines to run many different programs at once with a
central program that monitored and coordinated the computer's memory.
 Fourth Generation (1971-Present)
After the integrated circuits, the only place to go was down - in size, that is. Large scale
integration (LSI) could fit hundreds of components onto one chip. By the 1980's, very large scale
integration (VLSI) squeezed hundreds of thousands of components onto a chip. Ultra-large scale
integration (ULSI) increased that number into the millions. The ability to fit so much onto an
area about half the size of a U.S. dime helped diminish the size and price of computers. It also
increased their power, efficiency and reliability. The Intel 4004 chip, developed in 1971, took the
integrated circuit one step further by locating all the components of a computer (central
processing unit, memory, and input and output controls) on a minuscule chip. Whereas
previously the integrated circuit had had to be manufactured to fit a special purpose, now one
microprocessor could be manufactured and then programmed to meet any number of demands.
Soon everyday household items such as microwave ovens, television sets and automobiles with
electronic fuel injection incorporated microprocessors.
Such condensed power allowed everyday people to harness a computer's power. They
were no longer developed exclusively for large business or government contracts. By the mid1970's, computer manufacturers sought to bring computers to general consumers. These
minicomputers came complete with user-friendly software packages that offered even nontechnical users an array of applications, most popularly word processing and spreadsheet
programs. Pioneers in this field were Commodore, Radio Shack and Apple Computers. In the
early 1980's, arcade video games such as Pac Man and home video game systems such as the
Atari 2600 ignited consumer interest for more sophisticated, programmable home computers.
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In 1981, IBM introduced its personal computer (PC) for use in the home, office and
schools. The 1980's saw an expansion in computer use in all three arenas as clones of the IBM
PC made the personal computer even more affordable. The number of personal computers in use
more than doubled from 2 million in 1981 to 5.5 million in 1982. Ten years later, 65 million PCs
were being used. Computers continued their trend toward a smaller size, working their way
down from desktop to laptop computers (which could fit inside a briefcase) to palmtop (able to
fit inside a breast pocket). In direct competition with IBM's PC was Apple's Macintosh line,
introduced in 1984. Notable for its user-friendly design, the Macintosh offered an operating
system that allowed users to move screen icons instead of typing instructions. Users controlled
the screen cursor using a mouse, a device that mimicked the movement of one's hand on the
computer screen.
As computers became more widespread in the workplace, new ways to harness their
potential developed. As smaller computers became more powerful, they could be linked together,
or networked, to share memory space, software, information and communicate with each other.
As opposed to a mainframe computer, which was one powerful computer that shared time with
many terminals for many applications, networked computers allowed individual computers to
form electronic co-ops. Using either direct wiring, called a Local Area Network (LAN), or
telephone lines, these networks could reach enormous proportions. A global web of computer
circuitry, the Internet, for example, links computers worldwide into a single network of
information. During the 1992 U.S. presidential election, vice-presidential candidate Al Gore
promised to make the development of this so-called "information superhighway" an
administrative priority. Though the possibilities envisioned by Gore and others for such a large
network are often years (if not decades) away from realization, the most popular use today for
computer networks such as the Internet is electronic mail, or E-mail, which allows users to type
in a computer address and send messages through networked terminals across the office or
across the world.
 Fifth Generation (Present and Beyond)
Defining the fifth generation of computers is somewhat difficult because the field is in its
infancy. The most famous example of a fifth generation computer is the fictional HAL9000 from
Arthur C. Clarke's novel, 2001: A Space Odyssey. HAL performed all of the functions currently
envisioned for real-life fifth generation computers. With artificial intelligence, HAL could reason
well enough to hold conversations with its human operators, use visual input, and learn from its
own experiences. (Unfortunately, HAL was a little too human and had a psychotic breakdown,
commandeering a spaceship and killing most humans on board.)
Though the wayward HAL9000 may be far from the reach of real-life computer
designers, many of its functions are not. Using recent engineering advances, computers are able
to accept spoken word instructions (voice recognition) and imitate human reasoning. The ability
to translate a foreign language is also moderately possible with fifth generation computers. This
feat seemed a simple objective at first, but appeared much more difficult when programmers
realized that human understanding relies as much on context and meaning as it does on the
simple translation of words.
Many advances in the science of computer design and technology are coming together to
enable the creation of fifth-generation computers. Two such engineering advances are parallel
processing, which replaces von Neumann's single central processing unit design with a system
harnessing the power of many CPUs to work as one. Another advance is superconductor
technology, which allows the flow of electricity with little or no resistance, greatly improving the
speed of information flow. Computers today have some attributes of fifth generation computers.
For example, expert systems assist doctors in making diagnoses by applying the problem-solving
steps a doctor might use in assessing a patient's needs. It will take several more years of
development before expert systems are in widespread use.
34
Personal Computers History and Development
The personal computer (PC) has revolutionized business and personal activities and even
the way people talk and think; however, its development has been less of a revolution than an
evolution and convergence of three critical elements - thought, hardware, and software. Although
the PC traces its lineage to the mainframe and minicomputers of the 1950s and 1960s, the
conventional thought that was prevalent during the first thirty years of the computer age saw no
value in a small computer that could be used by individuals.
A PC is a microcomputer, so named because it is smaller than a minicomputer, which in
turn is smaller than a mainframe computer. While early mainframes and their peripheral devices
often took up the floor space of a house, minicomputers are about the size of a refrigerator and
stove. The microcomputer, whose modern development traces back to the early 1970s, and fits
on a desk.
From the start, the creation of the computer was centered around the concept that a single
unit would be used to perform complex calculations with greater speed and accuracy than
humans could achieve.
From the beginning, computers baffled the populous with their capability. In corporate
and government offices and on university campuses, information processing departments
sprouted up to serve the computer. The IBM 701, which was introduced in 1952 as a business
computer, was comprised of several units that could be shipped and connected at a customer's
location, rather than the earlier massive units that had to be assembled on site. In 1953, IBM
began shipping the first mass-produced computer, the IBM 650. IBM introduced the first solidstate (transistorized) computer in 1959, the IBM 7090. Then in 1964, IBM culminated over $1
billion in research when it brought out the System/360 series of computers. Unlike other
mainframes, the System/360 computers were compatible with each other.
By 1960, the computer was king. Companies hired armies of technicians and
programmers to write its operating programs and software, fix it, and allocate the precious
computer time. The capability of the machines was more than a mere mortal could fathom, but
gathering raw data and "keying" it in so the computer could "crunch the numbers" was a
complicated and time-consuming task.
Frustrations abounded, computer errors were called "glitches," and the phrases "garbage
in/garbage out," "It's a computer mistake," and "Sorry, the computer's down and we can't do
anything," were introduced into the lexicon.
On college campuses in the 1960s, students carried bundles of computer cards to and
from class, hoping that their share of the valuable computer time would not be bumped or
allocated to someone else. The term, "Do not fold, spindle or mutilate," was coined so people
wouldn't disable the process of feeding the punched computer cards into punch card readers,
where the intricate patterns of holes were decoded.
The computer mystique was reinforced in people every time they heard of some new
accomplishment. In 1961, a computer calculated the value of pi to 100,000 decimal places. A
computer could play checkers, and in 1967 a chess playing computer program was made an
honorary member of the United States Chess Federation. Banks began printing checks with
magnetic ink so they could be processed by the computers.
Until 1971, nobody even thought of a computer as anything but a big, fast, electronic
brain that resided in a climate-controlled room and consumed data and electricity in massive
quantities.
In 1971, an Intel 4004 chip containing 4004 transistors was programmed to perform
complex mathematical calculations; the hand-held calculator was born. Suddenly, scientists and
engineers could carry the computational power of a computer with them to job sites, classrooms,
and laboratories; but the hand-held calculator, like the ENIAC before it, was not yet a computer.
The microprocessor was developed by Robert Noyce, the founder of Intel and one of the
inventors of the integrated circuit, and brought with it a change in the way people worked.
35
Exercise 1
Decide if the sentences are true (T) or false (F).
1. Computers have not infiltrated every aspect of our society. ______
2. The personal computer (PC) has revolutionized business and personal activities and
even the way people talk and think; ______
3. Defining the fifth generation of computers is somewhat difficult because the field is
in its infancy._____
4. In 1697, a German mathematician and philosopher, Gottfried Wilhem von Leibniz
(1646-1716), improved the Pascaline by creating a machine that could also multiply.
_____
5. The real beginnings of computers as we know them today, however, lay with an
English naturalist professor, Charles Babbage (1791-1871). ___
6. In the 1980's, the U.S. Defense Department named a programming language ADA.
_____
7. With the onset of the Second World War, governments sought to develop computers
to exploit their potential strategic importance. _____
8. American efforts produced a broader achievement. _____
9. In the mid-1940's John von Neumann (1903-1957) joined the University of
Pennsylvania team, initiating concepts in computer design that remained central to
computer engineering for the next 40 years. ______
10. By 1958, the invention of the transistor greatly changed the computer's development.
____
Exercise 2
Answer the following questions
What was the real computers’ beginning?
Who was the first computers’ inventor? When did he invent the first computer?
How many variables could be stored on a single card?
What was the influence of the Second World War to the computers’ development?
What was the computer’s purpose for the U.S. Navy?
How many resistors, vacuum tubes and solders joints were in the first computers in
the USA?
7. What was the second step in the computers’ development? Give the extended answer.
8. What was the program and programming language like in 1965?
9. What is the integrated circuit and what it’s purpose?
10. Define the fifth generation of computers?
1.
2.
3.
4.
5.
6.
Exercise 3
Complete each gap with one word, using the words in the chart.
Activities, development, prevalent, revolutionized, elements, evolution, lineage, hardware,
minicomputers, age, individuals.
Personal Computers History and Development
The personal computer (PC) has_____________ business and personal___________ and
even the way people talk and think; however, its_________thas been less of a revolution than
36
an________ and convergence of three critical ______-- thought,_______ , and software.
Although the PC traces its _______to the mainframe and_______ of the 1950s and 1960s, the
conventional thought that was________ during the first thirty years of the computer_______ saw
no value in a small computer that could be used by___________.
Exercise 4
Write dialogues to the following themes:




Computers’ Inventors
Five Computers’ Generations
Personal Computers’ History and Development
New Technologies and Ideas
Exercise 5
Give definitions to these words and word combinations
Transaction, centerpiece, equation, to calculate, integrated circuit, to solve, electronic
circuit, data, computer program, transistor, capability, high-level language, single chip, central
processing unit, software, hardware, magnetic ink.
4. Theme: Surf the Net
1.
Lead-in
Match the words/phrases (1-6) to the definitions (a-f)
2. a) Mark the statements as T (true) or F (false).
The Internet was started in 1990. F
The Internet links computers.___
To visit a web site, you simply enter the telephone number. ___
The main use of the Internet is to find mistakes.___
Using the Internet is getting more expensive.___
b) Then correct the false statements, as in the example.
The Internet wasn’t started in 1990. It was stalled in 1968.
3. Read the information leaflet about the Internet, and match the questions (a-J) to the
numbered spaces (1-6), as in the example. Then, explain the words in bold.
The Internet: FAQs
(Frequently Asked Questions)
The Internet is without doubt one of the most important inventions in history. It was
started in 1968 by the US government, but at first it was used mainly by scientists. Since 1990,
when the World Wide Web was created, it has changed the world, and its uses are growing
every day.
37
1 (a)... What exactly is the Internet?.............................................................................................
The Internet is a network (several networks, in fact) of millions of computers around the
world, connected by phone lines, satellite or cable, so that all the computers on the net can
exchange information with each other.
2 ………………………….……………………………………………………………………..
Not quite. The Internet links computers, and the World WideWeb is a system which links
the information stored inside these computers.
3 ……………………………………………………………………………….…………………
A company or organisation stores its information in electronic documents on one of the
Internet computers, somewhere in the world. This computer space - the company’s web site - has
an address, in the same way that every telephone has a number. To visit a web site, you simply
enter the address. Your computer is connected to the web site, a document is downloaded, and
a page appears on your computer screen.
4 …………………………………………………………………………………………………
When you visit a web site looking for information, some words on the page may be
underlined, showing that there is more information about the subject in another document. If
you click on one of these words, the Web automatically connects your computer to a new
document or web site, even if this is stored thousands of kilometers away. You’re surfing the
net!
5 …………………………………………………………………..…………………………….
The main use of the Internet is to find information - for yours schoolwork or job, or just
to find out more about your hobbies, sports or current events. You can also use the Internet to
read newspapers and magazines, play games, plan your holiday or buy things from your
favourite shop. E-mail makes it possible to send electronic messages anywhere in the world in
seconds, and you can use the Internet to ‘chat’ with people and make new friends.
6 …………………………………………………………………..…………...........................
If you don’t already use the Internet, all you need to get started is a computer, a modem
and a phone line. Using the Internet is getting cheaper and easier all the time. Are you ready to
surf the Net? There’s a whole exciting Internet world out there waiting for you!
a
What exactly is the Internet?
b
What do I need in order to use the Internet?
c
How do I “surf the Net”?
d
That’s the same thing as the Web, isn’t it?
e
What can I use the Internet for?
f
What is a web site, and how do I visit one?
Vocabulary
1. a) Match the items in the two columns to form phrases, as in the example.
b) Read the on-line dialogues and fill in the phrases from above. There is one phrase that
you do not need.
Wolf > Are you there, Gail?
Gail > Hi Wolf — yes I’m here — did you get my
1)……………..…………………………………………………………………………...?
Wolf > Yeah, I got it just now. Sorry I didn’t have the chance to check my mail earlier — I was
too busy 2)…………………………………………………………………………………………
38
Gail > Did you find any good
3)………….....................................................................................?
Wolf > Well, I found a great site called Music Mania. You can 4)………………………………
on all the best groups. You can even download songs and video clips!
Flyer > Are you on-line, Aries?
Aries > Hi Flyer - what have you been doing?
Flyer > I’ve been catching up on 5)…………………………on the net. What about you?
Aries > I’ve been doing boring housework. My 6)………..………… ………………was really
dirty. At least I can see what you’ re saying now!
Flyer > Yuck! Housework! Surfing the net is much more fun, isn’t it?
2. How do you print something from the net?
Put the instructions in the correct order.
a
Wait for the document to be downloaded and the page to appear on your screen.
b
Decide which part of the document you want to copy.
c
Click on the print symbol to print your selection.
d
Enter the address of the web site.
e
Wait for your computer to be connected to the web site.
3. Cross the odd word out. Give reasons, as in the example.
1 modem, radio, mouse, keyboard (the others are used with computers)
2 go skiing, join a newsgroup, make new friends, listen to music
3 send e-mail, post a letter, make a phone call, download a document
4 but, however, in conclusion, on the other hand
5 advantages, disadvantages, pros, good points
Language Development
4. Fill in the words from the list, then make sentences using the completed phrases.
web, surf, exchange, computer, change, get, electronic, enter, current, phone, important
1 ............. inventions
7 to the………. address
2 to ……… the world
8 a ……… …….screen
3 ……………….lines
9 to ………………the net
4 to …… information
10 ……………….. events
5 …………documents
11 to…………started
6 a ………… .……site
5. Fill in the correct prepositions, then make sentences using the completed phrases.
1 ……….. doubt; 2 exchange information ………… each other; 3 ………. the world;
4 appear ……….. the screen; 5 …….the page; 6 information ………. sth; 7 to click …………
sth; 8 waiting ……….. sb; 9 stored ……… a computer; 10 find out …….… sth
6. Writing
Read the text again, then use the notes below to write about the Internet.
39
Internet Internet
=
network of computers around the world
You need:
computer, modem and phone line
To surf the
Net, you:
enter a web site address, connected to the web site,
download document, page appears on screen, click
on underlined words, connected to new
documents/web sites
information
for
schoolwork/job/
You can use it find
hobbies/sports/current
events,
read
to:
newspapers/magazines, play games, plan holidays,
buy things, send electronic messages (e-mail), ‘chat’
with people, make new friends
Theme: 5. Grammar: Direct and Indirect Speech
• Grammar: Reported Instructions
7. Study the rule and the examples, then say how reported instructions differ from
reported questions.
8. Last Monday Jeff had his fifth lesson on how to use the Internet. His instructor gave him
some tips. Put the tips into reported speech.
40
1 ……………………………………………………………………….
2……………………………………………………………………….
3……………………………………………………………………….
4……………………………………………………………………….
5.……………………………………………………………………….
6………………………………………………………………………
9. Rewrite the sentences in reported speech, as in the example.
1. ‘Who sent the e-mail message?’ Sally asked John.
Sally asked John who had sent the e-mail message.
2. ‘He has called twice,’ she said.
……………………………………………………………………………..
3. ‘Where does he live?’ Sue asked.
……………………………………………………………………………..
4. ‘He missed the bus’, Claire said.
……………………………………………………………………………..
5. ‘I see you on Monday,’ Bob said to Lyn.
……………………………………………………………………………..
6. ‘I can’t help you,’ Karen said to Mary.
……………………………………………………………………………..
10. Read the e-mail message and answer the questions. Then, turn the
reported instructions into direct speech.
To: frank@notor.co.uk
From: john@preston.com
Date: 13.03.2013
Subject: Tom Billings-new offices
Dear Frank,
Just a quick note to check that I gave Tom Billings the correct instructions
concerning the new offices.
I told him to make sure there are phone lines in each office. I asked him to order
computers for all the offices. I also told him to finish the decorating by next week.
Hope I didn’t forget by next week.
Karren Briggs
1. Who sent the message?
2. What is it about?
3. Are the layout and style the same as for a letter?
Use the prompts below to write questions with question tags, as in the example.
- you/spend/a lot of your free time watching videos
- you/have got/a lot of fans
- your/fan-club web site/be/one of the most
- visited web sites on the net
- you/not like/playing computer games
- you/get engaged to/the singer Dee Brown last month
41
Laura: I’d like to welcome Chris Newton to the studio this morning. Your fans want to know
all about what you do in your free time.1) ... You spend a lot of your free time watching
videos, don’t you?...
Chris: Yes, I do. I prefer the cinema but I get followed by fans everywhere I go now.
Laura: 2)………………………………………………………………………………….…………
………………………………………………………………………………………………
Chris: Yes, I have. Sometimes I can’t believe how much mail I get!
Laura:3)…………………………….………………….………………………………….………
Chris: Yes, it is. I love reading e-mail from my fans.
Laura: 4)………………..……………………………………..…………………………………….
Chris: No, that’s not true. I love playing computer games. It’s great fun.
Laura: 5)……………………………………….…………………………………………………
Chris: I’m sorry. I don’t want to talk about Dee. That’s private.
Laura: Oh ... okay. Well, thanks for coming into the studio to talk to us. Now, let’s hear your
latest song ...
12. The students in Mr Penny’s class are having a test. Look at his instructions and report
them, as in the example.
1 Mr Penny told them not to talk during the test
2 ……………………………………………………………………………………………………
3 ……………………………………………………………………………………………………
4 ……………………………………………………………………………………………………
5 ……………………………………………………………………………………………………
6 ……………………………………………………………………………………………………
7 ……………………………………………………………………………………………………
8 ……………………………………………………………………………………………………
13. Read the reported conversation, then complete the actual conversation using direct
speech.
42
I asked Nancy where she lived, and she told me that she lived in Perth, Australia. I also
asked her how old she was and she told me that she was thirteen years old. When I asked her if
she had any hobbies, she told me that she had a lot of hobbies. She added that she enjoyed
swimming, playing volleyball and that she also liked collecting stamps. I told her that I collected
stamps too, and that I had over 100 stamps from many different countries. I asked her how many
she had and she told me that she had about 220 from all over the world. I asked her if she had
many friends and she told me that she did, but only two of them were her best friends. Their
names are Amy and Ellen.
Jenny: Where do you live?
Nancy: I 1) ………………………..……………………………………………... Perth, Australia.
Jenny: How 2) ………………………………………………………………………………….... ?
Nancy: I 3)……………………………………………. …………………………………………..
Jenny: 4) ………………………………… ………………………………………….any hobbies?
Nancy: 5) ……………… hobbies. I 6) ……………...……………………………………………
I also 7) ……...……………………………………………………………………………
Jenny: 8) …………, too! I 9) ……………. ………………………………………..from different
countries. How 10) ………………………………………………………………………. ?
Nancy: I 11) …………............................................................................... from all over the world.
Jenny: 12) …………………………………………………………………………. many friends?
Nancy: Yes, 13) ……………. ……………….but 14) …………………. ………………………..
Their names are Amy and Ellen.
Writing (a For-and-against Essay)
14. Match the viewpoints in column A to their explanations in column B. Then, read the
topic sentences in the box below and decide which a) introduces the main topic, b)
introduces points for, c) introduces points against, and d) sums up the topic.
A
B
1 Computers can do certain tasks much faster
A As a result, employers can reduce their
than people.
workers’ workload and increase their wages.
2 Computers don’t make mistakes.
B This could lead to high unemployment.
3 Computers don’t need to be paid for the work C This means that they can do the timethey do.
consuming tasks while workers concentrate on
other tasks.
4 In many industries, computers may replace
D This means that they can’t judge people’s
people altogether.
characters or help people with emotional
problems.
5 Computers do not have personalities or
E Therefore they can be used to help workers
feelings.
such as air- traffic controllers or surgeons
whose work is dangerous or demanding.
Topic Sentences
1On the other hand, using computers in the workplace also has disadvantages.
2 In the last few years computers have become a part of almost everybody’s everyday lives —
especially in the workplace.
3 In conclusion, I believe that using computers in the workplace has both positive and negative
points.
4 Using computers in the workplace offers many advantages.
43
15 Use the information from Ex. 14 to write a for-and-against essay entitled “The
Advantages and Disadvantages of Computers in the Workplace” (100 - 160 words). Use the
article in Ex. 13 as a model.
6.Theme: The Web
In this theme you will
read a factfile, a questionnaire and a web page
listen to a survey; take phone messages
talk about the Internet; practise making phone calls
write a page for the Internet
learn more about conditional sentences
Warm-up
1 Use the Mini-dictionary to complete the factfile below with the Key Words.
KEYWORDS:
bookmarks, browser, download, favourites, Internet, links, online, search engine, website,
World Wide Web
2. Work in pairs. Are these statements true (T) or false (F)?
1 ___ There are more Internet users in Europe than in North America.
2 ___ Americans send more than four billion emails every year.
3 ___ Search engines like Google can find hundreds of thousands of websites in less than a
second.
4 ____ In 2000, over nine million people watched one of Madonna's concerts 'live' on the
Internet.
5 ___ Computers operate better when they are cool because they conduct electricity more
efficiently.
3. Work in pairs. Write what you have tried or would like to try on the Internet.
Example I'd tike to send emails to my cousins in the USA.
 chat online
 send emails
 find information for your studies
 find information about entertainment/travel
 listen to and/or download music
 shop, e.g. for videos, CDs, clothes
 read about your interests
 practise your English
 FACTFILE: The Internet
 The 1 __________ is an international network of computers – it includes electronic mail
(email), the World Wide Web (www), discussion groups and online chatting.
 To go 2 _________ , you need a 3 ___________, such as Netscape Navigator or Microsoft
Internet Explorer. These programs let you see web pages and 4 ___________ information
onto your computer.
 The 5 __________ is a collection of web pages. Each page has6 __________ to other
pages which you can get by clicking on words or pictures.
 A 7 _________ , or web page, is a document available on the World Wide Web.
 To look for information, type key words into a 8 __________ , such as Google, which
gives you a list of useful websites.
 If you find a good website, you can save it for future reference - put it in your 9 ________
or 10 __________ .
44
Online
Before you start
1. Match the Key Words with the things (1-5) in the
photo.
KEY WORDS: sources of information
a CD-ROM encyclopedia, a dictionary, an
encyclopedia, the Internet, a reference book on a
special topic
2 What problems can people have when they look
for information on the Net? What problems have
you had?
3 Answer the questionnaire.
Are You An Online Student?
Your English group is doing a project on Native
American folk dancing in Alaska. You have to
prepare an article. So ...
1. Do you try to find information: ___
a) on the Internet? b) in an encyclopedia? c) from other reference books?
2. You have about 15 minutes before the end of the lesson. Do you: ___
a) go to the school library to find some information?
b) make a list of questions you want to find answers to?
c) write down what you already know?
3. You want to start looking for information on the
Internet using a search engine (like Google). What key
words do you type in and search for? ___
a) Native Americans b) folk dances Alaska c) folk dances
4. You find a really good website. Do you: ___
a) try to remember the address?
b) write the address in your notebook?
c) put it in your bookmarks or favourites?
5. You find a website with the answer to your dreams a short article called 'Native American folk dances in
Alaska'. Do you: ___
a) try to write a summary of the article in your own words?
b) print it out and use it to answer the questions on your list?
c) copy it, put your name at the top and give it to your teacher?
6.Warm-up
Find 14 words related to the Internet.
w e b s і
t
e
f
a
o і
o e w x m e
d
r с h a t
r a
z
u
1 m с r к e і
с
t
d o d с o n l
1
n
n
o
с
r
к
e
b
b
o
o
к
f
a
v
o
u
y
m
r
w y
b
h
l
e
n
і
s
i
d
te
e
w
r
n
e
t)
n
o
t
w
e
n
r
l
n
o
e
a
d w
j o
a
r
і
t
e
h
n
l
g
і
n
n
e
к
t
s
t
d
j
w
os
o r
e d
к
s
e
s
45
e
b
e
a
s
і
n
e
l
с
b
o
r
m
o
p
w s
u t
e
e
r
r
7.Write example sentences in your notebook with the words from Exercise 6.
The Internet is яп international computer network. I use the Internet three times a week..
_____________________________________________________________________________
_____________________________________________________________________________
_____________________________________________________________________________
7. Theme: Grammar: First and Second Conditional
Presentation
1. Read the sentences (1-4) and complete the table with the tenses used. What does'd stand
for in sentences 2 and 3?
1. If I didn't use the Net, I wouldn't find information for most of my school projects.
2. If I knew anything about folk dancing, I'd write it all down.
3. If there were only fifteen minutes left, I'd write a list of questions.
4. If I copied it, I'm sure the teacher would know.
Condition
Consequence
if + ________
____________
2. Read the sentences in Exercise 1 again. What is he talking about?
a situations that are real or will probably happen
b imaginary or unlikely situations
Complete the rule with two of these words:
present, past, future
We use the Second Conditional to talk about_________ situations that are unlikely
or__________ situations that are imaginary or unreal.
Practice
3. Who could say these things? Choose a or b.
1 If I had the money, I would go on holiday to the Caribbean.
a a student
b a millionaire
2 If I lived in London, I could visit the Science Museum every month.
a a Londoner
b a New Yorker
4. Use the cues below to write Second Conditional sentences.
Example
1 If I didn't have a computer, I wouldn't use the Internet.
1 if/not have computer/not use the Internet
2 if/win lottery/buy a new computer
3 if/play computer games/not be a good student
4 go to Tibet/if/have money
5 if/be a computer expert/earn a lot of money
6 make new friends/if/use Internet
5. Write sentences using the Second Conditional based on these imaginary present
situations.
Example
1 If I didn't like cooking, I wouldn't work as a chef in a restaurant.
1 I like cooking so I work as a chef in a restaurant.
If___________________________________________
2 I don't think I'll win the race so I probably won't get the prize.
If___________________________________________
46
3 There is very little time left so we can't go on foot.
If___________________________________________
4 I'm very tall so I play in the school basketball team.
If______________________________________
5 Imagine we go on an expedition to Mount Everest - everyone will admire us.
If___________________________________________
6. Which place in the world would you like to go to? Write a Second Conditional sentence
about the places below and three other places of your choice.
Example
If I went to the Grand Canyon, I would take a canoe trip down the Colorado River.
•Grand Canyon • Paris • China • New York• the Amazon jungle • Hollywood
7. Imagine what would happen if these things came true. Make two or three conditional
sentences for each situation.
Example
1 If all the telephone lines in the world went dead, companies would lose a lot of money. People
wouldn't be able to call the emergency services.
I would miss talking to my friends on the phone.
1 All the telephone lines in the world go dead.
2 There is no Internet.
3 All the computers in the world break down.
4 Everybody speaks the same language.
5 You don't have to go to school.
6 Someone invents a time machine.
8 SECOND CONDITIONAL
 Second Conditional for present situations that are not real.
Write possible sentences using the table.
If I had the money, I would buy
on a world tour.
If I was President of
my country, I
wouldn't go
school holidays longer.
make
a big car.
live
school holidays shorter.
have
here.
in the Caribbean.
to the Caribbean.
more jobs for people.
more festivals.
1 If I was President of my country, I would make school holidays longer
2_______________________________________________________________________
3_______________________________________________________________________
4_______________________________________________________________________
5_______________________________________________________________________
6_______________________________________________________________________
7_______________________________________________________________________
8_______________________________________________________________________
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Now finish these sentences in any way you want.
If I was President of my country,____________________________________________________
________________________________________________________________________
if I had more money,_______________________________________________________________
_______________________________________________________________________________
 Write sentences. Use the Second Conditional.
1. if/not be/any television/people/talk more
if there wasn’t any television, people would talk, more.
2 if/I/live in the USA/I/not live/in one of the big cities
________________________________________________________________________
3 if/it/snow/every day in winter/I/go skiing/as often as possible
________________________________________________________________________
4 I/visit/the Great Wall/if/I/go/to China
________________________________________________________________________
5 If/I/become famous/I/not move/to a bigger house
________________________________________________________________________
6 We/not be happy/if/we/not have/any friends
 First and Second Conditional.
Match the sentence beginning 1-8 with the ends (a-h)
1 If I see Mark,
2 If they have enough money next month,
3 If I watched a horror film on my own at night,
4 If we go out for a meal,
5 If I have a coffee before I go to bed,
6 If they had more money,
7 If we went to that restaurant,
8 If you phoned Simon,
a I wouldn't be able to sleep after.
b they would buy a new car.
c I'll tell him you phoned.
d what would you say to him?
e we'll go to the new Italian restaurant.
f I'd have pasta or pizza. I love them both!
g they'll go on holiday to China.
h I won't be able to sleep, I'll be wide awake.
1 c 2 ___ 3 ___ 4 ___5 ___ 6 ___ 7 ___ 8 ___
 First or Second Conditional?
Write sentences with the correct form of the verbs. Use the First or Second conditional.
1. I live in Scotland. If I lived (live) in France, I would learn (learn) French.
2. If I _____
(be) you, I _______ (not go) to the party. I really don't think it's a good
idea.
3. I usually see John in the afternoon. I __________ (give) him your message if I____ (see)
him later.
4. Don't worry. I __________(help) you with your chemistry homework if you ________(not
understand) it. I'm good at chemistry.
5. I _______(buy) a new computer if I ________ (have) enough money. Unfortunately I've
only got 50!
6. I'm saving up at the moment. If I_______ (have) enough money at the end of the year, I
(buy) a CD player.
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7. The weather's been very good recently. If it ________ (be) good at the weekend, we (go) to
the mountains.
8. I _______ (do) more sport if I ________ (have) more free time, but I'm extremely busy at
the moment.
 Write a First Conditional and a Second Conditional sentence about each subject.
Computers
1. do homework on the computer/quicker
If you do your homework on the computer, it will be quicker_____________________________
_____________________________________________________________________________
2. life very different/not have computers
Life would be very different if we didn’t have computers.______________________________
_____________________________________________________________________________
Football
3. like football/enjoy watching my team
_____________________________________________________________________________
_____________________________________________________________________________
4. Scotland win the World Cup/be very happy
_____________________________________________________________________________
_____________________________________________________________________________
Jobs
5. work hard at school/get good job
_____________________________________________________________________________
_____________________________________________________________________________
6. not be a doctor/like to be a teacher
_____________________________________________________________________________
_____________________________________________________________________________
9. Personalisation.
Imagine your ideal future life. Think about your home, job, partner, family, etc. Write
conditional sentences to explain why you would like this kind of life. Example
I'd like to live in Africa and work as a doctor. If I was a doctor in Africa, I would help a lot of
people.
10. In pairs, write your choices.
Example
I'd like to be an astronaut, because if I were an astronaut, I would...
11. Translate the following sentences into Ukrainian. Pay attention into sequence of tenses.
1. I thought that he finished his work at five every day.
2. I thought that he had finished his work.
3. She supposed that they always came in time.
4. She supposed that they had come in time.
5. He hoped that she studied well.
6. He hoped that she had studied well at school.
7. We knew that he .was ill.
8. We knew that he had been ill.
9. I did not know when they left home.
10. I did not know when they had left home.
11. He said his father was a pilot.
12. He said his father had been a pilot.
13. They were sure she wrote letters to her granny.
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14. They were sure she had written a letter to her granny.
15. She said that she would visit us in a week.
16. Our teacher said we would be writing the test at two o’clock.
12. Put these sentences in the Past Simple. Pay attention into the changes in the
subordinate
clause.
1. She says she likes roses.
2. She says he has already written the article.
3. They say they will come to see us next Friday.
4. She says she is glad to see me.
5. We do not know when he comes home.
6. Ann is sure we will arrive on Friday.
7. Peter thinks his friend has just returned home.
8. My teacher believes I will succeed in my studying.
9. I know he always gets up early.
10. We expect Dorothy will join us in the evening.
11. He says he has left his bicycle in the yard.
12. I suppose they met in the street.
13.
Put these sentences in the Past Simple. Pay attention into the changes in the
subordinate
clause.
1. Christy says he will tell you the truth.
2. Nobody knows what she means.
3. We think that he is joking.
4. John says he knows how I feel. 1
5. Harry doesn’t know when his cousin will come.
6. I can’t believe she has done it.
7. He thinks they are driving to the country.
8. She is sure^ we will be glad to meet her.
9. I don’t know where she is.
10. I don’t think they will be having breakfast so early.
11. We hope they have noticed us.'
12. He doesn’t suppose she speaks so much.
13. She says she will let me know when they come.
14. I think he came in a taxi.
15. They are sure we will be waiting for them in the bar.
14. Open the brackets using the sequence of tenses.
1. She realized that nobody (will come/would come).
2. We understood that she (sees/saw) nothing.
3. He said he (will arrive/would arrive) in some days.
4. My mother was sure I already (have come/had come).
5. I didn’t know they (are/were) in the room.
6. We supposed the rain (will stop/would stop) in some hours;
7. He said he never (has been/had been) to Kyiv.
8. We wanted to know who (is singing/was singing) in the next room.
9. I always thought he (is/was) a brave man.
10. When I saw him, he (is working/was working).
11. We know she always (comes/came) in time.
12. They thought he (will have finished/would have finished) his work by the evening.
13. She said she (has/had) a terrible headache.
14. We supposed they (will send/would send) us the documents.
50
15. He said he (has not seen/had not seen) us for ages.
15. Open the brackets using the sequence of tenses.
1. Her brother said he never (to see) this film before. ;
2. He came home and listened: his son (to play) the piano.
3. They didn’t worry too much because they (to lock) the door.
4. I asked her when she (to give) me this book to read.
5. We wanted to know if they (to enjoy) the meal.
6. She supposed she (to like) the hotel.
7. 7.1 am afraid they (not to come) yet.
8. He wanted to know if the station (to be) away.
9. Eric doesn’t know who (to phone) him at five o’clock.
10. He admitted he {not to be) here for weeks.
11. She apologies she (to arrive) so late.
12. Jean promised she never (to speak) to me again.
13. Andy said he just (to buy) a new car.
14. My mother decided that she never (to drink) coffee late at night.
15. I hear you already (to find) a new job.
16. We were sure our children (to sleep).
17. I didn’t think they still (to discuss) this problem.
18. It is remarkable that you (to come) at last.
19. My doctor thinks I (to be) allergic to pineapples.
20. Sophia knew her aunt (to be) glad to visit her in two days.
16. Open the brackets using the sequence of tenses.
1. When I opened the window, I saw the sun (to shine).
2. We are sure Simon (to marry) her some time later.
3. He can’t remember where he (to put) his glasses.
4. George thought the restaurant (to be) expensive.
5. She was disappointed that she (not to get) the job.
6. I didn’t understand why they (to destroy) their relationship.
7. He is not sure they (to find) their way in the darkness.
8. Jane asked me if I (to invite) Ann to the party.
9. People say that he always (to be) very rich.
10. She said she (to wait) for me since seven o’clock.
11. They thought I (to give) them my telephone number.
12. I am afraid I (not can) answer you question.
13. We wanted to know what (to happen) to John.
14. George thought he (can) repair the car himself.,
15. She is very upset: she (to break) her watch, r
16. Bill said he (to feel) ill.
H:
17. We thought she still (to be) in hospital.
18. I knew he (to pass) his examination at that time.
19. My cousin promised he (to visit) me in a week.
20. We didn’t know they (to be) tired.
17. Translate into English. Pat attention into sequence of tenses.
1. Я думав, що вона хворіє.
2. Ми сподівались, що він прийде вчасно.
3. Я не знав, що його сестра вивчає англійську мову.
4. Він впевнений, що закінчить роботу до вечора.
5. Вона сказала, що не хоче йти на прогулянку.
51
6. Ми хотіли знати, коли вона прийшла.
7. Мій друг каже, що вже прочитав цю статтю..
8. Я не знав, що він зайнятий і не може мені допомогти.
9. Ніхто не хотів вірити, що він сказав правду.
10. Вона сподівається, що я не працюватиму в неділю.
11. Ми побачили, що діти грають у футбол.
12. Він сказав, що його мати лікар.
18. Form from these sentences complex object sentences.
1. They are working in the garden. (We were sure).
2. I have never been to Paris. (I told).
3. They have been waiting for him for ten minutes. (He didn’t know).
4. Tim hasn’t written for them for ages. (She knew).
5. Kath will not see us. (My mother wrote).
6. He is going to the park. (He told me).
7. They are skating. (I supposed).
8. Somebody has stolen his purse. (He did not notice).
9. Sophie is a very clever girl. (Everybody knew).
10. He doesn’t agree. (He told).
11. She haven’t done her homework. (She said).
12. I don’t like going to parties. (I told them).
13. She doesn’t know how much "the dress cost. (Mary told me).
14. We will come again next year. (We wrote them).
15. I am washing the car. (I told him).
16. He has already seen this play. (He didn’t tell us).
17. She is not feeling very well. (She told the doctor).
18. He is translating the article. (I saw).
19. She will talk to Susan. (She promised).
20. He can not swim. (I didn’t suppose).
19. Translate into English using sequence of tenses.
1. Вона сказала, що буде рада побачити нас знов.
2. Він сказав, що знає, як я себе почуваю.
3. Я сказав, що він щойно повернувся з відрядження.
4. Ми не помітили, як діти вийшли з кімнати.
5. Вона пообіцяла, що надішле нам листівку.
6. Він не хотів вірити, що вони не розуміють його.
7. Він не сказав, що не любить ходити в театр.
8. Ми сподівались, що він уже повернувся додому.
9. Вона сказала, що живе в Києві уже двадцять років.
10. Мій брат сказав, що не згодний зі мною.
11. Ми хотіли знати, де він і що він робить в цей час.
12. Всі знали, що вона поїде у відрядження, але не знали коли вона повернеться.
13. Я не міг зрозуміти, чому він не прийшов. Я подумав, що він хворий.
14. Мама сказала, що вона повернеться до сьомої вечора.
15. Ніхто з учнів не знав, що він такий сильний.
16. Він сказав, що зайнятий, що він працює над доповіддю.
17. Моя сестра сказала, що ніколи не зустрічала цієї жінки раніше і нічого про неї не
чула.
18. Ми були дуже раді, що вони не заблудилися в незнайомому місці і прийшли
вчасно.
19. Всі думали, що лекція почнеться о десятій.
52
20. Ми не сподівались, що побачимо його знову.
20. Translate into English using sequence of tenses.
1. Він сподівався, що проведе наступне літо біля моря.
2. Мама сказала, що вона хоче залишитись дома.
3. Я знав, що нічого особливого з ним не трапилось.
4. Нам здавалось, що вона сміється над нами.
5. Всі розуміли, що він помиляється, але ніхто не наважувався сказати йому про це.
6. Вона сказала, що чекає свою подругу вже чверть години.
7. Вони спитали мене, що я робитиму в неділю.
8. Я не був впевнений в тому, що він поговорив з батьками.
9. Тренер пояснив нам, що це дуже небезпечний вид спорту.
10. Моя двоюрідна сестра пообіцяла мені, що прийде до мене в гості через тиждень.
11. Батько сказав, що не знає чи дзвонив мені хто- небудь, тому що,його не було
вдома.
12. Вона сказала, що не хоче кави, що вона поп’є чаю.
13. Він сповістив нам, що делегація прибуде сюди приблизно о третій.
14. Я хотів знати, які мови вони вивчають і чи розмовляють вони англійською мовою.
15. Він зрозумів, що втратив гарну нагоду заробити трохи грошей.
16. Вона хвилювалась, тому що не знала, чи сподобаються дітям її подарунки.
17. Вони сказали, що економічна ситуація гірша, ніж вони припускали.
18. Ми сподівались, що це буде найцікавіша зустріч.
19. Мій брат написав мені, що він вступив до університету.
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Література
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2. Dinos Demetriades, Information Technology, Oxford University Press, 2012. – 39 c.
Longman, 2006. - 144 с.
3. Kathy Gude with Gayne Wildman – Matrix Intermediate Student′s Book Oxford University
Press, 2008. – 152 с.
4. Lindsay White, Engineering Workshop, Oxford University Press, 2011. – 39 c.
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7. Tom Hutchinson. Project English 3, Oxford University Press, 2012. – 120 c.
8. Dr. Keith Brown. Oxford Guide to British and American Culture. - Oxford University Press,
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с.
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Київ: Києво-Могилянська академія, 2004. - 429с.
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31. Байбакова І. М. Getting into English. - Львів: Бескид Біт, 2008. – 251 с.
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NOTES
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55
Навчально-методичне видання
Іноземна мова (за професійним спрямуванням)
Методичні рекомендації до виконання самостійної роботи для студентів ІІІ курсу
спеціальності 5.0501201 «ОБСЛУГОВУВАННЯ КОМП’ЮТЕРНИХ СИСТЕМ І МЕРЕЖ»
денної форми навчання.
Комп’ютерний набір і верстка:
Редактор:
Семенюк Я.О.
Гордіюк О.С.
Підписано по друку ________________ 2013. Форма 60х84/16. Папір офіс.
Гарн. Таймс. Ум. друк. арк. 3,26 Обл.-вид. арк. 3,0
Тираж 100 прим. Зам.141
Редакційно-видавничий відділ
Луцького національного технічного університету
43018 м. Луцьк, вул.. Львівська 75
Друк – РВВ ЛНТУ
56