Fundamentals of computer science and computer technology GDZ. Fundamentals of computer science and computer technology abstract. "fundamentals of computer science and computer technology"

EXERCISES
1. A skydiver jumped from an airplane flying at a speed of 180 km/h at an altitude of 1300 m and opened his parachute at an altitude of 600 m. Air resistance is proportional to the square of the speed. Create an algorithm that determines the time a parachutist falls until the parachute opens.
2. Under the conditions of exercise 1, the parachutist at an altitude of 1000 m is grouped and the drag coefficient decreases from 0.004 to 0.003. Create an algorithm that calculates the time a parachutist falls until the parachute opens.
3. Create an algorithm similar to the “falling” algorithm to calculate the oscillations of a load on a spring (acceleration is proportional to the magnitude of the deviation from the equilibrium position).
4. The ball was suspended from a spring from a school dynamometer, pulled down from the equilibrium position by 1 cm and released. The stiffness of the spring is such that at the moment the ball is released, its acceleration under the influence of gravity and the elastic force of the spring is equal to - 4 m/s2. Create an algorithm that determines how many seconds it will take for the ball to rise to its maximum height.
5. Create an algorithm that calculates the coordinates and speed of a ball released at a height h m above an infinite inclined plane inclined at an angle a to the horizontal, t seconds after the start of movement. The blows are elastic.
6. Solve exercise 5 if, with each bounce of the ball from the plane, the modulus of its speed decreases by n%.
7. A body moves along an inclined plane under the influence of gravity. The drag force is proportional to the speed of the body. Create an algorithm that calculates the length of the path traveled by a body during time t from the start of movement.
8. An elastic ball was placed on the top step of an endless staircase (width of steps 1, height h) and rolled it with speed v. Assuming the ball is a material point and the impacts are elastic, create an algorithm that determines the numbers of the first n steps on which the ball will hit.
§ 27. COMPUTER DESIGN AND PRODUCTION
27.1. COMPUTER DRAWING
What can a computer give to a designer and technologist in modern production? First of all, it can make working with drawings easier. With the help of a computer, a new drawing can be prepared several times faster than on a regular drawing board. If the drawing is already stored in a computer and small changes need to be made to it, then this can be done tens of times faster than with a drawing board. It is enough to indicate which parts of the old drawing need to be replaced and what needs to be placed in their place, and the computer will create a new drawing. The most frequently occurring fragments of drawings, individual blocks and nodes can be stored in computer memory and used when creating new drawings. The use of such a library of drawings makes it possible to increase the productivity of an engineer behind an “electronic drawing board.”
27D. COMPUTING EXPERIMENT
No new design should be used without testing. If a computer is used to create a design, then all information about the design is in the computer’s memory. In this case, tests can be carried out without manufacturing the structure, but by simulating its behavior on a computer. In this case, the constructor can calculate various characteristics(for example, weight, volume, coordinates of the center of gravity), observe the operation of the structure in different modes(including those that are impossible or dangerous to reproduce in practice). The design can be easily changed during these computer tests, choosing the best option, studying how the stresses will be distributed during the operation of the structure, etc. Such modeling dramatically reduces development time and improves its quality.
27.3. MACHINES WITH NUMERICAL PROGRAM CONTROL |CNC|
If the Draftsman replaces the paper with a sheet of metal, and the pen with a cutter, then we will receive commands like “lower with a cutter”, “move with a cutter (thing x. y)”, etc. Devices of this kind, working with real metal workpieces, are called machines with numerical control (CNC). Included in the machine
It may also include a control computer, into whose memory the work program is received via communication lines.
By changing the program in the computer memory, you can reconfigure the machine to produce a new type of part. This makes it possible to create flexible automated production (GAP), i.e. production, the reconfiguration of which to produce other products is carried out by changing information (programs) in the computer memory.
27.4. DESIGN AND PRODUCTION - A SINGLE CYCLE
Having calculated the required part on a computer and having machines with numerical control, you can combine design and production into a single cycle. In this case, the information obtained during design will be used directly for production without leaving the computer. This approach can significantly reduce the development and production time of new products. Having the required shape of the part in the computer memory, you can use the same computer to calculate how the machine cutter should move in order to produce this part. Knowing the trajectory of the cutter, you can calculate the processing speed, coolant supply, etc. The use of a computer allows you to manufacture complex parts accurately, with high accuracy and without human intervention. The supply of workpieces from the warehouse, their transfer from machine to machine and sending to the finished product warehouse can be carried out by computer-controlled robots, transport carts, etc.
27.5. THE SIMPLE EXAMPLE OF AN INFORMATION MODEL IN COMPUTER DESIGN
Suppose you need to represent a surface of a complex shape in a computer, for example, the hood of a car. One method, called the finite element method, is to break the surface of the hood into small pieces that can be roughly considered flat, such as triangles. To define such a surface made up of triangles in a computer, you can use the M20 information model:
int N | number of triangles (M20)
EXERCISES
1.,The M20 model is uneconomical: the same vertex can be included in several triangles and its coordinates will be stored multiple times. Modify the M20 model so that information is not duplicated.
2. Assuming that the thickness of the hood and the density of the metal are known, create an algorithm for calculating the weight of the hood within the framework of a) the M20 model; b) your solution to exercise 1.
3. Create an information model for representing volumetric parts and algorithms for finding a) weight; b) surface area of the part.
4. Come up with a way to set the temperature on the surface of the M20 model. Create algorithms that calculate: a) the maximum temperature of the model; b) average temperature of the model; c) the area of the surface zone where the temperature is above 100°.
§ 28. FROM INDUSTRIAL SOCIETY TO INFORMATION SOCIETY (CONCLUSION)
We have considered only some of the largest areas of application of computers. It is now hardly possible to list them all - the number of personal, home, gaming, built-in and other computers has already reached hundreds of millions. Computers are built into airplanes and cars, into watches, washing machines, food processors and even sports shoes. The use of computers has made it possible, for example, to create a satellite navigation system for cars (when a map of the surrounding area and the exact position of the car are displayed on the screen in front of the driver, no matter where he is). The use of computers opened the way to the “world library” - the opportunity, without leaving home, to obtain a copy of any book, article, description of a particular invention, etc. In developed countries, a person from his own home computer can order tickets for trains, planes, ships along a complex route with many transfers, reserve hotel rooms for the required dates, and even order theater tickets at transfer points. And this is just the beginning of the formation of global information networks!
But we don’t travel every day, but we buy something almost every day. And here a computer can help too.
28.1. ELECTRONIC STORE, BARCODE AND ELECTRONIC MONEY
Perhaps you have seen a rectangle of black and white stripes on some imported goods (photo insert). This is a unique barcode for the product. In modern stores, the cashier should neither enter the cost of the product nor even remember it (and this is impossible when in one store there are over 30 thousand items of different goods). It is enough to swipe the bar code past the cash register reader, and the computer itself will determine the price of the product, and at the end will display the cost of all purchases on the display board.
For each product, the store's computer remembers not only its current price (and the price may change depending on the demand for the product), but also its quantity. If the stocks of some goods are running out, then the computer itself (by information network) will send a request to the warehouse. The warehouse computer, having received such requests from different stores, will plan the optimal loading of transport, transportation routes - and by morning all the goods will be in place.
What about our buyer? After all, he needs to pay for the goods. Don't think that he will count the pieces of paper and count the change. For payments, electronic money is used - special plastic cards that store information about the buyer’s bank account in a special way. It is enough to insert this card into the cash register - and the computer itself will transfer the required amount from the buyer’s account to the store’s account (more precisely, it will send a request to the bank, and the bank’s computer will make the necessary transfers). With this method, the cashier spends seconds serving one customer, and there are simply no queues.
28.2. PENETRATION OF COMPUTER INTO ALL SPHERES OF LIFE
The computer can be used not only for work, but also for leisure. The advent of computers also led to a revolution in gaming. Number computer games games that have appeared over the past two decades have already surpassed the number of games invented by mankind in the entire previous history of civilization. A significant proportion of the world's computers are used for gaming.
Computers are invading every area of life. Even computer crimes appeared (when, for example, the accrual program wages transfers unearned money to the account of the program author). Another example: several years ago, one of the VAZ programmers, as a sign of protest against low wages, introduced a deliberate error into the program and thereby stopped the main conveyor for several days (remember paragraph 23.2). As a result, the plant suffered great material damage, not comparable to the salary of all VAZ programmers combined, and the programmer was disqualified and transferred to workers.
28.3. ERRORS IN COMPUTER APPLICATIONS
We talked a lot about the advantages of computers and their role in the life of society. However, like any other human invention, a computer can bring not only benefits, but also harm. The idea of when it is inappropriate to use computers and what the main errors in their applications are is an important part of computer literacy. Therefore, we will briefly list a few such cases.
1. Transformation of computers from a means to an end. The use of computers in itself does not serve as a sign technical progress. Quite the contrary - progress is often associated not with the improvement of the existing one, but with the transition to new technology. For example, the transition to precision casting eliminates the finishing machining of parts and makes the computer that controls this processing unnecessary. The desire to “introduce computers” can hinder such a transition and thereby slow down scientific and technological progress.
Likewise, cancel additional fee for intercity telephone conversations may make unnecessary a computer that calculates their cost depending on the duration of the call and the distance between cities. The construction of tunnels and overpasses can eliminate traffic lights and computerized traffic control. Transition to new principles of remuneration, taxation and social security may make it unnecessary to calculate salaries on a computer, etc.
2. Errors in algorithms. The computer only executes algorithms. These algorithms may be made with errors or based on incorrect ideas about reality. For example, one of the first computer systems The US air defense (60s) raised the alarm on its very first watch, mistaking the Moon rising from the horizon for an enemy missile, since this “object” was approaching US territory and did not give signals that it was “friendly”.
3. Incorrect input data. The result of a computer depends not only on the algorithm, but also on the information being processed. Errors in source data are no less dangerous than errors in algorithms. Several years ago, for example, a plane with tourists on board crashed in Antarctica because the wrong coordinates of the take-off airport were placed in the flight control computer and the computer incorrectly calculated the flight altitude over the mountains.
4. Computers are not omnipotent. Not every information processing problem can be solved using a computer. There are problems for which solution algorithms are currently unknown. For example, there are still no acceptable algorithms that would allow one to distinguish a cat from a dog in a photograph or to correctly translate piece of art from one language to another. It also happens that an algorithm is known, but it cannot be executed, since even the fastest computers will need millions of years to complete it (an example of such a problem is an error-free game of chess). Therefore, the idea that if a person does not know the solution to a problem, then it must be “put into a computer” and the computer will give the answer is deeply mistaken.
5. Underestimation of the social consequences of computerization.
Finally, and most importantly, the use of computers changes people's lives. Therefore, the question of new applications of computers should first of all be considered from the point of view of social consequences, and not from the position of “can computers do it” or “can’t”, is it beneficial or not. Many stages of informatization of society have difficult to predict social consequences. The introduction of automatic factories requires the transfer of a significant part of the workforce from the production sector to the service sector. If work in the service sector is considered less prestigious in society, such a transfer may cause social tension. Organizing work from home allows you to increase the amount of free time, but destroys the sphere of communication with colleagues. The spread of computer games leads to the fact that children develop faster, but spend less time outdoors and communicate less with each other. In many cases, computers simply should not be implemented. For example, one should not entrust computers with human affairs related to making moral and ethical decisions when raising children, formulating goals for the social development of society, or establishing the guilt of those accused of a crime.
END OF BOOK FRAGMENT

1.7. INTRODUCTION TO THE SCHOOL SUBJECT “FUNDAMENTALS OF INFORMATION SCIENCE AND COMPUTER ENGINEERING”

The mastery of the production of microprocessors, which led to a radical change in the structure of the computer park and the widespread distribution of computers for mass use (microcalculators, personal computers, multi-terminal complexes based on small computers, interactive computing systems, etc.), created the necessary prerequisites for accelerating the processes of school computerization. A qualitatively new stage in the development of domestic computer technology, due to the advent of microprocessors, began in the second half of the 1970s. This gave rise to a new wave of research on the problem of introducing computers and programming in schools. Under the leadership of the outstanding Soviet mathematician and programmer A.P. Ershov, a “Siberian group of school informatics” was formed at the computer science department of the Computing Center of the Siberian Branch of the USSR Academy of Sciences. The main program provisions of the apologists of this group (A. P. Ershov, G. A. Zvenigorodsky, Yu. A. Pervin), which largely served as a basis for the development of the national school computerization program, were published in 1979 in the conceptual work “School Informatics (Concepts , state, prospects)".

By the first half of the 1980s. in the methodological science and school practice of the country, significant theoretical and practical baggage has been accumulated, incorporating the experience of the previous three decades. Thus, all the necessary prerequisites were created for active government solutions to the problem of computerization of school education. Characterizing the peculiarity of the new moment, A.P. Ershov noted: “Now, after the advent of microprocessors, the question of whether or not to have a computer in school is already becoming scholastic. Computers are already in schools and will come there in increasing numbers, and very active intellectual and organizational work is required from us in order to give this process a controlled and pedagogically motivated character.”

A. P. Ershov (1931-1988)

The impetus for the development of specific organizational and methodological measures in the field of school computerization was the party and government resolution “Main directions for the reform of secondary and vocational schools”

(1984) One of the main provisions of the school reform of that time was the clearly declared task of introducing computer science and computer technology into the educational process of schools and ensuring universal computer literacy among young people. At the end of 1984, under the joint supervision of the Computing Center of the Siberian Branch of the USSR Academy of Sciences and the Scientific research institute Contents and Methods of Teaching (Research Institute of Science and Education) of the Academy of Pedagogical Sciences of the USSR, with the involvement of the most prominent computer science teachers from various regions of the country, work began to create a program for a new general education subject for secondary schools, called “Fundamentals of Informatics and Computer Science.” By mid-1985, such work was completed and approved by the USSR Ministry of Education. Subsequent government decisions also approved the main strategic path to quickly solve the problem of developing computer literacy among young people - introduction to high school the subject “Fundamentals of Informatics and Computer Science” as compulsory, as well as the specific date for the introduction of the new subject - September 1, 1985. In a short time, following the program, trial textbooks for students, books for teachers, were prepared. The outstanding Soviet mathematician and programmer, Academician of the USSR Academy of Sciences A.P. Ershov, supervised and took an active personal part in the implementation of the entire complex of these works. On the part of the SRI SiMO, coordination and editorial work was carried out by A. A. Kuznetsov, who at that time headed the computer science laboratory. A large group of authors, formed from employees of the Research Institute of Education and Science, as well as well-known specialists from various regions of the USSR, took part in the creation of these first domestic educational books on the school course of computer science and methodological guides for teachers: S. A. Beshenkov, M. V. Vitinsh, Ya E. Golts, E. A. Ikaunieks, A. A. Kuznetsov, E. I. Kuznetsov, M. I. Lapchik, A. S. Lesnevsky, S. I. Pavlov, Yu. A. Pervin , D. O. Smekalin, R. V. Freivald. At the same time, when preparing and editing texts according to textbooks for students, A. P. Ershov systematically enjoyed the support of a qualified group of “shadow” co-authors from Moscow State University, which included A. G. Kushnirenko, G. V. Lebedev, A. L. Semenov, A. X. Shen, whose influence on the content and the final edition of the books was very noticeable. Subsequently, this group was organized by A.P. Ershov into a team of authors, which, a short time after the release of the first manuals, released its own version of the trial textbook.

Evidence of the state's attention to the problem of school computerization was the establishment of a new scientific and methodological journal “Informatics and Education” (INFO), the first issue of which was published at the beginning of the school year (1986-1987). This scientific and methodological journal remains extremely important to this day. modern system education with a special periodical covering scientific, methodological, didactic, technical, organizational, socio-economic, psychological and pedagogical issues of introducing computer science and information technologies into the field of education.

To teach a new subject during the summers of 1985 and 1986. Intensive course training was carried out for teachers, mainly from among working teachers of mathematics and physics, as well as educational organizers. This contingent was replenished through accelerated in-depth training in the field of computer science and computer technology for future young teachers - graduates of physics and mathematics faculties in 1985-1986. At the same time, the Ministry of Education of the USSR took operational organizational and methodological measures to organize regular training of teachers of computer science and computer technology on the basis of physics and mathematics departments of pedagogical institutes.

In order to more accurately understand the nature and level of complexity of the problems that needed to be solved in a short time in the field of staffing for the introduction of the subject of computer science in schools or, more broadly, in the field of computerization of the school as a whole, it is worth recalling what the actual level of training in the field of computer science was and computers of teachers working in the mid-1980s. in schools of the USSR.

For the first time, a very short introductory course in computer programming with the exotic name “Mathematical machines and programming with a computational workshop” appeared in the curricula of physics and mathematics departments of pedagogical universities in the 1963-1964 academic year. In 1970 in educational plans these educational institutions are introducing an updated course “ Computing machines and Programming" (about 50 hours), aimed at introducing computer programming, although the recommended curriculum for this course clearly did not correspond to the promising directions for the development of the programming discipline that had already emerged by that time.

The next official version of the synthetic course program “Computational Mathematics and Programming” (1976) already allocated about 70 hours for programming and assumed, in particular, familiarization with the universal high-level language ALGOL-60. It should be taken into account that the highest level for that time technical support, and for a very small number of pedagogical universities in the country, there was the presence of one or two small computers such as “Nairi”, “Promin”, “Mir”, etc. etc., focused only on the use of their own languages, which did not allow the curriculum to be fully implemented. By the end of the 1970s. In Russian pedagogical universities, only four departments of programming and computational mathematics were opened (Moscow, Leningrad, Sverdlovsk, Omsk), and the first personal computers (domestic PCs of the Iskra, DVK, Elektronika series) began to appear in very limited quantities and in a very limited number of pedagogical universities, almost only by the mid-1980s.

From the above, it clearly follows that by the time computer science was introduced into secondary schools (1985), the level of computer training of the graduates of physics and mathematics departments of pedagogical universities working at the school at that time for the most part did not in any way meet the requirements of teaching the new JIVT course.

The reasons are obvious:

Pedagogical education did not provide education in the field of computer science, but was focused only on familiarization with the beginnings of programming, and at a much more backward ideological level than the one at which computer science courses began to be introduced in schools;
teacher training in programming was

purely educational in nature, it was not

focused on teaching this subject to schoolchildren (there was no such task).

It is obvious that the efforts undertaken in the second half of the 1980s. state and regional education authorities, the most decisive and prompt organizational and methodological measures to ensure urgent additional training of teachers for teaching computer science and computer technology from among working mathematics and physics teachers were suitable only as urgent measures of the first stage of introducing JIVT into schools. As for the establishment of regular training for computer science teachers and organizers of school computerization on the basis of physics and mathematics departments of pedagogical institutes, as well as the implementation of subsequent measures to bring computer education into line with teachers of other school disciplines, these measures should have been based on solid scientific and methodological justifications and developments .

See also the fundamental publication: Ershov, A.P. Selected works. Novosibirsk: Nauka, 1994. P. 354.

LITERATURE 1. Fundamentals of computer science and computer technology: educational and practical manual of the series “ Distance learning". Ed. A. N. Morozevich. – Minsk. : BSEU, 2005. 2. Computer information technologies: workshop for students. correspondence forms of training /under general Ed. Sedun A. M., Sadovskoy M. N. - Minsk: BSEU, 2010. 3. \Research\Monitor\Ucheb. M\Natural sciences\KIT\Sosnovsky O. A. \Lecture course on KIT 1

Topic 1. SUBJECT AND BASIC CONCEPTS OF CIT Information technology is a complex of interrelated scientific, technological, and engineering disciplines that study methods for effectively organizing the work of people involved in processing and storing information; computer technology and methods of organizing and interacting with people and production equipment, their practical applications, as well as social, economic and cultural problems associated with all this. Stages of development of information technology 1. Manual 2. Mechanical 3. Electrical 4. Computer 5. Mobile 2

Classification and general characteristics KIT Computer IT - ways of using computer technology, software, communication systems and data subject to reception, transmission, processing and storage and reflecting reality or intellectual activity in all spheres of society. Basic technologies are technologies that are implemented at the level of interaction of elements of computer systems. Applied technologies implement standard procedures for processing information in various subject areas. They are divided into two categories: - products and services. 3

Basic concepts of CIT Information is a set of data and methods adequate to these data. Data - information presented in a form convenient for transmission, interpretation and processing. Economic information is a set of information used for planning, accounting, control, regulation in the management of macro- and microeconomics. 4

Types of information 1) By area of knowledge: – – – – technical; legal; economic; sociological; physical; political; etc. 2) According to the form of presentation: – Symbolic (letters, numbers, signs); – Text (texts are symbols arranged in a certain order); – Graphic (various types of images); – Sound; 5

Properties of information Adequacy – correspondence of the information received to its true content. Reliability is compliance with objective reality. Completeness - sufficiency for understanding and decision-making. Objectivity – independence from anyone else’s opinion or judgment. Availability – possibilities of obtaining it. Relevance – relevance to the current time 6

Information Encoding Information Encoding is the process of representing information in the form of code to ensure understanding, storage and processing in a form convenient for the processor. Code – set symbols to present information. A bit is the minimum unit of information, because it is impossible to obtain information less than 1 bit. (English bit - short for binary digit - binary unit or digit). A group of 8 bits of information is called a byte. If a bit is the minimum unit of information, then a byte is its basic unit. 7

Number encoding The minimum number of binary digits used is 8, which is 1 byte. 8 binary digits allow you to encode numbers from 0 to 255. 0 0000 1 0000 0001 2 0000 0010 3 0000 0011 4 0000 0100 … … 255 1111 8

If one of the bits is allocated for storing the sign of the number, then the same 8 bits will provide the ability to encode numbers from 128 to 127. To encode real numbers, when it is necessary to take into account the decimal part of the number, a special form of representation is used - floating point. X=M*2 P, here M is the so-called mantissa, P is the order. 9

Text data can be encoded using binary code and text information. Eight bits are enough to encode 256 various characters(all characters of the English and Russian alphabets, both lowercase and uppercase, as well as punctuation marks, symbols of basic arithmetic operations and some generally accepted special characters, for example "@".) The US Standards Institute (ANSI - American Standard Institute) introduced the system ASCII encoding. The ASCII system has two encoding tables - basic and extended. The basic table fixes code values from 0 to 127, and the extended table refers to characters from 128 to 255. 10

Encoding Graphic Information Presentation of Graphic Data Vector graphics Raster graphics A set of lines, vectors, points Many points of different colors and brightness When scaling the image does not deteriorate When scaling the image is distorted Editing is inconvenient Editing is convenient 12

Digital representation of sound. Sound can be described as a collection of sine waves of a certain frequency and amplitude. The frequency of the wave determines the pitch of the sound, and the amplitude determines the loudness of the sound. 13

Information society is a society in which the majority of workers are engaged in the production, storage, processing and sale of information, especially its highest form - knowledge. Informatization of society is the widespread implementation of a set of measures aimed at ensuring the full and timely use of reliable information and generalized knowledge in all socially significant types of human activity. 14

Topic 2. TECHNICAL SUPPORT OF KIT Classification of VT equipment Based on the principle of operation: – Analog (AVM); – Digital (DVM); – Hybrid (HVM). By purpose: – Universal (for solving various engineering and technical problems: economic, mathematical, information, etc., characterized by the complexity of algorithms and a large volume of processed data.); – problem-oriented (to solve a narrower range of problems related to management technological processes); – Specialized (for solving a narrow range of tasks or implementing a strictly defined group of functions). 15

By size: – Super computer (Cray 3, Cray 4, “SKIF”); – Mainframe computers; – Small computers (for process control, CM 1, 2, 3, 4, 1400): – micro computers: Personal computers (Universal single-user), Multi-user (Universal multi-user), Workstations (Specialized single-user); Servers (Specialized multi-user). 16

By stages of creation - 1st generation - 50 years - on electronic vacuum tubes; – 2nd generation – 60 years – on discrete semiconductor devices(transistors); – 3rd generation – 70 years – on semiconductor ICs (hundreds of thousands of products); – 4th generation – 80s – on large and extra-large ICs (tens of thousands – millions of units); – 5th generation – 90s – with dozens of microprocessors; – 6th generation – optoelectronic computers of neural structure (tens of thousands of MP). The generation of computers is determined by the element base (lamps, semiconductors, microcircuits of varying degrees of integration), architecture and computing capabilities. 17

The founders of computer science are rightfully considered: Claude Shannon - the creator of information theory; Alan Turing - mathematician who developed the theory of programs and algorithms; John von Neumann is the originator of the computing device design that still underlies most computers today. Norbert Wiener - mathematician, founder of cybernetics - the science of control as one of the main information processes. 18

Organization of a computer according to John von Neumann Formulated in 1945. Computer structure according to John von Neumann 1) information input/output devices; 2) computer memory; 3) processor, including a control unit (CU) and an arithmetic-logical unit (ALU) 19

Computer memory consists of two types of memory: internal (RAM) and external (long-term) memory. RAM is electronic device, which stores information while powered by electricity. External memory– these are various magnetic media (tapes, disks), optical disks. The arithmetic logic unit performs arithmetic and logical operations over the data entering it. 20

Principles of computer operation according to John von Neumann 1. The principle of binary coding. 2. Principle program control. A program is an ordered set of commands. 3. The principle of memory homogeneity. Commands (programs) and data are stored in the same memory. 4. The principle of targeting. Memory consists of numbered cells accessible by the processor. Neumann's ideas were implemented in 1949 by the Englishman 21 Maurice Wilkes

Types of computer system architectures Computer architecture is a set of general principles for organizing hardware and software and their characteristics, which determines the capabilities of the computer in solving relevant user problems. The architecture defines the principles of operation, information connections and interconnection of the main logical nodes of the computer. 22

Single-processor computing system - (von Neumann architecture): - one arithmetic-logical device through which the data flow passes; – one control device through which a flow of commands passes. Multiprocessor computing system with shared memory: – several processors – can process several data streams and several command streams in parallel. – A special case of architecture with parallel processors Multi-machine computing system: – several computers that do not have common RAM; – each computer has its own (local) memory and classical architecture.

Architecture modern processors 1. CISC (Complex Instruction Set Computing) - an architecture based on a complex set of instructions. (founder of IBM) 2. RISC (Reduced Instruction Set Computing) post-CISC architecture, built on the basis of a reduced set of instructions 3. VLIW (Very Long Instruction Word) Architecture-compromise between CISC and RISC; post-RISC architecture. 24

Classification of personal computers Personal computer (PC) – small in size and cost, desktop universal micro. A computer intended for individual use. A. By purpose: – household – general purpose– professional. B. By microprocessor type: – Intel: 8008, 80486, Pentium... – AMD: K 6, K 7 Duron, K 7 Athlon... 25

C. By design: – stationary – portable: portable (diplomat) notepad (book) pocket (150 x 80 mm) electronic secretaries (up to 0.5 kg) organizers (up to 0.2 kg). E. By platform type (PC compatibility): IBM – compatible PCs (75%): – IBM – Compaq Computer – Hewlett Packard (HP) – Dell – EU, Spark, Neuron DEC – compatible PCs (3, 75%): DEC , Macintosh, DVK 26

D. By PC manufacturing companies USA: France: – IBM – Compaq Computer – Apple (Macintosh) – Hewlett Packard (HP) – Dell – DEC (Digital Equipment Corp.); UK: – Spectrum – Amstrad; – Micral; Italy: – Olivetty; Japan: – Toshiba – Panasonic – Partner; PC of Russia (USSR, CIS): – – DCK EU Iskra Neuron. 27

Principle of open architecture 1. PC structure is a composite system of individual elements. 2. Availability of interfacing between elements: Development of individual PC devices by independent manufacturers; Software development by independent manufacturers. As a result, the following opportunities arise: Reducing the cost of a PC; Possibility of self-configuration of the PC by the user; Gradually expanding the capabilities of your PC; Possibility of constant updating of the PC composition... 28

Typical PC kit. Purpose and characteristics of the main blocks 1. System unit 2. Keyboard 3. Monitor 4. Mouse 29

The system unit includes: a system (motherboard) board, where the processor, RAM and permanent memory are located, which are made in the form of large integrated circuits (LSI). adapters, controllers and ports - devices that provide communication with external devices; drives for hard magnetic disks (HDD), floppy magnetic disks (FLMD), optical disks (ODD); power unit. thirty

Monitor, keyboard, printer Using the keyboard, the user enters symbolic and numeric information into the PC. The monitor (screen) is used to display information in a user-friendly form (with a cathode ray tube; liquid crystal monitors). Monitor sizes are measured in inches (||) diagonally. In addition to sizes the most important characteristic monitor is the refresh rate - the higher the refresh rate, the better the image quality. Best quality Monitors from LG and 31 Samsung differ.

The mouse allows for graphical WINDOWS environment control the cursor on the monitor screen, as well as launch the execution of commands and programs (mechanical and optical). Using a printer, information is output to paper media (laser, inkjet (ink), matrix (needle). Hewlett-Packard, Epson, Lexmark, Xerox. 32

Processor (microprocessor) Main components of processors: 1. Arithmetic logic unit (ALU): – arithmetic functions (addition, multiplication...); – logical functions (comparison, masking...) 2. Control device (CU) – for supplying control pulses. 3. Registers – high-speed memory cells to speed up program execution: – general purpose registers (GPR) – store data; – control registers – store commands. 4. Cache memory – ultra-high-speed memory for copying data from the RAM. (cache memory of the first (L 1) and second (L 2) levels. L 1 has a volume of 128 KB, L 2 up to 1 MB) 5. Bus control circuit - for communication with other K devices via the system bus. 33

The system bus ensures the pairing and communication of all PC devices with each other. Modern system buses have a width of 64 bits and a clock frequency of up to 800 MHz. The capacity of a bus is determined by its clock frequency and bit depth. 34

Inner memory designed for storing and exchanging information. The internal memory contains two types of storage devices: read-only memory (ROM - read only memory) - used to store unchangeable (permanent) program and reference information, allows you to quickly only read the information stored in it (you cannot change the information in the ROM!). random access memory (RAM) – designed for operational recording, storage and reading of information (programs and data) directly involved in the information computing process performed by the PC in the current period of time. 35

BIOS module is the most important permanent memory chip (Basic Input/Output System). BIOS is a set of programs designed to automatically test devices after turning on the computer and loading the operating system into RAM 36

External PC memory 1. Hard magnetic disk - hard drive, HDD, HDD (hard disk drive): 1. capacity - 1. 2, 5, 10, 37, ... 100 ... GB; 2. Number of plates (up to 10 pieces) 3. Rotation speed of the plates – from 5,400 to 10,000 rpm. 4. The main manufacturers of HDDs are IBM, Seegate, Toshiba, Fujitsu, Samsung. 2. Flexible magnetic disk - NGMD, FDD (floppy disk drive): 1. capacity 1.4 MB, 120 MB; 2. speed ~360 rpm. 3. Optical disc– GCD: 1. CD-ROM(Compact Disc Read Only Memory), CD-R(Compact Disc Recordable), CD-RW(Compact Disc Rewritable): 650 – 800 MB; 2. DVD (Digital Versatile Disk): single-sided 4.7 GB, double-sided 9.4 GB, double-layer 8, 5 and 17 GB, respectively; 3. normal performance - 150 KB/s, taking into account multiplication - 4 x, 8 x, 32 x... 48 x. 4. Flash memory: 1. capacity up to 1 GB and above; 2. rewriting from 10 thousand to 1 million times 3. storage for decades. 37

PC configuration refers to the composition and characteristics of the devices included in this computer. The configuration is selected depending on the tasks that need to be solved by the PC. The PC configuration can be set as follows: Intel Core 2 DUO 6700, RAM DDR 2 4 Gb, HDDSeagate 500 GB 7200, Video Nvidea Ge. Force 8800 GTX 768 Mb, Net 3 COM 10/1000, DVD -R/RW, + scroll optical, Samsung TFT 22|| (1600 x 1200 x 75 Hz), HP Laser. Jet 1320 38

Factors and parameters affecting PC performance 1. Software factors; 2. Hardware parameters: processor type; volume of internal and external devices; performance of external devices connected to the PC. 39

Development trends technical means KIT 1. 2. 3. 4. 5. 6. 7. 8. Transition to computing systems. Development of super computers. Development of subminiature computers. Development of computer neural structure. Use of optical and wireless communication. Development of multimedia tools for communication in food. language. Increasing storage media capacity. Computer intellectualization. 40

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EXERCISE 1

Characteristics of the Windows file system. Creating user folders. Explorer program, its meaning. Working with files and folders; performing operations on a group of files; managing the display of information on panels (full and brief information about folders and files; organizing by name, type, date; displaying the folder structure) and other features. Search program, its meaning and functionality, search criteria for files and folders.

File Windows system

Information in a computer is stored in memory or on various media, such as flexible and hard disks, or CDs. When you turn off the computer's power, information stored in the computer's memory is lost, but information stored on disks is not. To work confidently at a computer, you should know the basic principles of storing information on computer disks; for this, let’s look at the concept of a file system.

A file system is a set of conventions that define the organization of data on storage media. The presence of these conventions allows the operating system, other programs and users to work with files and directories, and not just with sections (sectors) of disks.

The file system defines:

How files and directories are stored on the disk;

What information is stored about files and directories;

How can you find out which parts of the disk are free and which are not;

Format of directories and other service information on disk.

To use discs written (partitioned) using some file system, operating system or special program must support this file system.

All information intended for long-term use is stored in files. A file is a sequence of bytes, combined according to some characteristic and having a name. The system for storing and working with files on a computer is called file system. For convenience, files are stored in various folders located on disks. Your computer may have multiple disks installed. Any floppy disk HDD, CD, Digital Video Disc or network drive we will simply call it a disk, since the principles of organizing file storage on them are identical. Each disk is assigned a letter of the Latin alphabet from A to Z, and there are some designation rules. The letter A stands for a floppy disk, and the letter C stands for the main drive of your computer where the Windows system is located. The letter D and subsequent letters indicate the remaining drives. The drive letter is followed by a colon “:” to indicate that the drive letter is a drive, such as A: or C:. In addition to the letter, each drive has its own unique name, also called a label. Most often, when specifying a drive, a label and letter designation in brackets are used. For example, Main (C:) means that the main drive of your computer is labeled Main.

Each disk contains many different files. Any file can be located either directly on the disk or in an arbitrary folder, which in turn can also be located in another folder.

The fact that files can be located in different folders allows you to place several files with the same names on the disk. The structure of storing information on a disk, in which some folders can be located in other folders, is called hierarchical or tree-like. This structure is really similar to a real tree, on which each leaf represents separate file, and the branch is a folder. The leaf can grow either directly from the trunk or from any branch. It is possible that one branch extends from the trunk, another from it, and then leaves are located on it. To uniquely identify a specific file, you need to specify its name and location, that is, the name of the disk and the names of all subfolders in which it is located. this file. Often the exact location of a file on disk is called full name file or path to the file.

When specifying a file path, folder names are separated from each other and from the drive name using the backslash character “\”, for example, C:\My Documents\My Drawings\My Young Me.jpg. This entry means that a file named Young Me.jpg is located in the My Pictures folder. This folder is located in the My Documents folder located on the C: drive.

Please note that in the example considered, the file name contains a dot character and seems to consist of two parts - before the dot and after it. The part of the name after the period is called the extension and is used to indicate the type of information stored in the file. For example, the doc extension stands for text file, wav is a file containing sounds, and jpg is an image. Windows doesn't show many file extensions, so it's likely the file in our example will just be called Young Me, but Windows will know it's working with an image.

An important concept in Windows is the concept of a shortcut. For any Windows object can be referenced from another location. Such a link is called a shortcut. For example, a frequently used picture is located in a folder. For quick access To this picture from different places, you can place labels in these places containing the address of the real location of the picture. No need to copy programs and data to different folders, it is enough to simply place shortcuts linking to required file, in several places. All these shortcuts will point to the original file. Removing or moving a shortcut does not affect the location original file, so using shortcuts can provide additional protection.

Creating a new folder

To create a folder on the desktop, right-click on free space desktop and select the Folder command from the Create submenu of the context menu that appears.

If we want to create a folder in an already existing folder, we will open the desired folder and perform similar actions. This will create a folder named New Folder. We can change the name if necessary. To do this, just specify the name of the new folder and press Enter.

Explorer program

One of the most important programs in Windows is the Explorer program. It allows the user to manage files and programs stored on computers and the network.

The Explorer program window (Fig. 1) is divided into two parts: the left one displays a hierarchical tree of folders and devices, and the right one displays the contents of the selected folder or device.

Launching Explorer

There are several ways to launch the Explorer program. However, the easiest way to do this is to use the Start button --> Programs --> Explorer.

We can get a similar result by right-clicking on the icon of any folder or on the Start button and selecting Explorer from the menu that opens. (This command is also present in the context menu of the My Computer, Network Neighborhood, Outlook Express and Cart.)

Hierarchical tree of folders and devices

The Explorer program window consists of two parts: on the left, by default, the All Folders panel is displayed, which contains a hierarchical tree of folders and devices, on the right - the contents of the folder (or device) marked in the left part of the window. If, for example, you mark the C: drive icon on the left side of the window, the contents of this drive will be displayed on the right side.

Rice. 1. Explorer window

On the left side of the Explorer program window, a hierarchical tree of folders and devices is always displayed, which allows you to display on the screen the contents of any storage device or folder available to the system with a mouse click.

Working with the contents of the Explorer window

To display icons of folders contained on a storage device or in another folder in the hierarchical tree of the Explorer window, you must click on the “+” symbol next to the icon of the corresponding storage device or folder. After this, instead of the “+” symbol, the “-” symbol will appear. By clicking on it, we will do the opposite operation - we will hide the icons of the folders contained on this device or in this folder in the hierarchical tree.

To display the icons of all folders, including their subfolders, in the hierarchical tree, you must press the [*] key on the numeric pad of the keyboard. It should be noted that the time after which all subfolders will be opened depends on their number. You can close open subfolders by pressing the [-] key on the keyboard.

Back, Forward and Up buttons

To open the folder from which you moved to the current folder, you need to press the Back button or use the combination Alt keys + <--.

To return to the previous folder, we just need to click the Forward button on the toolbar or use the key combination Alt + -->.

To open a folder in the Explorer window that is located in the tree of folders and devices one level higher than the current one, you must press the Backspace key or click the Up button on the toolbar.