Software
Implementation of information processes
Software classification
Operating system: functions, structure, classification
Files and file system
Computer viruses. Antivirus programs
Software classification.
Software ( Software ) is an integral part of the computer. It is a logical continuation of computer technical means, expanding their capabilities and scope of use.
Software is a collection of programs executed by a computing system.
1. System software- a set of programs that defines the system environment on a computer and the rules for working in it. Implements
· computer resource management.
· creating copies of used information.
· checking the functionality of computer devices.
· issuing reference information about the computer, etc.
The system software consists of
- Operating system
- Dialog (operational) shells
- Service programs (utilities)
operating system is a basic and necessary component of computer system software. See below for information on the operating system.
Dialog (operating shells) - programs that act as an intermediary between the user and computer software
Functions:
Making it easier for the user to perform file operations (quick search, copy, delete, etc.);
More convenient launch of applications;
The ability to move faster from one application to another when multitasking.
Service programs(utilities) special maintenance (service) programs: diagnostic programs; disk maintenance programs; programs for working with CD/DVD; archivers; antivirus programs, etc.
2. Application software, directly ensuring the implementation of the work required by users. Each application environment is designed to create and study a certain type of computer object.
Separate
· General purpose software
A set of application programs that are useful to most users, regardless of their professional interests.
Text editors and processors
WordPad, MS Word, MS Publisher, Promt, Socrates
Graphic editors and graphics packages
Paint, MS PhotoDraw, Corel Xara, Corel Draw, Adobe Photoshop
Database management systems (DBMS) MS Access
MS Excel spreadsheet processors
Multimedia presentation packages MS PowerPoint, Movie Maker
Communication programs Internet Explorer, Mozilla Firefox, Opera, MS Outlook
Computer gaming programs
Special purpose software
Specialized programs (professionally oriented) for solving information problems, intended for a narrow circle of users.
Music and sound editors
Accounting programs
And packages
Expert systems
Math packages
Computer-aided design (CAD) systems
Electronic educational publications and resources
3. Instrumental software systems, facilitating the process of creating new computer programs. This class of programs is intended for creating system and application software.
Programming system is a system for developing new programs in a specific programming language.
Modern programming systems usually provide users with powerful and convenient program development tools. These include:
· compiler or interpreter;
· integrated development environment;
· tools for creating and editing program texts;
· extensive libraries of standard programs and functions;
· debugging programs, i.e. programs that help find and fix errors in the program;
· user-friendly dialogue environment;
· multi-window operating mode;
· powerful graphic libraries; utilities for working with libraries;
· built-in assembler;
· built-in help desk;
· other specific features.
Popular programming systems are Turbo Basic, Quick Basic, Turbo Pascal, Turbo C.
Translator (English translator - translator) is a translator program. It converts a program written in one of the high-level languages into a program consisting of machine instructions. Translators are implemented as compilers or interpreters. In terms of doing the work, the compiler and interpreter are significantly different.
Compiler (eng. compiler - compiler, collector) reads the entire program, translates it and creates a complete version of the program in machine language, which is then executed.
Interpreter (English interpreter - interpreter, interpreter) translates and executes the program line by line.
Once a program is compiled, neither the source program nor the compiler are needed anymore. At the same time, the program processed by the interpreter must be re-translated into machine language each time the program is launched.
Compiled programs run faster, but interpreted ones are easier to fix and change.
Each specific language is oriented either towards compilation or interpretation - depending on the purpose for which it was created. For example, Pascal is usually used to solve rather complex problems in which program speed is important. Therefore, this language is usually implemented using a compiler.
On the other hand, BASIC was created as a language for novice programmers, for whom line-by-line execution of a program has undeniable advantages.
Sometimes there is both a compiler and an interpreter for the same language. In this case, you can use an interpreter to develop and test the program, and then compile the debugged program to improve its execution speed.
System software is designed to work with the files and programs that make up a computer's operating system. System files include function libraries, system services, printer drivers, settings, and configuration files. Programs that are included in the system include assemblers, compilers, file management tools, utilities and debuggers.
Introduction
Windows system software is installed on your computer when you install the operating system. You can update your software by running programs such as Windows Update or Software Update for Mac OS X. However, unlike application programs, system software is not intended for the end user and is aimed at professional developers.
Because system software runs at the base level of the computer, it is called "low-level". This functionality generates a user interface and allows the operating system to interact with the hardware. Works in the background.
Concept of system software
System software and application programs are the two main types of machine-human interaction. Unlike open source software, an application program, often called an application, performs a specific function for the user. Examples of such software solutions:
browsers;
email clients;
word processors;
spreadsheets.
System software is designed to run computer hardware and application programs. If we consider a computer system as a multi-level model, open source software is an interface for interaction between hardware and user applications.
What is included in the system software?
According to some definitions, system software includes system utilities, such as system recovery, as well as development tools - compilers and debuggers.
manage internal memory sharing between multiple applications;
processing input and output to connected hardware devices—hard drives, printers, and switched ports;
sending messages to each application or interactive user about the status of the operation and possible errors;
Batch job management.
On computers that can support parallel processing, the operating system can manage multitasking processes.
All major computer platforms (hardware and software) include an operating system that is designed with different features to meet the specific needs of the modern consumer.
Types of OS
Types of desktop operating systems:
Windows is Microsoft's flagship operating system and the de facto standard for home and business computers;
Mac OS is an operating system for Apple Macintosh personal computers and workstations;
Linux is a Unix-like operating system that was designed to provide personal computer users with a free or very low-cost alternative (Linux has a reputation for being very efficient and fast).
Windows operating systems have traditionally dominated the market. As of August 2018, Windows has a market share of over 85 percent. Mac OS was just over 6 percent, and Linux was over 2 percent.
Mobile OS
Mobile OS allows smartphones, tablets and other mobile devices to run applications and programs. The most popular mobile operating systems:
Windows 10 Mobile.
The embedded operating system is designed for use on computers embedded in larger systems such as automobiles, traffic lights, digital televisions, ATMs, aircraft controls, point-of-sale (POS), digital cameras, GPS navigation systems, elevators, digital receivers, and smart counters.
System software (system software);
Software Basics
Section 5 Computer software
Lecture 10
in the discipline "Informatics and ICT"
TOPIC 2 “ORGANIZATION AND OPERATION OF COMPUTERS”
5.1. Software Basics
5.2. System software (system software);
5.3. System Software Specifications
One of the fundamental principles The construction of modern computers is based on the principle of program control, which consists in the fact that the sequence of computer actions is determined by a predetermined program. This principle ensures the versatility of the computer, since the computer can be used to solve any problem that is described by a sequence of actions leading to the required result.
Computer program (electronic computer)- an objective form of representation of a set of data and commands intended for the operation of computers and other computer devices in order to obtain a certain result, including preparatory materials obtained during the development of a computer program and the audiovisual displays generated by it. Law of the Russian Federation dated 07/09/93 N 5351-I, art. 4.
For normal user work, one program that provides a solution to a specific problem is not enough, therefore, in the architecture of a computer, a broader concept is used - software. Software Computers are called soft hardware or SOFTWARE.
Software- a set of programs, procedures and rules that ensure the interaction of hardware, as well as user interaction with the computer system. The computer software operates at several interconnected levels, forming a hierarchy in which each subsequent level is based on the software of the previous levels.
Depending on the functions performed by the software, it can be divided into 2 groups:
2. Application software(application software).
System software (system software) organizes the process of information processing on a computer and provides a normal working environment for application programs. System software is so closely related to the hardware that it is sometimes considered part of the computer.
Further development of technology initiated the emergence of new groups of operating system functions. The appearance of a keyboard for manually entering information into a computer led to the inclusion in the operating system of programs that process signals from the keyboard and pre-decrypt them. With the advent of monitors for convenient presentation of intermediate and final results of programs, the inclusion in the operating system of control functions for displaying text and graphic information on the display screen is associated.
Another typical function when working on a computer, it controls various external devices (hard drives, floppy disks, monitors, keyboards, etc.). These devices are produced by a variety of companies. Equal in purpose, they can have different characteristics and be controlled in completely different ways. To control an external device brand of a certain company, you need your own special program, which is called device driver .
There are printer drivers, floppy drive drivers, mouse drivers, etc. If a computer is equipped with a certain set of external devices of some brands, then at the same time its software must include the corresponding drivers. Modern operating systems include a large set of different standard drivers. Moreover, when you turn on the computer, they can automatically detect the type of device being used and connect the appropriate driver to work (this service is called Plug & Play). Naturally, this is only possible if the device is “able” to answer questions about its brand (major computer manufacturers provide this service).
All modern operating systems (for example, UNIX or Windows NT) provide multitasking (simultaneous execution of several programs) and multi-user (simultaneous operation of several users) modes of computer operation. Multitasking mode means the simultaneous operation of several programs on a computer. Of course, if a computer contains one central processor, it can only run one program, but the operating system organizes the computer in such a way that it creates the illusion that several programs are running simultaneously.
Multitasking computer operation requires that the operating system provide the following capabilities:
Parallel (pseudo-parallel) execution of several programs;
Placing tasks (i.e. programs) in a queue for execution;
Division of processor resources, memory and access to external devices between programs.
Multiplayer mode The operation of a computer system (in particular, one computer) involves the work of several users.
In multi-user mode, the following must additionally be performed:
Separation of processor resources, memory and access to external devices in accordance with user requests and priorities;
Protecting one user's data from access by other users.
Time sharing mode This is an organization of multitasking and multi-user work of programs on one computer, in which each program, depending on its priority, is allocated a time slice during which only this program works. In this case, only a small part of the program is constantly in the computer’s RAM, and the main part of it is loaded while the program is running and unloaded (released) after the end of the time slice allocated to the program.
This option is often used when the computer is running one main (usually interactive) program, which is often in standby mode, and another (computing) program that requires a large amount of processor time or external devices. When the first program waits, the second one runs, when the first program starts running, the second one stops. In this case, the second program is said to be running in the background. interaction with the operating system
Operating systems have evolved a lot since its inception. At first, several versions of the operating system were used on computers from various companies. For a number of reasons, by the mid-1970s, most computers used the company's machine instruction system and operating system IBM, named disk operating system (DOS) . The same company was one of the pioneers in the development of personal computers. Those models of personal computers that borrowed the architecture and command system of the company IBM, began to be called IBM PC-compatible computers.
Based on operating system DOS Several operating systems have been developed for such computers. Subsequently, almost all PC-compatible personal computers began to be serviced by the company’s operating system Microsoft, called MS DOS. Over time, new versions appeared MS DOS, including more and more new services, but in general the concept of the operating system of this company has remained unchanged.
The most important consequence of the use of operating systems when operating a computer is that, since typical operations of an application program are performed by OS utilities, the program can only work with the operating system for which it is oriented, i.e. programs have become relatively independent of the computer, the main thing is that the required OS runs on it. Modern operating systems are based on the concept of a virtual machine.
Virtual machine called an abstract machine with improved characteristics of RAM (called virtual memory) and an unlimited number of external devices, ensuring absolute security of data of different programs. Application systems are focused on such an ideal virtual machine, and the task of the operating system is to organize the operation of a real computer in such a way that, from the point of view of the application program, it looks like a virtual machine. Implementation of a virtual machine using operating system tools is called emulation virtual machine.
The emergence of computer networks led to the emergence of a new class of standard problems. To ensure network communication between personal computers, network shells began to be used (for example, the system NetWare companies Novell). Network shells, although they are often called operating systems, are not full-featured operating systems, since they assume that each individual computer runs its own operating system. The functions of the network shell are performed by network modules that operate on network computers.
From the point of view of the OS of a separate computer, these network modules are application programs. The network shell takes on all the functions of ensuring the process of data transfer between computers using the following technique: for the user of one computer, the data on another computer is presented as another external storage medium (disk) of this computer. When trying to read a file on this disk (data or program) into RAM, the operating system will contact the network module, and the routines included in Novell, will ensure the correct transfer of data from one computer to another.
The next step in the development of operating systems was the inclusion of network functions in them. Such network operating systems include, for example, the operating system Windows NTn different versions UNIX. These systems provide operation both on a separate computer and on a network. At the same time, they are assigned many additional network functions - actions related to establishing communications between network nodes and transmitting data in the network.
However, the operating system functions discussed above also partially change. First of all, this applies to the file system. When using network operating systems, the network file space is uniform, although different disks are physically located on different media on different computers. The user can perform the same operations with files that he performs with files on a separate computer, without worrying about the fact that this is actually moving information from one computer to another.
Network OS are always multi-user: you have to keep track of who launched a specific program and who is using a file open in the system. An important function of a network operating system is to provide user access! to data and programs. This function has two aspects: checking the privacy level of the data and checking the user's privileges.
The network system has a mechanism for encoding the level of access to data and encoding user privileges in such a way that it can always be determined whether a given user has access to a given disk, directory or individual file. In addition, various password systems are used to ensure that data is accessible only to the user who is the owner of the data or who is authorized to use the data in full or with restrictions (for example, read-only).
Service software is a set of auxiliary programs designed to diagnose and configure hardware and software, to optimize data exchange and to perform other special tasks. Many utility programs are part of the operating system, but this is not necessary - a significant number of utility programs exist separately from the OS.
Let's highlight some important types of service programs.
Service programs (utilities)- auxiliary programs to provide control with input/output and processing devices and provide processed data in a user-friendly form.
Utilities- these are programs that perform any separate auxiliary functions to ensure the operation of other programs or hardware elements in order to correct errors or expand the capabilities of working with a computer. For example, programs for diagnosing and setting up equipment, formatting storage media, writing and reading data, archiving data, anti-virus scanning, etc. are utilities. Utilities, as a rule, have a user interface, i.e., they are launched and controlled by users.
Let's look at some types of utilities.
Archive programs allow, through the use of special information packaging algorithms, to compress information on disks, i.e. create smaller copies of files, as well as combine copies of several files into one archive file. The use of archiver programs is very useful when creating an archive of files, since in most cases it is much more convenient to store them after having previously compressed them with archiver programs. Representatives of these programs are WinRar and WinZip.
Programs for creating backup copies of information allow you to periodically copy important information located on your computer’s hard drive to additional media. Representatives of backup programs - APBackUp, Acronis True Image.
Antivirus programs are designed to prevent infection by computer viruses and eliminate the consequences of virus infection. Representatives of the antivirus program family are McAfee, Kaspersky Antivirus, DrWeb, Norton Antivirus.
Programs for computer diagnostics allow you to check the computer configuration (amount of memory, its use, types of disks, etc.), check the performance of computer devices, and evaluate its performance. Representatives of computer diagnostic programs - Sisoft Sandra, Norton System Information.
Disk optimization programs allow for faster access to information on the disk by optimizing the placement of data on the disk. These programs move all sections of each file closer to each other (eliminate fragmentation), collect all files at the beginning of the disk, etc., thereby reducing the number of disk head movements (i.e., speeding up data access) and reducing wear on the disk. Representatives of disk optimization programs - Norton Disk Doctor, Microsoft Scandisk.
Screen printing programs are very useful when using graphic programs to print out the contents of the screen, since this cannot always be done using the graphics program itself. Representatives of screen printing programs - SnagIt, HyperSnap-DX.
Let us now consider programs related to service software, but not utilities.
Shells are programs that implement a user interface, i.e. intended for data exchange between a computer and a user. For example, Windows OS contains a built-in shell - the Explorer program. But instead, you can use other shells, for example, the Windows Commander program, which is not included in the Windows OS.
Drivers are device management programs. Designed to facilitate interaction between the device and the operating system. The driver is a software addition to the device and is developed by the device manufacturer. Drivers for many devices are included with the operating system.
Software development systems (programming systems) is a special group of software that is not related to either system or application software. Programming systems are a set of programs for developing, debugging and implementing new software products.
Programming systems usually contain:
· translators;
· program development environment;
· libraries of reference programs (functions, procedures);
· debuggers;
· auxiliary programs.
Programming language translators- translation of the format of source programs (written by the programmer) into the required format for working with a given operating system.
Maintenance programs- to ensure the operation of various technical means used in information systems.
System software ensures the operation of the computer, but does not solve any problems of processing information that is interesting to the user. These functions are performed by the next level of software - application software - the most important class of computer programs for the user.
Software classification
By functional purpose Three classes of software products can be distinguished, which are presented in the table.
PC Software Classification
The system software may include application programs (usually universal or gaming ones). Thus, the Windows operating system includes text editors WordPad and Notepad, which are universal application software. At the same time, in an application that refers to application software, system programs can also be used. However, from the point of view of the main purpose of a particular system (application) application, the application (system) program is of a service nature. In this case, application programs always use system programs when accessing the required hardware resources.
System software is the main software an integral part of the computer. Without it, it is impossible to interact with any computer device. It is the system software that manages the coordinated operation of all elements of the computer system, both at the hardware and software levels. That's why it's called systemic.
The system software performs the following functions:
Creation of an operating environment for the functioning of other programs;
Ensuring reliable and efficient operation of the computer itself and the computer network;
Diagnostics and prevention of computer equipment and computer networks;
Performing auxiliary technological processes: archiving, anti-virus protection, file recovery and other auxiliary programs.
System software is general use programs that designed for all computer users.System software is designed so that the computer can run application programs efficiently. But system software does not directly contribute to the end user's needs.
System software includes:
Basic I/O system and firmware;
OS;
Operating shells;
Auxiliary programs – utilities.
2.4.1. Basic I/O system
Basic I/O system(BIOS - Basic Input Output System) is a set of programs that provide:
Automatic testing of equipment when the computer is turned on;
Initial loading of the operating system located on the disk;
Interaction of the operating system with various computer devices.
BIOS programs are stored in special chips - read-only memory (ROM) located on the computer's motherboard. Therefore, BIOS can be classified as a special category of computer components, occupying an intermediate position between hardware and software and being both its hardware and part of the operating system.
2.4.2. OS
The basis of the system software is the operating system (OS). Operating systems are currently a mandatory component of system software. Without an OS, the functioning of a computer and the execution of user tasks by it are impossible.
The main function of all operating systems is mediation. It consists in providing several types of interaction - interface:
Between the user and the software and hardware (user interface - a form of dialogue between the user and the PC);
Between software and hardware (hardware-software interface);
Between different types of software (software interface).
operating systemis a set of software tools created to provide a dialogue with the user, to control and coordinate all computer devices, and to control the process of executing application programs.
Other functions of operating systems are:
– file system management;
– equipment performance monitoring;
– maintenance of the file structure: navigation, creation, copying, moving, deleting, managing attributes;
– management of installation, execution and removal of applications;
– all kinds of auxiliary maintenance operations.
2.4.3. Classification of operating systems
Based on the number of simultaneously solved tasks, the operating system can be:
– single-tasking – no more than one task is performed simultaneously;
– multitasking – capable of performing several processes simultaneously.
Single-tasking disk operating systems of various companies MS DOS, PC DOS and Novell DOS were simple and economical, but became obsolete and gave way to new generation operating systems.
Modern operating systems, such as those of the UNIX and WINDOWS families, are multitasking, provide the user with a developed graphical interface, and are compatible with applications developed for MS DOS. They are hardware independent and support all types of peripheral devices. They are able to use all the capabilities of modern microprocessors and are stable in operation, as they have means of protection against failures and errors.
Based on the number of users, the operating system can be:
– single-user – serves only one user ( Windows 98);
– multi-user – serves group users (Windows NT).
Network operating systems associated with the emergence of local and global networks. Network operating systems are a set of programs that provide processing, transmission and storage of data on the network. The network OS provides users with various types of network services (file management, e-mail, network management processes, etc.) and supports work in subscriber systems.
Since the 90s, almost all known operating systems have become network-based. The computer is turning into a means of communication with advanced computing capabilities.
Network operating systems are subject to the following requirements:
– ability to function in an environment with heterogeneous hardware and software;
– the ability to change the complexity of the structure;
– organization of internal e-mail, teleconferences;
– ensuring the required level of security when transmitting messages over networks;
– ensuring integration with the Internet, i.e. support for relevant protocols and web server software;
– availability of developed centralized administration and management tools.
Currently, the families of network operating systems UNIX, WINDOWS, NETWARE, etc. are widely known. The UNIX operating system is focused on effective multitasking work in the network version of the computing process.
UNIX OS provides support for:
– hierarchical structure of the file system;
– I/O compatible files, devices and asynchronous processing processes;
– the most common algorithmic programming languages.
In recent years, Linux OS has become widespread and supported by large corporations. This is the 32-bit version of the Unix family. It is characterized by the ability to install on various types of computers, the openness of the system core program code, and stability in operation.
The operating system is usually stored in the computer's external memory - on disk. When you turn on the computer, it is read from disk memory and placed in the computer's RAM. This process is called loading the operating system. Thus, the OS loads automatically when the computer is turned on and is permanently (residently) located in RAM. Each program uses the services of the OS, and therefore can only work under the control of the OS that provides these services for it.
2.4.4. Types of operating systems
For IBM PC computers the main operating system from 1981 to 1995. was Microsoft's MS-DOS system. Over the years, it has evolved from MS-DOS 1.0 to MS-DOS 6.22. Operating systems compatible with it were also used - PC DOS from IBM and Novell DOS from Novell, etc. We will call these operating systems by the general name DOS.
The MS-DOS operating system made it possible to successfully work with PCs for 15 years. However, this work could not be called comfortable.
The main weak point was working with RAM. DOS could work with 640 KB of RAM.
Secondly, MS DOS is a non-graphical operating system that uses command line interface - character interface. This means that all commands must be typed letter by letter in a special line. It was necessary to know these commands well and remember how they are written. This is quite difficult for the user.
The third drawback is the single-tasking nature of MS DOS.
Therefore, several graphical shells were created: Windows 1.0, Windows 2.0, Windows 3.0, Windows 3.1 and Windows 3.11 for workgroups. Despite the fact that Windows was installed on top of the DOS OS already on the computer and was only a graphical shell, Microsoft from the very beginning preferred to position Windows as an OS. The question of whether the first versions of Windows were full-fledged operating systems still remains open.
Currently, most computers in the world run one or another version of the Windows OS from the same Microsoft company.
The Windows graphical operating system first appeared in 1995 under the name Microsoft Windows 95.
Next came Windows 98/98 SE, Windows 2000, Windows ME (Millennium Edition - “Millennium Edition”). All these systems are close relatives, they have a common name - Windows 9x. In addition to 9x, there is another family of Microsoft operating systems - Windows NT (from New Technology - “new technology”).
The successor to Windows 2000 was an operating system codenamed Whistler, which was named Windows XP (released in 2001). Under the name Windows XP there are several main versions Windows XP, but the Professional and Home Edition versions have gained the most popularity. Although Windows XP is somewhat outdated, the reliability and stability of XP is high compared to other Microsoft operating systems. Sometimes experienced users first remove Vista from their laptop and then install XP there. The main disadvantage of XP is that this system is poorly suited to work with multi-core processors and new 3D graphics standards in games.
Windows Vista. This version of Windows was released in the fall of 2006. A total of seven versions of Windows Vista were released, which can be divided into two groups - Home and Business. This version is considered the most unsuccessful version of Windows. Today, with the release Windows 7 We can consider Vista's short life to be over.
Windows 7– operating system of the Windows NT family, following Windows Vista.
The operating system went on sale on October 22, 2009, less than three years after the release of the previous operating system, Windows Vista. Having retained all the useful finds of Vista, the “seven” got rid of many of its shortcomings. For normal operation, Windows 7 requires at least 2 GB of RAM and a dual-core processor with a frequency of 2 GHz. In addition, a video card that supports DirectX10 is recommended - that is, any video card released in 2009.
The Windows 7 desktop is shown in Figure 2.1.
Rice. 2.1. Desktop view in Windows 7
Apple personal computers use different versions of the Mac OS operating system.
IBM-compatible personal computers also use the freely available Linux operating system. The creation of the Linux system began in 1991 by a Finnish student Linus Torvalds (Linus Torvalds).
The Unix operating system was created in Bell Telephone Laboratories almost half a century ago for “large” computers . Unix is a multitasking, multi-user operating system that can support a very large number of users at the same time. In addition, the system is capable of performing a large number of different functions, in particular, working as a computing server, as a database server, as a network server supporting essential network services, etc. Now there are dozens of operating systems that can be united under the general name Unix .
No later than 2020, PC users will witness even more unique operating systems and programs. Microsoft CEO Bill Gates says that they are now working on new super programs that can recognize the user's speech and handwritten text. The central point of the new operating system will be the technology of human-computer interaction through natural forms of communication, i.e. body movements, voice commands, movements of the pupils of the eyes, etc. Specialists from the Massachusetts Institute of Technology and Microsoft created the first experimental programs that allow you to move the cursor across the monitor screen by moving the user's head. Computers are already capable of understanding individual user gestures.
In the new millennium, new operating systems will be created that use microphones and video cameras instead of mice. This new type of control and maintenance of communication between the user and the computer can be called video and audio interface.
Today, most people use Windows XP, Windows Vista (2007) or the latest version of the Windows OS - Windows 7. There are important differences between these versions, but the main thing is that they are the same in the techniques and methods of operation.
2.4.5. File structure of operating systems
File– this is information of a certain type located on disk, which has Name and is one whole.
A file system is a part of the OS that allows you to work with files, store data on disk, and access it. All information in external memory is stored in the file system. The smallest physical unit of data storage on a disk is a sector (typically 512 Bytes). The smallest logical, i.e. The addressable unit of data storage is the cluster. Cluster can only contain an integer number of sectors that is a multiple of powers of two (depending on the disk capacity and the size of the file table, which indicates the clusters’ affiliation with files). The file only takes up integer number of clusters, so the file size on disk may be slightly larger than actual. For example, a file of one byte in size can occupy 4 KB on disk, therefore, the cluster size on such a disk is 4 KB (8 sectors).
Main functions of the file system:
Determining the physical location of parts (fragments) of a file on disk (clusters can be located non-contiguous - fragmented);
Determining the availability of free space and allocating it for newly created files.
The file name must meet certain requirements. These requirements may vary for different operating systems. However, any OS supports the 8.3 convention (the file name can contain from 1 to 8 alphanumeric characters of the Latin alphabet and, separated by a dot, the name extension from 0 to 3 characters). Often the extension determines the type of file and is automatically assigned by the application program in which the file is created. The OS can use the extension to open the file using the associated application.
Let's look at a few standard extensions:
1) exe – means an executable file that stores a program. For example: winword.exe;
2) bat – the so-called “batch file”, designed for sequential launch of several programs. An example is the autoexec.bat file, which is automatically executed when the computer boots;
3) hlp – help file;
4) mp3, wav, mid, mp4 – sound in digital format;
5) avi, mpg, wmv – video files;
6) vob, ifo, bup – DVD format videos;
7) txt – text files without any design;
8) rtf – text file with design (standard format);
9) doc – text files created in the Microsoft Word word processor from the Microsoft Office package of all versions except 2007 and 2010;
10) docx – text files of new versions of the word processor Microsoft Word 2007 and 2010;
11) xls – table files created in the Microsoft Excel spreadsheet processor from the Microsoft Office package of all versions except 2007 and 2010;
12) xlsx – table files created using new versions of the word processor Microsoft Excel 2007 and 2010;
13) ppt – electronic presentation files created in Power Point from the Microsoft Office package of all versions except 2007 and 2010;
14) pps – presentation files prepared for demonstration;
15) pptx, ppsx – files of electronic presentations created in Power Point 2007 and 2010;
16) bmp, jpg, tif, gif – graphic information;
17) pdf – fully formatted texts created by Adobe Acrobat; Adobe Reader is required to view files;
18) htm, html – hypertext Internet document;
19) mht – web archive;
20) arj, zip, rar, 7z, ace – archive files.
The extension tells the operating system how to process the file. For example, the operating system will try to execute any file with the .exe extension as a program, and with the .bmp extension it will be displayed on the screen using an image viewer.
Thus, file name consists of two parts: actually Name– file name and identifier identifying it type. The file name can most often be chosen arbitrarily by the user. The extension, on the contrary, is strictly tied to the file type, and changing it is contraindicated.
To the question What is included in the system software??? given by the author Neurosis the best answer is Something like this.
#
System software
These general-use programs are not associated with a specific PC application and perform traditional functions: scheduling and task management, I/O management, etc.
In other words, system programs perform various auxiliary functions, for example, creating copies of used information, providing help information about the computer, checking the functionality of computer devices, etc.
System software includes:
# operating systems (this program is loaded into RAM when the computer is turned on)
# shell programs (provide a more convenient and visual way to communicate with a computer than using the DOS command line, for example, Norton Commander)
# operating shells are interface systems that are used to create graphical interfaces, multiprogramming, etc. T.
# Drivers (programs designed to control peripheral device ports, usually loaded into RAM when the computer starts)
# utilities (helper or utility programs that provide the user with a number of additional services)
Utilities include:
# file managers or file managers
# dynamic data compression tools (allow you to increase the amount of information on disk by dynamically compressing it)
# viewer and playback tools
# diagnostic tools; control tools allow you to check the computer configuration and check the functionality of computer devices, primarily hard drives
# communication tools (communication programs) are designed to organize the exchange of information between computers
# computer security tools (backup, anti-virus software).
It should be noted that some of the utilities are included in the operating system, while the other part functions autonomously. Most of the general (system) software is included in the OS. Some of the general software is included in the computer itself (some of the OS programs and control tests are recorded in ROM or PROM installed on the motherboard). Some of the common software are stand-alone programs and are supplied separately.
Application software
Application programs can be used independently or as part of software systems or packages. Application software – programs that directly enable the necessary work to be performed on a PC: editing text documents, creating drawings or pictures, creating spreadsheets, etc.
Application software packages are a system of programs that, according to their scope of application, are divided into problem-oriented, general-purpose packages and integrated packages. Modern integrated packages contain up to five functional components: test and spreadsheet processor, DBMS, graphic editor, telecommunications tools.
Application software, for example, includes:
# Suite of office applications MS OFFICE
# Accounting systems
# Financial analytical systems
# Integrated office management packages
# CAD – systems (computer-aided design systems)
# HTML or Web editors
# Browsers – means of viewing Web pages
# Graphic editor
# Expert systems
And so on.
Answer from Legal awareness[newbie]
Just start with the smallest thing that is included in the software, here is its complete compositionComposition of application software, here is its complete composition
Programs with which the user can solve his information problems without resorting to programming are called application programs.
As a rule, all users prefer to have a set of application programs that almost everyone needs. They are called general purpose programs. These include:
- text and graphic editors, with which you can prepare various texts, create drawings, build drawings; in other words, write, draw, draw;
- database management systems (DBMS), which allow you to turn your computer into a reference book on any topic;
- table processors that allow you to organize spreadsheet calculations that are very common in practice;
- communication (network) programs designed to exchange information with other computers connected to the data in a computer network.
ROM image on Wikipedia
Check out the Wikipedia article about ROM Image