Unit 5 Operating Systems Classification

Remember the following words and word combinations.

1. allocation - распределение

2. environment – окружающая среда

3. command line interface – интерфейс командной строки

4. graphical user interface – графический пользовательский интерфейс

5. multiuser - многопользовательский

6. multiprocessing – многопроцессорная обработка, параллельная обработка

7. multitasking - многозадачность

8. multithreading – многопоточный

9. real-time – в режиме реального времени

10. simultaneously - одновременно

11. general-purpose - универсальный

12. consistent – постоянный

13. compatible - совместимый

14. respond, v - отвечать

15. require, v - требовать

16. instantly – мгновенно

Read and translate the text.

Text 1 Operating System

An operating system is a special kind of system software that is responsible for the management of all activities of the computer and the sharing of computer resources. It is considered the backbone of a computer, managing both software and hardware resources. Operating systems are responsible for everything from the control and allocation of memory to recognizing input from external devices and transmitting output to computer displays. They also manage files on computer hard drives and control peripherals, like printers and scanners.

An operating system is a program that acts as an interface between the user and the computer hardware and controls the execution of all kinds of programs. Users and application programs access the services offered by the operating systems, by means of system calls and application programming interfaces. To run a certain software in a PC, it needs to be compatible with the installed OS.

An Operating System provides services to both the users and to the programs.

• It provides programs with an environment to execute.

• It provides users with services to execute the programs in a convenient manner.

Some of the most important functions of an operating system are:

• Resource Allocation

• Memory Management

• Processor Management

• Device Management

• File Management

• Program execution

• Security

• Control over system performance

• Error detecting aids

• Coordination between other software and users.

Users interact with a computer operating system through Command Line Interfaces (CLIs) or Graphical User Interfaces known as GUIs (pronounced “gooey”). Graphical user interfaces have graphic representation of every process or application. It allows users to navigate with the help of a pointing device (a mouse or a stylus) by clicking on icons, buttons, and menus.

Each operating system's GUI has a different look and feel, so it can cause some difficulties at first when a user switches to a different operating system. However, modern operating systems are designed to be user-friendly, and most of the basic principles are the same.

Categories of os

The OS can be broadly classified into certain categories. Although one particular OS can fall into more than one category. There are multiuser, multiprocessing, multitasking, multithreading, and real-time operating systems.

A multiuser operating system enables multiple users to run programs simultaneously. This type of operating system may be used for just a few people or hundreds of them. In fact, there are some operating systems that are used to allow thousands of people to run programs at the same time.

A multiprocessing operating system allows a program to run on more than one central processing unit (CPU) at a time. This can come in very handy in some work environments, at schools, and even for some home-computing situations.

A multitasking (or time-sharing) operating systems work a little differently; they make it possible to run more than one program at a time.

A multithreading operating systems allow varied parts of one program to be used simultaneously.

Real-time operating systems are designed to allow computers to process and respond to input instantly. Usually, general-purpose operating systems, such as disk operating system (DOS), are not considered real time, as they may require seconds or minutes to respond to input. Real-time operating systems are typically used when computers must react to the consistent input of information without delay. For example, real-time operating systems may be used in navigation, medical imaging systems, robots, industrial control systems, etc.

Exercise 1. Answer the following questions.

1. What is an Operating System?

2. What is its function?

3. What role does OS play between the user and the computer hardware? How does it work? What means does it use?

4. What are the categories of OS?

5. Describe briefly each OS category.

Exercise 2. Match English words and word combinations with their Russian equivalents.

1	share resources	a	универсальная операционная система
2	backbone of a computer	b	действовать в качестве интерфейса
3	memory allocation	c	без задержек
4	to transmit output	d	прикладной программный интерфейс
5	act as an interface	e	распределять ресурсы
6	system calls	f	постоянный ввод
7	application programming interface	g	суть компьютера
8	come in very handy	h	отвечать мгновенно
9	work environment	i	томографические системы
10	respond instantly	j	распределение памяти
11	consistent input	k	вызовы системных функций
12	without delay	l	передавать выходные данные
13	medical imaging system	m	оказаться весьма кстати
14	general-purpose OS	n	рабочая среда

Exercise 3. Match the words which are very close in their meaning.

1	react	a	at the same time
2	compatible	b	particular
3	control	c	without delay
4	use	d	respond
5	simultaneously	e	convenient
6	handy	f	exploit
7	certain	g	monitor
8	instantly	h	adaptive

Exercise 4. Match the terms on the right with their definitions on the left.

1	OS which executes processes on several CPU simultaneously is called	a	multitasking
2	OS which enables a user to run more than one application at the same time is called	b	real-time
3	OS which gives a user an opportunity to exploit different parts of an application without delays is called	c	multiuser
4	OS which allows many people to have programs executed at the same time is called	d	multithreading
5	when OS is able to react to data or user calls immediately is called	e	multiprocessing

Exercise 5. Match the functions of OS on the right with their definitions on the left.

1	OS creates a process by loading a program code from the disk and allocating memory to it.	a	Program execution
2	OS handles the allocation and management of memory.	b	Memory management
3	OS is in charge of organizing data storage and handling the application program access to files stored on the disk.	c	File management
4	OS prevents unauthorized users from accessing the computer system.	d	Security
5	OS controls the functionality of all peripherals like a keyboard and printers.	e	Device management
6	OS constantly monitors the system for finding bugs and faults	f	Error detecting

Exercise 6. Make all possible word combinations from the words given below.

1	to manage	a	devices
2	to access	b	purpose
3	to execute	c	environment
4	to recognize	d	services
5	to detect	e	error
6	external	f	program
7	work	g	a file
8	general	h	input

Exercise 7. Mark the sentences: True/False/ No information.

1. OS is the most important type of application software.

2. OS serves the needs of only hardware.

3. Application programming interface serves for communication between OS and a user.

4. OS is a program that functions as an intermediary between a person and computer hardware and is responsible for the execution of any kinds of programs.

5. A user can run on his computer only those programs which correspond to the requirements of the OS installed on his computer.

6. The main function of any OS is to protect a computer from malicious programs and an unauthorized user.

7. GUI facilitates the communication between a user and a computer by means of graphical symbols used to represent a process or a program.

Exercise 8. Read and translate the text choosing the right word.

The operating system is the most important program that (develops, navigates, manages, runs) on a computer. Every general-purpose computer must have an (application, graphic user, operating, software) system to run other programs.

As computers have progressed and (developed, handled, determined, shared) so have the operating systems. There are the following (vital, basic, initial, internal) types of different operating systems. Many computer operating systems will fall into more than one of the below categories.

GUI is short for Graphical User Interface. A GUI Operating System contains graphics and (devices, lines, icons, input) and is commonly (attached, navigated, interacted, managed) by using a computer (input, output, interface, mouse). Multi-user operating system allows for multiple users to use the same computer (concurrently, initially, instantly, directly). An operating system capable of supporting and (handling, processing, loading, utilizing) more than one computer processor is called (multitasking, multithreading, multiprocessing, vital). An operating system is characterized as (multiprocessing, multitasking, general-purpose, graphical) when it is capable of allowing multiple software processes to run at the same time. An operating systems that allow different parts of a software program to run concurrently may be (defined, contained, run, applied) as (multi-user, multithreading, basic, concurrent).