.
Computers have penetrated into all spheres of human activity, from primary education to the study of the latest technologies, the study of new types of matter that are still unknown to mankind. The use of computer technology facilitates the process of education in secondary and higher educational institutions, both for the students themselves, and for the working staff.
Due to the variety of software and hardware, today it is possible to use all the potential of computer technology. This allows you to store a huge amount of information, while taking up minimal space. Also, computer technology allows you to quickly process this information and keep it in a protected form.
The widespread use of the PC has played a huge role in the development of the labor market. Automation of information processing allows in a matter of seconds to do the work that used to take weeks, informing managers about the state of enterprises and jobs occurs instantly. The economic potential in the field of insurance and financial services is increasing due to the increased exchange of services. Introduction of computer technologies for the introduction of new forms of employment and labor organization.
Much less time is spent on the development of new projects, because there is no need to spend a lot of time on computational processes and you can fully devote time to the process itself. Computer technologies play an important role in medicine, various virtual models of the development of diseases are created, huge databases of information are created, on the basis of which new drugs for treatment are invented.
The computer today is a means of communication, and communication itself is currently the cheapest. For people with disabilities, sometimes this is the only way not only to communicate, but also thanks to modern computer technologies, such people can realize themselves and get a job.
Computer technologies have a positive effect on the development of children when used correctly. It has been noticed that with the proper selection of programs and games, children develop logical thinking better, and eye-hand coordination improves. The child develops self-confidence and self-esteem, children are more focused compared to children who do not have experience using a computer.
On the other hand, unlimited access to huge amounts of information sometimes leads to excessive use of the computer, mainly Internet addiction or addiction to computer games. And this causes both psychological and physical harm. People who are overly fond of computer games are more irritable and quick-tempered in ordinary communication. Some develop addiction to games, and if they cannot satisfy their need in the ordinary world, their mood worsens, states of increased anxiety and sometimes depression appear.
Internet addiction occurs in people who communicate excessively in social networks, and, as a rule, occurs in those who are not very sociable in everyday life, could not realize themselves. But we will not go into the essence of these problems, as these are mostly exceptions to the rule. And with the proper use of computer technology, the benefits are incommensurably greater, and we feel it more and more every day.
Information Technology - This is a class of areas of activity related to technologies for managing and processing a huge flow of information using computer technology.
Information technology, like any other, must meet the following requirements:
ensure a high degree of dismemberment of the entire information processing process into stages (phases), operations, actions;
include the entire set of elements necessary to achieve the goal;
be regular. Stages, actions, operations of the technological process can be standardized and unified, which will allow more efficient targeted management of information processes.
Informatization of society is a global social process, the peculiarity of which is that the dominant type of activity in the sphere of social production is the collection, accumulation, processing, storage, transfer, use, production of information, carried out on the basis of modern means of microprocessor and computer technology, as well as various means of information interaction and exchange.
Information technologies can be considered as an element and function of the information society, aimed at regulating, maintaining, maintaining and improving the management system of the new network society. If for centuries information and knowledge were transferred on the basis of rules and regulations, traditions and customs, cultural patterns and stereotypes, today the main role is given to technologies.
Information technologies streamline information flows at the global, regional and local levels. They play a key role in shaping the technostructure, in enhancing the role of education, and are being actively introduced into all areas of socio-political and cultural life, including home life, entertainment and leisure.
Properties of information technology:
Information technologies make it possible to activate and effectively use the information resources of society, which today are the most important strategic factor in its development.
Information technologies make it possible to optimize and in many cases automate information processes, which in recent years have taken an increasing place in the life of human society.
Information processes are important elements of other more complex production or social processes.
Information technology has entered all spheres of our life. The computer is a means of increasing the efficiency of the learning process, is involved in all types of human activity, is indispensable for the social sphere.
The development of human society requires material, instrumental, energy and other resources, including information. The present time is characterized by an unprecedented growth in the volume of information flows. This applies to almost every field of human activity. The greatest growth in the volume of information is observed in industry, trade, financial and banking and educational spheres.
Information is one of the main, decisive factors that determines the development of technology and resources in general. In this regard, it is very important to understand not only the relationship between the development of the information industry, computerization, information technology and the informatization process, but also to determine the level and degree of influence of the informatization process on the sphere of management and intellectual activity of a person.
Much attention is paid to the problems of information in general and management as an information process, due to the following objective processes:
Humanity is experiencing an information explosion. The growth of information circulating and stored in society came into conflict with the individual capabilities of a person to assimilate it;
Development of mass - communication processes;
The need to develop a general theory of information;
Development of cybernetics as a science of control;
Penetration of information technologies into the spheres of social life;
Research in the field of natural sciences confirms the role of information in the processes of self-organization of animate and inanimate nature;
Actualization of the problem of sustainable development, the formation of the information economy, the main driving force of which is the information potential, information resources;
The problem of the prospects for the development of mankind as an integrity makes it necessary to raise the question of the criteria for progress in modern conditions.
Information has become a subject of purchase and sale, i.e. an information product, which, along with information constituting the public domain, forms an information resource of society.
As a commodity, information cannot be alienated like material products. Its sale and purchase has a conditional meaning. Passing to the buyer, it remains with the seller. It does not disappear in the process of consumption.
The formation and development of the information sector, the movement of many types of information as a commodity influenced the formation of a special market - the information market.
The use of modern information technologies provides an almost instantaneous connection to any electronic information arrays (such as databases, electronic directories and encyclopedias, various operational reports, analytical reviews, legislative and regulatory acts, etc.) coming from international, regional and national information systems and use them in the interests of successful business.
Thanks to the rapid development of the latest information technologies, at present, not only has there been open access to the global flow of political, financial, scientific and technical information, but it has also become a real opportunity to build a global business on the Internet.
In the modern world, the role of informatics, the means of processing, transmitting, and accumulating information has increased immeasurably. The means of informatics and computer technology now largely determine the scientific and technical potential of the country, the level of development of its national economy, the way of life and human activity.
For the purposeful use of information, it must be collected, transformed, transmitted, accumulated and systematized. All these processes associated with certain operations on information will be called information processes. Obtaining and transforming information is a necessary condition for the life of any organism. Even the simplest unicellular organisms constantly perceive and use information, for example, about the temperature and chemical composition of the environment to select the most favorable conditions for existence. Living beings are able not only to perceive information from the environment with the help of the senses, but also to exchange it among themselves.
A person also perceives information through the senses, and languages are used to exchange information between people. During the development of human society, there were a lot of such languages. First of all, these are native languages (Russian, Tatar, English, etc.), which are spoken by numerous peoples of the world. The role of language for humanity is exceptionally great. Without it, without the exchange of information between people, the emergence and development of society would be impossible.
Information processes are characteristic not only for wildlife, man, society. Mankind has created technical devices - automata, the work of which is also associated with the processes of receiving, transmitting and storing information. For example, an automatic device called a thermostat receives information about the room temperature and, depending on the temperature regime set by a person, turns on or off heating devices.
Human activity associated with the processes of obtaining, transforming, accumulating and transmitting information is called information activity.
The development of science and education has led to a rapid increase in the volume of information and human knowledge. If at the beginning of the last century the total amount of human knowledge doubled approximately every fifty years, then in subsequent years - every five years.
The way out of this situation was the creation of computers, which greatly accelerated and automated the process of processing information.
Computers are used in production at all stages: from the design of individual parts of the product, its design to assembly and sale. The computer-aided production system (CAD) allows you to create drawings, immediately getting a general view of the object, to control machines for the manufacture of parts. A flexible manufacturing system (FPS) allows you to quickly respond to changing market conditions, quickly expand or curtail the production of a product or replace it with another one. The ease of transferring the conveyor to the production of new products makes it possible to produce many different models of the product. Computers allow you to quickly process information from various sensors, including automated security, from temperature sensors for regulating energy consumption for heating, from ATMs that record customer spending, from a complex tomograph system that allows you to "see" the internal structure of human organs and correctly place diagnosis.
The computer is located on the desktop of a specialist of any profession. It allows you to contact by special computer mail anywhere in the world, connect to the collections of large libraries without leaving your home, use powerful information systems - encyclopedias, study new sciences and acquire various skills with the help of training programs and simulators. He helps a fashion designer to develop patterns, a publisher to compose text and illustrations, an artist to create new paintings, and a composer to music. An expensive experiment can be completely calculated and simulated on a computer.
The development of ways and methods for presenting information, technology for solving problems using computers, has become an important aspect of the activities of people of many professions.
There are four intrinsically related fundamental features of the emerging information society:
The change in the role of information and knowledge in the life of society, expressed primarily in an unprecedented increase in the information saturation of economic, managerial and other areas of activity, in the transformation of information and knowledge into the most important resource for socio-economic development.
The transformation of the information industry into the most dynamic, profitable and prestigious sphere of production, which ensures the leading role of individual countries and cities in the global economy.
The emergence of a developed market infrastructure for the consumption of information and information services and, in particular, the widespread introduction of ICT in various spheres of life, not only in professional, but also in everyday life.
Profound changes in models of social organization and cooperation, when in all spheres of society there is a replacement of centralized hierarchical structures with flexible network types of organization adapted to rapid changes and innovative development.
The use of satellites, live radio and television to transmit information has a massive impact on the formation of public opinion around the world. The emergence and improvement of multimedia, video conferencing and artificial intelligence greatly expand the possibilities of information transfer, and, therefore, the dissemination and exchange of knowledge.
Harnessing the power of digital technology
undertaking economic and structural reforms to create an environment of openness, efficiency, competition and innovation, complemented by measures to adapt to labor markets, develop human resources and promote social cohesion;
sound macroeconomic management to promote more precise planning by business and consumers and to take advantage of new information technologies;
development of information networks that provide fast, reliable, secure and economical access through competitive market conditions and related innovations in network technologies, their maintenance and application;
developing human resources capable of meeting the requirements of the information age through education and lifelong learning and meeting the growing demand for IT professionals in many sectors of our economy;
the active use of IT in the public sector and the promotion of real-time services needed to improve the accessibility of power to all citizens.
Before considering the issue of computer classification, let us dwell on a number of definitions.
Information processing is an important component of the information process. Under information processing we will understand the actions performed on information presented in a formalized form, i.e. in the form of data structures, using certain algorithms - a sequence of actions carried out according to certain rules and implemented using technical means.
The result of processing is also information that meets the set goals (for example, the processing of numerical, textual, graphic and other information) and can be presented in appropriate forms. Attempts to automate the process of processing information and calculations based on discoveries in the field of mathematics, physics, chemistry, etc. for several centuries led to the creation of a modern computer or electronic computer. In modern information technologies, a computer is used as the main technical means for processing information.
Thus, computer called a technical system designed to automate the process of processing information and calculations based on the principle of program control.
Software are a set of programs that provide the process of processing information on a computer. Software tools are often referred to by the slang word "software".
The main purpose of classification is the formation of groups or classes with characteristic properties that are unique to this group or class, which makes it possible to study these properties in more detail and trace the dynamics of their change over time. At present, the classification of computers is not fixed by the relevant standards, which is explained by the high pace of development of computer technology and information technology. Approximately every two years, computer hardware and software are replaced with new ones. In this regard, any classification of computers is conditional, since some properties that were characteristic of certain groups (classes) of computers in the past lose these properties over time. We single out the most significant features and classify them. Conditional classification of computers on these grounds is given in Table. 5.1.
Table 5.1
1) By time of creation computers are divided into generations (first, second, third and fourth), which are characterized by the degree of development of hardware and software.
Computers first generation date back to the mid 40's and late 50's. 20th century (1946 the first digital electronic computer was created ENIAC). Vacuum tubes were used as the element base, programming was carried out in machine codes. The program was entered into the computer by connecting the corresponding sockets on special typeset boards with the help of electrical conductors. The maximum performance reached 20 thousand operations per second.
Computers second generation belong to the late 50's and mid 60's. 20th century Semiconductor devices - transistors - were used as the element base, which made it possible to increase the reliability and speed of computers. Programming was carried out in high-level programming languages. The program was entered into the computer using punched cards and punched tapes. The maximum performance was up to 1 million operations per second.
Computers third generation belong to the period from the mid-60s to the mid-70s. 20th century Integrated microcircuits of the middle level of integration were used as the element base. Programming was carried out in high-level programming languages. The program was entered into a computer using punched cards and punched tapes, information storage devices appeared on floppy magnetic disks. The maximum speed was about 1 million operations per second. Third-generation computers became a family of computers with a single architecture, which ensured their software compatibility. They had advanced operating systems and multiprogramming capabilities.
Computers fourth generation date back to the mid 70's. 20th century Until now. Large integrated circuits (LSI), and then (at present) very large integrated circuits (VLSI) were used as the element base, which made it possible to significantly increase the reliability and speed of computers. On the basis of LSI, and then VLSI, microprocessors were built and are being built - devices for direct execution of the data processing process and program control of this process. Programming has been and is being done in several dozen high-level programming languages, including object-oriented programming languages. Programs have been and are being entered into a computer using a variety of information carriers - floppy disk drives, hard magnetic disks, optical disks, etc. The maximum speed of fourth-generation computers is about 1 trillion operations per second.
2) According to the form of presentation of the processed information computers are divided into three classes: digital, analog and hybrid.
Digital computers process information presented in digital form (in the binary system), and are the most representative class of modern computers. Digital computers are used to solve a wide variety of problems that can be formalized, for which the corresponding numerical solution methods have been developed.
Analog computers they process information presented in analog form, i.e. in the form of continuously changing values of a physical quantity (electrical voltage or current). Analog computers are used to solve physical and mathematical problems involving differential equations. In addition, they are used in automatic control systems to solve problems in real time.
hybrid computers process information presented in digital and analog form. In such computers, the digital part is designed to control and perform logical operations, and the analog part is designed to solve mathematical equations.
3) By appointment computers are divided into three classes: professional, personal and specialized.
Professional computers designed to process large amounts of information at high speed. In terms of hardware and software, they are significantly superior to other classes.
Personal computers are designed to process information at one workstation (AWP), while their computing resources should be sufficient to support such a workplace. In addition, they must be affordable for the mass consumer.
designed to process information related to the solution of highly specialized tasks (computing and control). They do not have universality, i.e., they are focused on specific practical tasks. Specialized computers, also called controllers, are built into automatic control systems for complex technical devices or technological processes.
4) According to the degree of universality computers are divided into two classes: general purpose and specialized.
General purpose computers are universal and allow you to process information related to solving a wide range of problems.
Specialized computers allow you to process information related to the solution of narrowly professional tasks.
5) By way of use computers are divided into two classes: collective and individual use.
Community computers designed to serve multiple users at the same time. Such computers, also called servers, are also used to organize the operation of computer networks.
Personal computers designed to serve the work of an individual user.
6)According to performance computers are divided into three classes: ordinary, high and ultra-high performance.
Performance depends on the specifics of the task being solved, the speed of the computer, the information volume of its RAM, etc. The speed (information processing speed) of the computer, in turn, is determined by the speed of the microprocessor, the system backbone (used to exchange information between the functional blocks of the computer), peripheral devices, quality of design solutions, etc.
7)According to architectural features computers are divided into two classes: open architecture and closed architecture
Computer architecture is understood as a set of hardware and software organized into a system that ensures the functioning of a computer.
To features open architecture relate:
The modular principle of building a computer, in accordance with which all its components are made in the form of complete structures - modules that have standard sizes and standard interfaces;
The presence of a common (system) information bus, to which various additional devices can be connected through the appropriate plug-in connections;
Compatibility of new hardware and software with their previous versions, based on the "top-down" principle, which means that subsequent versions must support the previous ones.
The vast majority of modern computers have an open architecture.
closed architecture does not have the characteristic features of an open architecture and does not allow connection of additional devices not provided by the developer. Computers with this architecture are effective in solving highly specialized tasks, such as computing.
There are other classifications:
- Classification by purpose related to the field of application of computers:
large computers - are used to serve entire sectors of the national economy (meteorology, defense industry, railways, etc.);
minicomputers - used to serve large enterprises, research institutes, banks, etc.;
microcomputers - used to service workshops at factories, laboratories at institutes, etc.;
personal computers - used to serve one workplace.
- Classification by level of specialization
determined by the degree of universality of computers:
universal - on the basis of which it is possible to assemble computing systems of arbitrary composition (work with text, graphics, music, etc.);
specialized - designed to solve a narrow range of tasks (aircraft on-board computers, control of microwave ovens, etc.).
- Size classification depends on the design of the computers:
desktop (work stations);
portable (Notebook);
pocket (electronic notebooks);
mobile (PDA).
- Classification by compatibility level
:
by the level of hardware compatibility (IBM PC, Apple Macintosh, Sun Microsystems);
by software compatibility level (Ms Windows, Mac OS, Solaris).
The office equipment includes a fairly large list of technical means, devices and devices, ranging from pencils to complex systems and means of transmitting information.
Consider the classification of office equipment used in the creation and processing of documents in the office.
Tools for compiling and producing text and spreadsheet documents:
- hand writing instruments,
− typewriters,
− dictaphone equipment,
-printing devices for personal computers,
- means of copying and replicating documents,
− means of electrophotographic copying,
− document processing facilities,
- envelope opening machines,
−machines for applying protective coatings on documents (laminators),
−machines for destruction of documents (shredders),
− means of communication technology,
−means and systems of fixed and mobile telephone communication (including mini-ATS),
−means and systems of telegraph communication,
− means and systems of facsimile transmission of information and modem
communications,
−local (office) computer networks,
−means and systems of operational dispatch communication,
− means of transporting documents,
−office furniture and equipment.
Classification of organizational equipment for modern office technologies.
Information carriers:
- paper-based media is not photosensitive;
–carriers for reprographic processes (thermal paper, diazo paper, photographic film, tracing paper, multilayer paper for electron-spark copying, etc.);
– microcarriers;
– sound carriers;
– video media;
- magnetic media.
Bank office equipment:
−machines for bill counting;
−currency detectors;
−machines for wrapping banknotes; ATMs.
−scanners;
− multifunctional centers;
−means of protection; computer accessories.
Specialized office equipment. First of all, we are talking about technical means by which business documentation takes on a form that allows its further effective use. These can be desktop binding machines with plastic or metal springs (benders), thermal binding machines (thermobinders), desktop paper cutters. To increase the shelf life of documents, laminators are used that apply various coatings to the surface of the document sheet.
Lecture3. Architecture of the personal computer.
The basic arrangement of computer parts and the relationship between them is called architecture. When describing the architecture of a computer, the composition of its constituent components, the principles of their interaction, as well as their functions and characteristics are determined.
Rice. 1 Personal computer architecture
Almost all mainframe computers reflect the classical Neumann architecture shown in the diagram. This scheme is largely characteristic of both microcomputers and minicomputers and general purpose computers.
Let's consider the devices in more detail.
1 . The main part of the motherboard microprocessor (MP) or CPU (Central Processing Unit), it controls the operation of all PC nodes and a program that describes the algorithm of the problem being solved. MP has a complex structure in the form of electronic logic circuits. Its components are:
A). ALU - arithmetic-logical unit designed to perform arithmetic and logical operations on data and memory addresses;
B). Registers or microprocessor memory - super-rapid memory that works at the speed of the processor, the ALU works with them;
B). CU - control device - control of the operation of all MP nodes by generating and transmitting to its other components control pulses coming from a quartz clock generator, which, when the PC is turned on, begins to vibrate at a constant frequency (100 MHz, 200-400 MHz). These fluctuations set the pace for the entire motherboard;
G). Spr - interrupt system - a special register that describes the state of the MP, allowing you to interrupt the operation of the MP at any time to immediately process some incoming request, or put it in a queue; after processing the request, the SP ensures the restoration of the interrupted process;
D). The common bus control device is an interface system.
To expand the capabilities of the PC and improve the functional characteristics of the microprocessor, a mathematical coprocessor can be additionally supplied, which serves to expand the set of MP instructions.
For example, the IBM-compatible PC math coprocessor extends the MP's capabilities for floating point calculations; a coprocessor in local networks (LAN-processor) expands the functions of the MP in local networks.
Processor Specifications:
performance(performance, clock speed) - the number of operations performed per second.
bit depth - the maximum number of digits in a binary number that can be simultaneously processed by a machine operation.
2. Interface system is:
Control bus (SHU) - designed to transmit control pulses and synchronize signals to all PC devices;
Address bus (ShA) - designed to transfer the address code of a memory cell or input / output port of an external device;
Data bus (SD) - designed for parallel transmission of all digits of the numeric code;
Power bus - to connect all PC units to the power supply system.
The interface system provides three directions for information transfer:
Between MP and RAM;
Between MP and I/O ports of external devices;
Between RAM and I/O ports of external devices. Information is exchanged between devices and the system bus using ASCII codes.
3. Memory- a device for storing information in the form of data and programs. Memory is primarily divided into internal (located on the system board) and external (located on a variety of external storage media).
Inner memory is further subdivided into:
- ROM(read-only memory) or ROM (read only memory), which contains - permanent information that is stored even when the power is turned off, which serves to test the memory and computer hardware, booting the PC when it is turned on. Recording on a special ROM cassette takes place at the PC manufacturer's factory and bears the features of its individuality. Volume ROM is relatively small - from 64 to 256 KB.
- RAM(Random access memory, RAM - random access memory) or RAM (random access memory), is used for online storage of programs and data that is stored only for the duration of the PC. It is volatile, when the power is turned off, information is lost. Volume OP ranges from 64 KB to 64 MB and above, as a rule, OP has a modular structure and can be expanded by adding new chips.
- Cache memory- has a short access time, serves for temporary storage of intermediate results and the contents of the most frequently used OP cells and MP registers. Volume cache memory depends on the PC model and is usually 256 KB.
external memory. External memory devices are very diverse.
(1) Tape drives historically appeared earlier than magnetic disk drives. Reel drives are used in the supercomputer and mainframe. Tape drives are called tape drives, they are designed to create backup copies of programs and documents of value. Recording can be done on a regular video cassette or on a special cassette. Capacity such a cassette up to 1700 MB, tape length 120 m, width 3.81 mm (2 - 4 tracks). Reading speed up to 100 Kb/s
(2) Magnetic disks (MD) - as a storage medium, magnetic materials with special properties are used, which make it possible to fix two directions of magnetization. Each of these states is assigned binary numbers - 0 and 1. Information on the MD is written and read by magnetic heads along concentric circles - tracks. Each track is divided into sectors(1 sector = 512 b). The exchange between the disks and the OP is an integer number of sectors. cluster- the minimum unit of information on the disk, it can contain one or more adjacent sectors of the track. When writing and reading, the MD rotates around its axis, and the magnetic head control mechanism brings it to the track selected for recording or reading.
Disk data is stored in files- named areas of external memory allocated for storing the data array. Clusters allocated to a file can be located in any free disk space and are not necessarily contiguous. All information about exactly where the pieces of the file are written is stored in file allocation table FAT (file allocation table).
(3) HDD or "hard drives" are made of aluminum alloys or ceramics and coated with ferrolacquer, together with a block of magnetic heads are placed in a hermetically sealed case. Capacity drives due to extremely dense recording reaches several gigabytes, the performance is also higher than that of removable drives (due to an increase in rotation speed, since the disk is rigidly fixed on the rotation axis). The first model appeared at IBM in 1973. It had a capacity of 16 KB and 30 tracks / 30 sectors, which coincided with the caliber of the popular 30 "730" Winchester shotgun. Diameter HDD: 3.5" (available in 1.8" and 5.25"). Rotational speed 7200 rpm, access time - 6 ms. Each GMD undergoes a procedure low-level formatting- service information is written to the media, which determines the layout of the disk cylinders into sectors and numbers them, bad sectors are marked to exclude them from the disk operation process. The PC has one or two drives. One hard drive can be divided using a special program into several logical drives and work with them as with different hard drives.
(4) GCD(optical disc drives) are divided into:
not rewritable laser optical discs or compact discs (CD-ROM). Supplied by the manufacturer with information already written on them. Recording on them is possible under laboratory conditions with a laser beam of high power. In a PC optical drive, this track is read by a lower power laser beam. In view of the extremely dense recording, CD-ROMs have a capacity of up to 1.5 GB, access time from 30 to 300 ms, data reading speed from 150 to 1500 Kb / s;
rewritable CDs have the ability to write information directly from a PC, but this requires a special device.
magneto-optical disks(ZIP) - recording on such a disk is performed under high temperature by magnetizing the active layer, and reading is performed by a laser beam. These disks are convenient for storing information, but the equipment is expensive. Capacity such disk up to 20.8 MB, access time from 15 to 150 ms, reading speed information up to 2000 Kb/sec.
4. Controllers serve to provide direct communication with the OP, bypassing the MP, they are used for devices for quick data exchange with the OP - floppy disk drive, HDD, display, etc., to ensure operation in a group or network mode. The keyboard, display, mouse are slow devices, therefore they are connected to the system board by controllers and have their own allocated memory areas in the OP.
5. Ports are input and output, universal (input - output), they serve to ensure the exchange of information between the PC and external, not very fast devices. Information coming through the port is sent to the MP, and then to the OP. There are two types of ports:
consistent- provides a bit-by-bit exchange of information, usually a modem is connected to such a port;
parallel- provides a byte-by-byte exchange of information, a printer is connected to such a port. Modern PCs are usually equipped with 1 parallel and 2 serial ports.
6. Video monitors- devices designed to display information from a PC to the user. Monitors are monochrome(green or amber image, high resolution) and colored. The highest quality RGB monitors have high resolution for graphics and color. It uses the same principle of a cathode ray tube as a TV. Laptop PCs use electroluminescent or liquid crystal panels. Monitors can work in text and graphics modes. In text mode, the image consists of familiarity - special characters stored in the video memory of the display, and in graphic The image consists of dots of a certain brightness and color. The main characteristics of video monitors are resolution (from 600x350 to 1024x768 pixels), number of colors (for color) - from 16 to 256, frame rate fixed at 60 Hz.
7. Printers- these are data output devices from a computer that convert information ASCII codes into their corresponding graphic characters and fix these characters on paper. Printers are the most developed group of external devices, there are more than 1000 modifications.
Printers are black and white or color according to the printing method, they are divided into:
matrix- in these printers, the image is formed from dots by impact, the needle print head moves in a horizontal direction, each needle is controlled by an electromagnet and hits the paper through the ink ribbon. The number of needles determines the print quality (from 9 to 24), print speed 100-300 characters/sec, resolution 5 dots/mm;
jet- instead of needles, the print head has thin tubes - nozzles through which tiny droplets of ink are ejected onto the paper (12 - 64 nozzles), print speed up to 500 characters/sec, resolution- 20 points per mm;
thermographic - dot matrix printers equipped with a thermal matrix instead of a needle print head; special thermal paper is used for printing;
laser- an electrographic method of image formation is used, the laser is used to create an ultra-thin light beam that traces the contours of an invisible dot electronic image on the surface of the photosensitive drum. After developing the image with dye (toner) powder adhering to the discharged areas, printing is performed - transferring the toner to paper and fixing the image on paper using high temperature. Permission such printers have up to 50 dots/mm, print speed- 1000 characters/sec.
8. Scanners- devices for entering information into a computer directly from a paper document. You can enter texts, diagrams, drawings, graphs, photographs and other information. The file created by the scanner in the computer's memory is called a bitmap.
Scanners are:
black and white and color (number of transmitted colors from 256 to 65536);
manual move around the image manually, a small amount of information is entered in one pass (up to 105 mm), reading speed - 5-50mm/sec;
tablet- the scanning head moves relative to the original automatically, scan speed-2-10 sec per page;
roller- the original is automatically moved relative to the scanning head;
projection- resemble a photographic enlarger, at the bottom - a scanned document, at the top - a scanning head;
barcode scanners- devices for reading barcodes on goods in stores.
Resolution scanners from 75 to 1600 dpi.
9. Manipulators- computer devices controlled by the operator's hands:
mouse- a device for determining the relative coordinates (displacement relative to the previous position or direction) of the movement of the operator's hand. Relative coordinates are transferred to the computer and, with the help of a special program, can cause the cursor to move on the screen. Various types of sensors are used to track mouse movement. The most common is a mechanical one (a ball that is touched by several rollers), there is also an optical sensor that provides a higher accuracy of reading coordinates;
joystick - lever pointer - a device for entering the direction of movement of the operator's hand, they are more often used for games on a computer;
digitizer or digitizing tablet- a device for accurate input of graphic information (drawings, graphs, maps) into a computer. It consists of a flat panel (tablet) and a hand-held device associated with it - a pen. The operator guides the pen along the graph, while the absolute coordinates enter the computer.
10. Keyboard- a device for entering information into the computer's memory. A microcircuit is located inside, the keyboard is connected to the motherboard, pressing any key produces a signal (the character code in the ASCII system is the hexadecimal serial number of the character in the table), in the computer memory, a special program restores the appearance of the pressed character by code and transmits its image to the monitor .
The specific set of components included in a given computer is called its configuration. Minimum PC configuration necessary for its operation includes a system unit (there are MP, OP, ROM, hard disk drive, floppy disk drive), a keyboard (as an information input device) and a monitor (as an information output device).
Lecture 4. Software. Operating system.
Personal computers (PCs) are versatile information processing devices. PCs can perform any information processing actions. To do this, it is necessary to compose for him in a language he understands an exact and detailed sequence of instructions (i.e. program) how information should be processed. The computer itself does not have knowledge in any area of its application, all this knowledge is concentrated in the programs running on the computer. Therefore, the often used expression “computer did” means exactly that a program was executed on the PC that allowed the corresponding actions to be performed. By changing programs for a PC, you can turn it into a workplace for an accountant, designer, editor, artist, etc. Thus, for the effective use of a PC, it is necessary to know the purpose and properties of the programs needed when working with it. Consider the main types of programs.
Programs running on a PC can be divided into three categories:
System programs- programs and software systems that expand the capabilities of the basic software (SW) and organize a more convenient user environment, performing various auxiliary functions, for example, creating copies, issuing help information, checking the performance of PC devices, etc. System programs also include:
programs - drivers ;
programs - shells ;
programs - utilities ;
programs - packers ;
antiviral programs;
programs for diagnostics PC;
programs local network management etc.
Application programs (application software)- a program that solves the problem of the end user. Ancillary programs that are not part of the system software are also considered application programs. Recently, the term "application" has been used.
Tool systems (programming systems)– software products intended for software development. These include programming systems (MS Visual Studio, Borland C, etc.).
Shell- a program (complex of programs) that simplifies the user's work with OS commands, expands the set of basic and service functions, provides a more convenient and visual way to communicate with a PC, for example, Norton Commander.
Utility (from Latin utilitas - benefit)- utility programs that provide the user with a number of additional services (disk compressors, archivers, backup programs, anti-virus programs, etc.). For example:
utility defragmentation disk - designed to optimize disk operation and increase the speed of access to it, collects file fragments into one block;
program checks disk checks the correctness of the information contained in FAT, NTFS and other file allocation tables, searches for bad disk blocks; program seals disk is designed to create and maintain compacted (compressed) disks;
programs optimization disk change the location of files and directories to speed up access to them.
Archivers- programs that perform data archiving - packing files by compressing the information stored in them. Compression of information in files is performed in various ways by eliminating redundancy. The degree of compression depends on the program used, the type of data being compressed, the compression method and is characterized by the coefficient Kc, defined as the ratio of the volume of the compressed file Vc to the volume of the original file Vo, expressed as a percentage. The most popular are ZIP, CAB, ARJ, PKPAK, LHA, ICE developed abroad, as well as AIN and RAR developed in Russia. Usually packing and unpacking is done by the same program. Currently, WinRar and WinZip archivers are widely used.
System software
Basic software- a minimum set of software tools that ensure the operation of a computer (operating system, operating shells - text and graphic).
Software that enables users to work with a computer and facilitates this work. The main part of the system software is the operating system (OS).
Operating system – a set of programs for controlling and coordinating all computer devices, managing the process of executing application programs and providing a dialogue with the user. The OS provides control of the computer as a whole, its interaction with the environment (human, application programs, other systems). Examples: MS DOS, MS Windows, Unix/Linux, etc.
The OS is the main piece of software, controlled by commands.
Operating environment- a fully functional add-on for the operating system.
Maintenance systems- a set of PC software and hardware for detecting failures in the process of computer operation.
Operating systems are tied to the processors on which computers are developed. For IBM-compatible computers, a distinction is made between:
single-tasking(MS-DOS, PC-DOS, PTS-DOS, Windows);
multitasking (multitasking- the mode of simultaneous solution of several tasks. A task- part of the work performed by a computer);
Network- ensuring network operation. Key features: messaging management, data protection from unauthorized access, directory management, e-mail (Lan Server, Windows NT, NetWare);
Operating systems providing real-time mode- OS with a guaranteed response time to an event, for example, in process control systems: nuclear power plants, chemical plants, etc. (QNX from Quantum SoftWare Systems Ltd).
Windows 3.x used the so-called corporate method to share processor time between programs, in which the responsibility for multitasking lay with the application programs themselves. They themselves had to report when a particular device is freed.
Windows NT and OS / 2 use preemptive multitasking, in which the system sets a certain period of time after which a forced program switch occurs (UNIX, OS / 2, Windows "95 and older).
True multitasking can only happen on multiprocessor systems.
Problem-oriented application packages (APPs) (divided by types of subject areas, information systems, functions and task complexes) are narrowly focused on solving certain problems.
Computer-aided design software (to support the work of designers and technologists - the development of drawings, diagrams, diagrams, etc.).
A general-purpose application software supports end-user information technologies (database management systems, DBMS, report generators, word processors, spreadsheets, presentation graphics tools, integrated packages),
Integrated PPP - a set of functionally different software modules that can interact with each other by exchanging data through a single user interface (processing text, numeric and graphic data in one software package).
Office PPPs provide organizational management of office activities (organizers - for planning working time, etc., translation programs, communication PPPs - user interaction with remote subscribers or information resources).
Publishing systems.
multimedia software.
Artificial intelligence systems.
OS features:
1. Organization of the coordinated execution of all processes in the computer.
2. Ensuring the storage of information in external memory and exchange with input-output devices, i.e. The OS is responsible for the correct input of information from the input device and its output to the monitor, printer, etc., as well as for the correct distribution of information on external memory disks.
3. Reaction to errors and emergencies.
4. Implementation of dialogue and communication with the user.
The operating system is a fairly complex organized program, and it would be more appropriate to speak of it as a whole complex of programs.
Operating system structure:
Core- translates commands from the language of programs into the language of "machine codes", understandable to the computer.
Drivers- Programs that control devices.
Interface- a shell with which the user communicates with the computer.
Windows operating system.
The OS we work with is called Windows.
This OS got its name due to the fact that the main means of communication with the user in it are various types of windows (“window” in English. “Windows”).
Programs that run on Windows are called applications.
Some principles of Windows OS:
1. Windows “knows how” to work with all modern and less used devices and programs. These devices are connected automatically.
2. Another advantage of this OS is a unified user interface (method of communication), thanks to which the same principles for managing their work are preserved in various programs, and you can perform operations in several ways, among which you can choose the most convenient one.
3. A single software interface allows you to create information in some applications and transfer it to others.
4. The next principle embedded in Windows is the principle by which the same image is formed on the printer as on the monitor screen (What You See Is What You Get).
OS boot steps:
Turning on or starting a computer is the most crucial moment of its work. First of all, you need to load the OS into RAM.
1. The PC receives its first command from the ROM - microcircuits located on the motherboard are powered by a battery, and therefore the programs recorded in it are not erased after the computer is turned off.
It is in the ROM that the processor accesses at the moment of switching on and does it always and automatically.
The ROM contains BIOS testing programs for the computer.
The operation of the BIOS is displayed on the screen with white running lines. At this moment, the PC checks its devices - RAM, hard disk and drives of other disks, the presence of a keyboard and other devices.
If something does not work, the BIOS reports a malfunction, otherwise it finishes its work and gives the command to load a special program from the hard disk into RAM.
2. This program is located in a special boot sector of the disk and is called Master Boot (OS loader).
It is very small and its main purpose is to read the operating system from the system disk into RAM.
If there are no system disks in the PC, the message Non system disk appears on the monitor screen and the OS loading stops, the PC remains inoperative.
If everything is in order, the bootloader reads the OS from the disk into RAM.
After the OS is loaded, control is transferred to the command processor and a graphical interface appears on the screen. From now on, everything that we do with a computer takes place under the control of the operating system.
The utility suite contains the Windows operating system itself. To work with disks and files, Scandisk and Defrag are used.
scandisk allows you to check the integrity of the file system and disks, and Defrag optimizes the placement of files on disks.
Partitioning a hard drive into logical drives (partitions) possible with the program Partition Magic . It is advisable to run the program from a floppy disk in DOS mode, which can be accessed by pressing the F8 key when Windows boots up (the DOS exit menu will appear). Partition Magic can "repartition" a drive without losing data even after installing the software on the computer.
Registry – operating system database containing configuration information. Physically, all registry information is divided into several files. The registries of different versions of Windows are slightly different. In Windows 95/98, the registry is contained in two files, system.dat and user.dat, located in the Windows directory. Windows Me has added another classes.dat file.
The data in the registry changes when you install new hardware, install and run programs, and in a number of other cases. During the operation of spyware, conflict between different programs, incorrect removal of software, incorrect changes to data in the registry are possible. This can lead to failures in Windows and, at best, the information will have to be restored from a backup. The main tool for viewing and editing registry entries is the Registry Editor program, which is included with Windows. To launch it, press Start on the Windows taskbar and in the menu Run dial a team regedit. The program window will open, in which the registry tree is displayed on the left, similar in appearance to the display of the disk structure in Explorer, and the keys contained in the selected partition are displayed on the right. With the help of the editor you can edit values, import or export the registry, search. The final element of the registry tree are keys or parameters divided into three types: string, binary, and Dword (occupies 4 bytes).
Windows Customization Editors
Windows setup is usually carried out using the Control Panel, called from the menu Start > Control Panel. A number of settings are located in the Tools menu in the System Information window (to access it, click Start > Programs > Accessories > System Information > System Information).
Utilities:
Disk Defragmenter.
Disk cleanup.
Assignment of tasks.
Disk check.
On the role of computer technology in modern society (interview with Marchuk G.I.)
A. Lepikhov
Interview about the role of computer technology in modern society in the late 1980s by Academician G.I. Marchuk gave the journalist A. Lepikhov. In a manner characteristic of Gury Ivanovich, the role of computers in the modern world is accessible and clearly shown: science, production, economics, the social sphere, etc. This interview has not lost its relevance today, and in some cases has increased the drama associated with the use computers, the place and role of information technology specialists in society. He speaks of a new reality in which it is necessary to teach schoolchildren differently, rebuild the entire system of higher education, change the nature of the training and retraining of technicians and workers, and teach the management of enterprises to effectively use electronic technology.
- We live in a time when electronic computing technology begins to literally permeate all spheres of human activity - from big science to automatic children's games. And, as it always happens with the active intrusion into our lives of something fundamentally new, the process of "computer expansion", of course, requires reflection. First of all, the question arises: what was the motive for the development of computer technology?
- G.M.: The need to solve more and more complex problems of science, technology, economics, the desire to express qualitative ideas quantitatively. This applies to all sciences: geography and geology, medicine and sociology... Not to mention the needs of engineers and designers, who, earlier than many, began to feel the lack of computing facilities.
As is well known to specialists, the principles of electronic computing were formulated over a hundred years ago, and even earlier there was a theoretical basis for building a computer - Boolean algebra, named after the English mathematician George Boole, one of the founders of mathematical logic. However, these achievements were forgotten for many decades, because people completely managed with the simplest methods of counting and technical devices that were elementary for this purpose. In a word, it is far from being an isolated case when the discovery was ahead of its time and did not immediately receive proper recognition.
What we call electronic computing technology was born in the 40s of the XX century. The first computer ENIAC (electronic digital integrator and calculator) was "involved" in compiling ballistic tables. A powerful impetus to the progress of computers was given by work in the field of nuclear physics, and space research confirmed their outstanding importance. Solid allocations have dramatically expanded the scope of electronic computers, and applications with obvious benefits.
The industrially advanced countries stimulated a kind of “autocatalysis” of computers: society invested ever larger sums in the improvement of computer technology, its use brought additional profit, part of which went to the further development of the same computer technology.
Let's turn over the individual pages of the history of domestic computers. The first author's certificate in the USSR for the invention of a programmed automatic computer was issued in 1948. Following that, on December 25, 1951, at the Institute of Electrical Engineering of the Academy of Sciences of the Ukrainian SSR, a (small electronic calculating machine) was put into operation - the first in our country, developed under the guidance of an academician. The unit occupied an area of 50 square meters, contained over 6 thousand lamps, which consumed 25 kilowatts of electricity. MESM could perform arithmetic operations on five-six-digit numbers at a speed of ... 50 operations per second. But then it seemed fantastic because it was about 1.5 thousand times higher than the “calculating abilities” of a person. (It is still more correct to consider the computer of I.S. Bruk as the first Soviet computer. - approx. E. Proidakov).
Another brainchild of Soviet scientists, which appeared in 1953, - -1 (high-speed electronic calculating machine). She could already count almost 200 times faster and at that time was one of the fastest in the world. BESM made it possible to solve a number of problems that specialists did not undertake due to the huge amount of calculations.
Among the Soviet scientists who contributed to the progress of electronic computing, it is necessary to name the academician, president of the Academy of Sciences from 1961 to 1975, and the founder of the Siberian Branch of the USSR Academy of Sciences, academician.
The development of various branches of technology strengthened the base and capabilities of electronics, which naturally affected the computer. Switching from lamps to semiconductors, and then to integrated circuits, computers won in speed, found more and more new areas of application.
Computers based on simple integrated circuits manage to cope with hundreds of thousands of operations in a second. Computers based on large integrated circuits are ten times faster than their predecessors. And now computers on ultra-large integrated circuits are declaring themselves. Their speed is tens and hundreds of millions of operations per second.
To the uninitiated, the numbers are staggering. Meanwhile, this is far from the limit. The comprehensive program of scientific and technological progress of the CMEA member countries provides as a top priority for the creation of computers that will perform 10 billion operations per second.
Of course, all the current and predicted achievements of electronics are impossible without mastering the production of ultrapure metals, special alloys and artificial crystals, without success in laser technology, in many areas of applied sciences. Another thing is also clear: without the help of computers, the qualitative leap observed today in various spheres of human activity would be simply unthinkable.
And further. At some point, computers - through new projects that embody deep physical ideas - were forced to develop new, efficient electronic elements and circuits. The interaction has gone so far that the computer itself, on the basis of automatic design systems, is already creating variants of the components of the next electronic computers. This is especially well seen in the example of microelectronics, when a computer microprocessor fits on a crystal with an area of less than one square centimeter. Here, the design and manufacture of microcomputers are essentially combined into one cycle.
And all this happened in 35-40 years, before the eyes of one generation of researchers.
- What you are talking about is perceived as something distant.
- G.M.: Then we will resort to comparisons. The thickness of a human hair is about 100 microns. Now imagine fitting a grid of 400 transistors, each consisting of 1-micron lines, on a silicon crystal the size of your hair. Now compress these lines to half a micron. Almost 1.5 thousand semiconductor transistors can already be placed on the same area. Let's repeat the compression operation. At a thickness of a quarter of a micron, each semiconductor transistor would be the size of a large virus, and the cross-sectional area of a human hair would be enough for 4,500 such transistors.
This is not an exercise in abstract actions at all, but a reality that designers of modern computers face. The first integrated circuits, or, as experts say, "chips", with lines one micron thick, enter the world market. They contain over a million transistors. Chips with elements of half a micron - 4 million transistors can be placed here - are now being tested in laboratories and will “become streamlined” in the coming years. Quarter-micron chips (tens of millions of transistors) are likely to come into use sometime towards the end of this century. And at the very end of the century, according to available estimates, we may have in our hands the so-called "gigabit integrated circuits", that is, with a billion components each.
Not so long ago, the micron was considered the limit for semiconductors on silicon chips. However, the barrier, as we can see, has been overcome by engineers who have already become well accustomed to the world of ultramicrominiaturization. Complex structures are created, sometimes approaching the size of a molecule - so tiny that they cannot be seen even with powerful optical microscopes.
At the same time, chips with elements smaller than a micron are revolutionizing the way they are made. First of all, it is required to fully automate production, because the presence of a person can lead to the fact that the technological process will not be clean enough. If anyone has ever been to semiconductor factories, he will agree that few places are cleaner than such factories. Since the slightest speck of dust threatens to ruin the chip, the workers wear white overalls and sterile masks like surgeons. The air in industrial premises is constantly filtered, and in its cubic centimeter there are a thousand times less dust particles than in a hospital operating room.
And yet, for submicron chips, traditional semiconductor factories are hopelessly dirty.
The number of dust particles in a cubic centimeter must be reduced another hundred times. This is real if people are removed from the production premises altogether. But sterility is not the only factor. The tasks of designing, testing and printing integrated circuits are rapidly exceeding human capabilities. A person is simply not able to "pack" four million devices on a tiny silicon plate. This can only be done by computer-controlled machines.
I don't think I'm wrong if I say that sometime in the mid-1990s, only one integrated circuit will be able to compete with today's computers. And it will certainly cost extraordinarily cheap. Everything that is being done now, the most sophisticated of the existing ways of using chips, is only a small step towards what awaits us in 10-20 years.
- One often hears from computer specialists: they say, every time the cost of computer technology decreased abruptly, the face of the world changed.
- G.M.: This statement, of course, is too categorical and ambitious. But it is impossible not to admit that the rapid improvement of the computer element base is already prompting designers to seriously think about what a few years ago belonged to the realm of fantasy.
First of all, huge opportunities for modern computers open up in factory workshops, where systems are being introduced that can skillfully “manage” technological processes of any complexity and provide such control over the quality of products that a person simply cannot do.
Or take, for example, cars. How many of them are there in the world? Tens and tens of millions. Microprocessors here will help to properly operate the engine, reduce exhaust emissions, reduce fuel consumption, and avoid accidental collisions on the roads.
Superchips, or ultra-large integrated circuits, will no doubt revolutionize television as well. The transmission of signals in digital form - a method that is cheap precisely in the presence of superchips - allows you to get an image that is much superior in quality to its current one. Perhaps, in models of such TVs there will be only two or three superchips. Undoubtedly, there will also be televisions with storage devices. Favorite films, performances, performances of popular artists can be played at any time by sending the appropriate command to the home computer. The cost of such video devices is still very high, but they will become available to everyone when four-megabit chips "come into use".
Remember the first electronic wristwatch. The very idea that a traditional mechanism worked out over the centuries can be replaced by something amazed the minds. And now electronic watches are so commonplace that they successfully compete in price with mechanical ones.
- Your last example is just an excuse to return from the future to the present. Hence the next question: what are today's electronic computers and what is the general scope of their application?
- G.M.: Indeed, the current "spectrum" of computers is very wide - from supercomputers to microprocessors. Conventionally, three main lines of computers are distinguished: large machines with a speed of millions of operations per second, minicomputers with a speed of hundreds of thousands of operations per second, and microcomputers with a speed of tens, and sometimes hundreds of thousands of operations per second.
Any of the computers is equipped with arithmetic and logical processors, operational and long-term memory, control and input-output information devices. Long-term memory is usually stored on magnetic disks, tapes, or special media. It is long-term memory that is the focus of the programs necessary for calculations, and all the material that makes up the database.
Our lives include supercomputers with a performance of hundreds of millions of operations per second. As a rule, they are needed for research purposes or management of very complex scientific and technical complexes. On the basis of these machines, in particular, systems for collective use are also given. We are talking about systems of application programs organized into packages according to areas of application. This can be a package of linear algebra problems, statistical processing of experimental results, a package for displaying information in the form of graphs, etc. It is essential that most packages are universal, that is, they do not depend on the nature of a particular problem. In other words, if in the course of solving a problem it becomes necessary to process statistical data or, say, display information on a graph, then this does not require new programs - rather universal packages.
Many service packages are embedded in the memory of the machine; work is much facilitated and the productivity of the computer user's activity is increased, which means that an additional national economic effect can be achieved at this expense. And although it is not easy to evaluate it, it is, of course, proportional to the increase in the productivity of those who work with the help of computers.
Creation of computers that serve subscribers in various modes of access to them (remote batch processing, time sharing mode, "human-machine" dialogue, etc.), improvement of peripheral equipment and terminals - terminal devices as part of a computing system intended for input and the output of information during the interaction of a person with a computer (in this capacity, for example, displays, teletypes are used), the improvement of information transmission lines has significantly expanded their capabilities. This made it possible to move from local computing centers, the equipment of which is located in one place, to multi-machine complexes, the components of which are located at considerable distances from each other. The latter were called "networks of computers", "networks of computers", "networks of computer centers".
Computer networks are the best way to ensure the work of users in the case when there is a shortage of computer time at some points, and an excess at others. In addition, the computer network opens up access to huge databases of not only universal, but also specialized nature, helps the user to find "pieces" of already well-functioning programs and other valuable information in these databases, and dramatically speed up the solution of his task.
-What about minicomputers?
- G.M.: They are mainly used to provide automated control - both in production (ACS) and technological processes (APCS), in scientific research, education systems and many other areas.
In the first case, the computer is responsible for the analysis of the implementation of plans, the calculation of salaries and material and technical resources, the development of network schedules for the preparation of production, the assessment of jobs, and many other functions. The presence of ACS is a guarantee that the manager at any time has comprehensive information about the activities of his enterprise and can reasonably take the necessary organizational and economic measures. In fact, modern production is a complex organism with a large number of forward and backward links. It is the duty of both the director and, of course, of all management links to find states of this organism that are stable with respect to small deviations and that optimal variant that leads to the highest economic effect. Naturally, such an effect is associated with certain restrictions that are characteristic of a real production environment.
Speaking about process control systems, it should be noted that their role is very large in the production itself, because each system is intended for the integrated automation of a specific technological process. This is where the mini-computer is indispensable, and with a certain reason we can assume that the high economic effect from the introduction of process control systems is achieved precisely as a result of the use of electronic computing technology.
Process control systems have existed, perhaps, since the assembly line was created. But the traditional ability to control an assembly line or a rigidly built production was limited. And only new means of computer technology, including microprocessor technology, made it possible to control, say, the course of a technological operation on the basis of constantly incoming and processed information. This happens in much the same way as if dozens of controllers were vigilantly carrying out their service and, if any deviations from the technology norm were detected, they would immediately be eliminated. In fact, this is done by an automated control system. Information is continuously received from a set of sensors and analyzed on high-speed computers. In their memory are numerous options for disrupting the production process and a list of what needs to be done to correct the situation. The computer, in accordance with the program, "finds" the desired command and sends it to the actuators to make the necessary adjustments.
I will give just a few examples.
The rolling mill must roll a sheet of a given thickness. Previously put up with some tolerances. They were inevitable due to the heterogeneity of the source material, the uneven dynamic and static effects. As a result, interest, and even ten percent of the valuable metal was spent in vain.
Modern rolling mills are equipped with sensors connected to a computer. Some discrepancy with the established standard is found - the computer gives a command for re-rolling, and the sheet is brought to the desired thickness.
If the mill is continuous, working in one direction, then the computer “orders” the next roll to increase the pressure in the stand and again controls the thickness of the steel sheet in order to make the next operational decision. With such rolling, tolerances are practically eliminated and the metal is entirely used.
Saving material resources is an important task. But it is equally important to produce products that meet the highest technical requirements. For example, we melt iron. Only a very experienced specialist, as they say, feels the quality and readiness of melting. Of course, samples are taken, an express analysis is carried out, but its results sometimes come from the laboratory too late, nothing can be corrected. And in the end - substandard cast iron. If, however, we switch to a process control system, when spectral analysis is continuously carried out, the concentrations of all melt components are recorded, and these data are processed on a computer, then blast furnace production will become as manageable as a rolling mill. There will be huge savings due to additional volumes of high-quality pig iron. Although such systems are still undergoing pilot testing, it is already clear that their payback period is certainly less than a year.
The creation of more and more new process control systems is the main way for the development of an intensive economy.
By the way, more about the importance of mini-computers. Today, a more general concept of combining production control automation and process control automation has already been formed. Here we come to a single system based on the so-called integrated automated control systems. The possibility of optimizing organizational and purely technical measures, which such a system provides, promises brilliant prospects.
- And now, please, in more detail - about microprocessors.
- G.M.: This computer technology is built into the nodes of machines, devices and elements. Each microprocessor controls its node. But it can be connected to other parts of the machine through other microprocessors. Coordinates their actions, as a rule, a single mini-computer. This structure comes from the logic of managing large systems, for example, enterprises themselves. After all, they are built according to a hierarchical principle: first, sections, then workshops, then entire production facilities, and finally, the directorate.
Microprocessors have already taken a strong place in the machine tool industry - in machine tools with numerical control (CNC). This is a new and active area of application of microprocessor technology in production. At the same time, the most radical step towards integrated automation: from the control of one machine with a limited set of operations to unmanned robotic production complexes.
I would like to emphasize the main thing: the great possibilities that the introduction of computers opens up for achieving a national economic effect. It develops due to the optimal organization of production and its components, making timely adjustments to the technological process in case of random deviations, reliable operation without the presence of a highly skilled worker.
If we return to household appliances, even now we already feel the influence of electronics in general and microprocessors in particular on our life. Washing machines with a programmable set of operations, a wide variety of calculators, video recorders and much more are on sale. The pace of intellectualization of household appliances is undoubtedly increasing. This means that the household will take less labor, from which, again, social production will benefit.
- Today there is a lot of talk about the fact that it is practically impossible to carry out scientific research without electronic computing technology, perhaps, except for the most abstract areas associated with purely theoretical developments. How exactly do computers help scientists, where is their application needed in the first place?
- G.M.: First of all, of course, in mathematical modeling. Indeed, scientific research usually begins with hypotheses. On their foundation, more and more detailed models of the phenomena under study are built, which are usually implemented on a computer. Possessing high speed and memory, a computer on the basis of one or another model repeatedly solves the problem with the most diverse sets of input parameters given to it. And this allows us to quantitatively describe the possible solutions to this problem, to choose from them those that are of interest to the researcher. And do it in a fairly short amount of time. Equipping laboratories with electronic computers is a reliable way to increase the pace of scientific research.
Further. The outstanding achievements of recent years, such as the creation of artificial genes, the production of feed protein from methane, the emergence of large and extra-large integrated circuits, could not become a reality without computer technology, which helped to conduct relevant experiments. Computers controlled all stages of the experiment and, if it deviated from the given program, they immediately sent a corrective command.
Electronic computing technology is also indispensable in processing the results of experiments. If in the pre-computer era complex experiments lasted for days, or even weeks, then the processing of their results dragged on for months, or even years. The computer today gives the answer almost immediately after the end of the experiment. The time savings is truly enormous. It can be said with certainty that computers have increased the productivity of researchers by more than 10 times.
The logic of modern scientific research is such that it requires the approach of a computer to a scientist - be it a theoretician or an experimenter. As for experimenters, a certain trend has already appeared here: they are quite satisfied with standard minicomputers, since the nature of the use of these machines differs little from their use in process control systems.
With theorists, the situation is more complicated. They need the whole computer to work, albeit not so fast, but with all its capabilities. The time-sharing mode on mainframe computers solves this problem, but it solves only partially. After all, a scientist thinks, constantly referring to new information; sometimes he needs to intervene in the course of calculations or change them. However, it is impossible to attract a large computer for such purposes - its time and resources are very expensive.
There is a contradiction between the needs of the researcher and the capabilities of computers. It was overcome when a new original direction was born in computer technology - individual, or, as they say now, personal computers. These are quite modern machines with their characteristic architecture, a set of appropriate equipment and programs. Work on a personal computer is carried out using 16- and 32-bit words. 64-bit arithmetic is not excluded, of course, with some loss of computational speed. A personal computer has input-output devices and, if necessary, communication lines with other computers. That is, if the “capabilities” of a personal computer are not enough to solve the problem that has arisen, then the finished program can be transferred via the communications system to another machine with large resources in order to receive an “answer” later.
- You spoke about the participation of computers in the activities of scientists. But a scientific idea is embodied, so to speak, in a "real product" usually only through design and development. After all, as often happens: a scientific idea has long won universal recognition, and years of painstaking work of design engineers pass before its optimal or simply effective implementation in the national economy. Is this distance shrinking?
- G.M.: The real opportunity to reduce the time "from idea to machine" arose after the advent of CAD - automatic design systems. I will not talk about the historical path that they have traveled, although in itself it is interesting and instructive, but I will only talk about their basic principles.
What is the modern system of design work? It consists of three interrelated steps. The first is the formation of the terms of reference for the project: a human-machine dialogue for drawing up a schematic diagram. Naturally, the project should be based on the most modern scientific ideas, take into account the possibilities of implementation, restrictions on the required resources. These are, so to speak, "discussions" between a person and a computer, in whose memory all the necessary information is stored - from theoretical models to all sorts of restrictions. The final result of the first stage is the "outline" of the project.
Then comes the time of its detailed design study. At the second stage, application packages focused on the problems of this project are widely used. This operation, if necessary, is combined with a system for finding the best solutions based on the experience of the researcher. As a result, a complete set of design documentation and its graphical display appears.
And finally, a project is being created for the technological preparation of production for the production of serial products.
But it happens that the idea of the car is good, and the design development is quite solid, but it is impossible to produce mass-produced products for one reason or another. Then the so-called iterative design process begins - taking into account the constraints dictated by production. Sometimes this affects the fundamental aspects of the project, and everything seems to be repeated again - from the level of completion, or even the secondary study of the technical task. And so on until the desired result.
It is clear that the presence of a computer sharply reduces the time required to pass through the three indicated stages. And the sooner a scientific idea is embodied in a new machine or technology, the greater the economic effect will be received by the national economy. But the benefits of using computers are far from exhausted.
The automatic design system for machine tools, machining centers or color TVs is the fruit of the intense efforts of scientists, designers, technologists and programmers. After all, first you need application software packages that are designed to speed up design work. Then the same packages can serve well in all design bureaus and in enterprises where new technology is born. Compared to the traditional way, when each team acted in its own way, the gain is enormous. Previously, the project took years, now - weeks and even days.
It is true that software packages for CAD, brought to the appropriate standards, are quite labor-intensive and turn out to be very expensive so far. But, once having arisen, they are able to satisfy any designers and technologists, providing them with huge arrays of programmed knowledge. Application software packages are becoming our national treasure. And it is not surprising that since 1983 they and other computer software have been considered commercial products in our country. This is an important step in stimulating the development of computer software by economic means.
- Today, the volume of the most diverse information - scientific, economic, technological, social - is growing literally like a snowball, and it is already difficult to navigate in the information ocean without the help of a computer. How is this done in practice?
- G.M.: Electronic computers are widely used in the field of information - from the creation of databases to the organization of effective search engines.
We started with streamlining the most complex information flows, with combining a vast mass of information into special sections, subsections and paragraphs. All of them have consistent indexing, and the computer can move from large arrays of homogeneous information to smaller and smaller ones. As a result, by continuously narrowing the search circle, the machine reaches its goal - it finds what the user is interested in.
Databases of different nature - many hundreds and even thousands. Collecting them all together, into a single computing system, is simply unrealistic. Indeed, let's take at least three databases - about synthesized organic compounds, about the patient's immune status, and about the composition and characteristics of stars in the Galaxy. Of course, these data have something in common, but the very subject information of such databases, the areas and methods of their use are completely different. On the one hand, they cannot be "torn off" from the staff of research institutes, clinics, observatories, libraries - without them, they will soon lose their freshness, and hence their value. On the other hand, and this is natural, it is necessary to make any database available to all users. In other words, they must be combined. Where is the way out of the existing contradiction? It was found in the organization of a distributed knowledge system.
Indeed, why try to combine the incompatible? It is much better to give each team of researchers a computer, albeit a small one with a sufficiently capacious memory, to create their own standard-structured base. The "owners" of this database will constantly develop and update it - after all, we are talking about information that is vital for them. A user from any other institution, "entering" this database through communication channels, acquires the latest and most qualified information. That is, one team is able to provide relevant information to the entire country. All such specialized information sources make up a distributed knowledge system. If now they are combined with each other, then we will come to a single system of data banks of the country. This is the main way of development of modern information technology.
Now, for example, the Institute of Organic Chemistry of the Siberian Branch of the USSR Academy of Sciences, upon teletype request of any user, can give an answer about whether a chemical compound with the indicated parameters was previously obtained or not. But the number of chemical compounds, if I am not mistaken, increases annually by about two to three tens of thousands. Is it necessary to explain once again how much such an "electronic certificate" saves the organic chemist's time, saves him from rediscovering already synthesized substances.
Or the design work we just talked about. Any new machine or technical device must at least correspond to the world level. But this world level needs to be constantly “monitored”, promptly entering fresh information coming from different countries into data banks. We are talking here about tens and hundreds of thousands of types of products.
Society will become more and more computerized. First, fundamental constants, then technical data systems, and, finally, semantic texts as the most complex type of information - these are the stages in the formation of a single information network in our country. However, this is only the beginning of the journey. Ahead is a huge and most interesting work on the use of knowledge accumulated by man and systematized with the help of electronic computing technology.
- It is well known that computers are capable of solving the most complex problems of science and technology. On the instructions of the researcher, in the process of answering, she goes through numerous options and stops at the best of them. But after all, a computer usually operates according to a clearly formulated program. The same search for the optimal solution and the enumeration system were proposed to her by a person. But do modern electronic machines have their own intelligence?
- G.M.: Already at the first stage of the development of computers, people began to teach them to "think" and draw at least elementary, but quite logical conclusions. True, the boundaries between a fully programmed computer system and its “initiative” are very arbitrary, but, so to speak, there is still a “programmed initiative”.
Creating more and more perfect programming languages, a person strives to write down the conditions of the problem in a form close to natural language. For example, he instructs the machine to calculate the wing of an aircraft of such and such a shape, surface quality and size, taking into account certain airflow velocities. The computer, according to the information received, must accurately, down to the smallest detail, compose a mathematical problem. More recently, this was done by a software engineer. The existing systems for displaying the initial conditions of the problem are such that the computer copes with them no worse. And most importantly - in a matter of minutes or hours, in contrast to the weeks and months that a specialist armed with knowledge and intelligence needs. It's just that modern machines have "learned" to choose rational or even optimal intermediate operations. And this means that they are capable of making decisions when various options for the software implementation of calculations are possible. Here, at the level of the corresponding machine languages and translators - ways of translating a language into machine instructions, we first met with the artificial intelligence of a computer.
However, as soon as computers began to be used in design work, to build automated systems for managing databases or technological processes, researchers had the idea to introduce creative elements into the software. Let's say a designer starts designing a machine part on a display. He needs to know the dimensions of the part, as well as the input and output characteristics - after all, the part must fit the future car. Control over the observance of these indispensable conditions rests with the computer. If they are violated in the design search, then the computer immediately lets the person know about it. She acts as an experienced assistant or expert. This is again an element of artificial intelligence.
For a part from the database, you need to select a material of the required strength, with certain temperature parameters, etc. On request, the computer finds the required sets of materials and offers them to the person. The designer, guided by his experience, gives the computer the task, given the known characteristics of the selected material, to calculate the strength, temperature and other fields of the part. If the results of the calculation satisfy him, the work is completed and the part is ready. If not, then he chooses another suitable material, and everything repeats again. As you can see, the designer and the computer come into contact in an interactive mode, and everything that the assistants had to do, using reference books and the corresponding calculation schemes, is done by the computer. It now replaces man not only in the performance of mechanical work, but also in logical conclusions.
It is where logic and logical conclusions begin that the manifestation of artificial intelligence begins. A person gradually transfers more and more of his functions as a designer-researcher to a machine, leaving behind only the most fundamental ones, where creativity and unprogrammed knowledge cannot be dispensed with.
The modeling of intelligence occupies a special place in the development of modern science. I am not talking, for example, about the derivation of new mathematical theorems, although here much has already been achieved with the help of the algebra of logic, in particular, the Leningrad school of Professor N.A. Shanin, who achieved outstanding results in proving theorems in set theory. Let's take simpler things. We are all taught in school to solve geometric and trigonometric problems. But the same can be "learned" and computers. So if a scientist later encounters a problem from Euclidean geometry in the course of his research, it will be immediately solved by the machine.
Further. In mathematics, and especially in computational mathematics, many universal and specialized algorithms for solving problems related to linear algebra, differential and integral equations have been worked out today. Of these, it is also realistic to build databases and search engines to select algorithms with the help of which the problem will be solved by the computer in the best way. And this is an element of artificial intelligence.
Exact integration, differentiation, expansion of functions into series is also becoming a sphere that a person is already transferring to electronic computing technology.
The means of intellectualization of solving problems on a computer and the main models will be developed in the foreseeable future on the basis of a dialogue between man and machine. It is in the cooperation of the higher human intellect, which cannot be fully described, and the increasingly improved elements of the artificial intelligence of the computer with its uniquely fast enumeration of data arrays, the necessary information and the search for various optimizations - the prospect of using electronic computers.
In the meantime, a much more modest goal is on the agenda: to teach computers to understand us at the level of a simple, but natural language; give advice to a person who is not dedicated to the subtleties of algorithms for solving complex problems; find the best solutions; reflect volumetric information in the form of graphs and holograms; answer us with synthesized speech.
This is far from complete, but the main list of artificial intelligence problems that a person endows with a computer. Allocates to increase the pace of scientific research, the speed and quality of design work, for information support and management of production processes. If we add to this the active use of computers in medicine, banking, trade, transport and many other areas, then we will see a truly endless horizon for the use of computers. The limit of their applicability today can only be set by our imagination.
- How will an industrially developed society look like with the mass introduction of the achievements of electronic computing technology? Where will the changes caused by the computer be most noticeable?
- G.M.: First of all, in social production. The content of labor itself will change and its productivity will increase tenfold.
Modern serial production is based on the division of labor, on the performance of specialized operations that do not require special skills, and computers greatly increase the possibilities of its complete automation, eliminating repetitive, monotonous, tedious operations for a person. So these kinds of jobs will disappear in industrial enterprises in the first place. But not only them. Today, many factories already operate CNC machines or even special machining centers. However, we must not forget that with their appearance, the nature of the duties of a skilled worker-machine operator has changed. He now only watches the automated equipment. The figure of a virtuoso turner is a thing of the past. And vice versa, there is a growing need for highly qualified specialties - for engineers for the operation of microelectronic equipment, software experts.
In the next century - and before it comes, most industrial jobs will look very different. They will be occupied by robots that can "see", "hear", "touch", react to ultraviolet, infrared or radioactive radiation, self-program and reprogram. The first fully automated enterprises are already being created, where there is practically no living human labor. Automatic machines that do not know rest 24 hours a day, with productivity immeasurably higher than that of a person, and besides, “reproducing” themselves, is a close reality.
And you need to be prepared for this reality. It is necessary to teach schoolchildren in a different way (the reform of the secondary general education school is already underway), to rebuild the entire system of higher education, to change the nature of the training and retraining of technicians and workers, to teach the heads of enterprises to use electronic technology effectively.
Science, technology, production, scientific and technological progress in general require that the focus of attention in the training of specialists of all categories should move from the simple assimilation of large amounts of information to its creative assimilation, the perception of continuously changing ideas, new trends in modern development.
The very appearance of computers gives a powerful impetus to the creation of such teaching methods in schools, technical schools and universities that would enhance the creative abilities of a person armed with computer technology.
In a word, everyone needs to change their usual methods of work and go back to study. Learn to live and work in a new, rapidly changing world, which is unthinkable without the widest use of modern computing technology.
Ponarin O.S., Fedorova A.P., Brest, prepared the article for placement in the Virtual Museum.
From the book "Horizons of scientific search", Marchuk G.I. Publishing house "Soviet Russia", Moscow, 1987
17 February 2017
With the exception of only a small number of gifted people, mankind from time immemorial has looked at arithmetic calculations as a hard tedious job that must be got rid of at any cost and by any available means. The abacus (essentially a primitive manual digital computing device) has a long history and seems to have been invented independently in various parts of the world and is still in use in some places. After the end of the XVI century. logarithms were invented, the slide rule became an indispensable mechanical tool. The first slide rule appeared in the 20s of the 17th century. It made it possible to perform more complex calculations, although the analog nature of the instrument (numbers are represented by distances) greatly limits accuracy in many calculations. Nevertheless, the slide rule is still widely used by mathematicians, scientists and engineers around the world. There are also a number of specialized counting devices: tables of ready-made calculations in accounting, automatic scales in grocery and gastronomic stores, or meters at gas stations. All these devices use pre-prepared tables or scales that allow you to very quickly perform multiplication operations for various monetary calculations.
Such technical devices are now very widespread and serve as the simplest way to get rid of a large amount of simple but tedious arithmetic calculations. At a slightly higher level of sophistication are office adding machines and cash registers, which easily perform a large number of sequential additions and subtractions and print the results of the operations performed, as well as various subtotals and totals. Based on these relatively simple apparatuses, a variety of more advanced calculating machines have been developed.
The person who uses such a device may not have a complete understanding of how it works, but usually it is not difficult for him to understand that this is just a convenient mechanical device for more efficiently doing the work that he himself could do manually with a pencil and papers if he had enough time and could work tirelessly and never make a mistake.
Similar considerations apply to more complex desktop adding machines as well. These are mechanical digital devices designed to perform basic arithmetic operations (addition, subtraction, multiplication and division) and have a number of auxiliary devices for accumulating results and performing reduction operations. Cheaper adding machines are usually operated by hand and are used when the amount of computation is relatively small and also for teaching purposes. For very long calculations, when greater speed and flexibility are required, larger and more expensive calculating machines are needed. They are usually driven by an electric motor, although they are still mechanical in principle. Desktop computers of this general type have been in use for a very long time, and until very recently almost all scientific calculations of any complexity were performed with their help. The enormous advantages of desktop adding machines over manual calculation methods are well known. Numbers are entered into the machine quickly and accurately by turning knobs or pressing buttons; all arithmetic operations are performed within the machine itself; careful planning of the sequence of calculations can avoid recording a large number of intermediate results. Of course, errors can occur in calculations, although not as often as when working manually, so usually a series of operations to check the result is included in the calculation sequence.
The advent of desktop computing machines naturally expanded the range of possible calculations, but the time soon came when the natural speed limit of these machines was reached. It is easy to see that when performing a large sequence of calculations, for example, when summing a large number of products, the limiting factor is not so much the speed of the machine itself, but the time required to enter numbers into it, read and rewrite the results, and also decide on subsequent actions. So the end result is that the time required to solve a complex problem is reduced very little, even if the machine performs basic arithmetic almost instantaneously.
The more complex the job, the more operator fatigue will affect and the more likely errors will occur. In addition, if calculations of a certain type must be repeated many times, then the correct sequence of actions in one calculation does not guarantee that an error will not be made the next time. Another difficulty is that, in order to reduce time and improve accuracy in long calculations, it is usually advisable to entrust the main work to an experienced operator, although this means that the compiler of the problem must spend a lot of work preparing the work and the necessary explanations to the operator. And if the same mathematical method is used again for other data, then it may happen that all these explanations will have to be given again to another operator.
Although desktop adding machines represent a great improvement over other methods of calculation, their shortcomings are quite obvious, and therefore there was a strong case for the development of a completely different type of machine. An appropriate electronic circuit, using lamps or transistors and electrical circuits, certainly allows basic arithmetic operations to be performed much faster than purely mechanical devices. However, the benefits of these means cannot be enjoyed unless human intervention is kept to a minimum. This means that it is necessary not only to get rid of the slow writing, reading and transmission of numbers by a person, but it is necessary to somehow restructure the entire work plan so that the operator does not have to make any decisions in the process of calculations. It is in the solution of these problems, and not only in increasing the speed of internal operations, that the real revolution, caused by modern automatic electronic computers, consists.
Computers began to be developed at the end of World War II. The first machines that had the basic design features of modern computing devices were the EDSAC computer, which began operation in 1949 at the University of Cambridge, and the SEAC computer, manufactured by the US National Bureau of Standards in 1950. These first machines used vacuum tubes, which in have now been replaced by transistors, which made it possible to reduce the size of computers and have a much higher reliability. To date, great progress has been made in the field of microminiaturization of equipment. All this will make it possible to create desktop electronic computers and reduce the duration of basic operations to nanoseconds, which means thousands of millions of operations per second. A number of excellent manuals have now been published in which the reader can find a detailed description of existing machines and specific recommendations for working with them.
We will discuss here only the basic principles as they relate to the subject of this book.
Let us consider the most important properties of a modern electronic computer. First of all, it is important to understand that it still performs the same basic arithmetic operations as a desktop adding machine, and therefore does essentially the same thing that a person working only with paper and pencil can in principle do. The difference lies, on the one hand, in a huge increase in technical efficiency, and on the other hand, in the implementation of logical control over the sequence of operations. Therefore, understanding what a computer ultimately does is no more difficult than understanding the usual way of solving arithmetic problems. Whether an electronic computer is considered to exhibit signs of intelligence, or whether it is capable of performing work close to the functions of the brain, depends to a large extent on how we define these concepts. The most important thing is that the computing machine, however complex and perfect it may be, is essentially only one of very complex devices designed for specific purposes, and as such it should be considered in many respects in the same way that and any other complex scientific equipment, such as an electron microscope or a linear particle accelerator.
A conventional desktop adding machine is fed a pair of numbers to perform some arithmetic operation, such as addition, and these numbers can be stored thereafter the operation is completed. The machine may also store one or two more numbers, such as the number obtained by adding or multiplying several numbers, or the accumulated sum of the products. However, the total storage capacity rarely exceeds five or six numbers, and even in this case, the number of digits of numbers is extremely limited. An electronic computer has a corresponding electromagnetic device, which can store several thousand numbers (with a very large number of digits) in a form that allows for quick selection; a magnetic disk or magnetic tape can store several million numbers in a form that allows for relatively slow sampling (slow by electronic standards). This makes it possible to eliminate human intervention in the processing of intermediate results, as well as to automatically process a huge amount of numerical data. Since the data is recorded on punched cards, paper tape, magnetic disks or magnetic tape, they can be used repeatedly without the application of mental or visual effort on the part of a person; they simply go to the corresponding external reader of the computer.
But the most important thing is that it was possible to develop methods for planning the entire sequence of calculations. To do this, a program of instructions is entered into the computer, which is stored there along with the corresponding data. These commands are written in the corresponding numerical code and are primarily associated with the performance of basic arithmetic operations on pairs of numbers stored in certain parts of the storage device. Once the program and the necessary data are entered into the machine, then all other operations are carried out by the machine itself at a speed dependent on the electromagnetic circuit. The final results are either recorded on punched cards or paper tape, or fed directly to a teletype or other reproducing device. The program for any given sequence of calculations must be thought out very carefully. But once a program is written and properly tested, it can be reused without further verification. Clearly, this results in significant savings in time and labor. A properly tested program can be used thousands of times by many people working on different computers. No less important is the fact that a certain program may contain a command to repeat the execution of a particular task (for example, solving a certain system of equations) several hundred thousand times, each time using different data. Then part of the program should be devoted to solving one system of such equations. If this part of the program is compiled correctly, then within the limits of this program it can be accessed as often as desired with full confidence that each time the equations will be solved correctly. This eliminates one of the most important shortcomings of desktop computers, which was already mentioned above, namely, that the correct operation of a desktop computer in one case does not guarantee the absence of errors in repeated calculations.
Working on a desktop calculating machine, the operator watches the calculations being made at all stages. If anything unusual or unforeseen happens, he can immediately take the necessary measures and in this way avoid serious mistakes. The use of electronic computers is often objected to on the grounds that there is the possibility of a very large number of unnoticed errors at intermediate stages of calculations, and therefore the final results must be considered highly doubtful.
Fortunately, this difficulty can be largely eliminated by good programming. As we have seen, in a conventional desktop adding machine there is also a very large possibility of recalculation errors. In this case, only large errors are detected immediately, and in order to prevent the accumulation of small errors, thorough checks are required at all stages. These checks form an important part of the entire sequence of calculations. But the same checks are an integral part of the program of an electronic computer. Due to its high speed, an electronic computer allows much more arithmetic checks than a desktop calculating machine. Consequently, with a well-designed program, an electronic computer provides not less, but much greater reliability of the results.
Above we talked about errors that appear due to insufficient control over the operations performed by the computer; but errors due to damage to the electronic circuit are also possible. To detect such errors, it is possible, for example, to provide for an automatic shutdown of the computer when errors occur, which are detected by the so-called parity check. In most machines, numbers are stored in binary notation as a sequence of zeros and ones. You can assign an additional digit equal to zero or one, depending on whether the sum of the ones in each stored number is even or odd. At certain points in time, for example when reading a number from a memory device, the assigned figure can be checked against the number itself. Such a verification scheme cannot, of course, be considered absolutely reliable, since compensatory errors may occur; but it is still very useful in drawing attention to errors caused by malfunctions in the electronic circuit.
These are some of the basic ideas associated with the use of electronic computers. The widespread use of computing technology has radically affected our computing capabilities, the scale of data processing, and, as a result, the general direction of research work and the choice of methods for its implementation. We will return to this aspect in Sect. 5.5 and 5.6, but for now let's take a closer look at some of the main problems for which computers are useful, and methods that allow researchers to take advantage of this new technology.
A recent book by Hollingdale and Toutill is an excellent introduction to computational methods.
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1. Introduction. The role and importance of VT in modern society. Areas of application of personal computers. There are many definitions of the scientific discipline "informatics". One of them is: Informatics is the science of methods of representation, accumulation, transmission and processing of information using a computer. This is the science of information activity, information processes. The existence of the science of "Informatics" is impossible without the study of the computer, since this science is associated with the time of its occurrence. Informatics is a scientific discipline with the widest range of applications. Its main directions are: development of computer systems and software; information theory, which studies the processes associated with the transmission, reception, transformation and storage of information; artificial intelligence methods that allow you to create programs for solving problems that require certain intellectual efforts when performed by a person (logical inference, learning, speech understanding, visual perception, games, etc.); system analysis, which consists in analyzing the purpose of the system being designed and in establishing the requirements that it must meet; methods of computer graphics, animation, multimedia tools; means of telecommunications, including global computer networks; a variety of applications covering manufacturing, science, education, medicine, trade, agriculture and all other activities. The term informatics denotes a set of disciplines that study the properties of information, as well as ways of representing, accumulating, processing and transmitting information using technical means. The theoretical basis of computer science is formed by a group of fundamental sciences: information theory, theory of algorithms, mathematical logic, theory of formal languages and grammars, combinatorial analysis, etc. Computer science includes the following sections: computer architecture, operating systems, database theory, programming technology and others. The modern era is characterized as the era of global information technologies: Previously accumulated information is gradually converted into digital form and stored in the global information networks. New information is produced in digital form by means of a computer. There are information networks covering workplaces and home computers. The field of study of informatics includes information systems designed to assist specialists, managers, decision-making and artificial intelligence systems. To use new information technologies it is necessary: 1. introduction of computers, office equipment; 2. participation of users in the information process; 3. accessible interface; 4. using application software packages; 5. access to databases using networks; 6. use of telecommunications. In computer technology, there is a periodization of the development of electronic computers. Computers are referred to one or another generation depending on the type of the main elements used in it or on the technology of their manufacture. It is clear that the boundaries of generations in the sense of time are very blurred, since computers of various types were actually produced at the same time; for an individual machine, the question of whether it belongs to one or another generation is solved quite simply.
2 In 1833, the English scientist Charles Babbage, who compiled tables for navigation, developed a project for an “analytical engine”. According to his plan, this machine was to become a giant computer-controlled adding machine. Babbage's machine also provided for arithmetic and memory devices. His machine became the prototype of future computers. But far from perfect nodes were used in it, for example, gears were used in it to memorize the digits of a decimal number. Babbage failed to carry out his project due to the insufficient development of technology, and the "analytical engine" was forgotten for a while. After 100 years, Babbage's machine attracted the attention of engineers. In the late 30s of the 20th century, a German engineer developed the first binary digital machine Z1. It made extensive use of electromechanical relays, that is, mechanical switches actuated by electric current. In 1941, Zuse created the Z3 machine, completely controlled by the program. In 1944, the American Howard Aiken, at one of the enterprises of IBM, built the Mark-1 machine, which was powerful for those times. In this machine, mechanical elements - counting wheels - were used to represent numbers, and electromechanical relays were used for control. Generations of computers It is convenient to describe the history of the development of computers using the concept of generations of computers. Each generation of computers is characterized by design features and capabilities. The division of computers into generations is conditional, since machines of different levels were produced at the same time. The first generation A sharp leap in the development of computer technology took place in the 40s, after the Second World War, and it was associated with the emergence of qualitatively new electronic devices - electronic vacuum tubes, which worked much faster than circuits based on an electromechanical relay, and relay machines quickly superseded by more productive and reliable electronic computers (computers). The use of computers has significantly expanded the range of tasks to be solved. Tasks that were simply not set before became available: calculations of engineering structures, calculations of planetary motion, ballistic calculations, etc. The first computer was built in in the USA it was called ENIAC. This machine contained about 18,000 vacuum tubes, many electromechanical relays, and about 2,000 tubes failed every month. The ENIAC machine, as well as other early computers, had a serious drawback - the executable program was not stored in the machine's memory, but was typed in a complex way with the help of external jumpers. In 1945, the famous mathematician and theoretical physicist von Neumann formulated the general principles of operation of universal computing devices. According to von Neumann, the computer was to be controlled by a program with sequential execution of commands, and the program itself was to be stored in the machine's memory. The first computer with a program stored in memory was built in England in 1949. In 1951, a computer was created in the USSR under the guidance of SA Lebedev, the largest designer of computer technology. Computers were constantly improved, thanks to which, by the mid-50s, their speed could be increased from several hundred to several tens of thousands of operations per second. However, the vacuum tube remained the most reliable element of the computer. The use of lamps began to slow down the further progress of computer technology. Subsequently, semiconductor devices came to replace the lamps, thus completing the first stage in the development of computers. Computing machines of this stage are usually called computers of the first generation. Indeed, the first generation of computers were located in large computer rooms, consumed a lot of electricity and required cooling with powerful fans. Programs for these computers had to be compiled in machine codes, and only specialists who knew the details of the computer could do this.
3 Second generation Computer developers have always followed the progress in electronic technology. When electronic tubes were replaced by semiconductor devices in the mid-1950s, the transfer of computers to semiconductors began. Semiconductor devices (transistors, diodes) were, firstly, much more compact than their lamp predecessors. Secondly, they had a significantly longer service life. Thirdly, the energy consumption of computers based on semiconductors was significantly lower. With the introduction of digital elements on semiconductor devices, the creation of second-generation computers began. Thanks to the use of a more advanced element base, relatively small computers began to be created, and there was a natural division of computers into large, medium and small. In the USSR, a series of small computers "Rozdan", "Nairi" were developed and widely used. Unique in its architecture was the machine "Mir", developed in 1965 at the Institute of Cybernetics of the Academy of Sciences of the Ukrainian SSR. It was intended for engineering calculations that were performed on a computer by the user himself without the help of an operator. Medium computers included domestic machines of the Ural, M - 20 and Minsk series. But the record among domestic machines of this generation and one of the best in the world was BESM - 6 ("large electronic calculating machine", 6th model), which was created by the team of Academician S. A. Lebedev. The performance of BESM-6 was two to three orders of magnitude higher than that of small and medium-sized computers, and amounted to more than 1 million operations per second. Abroad, the most common cars of the second generation were Eliot (England), Siemens (Germany). The third generation The next change of computer generations took place at the end of the 60s when semiconductor devices in computer devices were replaced by integrated circuits. An integrated circuit (microcircuit) is a small plate of a silicon crystal, on which hundreds and thousands of elements are placed: diodes, transistors, capacitors, resistors, etc. The use of integrated circuits has made it possible to increase the number of electronic elements in a computer without increasing their actual size. The speed of the computer has increased to 10 million operations per second. In addition, it became possible for ordinary users to compose computer programs, and not only for specialists - electronics engineers. In the third generation, large series of computers appeared, differing in their performance and purpose. This is a family of large and medium IBM360/370 machines developed in the USA. In the Soviet Union and in the CMEA countries, similar series of machines were created: ES EVM (Unified Computer System, large and medium machines), SM EVM (Small Computer System) and "Electronics" (micro-computer system). Fourth generation In the process of improving microcircuits, their reliability and the density of the elements placed in them increased. This led to the emergence of large integrated circuits (LSI), in which there were several tens of thousands of elements per square centimeter. On the basis of LSI, computers of the next - the fourth generation were developed. Thanks to the LSI on one tiny silicon crystal, it became possible to place such a large electronic circuit as a computer processor. Single-chip processors subsequently became known as microprocessors. The first microprocessor was created by Intel (USA) in 1971. It was a 4-bit microprocessor Intel 4004, which contained 2250 transistors and performed 60 operations per second. Microprocessors marked the beginning of minicomputers, and then personal computers, that is, computers oriented to one user. The era of personal computers (PC) has begun. In addition to personal computers, there are other, much more powerful computer systems. The influence of personal computers on people's understanding of computer technology turned out to be so great that the term "computer" gradually disappeared from everyday life, and the word "computer" firmly took its place.
4 Fifth generation Beginning in the mid-1990s, super-scale LSIs began to be used in high-performance computers, which contained hundreds of thousands of elements per square centimeter. Many experts began to talk about computers of the fifth generation. A characteristic feature of fifth generation computers should be the use of artificial intelligence and natural languages of communication. It is assumed that fifth generation computers will be easily manageable. The user will be able to give the machine a command by voice. The transition to fifth-generation computers meant a transition to new architectures focused on the creation of artificial intelligence. It was believed that the architecture of fifth generation computers would contain two main blocks. One of them is the computer itself, in which communication with the user is carried out by a unit called the “intelligent interface”. The task of the interface is to understand the text written in natural language or speech, and to translate the condition of the task stated in this way into a working program. Basic requirements for computers of the 5th generation: creation of a developed human-machine interface (recognition of speech, images); development of logic programming to create knowledge bases and artificial intelligence systems; creation of new technologies in the production of computer technology; creation of new architectures of computers and computing systems. Classification of WTs There are many different types of computers, including: supercomputers, mainframes, servers, desktops, workstations, laptops, ultraportables. Supercomputers Nowadays, supercomputers are called computers with huge computing power. Supercomputers are different from servers, which are necessary for online processing of requests. They are also different from mainframes, which also have high performance, but serve to work with many users at the same time. Supercomputers can also be used to work with a single program. Which requires powerful resources. This is weather modeling, calculation of the manufacturing process, nuclear tests. The most "advanced" processors in Russia today are the MCST R1000 models (four cores, frequency 1 GHz) and the hybrid six-core Elbrus-2C +. Both microcircuits are manufactured using 90-nm technology. By the end of 2012, the company is expected to release a quad-core Elbrus-4S processor manufactured using 65-nm technology, and in 2015, MCST plans to complete the development of an eight-core processor under a government contract with the Ministry of Industry and Trade. Now the main market for processors is the defense sector. One of the largest projects where they are used is air defense systems. Servers
5 Servers are high performance computers used by businesses and other organizations. Servers serve many end users or clients. Desktop Computers There are different types of desktop computers with different capabilities. Desktop computers support a variety of connection types, video options, and a wide variety of peripherals. Workstations Workstations are high power commercial computers. They are designed for specialized professional applications, such as running design programs such as CAD (computer-aided design). Workstations are used to create 3D graphics, animation, and virtual reality simulations. In addition, they can be used as control stations for telecommunications or medical equipment. Like servers, workstations typically come with multiple CPUs, plenty of RAM, and a few fast, high-capacity drives. Typically, workstations have very powerful graphics capabilities and a large monitor, or multiple monitors. Portable Devices In addition to desktop computers of various types, there are many more portable electronic devices. They vary in size, power, and graphics capabilities. This category includes: portable PC or laptop; tablet PC; pocket PC; personal digital secretary. Personal computers The appearance of the PC was prepared by the entire previous history of the development of computers. In the beginning, computers occupied huge halls, consumed a lot of energy and created a lot of noise. Then the computers became smaller and began to work more efficiently, but still required separate rooms for themselves. The most powerful computers were located in separate complexes, which were called computer centers (CC). In those not very distant times (70s), few people imagined a compact computer that could fit on a desktop. Engineers and scientists could only dream of such a machine, and it would be difficult for ordinary people to explain why such a computer is needed at all. The first sign was a computer designed in 1971. Outwardly, it looked more like a car radio with indicator lights and switches than a familiar personal computer. From 1971 to 1974, different companies created different models of PCs. But due to the limited capabilities of these computers, there was little interest in them. Users and manufacturers really became interested in personal computers in 1974, when the American company MITS developed the Altair computer based on the Intel 8080 microprocessor. This personal computer was much more convenient than its predecessors and had more features. A much more advanced model of the personal computer was developed in 1976 by two young Americans, Steve Wozniak and Steve Jobs. They called their computer Apple and quickly expanded its production and sale. Due to the low price (about $500), they sold about 100 computers in the first year. The following year, they released the Apple II, which had a motherboard, display, keyboard, and looked like a TV. The number of customers on the PC began to number in the hundreds and thousands. Personal computers improved rapidly, in 1978 a flexible magnetic disk with a diameter of 5.25 inches (1 inch \u003d 2.45 cm) was designed for them, designed to store information. In 1979, MOTOROLA created the motorola 68000 microprocessor, which surpassed its competitors in terms of speed, performance, and graphics program capabilities. AT
On 6 1980, a hard magnetic disk appeared in personal computers, however, it contained only 5 MB of data. The first PCs were 8-bit and looked more like an expensive toy than a serious computer. This continued until the computer giant appeared in the industry of individual computers - IBM, which specialized in the manufacture of large computers. In 1982, IBM released a very successful bit computer. It was based on the Intel 8088 microprocessor, ran at 4.77 MHz, and used the MS DOS operating system. This computer model was called the IBM PC. Further, the development of the PC took place at a very high pace: every year IBM created a new model. In 1983, the PC XT model appeared, and in a more advanced and productive PC AT computer. They quickly conquered the PC market and became a kind of standard that competing firms tried to imitate. IBM did not create its personal computer from scratch, but using components from other manufacturers (primarily the Intel microprocessor). However, she did not make a secret of how the nodes of the computer should connect and interact with each other. As a result, other firms could be involved in the creation and improvement of the computer - the architecture of IBM PC computers turned out to be "open". IBM computers have numerous "clones", that is, various families of computers similar to the IBM PC. In the future, computers supporting the IBM PC standard were simply called "personal computers". Over time, PCs have lived up to their name, as for many people they have become an indispensable part of leisure, a tool for business and research. In addition to IBM - compatible PCs, there is another family of personal computers called Macintosh. These computers trace their lineage from the already mentioned Apple model, they were produced by Apple Computer. The architecture of Macintosh computers, unlike the IBM PC, was not open. Therefore, despite their more advanced graphics capabilities than the IBM PC, Macs were unable to conquer such a vast market. The number of "Poppies" is ten times less than the number of IBM PC - compatible computers. The main trend in the development of computer technology at present is the further expansion of the scope of computers and, as a result, the transition from individual machines to their systems - computer systems and complexes of various configurations with a wide range of functionality and characteristics. The most promising - computer networks - are focused not so much on the computational processing of information, but on communication information services: e-mail, teleconferencing systems and information and reference systems. In recent years, heavy-duty computers - supercomputers and miniature and subminiature PCs - have had a significant and stable priority in the development and creation of computers proper. As already mentioned, search work is underway to create computers of the 6th generation based on a distributed neural architecture - neurocomputers. In particular, already existing specialized network MPs - transputers - network microprocessors with built-in communication facilities, can be used in neurocomputers. The widespread introduction of multimedia, primarily audio and video input and output of information, will allow you to communicate with a computer in natural language. The new technical capabilities of computer technology were supposed to expand the range of tasks to be solved and make it possible to move on to the tasks of creating artificial intelligence. As one of the components necessary for the creation of artificial intelligence are knowledge bases (databases) in various areas of science and technology. The creation and use of databases requires a high-speed computing system and a large amount of memory. Mainframe computers are capable of high-speed calculations, but are not suitable for high-speed comparison and sorting operations of large amounts of records, usually stored on magnetic disks. To create programs that provide filling, updating databases
7 data and work with them, special object-oriented and logical programming languages have been created that provide the greatest opportunities compared to conventional procedural languages. The structure of these languages requires a transition from the traditional von Neumann computer architecture to architectures that take into account the requirements of the tasks of creating artificial intelligence. Test questions 1. Expand the basic concepts of computer science. 2. On what principles are new information technologies based? 3. What device is called a computer? 4. List the signs by which computers are classified. 5. What is the classification of computers by purpose?
8 Section 1. General composition and structure of PCs and computing systems. Principles of building a computer and VS. Trunk-modular principle, general functional scheme Modern computers were preceded by a half-century period, which is divided into generations of computers. If the list of functional blocks itself has not changed for more than half a century, then the methods of their connection and interaction have undergone some evolutionary development. Computer architecture - a description of the device and principles of operation of a computer, its technical device. The basic principles of building a universal computer were outlined by John von Neumann in 1946, according to which a universal computer was built in 1949. The diagram shows the functional structure of a 1-2 generation computer. Functional scheme according to the von Neumann principle Computer devices: 1. ALU arithmetic logic unit for performing arithmetic and logical operations. 2. CU control device for executing programs. 3. RAM for storing programs and commands. 4. VU external input-output devices. The operation of the computer is as follows: with the help of the VU, a program is entered into the RAM; The CU reads the contents of the memory cell and executes the command, then the contents of the next one are read. The order of execution can be changed forcibly using jump commands. Two blocks ALU and CU are combined into a common processor. From the above diagram, it is clearly seen that the processor is the center of such a design. Firstly, it controls all devices, and secondly, all information flows pass through it. The described system, by definition, has a fundamental drawback: the processor is excessively overloaded. By fully regulating the exchange between all devices, it is often forced to passively wait for the end of input from slow (usually containing mechanical parts) devices, which significantly reduces the efficiency of the entire system as a whole. Computers with a channel organization The emerging contradiction between the ever-increasing performance of the processor and the relatively low speed of exchange with external devices became clearly visible already during the heyday of second-generation computing technology. Therefore, when designing the next, third, generation, engineers began to take special measures to "unload" the processor and free it from detailed I/O control. Computers of the 3rd generation had a functional diagram with a channel organization. In addition to the already familiar set of devices (central processor, memory, input-output devices), computers with a channel organization include devices called channels. A channel is a specialized processor that performs all the work of controlling the controllers of external devices and exchanging data between the main memory and external devices. Devices are grouped by characteristic speed and connected to the corresponding channels. "Fast" devices (for example, magnetic disk drives) are connected to selector channels. Such a device receives
9 selector channel in exclusive use for the entire duration of the data exchange operation. "Slow" devices are connected to multiplex channels. The multiplex channel is divided (multiplexed) between several devices, while simultaneous data exchange with several devices is possible. Both the CPU and one of the channels can access the RAM. To control the order of access, there is a RAM controller. It determines the priority access discipline when multiple devices access memory at the same time. The CPU has the lowest priority. Among channels, slow channels have higher priority. Thus, priority is inversely proportional to the frequency with which devices access memory. Due to the significant complication of computer organization, the input-output architecture is simplified. Data exchange operations become simpler. The channel, in fact, is a specialized "smart" DMA controller. The channel can inform the processor about its state using interrupts. All controllers of external devices are connected to "their" channels using a standard interface. The freedom to connect external devices is maintained thanks to the standard interface protocol, while it becomes possible to group devices according to their characteristics. In a computer with a channel organization, the processor is almost completely freed from the routine work of organizing input-output. The control of controllers of external devices and data exchange takes over the channel. The presence of several data transmission paths removes the difficulties associated with blocking a single data transmission path (system bus), which increases the exchange rate. All this makes it possible to exchange data with external devices in parallel with the main computational work of the central processor. As a result, the overall performance of the system increases significantly. The increased cost of the scheme pays off. One of the first machines with channels was the second-generation computer IBM-704. A striking example of computers with channels are machines of the IBM-360/370 family. The appearance of these computers revolutionized computer technology, and for many years they became a role model for the creators of computers. Although these machines are now a thing of the past, they left a rich legacy in the form of interesting architectural solutions, software and algorithmic developments. Currently, circuits with specialized input-output processors are often found in computers of various types. Computers with a bus organization The transition to the fourth generation of computers was not only accompanied by a multiple increase in the density of assembly in microcircuits, but also by a change in the general strategy for the use of computer technology. The bulky computers for collective use were replaced by personal computers, designed primarily for the individual work of individual users. At the same time, the architecture continued its development and improvement in the direction of freeing the processor from the leadership
10 I/O processes. As a result, a modern PC has acquired the structure shown in the diagram. The main feature of such a scheme is the presence of a dedicated bus (highway) for transferring information between the functional units of the computer. It consists of three parts: the address bus, which determines exactly where information is sent on the bus; data bus through which information is transmitted; a control bus that determines the features of the exchange and synchronizes it. All computer devices are connected to the bus, starting from the processor and ending with input and output devices. An essential feature of the PC architecture is the presence of specialized input / output processors, which are called controllers. Their role is to support the exchange of information for a given device, as well as to coordinate with the standard bus of various external devices from different manufacturers. To communicate with the memory, it is necessary to transfer the addresses of the necessary cells from the CPU and read the corresponding data from them, and to ensure communication between the nodes, a control bus is introduced. Information is exchanged between blocks via SD, SHA is designed to transfer addresses of memory cells or input-output ports that are accessed, SHU for transmission of control signals. These buses are called the system bus or backbone. Functional diagram of a computer with a bus organization Consider the operation of a computer. When turned on, read-only memory (ROM) transmits raw data. The CPU is brought online and connects all nodes to the buses. Programs permanently stored in ROM chips are referred to as hardware. Random Access Memory (RAM) reserves space for programs, instructions, and data. During operation, the processor performs the following operations: determines the addresses of the required cells; reads data or instructions from them; follow instructions (count); sends data to specific memory cells; specifies the display port address; using the controller sends data to the display. In this scheme, all devices are symmetrically connected to one channel of the common bus. This makes it possible to connect new devices. Thanks to the bus architecture, it is easy to make any changes required by a particular user in the computer configuration. The described scheme also has a "bottleneck" - it requires a high bus bandwidth. To overcome this difficulty, modern designs use multiple buses, each of which connects the processor to a specific device or group of devices. The architecture of modern computers The operation of modern computers is determined by the chipset - a set of control chips installed on the motherboard. Previously, chipsets were used that consisted of many controllers, and the first chipsets appeared in the mid-80s of the last century. The transition to chipsets has reduced the cost of motherboards and increased the mutual compatibility of components, which facilitated the task of designing motherboards. The common architecture of modern chipsets is based on
11 using two chips that form the basis, the so-called north bridge and south bridge. The northbridge chip provides work with the fastest PC subsystems. Contains a system bus controller, a memory controller, a graphics bus controller, a southbridge communication bus controller that provides support for slower system components and peripherals. The south bridge chip usually includes: a two-channel IDE (SATA) controller, a USB controller, and an integrated audio system (audio codec). The southbridge is responsible for working with slower devices and provides data transfer from the hard drive, optical drive, printer, scanner, as well as to them. These devices transmit information via wires to the southbridge, which forwards it to the northbridge. The northbridge sends information to RAM, after which it can go to the processor or video card for processing. The chipset is a kind of intermediary in the communication of the processor with the rest of the devices in the computer system. The tasks of the chipset include managing the operation of computer components and ensuring the transfer of data between them. At the same time, each chipset serves only the architecture of the processor for which it was designed. Since 2005, chipsets from different manufacturers have focused on the use of multi-core microprocessors. The names of the bridges were given by analogy with a geographical map, on which the North Pole is located at the top, and the South Pole at the bottom. Test questions 1. Expand the concept of computer architecture. 2. Features of the functional scheme according to von Neumann. 3. Features of a functional diagram with a channel organization. 4. Features of the functional scheme with a channel organization. 5. Features of the scheme of modern computers.
12 Section 1. General composition and structure of PCs and computing systems. The internal architecture of a computer: processor, memory. Peripherals. Assigning computer devices. Most computers need three elements to work together to function properly. 1. Hardware - the internal and external physical components that make up a computer. 2. Operating system - a set of computer programs that control computer hardware. 3. Application software (applications) - programs that are downloaded to perform specific tasks using the capabilities of a computer. A modern personal computer consists of the following components 1. The motherboard is a large printed circuit board to which all the electronics and circuits that make up the computer system are connected. This board has connectors that connect the main components of the system, such as the CPU and RAM. The motherboard provides communication between various connectors and system components. In addition, the motherboard has slots for a network card, a video card, and a sound card. Many motherboards have these components built into them. The difference is in the update method. When using a motherboard with connectors, system components can be easily removed and replaced with more modern ones.
13 The selected motherboard must: support the type and speed of the selected CPU; support the type and amount of RAM required to run applications; have enough slots for all required interface boards; have a sufficient number of interfaces of the required type. This board, with the help of which the remaining components (parts) of the computer are combined and function together. 1. PCI slot - used to connect various boards, such as modem, sound card. 2. Video card input. 3. Slot for the processor. 4. Input for powering the processor from the power supply 5. Connector for connecting a hard drive or drive (CD-DVD) with an IDE ATA interface 6. Connectors for connecting hard drives or drives (CD-DVD) with a SATA interface 7. Slots for RAM 8. Input for connection (drive device for reading floppy disks). 9. Connector for connecting power to the motherboard from the power supply, in this image 24 pin (number of pins) or 20 pin.
14 Rear panel 1. PS/2 - Mouse input (Always green). 2. PS/2 - Keyboard input (always Purple). 3. Digital input. 4. Digital output. 5. USB universal ports for connecting various devices. 6. Input for a network cable (local network, dedicated Internet). 7. Outputs for connecting an audio system (speakers.) 2. Processor. The processor performs all calculations, operations and gives commands to other components. The frequency of the processor is measured in megahertz, the higher the frequency, the more operations per second it can perform. The processor also has its own small cache memory, in which it stores the most frequently performed operations, which increases its speed. Processor cache is measured in megabytes, and its capacity is typically around 8 megabytes to 32 at the moment, the larger the cache, the more expensive the processor. Modern processors have several cores, it turns out, as it were, several processors in one. Which makes it much more productive and increases the speed of its calculations. Most modern processors are implemented as a single semiconductor chip containing millions, and more recently even billions of transistors. The microprocessor includes: control unit (CU) - generates and delivers to all machine blocks at the right time certain control signals (control pulses) due to the specifics of the operation being performed and the results of previous operations; generates the addresses of the memory cells used by the operation being performed, and transfers these addresses to the corresponding blocks of the computer, the control device receives the reference pulse sequence from the clock pulse generator; arithmetic logic unit (ALU) - designed to perform all arithmetic and logical operations on numerical and symbolic information (in some PC models, an additional mathematical coprocessor is connected to the ALU to speed up the execution of operations); microprocessor memory (MPM) - serves for short-term storage, recording and issuance of information directly used in calculations in the next cycles of the machine. MPP is built on registers and is used to ensure high machine performance, because the main memory (OP) does not always provide the speed of writing, searching and reading information necessary for the efficient operation of a high-speed microprocessor. Registers are high-speed memory cells of various lengths (unlike OP cells, which have a standard length of 1 byte and lower speed); microprocessor interface system - implements interfacing and communication with other PC devices; includes an internal MP interface, buffer storage registers and control circuits for input-output ports (IOP) and the system bus.
15 3. RAM in a computer plays the role of a temporary buffer for storing information, that is, when you start an application, it is partially loaded into RAM, therefore, the more such memory you have, the more you can open and work in several programs at the same time, for example, playing a computer game and listening to music at the same time. A large amount of RAM is required in modern games. RAM has two main characteristics - its volume and the frequency at which it operates. 4. The video card is designed to display the image on the monitor, it is responsible for graphics processing. If a weak video card is installed, then it cannot cope with graphics processing. Modern video cards have their own built-in processor (core), the power of which is also calculated, like that of the central processor in megahertz. Its task is to remove the load of graphics processing from the central processor and take over this task, that is, the higher the frequency, megahertz at the core of the video card, the faster it processes graphics, therefore, games run faster. The video card also has memory, video memory, with the help of which it stores textures, processed parts of graphics, video memory is again calculated in megabytes, gigabytes. 5. Adapter cards expand the capabilities of a computer system. They are inserted into the motherboard connectors and become part of the system. Many motherboards have built-in adapter card functionality, eliminating the need for additional components. Embedded boards support basic functionality, but specialized adapter boards often improve system performance. The most common are the following boards: video boards; sound cards; network interface cards; modems; interface boards; controller boards. 6. The power supply supplies electricity to all components of the computer, and allows it to work. A cable from the mains goes into it, and then they distribute the voltage throughout
16 computer. The power of the power supply is calculated in watts, the more powerful your computer, the more powerful the power supply it requires, modern video cards are very demanding on power supplies, which sometimes need a power supply up to a kilowatt. Power cables run from the power supply to the motherboard, hard drives, coolers, and drives. High-quality power supplies are more resistant to voltage fluctuations in the network, which prevents the failure of the unit itself and all computer components. 7. Hard drive. The hard drive stores programs, games, documents. Like any storage, it has a maximum capacity, which is measured in gigabytes. The larger the hard drive, the more information you can store on it. The hard drive is a mechanical device. It spins several layers of disks, on which information is written and read using a magnetic head. The hard disk also has its own temporary high-speed buffer, cache, it is arranged in the form of a small chip, with the help of which the hard disk reduces the number of physical accesses directly to the disks, thereby increasing the speed and service life. 8. Peripherals. A peripheral is a device that connects to a computer and expands its capabilities. These devices are optional in nature and are not required for basic functionality. They only provide some additional functionality. Peripherals are connected from the outside of the computer, using special cables or wirelessly. They fall into one of four categories: input, output, storage, or network devices. Examples of peripheral devices are: input devices trackball, joystick, scanner, digital camera, encoder, barcode reader, microphone; output devices printer, plotter, speakers, headphones; storage devices optional hard drive, external CD/DVD drives, flash drives; network devices - external modems, external network adapters. 9. Permanent memory. ROM (English ROM, read-only memory) is used to store immutable (permanent) program and reference information. In the first personal computers, the BIOS code was written to a ROM chip that was created at the factory. Later, rewritable chips began to be used to store the BIOS code.
17 EEPROM chip. Main parameters: Memory capacity - 16 Mbit, Sample time - 65 ns. General description: Supply voltage range: 3.0-3.6V; Technological process 0.25 microns, Ability to erase any combination of sectors and all memory; Guaranteed number of erasing cycles; Data retention time 13 years at 125 C; Temperature range: C. Location of the motherboard BIOS. In most cases, flash-memory is installed on the motherboard panel, which allows you to replace the chip if necessary, but in some cases it is soldered directly on the motherboard. Flash memory chips for BIOS storage vary in capacity, with older computers using chips of 1-2 Mbps (KB) and modern systems 4-8 Mbps or more (512 KB-1 MB or more). The BIOS uses configuration settings that are stored in a special CMOS memory. It got its name from the chip manufacturing technology, where a complementary metal oxide semiconductor was used. The CMOS memory is powered by a special battery on the motherboard, which is also used to power the real time clock. The life of such a battery is usually 10 years. As a rule, during this time, the computer (in particular, the motherboard) becomes morally obsolete, and the need to replace the power element becomes meaningless. With some technologies for the production of CMOS chips, the battery is built right into the chip. In this case, when the battery is discharged, it must be replaced entirely. Computer startup procedure Programs written to ROM chips are available to the computer immediately after being turned on. Programs in ROM are divided into: machine startup program, basic input-output system (BIOS). The role of the BIOS is twofold: on the one hand, it is an integral element of the hardware, and on the other hand, it is an important module of any operating system. These programs are executed every time you turn it on. The launch consists of several phases: checking the machine's performance, initializing programmable microcircuits, peripheral devices, checking for the presence of additional equipment, loading the operating system. Test programs are short and fast. The last operation is the loading of the operating system, performed by the program loader. After the OS is loaded from the disk, control is transferred to it. The BIOS is part of the ROM is actively used during the entire time the computer is running to control devices (contains their drivers) display, keyboard, drive, handles interrupts, provides energy saving, automatic configuration. Interrupts are signals from the outside world that inform the processor about the occurrence of an event (pressing a key, serving a floppy disk). The BIOS uses software interrupts to call and execute special service programs.
18 During startup, messages about the operation of check programs appear on the screen, a shell program or operating system prompt appears, further work takes place under the control of the OS. Computer diagnostics 1. The computer does not turn on - does not respond to pressing the power button, the computer turns on, but nothing is displayed on the monitor - coolers work in the system unit. Option number one - when turned on, the speaker emits a single sound (beep), that is, it reports that everything is in order in this case, the main probability is that the video card has burned out. Option number two, the speaker is silent (does not beep), from this we conclude that either the motherboard or the power supply has broken, this also applies to the case when the computer does not respond in any way to pressing the power button. Speaker is a small speaker in the system unit, connected to the motherboard, which informs the user when starting the computer about the status of the components and the general operation of your computer. Deciphering (basic) sound combinations Speaker a 1 short beep everything works properly. There are no signals - there are problems with the power supply, it may not be connected to the motherboard, there is also a small percentage of the possibility that the motherboard itself is faulty. Continuous signal - a problem with the power supply. 2 beeps, minor errors. 1 long recurring RAM issue. 2. Every time you start the computer, you have to press the F1 key, and until this is done, the computer does not start loading. If every time you turn on your computer, your system time and date are reset, then the reason for this is a dead battery on the motherboard. In this case, you need to replace the battery on the system board and then go in and out with saving the BIOS settings. Control questions 1. What is the simplest PC configuration. 2. What is included in the system unit. 3. What is the motherboard? 4. Purpose of the microprocessor. 5. List the types of memory. 6. What does the term "periphery" mean?
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Back in 1984 in the United States during the presidential election, one of the senators, having learned that in order to implement the SDI project (strategic defense initiative, better known as the concept of "star wars"), it is necessary to use high-speed computers (performing information processing instantly) for decision-making, completely rightly concluded that this circumstance actually excludes the intervention of the US President in this process. Therefore, he proposed to elect the computer of the US military control system to the post of head of state. This amusing episode of world history eloquently proves that computer technology (CT) has become an integral part of this very history, has firmly established itself in the present and, for sure, will not miss its own in the future.
The hackneyed phrase that “computer technology and information technology have firmly entered our lives” passes from one textbook to another, is found in almost all publications devoted to computers, lectures and seminars, etc. begin with it. Therefore, we will not go away from this, especially since we used it in the very first sentence, the first paragraph.
However, we will not give numerous examples of the use of VT in everyday life as trading terminals, personal computers (this list can be continued indefinitely). Any more or less literate person begins to use the fruits of informatization almost from birth and with pleasure (or disgust, for which many of us have good reason) will continue this list.
In the 80s. 20th century Time magazine recognized the computer as the person of the year. Surely many of you, reading this phrase, smiled. It's quite funny to hear that the "piece of iron" that is on your desktop has such a high rank, but is this not true proof that the computer is not just an important part of our life, we simply cannot imagine ourselves without it. The computer is part of us, try to refute this statement or agree with it, it doesn't matter anymore. One thing is clear, it is foolish to refuse a computer, it has shouldered too many things on its “shoulders”.
Strictly speaking, electronic computer (computer) or a computer is a complex of hardware and software tools designed for automatic processing of information necessary to solve the problem that was set byuser . We will consider the hardware part of computer technology and software later in topic 3, but now I would like to dwell on the user in more detail. The user is always a human. Very remarkable is the fact that the concept of "user" has constantly evolved. At the dawn of the advent of computer technology, computers were used, as a rule, by scientists working for the military departments of their countries (machine projectUNIVAC, USA 1945). Then, as the unit of time of work on computers became cheaper, scientists and engineers of civilian specialties gained access to their computing power. With the development of microelectronics and informatics, and they really moved at an enormous speed, mass-produced computers began to appear, whose size decreased as much as their performance increased by orders of magnitude. Now, personal computers are available to almost everyone. They occupy an area that is equal to several tens of square centimeters, instead of several floors of a huge building just some 60 years ago. The user has becomesole owner personal COMPUTER.
NOTE
The very word a computer , as it is not difficult to guess, comes from the English words " to compute", « computer", which are translated as "calculate", "computer". An interesting fact is that originally in English this word meant a person who performs arithmetic calculations with or without the involvement of mechanical devices. And only many years later, the meaning of this word was transferred to the machines themselves. First definition of a word a computer was given in 1897 in the Oxford English Dictionary. Its compilers then understood the computer as a mechanical computing device.
In all the diversity and heterogeneity of user armies, a special role belongs to three categories of people - customers of work to be performed on a computer, software designers and programmers. Therefore, very often, the word "user" means exactly the "end user" of the product that the "customer" needs, invented by the "designer" and implemented by the "programmer". Recently, another category of computer users has become isolated - the “knowledge engineer” (cognitologist), who is a key link in the process of creating expert systems for various purposes. The problems of developing knowledge bases and expert systems are beyond the scope of this book, but are discussed in detail in.
As noted above, computers automatically process the information required to solve the problem. The information processing process is much more efficient when it is carried out within a certain system. Very capacious and precise definitioninformation system (InS) is given in the book, where an information system is understood as a system in which the subject and product of labor is information.
A feature of information systems is that they belong to the class of material systems, and their final product (information) is not material. Any material product is produced according to a certain technology, which combines the methods and means of its production. For example, one of the technologies for obtaining sulfur from hydrogen sulfide gases is based on the Claus method and uses a plant consisting of two thermal and two (rarely three) catalytic reactors. A technology that uses information transformation methods and computer technology to implement them, and receives information at the output, is calledinformation technology (IT). Modern IT provides the receipt, transformation and transmission of huge amounts of information over long distances for strictly defined periods of time in order to ensure timely solution of the problem. As areas of application of modern IT, the following can be indicated: computer-aided design systems (CAD /CAD); production enterprise management systems (UPP /ERP); control systems for technological processes and productions (APCS /SCADA); banking systems; publishing systems; digital cellular communication and the Internet, etc.
