2. Answer the questions to the text.

1. What is an operating system?

2. What does application programs usually to function?

2. Where can operating systems be found?

2. Give examples of popular modern operating systems?

2. What is a real-time operating system?

2. What is the main objective of real-time operating systems?

2. What does a multi-user operating system allow?

2. What are embedded operating systems designed for?

3. Translate the following words and word combinations from English into Russian. Use them in the sentences of your own.

Computer hardware and software, application programs, time-sharing operating systems, accounting software, input and output, a real-time operating system, deterministic nature of behavior, running program, embedded operating systems, cloud computing context, template.

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4. Translate the following words and word combinations from Russian into English. Use them in the sentences of your own.

Распределение памяти, встроенная вычислительная система, программные ресурсы, системное программное обеспечение, прикладные программы, функционировать, программное обеспечение для бухгалтерского учета, операционная система, работающая в режиме распределения времени, операционная система реального времени, запоминающее устройство сверх большой емкости, время процессора, код прикладной программы (код приложения), промежуточное звено, игровая приставка, событийно-управляемая система, прерывание по таймеру, однозначная система, вытесняющая многозадачность, шаблонная обработка, с наименьшей автономией, «облачная» вычислительная среда, хранилища сервера, многозадачность.

5. Decide if the sentences are true or false.

1. An operating system (OS) is hardware that manages computer hardware and software resources and provides common services for computer programs.

2. Application programs do not usually require an operating system to

function.

3. An event-driven system doesn't switch between tasks based on their priorities or external events while time-sharing operating systems switch tasks based on clock interrupts.

4. A multi-user operating system allows multiple users to access a computer system at the same time.

5. Distributed computations are not carried out on more than one

machine.

4. Complete the following sentences. Use the words from the texts.

1. The operating system is an	component of the system software
in a computer system.

2. programs usually require an operating system to function.

2. A multi-user operating system allows multiple users to access a

computer system				.
4.	Cooperative				is achieved by relying on each process to give
time to the other processes in a defined manner.
5.	A single-tasking system has only											running program.
6.	Multi-tasking can be of two types:											.

7. Translate the text from Russian language into English.

Основные задачи операционной системы

Первая задача ОС - организация связи, общения пользователя с компьютером в целом и его отдельными устройствами. Такое общение

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осуществляется с помощью команд, которые в том или ином виде человек сообщает операционной системе. В ранних вариантах операционных систем такие команды просто вводились с клавиатуры в специальную строку. В последующем были созданы программы - оболочки ОС, которые позволяют общаться не только с ОС не только текстовым языком команд, а с помощью меню (в том числе пиктографического) или манипуляций с графическими объектами.

Вторая задача ОС - организация взаимодействия всех блоков компьютера в процессе выполнения программы, которую назначил пользователь для решения задачи. В частности, ОС организует и следит за размещением в оперативной памяти и на диске нужных для работы программы данных, обеспечивает своевременное подключение устройств компьютера по требованию программы и т.п.

Третья задача ОС - обеспечение так называемых системных работ, которые бывает необходимо выполнить для пользователя. Сюда относится проверка, «лечение» и форматирование диска, удаление и восстановление файлов, организация файловой системы и т.п. Обычно такие работы осуществляются с помощью специальных программ, входящих в ОС и называемых утилитами.

Операционная система выполняет роль связующего звена между аппаратурой компьютера, с одной стороны, и выполняемыми программами, а также пользователем, с другой стороны.

ОС обычно хранится во внешней памяти компьютера - на диске. При включении компьютера она считывается с дисковой памяти и размещается в ОЗУ.

Этот процесс называют загрузкой ОС. В функции ОС входит:

• осуществление диалога с пользователем;

• ввод-вывод и управление данными;

• планирование и организация процесса обработки программ;

• распределение ресурсов (оперативной памяти, процессора, внешних устройств);

• запуск программ на выполнение;

• всевозможные вспомогательные операции обслуживания; •передача информации между различными внутренними

устройствами;

• программная поддержка работы периферийных устройств (дисплея, клавиатуры, принтера и др.).

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Unit 7. TELECOMMUNICATIONS

Warm-up

1. What is telecommunication?

2. Can you give any examples of telecommunications systems?

Reading

J. Read and translate the text using a dictionary if necessary.

Telecommunications: what is it and how does it work?

Telecommunications embraces all devices and systems that transmit electronic signals across long distances. Telecommunications allows people around the world to contact one another, to access information instantly, and to communicate from remote areas. Telecommunications usually involves a sender of information and one or more recipients linked by a technology, such as a telephone system, that transmits information from one place to another. Telecommunications devices convert different types of information, such as sound and video, into electronic signals. The signals can then be transmitted by means of media such as telephone wires or radio waves. When a signal reaches its destination, the device on the receiving end converts the electronic signal back into an understandable message, such as sound over a telephone, moving images on a television, or words and pictures on a computer screen. Telecommunications enables people to send and receive personal messages across town, between countries, and to and from outer space. It also provides the key medium for news, data, information and entertainment.

Telecommunications messages can be sent in a variety of ways and by a wide range of devices. The messages can be sent from one sender to a single receiver (point-to-point) or from one sender to many receivers (point-to-multipoint). Personal communications, such as a telephone conversation between two people or a facsimile (fax) message, usually involve point-to-point transmission. Point-to-multipoint telecommunications, often called broadcasts, provide the basis for commercial radio and television programming.

How Telecommunications Works

Telecommunications begin with messages that are converted into electronic signals. The signals are then sent over a medium to a receiver, where they are decoded back into a form that the person receiving the message can understand. There are a variety of ways to create and decode signals, and many different ways to transmit signals.

Telegraphs, telephones, radio, and television all work by modifying electronic signals, making the signals imitate, or reproduce, the original message. This form of transmission is known as analog transmission. Computers and other types of electronic equipment, however, transmit digital information. Digital technologies convert a message into electronic form first by measuring

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different qualities of the message, such as the pitch and volume of a voice, many times. These measurements are then encoded into multiple series of binary numbers, or Is and Os. Finally, digital technologies create and send electrical impulses that correspond to the series of Is and Os. Digital information can be transmitted faster and more clearly than analog signals, because the electrical impulses only need to correspond to two digits and not to the full range of qualities that compose the original message, such as the pitch and volume of a human voice. While digital transmissions can be sent over wires, cables or radio waves, they must be decoded by a digital receiver. New digital telephones and televisions are being developed to make telecommunications more efficient.

Most personal computers communicate with each other and with larger networks, such as the Internet, by using the ordinary telephone network. Since the telephone network functions by converting sound into electronic signals, the computer must first convert its digital data into sound. Computers do this with a device called a modem, which is short for modulator/demodulator. A modem converts the stream of Is and Os from a computer into an analog signal that can then be transmitted over the telephone network, as a speaker's voice would. The modem of the receiving computer demodulates the analog sound signal back into a digital form that the computer can understand.