Introduction
The computer itself does not have knowledge of any application. All this knowledge is concentrated in programs executed on computers. Software modern computers includes many programs - from games to scientific ones. Software (software) is an integral part computer system. It is a logical continuation of technical means. The scope of application of a particular computer is determined by the software created for it.
Software means a set of software to create and operate data processing systems using tools computer technology.
Software also includes the entire field of software design and development activities.
It includes:
Program design technology;
Program testing methods;
Methods for proving the correctness of programs;
Analysis of the quality of program performance;
Documentation of programs;
Development and use of software tools that facilitate the software design process, and much more.
Service software includes:
1. Drivers (programs through which the operating system gains access to hardware some device. They are designed to control peripheral device ports and are usually loaded into RAM when the computer starts).
Far from it full list applications: mouse connection; keyboards; connection of plotters (plotters), scanners, printers, copiers (copiers), digitizers; communication between two computers via serial data ports; connecting modems for data transmission over telephone lines; connection to a network of personal computers.
2. Utilities (auxiliary or utility programs that provide the user with a number of additional services).
Typical representatives of utilities are:
File managers or file managers;
Archivers of files, folders and disks;
Communication tools (communication programs) are designed to organize the exchange of information between computers;
Computer security tools ( backup, antivirus programs);
Dynamic disk compression programs. They allow you to increase the amount of information stored on disks by dynamically compressing it. These programs compress information when writing to disk, and when reading, restore it in its original form.
Uninstallers for applications installed on your computer. They serve as a replacement for the standard Add/Remove dialog Windows program. At the same time, they work approximately 5-10 times faster. There is a function to search for an application by keyword.
Utilities are often combined into complexes; the most popular are Norton Utilities, PC Tools Deluxe and Mace Utilities.
It should be noted that some of the utilities are included in operating system, and the other part functions autonomously.
Test software is a diagnostic tool; control tools that allow you to check the computer configuration and check the performance of computer devices, primarily hard drives. The purpose of the tests is to detect errors during the operation of a computer or computer system as a whole. Some programs perform various auxiliary functions: for example, providing help information about the computer, checking the functionality of computer devices, cleaning system registry, cleaning the disk from temporary and unnecessary files and editing the Startup folder, etc.
Programming Tools are intended for creating programs. These include languages and programming systems that provide support for all stages of work on creating programs: creating source code for a program in a programming language, compilation/interpretation, debugging, documentation, support and maintenance of software products.
Programming systems usually contain translators (compilers and interpreters); libraries of reference programs (functions, procedures), link editors, loaders and debuggers.
The linking function is to link a program from many object modules. Since each of the object modules in the program was obtained as a result of a separate translation process that works only with one specific module, calls to procedures and data located in other modules do not contain actual addresses in the object modules. The linking function is performed by a separate program called communications editor or linker. The link editor performs only the linking function - assembling a program from many object modules and forming addresses in calls to external points. The output of the link editor is a load module.
To place an object program in RAM must be found and highlighted free space in memory. To perform this function the program loader contacts the operating system, which fulfills its memory allocation request as part of the overall memory management mechanism. A loader is a program that prepares an object program for execution and initiates its execution.
Debugger is a separate application designed to find errors in a program. The debugger allows you to perform step-by-step tracing, monitor, set or change the values of variables during program execution, set and remove breakpoints or stopping conditions, etc. After all, what is the job of a debugger? To help the programmer localize an error with precision to a specific function, a specific operation, a specific variable. The operating system can also help the debugger in this difficult task.
Application software includes a wide range of programs designed for various information systems. However, these programs cannot run without the operating system (OS), which provides the environment for their execution.
Software is a set of programs, procedures and rules that ensure the interaction of hardware, as well as user interaction with the computer system. Software computer operates on several interconnected levels, forming a hierarchy in which each subsequent level is based on the software of the previous levels.
Software also includes the entire area of activity in software design and development:
- - program design technology (for example, top-down design, structural and object-oriented design, etc.);
- - methods of testing programs;
- - methods for proving the correctness of programs;
- - analysis of the quality of programs;
- - documenting programs;
- - development and use of software tools that facilitate the software design process, and much more.
Software is an integral part of a computer system. It is a logical continuation of technical means. The scope of application of a particular computer is determined by the software created for it. The computer itself does not have knowledge of any application. All this knowledge is concentrated in programs executed on computers.
The software of modern computers includes millions of programs - from gaming to scientific ones.
To a first approximation, all programs running on a computer can be divided into three categories:
- 1) application programs that directly ensure the execution of work required by users;
- 2) system programs that perform various auxiliary functions, for example: managing computer resources; creating copies of used information; checking the functionality of computer devices; issuing reference information about the computer, etc.;
- 3) instrumental software systems, facilitating the process of creating new computer programs.
When constructing a software classification, one must take into account the fact that rapid development computing technology and the expansion of the scope of computer applications have dramatically accelerated the process of software evolution.
If previously it was possible to quite simply list the main categories of software - operating systems, translators, application software packages, now the situation has changed radically.
Software development has gone both in depth (new approaches to building operating systems, programming languages, etc. have appeared) and in breadth (application programs have ceased to be applied and have acquired independent value).
The relationship between the required software products and those available on the market is changing very quickly. Even classic ones software products, such as operating systems, are constantly evolving and endowed with intelligent functions, many of which previously related only to human intellectual capabilities.
In addition, non-traditional programs have appeared, which are very difficult, if not impossible, to classify according to established criteria, such as, for example, an electronic interlocutor program.
Today we can say that the following groups of software have more or less definitely emerged: operating systems and shells; programming systems (translators, subroutine libraries, debuggers, etc.); instrumental systems; integrated software packages; dynamic spreadsheets; computer graphics systems; database management systems (DBMS); application software.
System software is a set of software tools that ensure the functionality of a computer or network and create an environment for executing separate computers or the network of those functional tasks that are assigned to them. Programmers involved in development, implementation and maintenance system support, are called system programmers. In addition, the network administrator and operators deal with the network system software.
The task of system software includes: ensuring the normal functioning of the computer system; creating an environment on the computer and on the network for running application programs; performing auxiliary procedures (copying, archiving, restoring files and databases, protecting against unauthorized access); diagnostics and prevention of computer equipment and local network.
System software is an integral part of the computer - includes basic software hardwired into permanent memory, the computer's operating system, operating shells, a network operating system. Service software organizes comfortable work for the user.
System software can be divided into base software, operating system and service software.
Basic system software is a set basic programs, built into the hardware elements at the stage of its manufacture and stored in the corresponding ROM. The main part of the basic software is the BIOS (Basic Input and Output System), recorded in ROM on motherboard. The following main BIOS functions can be distinguished.
- 1. Support for hardware interfaces
- 2. Testing the hardware components of the PC when it is turned on.
- 3. Loading the operating system.
When you turn on the computer, BIOS programs automatically launch and begin checking the hardware configuration of the computer system and the functionality of its components. Communication with operational devices is established within the appropriate hardware interfaces. If the main devices - processor, RAM or video card - are found to be inoperable, work will automatically stop. If other devices are found to be inoperable, e.g. hard drive or CD drive, operation does not stop, but a corresponding warning and a request to continue operation are issued, and communication with the inoperative device is not established. If no errors are found, the operating system starts loading.
Setting up the BIOS system is possible via BIOS program Setup, which is part of the BIOS. To run this program, you must press the Delete key after turning on the computer, but before the operating system starts loading (within a few seconds after turning on the computer). One of the BIOS settings that is used most often is to specify boot device operating system, i.e. indication on which storage medium the operating system is located. As a rule, a list of 3 media is installed in the BIOS, which are viewed in turn; if an installed operating system is detected on any of them, then this system is loaded. If no operating system is detected on any of the devices in the list, a corresponding message is displayed and a request to enter the identifier of some other device. Without an operating system, perform any program actions on the computer, except BIOS settings, impossible. If the operating system you are using is installed on your hard drive and there is no need to change this system, then it is advisable to put this in the boot list hard drive to first place. If there is a need to boot the operating system from a CD drive (when installing a new operating system), then the CD drive should be listed before the hard drive in the boot list. Many BIOS settings do not need to be changed through the program BIOS Setup- they can be installed through the appropriate operating system utilities. For example, the system clock can be set through the Date and Time section of the Panel Windows management(in this case, the corresponding BIOS parameter will be reconfigured). Modern BIOS ROMs are usually built on the basis of flash memory, so a rewrite (firmware) function is possible for them - for this, the BIOS includes appropriate programs. Rewriting the BIOS is a very critical procedure - if the rewriting stage fails, the computer will be completely inoperable.
Software
Purpose and composition of PC system software. Operating system, its purpose, types of OS, their advantages and disadvantages. The concept of device drivers.
System software ensures the operation and maintenance of the computer, as well as automation of the process of creating new programs. System software includes: operating systems and their user interface; software tools; maintenance systems.
operating system- a mandatory part of special software that ensures the effective functioning of a personal computer in various modes, organizing the execution of programs and user interaction and external devices with a computer.
User Interface(service programs) are software add-ons to the operating system (shell and environment) designed to simplify the user’s communication with the operating system.
Software tools (programming systems) are a mandatory part of the software with which programs are created. Software tools include tools for writing programs ( text editors); means of converting programs into a form suitable for execution on a computer (assemblers, compilers, interpreters, loaders and link editors), means of monitoring and debugging programs.
Technical and service are software tools for monitoring, diagnosing and restoring the performance of a computer, disks, etc.
Operating systems
There are several types of operating systems: DOS, Windows, UNIX, Macintosh OS, Linux. Other modern operating systems, such as Linux, UNIX, OS/2, have their own advantages and disadvantages. Linux provides more advanced security than Windows and has a more sophisticated interface; UNIX is used where high system reliability is required. The big disadvantage of OS/2 and UNIX is the rather meager selection of software tools, and here Windows wins over other operating systems.
Main OS functions:
· management of computer devices (resources), i.e. coordinated operation of all PC hardware: standardized access to peripheral devices, RAM management, etc.
· process management, i.e. execution of programs and their interaction with computer devices.
· Driver(English driver, plural) drivers) - computer software with the help of which other software (operating system) gains access to the hardware of some devices.
Purpose and composition of application software.
Application layer
Software at this level is a set of application programs with the help of which specific tasks (production, creative, entertainment and educational) are performed. There is a close relationship between application and system software. The versatility of the computing system, the availability of application programs and the breadth of functionality of the computer directly depend on the type of operating system available, system tools, placed in its core and the interaction of the human-software-equipment complex.
The composition and purpose of the keys of a standard American keyboard by groups (alphanumeric, functional, service, cursor movement and editing keys, keys of the additional (accounting) part of the keyboard).
Alphanumeric keys - used to enter letters, numbers, space and special characters;
Control keys - used to perform additional actions, work together with other keys;
Cursor keys - used to move the cursor;
Numeric keypad keys - used to enter numbers and symbols arithmetic operations, as well as for cursor control;
Function keys- serve to perform certain actions, for example, the F1 key often calls up help about using the program.
The additional keyboard is somewhat reminiscent of a regular calculator.
To emphasize the convenience of working with numbers and operations on numbers, an additional keyboard is often called additional numeric keypad.
Moreover, for visual control of the additional keyboard mode, an indicator is provided, which is highlighted in the figure above green color.
If the light bulb (indicator) does not light, then additional keyboard Navigation mode is turned on. If the light is on, then the digital mode is enabled on the additional keyboard.
PC software concept. Brief description software.
Software - this is a set of programs that allow you to implement on a computer automated processing information. Software is divided into system (general) and application (special).
System software ensures the operation and maintenance of the computer, as well as automation of the process of creating new programs. System software includes: operating systems and their user interface; software tools; maintenance systems.
Application software provides solutions to user problems. The key concept here is the application package.
An application package is a set of programs for solving a range of problems on a specific topic or subject.
Application software includes service software that serves to organize convenient working environment user, as well as to perform auxiliary functions (information managers, translators, etc.).
No matter how “smart” electronic computers or personal computers are, they will remain a useless “piece of iron” if they are not loaded with software. It is what makes them work, performing certain actions: making calculations, displaying text, pictures and videos, making sounds and playing music, as well as controlling other devices. All actions that a computer performs, it performs according to specific program, developed for it by a person, and the set of such programs for managing electronic computers is called software.
Software concept
In fact, the program consists of steps, sequentially performing which, the PC performs certain actions, for example, accepts characters entered from the keyboard from the user and displays them on the screen, causes the printer to print text on a paper sheet, etc. Each of of such steps is encoded in a special machine language and is called a “command”, and the collection of such commands is program code.
For the first time, the idea that any predetermined state of the system can be achieved by sequential execution of elementary commands, transferring it from one stable state to another, was proposed by an English mathematician named Alan Turing. In my essay “Computable numbers with an application to the Entscheidungsproblem (Decision problem)” he created a theoretical model, which was an abstract machine (automaton) capable of performing elementary actions and transferring it from one fixed state to another fixed state. As a result, the machine could perform simple, rudimentary operations. Such an automaton subsequently received the name in the literature - "Turing machine". The main idea was a mathematical proof that any predetermined state of this automaton can be achieved by executing a finite set of specific commands from the entire fixed set (program). Thanks to this theory, such a science (so to speak) as programming was subsequently born.
Thus, programmers - people who develop software, essentially control a personal computer using the program codes they write, forcing it to read characters entered from the keyboard, play music, play videos, etc.
Types of software
Today there is huge amount the most different programs, designed to perform perfectly different functions: arithmetic or engineering calculations, drawing, programming, playing music or films, etc. But at the same time, each of them is not performed on its own on a personal computer, it is launched, as they say, under the control of one or another operating system.
A reasonable question arises: “Why can’t you run each of the programs yourself, bypassing this very operating system, if a program is a set of codes with which you can control a computer?”
In fact, of course it is possible, and this is also practiced, for example, in CNC machines (numerical program controlled), in automatic machines in production, etc., but there are several points due to which these same operating systems were developed for personal computers and even mainframe computers.
The fact is that when it comes to a standard machine, it performs a set of simple sequential operations, for example, extend the manipulator, take the workpiece, turn around, put the workpiece in the right place. Then the operation is repeated. All the time the machine performs the same actions according to the same, one program.
In the case of a PC, the user not only wants, for example, to draw in a loaded program, he wants to listen to music at the same time, to be, as they say today, “in touch” with family and friends, i.e. at the same time At the same time, work not with one, but with several programs simultaneously.
Besides this, there is another purely practical point. When developing a program for a PC that could work independently without an operating system, it would be necessary to describe all the functions of working with computer hardware in one program: reading and writing to disk, input/output from the keyboard, working with a monitor, etc. As a result - huge time costs, large software size, dependence on the hardware platform, the presence of a large number of errors and a number of other negative aspects.
The operating system takes care of most of these “routine” operations, while providing “multitasking.” That is, the user can launch and execute on his own personal computer not one, but several programs at once.
Thus, all software can be divided into three types:
- System software;
- Application software;
- Tool software.
System software
This is a set of programs that provide control of PC hardware: processor, RAM, input/output devices, graphic systems, network devices etc. In particular, such software includes:
- Operating systems;
- Drivers- small programs that provide correct operation with one or another piece of equipment (graphics, network, sound cards, controllers, etc.);
- Additional programs, expanding the capabilities of the operating system.
The main difference between system software and its other types is that it is not aimed at performing any practical or specific tasks. It only ensures the correct operation of other programs; it is a kind of “layer” between the computer hardware on the one hand and the user’s program code on the other, ensuring their correct interaction.
Application software
This class of software is the most extensive. This is what most of the programs we use in our work refer to. everyday life. Browsers, audio and video file players, graphic and text editors, anti-virus packages, accounting and other programs that perform various calculations and calculations - all this, like many programs designed to perform specific actions, functions and user tasks, is called application software.
Tool software
This type of software is very specific software. On the one hand, it could also be classified as an applied type, but on the other hand, due to the specifics of its application and use, it is separated into a separate type (although it would be more accurate to call it a subspecies of applied).
The main function of tool software programs is to provide the ability to design, create, debug and maintain program code, i.e., in essence, these are various programming environments: compilers from high-level languages, debuggers, editors, etc.
The fact is that any computer, any computing, digital device“he doesn’t understand” our words with you. Such devices work with their own “machine language” - binary code. But programming directly into “machine code” presents certain difficulties for writing programs. Therefore, specialized software has been developed that translates the easier-to-understand words of software “high-level languages” into “machine code.” Such programs are called compilers And interpreters.
The difference is that the compiler allows you to get a file ready for execution, and the interpreter, a file that can be run on a computer, only with the help of itself. By the way, the written program text containing commands in a high-level language was called « source code» (in computer slang - “source code”).
To be fair, it should be noted that program files contain machine code not in the “binary” number system, but, as a rule, in the “hexadecimal” number system. A special system program, built into the operating system - the “command processor”, will “translate” the “hexadecimal” code into “binary”. This was done to reduce the size program files, since the “hexadecimal” notation is much more compact.
Software distribution
The distribution of any software is accompanied by a special document, which clearly stipulates all the rights and obligations of the parties transferring and using this software.
According to the method of use and distribution, all software is conventionally divided into:
- Free software. As a rule, they can be freely copied and distributed absolutely free of charge. At the same time, the distributor may charge a fee, but not for the software itself, but, for example, for recording services on a medium, data transmission channel, etc.;
- Free Software. As in the case of “free” programs, no one charges money for such programs, but the main difference from the first one is the ability to make changes to program code and distribute new versions of the resulting software along with your changes. Thus, "free" software is distributed along with the source code;
- Open source. According to the terms of the license, it must be distributed with open source code;
- Closed software. It is the private property of its authors and is distributed strictly under certain conditions. This can be either a monetary reward or other types of remuneration that do not contradict the law, which the developer may require for its use. For example, this could be a shareware distribution, in which you will need to register on the site to be able to use the program. As a rule, it is distributed without source codes.
Conclusion
The software is one of necessary conditions functioning of any computing (or, as they say now, digital) system. And it doesn’t matter what it is - whether it’s built into the equipment, whether it’s loaded from external media, in any case, only with its proper operation the computer system will perform the actions that are required of it.
Knowledge and ability to work with software is a prerequisite for any user, otherwise even a simple problem that can be solved in five minutes will confuse you and lead not only to loss of time, but also money.
Software (software) is a set special programs, allowing you to organize information processing using a PC.
Since without software the operation of a PC is impossible inin principle, it is an integral partany PC and comes with its hardware(hardware).
Program– a complete and accurate description of the sequence of actions (instructions) of a computer for processing information, written in a language understandable to the computer.
Software – a set of special programs that facilitate the process of preparing tasks for execution on a computer and organizing their passage through the machine, as well as procedures, descriptions, instructions and rules, together with all documentation associated with these components, used in the operation of the computer system.
Process information and control computer operation programs, not devices.
New software innovations have long dominated new hardware developments. The cost of a software package exceeds (sometimes several times) the cost of a computer of an adequate class.
For effective use computer, there must be a correspondence between the level of development of computer technology and software. On the one hand, the software determines functionality computer. On the other hand, installation of specific software may be limited design features computer.
Purpose of the software:
- ensuring computer functionality;
- facilitating user interaction with the computer;
- shortening the cycle from setting a task to obtaining a result;
- increasing the efficiency of using computer resources.
The software allows you to:
- improve the organization of the computer system in order to maximize the use of its capabilities;
- increase user productivity and quality of work;
- adapt user programs to the resources of a specific computer system;
- expand the computer system software.
Maximum use of the capabilities of the computing system is achieved by Firstly, due to the allocation to each user or task of minimal necessary resources for timely and high-quality solution of its problems, secondly, due to connecting a large number of users (including remote ones) to the resources of the computer system, thirdly, by redistributing resources among different users and tasks depending on system state and processing requests.
Increased productivity and quality of work of users occurs due to the automation of calculation and design procedures, implemented using a variety of programming tools (algorithmic language, application software packages) and convenient input-output devices.
The adaptability of user programs to the resources of a specific computer system is ensured by the fact that the operating system contains a means of servicing a wide range of machine configurations. In addition, the operating system allows you to create and easily configure existing programs on various devices I/O
Extension of existing software requires the following capabilities:
- user creation own programs and packages that implement both specific calculation tasks and control processes for individual devices and the entire computing system as a whole;
- supplementing existing software with programs that allow you to expand the capabilities of the operating system, work with new types of external devices, new computing systems (computers), in new areas of application.
The software is user-oriented computing systems in various fields of activity and must provide timely and adequate solutions to the assigned tasks. This makes it necessary to comply with a number of requirements for developing software components , the main ones being:
- modularity;
- scalability and development;
- reliability;
- predictability;
- convenience and ergonomics;
- flexibility;
- efficiency;
- compatibility.
Basic principles of modern software development:
- parametric versatility;
- functional redundancy;
- functional selectivity.
Programs can be installed on a computer in two ways:
- Installation from the distribution kit
- Simple copying
First (lowest) level hierarchy is occupied by the internal software of the PC, stored in its permanent memory. With its help, the PC performs basic functions determined by the hardware structure. Internal software programs work directly with computer hardware modules. As a result, they are functionally connected with them, and when replacing a certain hardware module, it is necessary to replace the internal software program designed to work with it.
Programs that service hardware modules are called driver programs or drivers. They allow, when replacing or connecting a new hardware module, not to make changes in other PC programs, but only to change the driver of the corresponding hardware module.
The internal software is software interface, ensuring the interconnection of the computer with all other programs. Access to internal software programs is made only through the software interrupt system.
The internal software performs the following main functions:
- manages a wide range of peripheral devices;
- carries out a quick check of the PC's operability when it is turned on;
- installs individual hardware modules to their original state;
- loads OS programs.
The main elements of internal software are I/O drivers, self-test program and boot program. The internal software interacts, on the one hand, with the functional modules of the PC, and on the other hand, implements the software interface of the operating system.
Self-test program designed to test PC functional modules, i.e. setting the computer circuits to their initial state by loading program registers necessary information. When checking individual functional modules of the PC, faults may be detected in them. The self-test program notifies the user of detected faults using on-screen messages and/or an audible signal.
If an error is detected, you can continue scanning your computer using diagnostic programs, loaded from a floppy disk. If the error does not disrupt the functionality of the PC, then it can be ignored at the user’s request. If a new functional module is included in the PC, then the self-test program for this module is added to the general self-test program.
Upon successful completion of the self-test, the PC is ready for operation. Control is transferred to the boot program via a software interrupt. This program is designed to read other components of the operating system into RAM. If this operation is successful, control is transferred to the program just read.
I/O Drivers are used to service PC peripheral devices. These programs work directly with the corresponding controllers, which allows the user to not know the physical organization specific device and work only with driver commands that implement its maintenance.
The drivers have the following features:
- open structure, which allows you to add new drivers to the system;
- flexibility in organizing access to drivers through software interrupts, which allows you not to fix them in strictly defined areas of memory, and quickly and easily replace them;
- a customizable structure that targets driver programs to a specific class of peripheral devices, the parameters of which are located in special tables. Drivers are configured for specific peripheral devices by changing the values in these tables;
- resident placement in RAM, allowing the driver to be used at any time from any program.
The main driver programs include: hard disk driver, video adapter driver, keyboard driver, printing device driver, system drivers (setting a timer, checking the computer configuration, determining RAM capacity), additional drivers(communication driver, etc.).
Operating system occupies second (middle) level software hierarchy. It manages computer system resources, which include operating and external memory, input/output devices and user programs. The OS interacts with the computer through the internal software interface. This makes it possible for PCs that have different hardware to work with the same operating system.
The OS is a set of PC control programs.
The composition of the software is determined by the range of tasks that the user expects to solve using a computer.
By purpose, i.e. Depending on the class of problems being solved, software is usually divided into two main groups: General (basic) and applied.
Classification of software by functionality
General software classification scheme
– a set of programs that ensure the functionality of the computer; a set of programs that organize the computing process and manage computer resources.
– a set of software tools that allow you to develop programs.
– a set of programs designed to solve problems from various spheres of human activity.
