Brief characteristics of the internal devices of the computer. The internal structure of a computer

Hello everyone. Osipov Alexander is in touch. Today we will talk about the main components of a personal computer.

The device of the computer for the entire time of their existence has practically not undergone any changes. We all also hide the main components of the computer in the case. Only the computer components themselves change, but not their purpose. They are becoming more technologically advanced, more reliable, more spacious and faster. New types of connectors for devices and methods of connecting them are invented and pretended to be.

In this article I will tell you and clearly show you the device of a modern computer. Although the topic is rather hackneyed, to say the least, I also really wanted to speak out on this topic, since many people do not know, or have an erroneous idea of ​​what a system unit, processor, video card, etc.

Some people call the system unit a processor, others confuse a hard drive with RAM. This ignorance is very successfully used by unscrupulous sellers of computer stores. After all, if you cannot distinguish one computer device, it is easy to deceive you from another. So first we will conduct a small computer educational program.

A computer system unit is a computer case with components installed inside it, and nothing else. I say this to those who call the system unit of a computer a processor or something else.

Outwardly, many devices are indistinguishable despite their different performance characteristics (RAM, processor, hard drive, etc.). They can differ significantly, both in price and in performance. Look very carefully in the warranty card what you buy, how much it costs and always compare with what is installed in the computer you are purchasing (ask the manager to display the characteristics of the computer's internal devices on the monitor).

To understand whether you are being deceived or not, you need to learn how to understand and choose the right computer devices and components that you need.

Let's move on to a brief description of the necessary computer devices for its full-fledged operation.

(in computer slang it can be called a system unit, a case) - a device whose main purpose is to protect the main components of a computer from external influences and mechanical damage, it is most convenient to place and maintain the required temperature for their uninterrupted and long-term operation.

It also allows shielding electromagnetic radiation.

There are many modifications of computer cases, differing in size and material of manufacture. You can read more about computer cases in the article.

Motherboard (system) board

(motherboard, mainboard, MB, slang for mother, mother, motherboard). It is also called the motherboard, since it is she who unites and organizes the work of all the nodes of the computer. It is into it that we insert the central processor, RAM, video card. Its connectors connect hard drives, optical drives and various peripheral devices.

To control and monitor the operation of all devices, the motherboard provides many different chipsets, microcircuits and controllers.

The choice of the motherboard model determines which type and from which manufacturer (Intel, AMD) the processor will be in your computer.

Also, when choosing a motherboard, pay attention to the type of memory used in it (DDR2, DDR3) and the type of connector (AGP, PCI-E) for a video card (if necessary).

If you buy additional devices that connect inside the system unit (sound card, video card, modem, TV tuner), then carefully see if you have free spaces for them and if the connectors on the motherboard are suitable for the equipment you have chosen.

When upgrading or buying a new computer, first of all, decide on the type and model of the processor, then select the motherboard for it and only then the other necessary devices suitable for your motherboard.

Central CPU

(CPU from English central processing unit, CPU, CPU central processing unit). It is an integrated circuit that executes machine instructions. The main piece of computer hardware. It is the processor that processes the lion's share of the data with which We load the computer.

The performance of the computer as a whole depends very much on the speed of the central processor.

Today, CPU performance is determined by the clock speed and the number of cores. There are other processor parameters that affect its performance, but I will describe them in a separate article.

There are now two major manufacturers leading the microprocessor market for both desktop and laptop computers. These are Intel and AMD corporations.

RAM

RAM(Random Access Memory; in computer slang - memory, RAM).

It is a non-volatile chipset that temporarily stores data and commands that are sequentially used by the central processor to perform specified operations.
Usually, RAM contains the necessary data for the operation of the operating system and the running processes of various programs.

The volume and speed of RAM depends on the number of tasks that a computer can simultaneously perform and the speed of their execution.

Hard disk (hard drive, HDD)

HDD or a hard disk drive (HDD from hard disk drive, hard drive) is a random access storage device based on the principle of magnetic data recording.

Today, it is the primary storage device on all desktop computers and many laptop models.

This segment of the market remained motionless for a long time. Only the amount of stored information on the hard disk grew, but not the speed of its operation.

Nowadays, SSDs (solid-state drives) hard drives based on flash memory are replacing the HDD. Their speed of work is several times higher, but the price still bites.

Hard drive capacity is measured in Gigabytes or Terabytes.

The larger the hard disk, the more you can store various data on your computer.

The hard disk drive is the bottleneck in the speed of a modern computer.

Video card (graphics accelerator)

(graphics accelerator, video accelerator, video adapter, graphics card or card) is a special electronic device that processes and converts the incoming data for further display on the monitor screen.

All modern video cards have their own graphics processor (it allows you to seriously unload the central processor), which, depending on the architecture, is capable of processing graphic information in 2D or 3D modes at one speed or another.

Video cards are divided into external(faster) and embedded(as a separate chip) to the motherboard (slower).

For modern 3D games, a sufficiently powerful external video card is required, and for working in office applications, watching movies or simple games, the built-in video adapter is enough.
Recently, processors with an integrated graphics core have begun to appear. What this gives, I will tell you in one of the articles.

Optical drive (CD, DVD-RW)

- a mechanical device controlled by an electronic circuit and designed to read, write or erase information using a laser of various lengths from optical media (CD) such as: CD, CD-R, CD-RW, DVD, DVD-R, DVD-RW, BD-R, BD-RW.
It can work with both single and multi-layer 12cm or 8cm discs.

Computer power supply (PSU)

Computer power supply (PSU) Is a very important element of a computer system. It is responsible for the stability and quality of power supplied to your other devices in the system unit.
The reliability and safety of information on hard drives, as well as the continued existence of other components, in the event of a power failure in the network, depends on its quality.

Since the network uses alternating current, and the computer requires constant current, the main task of the power supply unit is its transformation (rectification).

The main characteristics of the power supply are:

• Power (measured in watts)

• Efficiency (Coefficient of Performance)

• Built-in surge protection systems

• Cooling

• Dimensions (edit)

Also, when choosing a computer power supply, you should pay to the name of the manufacturer. Brand or non-name.

Here you choose, as they say, "wallet", but the right choice is obvious.

(audio card, "sound card", sound card) - additional or built-in equipment that allows you to reproduce sound using acoustic systems (speakers), as well as to process and record it using special software.

At the time of the advent of multimedia computers, sound cards were separate expansion cards inserted into a special slot.

Modern sound cards exist both external and built into the motherboard.
External audio cards are a much more functional device for processing and outputting high-quality sound compared to built-in sound cards.

Floppy disk drive (FDD)

It makes no sense to consider a floppy disk drive for reading soft magnetic disks, since it is outdated, although many still use it.

Flash drives came to replace him, and in place of FDD, other necessary devices can be inserted into the computer case, such as a Card reader (a device for reading various memory cards) or something else.
There are devices on sale that combine FDD and Card reader. There are also USB floppy drives.

Cooling system

A high-quality and properly organized cooling system for the "hottest" components and the system unit as a whole will prevent many glitches and breakdowns of your computer. From the article you will learn about all the intricacies and nuances of such an important element used in the construction of cooling systems as a computer fan.

I hope this article will help you in solving the issues and tasks that you face.

For each of the devices described here, there will be a separate article with a detailed analysis of all the nuances. From correct purchase to installation in a computer and setup. Goodbye everyone.

Computers are one of the most common means of obtaining information and earning money from the population. In this article, you can get acquainted with the device of most PCs that you can meet in everyday life, unless you are an expert in the field of computer technology.

Why is it needed

First, let's define the term. PC is a personal computer that you see every day when you come to your workplace.

Few of the people working at the computer have an idea of ​​how it works. Meanwhile, knowledge of even the simplest elements can save a person a lot of time in the event of a breakdown. If he knows the device of the PC, at the slightest problem he is able to quickly determine and fix its cause on his own, without waiting for professionals.

This review article will consider all PC devices that a user may encounter, as well as the simplest schemes of interactions between the elements of your computer.

First meeting

Think back to the first time you saw a computer. If you were then asked about what it consists of, at most, what would you be able to answer? Surely this is the common main device of a PC:

• system unit;
• monitor;
• mouse;
• keyboard.

Understandably, any system administrator would laugh at the user for such a response. Meanwhile, you are not far from the truth. With the exception of the system unit, these items are PC peripherals designed to interact with the end user, that is, with you.

The most curious from early childhood try to disassemble the system unit to see what's inside. Those who succeed in doing this, hardly could immediately say without preparation what was in front of their eyes. A lot of microcircuits and wires, the purpose of which we will talk about below.

The internals of a PC are the lifeblood of your personal computer. In general terms, we can say that its insides consist of data transmission and processing devices. This is the so-called technical device of the PC.

External devices

A separate group is the equipment that a person sees in front of him every day. External PC devices are allocated to work and interact with the user.

• Input Devices is hardware designed to enter information and data into a computer.

1. Mouse.
2. Keyboard.
3. Scanner.
4. Joystick.
5. Microphone.

• Output devices are PC devices that show and display information to the user in any form.

1. Monitor.
2. Speakers, headphones, or other audio devices on your PC.
3. A printer.

The further logic is quite simple to follow, so we will not list absolutely all the peripheral devices of the PC. In most cases, external ones are quite simple to replace. If they break, either the computer stops recognizing them, or they simply stop working. Accordingly, it is not difficult to determine which technical device of the PC has failed.

Let's take a look inside

At first glance, the internal elements are too complex, but even their combination has a strict structure. At the heart of everything is the motherboard, which ties together all the devices in your PC. The connection diagram will be considered a little later, but for now let's look under the cover of the system unit and list what we saw:

• motherboard;
• RAM;
• CPU;
• video card;
• sound card;
• HDD;
• power unit;
• disc reader;
• cooling system;
• network card or built-in Wi-Fi adapter.

In addition to the devices themselves, in the system unit you can see a large number of connecting cables, thanks to which PC devices interact, as well as power cables, thanks to which all elements are powered. As you can see, there are a lot of internal components, so it makes no sense to consider them together, and we will describe them separately.

"Brain"

In general, "brains" in the slang of programmers is the central processor of a personal computer. It is used to process all data and signals, as well as to process the processes stored in the PC memory. It looks like a small plate with many pins-connectors, placed on the motherboard, usually completely covered on top by its own cooling system - a cooler (fan).

The development of technology does not stand still, and processors are becoming more powerful every year. Back in 1995, a 350 MHz processor could be considered the ultimate dream of an ordinary user. This was enough for all computer tasks. Today, CPUs have several cores - 2, 4, 8, each with capacities up to several gigahertz.

However, nothing revolutionary has happened in this area over the past decades. Capacities are growing slowly, and no breakthroughs are expected in the field of information processing speed.

Memory

Some users believe that computer memory is how much information it can hold, and this is partly true. The memory device of a PC can be divided into two types, just like that of a person. There is long term and short term memory.

PC RAM is a short-term memory that contains all the data and processes when you are working on your computer. When you run any program, its working part is transferred to RAM. It is from there that the data is transferred to the microprocessor for processing. The volume of the OP determines how much information can be contained in it, and the speed of its processing.

From the point of view of its development, no particular breakthrough was noticed either. The volumes are growing by one level, the speed of processing and transmitting information to the microprocessor, but nothing grandiose is foreseen.

A hard disk is a permanent, long-term memory of a computer, with which the user directly works. This is where you write your information, programs and games. The size of the hard disk memory is much larger than the RAM.

Volatile memory is located on the motherboard. Serves for storing the most general and basic settings of a personal computer, such as date, time, passwords, information about the system boot. This memory got its name from the fact that it needs constant replenishment of energy, which it receives through a battery located also on the motherboard.

It is also worth noting that memory is part of PC devices, since it contains information on processor requests.

Nutrition

A thesis that any student can understand: all PC devices consume electricity. A failure in the computer's power supply leads to the loss of data from the RAM and volatile memory, and if the computer turns off while the user is working, not only unsaved data may disappear, but existing information may also be damaged, which may lead to unreadable files.

With the help of power cables, the unit supplies voltage of +12 and -12 volts, as well as +4 and -4 volts to personal computer devices, so you are not in danger of death from electric shock. However, it is better not to take risks and follow safety precautions.

Picture and sound

To display the image on the screen, a video card is used, also mounted on the motherboard. In many cases, there are built-in video cards on the "motherboard", but they are too low-powered to work with graphics programs or games. Therefore, people usually purchase more efficient components in a complete set.

Graphics cards in a computer are one of the hardest parts to work with. Based on this, experienced system administrators install additional cooling inside the system unit in addition to what is already there.

The best video cards have several ports - for connecting not only a monitor, but also a TV.

An integral part of the image is sound. The personal computer also has built-in sound cards. They provide a fairly high-quality sound, however, for fans of special effects, the purchase of additional elements is also recommended.

Sometimes you may have noticed that the PC is making high pitched sounds when booting up. They are produced by a built-in speaker, which, depending on the BIOS manufacturer, informs the programmer about the loading status with sound signals. In older games, this speaker was also sometimes used to create ambiance.

The foundation

The article has already mentioned the motherboard more than once. It is the heart of the computer, linking all of its parts together in a single-piece microcircuit. It serves to provide absolutely all devices of a personal computer.

Physically, this is a board on which all internal expansion strips are attached, as well as components located inside the system unit. This is the main device of the PC.

The logical structure of the motherboard is divided into north and south bridges. Although many companies are beginning to abandon the implementation of the former, transferring its functions to the central processor.

Let's figure out what is called the north bridge. This is a part of the logic diagram of a personal computer, designed to ensure the interaction of internal devices and the south bridge. The latter is the part of the circuit that is responsible for the interaction of I / O devices.

The motherboard contains slots for expansion cards, ports for connecting external devices, as well as one of the most important parts of a personal computer - BIOS. He is responsible for the fundamental settings of the computer, loading the operating system, as well as the possible setting of some of the physical parameters of the PC.

Assembly

PC devices are connected directly to the motherboard. For internal elements, there are special wires - loops, consisting of several small wires, each of which carries a specific function. Also, all internal devices are connected to the power supply with power wires. A small tip: when connecting expansion cards, it is better to support the motherboard from the back side, however, due to the fact that it is attached to the case of the system unit, you can use a pencil, carefully slipping it under the microcircuit.

External devices are connected to the part of the motherboard that is open on the back of your personal computer - the so-called ports. In the past, each external device had its own dedicated connector, but over time, developers have come to a single standard for connecting wires. And now USB ports are used to connect external devices. The table above shows some of the older port names.

Remember that almost any device connected to your personal computer requires installed drivers to work.

Security

Many are skeptical about some safety requirements when working with a personal computer, but its effect on the human body is not fully understood, so it is better to follow them.

• If you are going to work with your computer and, moreover, disassemble it, be sure to dry your hands dry.
• Before touching the motherboards with bare hands, be sure to discharge static electricity by touching the PC case.
• Work at a personal computer with breaks, at least 2 hours.
• Ventilate the room regularly.
• Clean the computer from dust inside the system unit.

By following these tips, you can extend the life of not only yourself, but also your computer.

Conclusion

Thanks to this article, you were able to gain basic knowledge of the structure of your personal computer. This should help you in solving a number of problems related to the repair and purchase of PCs, as well as the organization of your workplace or the place of your employees. And it will also help protect yourself from unnecessary spending on spare parts with proper and timely care of your computer.

With all this, having raised the level of your erudition, you will be able to communicate with your friends on computer topics and not look stupid in dialogues.

If you have not read it, then I recommend that you familiarize yourself before reading this article. Today we will climb into the "holy of holies": system unit or " systemist"In everyday life. To make it clear, I disassembled my own system unit and took photos, which I will provide you as a visual aid, let's say, system unit device in pictures... Let's start with internal device of the system unit, and then we move on to the outside. Let's get started!

To begin with, it is worth making a reservation that the system unit in shape can be horizontal (called Desktop), which is usually located under the monitor, or vertical, called Tower (from English "tower"). The tower case, depending on the size, can be big, midi and mini. The most common case is the mini tower, you can see it in the photos. By the way, you can familiarize yourself with the structure of the system unit of your personal computer, but you need to be very, very careful and first completely disconnect the computer, and only then start doing something. It is advisable to disconnect all the wires, but if there are problems with their connection, then it’s better not. We will talk about connecting devices to the system unit in a series of articles, having dealt with. If the system unit needs to be removed from under the table, for example, then this must be done very carefully, avoiding shock and shock. In order to see what is in the system unit, I need to remove the side cover by unscrewing 2 screws on the back wall, but the device of the case can be very diverse. The main thing is to carefully examine the case and understand what the cover is attached to. It should be removed effortlessly, so don't be zealous. So, the lid is removed, let's figure out what is needed for what.

Let's start with motherboard, which is also called maternal, and sometimes even affectionately "mother". And no wonder: it is the largest and (as befits a mother) monitors a horde of other devices and coordinates their work, transmits a signal from one to another. It is not difficult to find it, the motherboard, as I said, is large. In the photo, it is highlighted with a green frame and marked with a number (1) in the corner.

The number (2) hides the processor in the system unit. He is really hiding, because in the photo he is not visible at all. However, it looks like this:

CPU Is a specially grown silicon stone, which, moreover, contains an incredible amount of other elements: transistors that are interconnected. The processor is a kind of "brain", because it processes the incoming information. One of its most important characteristics is the clock frequency, which is the number of the simplest (elementary) operations that can be performed per unit of time (second). Measured in MHz (megahertz - that is, millions of hertz) or GHz (gigahertz - billion hertz). A lot, isn't it? Usually you can see these numbers in the description of the complete set of the purchased computer or in the advertisement for the sale. For example 3000 MHz. The most common processors are from Intel and AMD. During operation, the processor heats up, so it is installed radiator, which removes all this heat, and from above is still installed cooler Is a small fan that circulates air and cools the radiator. You can see it under the number (2), and under it you can see the radiator. Let's take another look at a larger photo:

The computer operates with information, so it must be stored somewhere. Let's draw an analogy with a person: there are things that we need only during work, for example, a formula. It is not necessary for us to remember it, and it is impossible to keep everything in our head, so it is written down somewhere in a book or in a notebook. So is the computer: all data is stored on drives, and when some data is needed for work and must be used, it loads them into RAM(RAM - random access memory). She is number (3) in the general photo. It loads because it is faster to work with it, because this memory is very fast. When the computer is turned off, there is nothing in this memory, everything is erased, just like ours, when we sleep - we cannot think at this time. And at this time the information on the computer is only on drives.

Under the designations (7a) and (7b) and highlighted in yellow, just hard drives... The hard drive is also called Winchester, and in everyday life "screw" or "broom". It keeps data on it even when the computer is turned off. They are characterized by many parameters, but you need to keep in mind only the volume, which shows how much data can be written there, and the access speed. However, it is worth getting acquainted with the units of measurement of information in a separate article, for now we will omit this. Let's take a closer look at the hard drive from the inside.

We can also see the cables. Naturally, each device needs electricity, so each has a power cable from the power supply, which will be described a little below. And also you can see such a wide ribbon cable, in the picture it is labeled as "IDE cable". Don't be scared, you just need to know that there is an IDE hard drive and SATA, it depends on how they are connected to the motherboard, we will not go into details, but the latter has a much narrower cable. This cable is used to transmit information.

Thus, we have found out that there is random access memory, into which data is loaded as needed when the computer is running from a drive, where it is stored permanently. However, when the computer turns on, it needs commands, because its RAM is empty! Imagine that you wake up, and your head is empty! To do this, the computer has a read-only memory (ROM). It contains the basic programs that check the state of the system and its readiness for work and make it possible to interact with the monitor, hard disk, keyboard, disk drive. All these programs form basic input-output system (BIOS - Basic Input Output System)... When you turn on the computer, you immediately see the operation of this very basic system: these are those white letters and numbers on a black background.

If you paid attention, even if the computer is turned off for a long time, the date and time remains correct. This is due to another microcircuit. CMOS, in which this data and data about the computer's hardware are stored, the microcircuit willingly transmits this data on demand to the BIOS, after which the computer boots. The motherboard has battery, thanks to which no data is lost in CMOS. It lasts for a couple of years, sometimes you have to change it.

In this figure, you can just see 2 strips of RAM and a free slot for one more. The bar is simply inserted there and clamped on the sides by holders. You can see them in the picture, they are white, and in the general photo they are numbered (3). On the left, under the lower RAM bar, there is a processor heatsink, and a part of the cooler is visible above it.

Let's look further, what's interesting inside the system unit of a personal computer. Here in the next photo you can see this battery, thanks to which the time on the computer runs even if it is turned off. The photo shows the connectors into which you can insert other useful devices.

For example, at the top of this photo you see the network card. In the general photo, she is numbered (5). It is needed in order to be able to connect several computers together so that they can exchange information with each other.

Below you see video card (video adapter), she is in the general photo under the number (4). It is needed in order to form and display the image on the monitor.

Of course, there may not be such a bar, the video card can be built into the motherboard, but if you need a much better image, if you need to play modern games, then of course the capabilities of the built-in video card are not enough. The video card has its own memory, like RAM. And also powerful video cards have their own heatsink and cooler, because these hard workers also heat up great.

One of these free slots could be installed and sound card, however, I have it built into the motherboard. Sound engineers and music lovers, as well as everyone who loves high-quality sound, of course get such a card.

Do not ignore such an important device as power unit... Number (6) in the general diagram and directly in front of you in the next photo.

This massive companion is engaged in the distribution of energy between all devices. The power supply, of course, must be stable, and the unit must be powerful. I have 300 watts, but the computer is pretty old. Now there is more power, because so are the needs. The system unit even has its own cooler. We will see it in the next article, where we will look at the "exterior" of the system unit.

And finally, we still have several devices that also allow us to save information on drives.

CD / DVD drive... Number 9 in the shared photo and close-up right above this text. It allows you to write and read information using a laser onto discs. They will be discussed in more detail in the article on information storage. It also has a power cable and a cable through which information is transmitted. The main characteristic is the speed of data reading.

In some places on the computers there are still oblong slots in the front of the system unit. This is a floppy disk drive (FDD)... Floppy disks are almost never used anywhere due to their small capacity (that is, they hold little information).

So, the blitz-examination of the insides of the computer system unit is over. We close its lid, tighten the screws, it's time to plug everything back and get to work!

So, from this article you learned:

how the system unit is arranged what's inside it

• what they look like and what they are for system unit components

Have you ever opened your system unit? After all, it was interesting for everyone to look at the computer device inside the system unit. What's going on there? There are many small parts (devices) that at first glance will seem very complex and mysterious to you. But in reality, not everything is so complicated. This lesson will help you master some basic concepts, get acquainted with the computer device inside the system unit.

Computer device from the inside (hardware)

Let's take a look at the inside of the system unit.

Central processing unit (CPU)- this device is located inside the system unit, on the motherboard. It is called the brain of a computer, and its job is to execute commands. Every time you press a key, click the mouse, or run a program, you are sending commands to the processor.

Processor speed is measured in megahertz (MHz) - million operations per second, and gigahertz (GHz) - billion operations per second. A faster processor will execute instructions faster. However, the speed of a computer depends a lot on the speed of various components, not just the processor.

There are many manufacturers of processors for personal computers, but the most famous are Intel and AMD.

- This device is the main board of the computer. It is a thin plate that contains the processor, memory, connectors for hard drives and optical drives, expansion cards, as well as ports, USB ports.

It powers the computer. It sends energy through the cable to the motherboard and other components.

If you decide to look inside the system unit, then first of all make sure to unplug the computer from the outlet. Before touching the inside of the computer, you must touch a grounded metal object or a metal part of the computer case to discharge static build-up. Static electricity can be transmitted through computer circuits and destroy them.

RAM - random access memory (RAM) is your system's short-term memory. Whenever the computer performs a calculation, it temporarily stores the data in memory for as long as necessary.

This temporary memory disappears when the computer is turned off. If you are working on a document, spreadsheet, or other type of file, then you must save it so as not to lose it. When you save a file, the data is written to the hard drive, which acts as long-term storage.

RAM is measured in megabytes (MB) or gigabytes (GB). The more RAM, the more processes the computer can run at the same time. If your computer slows down, slows down when there are several open programs, then this is due to a lack of RAM. In such a case, you can always add additional RAM to improve performance.

A bit is the smallest unit of measure. A byte is 8 bits. A megabyte contains about one million bytes, and a gigabyte is about 1 billion bytes.

Is a data center on a computer. All the software, all your documents and other files are installed there. The hard disk serves as long-term storage. This means that even if you turn off your computer and disconnect it from the network, all data will be saved.

Responsible for what you see on the monitor screen. Most computers have a GPU (graphics processing unit) built into the motherboard. In simple words, this is an integrated video card. But if you play games with powerful graphics, then the built-in video cards will simply not be able to reproduce them. Therefore, some people install a separate powerful video card in the additional expansion slots of the computer.

A device called a sound card(the name speaks for itself) is responsible for the sound. Here I think everything is clear.

Network Card Allows a computer to communicate over a network, access the Internet via an Ethernet cable, or over a wireless (Wi-Fi) connection. Many computers have network cards built into the motherboard. If you don't have one, you can buy a network card separately and add it to an additional expansion slot.

It is a short-range wireless communication technology. It is often used in computers to operate wirelessly. keyboard, mouse and printer... They are rarely built into the motherboard.

This book is devoted to the consideration of hardware - as the people call the material component of computers (or Hardware - hardware), in contrast to the software part of the functioning of computers (or Software - software). The standard set of a home personal computer is shown in the figure below.

What does the hardware part of a personal computer consist of? First of all, from the system unit, inside which are located internal devices and external devices connected to the system unit using information cables or establishing communication with it via wireless information channels (using infrared radiation, radio waves, etc.).

TO external devices include those that are outside the system unit. These include: keyboard, mouse, display, there may be other devices: printer, external modem, scanner and other devices.

TO internal devices includes the motherboard (popularly called the motherboard or simply "mother"), the central processor, RAM, power supply, hard drive, previously installed floppy drive, CD-ROM drive and / or DVD drive, sound card, video card, speaker, as well as some other additional devices inserted into the so-called expansion slots - network cards, TV cards, etc. The figure below shows the standard arrangement of internal devices in the system unit.

The motherboard, processor, RAM, video card, sound card, expansion cards, hard drive and speaker are located inside the system unit, are not visible to the user, or rather, do not have an exit to the front panel of the system unit.

Internal devices.

Computer case It is used to install the main devices in it, to protect them from dust and other external influences, and also to some extent protects the user from the electromagnetic radiation of the components that are in it. The front panel contains indicators and buttons; some internal devices (floppy disks, DVD-RW drives) also face out onto it.

Power Supply is designed to convert an alternating electric current with a voltage of 220 volts into a direct current of a lower voltage and supply it to devices located inside the system unit. As a rule, this unit comes with a system unit, but you can buy it separately. The system unit has connectors on the back for connecting to a power source (an electrical outlet or a surge protector), in some models - a connector for connecting power to a 220 volt monitor (if the monitor has a cathode ray tube) and a switch for different input voltages - 110 or 220 volt. Inside the system case there are wires that exit the power supply and connect to internal devices.

Motherboard serves to interconnect information flows between various computer components. It has a central processor, RAM, a Bios chip, in some cases - its own fan for cooling the central processor, as well as various connectors (for connecting fans external to the board, connecting serial and parallel ports, expansion cards, and so on). In addition, in recent years, built-in network, audio and video subsystems, as well as their own speaker, a buzzer, have begun to be mounted on the motherboard.

CPU. The processor, which can be called the brain of a computer, performs basic operations. Processors can be: 86, 286, 386, 486 (x86 series), Pentium, Pentium ММХ, Pentium Pro, Pentium II, Pentium III, Pentium IV, Atom, Pentium Dual 2 Core, Pentium i 3, Pentium i 5, Pentium i 7 - manufactured by Intel, as well as other companies, for example, AMD - Athlon XP, Athlon 64, etc. The difference between them is in performance. The higher the clock frequency of the processor, the higher the performance of your computer (although not always, for example, the performance is affected by the amount of cache memory of the first and second levels, as well as the structure of information processing, for example, the emulation technology of the second processor Hyper-Threading). The presence of cores also affects performance; a dual or triple core processor is much faster than a single core processor.

The clock speed determines how many operations per second the processor can perform. For earlier types of processors (for example, 286) one instruction was executed in several cycles. In modern ones, several operations are performed in one clock cycle.

RAM... After turning on the computer, the data from the hard disk is transferred to the RAM, and the processor works with them. If it were not for this type of memory, the processor would work only with the hard disk and each data would have to be written to and read from it. At the same time, the speed of work would be sharply reduced, since the system would be waiting for I / O operations. If you have RAM, which works at a speed close to the speed of data processing by the processor, the performance of the computer increases. The larger the memory, the fewer disk accesses, and the faster the computer will run.

The main characteristic of memory is its size, which is measured in gigabytes. Can be installed 0.5, 1, 2, 3, 4, etc. gigabytes on the system. It is often cheaper to increase the size of the RAM to improve performance than to upgrade the processor to a higher frequency.

In order to speed up calculations and not wait for data to come from RAM or it is necessary to write data to it, the processor has a more efficient cache memory, which differs in volume. The presence of cache memory can significantly increase the performance of your computer.

The system unit also contains speaker which is usually supplied with the case. The main function of the speaker is to give sound signals after turning on the computer and in the event of a malfunction. As a rule, in other cases it is used quite rarely. A sound card is designed to work with sound.

Sound card. This board processes audio data that comes from RAM. Data can also come from a DVD-ROM disc reader when playing music. After processing, the data is sent to speakers, a tape recorder, or other devices.

Video card processes data for the display (monitor). For programs that work with 2D or 3D images, the processing of video data for the display can be taken over by a special processor located on the video card, which will offload the main processor. The image quality is usually increased dramatically.

One of the main characteristics is the video memory size of the board. It can have 1, 2, 4, 8…. 64, 128, 256 512 1024 and more megabytes (usually 0.5 - 1 Gigabyte). The more memory there is, the faster the data processing takes place.

HDD. The data in the computer is stored on the hard disk. When the power is turned off, the information on the hard disk is retained. One of the main parameters is the disk capacity, which is measured in gigabytes (One gigabyte equals approximately one billion bytes. A byte stores one character). The disk can have a capacity of 8 gigabytes to 4 terabytes (1 terabyte is equal to 1024 gigabytes). Older drives have capacities measured in megabytes (one megabyte equals approximately one million bytes).

Now let's look at the devices that come out on the front surface of the system unit (see the figure below).

Floppy disks. The front panel of the computer case, usually on older computers, has a 3.5-inch floppy disk drive facing out (picture on the right). 5 1/4 "floppy disks have long been out of use and will practically not be considered by us, although many of the principles of their operation are the same as for 3.5" ones. Note that in modern computers, 3.5-inch drives have long been abandoned due to the insignificant amount of recorded information.

A 3.5-inch floppy disk (hereinafter simply a floppy disk, floppy disk) has the appearance shown in the figure above. Data written by the user on a floppy disk can be moved from one computer to another, since almost any computer previously had the same device for reading from a floppy disk.

.

A conventional view of the drive is shown in the figure above. Taking a floppy disk, insert it into the floppy disk hole until it stops so that the metal plate is in front, and the arrow on the floppy disk case is on top, and its point is directed towards the inside of the device. After that, the protective cover of the reader will snap into its original place. To remove the floppy disk, you must press the button located on the front panel of the drive. This will cause the floppy disk to come out of the device about 1/3 of its length, after which it can be removed by hand.

In the figure, the left corner of the floppy disk is beveled. This is so that the system can determine which side of the floppy disk is inserted. If you try to insert a floppy disk upside down, the disk will not be inserted into the device. In this case, you do not need to use force, but turn the floppy disk over.

The floppy disk has two windows. There is a switch on the right window on the back side. If the switch closes the window, then information can be written to and read onto the floppy disk. If the latch is open, then the data can only be read. Typically, the switch is used so that when storing important data, other information is not accidentally written on them, which will lead to their destruction, or as a protection against viruses.

The figure above shows the front panel of a floppy drive. The button is used, as already indicated, to remove the floppy disk. The indicator turns on when the diskette is being I / O, that is, data is being written to or read from the diskette.

Drive forCD (DVD) - disks works with CD, DVD discs of different types. The appearance of these discs, also called CDs, is the same and is shown in the figure to the right. CD-ROM (DVD-ROM) discs are manufactured industrially and it is impossible to record additional information on them. CD-R (DVD-R, DVD + R) discs allow you to write information on them, but only once, although you can add information if there is free space on the disc. CD-RW (DVD-RW, DVD + RW) discs allow not only recording information on them, but also erasing the previous one, which allows them to be used repeatedly.

After placing the disc in the tray, press the button again to eject the tray and the tray will enter the device. CD (DVD) - discs are usually in a box or in a paper bag. Open the box. To remove a disc, move your index finger to the center of the disc and remove it with your thumb and middle fingers, then place it on the tray with the working surface down, respectively, the name will be at the top. In order to insert a CD (DVD) -disk, it is necessary to press the button on the front panel of the drive while the computer is running (see the figure above). This will automatically pop out the tray on which you can place the disc. There are two indentations in the tray as there are two disc sizes. One of them, a smaller one, is rarely used, although it is sometimes shown in science fiction films. Discs of this format fit into a smaller depression. The disc of the second type, the most common, is placed in a large recess, with the working surface down and the painted image on top. After placing the disc in the tray, press the button again to eject the tray and the tray will enter the device.

Sometimes when you press the button, the tray stays in place. In order to pull out the tray, you can use the hole for forced opening of the tray. To do this, unfold a paperclip, insert its end into this hole and press a little. The tray will come out of the drive.

On the back of the disc is its name or other information. The opposite side is working and it is undesirable to touch it with your hands. When cleaning CD (DVD) -discs from dust with a cloth, gently pass perpendicular to the recording tracks from the inner hole to the outer edge.

There are two types of CD (DVD) discs. The first is discs with textual, graphic and other information, as a rule, with programs or text. The second type is music discs used in laser audio players and can also be used to play CD (DVD) discs (hereinafter CD devices) on a computer. In this case, the sound can be listened to through headphones or from speakers. The headphone plug is inserted into a special hole on the front surface of the drive. To increase / decrease the volume of the headphones, use the control located near the hole for the plug. The indicator light works when reading information from the disk. Since the reading occurs in jumps, the indicator may blink.

The appearance of DVD-drives is similar to a CD-ROM drive. The front panel of the CD-RW drive is shown in the figure above.

Buttons on the system unit... In addition to the above devices, on the front panel of the system unit, as a rule, there are Reset, Power keys, as shown in the figure above, on obsolete units there may be - a Turbo key, a lock for a key and an indicator. Recently, there has been a transition to the ATX standard, in which there is no key lock, Turbo button and system frequency indicator. Thus, on a modern system (and in a candy bar), as a rule, there is only a power button and, often, an indicator of the operation of hard drives.

Power button is designed to turn on the computer. When pressed, an electric current is supplied to the main components inside the system unit, they are tested and then the operating system programs are loaded, depending on which one is installed on the computer: UNIX or Windows 9x. In older computers, this button was located on the back of the system case, then on the side, but for ten years it has been installed on the front panel. The switch is usually labeled as Power or On and Off. In order to turn off the computer, usually when you exit the operating system by pressing the button Completion of work from the Start panel, the computer automatically shuts down. However, in some cases, for example, when the system freezes, it is required to shut down the computer forcibly. To do this, press the Power button and hold it down for a few seconds.

Reset button(on older computers) is used to restart the computer. When you press it, the operating system is rebooted, just like when you turn on the computer at the very beginning of work.

When is this button used? System crashes occur from time to time. The more complex and unsettled the program, the more errors it contains. Over time, with the release of more modern and, accordingly, more debugged versions, the number of errors decreases, but it is impossible to completely get rid of them due to the complexity of the programs. There are even standards for bugs in large systems.

They say that the computer "freezes" when the system does not respond to pressing keys on the keyboard, or the program starts to display incomprehensible characters, or when you press one key, an action occurs that is typical of pressing another. In this case, it is advisable to restart the computer. However, if you turn off the power of the computer, and then press the Power key, thus turning on the computer, then all systems experience a kind of shock. With a large number of on and off switches, the likelihood of failure of microcircuits increases (the same principle as when the light bulb is turned on). For these cases, a Reset key is provided, which allows you to restart the computer without disconnecting the electric current.

If you nevertheless decide to turn off and turn on the computer using the Power key, then wait 40-50 seconds between turning off and on. This will lengthen the life of your system. In addition to errors in the software, computer freezing can occur due to the actions of virus programs. In this case, it is advisable to reboot from the system floppy disk.

Not all system blocks have a Reset button. In some units, the Reset button may be located inside the Power button (its fixed part) or near it.

Turbo key currently in practice. If you have it, then it is best to turn it on (that is, a larger number or the word High will appear on the indicator) and not touch it again. This key appeared in the computer when, with the advent of faster processors, there was a need to decrease the power so that old programs could run. Nowadays, programs themselves determine the performance of the computer and can slow down the computer (this is mainly used in gaming programs), so the Turbo key is not used.

Indicators... As a rule, they are of four types on a computer.

Frequency indicator(in old computers) the operation of the processor is indicated on the display by the numerical value of the frequency. These values ​​can be numeric or text. There are usually two numerical values, the first is the clock speed of your processor, the second is the reduced frequency of its operation. There are also two text values: High (increased) and Low (low), which means the processor is operating at a normal (High) or low (Low) frequency. If your computer was modified or was purchased from a company where the computer was assembled there, then the indicator may show a different value than the processor actually works. In order to determine the frequency of the processor, it is better to use test programs. When working with a computer, the indicator is now practically not used. This indicator is not used on modern computers.

Hard disk drive indicator lights up during I / O operations to the hard disk. There may be an icon next to it. .

Power On Indicator lights up when the computer is turned on. Next to the indicator is the name Power or an icon.

Turbo indicator(in old computers) lights up in Turbo mode, that is, increased power or that for which the central processor is designed. Next to it there is an inscription Turbo or an icon ... When working in modern computers, it is practically not used.

Additionally, there may be USB and audio in and audio out connectors on the front panel or to the side of it.

External devices .

In addition to the system unit, the personal computer includes display(also called monitor), which displays text and graphic information. Outwardly, it resembles a TV, as can be seen from the picture earlier. There are two types of monitors: color and monochrome (black and white, is practically not used anymore). The main characteristics are frequency displaying lines on the screen (the larger it is, the better for the eyes), permission, which can be 480x640, 600x800, 768x1024, etc. (the larger this value, the better), diagonal screen size in inches(maybe 14, 15, 17, 19 and others).

The next component is keyboard(figure below), with the help of which text information is entered and the computer is controlled using the function keys. In fact, it is very similar to a typewriter, but it has additional keys and, in addition, allows you to work with different character sets, for example, with the Cyrillic (Russian) and Latin (English) set.

Next to the keyboard is a device of the type mouse, which allows you to control the cursor (figure on the right). It has become a standard pointing device, it is used in almost all computers and outwardly really looks like a mouse - a small one with a long tail, that is, a cable that connects to the system unit. Hereinafter, for convenience, we will refer to this device simply as a mouse or mouse.

At the bottom of the device is a ball (or LED device) that allows you to move the cursor on the display screen when you move the mouse across the mat. You can try working without a mat, but since the grip between the mat and the mouse ball is higher than on the table surface, it is better to have a mat, especially since it is inexpensive. The mouse has two or three buttons, but in practice two of them are used: left and right. In the latest models of the mouse, instead of the third button, there is a wheel that allows you to "scroll" the text displayed on the screen.

Computers often have a paper output device called printer... The main characteristics of the printer are its type (needle, inkjet, laser), the size of the paper with which it works (A4, A3, etc.), the ability to output an image in color, the output speed of printed sheets, etc.

A computer that can handle sound has columns to play audio information. As a rule, there are two of them to ensure stereo sound. Columns can be embedded display.

In addition, in addition to the personal computer, other external devices can be included - scanner (picture below) , plotter, joystick, external hard disk and others. However, the specified configuration is basic, sufficient to run standard sets of programs called packages, such as Microsoft Office and solve some applied tasks, in particular, Multimedia- work with sound and images.

The computer has means of input, output, information processing and a device that controls the operation of computer components. To typical devices input information include keyboard, with which characters are entered and commands are given for the functioning of the computer, mouse, scanner, microphone, digital video camera and camera other. To typical devices withdrawal information include display, on the screen of which visual information is displayed, a printer, sound speakers etc.

There are also I / O devices that not only introduce information but and take her out: floppy drives , drives on CD and DVD - disks , hard drives , tape recorders (or more correctly - streamers ), modems etc.