The part of the software that interacts most closely with the hardware of the computer is the system software and, above all, the operating system.
The operating system plays the role of an intermediary between the user, programs and computer hardware. It provides the ability to run programs, maintains the health of devices, provides tools for checking and configuring various components. The more flexible and multifunctional the operating system, the more opportunities it provides, the more convenient it is to work with a computer.
Operating system (OS)- this is a complex (set) of programs that ensures the interaction of all computer devices and allows the user to carry out general computer control.
The main purpose of the OS- resource management, and the main resources that it manages are computer hardware. The OS controls the computing process and information exchange between the processor, memory, and external devices.
Since all computer devices work simultaneously, the OS ensures the separation of resources, thereby preventing the risk of conflict situations between the components of the computer system that can lead to malfunction, loss or distortion of information.
The OS implements many different features, including:
Creates a working environment and maintains a user interface;
Provides execution of user commands and program instructions;
Manages computer hardware;
Provides sharing of hardware resources between programs;
Schedules user access to shared resources;
Provides input-output operations, information storage and file system management;
Performs data recovery in case of hardware failures and software errors.
The development of operating systems has always followed the development of hardware.
An operating system is a complex of interconnected system programs, the purpose of which is to organize the user's interaction with the computer and the execution of all other programs.
The operating system acts as a link between the computer hardware, on the one hand, and executable programs, as well as the user, on the other hand.
The operating system consists of:
Control program;
A set of utilities needed to operate the operating system.
The operating system is usually stored in the external memory of the computer - on the disk. When you turn on the computer, it is read from disk memory and placed in RAM. This process is called booting the operating system.
Operating system features include:
Implementation of a dialogue with the user;
I/O and data management;
Planning and organizing the processing of programs;
Distribution of resources (RAM and cache, processor, external devices);
Launching programs for execution;
All kinds of auxiliary maintenance operations;
Transfer of information between various internal devices;
Software support for the operation of peripheral devices (display, keyboard, printer, etc.).
The operating system can be called a software extension of the computer's control device. The operating system hides complex unnecessary details of interaction with the hardware from the user, forming a layer between them. As a result, people are freed from the very laborious work of organizing interaction with computer hardware.
Requirements for modern operating systems:
Compatibility - OS must include means to run applications prepared for other OS;
Portability - providing the ability to transfer the OS from one hardware platform to another;
Reliability and fault tolerance - involves protecting the OS from internal and external errors, failure failures;
Security - the OS must contain means of protecting the resources of some users from others;
Extensibility - the OS should provide the convenience of making subsequent changes and additions;
Performance - the system must have sufficient speed.
OS classification
According to the number of simultaneously executed tasks, OS is distinguished:
Single-tasking (MS DOS, early versions of PS DOS);
Multitasking happens:
Non-preemptive (Net Ware, Windows 95/98), when the active process itself transfers control to the OS at the end to select another process from the queue;
Preemptive (Windows NT, OS / 2, UNIX) - the decision to switch the processor from one process to another is made by the OS.
According to the number of simultaneously working OS users, they are divided into:
Single user (MS DOS, Windows 3x, early versions of OS/2)
Multiuser (UNIX, Windows 2000, NT, XP, Vista). In multi-user systems, there are means of protecting user information from unauthorized access.
At the moment, about 90% of computers use the Windows operating system.
There are four main classes of operating systems:
1. Single-user single-tasking, which support one keyboard and can work with only one (at the moment) task;
2. Single-user single-tasking with background printing, which allow, in addition to the main task, to run one additional task, usually focused on printing information. This speeds up the work when issuing large amounts of information for printing;
3. Single-user multitasking, which provide one user with the parallel processing of several tasks. For example, several printers can be connected to one computer, each of which will work for "its own" task;
4. Multi-user multi-tasking, allowing several users to run several tasks on one computer. These operating systems are very complex and require significant machine resources.
The operating system for a personal computer intended for professional use must contain the following main components:
Input/output control programs;
Programs that manage the file system and schedule tasks for the computer;
A command language processor that accepts, parses, and executes commands addressed to the operating system.
Each operating system has its own command language, which allows the user to perform certain actions:
access the catalog;
Perform markup of external media;
Run programs;
Other actions.
The analysis and execution of user commands, including the loading of ready-made programs from files into RAM and their launch, is carried out by the command processor of the operating system.
To control external devices of the computer, special system programs are used - drivers. Common device drivers collectively form the basic input/output system (BIOS), which is usually stored in the permanent memory of the computer.
Brief description of some operating systems
Linux OS is a network operating system, the kernel of which is developed on the basis of Unix OS. Linux is distributed in source code and is used to create servers in computer networks and on the Internet.
Unix is a multi-user, multi-tasking operating system that includes quite powerful tools for protecting programs and files of various users. The Unix operating system is machine independent, which ensures high OS mobility and easy portability of application programs to computers of various architectures.
An important feature and an extensive set of service programs that allow you to create a favorable operating environment for users - programmers (ie the system is especially effective for specialists - application programmers).
Operating system: purpose and composition
IBM-compatible personal computers use Microsoft's Windows 9x/ME operating systems, the freely distributed Linux operating system. Apple personal computers use various versions of the Mac OS operating system. On workstations and servers, the most widely used operating systems are Windows NT/2000/XP and UNIX.
Operating systems are different, but their purpose and functions are the same. The operating system is a basic and necessary component of computer software; without it, the computer cannot work in principle.
The operating system ensures the joint functioning of all computer devices and provides the user with access to its resources.
Modern operating systems have a complex structure, each element of which performs certain functions for managing a computer.
File system management. The process of computer operation in a certain sense is reduced to the exchange of files between devices. The operating system contains software modules that manage the file system.
command processor. The operating system includes a special program - a command processor - that prompts the user for commands and executes them.
The user can give a command to launch the program, perform any operation on files (copy, delete, rename), print the document, and so on. The operating system must execute this command.
Device drivers. Various devices (drives, monitor, keyboard, mouse, printer, etc.) are connected to the computer's backbone. Each device performs a specific function (information input, information storage, information output), while the technical implementation of the devices varies significantly.
The operating system includes device drivers, special programs that manage the operation of devices and coordinate information exchange with other devices, and also allow you to configure some device parameters. Each device has its own driver.
"Plug and Play" technology (plug and play) allows you to automate the connection to your computer of new devices and ensures their configuration. During the installation process, Windows determines the type and specific model of the installed device and connects the driver necessary for its operation. When you turn on your computer, the drivers are loaded into RAM.
The user has the option to manually install or reinstall the drivers.
Graphical interface. To simplify the user's work, modern operating systems, and in particular Windows, include software modules that create a graphical user interface. In GUI operating systems, the user can enter commands using the mouse, while in command line mode, commands must be entered using the keyboard.
Service programs. The operating system also includes service programs, or utilities. Such programs allow you to maintain disks (check, compress, defragment, and so on), perform file operations (archive, and so on), work in computer networks, and so on.
Reference system. For the convenience of the user, the operating system usually also includes a help system. The help system allows you to quickly get the necessary information both about the operation of the operating system as a whole and about the operation of its individual modules.
The idea of what an operating system is has changed over time. The first computers were used only for solving mathematical problems, and computational algorithms written in machine codes served as programs. When coding programs, the programmer had to independently manage the computer and ensure the execution of his program. Over time, a set of utility programs has been created to facilitate the process of writing programs. With the development of electronics, the equipment improved and it became possible to simultaneously execute several programs, in connection with this, algorithms for switching tasks were created. A set of subroutines that provide switching was called a monitor or supervisor. However, there was a problem of interrupting the work of programs containing errors and consuming computer resources (for example, constantly occupying the processor or mistakenly writing the results of their work to RAM, where other programs are located). The way out was found in the creation of special hardware mechanisms that protect the program memory from accidental access by other programs. Since the control of these mechanisms could no longer be included in the programs themselves, a special program was added to the monitor that controls memory protection. This is how the resident monitor was created. The consistent solution of such problems was aimed at creating a universal computer capable of simultaneously solving various problems.
A resident monitor is already the beginnings of an operating system. Application programs began to contain only the implementation of their algorithm and the call for auxiliary algorithms to the monitor, while using a special set of rules called the application programming interface. The Application Programming Interface allowed the creation of abstract concepts. The concepts of file and file system appeared. In the future, many other programs were added to the resident monitor, in particular, facilitating the execution of such operations as copying files, editing texts, compiling programs from a programming language into machine code, and others. The term "resident monitor" has been transformed into the core of the operating system.
Computer startup. BIOS.
Typically, a computer starts when the power is turned on at the front of the system unit, although modern computers have such means of conserving energy that allow them to be turned off. Starting the computer is the most crucial moment of the computer's operation - at this moment there is no data or programs in the RAM. It is impossible to transfer them from the hard disk to RAM without commands. For this purpose, the processor has a special pin called RESET (restart). If a signal arrives at it (and this is exactly what happens at the moment of switching on), the processor accesses a specially allocated memory cell. It is necessary that this cell always contains certain information, even when the computer is turned off. For this, a special microcircuit is designed - ROM (Read Only Memory). This is also a memory, but a permanent one. Unlike RAM, ROM is not erased when turned off. The ROM chip programs are written at the factory. This set of programs is called BIOS - basic input / output system. This system is "built into" the computer's motherboard. Its purpose is to perform elementary actions related to the implementation of input-output operations. The BIOS also contains a computer function test that checks the functioning of the memory and devices of the computer when the power is turned on. The operation of programs recorded in the BIOS chip is displayed on a black screen with running white lines. At this moment, the computer checks its devices: it checks the RAM (how much it is and whether it is all right), the presence of hard drives, and the presence of a keyboard. If something does not work, the programs that perform the check will report a malfunction. In addition, the basic input-output system contains a program to call the boot loader of the operating system.
The operating system loader is a special program designed to initiate the system boot process.
After loading the operating system, all work with the processor and other devices is carried out through special software packages included in the operating system.
If for some reason the operating system cannot be loaded from the hard disk, then work with the computer is impossible. This happens if, for example, the hard drive or operating system is damaged. In this case, the operating system can be loaded from an external storage medium. To do this, you need a special disk, which is called the system disk. This method starts the computer when troubleshooting.
Purpose of the operating system.
Computers didn't always need an operating system. If a computer could turn on, start working and accept human commands without an operating system, then there was no need for it. Examples of such "computers" would be game consoles. They also have a processor, RAM, in which the program is located during operation, there are input devices (for example, a joystick), but there is no operating system or it is completely primitive.
Game programs for consoles (and data for them, such as music and pictures) are stored in a ROM chip (it is located in a game cartridge) or on a laser disk. When a cartridge (or a laser disc) is inserted into the console, the program automatically starts and no control is expected, except for the one set by the game scenario, therefore no operating system is needed. You can look at the prefix from the other side. By downloading the game, they fall under the control of its game “operating system”, as it were, and you can only do what is provided for in the game, for example, “run”, “jump” and “shoot”. Limitedness and non-standard do not allow calling a video game an "operating system" without quotes. This operating system must:
– be universally recognized and used as a standard system on many computers;
– work with numerous hardware devices produced by different companies, including those of the past;
- provide the ability to run a wide variety of programs written by different people and released by different organizations;
- provide tools for checking, configuring, maintaining a computer, its devices and programs that are installed on it.
Hardware and software interface.
There are two participants in a computer system - software and hardware. Software is all programs installed on a computer, and hardware is components and equipment that are inside the system unit or connected outside.
The relationship between the participants in a computer system is called an interface. The interaction between different nodes is a hardware interface, the interaction between programs is a software interface, and the interaction between hardware and software is a hardware-software interface.
In a computer, the hardware interface is provided by the hardware manufacturers. They make sure that all nodes have the same connectors and work with the same voltages. The coordination between software and hardware is handled by the operating system.
User interface.
If we are talking about a personal computer, then you can also indicate a third participant in working with a computer system - this is a person (it is customary to call him a user). The user also needs to interact with hardware and software.
There are different programs and each needs to work differently. Some programs are designed to work with the keyboard, others - to work with the mouse, others - to work with a joystick or other control devices. Some programs give out their messages in the form of texts on the screen, others in the form of graphics, others may not use the screen at all and issue messages in the form of speech or sounds. The way a person interacts with a program and a program with a person is called the user interface. If a program is designed to be easy to work with, it is said to have a good user interface. If the technique of working with the program is immediately clear, without having to study the instructions, it is said to have an intuitive interface. The concept of an advanced user interface suggests that the program has great features, but it is not easy to learn how to work with it. The flexible interface means that the program can be operated in many different ways. The concept of a hard interface means that only such work is possible, which is provided for by the instruction, and no other. The concept of a primitive interface means that the interface is easy to learn, but inconvenient to work with.
DOS OPERATING SYSTEM
DOS is the first operating system for personal computers that became widespread and was the main one for IBM PC computers from 1981 to 1995. Over time, it was practically supplanted by new, modern Windows and Linux operating systems, but in some cases DOS remains convenient and the only possible to work on a computer (for example, in cases where the user works with outdated equipment or software written long ago, etc.)
Users work with the DOS operating system using the command line, it does not have its own graphical interface. The DOS operating system has made it possible to successfully work with personal computers for 15 years, however, this work cannot be called convenient. DOS acted as an "intermediary" between the user and the computer and helped turn complex disk access commands into simpler and more understandable ones, but as it developed, it itself "overgrown" with an abundance of commands and began to restrain work with the computer. So there was a need for a new intermediary - then the so-called shell programs appeared.
A shell is a program that runs under the operating system and helps the user interact with the operating system. The shell program clearly shows the entire file structure of the computer: disks, directories, files. Files can be searched, copied, moved, deleted, sorted, modified and launched with just a few keys. Simple, clear, convenient. One of the most famous and widely used shell programs in the world is called Norton Commander (NC). The NC shell hides from the user many of the inconveniences that arise when working with the MS DOS file system, such as the need to type commands from the command line. Simplicity and ease of use is what makes NC shells popular in our time (these include QDos, PathMinder, XTree, Dos Navigator, Volkov Commander, etc.). The graphical shells of Windows 3.1 and Windows 3.11 are fundamentally different from them. They use the concept of so-called "windows" that can be opened, moved around the screen and closed. These windows "belong" to various programs and reflect their work.
DOS uses the FAT file system. One of its drawbacks is the severe restrictions on file and directory names. The name can be up to eight characters long. The extension is specified after the period and consists of no more than three characters. The extension in the file name is optional, it is added for convenience, as the extension allows you to find out which program created it and the file content type. DOS makes no distinction between uppercase and lowercase letters of the same name. In addition to letters and numbers, the file name and extension can consist of the following characters: -, _, $, #, &, @, !, %, (,), (, ), ", ^. Examples of file names in MS DOS: doom .exe, referat.doc.
Since DOS was created a long time ago, it does not meet the requirements for modern operating systems. It cannot directly use the large amounts of memory installed in modern computers. Only short file names are used in the file system, various devices such as sound cards, video accelerators, etc. are poorly supported.
Multitasking is not implemented in DOS; it cannot naturally perform multiple tasks (running programs) at the same time. DOS does not have any means of control and protection against unauthorized actions of programs and the user, which has led to the emergence of a huge number of so-called viruses.
Some components of the DOS operating system: the disk files IO.SYS and MSDOS.SYS (they may be named differently, such as IBMBIO.COM and IBMDOS.COM for PC DOS) are placed in RAM at boot and remain in it permanently. The IO.SYS file is an addition to the basic I/O system, while MSDOS.SYS implements the basic high-level operating system services.
The DOS command processor processes commands entered by the user. The command processor is located in the disk file COMMAND.COM on the disk from which the operating system is loaded. Some user commands, such as type, dir, or copy, are executed by the shell itself. Such commands are called internal or built-in. To execute the remaining (external) user commands, the command processor searches the disks for a program with the appropriate name and, if it finds it, loads it into memory and transfers control to it. At the end of the program, the command processor removes the program from memory and displays a message about the readiness to execute commands (DOS prompt).
External DOS commands are programs that come with the operating system as separate files. These programs perform maintenance activities such as formatting floppy disks (format.com), checking the status of disks (scandisk.exe), etc.
Device drivers are special programs that complement the DOS I/O system and provide support for new or custom uses for existing devices. For example, using the DOS driver ramdrive.sys, it is possible to work with an "electronic disk", i.e. a piece of computer memory that can be manipulated in the same way as a disk. Drivers are placed in the computer's memory when the operating system is loaded; their names are specified in a special CONFIG.SYS file. This scheme makes it easy to add new devices and allows you to do this without affecting the DOS system files.
MICROSOFT WINDOWS
The graphical shells Widows 1.0, Widows 2.0, Widows 3.0, Widows 3.1 and Widows 3.11 ran under MS DOS, that is, they were not independent operating systems. But since the advent of Windows has opened up new possibilities, Windows is called not a shell, but an environment. The Windows environment has the following features that distinguish it from other shell programs:
- Multitasking. It is possible to run multiple programs at the same time.
– Single software interface. The interaction between programs written for Windows is organized in such a way that it is possible to create data in some programs and transfer them to other programs.
– Single user interface. Having understood how one program written for Windows works, it is not difficult to understand another. The more programs to learn, the easier it is to learn the next program.
– Graphical user interface. Program and data files are displayed as icons on the screen. Files are manipulated with the mouse.
– Single hardware-software interface. The Windows environment provided compatibility for a variety of hardware and software. Hardware manufacturers didn't care about how to "guess" what programs their devices were supposed to work with, they only wanted to work with Windows, and then Windows made the devices work. Similarly, software makers no longer had to worry about working with unknown hardware. Their task was reduced to providing interaction with Windows.
The DOS operating system with its graphical shells Windows 3.1 and Windows 3.11 was replaced by full-fledged operating systems of the MS Windows family (first Windows 95, then Windows 98, Windows 2000, Windows XP). Unlike Windows 3.1 and Windows 3.11, they start automatically after the computer is turned on (if only one of these systems is installed).
MS Windows uses a modification of the FAT file system, VFAT, to store files. In it, the length of file and directory names can be up to 256 characters.
The Windows operating system makes extensive use of the mouse when working with windows and applications. Typically, the mouse is used to select fragments of text or graphic objects, check and uncheck boxes, select menu commands, toolbar buttons, manipulate controls in dialogs, and “scroll” documents in windows.
In Windows, the right mouse button is also actively used. By placing the mouse pointer on an object and clicking the right mouse button, you can open the so-called "context menu" containing the most common commands applicable to this object.
Shortcuts allow you to access a program or document from multiple locations without creating multiple physical copies of the file. On the desktop, you can put not only icons (icons) of applications and individual documents, but also folders. Folders are another name for directories.
A significant innovation in Windows 95 was the Taskbar. Despite the small functionality, it makes the multitasking mechanism visual and much faster the process of switching between applications compared to previous versions of Windows. Externally, the taskbar is a strip, usually located at the bottom of the screen, which contains application buttons and the Start button. On the right side of it, there is usually a clock and small icons of programs that are currently active.
The Windows desktop is designed to make it as easy as possible for the novice user, while at the same time providing the maximum amount of customization to meet the specific needs of advanced users.
LINUX OPERATING SYSTEM
Linux is the operating system for IBM-compatible personal computers and workstations. It is a multi-user operating system with a network window graphics system, the X Window System. The Linux operating system supports open system standards and Internet protocols and is compatible with Unix, DOS, MS Windows systems. All components of the system, including source texts, are distributed with a license for free copying and installation for an unlimited number of users.
This operating system was developed in the early 1990s by a student at the University of Helsinki (Finland) Linus Torvald with the participation of Internet users, employees of research centers, various foundations and universities.
As a traditional operating system, Linux performs many of the functions found in DOS and Windows, but this operating system is especially powerful and flexible. Linux provides the PC user with the speed, efficiency, and flexibility of Unix while taking full advantage of the personal machine. When working with the mouse, all three buttons are actively used, in particular, the middle button is used to insert text fragments.
From an economic point of view, Linux has another very significant advantage - it is a free system. Linux is distributed under the GNU General Public License under the Free Software Foundation, which makes this operating system available to everyone. Linux is copyrighted and not in the public domain, but the GNU General Public License is almost the same as a public release. It is designed so that Linux remains free and at the same time a standardized system. There is only one official version of the Linux kernel.
The Linux operating system inherited two other great features from Unix: it is a multiuser and multitasking system. Multitasking means that the system can perform several tasks at the same time. Multi-user mode is a mode in which several users can work in the system at the same time, and each of them interacts with the system through his own terminal. Another advantage of this operating system is the ability to install it together with Windows on one computer.
Linux can turn any personal machine into a workstation. Nowadays, Linux is the operating system for business, education and individual programming. Universities around the world use Linux in courses on programming and operating system design. Linux has become indispensable in wide corporate networks, as well as for organizing Internet sites and Web servers.
Modern Linux provides the ability to use several types of graphical interface: KDE (K Desktop Environment), GNOME (GNU Network Model Environment) and others. In each of these shells, the user is given the opportunity to work with several desktops at once (while in MS Windows there is always one desktop that has to be cluttered with windows).
The computer provides various resources for solving a problem, but to make these resources easily accessible to a person and his programs, an operating system is needed. It hides complex and unnecessary details from the user and provides him with a convenient interface for work. Operating systems may also provide other features: means of protecting information stored on computer disks; the work of several users on one computer (multi-user mode), the ability to connect a computer to a network, as well as the combination of computing resources of several machines and their sharing (clustering).
Shatsukova L.Z. Informatics. Internet textbook.http://www.kbsu.ru/~book
Anna Chugainova
The operating system is the main software that manages all the hardware and other software on a computer. An operating system, also known as an "OS", interacts with the computer's hardware and provides services that applications can use.
What does the operating system do
The operating system is the main set of software on the device that keeps everything together. Operating systems interact with device hardware. They handle everything from keyboard and mouse to Wi-Fi radio, storage and display devices. In other words, the operating system handles input and output devices. Operating systems use device drivers written by hardware developers to communicate with their devices.
Operating systems also include many software products, such as common system services, libraries, and application programming interfaces (APIs), that developers can use to write programs that run on the operating system.
The operating system sits between the applications you run and the hardware, using hardware drivers as an interface between them. For example, when an application wants to print something, it offloads that task to the operating system. The operating system sends instructions to the printer using printer drivers to send the correct signals. The application that prints doesn't need to care what kind of printer you have or understand how it works. The OS handles the details.
The OS also handles multitasking by allocating hardware resources among multiple running programs. The operating system controls which processes are running and distributes them among different CPUs if you have a computer with multiple processors or cores, allowing multiple processes to run in parallel. It also manages the system's internal memory by allocating memory between running applications.
The operating system is one big piece of software that is responsible for a lot. For example, the operating system also controls the files and other resources that programs can access.
Most software applications are written for operating systems, which allows the operating system to do a lot of the work. For example, when you launch Minecraft, you launch it on the operating system. Minecraft doesn't have to know exactly how each individual piece of hardware works. Minecraft uses various features of the operating system, and the operating system translates them into low-level hardware instructions.
Operating systems are not just for PCs
When we say "computers" run operating systems, we don't just mean traditional desktops and laptops. Your smartphone is a computer, as are tablets, smart TVs, game consoles, smart watches, and Wi-Fi routers. Amazon Echo or Google Home is a computer device that runs an operating system.
Familiar desktop operating systems include Microsoft Windows, Apple MacOS, Google Chrome OS, and Linux. The main operating systems for smartphones are Apple's iOS and Google's Android.
Other devices, such as a Wi-Fi router, may run "embedded operating systems". These are specialized operating systems with fewer features than a regular operating system designed specifically for one task, such as working with a Wi-Fi router, navigating, or managing an ATM.
Where operating systems end and programs begin
Operating systems also include other software, including a user interface that allows people to interact with the device. It can be a desktop on a PC, a touch interface on a phone, or a voice interface on a digital assistant.
An operating system is a large piece of software that is made up of many different applications and processes. The line between what is an operating system and what is a program can sometimes be a little blurry. There is no exact official definition of an operating system.
For example, on Windows, the File Explorer (or Windows Explorer) application is an integral part of the Windows operating system—it even handles rendering of your desktop interface—and the application that runs on that operating system.
The core of the operating system is the kernel.
At a low level, the "kernel" is the main computer program that underpins your operating system. This standalone program is one of the first things loaded when you start your operating system. It handles allocating memory, converting software functions into instructions for your computer's processor, and processing input and output data from hardware devices. The kernel typically runs in an isolated area to prevent unauthorized use by other software on the computer. The operating system kernel is very important, but it is only one part of the operating system.
But not everything is concrete here either. For example, Linux is just a kernel. However, Linux is still often referred to as an operating system. Android is also called an operating system and it is built on top of the Linux kernel. Linux distributions like Ubuntu use the Linux kernel and add additional software to it. They are also called operating systems.
What is the difference between firmware and OS
Many devices simply run "firmware" - a type of low-level software that is usually programmed directly into the hardware device's memory. Firmware is just a small piece of software designed to only work with the absolute basics.
When the computer boots up, it loads the UEFI firmware from the motherboard. This firmware is low-level software that quickly initializes your computer's hardware. It then loads your operating system from your computer's solid state drive or hard drive. (This solid state drive or hard drive has its own built-in firmware that manages the storage of data in physical sectors within the drive.)
The line between firmware and operating system can also be a little blurry. For example, Apple's operating system for iPhones and iPads, called iOS, is often referred to as "firmware." The PlayStation 4 operating system is officially called firmware.
These are operating systems that interact with multiple hardware devices, provide services to programs, and allocate resources to applications. However, the very simple firmware that runs on a TV remote control, for example, is not usually called an operating system.
The average user is not required to understand exactly what an operating system is. It may be useful to know what operating system you are using, what software and hardware is compatible with your device.
Basic system software
The basic software includes:
operating system (OS);
operating shells (text and graphic);
network operating system.
Operating system designed to manage the execution of user programs, planning and managing computer computing resources.
In the software and operating systems sector, the leading position is occupied by systems of the MS Windows family. Consider the most common types of operating systems.
Operating systems for personal computers are divided into:
Single- and multi-tasking (depending on the number of application processes running in parallel);
single and multi-user (depending on the number of users simultaneously working with the operating system);
non-portable and portable to other types of computers;
non-network and network, providing work in a local computer network.
Network operating systems - a set of programs that provides processing, transmission and storage of data in the network. The network OS provides users with various types of network services (file management, e-mail, network management processes, etc.), supports work in subscriber systems.
Operating shells - special programs designed to facilitate the user's communication with the commands of the operating system. Operating shells have text and graphic options for the end user interface.
The following types of text shells of the operating system are most popular: Total Commander, Windows Commander, etc.
Let's take a closer look at the operating system.
Operating system- a set of software that provides control of the computer hardware and application programs, as well as their interaction with each other and the user.
The operating system performs the following functions:
management of the operation of each block of a personal computer and their interaction;
management of program execution;
organization of information storage in external memory;
User interaction with the computer, i.e. user interface support.
Usually, the operating system is stored on a hard disk, and in its absence, a special disk is allocated, which is called the system disk. When you turn on the computer, the operating system automatically loads from disk into RAM and occupies a certain place in it. The operating system is created not for a separate computer model, but for a series of computers, in the structure of which a certain concept is laid down and developed in all subsequent models.
At the heart of any operating system is the principle of organizing the work of an external storage device. Despite the fact that external memory can be technically implemented on different material media, they are united by the principle adopted in the operating system for organizing the storage of logically related sets of information in the form of so-called files.
File- a logically connected set of data or programs, for the placement of which a named area is allocated in external memory.
The file serves as an accounting unit of information in the operating system. Any actions with information are performed on files.
Files can store various types and forms of information presentation: texts, figures, drawings, numbers, programs, tables, etc. The features of specific files are determined by their format. A format is a language element that symbolically describes the representation of information in a file.
The following parameters are used to characterize a file:
Full file name
the size of the file in bytes;
the date and time the file was created;
· special file attributes: read-only, hidden, system, archived.
Working with a computer every day, we often do not even think about the fact that with one keystroke we make millions of tiny elements activate, we force the most complex logic to work, we open and close many hidden programs and functions. We think about the operating system only when we lack functions, when new versions of already used “OSes” are released, or radically new systems are being developed. Then, chasing performance, novelty and convenience, we install a new system, discover new opportunities for the information world. But what is an operating system? How does it work and what does it actually do? What are the types of operating systems, how do they differ from each other? Which operating system is best for you? We will talk about all this.
Operating system
Let's start at the beginning and answer the first question. So, the operating system is a certain set of software tools that implement the processing and processing of user information to transfer it to machine logic to perform the tasks. As a rule, the user imagines the operating system only as a visual shell. But he is mistaken ... though only half.The structure of the operating system is a multi-layer cake, the bottom layer of which (like a cake) is the core. This is the basis, committed to keep everything under control, handle errors and commands. If you do not go into details of the structure of the PC hardware component, then this “cake” lies right on the “tray”, i.e. on machine logic. The top layer of the OS (like the creamy roses on a favorite sweet dish) is what the user sees: the images, the screensaver, the cursor, and so on.
This software cake includes:
- the cake (core) itself, consisting, as usual, of flour, butter, milk, etc. (that is, from auxiliary modules that together perform all the functions of the kernel);
- loader - impregnation for the cake, thanks to which the cream is kept on it;
- device drivers are butter, thanks to which our cake does not stick to one tray, but can be transferred to another, more beautiful or more convenient;
- the command processor is a layer of nuts between the cake and cream, thanks to which the cake is tastier and more interesting (and the operating system is faster and more functional);
- interface - those same cream roses.
What does the operating system do? In fact, she has a lot of work and she is always busy (because don't get mad at her when she makes you wait a few seconds, because she has a lot of things to do). She manages the input and output of data and distributes these and tasks to various devices, loads programs into the RAM and executes them, and generally manages the RAM, distributing it to the right and left of the various applications you run, depending on how it will be more rational to use her. The operating system also controls access to all data sources (removable and flash media, etc.), protects data and itself (from hackers, malware and user errors). All the same OS is also responsible for multitasking your PC, provides the ability to work on a computer for many users. If you think that without an operating system we would see only a black screen and white letters with numbers, you are wrong - we would not see this either, because the OS is already needed to display the letters.
What are the OS? This question is usually answered as follows: operating systems are Windows (this also includes DOS, as a rule), MacOS and its various versions and Unix-like ones. In fact, their difference is much more complicated and broader, however, this is a slightly different story (the history of the "Operating Systems" course taught to future network and system administrators). Well, we'll talk about those three that have already been named, having examined them a little closer.
And we will start by telling the reader the statistics on the use of operating systems. Studies have shown that as of October 2011, only 0.84% of users preferred Unix-like systems, while Apple's operating systems (MacOS) use 7.18%. Most of all, users of various versions of Windows - 90.13% (the source of statistical data is the site statcounter.com). If we compare these results with those of 2010, we can see that users are moving from Windows to other systems in small steps.
And now that we have become information-savvy, let's return to the more familiar user assessment of the software offered to us today in the form of the latest versions of operating systems.
Operating system Windows 7
The newest operating system released by Microsoft is . Windows 8, announced this year, is not yet available to users, so we still can’t “feel” it, and we can only next summer, according to the developers.The evolution of Windows. It all started, as we all understand, with DOS - with a simple blue screen and white letters. Probably, and until now this system has remained the fastest and most reliable, because it had a maximum connection with the hardware component and a minimum of visual effects. But it was not very functional, so various versions began to appear: the first Windows 1.01, then the "improved" Windows 2.03. On the first desktop PCs, we are more likely to remember Windows 95, then Windows 98, with which, for some reason, I still associate the nickname “stump” and the joke “about the old Pentium”. Windows Millenium made a lot of noise, from which a lot was expected, and then, which fell into the same position. Windows 7 today is considered a fairly stable and user-friendly system, and it's hard to disagree with this.
Installing Windows 7 does not take much time. Personal experience has shown that, if desired, a complete set of OS is located on the computer in 12-15 minutes, and if desired, less - in 25-30. During installation, the user receives fairly accurate indications of the ongoing processes and his actions, which is important for those who maintain their computer on their own, without having deep knowledge in this area.
This version took a lot from the previous one - for example, demands on hardware resources. It does not promise, but still it will try to work if you have less than 1 GB of RAM for a 32-bit OS, a video adapter with a margin of less than 128 MB and supports DirectX versions below 9. It will also require a reader and writer (here it will be up to you to decide DVD adapter or USB connector). It is also desirable to have 16 GB of free disk space in reserve, and preferably more. System performance is high and this cannot but please the user who wants to do everything at once: to conduct network activity in 3 browsers, and to master the latest version, and something else. Compared to previous versions of Windows, the performance of the hard drive has become stronger, the graphics have weakened somewhat. But it is perfectly compensated by far advanced hardware. Considering the overall result, Windows 7 lost a couple of positions in favor of .
Interface"friendly" as the developers say. And the desktop is configured perfectly (in the figure below we can see the window for personalizing the virtual workplace).
Yes, and the whole system has significantly expanded the number of settings, which is why a more experienced user is only a plus, and a less “savvy” one is not a minus. 
Now the sound, display, and much more are configurable. The operating system will certainly advise the user what needs to be done in order to increase productivity in a particular area of its work, increase one or another of its indicators, or solve a sudden problem with the network or debugging the program. stability and security. Those who always suffer from the inexperience of acquaintances and friends will be pleasantly amused by the fact that errors that occur due to incorrect input or other “oversights” of the user are much better worked out. This suggests that the system as a whole has become more stable. Again, I will give readers of MirSovetov an example from personal experience: even left for 10 days without reboots and shutdowns, the system did not work slower or make mistakes more often.
In order to protect itself and the user, Windows 7 will try to check everything that can cause the slightest harm to the stability and security of the PC. From now on, all media, programs from unknown developers and files with activity unusual for this extension are subject to careful control. About each step, as before, the OS will report to the user. This will annoy many, but believe me, this is for your own safety.
Among the main advantages of the new "OS" should be noted:
- multi-level security (from the most sensitive, which will sound the alarm almost every time a little bit of malicious software is launched, to the most “calm”, notifying only that a certain program intends to make changes to the system);
- the presence of many new features, for example, the "Library" function, designed to replace the outdated "My Documents";
- extension of the main menu and "Toolbars".
In general, the reviewed operating system Windows 7 Professional makes an extremely pleasant impression, although the jump from Windows XP directly to Windows 7 will be a shock for many.
Linux Mint 11
Most users of Unix-like operating systems are just some "enemy camp" for Windows users. The former are not happy with Windows because of its “slowness, heaps of errors and generally eternal dampness”, while the latter consider Unix systems “something extremely incomprehensible and not user-friendly”. The points of view of both "opponents" are understandable, but whether they are wrong - judge for yourself.History of Linux. The first Unix, however, were not too adapted for the average user, but then there were not so many ordinary users and they were all quite well “savvy” in terms of system administration. Therefore, you should not blame the developers for the lack of decent visualization, but you should praise them for their courage, because they continued to develop that branch of operating systems, which they did not really expect a good future.
A distinctive feature of Unix systems has always been that they are not monolithic, like Windows: their kernel consists of many independent modules that can work independently. This allows you to "rebuild" the system right in the process of working with it, which, of course, is liked by those who are at least a little programming. Due to its atomicity, such an “axis” works better (read more stable and faster). The process of her work is somewhat similar to picking apples: who will pick up faster, a few gnomes or 1 tall and strong person? A person will simply climb one tree and collect the fruits in a basket, then on another. And the gnomes will divide the garden among themselves according to the principle “1 worker - 1 tree” and do all the work at once. At the same time, fallen apples will be collected (probably several gardeners will be thrown into "earth" work), and those that have just ripened at the very top of the tree (the nimble and light gnome will easily reach the very top branch).
Most Unix systems do not have 1 manufacturer and developer, because its codes are open and can be rewritten by anyone and in any way - such a folk art. But some versions are still developed centrally.
The history of Linux itself began with an attempt to create a free operating system, as they say, "from scratch" as part of the GNU project. Linux took its kernel from Unix and came with a lot of bells and whistles. If the first versions of this OS were console and "incomprehensible" for most users, then the latter are already quite similar to Windows in appearance and functionality and even allow you to work with applications familiar to users of this OS.
The latest version of Linux Mint 11, which was released in May this year, was taken for consideration.
Installing Linux Mint is almost completely automated and will require user participation for only a few clicks: specifying the language, initial login password and network settings. Everything that happens during the installation, as well as what the user can or cannot do, the installation wizard notifies in "writing". The whole action will take no more than 10 minutes and will not require special knowledge and skills.
, like all Unix systems, Linux Mint has minimal. This OS will be enough for 512 MB of RAM, an integrated video adapter and 5 GB of hard drive memory. You will also need a DVD or USB. A 32-bit operating system will work fine on both 32-bit and 64-bit processors. Performance, as always on top. You can only compare 64 and 32-bit versions of the system. Despite the fact that 64 bits is the initial adaptation to increase performance, and 32 is a guarantee of compatibility, the result will be quite ambiguous: with a 32-bit “version”, graphics are more productive, but in access to data (and hence to disks ) There is no equal to 64 bits. It's just a division of labor.
Interface more than friendly. A user who is confident in the “complexity and incomprehensibility” of Linux will simply amaze the number of different settings (starting with the background and screesaver and ending with setting up updates and installing software). The OS “appearance” settings window is shown in the figure.
What does the user need from the operating system? Functionality, performance and completeness. From this point of view, Linux Mint will satisfy the requirements of any user. The fact is that the “axis” comes immediately with the minimum necessary set of drivers and software (by the way, the list of “built-in” programs has been changed, which we’ll talk about later). Access to all the richness of the operating system is carried out through the transformed menu, which personally reminded me of Windows 7. 
The programs already installed include: - browsers (in particular, Mozilla Firefox);
- an analogue of the MS Office software package, which, by the way, allows you to save documents in various formats (from txt to docx);
- programs for listening to music, viewing videos and images, as well as for editing the latter;
- programs for online communication (Jabber), etc.
Linux Mint Security- this is, first of all, the security of all "non-Windows" systems, because most viruses are written specifically for Windows, but Linux and its brethren remain on the sidelines. But besides this, of course, there are many additional means designed to protect the user and his faithful informational friend. They work for this, configure network settings, etc.
System stability, as already mentioned, is ensured by its atomicity. The fact is that an error that occurred in one of the modules will not affect the others in any way. Therefore, the OS will quietly enter data about the error and its causes into the event log, reload this module and continue working, and the user will simply not notice anything at all. You will also not be able to observe constant error notifications ... Unix is generally a very silent and balanced system.
The advantages to be noted are:
- in comparison with previous versions, the interface and customization have been significantly improved;
- the presence of a minimum set of software allows you to install the system and immediately start working with it;
- drivers and codecs supplied with the OS, as a rule, are suitable for any user's initial equipment;
- fixed OS incompatibility with Wi-Fi standard;
- Linux will perfectly become next to any other operating system and will not even think about starting to conflict with it, therefore it is not worth abandoning the already familiar “axis”.
In general, the impression of Linux Mint is good, I will say even more: this operating system fully met my expectations.
macOS Lion 10.7.2
Let's start by saying that MacOS is not just an operating system, it's a lifestyle. Believe me, this phrase has a strong justification. The fact is that MacOS was originally adapted to “its own” hardware and works on the usual IBM for us, but it doesn’t matter very much.History of macOS. Developed as a reliable and productive operating system, macOS initially surprised everyone with the fact that it worked exclusively on Apple computers. “It will be more reliable for her, and for you and me it will be calmer!” The developers said, however, they nevertheless made a slight derogation from this rule and still allowed the latest versions to be installed on any hardware.
The first MacOS appeared in 1984, but something more or less similar to the beauty that we are used to seeing on Macs was invented only closer to 2000. At the same time, the first version was called very simply: System 1.0, but the pleasant ones are “Lion”, “Leopard”, etc. - this is the heritage of our times. In the process of its development, MacOS has gone from complete instability (yes, there were times when an error in the operation of 1 application simply turned off the entire system) to absolute reliability, multitasking and everything that we will talk about next.
Installing macOS Lion happens easily and naturally in the mode of dialogue between the user and his PC. In terms of time, we will regard it as 10-15 minutes, which is a good indicator. It's nice to see that already during installation, the operating system behaves extremely confidently and does everything in the promised time (she said that the files would be unpacked in 6 minutes and unpacked them in 6 minutes, so Windows users will understand me). MacOS Lion also shows its unique style already at this stage, as can be seen in the figure.
Hardware Requirements big, but justified. There is a strict requirement for the hardware manufacturer - only Apple. The OS will definitely ask you to put it on an Intel i3 processor or even newer, and it will also remind you to make sure that it has in stock: - at least 2 GB of RAM;
- 16 GB hard drive storage;
- a video card worthy of all its charms (I think at least 512 MB, although this is not indicated in the requirements).
macOS Lion Interface- this is what you can talk about for hours and days and write entire books. MacOS has always been beautiful. What is only the desktop.
"That's what a" friendly "interface is!" - said the developers and arranged everything that a user can urgently need in using a PC right at hand. It came out easy, fast and beautiful. The user is allowed to configure everything that “my darling wants”, for which “System Settings” are implemented, which are not too large-scale, but very functional: all settings are divided into categories and clearly delineated.
The operating system also comes with a set of software, so once you install it, you can get started right away. True, you will have to spend some more time getting used to all this luxury, speed and functionality, and most importantly, to the fact that there are no and will not be any “familiar and beloved” (for Windows users) applications, since with this OS most of them are simply incompatible. But there are their analogues here, which are not inferior to them either in terms of convenience or quality (for example, the beloved Mozilla browser can easily replace the no less functional Safari). macOS Lion Security is based on the fact that this OS was developed already in the era of the Internet, and therefore all possible problems are necessarily provided here. Firewall and antivirus are also their own, and built-in, of course. Well, the rule “MacOS is a “non-Windows” system” also works successfully. Who will write a virus designed for only 6.5% of PC users worldwide? This is not to say that there are no viruses for MacOS, but there are few of them.
Stability provided by the Unix FreeBSD kernel, full system multitasking, hardware stability (do not forget about the requirement of a hardware platform from Apple) and many years of practice of the manufacturer and developers of the operating system. No matter how much I tried to get this system out of myself, it only kindly informed me that such actions were beyond the boundaries of my capabilities and rights. You don't even have to worry about losing your data or your work - the autosave feature won't let that happen.
The advantages of MacOS Lion can be listed for a long time, but we will note only those that appeared in this version and are absolute innovations:
- control of visual components has become easier and more beautiful thanks to the Multi-Touch gesture system;
- now all windows can be full-screen, which greatly simplifies data management;
- many programs supplied with the OS have undergone qualitative changes, after which they have become more convenient, more functional and more beautiful;
- the cost of this version surprises everyone who knows the prices from Apple.
In general, the system is very pleasant: the unique style of MacOS has not been lost, great changes have been made, and the speed of work is impressive.
Comparing these operating systems would be inappropriate, and you can see it yourself, right? It is impossible to compare systems operating on different logics, produced and developed by different companies, and generally having practically nothing in common. The term "compare" from the point of view of operating systems is allowed within the same type of systems or in the case of choosing a system for oneself. If you're "comparing" them out of a desire to choose, my advice to you is to make a list of what's important to you in an operating system (like reliability, lack of rigid hardware requirements, etc.) and consider all possible options.
