Let's divide the computer parts into four main groups:

• 1. System unit;
• 2. Peripheral devices.
• 3. Means of manipulation;
• 4. Display media;

System unit, the main part of the computer where all computing processes take place. The system unit is quite complex and consists of various components. We'll look at these components later.

Manipulation means: keyboard, mouse, game joystick. All those devices with the help of which we “tell” the computer what to do, what computing processes to run at the moment.

Display media is, first of all, a monitor. All information about the operation of the computer is displayed on the monitor. The monitor allows you to track what is happening on the computer at a given time, what computing process the computer is busy with.

Peripheral devices are devices that are structurally separated from the system unit. Devices that have their own control and operate according to commands from the system unit. Serve for external data processing. Peripheral devices include printers, scanners, modems, and external storage devices.

System unit device:

The motherboard is the main part of the system unit to which all devices of the system unit are connected. Through the motherboard, the devices of the system unit communicate with each other, exchange information, and supply electricity. The faster the buses (device communication channels) of the motherboard, the faster the devices communicate with each other, the faster the computer works.

The processor is the brain of the system unit, performs logical operations. The speed of the computer and its entire architecture largely depend on its speed and frequency.

RAM is memory for temporary storage of data in a computer, used only when the computer is running. The speed of the computer depends on the amount and speed of RAM.

Hard drive - serves for long-term storage of information; it contains programs necessary for the computer to operate (Windows, Office, Internet Explorer.) and user files (Mail files, if an email client is used, videos, music, pictures.).

A video card is a board inside the system unit, designed to connect the system unit and the monitor, transmits the image to the monitor and takes on part of the calculations for preparing the image for the monitor. The image quality depends on the video card. The video card has its own built-in RAM and its own image processing processor. The higher the frequency of the video card processor and the more memory the video card has, the cooler (later released) games you can play on your computer.

Sound card - designed to prepare sound signals reproduced by speakers. The sound card is usually built into the motherboard, but it can also be structurally separated and connected via a bus.

Network card is a board, device, installed on the motherboard or built into it. A network card is used to connect a computer to other computers via a local network or to connect to the Internet.

CD/DVD-ROM - a device for reading/writing CDs, CDs, DVDs. These devices differ in the speed of reading or writing information, as well as the ability to read / write various media. Nowadays it is difficult to find anything on sale other than omnivorous CD-ROMs. Modern CD-ROMs are capable of reading and writing both CDs and DVDs of various capacities.

A disk drive is a device designed to read/write information on floppy disks. It is rarely installed in modern computers. A card reader is installed in place of disk drives in modern computers.

Card reader is a device for reading/writing information on memory cards. Card readers differ in speed characteristics of reading / writing information. Card readers can be built into the system unit or structurally independent, connected to the system unit via a USB port.

Computer ports are connectors on the system unit designed to connect peripheral devices, manipulator devices and display devices. We won’t talk about the connectors in detail, we’ll just list some of them: USB, VGA, Power connector, COM port, Ethernet port, Standard audio output connector, etc.

The power supply is the unit that powers all devices inside the computer. Power supplies differ in power. The more powerful the power supply, the more devices you can connect inside the system unit.

Coolers are fans designed for air cooling. Typically, coolers are installed inside the power supply, on the processor, or on the video card. An additional cooler can be installed on the system unit to cool the entire unit.

Radiators are metal plates installed to remove heat from processors in the system unit. Radiators are usually cooled by coolers, but not always.

Basic PC peripherals:

The main peripheral devices of a computer include a printer and a scanner. A printer is designed to output information from a computer onto paper. Printers can be divided into laser and inkjet.

Inkjet printers print on paper using ink drawn from cartridges. Printers can be equipped with a different number of cartridges, it all depends on the model. Inkjet printers are usually color. There are inkjet printers that can print photos. Some photo printers can be connected to the camera/phone directly, bypassing the computer. The disadvantage of inkjet printers is that they are expensive to print; ink from paper is usually washed off with water.

Laser printers come in color and black and white. Laser printers print using a laser beam. The laser beam bakes the toner onto the paper, which falls from the cartridge onto the paper. Laser printers differ in printing speed, the number of sheets printed per minute. As a rule, laser printers are found in offices, because... They have a high printing speed and the printed sheet is not expensive in terms of cost. Like inkjet printers, laser printers have cartridges. These cartridges are filled with toner (powder).

Scanner- a device for scanning documents, photographs and even photo negatives. The most common type of scanner is flatbed. Different scanners have different scanning speeds. Scanners can also be divided by the extension they support when scanning. Some scanners have a special device installed for scanning negatives. The scanner is usually connected to the computer via a USB port.

Multifunctional devices - printer / scanner / copier (copier) in one device. Combines all of the above functions. A distinctive feature of such devices is the ability to use them as a copier, bypassing the computer. Such combined devices can be either inkjet or laser.

Manipulation means:

The keyboard and mouse are the main means of manipulating and controlling a computer. Also, the means of manipulation include various joysticks, steering wheels with pedals, steering wheels, but they are intended mainly to control the game process. It can be noted here that not all released games can correctly use or even use one or another game controller.

P.S:

I would like to draw your attention to the fact that progress does not stand still and this article will become outdated over time. But the architecture of the personal computer will not change so soon. Therefore, this text will be useful as an introductory part for studying computers in more detail.

Every day new production technologies appear in the world or old methods are improved. Scientists and engineers are struggling with new inventions. But the “bicycle” has not yet been invented.

Some very zealous opponents of the Stone Age are predicting the imminent extinction of keyboards. They motivate this by the fact that the keyboard will be replaced by speech input. Of course, it would be very nice, but there are, firstly, different languages ​​(it’s not appropriate, for example, for a Russian to speak English), and, secondly, not everyone can do without interjections like “mmm...”, “uh...”, “this is... what’s his name?...” and so on. All this creates problems in writing software, which in principle can be written, but it is difficult, and it requires a lot of resources. At this stage of development of personal computers, even the most primitive speech recognition system, the reliability of which would be sufficient to replace the keyboard, is very demanding on system resources. Therefore, it is unlikely that in the foreseeable future it will go back to the “stone age” (or, more precisely, we will come out of it), so the keyboard will remain the standard and, perhaps, the only means of entering text information for a long time. By the way, how, when the operating system has not yet been loaded, can you enter the BIOS or install this very system? Build support for speech input into the BIOS? Well, that's still a long way off.

Based on the above, you should still pay some attention to choosing a keyboard. When you go to the store for this most “non-evolving” device, pay attention to the following factors:

Ergonomics

Keyboard type

Ease of key press

Interface

Additional features

Let's start in order. It’s not for nothing that I put the ergonomics of the keyboard in first place, because, in my opinion, this is the main thing - if the keyboard is not comfortable, then it’s unlikely that a fast processor and a powerful video card will be able to correct the situation, and it’s better not to skimp on the keyboard. After all, you may have to type dozens of megabytes of text on it, and if you have worked a lot with text on a bad keyboard, you should know that the latter greatly darkens the whole picture. And many users, unfortunately, pay very little attention to this and are guided by the principle “the cheaper, the better.” And in vain. Although, on the other hand, when you play Unreal, the quality of the keys is not particularly important, but pressing good keys is still more pleasant, and it’s not all the time to play Unreal! Therefore, do not regret a few extra dollars (although I, however, have hardly met people who have “extra” dollars) and buy a good keyboard.

Ergonomics

Ergonomics can be understood as all the properties of a keyboard that are related to comfort. We will discuss only the most, in my opinion, important of them.

The location of the keys, as well as their shape, size, and so on. There are several keys that can have different shapes and sizes: BackSpase, Enter, Shift.

There are two types of BackSpase key: large or small. It is preferable, of course, to have a large one, because it is easier to hit, but the price for this is the displacement of the slash key down and, as a result, a small Enter key.

Which can also be big. But the small size is quite enough, so, in my opinion, it is better, considering that the BackSpase becomes large. True, there are keyboards that have large BackSpace and Enter, but then the right Shift is shortened, which is very bad. If the Enter key is large, then there are also two options: in the form of the letter “L”, turned in the other direction, and in the form of the letter “G”. The last option is the most inconvenient, since pressing usually occurs on the near part of the key, and with the L-configuration it is easy to hit adjacent keys.

As already mentioned, depending on the size of Enter and Backspace, the Shift (right) key may become smaller. This is extremely undesirable, because Shift is used often, especially in combination with other keys, and it is quite easy to miss it in this case. For example, to switch the keyboard layout it is easy to use the Cntrl+Shift combination, but when this Shift is small, it becomes not so convenient. True, you can use the left Shift, but two hands must be used when typing.

Therefore, choose a keyboard with large Shift and BackSpace and small Enter. A good alternative is also the following key configuration: small BackSpace, large L-shaped Enter and large Shift key. But the first option, it seems to me, is better.

There are keyboards with the so-called Eraze-Eaze configuration, in which the space bar is divided into two halves. One of them (optional) serves as the space bar, and the other serves as the BackSpace key. This was again done for convenience, but the dubiousness of the idea lies in the contradiction with the basic rule of touch typing, according to which the space bar is pressed by the free (and therefore any) hand. That is, if the last letter of a word is entered by one hand, then the subsequent space is entered by the other. Fortunately, in the case of Eraze-Eaze, you don’t have to program the halves, leaving the Space function for both. Some keyboard models may have a larger Escape. This feature can be considered a plus, because it becomes easier to get to. True, this is easy to do anyway, because Escape is always located separately.

Due to the advent of operating systems that allow you to manage power, modern keyboards usually (though not necessarily always) have three so-called sleep keys, allowing you to sleep, wake up and turn on / off the computer. Whether these keys are needed is up to you to decide, but if they are, pay attention to their location. There are three options: the keys are located next to the page keys in the bottom row, the keys are located next to the page keys in the top row, the sleep keys are located above the Break group, and the Break group is pushed down and merges with the page keys. The last option is bad because if you are used to pressing Insert (for example, Shift+Insert), then due to a change in the usual arrangement of keys, you can press PrintScreen, and an image of 3-4 megabytes or more will be pushed into the buffer (depending on resolution and color palette), and even the previous contents will be overwritten. The second arrangement is even “better” - when you click on the supposed Insert, you will actually press the power key. Therefore, the first option, in my opinion, is the best.

For those who use the great and mighty Russian language, it is important how the Russian keyboard layout is made and what color the Russian letters are printed in. The Cyrillic alphabet layout can be Russian (Russian) and Russian typewriter (Russian Typewriter). The typewritten layout, as the name suggests, repeats the keys of a typewriter. It was almost the standard until the advent of Windows, in which a new layout appeared. They are almost the same, but in Russian they were introduced small but effective improvements. For example, the almost unused letter “е” was moved to a far corner, and in its place a key was placed with the often used period and comma. In the typescript layout, they are moved to the top row and entered in upper case. Somewhat awkward that a foreign company developed a more advanced layout for us.

The Cyrillic layout, of course, depends only on the driver (Windows usually has Russian after installation, but you can change it), and you can buy stickers or simply remember the location of inappropriate inscriptions. But is it worth doing this? Therefore, choose a keyboard with a Russian layout. By the way, others are no longer produced. The color of the applied Cyrillic alphabet is also of no small importance. It’s better, of course, red, since the red color is immediately noticeable, but this is basically a matter of habit. Although preference should probably still be given to red.

Microsoft once spent almost two years developing a new type of keyboard designed for Windows 95. This keyboard was called the Natural Keyboard. In the literal translation - a natural keyboard, in the literary translation - an ergonomic one. Subsequently, this name became a household name. Natural Keyboard has vertical rows of keys oriented to the sides, corresponding to the area of ​​each hand. The user is relieved of the stress of holding his hands parallel to each other. The profile of the alphabetic part of the keyboard represents a convex arc. This eliminates the need to keep your hands parallel to the plane of the table. There is a stand for resting your hands. After looking at the Natural Keyboard, it becomes clear that previous keyboards simply inherited the conservative style of typewriters. Natural Keyboard served as an example to follow. However, manufacturers sometimes do not hesitate to call their keyboards ergonomic if they have at least one of the three considered innovations of the original Microsoft keyboard. Perhaps the only drawback of such keyboards is the space they take up. If you work a lot with text and you are not limited by space, then purchase an ergonomic keyboard. It should be noted that they are significantly more expensive than regular ones.

Later, broken keyboards appeared, allowing you to adjust the angle of rotation of the two halves. Each half has its own legs, so you can also adjust the tilt in different directions. Some went even further and came up with a keyboard generally consisting of two halves. This can be quite convenient, but you can’t put such a keyboard on your lap like a hacker.

The palm rest introduced in MS Natural Keyboard has now extended to regular keyboards. It is intended for resting the hands, and not for their working position: according to the rules, the hands should be half-bent and hanging over the keys. That's why it's called Palm Rest. However, how many people follow these rules, leaning their wrists on the table when working (I myself am one of them)? For the latter, the stand will be a significant relief, especially in the case of tall keyboards. The stand also improves the appearance, especially when done in a different color. The stands are detachable and molded. Clearly, a detachable stand is a more flexible solution that allows you to seamlessly transition to a keyboard without a stand. If the stand is detachable, then it is good that it has a fastening that allows some rotation relative to the fastening line, so that when tilting the keyboard using the legs, the stand does not bend. Choose keyboards with detachable stands. Note that the palm rest is sold separately as an accessory, so owners of keyboards without a stand can get one at any time.

The system unit contains the following elements (not necessarily all at once), which are connected to the motherboard using connectors (slots):

1. Power supply. It powers the computer.

2. A hard disk drive (HDD -- hard disk drive) is more often called a hard drive. This nickname arose from the slang name for the first model of a hard drive with a capacity of 16 KB (IBM, 1973), which had 30 tracks of 30 sectors, which coincidentally coincided with the "30/30" caliber of the famous "Winchester" hunting rifle. The capacity of this drive is usually measured in gigabytes: from 20 GB (on old computers) to several Terabytes (1 TB = 1024 GB). The most common hard drive capacity is 250-500 GB. The speed of operations depends on the rotation speed (5400-10000 rpm). Depending on the type of connection between the hard drive and the motherboard, ATA and IDE are distinguished.

3. A floppy disk drive (FDD -- floppy disk drive) is nothing more than a floppy drive for floppy disks. Their standard capacity is 1.44 MB with a diameter of 3.5" (89 mm). Magnetic disks use magnetic materials with special properties as a storage medium that allows them to record two magnetic states, each of which is assigned binary digits: 0 and 1.

4. Optical disk drives (CD-ROM) come in different diameters (3.5" and 5.25") and capacities. The most common of them are with a capacity of 700 MB. It happens that CD discs can be used for recording only once (then they are called R), and it is more profitable to use repeatedly rewritable RW discs.

5. DVD originally stood for Digital Video Disk. Despite the name, DVDs can record anything from music to data. Therefore, recently another decoding of this name has become increasingly common - Digital Versatile Disk, loosely translated meaning “digital universal disk”. The main difference between DVDs and CDs is the amount of information that can be recorded on such media. From 4.7 to 13, and even up to 17 Gb can be recorded on a DVD disc. This is achieved in several ways. First, reading DVDs uses a laser with a shorter wavelength than reading CDs, which has significantly increased recording density. Secondly, the standard provides for so-called double-layer disks, in which on one side the data is recorded in two layers, while one layer is translucent, and the second layer is read “through” the first. This made it possible to write data to both sides of DVDs, thereby doubling their capacity, which is sometimes done.

6. Other additional devices (mouse, printer, scanner, etc.) can be connected to the personal computer. The connection is made through ports - special connectors on the rear panel. The ports are parallel (LPT), serial (COM) and universal serial (USB). A serial port transmits information bit by bit (slower) over a small number of wires. A mouse and modem are connected to the serial port. Through a parallel port, information is transmitted simultaneously over a large number of wires corresponding to the number of bits. A printer and an external hard drive are connected to the parallel port. The USB port is used to connect a wide range of peripheral devices - from a mouse to a printer. Data exchange between computers is also possible.

7. The main devices of the computer (processor, RAM, etc.) are located on the motherboard.

1) Microprocessor (simply processor) is the central unit of a PC, designed to control the operation of all blocks of the machine and to perform arithmetic and logical operations on information. Its main characteristics are the bit depth (the higher it is, the higher the computer’s performance) and clock speed frequency (largely determines the speed of the computer). The clock frequency indicates how many elementary operations (cycles) the processor performs in one second. Intel Pentium processors and its economical version of Celeron are respected in the market, and their competitors are also appreciated - AMD Athlon with an economical version of Duron. Intel processors are characterized by high reliability, low heat generation and compatibility with all software and hardware. And AMD shows greater speed with graphics and games, but is less reliable.

2) Computer memory can be internal or external. External memory devices include the already discussed HDD, FDD, CD-ROM, DVD-ROM. Internal memory includes permanent storage (ROM, ROM), random access memory (RAM), Cache

ROM is designed to store permanent program and reference information (BIOS - Basic Input-Output System - basic input-output system).

RAM is fast and is used by the processor for short-term storage of information while the computer is running. When the power source is turned off, information is not saved in RAM. For the normal functioning of a computer these days, it is advisable to have from 1 GB to 3 GB of RAM.

Cache memory is an ultra-high-speed intermediate memory.

CMOS memory -- CMOS RAM (Complementary Metall-Oxide Semiconductor RAM). It stores computer configuration settings that are checked every time the system is turned on. To change computer configuration settings, the BIOS contains a computer configuration program - SETUP.

8. Sound, video and network cards can be either built into the motherboard or external. External boards can always be replaced, whereas if the built-in video card fails, you will have to replace the entire motherboard. The most commonly used video cards are ATI Radeon and Nvidia. The higher the video card memory, the better.

Peripherals.

The main peripheral devices of a computer include a printer and a scanner. A printer is designed to output information from a computer onto paper. Printers can be divided into laser and inkjet.

Inkjet printers print on paper using ink drawn from cartridges. Printers can be equipped with a different number of cartridges, it all depends on the model. Inkjet printers are usually color. There are inkjet printers that can print photos. Some photo printers can be connected to the camera/phone directly, bypassing the computer. The disadvantage of inkjet printers is that they are expensive to print; ink from paper is usually washed off with water.

Laser printers come in color and black and white. Laser printers print using a laser beam. The laser beam bakes the toner onto the paper, which falls from the cartridge onto the paper. Laser printers differ in printing speed, the number of sheets printed per minute. As a rule, laser printers are found in offices, because... They have a high printing speed and the printed sheet is not expensive in terms of cost. Like inkjet printers, laser printers have cartridges. These cartridges are filled with toner (powder).

A scanner is a device for scanning documents, photographs and even photo negatives. The most common type of scanner is flatbed. Different scanners have different scanning speeds. Scanners can also be divided by the extension they support when scanning. Some scanners have a special device installed for scanning negatives. The scanner is usually connected to the computer via a USB port.

Multifunctional devices - printer/scanner/copier (copier) in one device. Combines all of the above functions. A distinctive feature of such devices is the ability to use them as a copier, bypassing the computer. Such combined devices can be either inkjet or laser.

Means of manipulation

The keyboard and mouse are the main means of manipulating and controlling a computer. Also, the means of manipulation include various joysticks, steering wheels with pedals, steering wheels, but they are intended mainly to control the game process. It can be noted here that not all released games can correctly use or even use one or another game controller.

Units.

Many people are interested in the computer, its programs and other computer accessories, but few people have thought about the fact that all files in the form of pictures, videos, music are stored on the computer using its memory. And it happens like this: The computer must have a storage device (HDD disk, flash disk, etc.) - this is it. The computer's memory is not infinite, so the file should not exceed the size of the free memory of the drive. In the not-too-distant past, PC memory was stored on disks that were capable of storing text smaller than a given one, but they were the size of a room, and now a box-sized computer is capable of remembering hundreds of thousands of such texts, or even more.

Let's explain all this in the language of computer science:

Memory- in computer science - the ability of an object to provide data storage. Storage is carried out in storage devices.

Address- a number that identifies individual parts of memory (cells) and registers.

Associative memory- in computer science - addressless memory, in which information is searched according to its content (associative feature).

Bit- the minimum unit of measurement of the amount of transmitted or stored information, corresponding to one binary digit capable of taking the values ​​0 or 1.

Byte- in storage devices - the smallest addressable unit of data in computer memory processed as a single whole. By default, a byte is considered to be 8 bits. Typically in data encoding systems, a byte represents the code for a single printable or control character.

Byte- in the measurement of information - a unit of measurement of the amount of information, memory volume and storage capacity and the basis of derived units: -

1 byte = 8 bits,

1 kilobyte = 1024 bytes,

1 megabyte = 1024 KB,

1 gigabyte = 1024 MB,

1 terabyte = 1024 GB,

1 petabyte = 1024 TB.

On the Internet there is such a thing as connection speed. It is measured not in bytes, but in bits. Those. Data loading occurs (under reference conditions) at a speed 8 times less than the connection speed to the node. (since there are 8 bits in 1 byte)

Example: the actual capacity of the communication channel is 1 Mbit/sec., i.e. 1024Kbps. Accordingly, the maximum data download speed through such a bandwidth = 1024/8 → 128 KB/sec. With this connection, a 10 MB file will download in 10/0.128 = 80 seconds

Principles of PC operation

Let's consider the principle of operation of a personal computer

The structure of a computer is somewhat reminiscent of the structure of a person. The processor, RAM and hard drive perform the functions of the brain; the motherboard and chipset are the circulatory and nervous systems; keyboard, mouse, microphone, scanner and webcam (input devices) are similar to human vision, hearing and other functions of sensing the surrounding world; monitor and printer (output devices) are something like a language. From the technical side, the principle can be described as follows:

A certain amount of information has appeared. The device that receives the information processes it and prepares it for sending using a common protocol. Such a device can be called a transmitter. Then, another device designed for data transmission transmits the prepared information. The receiver or, as you already understood, the device receiving the information read the data using the same protocol and, based on some information that was stored earlier, made a decision. As a response, this data was sent back using the same communication device. This is roughly how computer devices work with each other: they constantly process something and exchange data, using common protocols that specify how to transmit and receive this data.

All information is stored on the hard drive. When you turn on the computer, part of the data necessary for the normal functioning of the system is loaded into random access memory (RAM - random access memory). In addition, other devices can also send their data there while the computer is running. The processor (CPU - central processing unit) is responsible for processing data. Information enters the CPU from RAM, and after processing it is returned there. And then it can be sent to the recipient, that is, to the device that sent this data to RAM for subsequent processing (although this does not always happen, but more on that later). If you need to save information for a long time, then you “dump” it onto the hard drive, since RAM can store data only if it is constantly supplied with power. If some device suddenly wants the CPU to process something for it, then first you need to prepare the data, then send it to memory and tell the processor that this data needs to be processed. Wait, and then maybe (depending on the task) receive the processed data back, or maybe send it to some other device. There are many devices, but there is only one processor and there is not enough of it for all of them. What to do? It's very simple - get in line and wait. There is a hierarchy among devices. For some, the CPU will process the data immediately, while others will have to wait until the second coming.

It is clear that the user must observe some result of his work. This is what the monitor is designed for, the data for which is prepared by the video card (by the way, it is this device that can access the CPU, bypassing the RAM).

For example: You launched MS Word and pressed some key, say [G]. A letter appeared on the screen in the text field and, not least important, it was the letter G. What happened? Firstly, by launching the MS Word program, you gave it control of the computer (which is also controlled by the operating system). Secondly, pressing the [G] key caused the keyboard mini-processor to send the code for this key to the computer. Thirdly, the processor, having processed the command and data that was prepared by the program, sent it to the video card. Fourthly, the video card, having received the command and data and processed it in its own way, sent everything to the monitor, and it, in turn, output what was ordered. All. You see the letter G on the screen. From the last example we can conclude that a computer is not only its hardware, but also its software. That is, one is not separable from the other. Moreover, I will tell you - any computer device has its own control program, which is called a driver. Without such programs, most computer devices will not work. The operating system (OS) takes over overall control of the computer. By the way, this is the weakest point of a modern PC. In general, it should be noted that all PCs operate according to von Neumann principles of program control. A Hungarian by nationality, John von Neumann emigrated to the USA in 1930, where in 1945 he developed the principles of computer program control. And to this day, the world of information technology uses these rules (albeit not the most convenient and having their own shortcomings), since no one can really offer anything else (there are also non-Fonneym computers, but they still have even greater shortcomings). Here are the rules:

1. The principle of binary coding. This means that all information in a computer is transmitted and stored in binary form.

2. The principle of program control. Here we are talking about the fact that a program is a set of commands that the processor executes automatically and in a certain sequence.

3. The principle of memory homogeneity. Different types of information differ in the way they are used, and not in the way they are encoded.

4. The principle of targeting. Information is stored in memory cells that have a precise address. Knowing the address, the CPU can access the necessary information at any time.

PC device

Let's divide the computer parts into four main groups:

· System unit:

System unit, the main part of the computer where all computing processes take place. The system unit is quite complex and consists of various components. We'll look at these components later.

· Peripherals:

Peripheral devices are devices that are structurally separated from the system unit. Devices that have their own control and operate according to commands from the system unit. Serve for external data processing. Peripheral devices include printers, scanners, modems, and external storage devices.

· Manipulation means:

Manipulation means: keyboard, mouse, game joystick. All those devices with the help of which we “tell” the computer what to do, what computing processes to run at the moment.

· Display media:

Display media is, first of all, a monitor. All information about the operation of the computer is displayed on the monitor. The monitor allows you to track what is happening on the computer at a given time, what computing process the computer is busy with.

System unit device:

· Motherboard– the main part of the system unit to which all devices of the system unit are connected. Through the motherboard, the devices of the system unit communicate with each other, exchange information, and supply electricity. The faster the buses (device communication channels) of the motherboard, the faster the devices communicate with each other, the faster the computer works.

· CPU– the brain of the system unit, performs logical operations. The speed of the computer and its entire architecture largely depend on its speed and frequency.

· RAM– memory for temporary storage of data in a computer, used only when the computer is running. The speed of the computer depends on the amount and speed of RAM.

· HDD– serves for long-term storage of information; it contains programs necessary for computer operation (Windows, Office, Internet Explorer.) and user files (Mail files, if an email client is used, videos, music, pictures).

· Video card– a board inside the system unit, designed to connect the system unit and the monitor, transmits the image to the monitor and takes on part of the calculations to prepare the image for the monitor. The image quality depends on the video card. The video card has its own built-in RAM and its own image processing processor. The higher the frequency of the video card processor and the more memory the video card has, the cooler (later released) games you can play on your computer.

· Sound card– designed to prepare sound signals reproduced by speakers. The sound card is usually built into the motherboard, but it can also be structurally separated and connected via a bus.

· LAN card- a board, device, installed on the motherboard or built into it. A network card is used to connect a computer to other computers via a local network or to connect to the Internet.

· CD/DVD-ROM– a device for reading/writing CDs, CDs, DVDs. These devices differ in the speed of reading or writing information, as well as the ability to read/write various media. Nowadays it is difficult to find anything on sale other than omnivorous CD-ROMs. Modern CD-ROMs are capable of reading and writing both CDs and DVDs of various capacities.

· Drive– a device designed for reading/writing information on floppy disks. It is rarely installed in modern computers. A card reader is installed in place of disk drives in modern computers.

· Card reader– a device for reading/writing information on memory cards. Card readers differ in speed characteristics for reading/writing information. Card readers can be built into the system unit or structurally independent, connected to the system unit via a USB port.

· Computer ports– connectors on the system unit designed for connecting peripheral devices, manipulator devices and display devices. We won’t talk about the connectors in detail, we’ll just list some of them: USB, VGA, Power connector, COM port, Ethernet port, Standard audio output connector, etc.

· power unit– a unit that powers all devices inside the computer. Power supplies differ in power. The more powerful the power supply, the more load it can “hold”

· Coolers– fans designed for air cooling. Typically, coolers are installed inside the power supply, on the processor, or on the video card. An additional cooler can be installed on the system unit to cool the entire unit.

· Radiators– metal plates installed to remove heat from processors in the system unit. Radiators are usually cooled by coolers, but not always.

Basic PC peripherals:

The main peripheral devices of a computer include a printer and a scanner. A printer is designed to output information from a computer onto paper. Printers can be divided into laser and inkjet.

· Inkjet printers printed on paper using ink taken from cartridges. Printers can be equipped with a different number of cartridges, it all depends on the model. Inkjet printers are usually color. There are inkjet printers that can print photos. Some photo printers can be connected to the camera/phone directly, bypassing the computer. The disadvantage of inkjet printers is that they are expensive to print; ink from paper is usually washed off with water.

· Laser printers come in color and black and white. Laser printers print using a laser beam. The laser beam bakes the toner onto the paper, which falls from the cartridge onto the paper. Laser printers differ in printing speed, the number of sheets printed per minute. As a rule, laser printers are found in offices, because... They have a high printing speed and the printed sheet is not expensive in terms of cost. Like inkjet printers, laser printers have cartridges. These cartridges are filled with toner (powder).

· Scanner– a device for scanning documents, photographs and even photo negatives. The most common type of scanner is flatbed. Different scanners have different scanning speeds. Scanners can also be divided by the extension they support when scanning. Some scanners have a special device installed for scanning negatives. The scanner is usually connected to the computer via a USB port.

· Multifunction devices– printer/scanner/copier (copier) in one device. Combines all of the above functions. A distinctive feature of such devices is the ability to use them as a copier, bypassing the computer. Such combined devices can be either inkjet or laser.

· Graphics tablet– a device for manually entering graphic information and images by moving a special pointer (pen) across the tablet; When you move the pen, the coordinates of its location are automatically read and these coordinates are entered into the PC

Manipulation means:

· Keyboard and mouse- these are the main means of manipulating and controlling a computer. Also, the means of manipulation include various joysticks, steering wheels with pedals, steering wheels, but they are intended mainly to control the game process. It can be noted here that not all released games can correctly use or even use one or another game controller.

DDR SDRAM

Compared with conventional SDRAM, the bandwidth was doubled with double the data transfer rate. (Initially, this type of memory was used in video cards, but later support for DDR SDRAM appeared on the chipset side.)

For reference: DDR SDRAM memory operates at frequencies of 100, 133, 166 and 200 MHz, its full access time is 30 and 22.5 ns, and its duty cycle time is 5, 3.75, 3 and 2.5 ns. Examples of memory module designations: DDR200, DDR266, DDR333, DDR400

DDR2 SDRAM

Structurally, a new type of RAM DDR2 SDRAM was released in 2004. Based on DDR SDRAM technology, this type of memory, due to technical changes, shows higher performance and is intended for use on modern computers.

For reference: the memory can operate at bus clock speeds of 200, 266, 333, 337, 400, 533, 575 and 600 MHz. In this case, the effective data transmission frequency will be 400, 533, 667, 675, 800, 1066, 1150 and 1200 MHz, respectively. Some manufacturers of memory modules, in addition to standard frequencies, also produce samples operating at non-standard (intermediate) frequencies. They are intended for use in overclocked systems where frequency headroom is required. Full access time - 25, 11.25, 9, 7.5 ns or less. Duty cycle time - from 5 to 1.67 ns.

DDR3 SDRAM

This type of memory is based on DDR2 SDRAM technologies with twice the data transfer frequency on the memory bus. It features lower power consumption compared to its predecessors. The bandwidth frequency ranges from 800 to 2400 MHz (the frequency record is more than 3000 MHz), which provides greater throughput compared to all predecessors.

DRAM memory designs

DRAM type memory is structurally implemented in the form of separate microcircuits in DIP, SOIC, BGA type packages and in the form of memory modules of the SIPP SIMM, DIMM, RIMM type (for PCI connectors of system units)

The figure below the case shows: from top to bottom: DIP, SIPP, SIMM (30-pin), SIMM (72-pin), DIMM (168-pin), DIMM (184-pin, DDR)

As an example, the case versions of RAM cards used in modern laptops are provided:

HDD.

Hard disk drive or HDD(English: hard (magnetic) disk drive, HDD, HMDD), hard disk, in computer slang “winchester”, “screw”, “hard”, “hard disk” is an information storage device based on the principle of magnetic recording. It is the main data storage device in most computers.

Unlike a “floppy” disk (floppy disk), information in a hard disk drive is recorded on hard (aluminum or glass) plates coated with a layer of ferromagnetic material, most often chromium dioxide. HDD uses one or more plates on one axis. In operating mode, the reading heads do not touch the surface of the plates due to the layer of incoming air flow that forms near the surface during rapid rotation. The distance between the head and the disk is several nanometers (about 10 nm in modern disks), and the absence of mechanical contact ensures a long service life of the device. When the disks do not rotate, the heads are located at the spindle or outside the disk in a safe area, where their abnormal contact with the surface of the disks is excluded.

Also, unlike a floppy disk, the storage medium is combined with a storage device, a drive and an electronics unit and (in personal computers in the vast majority of cases) is usually installed inside the computer system unit.

Main characteristics

Interface(English interface) - a set of communication lines, signals sent along these lines, technical means supporting these lines, and exchange rules (protocol). Commercially available internal hard drives can use ATA (aka IDE and PATA), SATA, eSATA, SCSI, SAS, FireWire, SDIO and Fiber Channel interfaces.

Capacity(English capacity) - the amount of data that can be stored by the drive. Since the creation of the first hard drives, as a result of continuous improvements in data recording technology, their maximum possible capacity has been continuously increasing.

Physical size(form factor) (English dimension). Almost all modern drives for personal computers and servers are either 3.5 or 2.5 inches wide - the size of standard mounts for them in desktop computers and laptops, respectively. 1.8-inch, 1.3-inch, 1-inch and 0.85-inch formats have also become common. Production of drives in 8 and 5.25 inch form factors has been discontinued.

External HDD drive

An external HDD drive is a regular hard drive placed in a case and having a USB or FireWire output for connecting to a computer or other device with which you need to exchange data. External USB hard drives became popular in the 2000s, thanks to the general “mobilization”. Portable hard drives differ primarily in capacity and speed.

In practice, external USB HDDs have exactly the same capacities as regular ones, so now you can buy an external HDD with a capacity of up to 1 TB. Currently, external hard drives are produced by more than 30 companies around the world.

Network adapters.

Wired network controllers

Network card, also known as a network card, network adapter, Ethernet adapter, NIC (English network interface card) is a peripheral device that allows a computer to communicate with other devices on the network. Nowadays, especially in personal computers, network cards are quite often integrated into motherboards for convenience and to reduce the cost of the entire computer as a whole.

Types of network cards:

internal- separate cards inserted into an ISA, PCI or PCI-E slot;

external, connecting via USB or PCMCIA interface, previously mainly used in laptops;

built-in into the motherboard.
On 10 megabit Network cards use 4 types of connectors to connect to a local network:

· 8P8C for twisted pair;

· BNC connector for thin coaxial cable;

· 15-pin transceiver AUI connector for thick coaxial cable.

Optical connector (en:10BASE-EL and other 10 Mbit Ethernet standards)

These connectors can be present in different combinations, sometimes even all three at once, but only one of them is working at any given time.

On 100 megabit boards install either a twisted pair connector (8P8C, also known as RJ-45) or an optical connector (SC, ST, MIC). Next to the twisted pair connector, one or more information LEDs are installed to indicate the presence of a connection and the transfer of information. Since our networks within the entrance are built using Fast Ethernet technology - The network card must support 8P8C connector.

It is customary to separate several generations of network controllers. Network adapters produced today can be classified as fourth generation. These adapters necessarily include an ASIC that performs MAC-level functions (MAC-PHY), the speed is up to 1 Gbit/s, and there are also a large number of high-level functions. The set of such functions may include support for the RMON remote monitoring agent, a frame prioritization scheme, functions for remote computer control, etc. In server versions of adapters, it is almost necessary to have a powerful processor that offloads the central processor.

Wireless network controllers

WI-FI is a technology that allows you to create computer networks that fully comply with the standards for conventional wired networks (for example, Ethernet), without the use of cable wiring. The transmission medium in such networks is radio waves 2.4 and 5 GHz

Wireless network controller. As you can understand, this is an adapter that connects your computer to a wireless network.

Wi-Fi controllers come in several types:

· Built-in. Already built into the motherboard. Most often used in laptops or PDAs. As a rule, you cannot remove the built-in controller from your computer, but you can disable it and use another one instead. Most modern laptops are equipped with built-in Wi-Fi controllers. It is worth highlighting mass-produced controllers built on chips: Atheros, Broadcom, VIA, Realtek.

Internal with PCI interface. Perhaps one of the most common types of network controllers for personal computers. Typically, these network cards have one LED, an operation indicator and an antenna socket. The boards can be supplied with different types of antennas: pin, which is installed directly on the adapter bar, and remote.

Internal with PCMCIA interface. The most convenient way to add wireless network support to a laptop that is not equipped with such support by default. They have a built-in antenna, are compact and easy to set up. There are also adapters with folding large antennas that provide increased range of the wireless network.

External USB controllers with USB interface. This is the most versatile type of controller and the most convenient. You can use the USB controller with both a laptop and a personal computer. This type of controller is especially relevant for owners of SFF format computers, such as Shuttle XPC. Such controllers are convenient to carry with you and can be taken on a trip, or vice versa - kept at home or in the office as spare ones, in case you have guests with laptops without Wi-Fi controllers, but who desperately need the Internet on their machines.

Basics of Information Networks

Computer network concept

Let's start with the definition of a computer network.

A computer network is two or more computers connected by a transmission medium (for example, a network cable). The main function of the network is to provide the opportunity to exchange information between network users.

The same concept fits into the principle of resource sharing, when a network user can access information, a program or device located on another computer. For example, network users can work with network programs and files on a remote computer or print on a printer that is physically connected to a computer on the network. To implement network access to resources, programs, files or printers must be shared.

Evolution of networks

The first multi-terminal systems appeared in the early 60s as a way to organize users’ computing work. The operating principle of multi-terminal systems is to divide the computing resources of one powerful computer between a certain number of users. The terminals only display information on the display and provide keyboard input. A large and powerful computer takes on the entire computing load. In the 60s, such computers were IBM mainframes - powerful and reliable universal-purpose computers.

WAN (wide area networks)

The first global networks (Wide Area Network - WAN) appeared as a result of solving the problem of terminal access to a central computer located at a great distance from it, on the order of hundreds of kilometers. And in order to connect central computers with each other, a type of computer-to-computer communication was developed. It became possible to access the resources of several large supercomputers from the terminal. Some network services, such as file sharing, e-mail, and others, have been implemented using the computer-to-computer communication type.

LAN (local area networks)

The first local networks (Local Area Network - LAN) appeared in the early 70s as a result of a technological breakthrough in the field of electronics - large integrated circuits appeared. Large computers were replaced by mini-computers, which were much cheaper and were not inferior in performance to mainframes. Thus, each department of the enterprise had the opportunity to install its own multi-terminal system. And in order to connect departmental systems into a single enterprise network, various non-standard interface devices were used.

Standard LANs

The next step in the evolution of computer networks was the emergence of the first personal computers (PCs). It was the advent of the PC that gave impetus to the standardization of local network technologies. In the mid-80s, standards such as Ethernet, Arcnet, and Token Ring appeared. Thanks to standards, the process of deploying local networks has become easier. To deploy a network, it is enough to install standard network adapters, for example, Ethernet, connect them with a standard cable using standard connectors, and install an operating system (OS) on the computer that supports standard network protocols.

Network classification

LAN (Local Area Networks) are networks that connect computers within one or more adjacent buildings.

A distinctive feature of local networks is the use of high-speed, highly reliable transmission media, such as coaxial cable or twisted pair. Distances covered by local networks usually do not exceed several kilometers.

WAN (Wide Area Networks) are networks that connect computers or local networks that are separated from each other over long distances. Global networks can connect different cities, countries and even continents. An example of a global network is the World Wide Web. A distinctive feature of global networks is the use of a variety of data transmission technologies, including over low-quality lines. This determines the use of highly reliable protocols in global networks that can guarantee data delivery without loss or distortion. In addition, data transfer speeds in wide area networks are typically significantly lower compared to local area networks.

MAN (Metropolitan Area Networks - regional networks). It is not always customary to distinguish this class as a separate one when classifying networks. It refers to networks covering distances of up to hundreds of kilometers. As a rule, they unite local networks of a single administrative subordination. Typically, the transport basis of such networks is formed by high-speed networks using optical fiber as a transmission medium.

Logical topology of the ER-Telecom network

The structure of the ER-Telecom cable network involves four levels. The first three are optical: main (city level), sub-main (campus level) and house inputs (mini-campus level). The fourth level is electrical (house distribution networks). The trunk level combines the central headend station with the headend stations. Currently, the backbone layer has a star topology. The sub-main level connects the Sub-Head Stations (USS) with the mini-campus nodes. All intra-campus wiring is carried out using a four-core optical cable. Two wires are used for cable television needs, two for Internet needs. An optical coupler is installed at each house, which divides the optical signal as a percentage. The topology of the sub-backbone layer is an optical ring. Each mini-campus node serves 24 fiber-connected houses. This scheme allows you to cover the maximum number of houses. The ring connection topology used by ER-Telecom allows, firstly, to increase the economic efficiency of network construction. Ring connection saves cable. Secondly, the use of coaxial cable for external installation between houses is minimized. The ring circuit for connecting mini-campus nodes provides for redundant optics for supplying a television signal. Thus, when the optical ring breaks, the optical signal is switched in the opposite direction. This significantly increases the reliability of the network.

TIRE

In networks with a “Bus” topology, computers are connected to one cable. Information can be distributed along the cable in both directions. The advantages of networks with the “Bus” topology are low cost and ease of cabling. The cable is connected to the computer's network card using a special T-shaped connector.

Disadvantages - low reliability (any defect in the cable system causes the entire network to fail) and low performance, because Only one computer can transmit at a time.

STAR

In networks with a “Star” topology, computers are connected to a central hub (hub), which serves to transmit information from one of its ports to all others. The advantages are higher fault tolerance, since only the failure of the hub can lead to a network shutdown. In addition, some concentrator models can act as intelligent filters that control the flow of information or block transmissions prohibited by the administrator. Disadvantages - additional costs for equipment and network installation.

RING

In networks with a ring topology, computers are connected in series, completing a ring. Information circulates around the ring in one direction. Networks with a ring topology provide a convenient opportunity for the sender to control whether the message was received correctly, because The data, having completed circulation, will return to the sender. The disadvantages of such networks include the complexity of algorithms for monitoring and restoring the integrity of the ring.

Computer - a device or system capable of performing a specified, clearly defined, variable sequence of operations. These are most often operations of numerical calculations and data manipulation, but this also includes operations I/O . The description of the sequence of operations is called program.

Computer device

System unit

System unit, the main part of the computer where all computing processes take place. The system unit is quite complex and consists of various components. We'll look at these components later.

Manipulation means: keyboard, mouse, game joystick. All those devices with the help of which we “tell” the computer what to do, what computing processes to run at the moment.

Monitor

Display media is, first of all, a monitor. All information about the operation of the computer is displayed on the monitor. The monitor allows you to track what is happening on the computer at a given time, what computing process the computer is busy with.

Peripheral devices are devices that are structurally separated from the system unit. Devices that have their own control and operate according to commands from the system unit. Serve for external data processing. Peripheral devices include printers, scanners, modems, and external storage devices.

System unit device:

Motherboard

The motherboard is the main part of the system unit to which all devices of the system unit are connected. Through the motherboard, the devices of the system unit communicate with each other, exchange information, and supply electricity. The faster the buses (device communication channels) of the motherboard, the faster the devices communicate with each other, the faster the computer works.

CPU

The processor is the brain of the system unit and performs logical operations. The speed of the computer and its entire architecture largely depend on its speed and frequency.

RAM

RAM is memory for temporary storage of data in a computer, used only when the computer is running. The speed of the computer depends on the amount and speed of RAM.

HDD

Hard drive – serves for long-term storage of information; it contains programs necessary for the computer to operate (Windows, Office, Internet Explorer.) and user files (Mail files, if an email client is used, videos, music, pictures.).

Video card

A video card is a board inside the system unit, designed to connect the system unit and the monitor, transmits the image to the monitor and takes on part of the calculations for preparing the image for the monitor. The image quality depends on the video card. The video card has its own built-in RAM and its own image processing processor. The higher the frequency of the video card processor and the more memory the video card has, the cooler (later released) games you can play on your computer.

Sound card

Sound card – designed to prepare sound signals reproduced by speakers. The sound card is usually built into the motherboard, but it can also be structurally separated and connected via a bus.

LAN card

Network card is a board, device, installed on the motherboard or built into it. A network card is used to connect a computer to other computers via a local network or to connect to the Internet.

CD/DVD-ROM

CD/DVD-ROM – a device for reading/writing CDs, CDs, DVDs. These devices differ in the speed of reading or writing information, as well as the ability to read/write various media. Nowadays it is difficult to find anything on sale other than omnivorous CD-ROMs. Modern CD-ROMs are capable of reading and writing both CDs and DVDs of various capacities.

Drive

A disk drive is a device designed for reading/writing information on floppy disks. It is rarely installed in modern computers. A card reader is installed in place of disk drives in modern computers.

Card reader

Card reader is a device for reading/writing information on memory cards. Card readers differ in speed characteristics for reading/writing information. Card readers can be built into the system unit or structurally independent, connected to the system unit via a USB port.

Computer ports

Computer ports are connectors on the system unit designed to connect peripheral devices, manipulators and display devices. We won’t talk about the connectors in detail, we’ll just list some of them: USB, VGA, Power connector, COM port, Ethernet port, Standard audio output connector, etc.

power unit

The power supply is the unit that powers all devices inside the computer. Power supplies differ in power. The more powerful the power supply, the more devices you can connect inside the system unit.

Coolers

Coolers are fans designed for air cooling. Typically, coolers are installed inside the power supply, on the processor, or on the video card. An additional cooler can be installed on the system unit to cool the entire unit.

Radiators

Radiators are metal plates installed to remove heat from processors in the system unit. Radiators are usually cooled by coolers, but not always.

Basic PC peripherals:

The main peripheral devices of a computer include a printer and a scanner. A printer is designed to output information from a computer onto paper. Printers can be divided into laser and inkjet.

Laser printers come in color and black and white. Laser printers print using a laser beam. The laser beam bakes the toner onto the paper, which falls from the cartridge onto the paper. Laser printers differ in printing speed, the number of sheets printed per minute. As a rule, laser printers are found in offices, because... They have a high printing speed and the printed sheet is not expensive in terms of cost. Like inkjet printers, laser printers have cartridges. These cartridges are filled with toner (powder).

Scanner

A scanner is a device for scanning documents, photographs and even photo negatives. The most common type of scanner is flatbed. Different scanners have different scanning speeds. Scanners can also be divided by the extension they support when scanning. Some scanners have a special device installed for scanning negatives. The scanner is usually connected to the computer via a USB port.

Multifunctional devices – printer/scanner/copier (copier) in one device. Combines all of the above functions. A distinctive feature of such devices is the ability to use them as a copier, bypassing the computer. Such combined devices can be either inkjet or laser.

Manipulation means:

Keyboard and mouse

The keyboard and mouse are the main means of manipulating and controlling a computer. Also, the means of manipulation include various joysticks, steering wheels with pedals, steering wheels, but they are intended mainly to control the game process. It can be noted here that not all released games can correctly use or even use one or another game controller.

“Information processes” - In an industrial society, the process of innovation in production plays an important role. Information revolutions. Why does grass appear when spring comes? It is easier to re-create a product than to find an analogue. Currently, the avalanche-like flow of information that pours into a person is no longer perceived in full.

“Computer mouse” - Computer mouse. Painting of computer mice. Wireless mouse. Laser mouse. Mechanical, optical, laser, wireless mice. In a mechanical mouse, the rotating parts become clogged with dust and require periodic cleaning. The A4Tech X5-6AKD wired optical mini mouse is simply ideal for a laptop! Now all PC users cannot imagine working without such a little assistant.

“Windows XP operating system” - We are mobile - we have digital wireless technology! Improved attachment processing. What does selling a computer with Windows XP give? Automatic, timely and free operating system updates! Selling computers becomes easier and faster, because you have everything to show them in action! Business PC.

“Computer structure” - Card readers differ in the speed characteristics of reading/writing information. Typically, coolers are installed inside the power supply, on the processor, or on the video card. Card reader is a device for reading/writing information on memory cards. Laser printers differ in printing speed, the number of sheets printed per minute.

"Measurement of information" - Information. Alphabetical approach. A 256-character alphabet is used to represent text on a computer. Information. Information for a person is knowledge. Possible events. The event that happened. Approaches to measuring information. Measuring information. Properties of information. Probabilistic approach. Alphabet is a set of symbols used to write text.

“Information output devices” - Computer device. Disadvantages of inkjet printers: High ink consumption; High cost of refilling. Monitor. Laser printers. Image quality is determined by the resolution of the monitor. Information output devices. The monitor is a universal information output device. Information on the monitor screen is formed from individual points - pixels.

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