Education system of the Stavropol region. Computer encyclopedia “Cyril and Methodius Briefly about the product
Only a few decades separate us from the time when electronic computers occupied entire halls, and the people who worked on them were considered almost geniuses. How could you not get confused in hundreds of thousands of wires and terminals?! Then none of us could have imagined that some twenty years would pass and computers would become personal, that they would appear in our home and, moreover, would become an integral part of our lives. The number of computer users is growing day by day. Of course, none of them claims to be a software engineer, but everyone in whose house a personal computer “lives” certainly does not consider himself an amateur in relation to his electronic friend.
Yes, indeed, for many people a computer is a reliable friend. With its help, people quickly explore the world around them, gain knowledge, and reach new heights. For some, a computer has become simply necessary as a working tool. Life has brought us to this simple conclusion: if we want to realize ourselves to the fullest, we must be computer literate. Lack of computer user skills is often perceived as a disadvantage. Although voices are increasingly heard comparing a computer to a Trojan horse. They argue that people are simply unable to appreciate the danger that computerization poses, that they cannot take into account the incredible speed of technological improvement in machines. For example, in Japan there is already a computer that can perform 300 billion operations per second, and very soon a machine with a speed of 1 trillion per second will appear. Many people still believe that a computer is a dangerous invention that, with its artificial intelligence, can influence human consciousness. But even they cannot deny the simple truth: the computer has firmly entered our lives, and the future of humanity lies behind it.
The current situation requires us to be certain in our attitude towards technology, intelligence and creativity. Remember Isaac Asimov's Three Laws of Robotics? “Think about how to maintain the goodwill of your creation and not lose the status of its creator.” Of course, such thoughts never occur to many of us. We would like to gain basic knowledge about working with a personal computer, so that we are not overcome by an inexplicable fear of this smart machine. But believe me, in order to become an ordinary, ordinary, and then an experienced user of a personal computer, no brilliant intellectual abilities are required.
On the pages of this book, all the necessary knowledge for novice users is presented in a simple and accessible form. We promise: from the very first page your awe of the PC will begin to dissipate, and by the fifth or sixth it will completely disappear. You will see that there is nothing difficult in communicating with a computer, that even a preschool child can easily master it. The book describes the successive stages of getting to know a computer, starting with its design and practical tips when buying it. With the help of the book, you will learn how to work with basic programs, text, graphics, photographs, music files, learn how to burn CDs and DVDs, access the Internet, and besides this, you will receive a lot of useful tips and necessary information. You will soon be surprised to realize that you have become a confident user of your personal computer. Good luck, dear reader!
What is a computer
Maybe you think you have enough knowledge about a machine called a computer. But don't rush to skip the first chapter, especially if you are a novice computer user. We can bet that much of the information you will glean from this chapter will turn out to be completely useful and even useful for you.
Let's start with the etymology of the word "computer". It comes from the English “compute”, which means “calculation”. But the functions of a computer are not limited to electronic calculations, like a calculator.
The capabilities of an electronic machine are hundreds of times wider and, with the rapid development of new technologies, they are growing every day. A computer can perform operations not only with numbers, but also with any information - text, sound or graphic image. Of course, all this is first converted into digital form. The computer, in addition, can formulate commands and use them to control various external devices - a monitor, a printer, speakers, etc.
You think you know what a computer looks like, but the device you purchased and installed on your desk is far from the only member of the computer family. In fact, there are already a great many such smart machines. And what’s interesting is that most of them in appearance are not at all similar to the personal computer we are used to. It is impossible to name any branch of industry or sphere of human activity where a computer is not used in one form or another. It is with its help that airplanes, cars, submarines, and spaceships are controlled in the modern world. Only such computers are called special.
In everyday life, of course, they use completely different computers, which are usually called personal computers - PCs, and the English abbreviation for such machines is PC. There are handheld or pocket computers - PocketPC, PalmTop, portable - laptops. And in this book we will talk about desktop personal computers (Fig. 1).
Rice. 1. Types of modern personal computers: a – pocket computer; b – laptop; c – desktop personal computer
You've probably heard of IBM-compatible desktop personal computers. IBM is the name of a well-known company producing personal computer equipment. In the recent past, IBM products were the most popular and widespread in the computer market. Currently, computers from this company have practically disappeared from sale, but the concept of IBM compatibility still sounds relevant. At the dawn of the computer era, most manufacturing companies kept all the components of their machines in the strictest confidence. This was called the principle of closed architecture. And IBM, unlike others, provided information about components to everyone and, moreover, called on competitors to also use the principle of open architecture and produce similar computers with similar components. IBM took a leading position in the computer equipment market and for a long time enjoyed the unlimited trust of consumers. Gradually, specialists from other manufacturing companies appreciated the advantage of IBM-compatible models, mastered their production and began to develop their own versions of components, which often turned out to be of better quality than the products of the company that gave birth to modern PCs. Thus, IBM products were very quickly forced out of the market by competitors. Only the name of the company continues to live, since computers from modern well-known companies are still called IBM-compatible.
All desktop and laptop PCs that exist today are IBM compatible. The exception is Apple computers, but in our country they are used only in printing, and even then extremely rarely. Initially, handheld computers were not IBM-compatible, but recently modifications have been developed that allow the installation of a reduced version of Windows.
Contents of the article
COMPUTER, a device that performs mathematical and logical operations on symbols and other forms of information and produces results in a form that can be understood by humans or machines. The first computers were used mainly for calculations, i.e. addition, subtraction, multiplication, division, etc. Today, computers are used to solve numerous and varied other tasks, such as word processing, graphics, and processing large amounts of information.
Machines that perform simple calculations are usually called calculators and usually operate using rigid algorithms using buttons and keys. Although computers are often controlled by commands entered from the keyboard, their basic functions are usually controlled by commands stored within the machine, known as software, or programs. Both calculators and computers operate by manipulating symbols of some kind.
TYPES OF COMPUTER
There are two main types of computers: analog and digital. They differ in the principle of construction, the way of internal presentation of information and the response to commands. An analog computer works by simulating what it calculates; it does this by continuously varying its characteristics. Such a reaction is an analogue of the process embodied in the problem with which it deals. A universal analog computer contains resistors, capacitors and inductors, between which connections can be made to reflect the conditions of a particular task. Digital computers change the values of binary numbers, or bits, that represent the elements of the problem to be solved. Numbers in a digital computer can also be used to represent other symbols, such as letters, plus and minus signs, etc. Digital computers, unlike analog ones, operate in finite steps. Hybrid computers, as their name suggests, combine the characteristics of the two main types mentioned above.
Analog computers.
There are various types of such computers. Analog computers are “programmed” by specifying the physical characteristics of their components. In some computers, this is usually done by including or excluding certain components from the circuits connecting these components with wires, and changing the parameters of variable resistances, capacitances and inductances in the circuits. The operating program of, for example, a car transmission is changed by moving the gear shift knob, which causes the fluid in the hydraulic drive to change the direction of flow, producing the desired result.
In addition to technical tools such as automatic transmissions and music synthesizers, there is a tendency to entrust analog computers with specific practical computing tasks. There are large general-purpose analog computers.
Digital computers.
Almost all digital computers are electronic. They all have somewhat similar components for receiving, sorting, processing, and transmitting information and use a relatively small number of basic functions to perform their tasks. The most important characteristics of digital computers are speed, ability to work in repetitive ways, reproducibility of results and versatility. Thanks to these characteristics, digital computers find a wide range of applications ranging from wristwatches to spacecraft.
There are four main types of digital computers: supercomputers, large computers, minicomputers and microcomputers. (A personal computer can be considered a general-purpose microcomputer.) All digital computers have approximately the same design, but differ in size and speed of calculations.
Personal computers.
Personal computers are smaller and less varied than digital mainframes. However, there are more personal computers than general purpose digital computers of all other types combined, and their share is constantly increasing. Therefore, it is worthwhile to dwell in more detail on the main characteristics of personal computers.
Typically a personal computer contains a single microprocessor chip that serves as its central processing unit ( see below). Today's personal computers have more limited capabilities than the latest minicomputers and large computers, but are already more powerful than the large computers of the 1980s. The limitations are largely related to cost: as the cost of basic components decreases, more powerful personal computers are released. A powerful and more expensive type of microcomputer, called a workstation, appeared in the mid-1980s. These stations use the fastest microprocessors and high-resolution graphic displays. Many of them use RISC processors ( see below). As the capabilities of personal computers increase, the distinction between a personal computer and a workstation, as well as between a microcomputer and a minicomputer, is blurring.
Much of what big computers do can be done on personal computers, although usually not as quickly. Large computers are required for some complex information processing functions; For other, simpler functions, such as routine word or document processing, publishing procedures, and simple accounting transactions, personal computers are often more efficient than large machines.
ARCHITECTURE
The term "architecture" in relation to a computer means much the same as in relation to a structure. For example, digital computers, like most buildings, share a common basic architecture. The basic circuit for most digital computers was proposed in the late 1940s by J. von Neumann. A computer, like a building, is a system, i.e. a logical connection of basic blocks, each of which has a specific purpose. Often these larger blocks are called subsystems and are made up of smaller blocks that serve a specific purpose, which often include even smaller blocks and components.
A digital computer includes five main subsystems: a control device, an arithmetic-logical unit, memory subsystems, input-output and internal communications.
Memory.
There are two types of computer memory: main and external. The main memory is designed like a post office: it consists of microscopic cells, each of which has its own unique address, or number. An element of information is stored in memory with a certain address assigned to it. To find this information, the computer “looks” into the cell and copies its contents to its “command” point. The capacity of an individual memory cell is called a word. Typically, a word length for a personal computer is 16 binary digits, or bits. A length of 8 bits is called a byte. Typical large computers deal with words of 32 to 128 bits (4 to 16 bytes) in length, while minicomputers deal with words of 16 to 64 bits (2 to 8 bytes) in length. Microcomputers typically use words of length 8, 16, or 32 bits (1, 2, or 4 bytes, respectively).
External memory is usually located outside the central part of the computer. Since external memory is slower than the main one, it is used mainly for storing information that the computer does not urgently need. To use external memory, the computer's "command post" usually transfers the desired contents of a portion of the external memory to the main memory. Main memory is limited in capacity, so computer designers strive to store as much information as possible in external memory.
CPU.
The key subsystems of a computer are the control unit (CU) and the arithmetic-logical unit (ALU). Together they make up the central processing unit (CPU) - the “command post”. The CPU is where the computer manipulates data, stores a trace of its commands, and controls other subsystems. In most microcomputers, the CPU is located on a single microelectronic chip. In minicomputers, the control unit is often located on one chip, the ALU is on another, and the instructions that control both of these devices are on a third. In large computers, the CPU is spread across many chips. In all cases, the CPU takes up relatively little space.
The central processor deals directly with the program stored in main memory. A program is simply a list of instructions that tell the computer what to do. Most computer programs contain two types of information: instructions and data. The instructions are interpreted by the control unit, which controls everything that needs to be done, such as addition in the ALU. Commands are sent to the controller in the form of an operation code, so called because it tells the computer what to do next. Most computer problems are solved by manipulating data: moving words from one memory location to another, adding, subtracting, comparing and changing words.
The components of a typical CPU are shown in the figure. Typically, an ALU performs the following functions: addition, subtraction, logical operations, comparison, and bit manipulation. The ALU is connected through wires to a series of registers, which are sets of memory circuits that act as temporary storage devices while the CPU is operating. Typically, a computer has two sets of registers: one to use the CPU, and one to hold traces of the commands of the program involved. Among the CPU registers, we highlight first of all the adder, which is a device that directly serves the ALU. The most recent results of operations are usually found in the adder. Other registers include the program counter (which stores a trace of the addresses of instructions to be fetched from memory), the stack pointer (which stores a trace of the intermediate results of calculations), and various general-purpose registers. The controller deciphers the instructions retrieved from memory, generates and outputs the control signals needed to move data around the computer, and tells the ALU what to do next.
Other types of architecture.
Although most computers are of von Neumann architecture, other architectures are also used. There are two types of von Neumann CPUs, referred to as CISC (Complex Instruction Set Computers) and RISC (Simplified Instruction Set Computers). A traditional CPU is a CISC type that can execute a huge variety of commands; RISC has fewer instructions but is faster. A RISC processor is more suitable for tasks that involve multiple operations on relatively simple calculations, such as graphics-intensive applications; CISC processors are preferred in general purpose applications.
For both of these types of processors, the situation is approaching where the speed of calculations is limited by the need to perform everything on a single processor. Some supercomputers, such as the multiprocessor machine, solve this problem by using parallel arrays of Neumann processors. Multiprocessor machines are used where large amounts of similar data must be processed, such as weather forecasting and high-resolution graphics. A parallel machine distributes data among processors and performs calculations simultaneously. Another type of machine with parallel processors, a cluster or neurocomputer, uses very simple microprocessors. Each one acts like a neuron, responding to signals from several different inputs. A neurocomputer contains a highly interconnected network of such microprocessors. Neurocomputers can learn: when new data arrives, they adjust the responses of individual microprocessors and/or change the paths of interconnections. These computers are not programmed using the algorithms used in other digital computers; connections, response algorithms and learning laws are specified by the programmer.
Internal communications.
The computer must have a central communication channel connecting all the main subsystems. In many computers this channel is called a bus. Many mini- and microcomputer systems contain a corresponding general-purpose bus that can connect various specialized functions to the computer. A computer with such a bus can be upgraded gradually as requirements increase or technology changes.
Input and output.
The purpose of the input function in a computer is to convert external information (images, sounds, keystrokes, pointer positions, thermocouple voltages, etc.) into binary numbers.
The output function - the inverse process - converts binary numbers into visual images, printed characters, sounds, control voltages, etc. Essentially, anything that is measurable and can be converted into the electrical equivalent of binary numbers can be used by a computer. Whatever a computer is capable of calculating can, in turn, be converted into a form that can be understood by humans or other machines. One commonly used I/O pin contains two devices: an analog-to-digital converter and a digital-to-analog converter. The first converts voltages, such as those in an analog computer, into binary numbers; the other converts binary numbers into voltages.
COMPUTER HARDWARE
In the following, it is assumed that everything said applies to both large and personal computers. Differences will be specifically stated.
Electronic digital computers consist of two basic types of circuits: logic gates and flip-flop memory circuits. Of course, a computer contains other types of circuits, such as drives, buffers, and oscillators. But gates and flip-flops ( see below) perform key logical functions of a computer. The gate has no memory and generates the desired output only when the corresponding input signals are present.
Flip-flops are the key elements of memory circuits. The output voltage of the flip-flop changes from its original value to another when a certain input signal arrives, and remains unchanged until another signal arrives, which causes the flip-flop to return to its original state. The most familiar example of a trigger is an electrical light switch. Let's say the lights are off. Then, when you press the button, the switch closes and the light comes on. Press the button again - the switch opens and the light goes out. This is the equivalent of a single input flip-flop. (A flip-flop with two inputs can be represented by a dual switch.) The flip-flop position is "on". set by the “set” signal, position “off” – “reset” signal.
Computing began with the development of electronic computers; the first were machines using vacuum tubes (the first generation of computers). Tubes are faster and more reliable than relays. Tube computers predominated from about 1944 to 1958. The second generation of computers evolved within a few years of the invention of the transistor (1947). Transistors are smaller, more reliable and consume significantly less energy than vacuum tubes. The first transistor computers were not much faster than tube computers, but had other advantages.
The third generation of computers began with the introduction of a multi-transistor form, the integrated circuit. In an integrated circuit, the maximum possible number of circuit elements is placed on a piece of substrate (usually silicon). Every integrated circuit of the early 1960s contained four or five logic gates. In the early 1970s, the first large-scale integrated circuits (LSIs) appeared. In the 1980s, the emphasis was on very large-scale integrated circuits (VLSI) and ultra-high-speed integrated circuits. In the 1990s, Intel created the i860XP chip, a high-performance microprocessor containing 2.5 million transistors; this chip simultaneously processes 64 bits at a speed of 100 million operations per second. The number of components on a chip has doubled on average every year since 1966, and the pace continued until the end of the century.
The integrated circuit has many advantages over the discrete transistor: it is faster, more reliable, consumes less power and is much smaller. The Intel chip mentioned above is a rectangle measuring approximately 10 x 15 mm, and the connections on it are 0.8 microns wide. An electron beam is used to draw these exceptionally fine lines. Small element sizes also make it possible to increase the performance of integrated circuits. Vacuum tube computers had speeds of 50,000 operations per second. In the second and third generations of machines, circuits operated in the nanosecond range. Fourth-generation machines, also called supercomputers, perform tens or hundreds of millions of operations per second. In the Krey-2 machine, for example, the problem of speed is solved by giving it a cylindrical shape, which allows minimizing the length of the conductors connecting its elements.
The next step in attempts to increase the speed of computers is the creation of optical microelectronic circuits. Optical circuits, which transmit data in pulses of light, take advantage of the fact that light waves in glass fibers travel with less delay and distortion than electronic pulses in wires. The use of these methods will allow small computers to have the speed and capabilities of modern supercomputers.
CPU.
A typical computer's CPU consists of a large number of logic gates and flip-flops. The ACU uses many gates to select the type of processing that should be performed in the ALU, and also to send the resulting results to other parts of the computer. The registers we talked about above are mostly matrices of flip-flops. There are a number of trends emerging in CPU design and manufacturing. In large computers and many minicomputers, the CPU consists of a collection of chips, each of which performs a special function. In these machines, each of the main CPU blocks - ALU, control unit, microinstructions for control unit - can be located on one or more chips. (Microinstructions essentially tell the controller what wires and gates need to be connected to execute the instruction.) These CPUs are too complex to fit on a single chip. This approach also allows changes to be made to the computer's circuitry by replacing one or two chips rather than the entire CPU.
In some computers, the task being performed is divided among several CPUs. This technique is known as parallel processing. Some CPUs operate directly in terms of a programming language ( see below), rather than conventional architecture. Expect an increase in the variety of CPU designs and capabilities. A shift away from traditional architecture is also likely as processing volumes and speeds increase.
Perhaps the biggest leap in CPU design came with the introduction of Intel's 4044 microprocessor in 1971. This 4-bit microprocessor was a relatively slow chip with a limited instruction set, but it and its successors made pocket calculators and digital watches possible and led to the development of the microcomputer. In 1974, 8-bit microprocessors appeared, processing 8 bits of information simultaneously.
As mentioned earlier, the microprocessor (or other CPU) receives information in the form of “words.” For example, the computer memory, according to commands from the control unit, supplies 8 bits to the adder at once. Then the control unit adds, for example, the number 00101101 to the bits in the adder (all at once again). The adder now contains a new set of 8 bits. Next, the control unit transfers these 8 bits to memory, all at once. In each of these steps, 8 bits are processed or moved simultaneously, but the individual actions - entering them, adding them, copying the result - are performed sequentially. Basically, the larger the word size available for the CPU to process, the more information it can "swallow" at once and the faster it completes its tasks.
Eight-bit microprocessors gave birth to microcomputers, sophisticated computer terminals, and a number of “smart” devices; Advances in computing technology continue. In the 1990s, there were hundreds of millions of 8- and 16-bit microprocessors, and most new personal computers and workstations used 32-bit microprocessors that performed millions of operations per second. In 1999, Intel released a high-performance Pentium III microprocessor with a clock frequency of 500 MHz, integrated cache memory of up to 2 MB and enhanced capabilities in areas such as speech recognition and three-dimensional graphics.
One of the logical consequences of microelectronic technology was to develop the entire computer, including memory, on a chip. Of course, for such small computers the memory is quite limited, but it is sufficient for the development of devices such as relay regulators for automatic ignition and fuel systems of cars and microwave ovens, as well as full-fledged “pocket” computers.
Memory devices.
Main memory.
The main memory device for second-generation computers and many large third-generation computers was the magnetic core - a tiny ring of magnetic material the size of a bead. With the help of thin wires stitching rings in vertical and horizontal directions, a mesh is knitted from these cores inside the computer. Each core stores a magnetic charge. The direction of magnetic flux determines the state of 1 or 0. Core memory was invented in 1948 by E. Wang and was widely used in the 1950s and 1960s.
The memory device on the cores is non-volatile memory, i.e. it retains its contents even when the power goes out. The cores performed the functions of tube triggers that appeared earlier and led to the appearance of the term “random access memory”. On-core memory was later replaced by microelectronic devices, but is still used in military equipment, spacecraft, and other specialized applications.
An important addition to the microprocessor is integrated circuit memory. There are two main classes of this memory: random access memory (RAM) and read only memory (ROM).
RAM is fast: the microprocessor can access it in 10–20 ns. Typical commercial RAM modules store up to 256 MB (1 MB equals 1,048,576 bytes). RAM is reliable and lasts for years, performing billions of operations. RAMs only remember what you last told them; everything else is erased. RAM consumes fairly little power when compared to other integrated circuits of approximately the same size and packaging density. Some RAM uses so little power that a small battery is enough to activate or at least maintain its memory after the main power source is turned off. These RAMs are often used in small laptop computers and calculators.
When the power is turned off, the RAM loses its memory. The ROM remembers almost forever. ROMs are especially useful for tasks that require the same set of instructions to be repeated over and over again. ROMs usually work slower than RAM, but their memory is permanent and noise-resistant. In addition, the loss in ROM response speed is compensated by packaging density.
A characteristic of RAM and ROM called random access refers to the ability of a microprocessor or other CPU to access any element of memory at any time. For example, if a telephone number is stored somewhere in RAM or ROM and the CPU (through its program) knows where that number is, then the CPU can dial it almost instantly. It is only important that you know where it is.
Not all ROMs have absolutely permanent memory. Some ROM-like devices have, so to speak, semi-permanent memory, i.e. they remember (even when the power is turned off) what they were told until they are erased and rewritten. Erasing is accomplished by exposing the chip to high-intensity ultraviolet rays (such as EPROM) or other means, as in some modern erase-write memory chips.
External memory.
External, or peripheral, memory includes magnetic tapes, magnetic disks, and magnetic domain memory. External memory is cheaper than internal memory, which is usually created on the basis of semiconductors. Additionally, most external memory devices can be transferred from one computer to another. Their main drawback is that they work slower than internal memory devices.
Many people are familiar with magnetic tapes as external memory devices from audio and video cassette tapes. Both of them store analog data, i.e. signals that change continuously - for example, from the pianissimo of a violin to the major sound of a rock band's brass instrument. To use these media in computers, it is necessary to convert analog signals into digital form, i.e. into signals corresponding to the binary digits 0 and 1. This is a relatively cheap and rather slow medium. However, high-power computers often use high-speed multi-track magnetic tapes to store large amounts of data. These tapes are convenient for backing up all information from the disks of computer systems ( see below).
Tape cartridges are similar in appearance to audio cassettes, but are designed for digital recording. The recording density in them is higher than that of audio cassettes, and the tapes are subject to special testing. They are used when creating backups for hard drive systems. Digital audio tapes are also used as a backup medium. However, a cassette smaller than an audio cassette can store up to a billion bytes of data. All types of tape storage devices have one main drawback - sequential mode of operation, i.e. the feed must scroll to the desired element, which takes a lot of time. The requirement to save time forces the user to turn to another, more popular means of storing information for small computers - a floppy disk, or floppy disk.
A flexible magnetic disk is a compromise solution between magnetic tape and a gramophone record. It is a small, thin and flexible plastic disc that has a magnetic coating on one or both sides. The coated disk is enclosed in a protective envelope or shell that has openings for access by the read/write head and drive motor.
Floppy disks are “played” in the same way as a gramophone record, but using a magnetic recording head rather than a stylus. Like magnetic tape, a floppy disk can form a permanent record of a program or data; Because it is erasable, its contents may be changed.
A floppy disk, unlike magnetic tape, is a random access device. The information recorded on the disk is located in concentric circles (tracks) on its surface. One or two tracks are usually used to store the table of contents. To find a specific record on a disk, the computer instructs the magnetic head to move to the table of contents track and find the coordinates of the location of the desired information; in this case, the disk rotates under the magnetic head. Once the desired entry is found in the table of contents, the computer orders the magnetic head to move to the appropriate location on the disk. The same principles apply when recording information. To change information on a magnetic tape, you need to read the entire tape, paste the changes, and overwrite the changed version. The floppy disk principle allows you to correct a specific segment of records without affecting the rest of the surface. This is why recording on a disc can be done in parts, each of which is inserted into any suitable place. The only additional requirement is that the table of contents on the disk be updated to reflect changes made on that disk.
The industry produces flexible disks mainly in sizes 3.5 inches (89 mm). A typical floppy disk can store up to 1.5 million characters (bytes), which is equivalent to 900 pages of double-spaced typescript. There are also disks with larger information capacity. Almost all personal computers are equipped with floppy drives.
A hard drive is similar to a floppy drive, but is made of durable and rigid materials. It can spin faster and hold more information. A typical hard disk drive for a personal computer is almost the same size as a floppy disk drive, but the capacity of a modern hard disk reaches 25–50 GB, i.e. thousands of times more than flexible. In addition, hard drives communicate with your computer much faster than floppy disks. A search that takes up to several seconds on a floppy disk takes only hundredths of a second on a hard drive. The hard drive in most computers serves as an external storage device for current recordings and application software.
Usually the hard drive is enclosed in a durable, sealed case. If such a drive fails, the computer, which has no backup memory, becomes useless. Some hard drives, like floppy drives, can be removed from the drive. Hard drives are more expensive than floppy disks, but their cost per unit of capacity is constantly decreasing.
An optical disc is similar to both a magnetic disc and a gramophone record. There are CD-ROM discs, write-once-read-many discs, and erasable discs. CDs and write-once discs are used to store large amounts of information that cannot be changed. The latter are filled in only once, and the entered information cannot be erased. Erasable optical discs can be used similarly to hard drives. Optical discs range in size from the size of a video disc to the 133 mm or smaller diameters found in audio CDs.
An optical disc, like a gramophone record, stores information on a spiral track. As in the case of a magnetic disk, the read head of an optical player moves along a fixed guide radially back and forth, rather than on a lever rotating about a certain center, as in the case of a record. A laser beam is used to record and read information.
An optical CD stores information in the form of small surface indentations corresponding to binary numbers. Variations in the intensity of the laser beam reflected from these depressions are detected by a photocell, which converts them into electrical signals. Erasable optical discs have a coating that responds to the magnetic field from the drive's write head by changing the optical polarization. These changes can then be turned into electrical signals by the read head. Information recorded on a magneto-optical disk is erased by the combined action of a magnetic field and a laser beam.
A CD-ROM with a diameter of 120 mm can store over 300,000 pages of printed text, or 650 MB of information. Commercial CD-ROMs are used to host numerous and varied reference materials, computer graphics clips, animations, and combinations of text, sound, and images. They are becoming indispensable in multimedia systems. Magneto-optical disks have the same dimensions as common floppy disks (89 and 133 mm).
Memory technology is constantly improving, which leads to increased speed and reliability and reduced cost, and the user has a choice that practically satisfies the given computing task.
I/O devices.
The computer must be able to communicate with the outside world. In addition to the external memory devices discussed above, the computer is equipped with connections to the operator, telecommunication lines, sensors, actuators and other machines.
Human-computer interface.
Communication with a computer is not yet similar to conversation with a person. Rather, it resembles communicating with a typewriter. This situation is partly the result of shortcomings in the hardware, but in large part it is due to the inadequacy of the software - it is not clear, for example, how people think, and even less is it known how to program a computer to simulate thinking even in simple cases.
The most common human-machine interface devices for a computer are a display, similar to a television screen, and a keyboard, similar to a typewriter keyboard. The display is a cathode ray tube (CRT) terminal. Typically, personal computer displays have significantly higher resolution than home television screens. For example, a VGA display (an abbreviation for video graphics adapter) shows 640-480 dots on the screen. During the 1980s, displays and associated controller boards on computers were largely character-oriented: the display controller included a ROM containing dot patterns for alphabetic and graphic characters (up to 255). The computer told the display controller where on the screen to place each character, as well as which character (if any) to use in which location. As computer memory has become cheaper, the use of raster displays has expanded, in which the controller calculates the brightness and color of each point on the screen. Raster displays are required in graphical user interfaces (GUIs, see below). Most displays in the early 1980s were monochrome; by the mid-1990s they were replaced by full color.
An important addition to the display is a printer. It provides a long-lasting copy of the computer's output. Computer printers range from low-resolution printers to near-print-quality printers. Typical dot matrix printers have a resolution in the range of 56–141 dots/cm and can take up to 10 seconds to print pages of text. Laser and LED printers consist of mechanisms similar to those used in phototypesetting machines. The movement of a laser beam (or an array of LEDs) forms a linear image on a rotating light-sensitive drum, which transfers this image through an electrostatic charge and toner to a sheet of paper. The cheapest desktop laser and LED printers provide 108 dots/cm resolution and print up to 14 pages of text per minute. Graphics usually take longer to print, regardless of the printer type. Printers for large computers allow you to print huge volumes of paper in a short time.
Other human-computer interface tools include a mouse for moving positional information on a CRT display or television screen and pointers for selecting specific locations on a display screen or drawing board. Some CRT displays allow you to use your finger as such a pointer.
Interfaces for telecommunications.
A personal computer connected to a telecommunications system can communicate with other computers connected to that system. The device that performs this function through a regular telephone line is called a modem (short for the full name "modulator-demodulator"). There are two types of modems. One is an external unit that connects to the telephone line and computer. The other takes the form of a board installed inside the computer. (All commercial modems meet the requirements to prohibit the use of unauthorized communications devices.) The advantage of such a modem is that the computer is programmed to automatically dial a telephone number. Modems have transmission speeds from 120 to 56 thousand characters per second. Modem speeds, signal transmission rates and data compression methods are regulated by international standards. Thus, it becomes possible to exchange information relatively easily and quickly between many geographical locations around the globe. Since the late 1970s, a number of other communications systems have emerged, designed specifically for use with all types of computers. These systems are called local area networks, or LANs. They form the basic technology of various automation schemes for institutional work. Automation of such work is a major area of computer applications; it focuses on the use of computers (especially microcomputers) linked to communication systems to facilitate the flow of information.
Sensor–actuator interfaces.
In the early days, the main use of computers was to control machine tools. Minicomputers connected to large lathes, milling machines and other manufacturing equipment can monitor and adjust machine operations to consistently produce the required parts. Such a computer is equipped with sensors that provide it with information about the position of the working elements of the machine, for example a turret with a cutting tool, and the workpiece being processed. The computer compares the sensor readings with its preprogrammed instructions and issues commands to the actuators to move the working elements of the machine so as to ensure compliance with the design data. Computers are often used to replace humans in hazardous tasks, such as handling radioactive materials. ROBOT.
Personal computers can manage many household activities, such as energy consumption, fire protection systems, heating and security systems, provided they are equipped with the right sensors (temperature and lighting, humidity, burglar alarms, etc.). The disadvantage of such systems is their high cost. Until integrated circuits are integrated into most household appliances and devices, the use of personal computers in collecting sensor information and controlling related household devices will remain unprofitable.
Major automobile manufacturers have begun to use integrated circuits and microprocessors in automotive control systems—primarily emission control and fuel economy systems. Many different sensors are being developed for the automotive industry; Over time, similar devices will be available for household appliances.
Next generation computers.
The advent of highly parallel and neural computers heralded the first results of a new technological revolution. One of its key points is the concept of knowledge processing. Knowledge processing involves the development of computer "thinking" similar to the intellectual activity of an expert. The typical next generation machine will be a true electronics expert in a specific field. The user will communicate with such computers in natural language, rather than through the stylized codes used by today's systems. The United States and Japan occupy the leading positions in the development of next-generation computers.
COMPUTER SOFTWARE
Software is a collection of computer instructions. It covers programs, subroutines (program sections) and data. Thus, the software tells the computer what to do, how, when, in what order, and how often. Often software is simply called a program.
Computer programs consist of lists of commands that cause the computer to do a desired job. The computer must receive comprehensive, specific commands. Often computer programs take the form of transcripts.
Programming concepts.
There are two large categories of programs: system and application. System programs deal with the interactions between the various components of a computer. For example, the Windows operating system is a program or set of programs that tells the CPU how to transfer data and instructions within the processor, between the computer's internal memory, disk storage, and input/output devices such as CRT terminals or monitors, printers, modems, sensors, etc. It performs service functions, such as tracking where application programs are stored on the floppy disk with which the computer communicates. The best system programs are those that allow the computer to do its job without requiring the operator to be familiar with it.
An application program is a set of commands for solving external problems other than the main internal workings of the computer. An example of an application program is a word processing or database management program.
Languages.
The only language that a computer understands directly is made up of zeros and ones (on and off, yes and no, true and false), necessarily repeated and ordered. For example, for Intel 80X86 series microprocessors (where X is any number from 1 to 5), the following statement is acceptable: 1000011000000111. This two-byte bit sequence means the command “Add the number 7 to what is in the adder.” An adder is a register in the CPU that stores the most recent results of what has been processed. The given sequence of bits, while clear to the CPU, is featureless and meaningless to the average person. Therefore, languages were invented that translate statements that humans understand into bits and back again. The next step in the abstraction layer is the creation of assembly language.
In the assembly language of Intel 80X86 microprocessors, the above 16-bit command looks like this: ADD 07. This is already more understandable.
Assembly language programs provide the most compact form of commands to achieve the desired goal. However, the program text turns out to be very long. High-level languages such as C, Pascal, BASIC, Cobol, Fortran, Java and the like use more memory than assembly language, but are much easier to work with. As the cost of memory began to decline and the cost of a programmer to rise in the 1970s and 1980s, high-level languages became dominant.
C is a powerful language developed by Bell Telephone Labs. (USA), which allows the programmer to work with the specification inherent in assembly language. It also provides a high level of abstraction. In the early 1990s, C became the most popular commercial application language for personal computers. BASIC's initial major advantage was that it was relatively easy to learn; Since then it has become quite a powerful language. Pascal, originally created to teach structured programming techniques, is also very popular among personal computer users. A variant of Pascal is Modula-2; both languages were developed by N. Wirth. There are a number of other high-level languages, each of which is best suited for a particular type of task. COBOL was intended primarily for business; It is especially good for processing large files such as inventory and payroll records. Fortran is the primary computer language of scientists and engineers; he specializes in mathematical formulas and complex calculations. The development of the Ada language was funded by the US Department of Defense. Lisp and Prolog are the main languages of artificial intelligence research. Logo spun off from Lisp and serves to develop methods of teaching with the help of computers.
All high-level languages, including those mentioned above, are procedural languages, i.e. they issue detailed step-by-step commands to the computer. Another group of high-level languages is object-oriented. Object-oriented programming (OOP) focuses on breaking down common processes into modules and organizing the latter into units that can be reused for a variety of functions. Each program object has a precisely defined behavior and set of characteristics. Each object reacts to messages from other objects in a predetermined way. The details of such a reaction are included in the object code and are “invisible” to other objects. For example, to draw a frame on a display screen in a procedural language, the programmer must write commands that detail the drawing process from the starting point to each subsequent point, indicating which points on the screen should be highlighted. In an object-oriented language, the programmer simply writes a command that draws a frame of a given size in a specific location. Examples of OOP languages include Smalltalk, Ector, C++ and versions of Turbo Pascal.
Computer programming is hard work. For this reason, menu programming, or user programming, is popular among application programmers. An inexperienced programmer may choose a language such as BASIC (the language preferred by non-professional programmers) for the detailed structure of the program, but the parts of the program that the operator sees will appear in a natural language such as English or Russian. When executing a program, the operator selects the desired option from the menu. The selected alternative may cause the display of another set of alternatives, one of which must be selected, etc.
With the increasing popularity of personal computers, a significant number of more traditional application programs must be written in a menu-like or user-oriented format. The emphasis in the software will be on creating the clearest and most friendly human-machine interface possible. One particular aspect of this study deserves special attention.
Free software.
The expansion of the production and use of personal computers significantly accelerated the development of the so-called. firmware software. In this case, the user can, through computer controls, interact with a display depicting some kind of logical or visual structure. The user can enter the necessary information from the keyboard at any point on the display, and then move on to the next point. This structure can be used multiple times (if necessary, each time with different data). To work in such a program, the user is not required to know anything about programming. Many spreadsheet and database programs have these non-software characteristics. The primary means of querying large mainframe databases is based on SQL (Structured Query Language), in which the user queries information from the database using a syntax much like regular English. It has become popular to link SQL to personal computer databases.
Graphical user interfaces (GUIs).
Computer displays have evolved from character-based images to extensive raster graphics. This development has made it easier to develop programs - especially operating systems, including graphics and a variety of visual techniques. Many programs can be displayed on the screen and application programs can be executed simultaneously. The Macintosh series of computers produced by Apple (USA) marked the beginning of the widespread use of GUIs for personal computers. Windows programs (Microsoft, USA), OS/2 Presentation Manager (IBM, USA), New Wave (Hewlett-Packard, USA) and most software for workstation displays use GUI and OOP.
APPLICATION OF COMPUTERS
Wherever there is a need to quickly process large amounts of information or perform routine, repetitive tasks, the need for computers arises.
Education and information dissemination.
Computers are becoming extremely useful tools in education. In some applications, such as standard teaching, they can serve as excellent teaching aids. They are also ideal for self-study, when the goals and content of the course are clearly defined. Well-programmed computers may be better than the average teacher at solving these problems. Modern media (television and print) are also based on computer technology.
Business.
The first steps of computers in business relate to banking and insurance, where huge amounts of data have to be processed every day. When banks introduced magnetic checks in the 1950s, it became possible to process them on computers. Computers became available to tellers at banks and other financial institutions, and with the increasing use of automated teller machines, they began to replace tellers themselves. Credit and debit cards are used to carry out automatic and fast banking transactions via computer. The implementation of the “bank here and now” concept depends on the spread of electronic funds transfer technology based on the use of computers. The next logical step is to conduct banking transactions from users' home computers and terminals.
In the field of office automation, computers linked by telecommunications are applicable to tasks such as processing email, text, and documents. Using an office or desktop computer, you can write a note, do calculations, draw graphs, check spelling, and automatically send the results by email.
Computers quickly gained a leading position in manufacturing. With the advent of numerically controlled machines and industrial robots, which ensured the automation of specific production processes, computers and telecommunication networks made it possible to expand the creation of the so-called. complex automated production. In such production facilities, all technological processes, including processing centers, conveyors and conveyors, are controlled and regulated by computer networks. The telephone network is controlled almost entirely by computers. In the coming years, it will completely switch from analog signal transmission to digital. As a result, it will be possible to send a variety of information directly to your home, including live images.
Computer in the house.
While many home computers are used primarily for entertainment and education, they are also increasingly used for economic tasks, from managing money and investments to running a home-based business. Nowadays there is no longer any need to know anything about a computer in order to work successfully on it. Electronic bulletin boards and commercial information systems provide hundreds of thousands of users with information on virtually any topic. There is an increasing trend towards creating a variety of “smart” devices. In addition to microwave ovens, many of which “talk” to the user, there are environmental control and conditioning devices, programmable recorders and radios, home security systems and smart phones; they all run on microprocessors.
Literature:
Nagao M., Katoyama T., Uemura S. Structures and Databases. M., 1986
Poole L. Working on a personal computer. M., 1986
Traister R. IBM personal computer. M., 1986
Deitel G. Introduction to operating systems. M., 1987
Zhigarev A.N. etc. Basics of computer literacy. L., 1987
Computers: Reference Guide. M., 1987
Lord N. et al. Computing machines of the future. M., 1987
Michie D., Johnston R. The computer is the creator. M., 1987
Rybakov M.A. Anatomy of a personal computer. M., 1990
Hasemir R., Fanenstich K. Word Processor 6.0 for Windows. M., 1996
Figurnov V.E. IBM PC for user. M., 1997
Thematic resources
Computer reference books and encyclopedias
- Megaencyclopedia of Cyril and Methodius
http://www.megabook.ru
Ten encyclopedias (universal, automotive, health, cinema, cooking, music, etc.). Explanatory dictionary of the Russian language, English-Russian and Russian-English dictionaries, economic dictionary. - World of encyclopedias
http://www.encyclopedia.ru
The site reveals to you the world of encyclopedias: basic concepts, the history of encyclopedias, their modern development. Most of the materials are devoted to Russian-language encyclopedic publications - encyclopedias, encyclopedic dictionaries, reference books. The site materials try to cover all encyclopedic publications in Russian - Continuing Education
http://erudit.narod.ru
Selected links to the most significant educational Internet resources are presented. The information provided may be useful to high school students, students, engineers and scientists. At your service are electronic libraries, dictionaries and reference books, distance learning resources, abstracts and drawings, as well as many other useful links. - "Pedagogical encyclopedic dictionary"
http://dictionary.fio.ru
A complete electronic version of the dictionary, published in 2002, edited by the scientific publishing house "Big Russian Encyclopedia". The dictionary contains about 3,000 detailed articles that provide the teacher with modern and interesting information in the field of educational theory. The dictionary most fully reflects all changes in the science of domestic education, in particular, business education and distance learning. A significant place in it is occupied by data on methods, technologies and techniques of education. In fact, in addition to background information, the reader can find theory and examples of practical importance for a teacher or researcher. - Virtual encyclopedic and reference publications
http://www.openweb.ru/stepanov/library/referen.htm
Annotated links to encyclopedias, dictionaries, translators (Britannica, Microsoft Encarta, Cyril & Methodius, Prompt, etc.). - Rubricon
http://www.rubricon.com
The server provides access to more than three dozen of the most famous domestic encyclopedias, dictionaries and reference books. Among them are the complete edition of the Great Soviet Encyclopedia (1969-1979), personal articles from the Encyclopedic Dictionary of Brockhaus and Efron (1890-1906), Illustrated Encyclopedic Dictionary, Small Medical Encyclopedia, Encyclopedic Dictionaries "History of the Fatherland" and "World History", "Explanatory Dictionary" living Great Russian language" by Vladimir Dahl and others. All sources are presented in full text with a full list of illustrations and bibliography. Internal links between articles have been converted into hypertext links, which allows you to easily move from article to article, getting acquainted with all aspects of the issues being studied. Rubricon is distinguished by high request processing speed and a comfortable user interface. To date, 14 publications are paid sources, and their number is likely to gradually increase. However, the cost of access to all paid publications is only 1 dollar - Encyclopedia "Around the World"
http://www.krugosvet.ru
It is an expanded and corrected translation into Russian of Collier's Encyclopedia, which was published in the USA from 1952 to 1998. For this reason, the content and style of presenting material in Krugosvet clearly gravitate towards the American original. consist in extending the chronology of articles related to modern times and adding a significant number of personal articles about Russian figures, including those living today. In addition to the texts, illustrations are included: portraits, maps, views of cities and historical monuments. Search is possible both by keyword and. by branches of knowledge.
At the end of each article of "Around the World" there is a function "Search on the Internet." In this case, a request that exactly repeats the name of the encyclopedic article is redirected to the Aport search engine. - Encyclopedia Britannica
http://www.britannica.com
Online version of the world's most authoritative encyclopedia. Contains more than 72 thousand articles on all branches of knowledge. Updated annually. The search result includes not only texts from the encyclopedia, but also links to Internet resources, as well as selected journal publications. Articles are provided with hyperlinks to other sections of the encyclopedia. In many cases, illustrations, tables, and video files are presented. Britannica is currently a completely paid resource. If you need to use its resources, you can sign up for a free “trial access” lasting 72 hours. - Microsoft Encarta Encyclopedia
http://encarta.msn.com/reference
A free version of the well-known universal encyclopedia, published annually by Microsoft on CD-ROM. Contains more than 18 thousand articles and 2 thousand illustrations (photos, maps). You can search using keywords to clarify your area of knowledge. The texts of the articles include hypertext links to other sections of the encyclopedia. Some articles and illustrations are available only to subscribers. - CIA Fact Book
http://www.odci.gov/cia/publications/factbook
Contains detailed factual and statistical information about all countries of the world and major international organizations. Information is included on the geographical location, size and composition of the population, political activity and the degree of development of the main sectors of the country's economy. An indispensable source for obtaining reliable statistical data on the economic, military, social and cultural development of any country in the world. The illustrative material is represented by a political map and flag of the country. Information is updated annually. - English-Russian/Russian-English dictionary on the Rambler server
http://www.rambler.ru/dict
It is also based on the New Great English-Russian Dictionary, published in 1993-94, edited by Yu. D. Apresyan and E. M. Mednikova, containing about 250,000 words. The result of the translation is made in a different form - in particular, comments on the use of terms are collapsed and shown to the user only at his request. Due to this, it is easier to navigate the results than the results produced by MultiLex. The same server contains German-Russian and Russian-German dictionaries. - Online translator of the company "Promt"
http://www.translate.ru/Rus
The server contains a whole range of interactive dictionaries that provide mutual translation from/to English, German and French, as well as one-way translation from Italian and Spanish. The most valuable characteristic of Promt dictionaries is their ability to translate entire phrases, complete sentences and even entire documents. The quality of the translation is quite high. A special feature also allows you to translate entire web pages and emails. - Merriam-Webster Dictionary
http://www.m-w.com
Full-featured Webster's dictionary in electronic form. It not only searches for interpretations of terms, but also makes it possible to listen to both the main word and its derivatives. - Roger's Thesaurus
http://www.thesaurus.com
Well-known source in electronic form. In response to the entered English term, it produces a list of words related to it in meaning. A serious resource for professional linguists and translators. - Biographical database on the Biography server
http://www.biography.com
Contains brief information about more than 25 thousand people, from heroes of the Ancient World to modern figures from different countries. Searching is possible either by entering a surname in the search bar or by sequentially viewing an alphabetical list. A standard curriculum vitae contains dates of life and a brief history of the individual. - Aviation from A to Z
http://www.cofe.ru/Avia
A very informative encyclopedia of world aviation in Russian, including brief characteristics of aircraft and their photographs. The search is carried out by the name of a specific aircraft or helicopter, types of aircraft, and also by entering keywords.
Online reference books and encyclopedias
In some cases, it may be necessary to find not just a document containing a keyword, but the interpretation of a certain word. When you search for an unfamiliar term using a search engine, you risk getting a whole series of articles in which this term is used, and at the same time you will not know what it really means.
In some cases, you can use a search with keywords like “what is (unknown term)”, “(unknown term) is” or “(unknown term) is”, etc.
However, unless it is a new term, it is preferable to start such a search in an online encyclopedia.
Universal
One of the largest online encyclopedias is the Yandex. Encyclopedia resource (
http://encycl.yandex.ru/) - this project contains 14 encyclopedias, including articles from the Great Soviet Encyclopedia and the Brockhaus and Efron Encyclopedia. The largest ones include the Encyclopedia of Cyril and Methodius, which can be found at www.km.ru.
· Universal encyclopedias:
Brockhaus online, The world around us, Universal Encyclopedia of Cyril and Methodius, All-in-one: Encyclopedic reference book. Specialized: Great Russian Legal Encyclopedia, Medical and Biological Encyclopedia, Peoples and Religions of the World, Theater Encyclopedia, Economic Dictionary (Cyril and Methodius), Encyclopedia of Religions,
· Regional:
Americana. English-Russian linguistic and cultural dictionary, Bashkortostan: Brief encyclopedia, Odessica - encyclopedia about Odessa, Omsk region: Encyclopedic reference, Pskov encyclopedic dictionary, Traditional culture of the peoples of the European north-east of Russia, Encyclopedia of the Ivanovo region, Japan from A to Z: (Popular encyclopedia)
· Special:
Aviation from A to Z: Encyclopedia of World Aviation, Automotive Encyclopedia of Cyril and Methodius, Palaces of St. Petersburg, Internet. Your way out, Culinary Encyclopedia of Cyril and Methodius, Komi Mythology (Ural Mythology. Vol. 1), Extelopedia of Fantasy and Science Fiction, Encyclopedic Dictionary of Economic Terms, Encyclopedia of Arms of Cyril and Methodius, Encyclopedia of Pets of Cyril and Methodius, Encyclopedia of Health of Cyril and Methodius, Encyclopedia of Cinema of Cyril and Methodius, Encyclopedia of Moscow University (1755-1917), Encyclopedia of Vegetables, Encyclopedia of the Personal Computer of Cyril and Methodius, Encyclopedia of Rock, Jazz and Pop Music of Cyril and Methodius, Encyclopedia of the Third Reich, Encyclopedia of Fiction (Yu. Vitkovskaya), Encyclopedia fiction (Vl. Gakov), Encyclopedia of miracles, riddles and secrets, Encyclopedia of Cyril and Methodius etiquette, This day in history, GraphInfo - an encyclopedic dictionary on computer graphics, multimedia and CAD, World Wide Coins-Encyclopedia: 20th century on world coins.
· Personal:
Large Russian Biographical Dictionary, Orenburg Pushkin Encyclopedia, Orenburg Tolstoy Encyclopedia, Orenburg Shevchenko Encyclopedia
· Universal encyclopedias: Great Soviet Encyclopedia, Illustrated Dictionary, Russian Encyclopedia. Dictionary, Brockhaus and Efron “Rubricon”
· Dictionaries: New Dictionary of the Russian Language, Dahl Explanatory Dictionary, American English, Medicine and Health, Minor Medical, First Medical Aid, Dictionary of Medical Terms
· History: “World History”, “History of the Fatherland”, America - Russia, Encyclopedia of Ships
· Biographies: Biographical Dictionary, Political figures. 1917
· Russia: “Constitution of the Russian Federation”, “Moscow”, “St. Petersburg”, “Cities of Russia” “Geography of Russia”
· Countries, peoples, religions: “Peoples and Religions of the World”, Biblical Encyclopedia “Latin America”, “Americana”, “Australia and New Zealand”, “Great Britain”
· Art: Popular fiction, “Great Masters”, Rock Encyclopedia “Cinema”
· Economics: Information technology, Mutual investment funds, Largest banks, “Enterprise economics”, “Finance and debts”
· Statistics: Countries of the World 2000, Countries and Regions 2000, OECD Countries 2000
· Agriculture: Agriculture, Veterinary, Miscellaneous, “Animals in the House”
· OUTLOOK
· CALENDAR
· WORLD FLAGS
Brockhaus on-line
The basis of the encyclopedia was the “Small Encyclopedic Dictionary of Brockhaus and Efron” St. Petersburg 1907. The dictionary also uses pre-revolutionary dictionaries of foreign words by Pavlenkov, Mikhelson, and “Starchevsky’s Dictionary”. Contains more than 46,000 articles.
Big Encyclopedic Dictionary
Cyril and Methodius
Multiportal: Knowledge about everything. One of the sections of the site is a megaencyclopedia. Contains 130,000 articles, 30,000 illustrations, more than 1,400 tables and much more. You can also search by industry sections of the encyclopedia.
Information Please
The Information Please project provides the ability to select reference resources by topic.
Britannica Online
Encyclopedia Britannica. A 30-day free trial is provided. Without registration, it is possible to search, the result is several sentences from the beginning of the article with the searched word.
Microsoft Encarta Encyclopedia
A free version of the well-known universal encyclopedia, published annually by Microsoft on CD-ROM. Contains more than 16 thousand articles and 2 thousand illustrations (photos, maps). You can search using keywords to clarify your area of knowledge. The texts of the articles include hypertext links to other sections of the encyclopedia.
Encyclopedia.com
Presented by Columbia Electronic Encyclopedia, 3rd ed., contains 14 thousand articles
Online dictionaries and encyclopedias
Modern Encyclopedia, Dahl's Explanatory Dictionary, Ozhegov's Explanatory Dictionary, Ushakov's Explanatory Dictionary, Brockhaus and Efron Encyclopedia, Muller's English-Russian Dictionary, Large Encyclopedic Dictionary, Financial Dictionary, Economic Dictionary, English-Russian Dictionary of Financial Terms, Dictionary of Depository Terms, Historical Dictionary, 1000 biographies, Encyclopedist.
Edic - Encyclopedic dictionaries
· Dictionaries: Big Encyclopedic, Historical, Myths of the Peoples of the World
· Encyclopedias on Mnogo.ru: Musical Encyclopedia, Encyclopedia of Animals, Encyclopedia of Plants, Encyclopedia of Fashion, Culinary Encyclopedia, Catalog of Coins of the 20th Century, Encyclopedia “People on Coins”, Numismatic Dictionary, Dictionary of Economics
Universal explanatory dictionaries. Dictionaries of abbreviations
Ozhegov's explanatory dictionary of the Russian language
Russian dictionaries
The website presents a joint project of the Russian Language Institute. V.V. Vinogradov of the Russian Academy of Sciences and the publishing house "Azbukovnik".
· Explanatory dictionary of the Russian language by S. I. Ozhegov and N. Yu. Shvedova
· Russian spelling dictionary
· Popular dictionary of foreign words
· Dictionary of foreign words
· Russian semantic dictionary
· Dictionary of Pushkin's language
· Dictionary of Russian synonyms and similar expressions
· Dictionary of Russian argot
· Dictionary of Russian personal names
Oxford Reference Online
Access to more than 100 different dictionaries across a full range of disciplines.
WWW Webster Dictionary
Full-featured Webster's dictionary in electronic form.
Roger's Thesaurus
Well-known source in electronic form. In response to the entered English term, it produces a list of words related to it in meaning.
Dictionaries for translation
Internet translators of the PROMT company
English-Russian and Russian-English online translator
German-Russian and French-Russian online translator
Russian-German and Russian-French online translator
The English version of the site contains an English-French, German-French, French-English and French-German online translator
.
English-Russian Dictionary MultiLex™
English-Russian/Russian-English dictionary
Electronic translator. In response to the entered term, it returns not only its translation in another language, but also the most common expressions using this word.
French-English Dictionary
ARTFL Project - English-French and French-English dictionary.
OneLook Dictionaries
Its database has indexed more than 2,800,000 words from 585 different dictionaries operating on the network. The answer to the request is presented in the form of a list of links to dictionaries (both explanatory and multilingual), which contain the searched word.
Biographical reference books
Russian who's who
Biography Find
Biographical database on the Biography company server. Contains brief information about more than 20 thousand people, from heroes of the Ancient world to modern figures from different countries.
Biographical Dictionary
It contains information about more than 25 thousand inhabitants of the Earth who left their mark in various areas of life, from the Ancient World to the present. You can search by name, keywords and dates. There is an in-depth request form.
International Biographical Center (IBC)
Who's Who Online
WIC - Biography Index
Biographies of women
Search for reference books, dictionaries, encyclopedias
List.ru: Information
AU!: Help Desk
Sections of the Russian Internet catalog @Rus (AU!):
Dictionaries
Directories
Yahoo!: Reference
Yahoo Internet resource catalog sections:
Dictionaries Encyclopedia
The world of encyclopedias. Encyclopedias on the Internet
Dictionary.com
Search for dictionaries by thematic sections.
Encyclopedias, dictionaries
Collection of links on the server "Electronic and traditional dictionaries" (ETS)
www.study.ru
The site presents more than 100 dictionaries of various fields.
Dictionaries
A collection of links to various dictionaries (for translation, thematic, explanatory).
Encyclopedias, dictionaries, reference books
Encyclopedia - Britannica Online Encyclopedia
Encyclopedia Britannica. You can search through encyclopedia articles.
URL: http://www.britannica.com/
Great Soviet Encyclopedia
Electronic version of the Great Soviet Encyclopedia. Convenient search by alphabet and words.
URL: http://www.oval.ru/encycl.shtml
Large encyclopedic dictionary
About 90,000 articles from all spheres of life and society. Search only by the title of a dictionary entry.
URL: http://www.sci.aha.ru/ALL/VOC/index.htm
Wikipedia
A free encyclopedia that anyone can edit. At the moment, Wikipedia contains over 187,000 articles in Russian.
URL: http://ru.wikipedia.org
Glossary
Service of thematic explanatory dictionaries.
URL: http://www.glossary.ru/
World of encyclopedias
Search in Russian-language encyclopedic and pseudo-encyclopedic publications (encyclopedias, encyclopedic dictionaries, encyclopedic reference books). Thematic search is possible.
URL: http://www.encyclopedia.ru/encyclopedias.html
Rubricon
The largest encyclopedic resource on the Internet. Encyclopedias, encyclopedic dictionaries and reference books: Great Soviet, illustrated dictionary, Brockhaus and Efron, Dahl's dictionary, dictionaries "History of the Fatherland" and "World History", Small Medical Encyclopedia, World Encyclopedia of Classical Art, etc. Search is provided. Access to full electronic versions of the most important encyclopedias and dictionaries published over the last hundred years in Russia.
URL: http://www.rubricon.com
Russian biographical dictionary
The Internet version of the Russian biographical dictionary is prepared on the basis of the CD-ROM “Brockhaus and Efron. Encyclopedic Dictionary. Biographies. Russia". It is based on a selection of articles from the 86-volume Encyclopedic Dictionary of Brockhaus and Efron (1890-1907) and the New Encyclopedic Dictionary (1911-1916), unfinished by the publishers. All articles are adapted to the modern Russian language. Alphabetical search. Free access.
URL: http://www.rulex.ru/
Dictionaries and encyclopedias On-line
A large resource of a wide variety of dictionaries and encyclopedias (Dahl's Explanatory Dictionary, BES, Financial, Economic, Historical, Geological Dictionary, Brockhaus and Efron Encyclopedia, 1000 biographies, Ozhegov and Ushakov's Explanatory Dictionary). Allows you to search by word in the title and content of a dictionary entry.
URL: http://dic.academic.ru/
Dictionaries on the server of the Russian Information Network
Large Encyclopedic Dictionary, medical, linguistic and other dictionaries. Several dictionaries of terms by industry, bilingual dictionaries.
URL: http://dictionaries.rin.ru/
ABBYY Lingvo electronic dictionaries
The Lingvo electronic dictionary was created by specialists from the Russian company ABBYY, one of the world's leading software developers in the field of applied linguistics. Offers multilingual electronic dictionaries: English-Russian, Russian-English, German-Russian, Russian-German, French-Russian, Russian-French, Italian-Russian, Russian-Italian, etc.
URL: http://www.lingvo.ru/
Encyclopedias and reference books on the RNL server
Provides links and annotations to encyclopedias and reference books of universal content, translation dictionaries, abbreviations dictionaries, biographical reference books, search reference books, dictionaries, encyclopedias. Information about all directories of the Russian Internet.
URL: http://www.nlr.ru/res/inv/ic_www/cat_show.php?rid=69
Encyclopedias and reference books on the Yandex server
Encyclopedias of universal content, in particular the Great Soviet Encyclopedia, encyclopedias on economics, law, history, and medicine.
URL: http://slovari.yandex.ru/
Encyclopedia of Cyril and Methodius
The collection of 10 online encyclopedias was initially based on the two-volume Great Encyclopedic Dictionary of the 1996 edition, then supplemented by a large number of original articles. Currently contains 130,000 articles and 30,000 illustrations.
URL: http://mega.km.ru/
Endocrinology is closely related to neurology, sexopathology, pharmacology and other fields. Nowadays, it is impossible to find a medical discipline that does not directly or indirectly use the data obtained in endocrinology, because the growth, maturation, reproduction and proper functioning of all organs and systems depend solely on the content of certain hormones in the blood.
Swelling under the eyes, memory loss, sudden weight loss or gain, loss of appetite, thirst, menstrual dysfunction, computer fatigue syndrome - all this can also be a symptom of a hormonal disorder. In this book, the reader will find all the information about the human endocrine system and a detailed description of diseases associated with its changes.
The encyclopedia is intended for practicing doctors and medical students.
Large medical encyclopedia of diagnostics. 4000 symptoms and syndromes
Aurika Lukovkina Medicine AbsentThe large computer encyclopedia is a convenient and competent reference book on the use of modern computer programs and languages. The book includes more than 2,600 English and Russian terms and concepts. The Operating Systems and Programming Reference will introduce you to the five most popular computer languages and thirteen operating systems.
The Keyboard Shortcuts Guide contains all the latest updates for seven popular programs, and the Computer Slang Guide contains nearly 700 terms to help you navigate the computer world. This book will become an indispensable assistant for you and will help you gain new knowledge.
WiMAX Encyclopedia. The path to 4G
Vladimir Mironovich Vishnevsky Computer Hardware AbsentThe book was written by well-known experts in the field of wireless technologies. Published with the assistance and under the auspices of the WiMAX Forum. The monograph describes the principles of construction, logical and physical structure of wireless data networks on an urban/regional scale.
Describes IEEE 802.11 wireless networks, including mesh networks. The architecture and principles of organizing WiMAX networks are described (for the first time in Russian literature). IEEE 802.16 radio access technology, including mobile networks (IEEE 802.16e), is described in detail.
Cellular networks of 3G and LTE standards are described (also for the first time in domestic literature), as well as broadband digital television and radio broadcasting technologies (DVB and DAB). The principles of MIMO technology are outlined. Examples of implementation of regional WiMAX networks are given.
The theoretical foundations of information transmission (theorems of Shannon, Kotelnikov, Nyquist), methods of coding and modulation in wireless networks are outlined. In general, the monograph is a unique reference guide on today's main broadband wireless access technologies, covering issues from network architecture to hardware implementation of devices and principles of equipment certification.
The combination of both the minimum necessary theoretical foundations of wireless telecommunications and descriptions of specific standards, circuit design principles for constructing devices that support them, and examples of implementation of specific wireless networks makes the book useful to a wide range of readers, primarily specialists involved in the construction of broadband wireless networks, developers of telecommunications equipment, heads of IT departments and similar services.
