Internal components of a computer. The main components of a computer. Personal computer device

Today, computer technology is advancing by leaps and bounds, and, for example, a PC can become completely obsolete in a few years. And on outdated hardware, many modern programs will run slowly or not start at all. Someone will offer to buy and someone will offer to upgrade. In both cases, you need to know the structure of the computer system unit.

General information

What are the main parts of your PC? In general, the structure of a computer requires the presence of the following elements:

• Internal devices of the system unit.
• (usually a keyboard and mouse, but can be supplemented with many others, for example, a drawing tablet).
• Information output devices (monitor, headphones).
• Additional (card readers, TV tuners, network adapters, USB modems).

The structure of the computer system unit must be considered in detail, because it includes many important components that directly or indirectly affect the performance of the system as a whole. These components include:

• Motherboard.
• CPU.
• RAM.
• Hard drive or solid state drive.
• Video card.
• Sound card.
• PCI devices.

Computer processor structure

It is believed that the central processing unit is the most complex digital device in a computer. It is made in the form of a silicon wafer in a housing with many pins that connect to a special socket on the motherboard. A substance is sprayed onto the silicon, reproducing a complex but very small electrical circuit.

Several million elements (transistors, resistors) are included in the structure of a computer processor. All parts are several nanometers in size. After manufacturing the device, a radiator is installed on it to remove heat and a blowing fan. When a large number of transistors operate simultaneously, this cannot be avoided.

The structure of a computer processor is so high-tech that only two companies in the world compete in this market segment (Intel and AMD).

Main characteristics of the CPU

The main characteristics of the CPU are the cache size and the number of cores. Accordingly, the higher these parameters, the faster the device performs calculations. The clock frequency determines how many logical and arithmetic operations can be performed per second by one core; accordingly, if there are two cores in the computer, then twice as many operations are performed per second.

The cache is designed to store commands that programs send to the central processor. Information is exchanged with the cache at the highest speed. If its size is too small, then it will not be possible to use the full speed of the processor.

Motherboard structure

Of course, it is necessary to consider the structure of the computer motherboard. The motherboard is a complex device with multi-layer circuitry. It contains the main sockets for connecting all other computer devices, logic sets so that all components work interconnectedly, and controllers for the main interfaces (sound card, input/output devices). Often, the motherboard may have slots for additional devices (PSI-e, PCI, USB).

The key component of a motherboard is the chipset. This is a chip that connects device controllers to the CPU for their joint functioning. The internal structure of the computer is entirely determined by the chipset. For example, it is impossible to install third-generation memory into a motherboard if the logic only supports the second, and this also applies to all other devices.

RAM

RAM (random access memory). When describing the internal structure of a computer, this element cannot be ignored. RAM stores temporary data and processor instructions for which there is not enough space in the cache. The most important memory characteristics are frequency, capacity, generation and timings. At the same time, a memory stick of the DDR2 or DDR generation cannot be installed in the DDR3 slot, because the sets of software logic for all these generations are different.

Frequency and timings are the most important indicators for determining the speed of information exchange with RAM. There are two mutually inverse rules here. If the frequency is higher, the speed is higher. The opposite law applies to timings, so lower ones are preferable.

Video card

The structure of a personal computer in the modern world necessarily requires the presence of a video card. In simple terms, this device prepares and generates graphic information, which is subsequently displayed on the screen.

The video adapter can be built into the computer's motherboard or connected to a PCI-e connector. Adapters of the first type are almost always called budget adapters; they allow you to work comfortably in office software packages, but do not create complex three-dimensional images. Even if such video cards are capable of outputting graphics, it is unlikely that their power will be enough to reliably maintain an acceptable level of FPS (frames per second).

If we consider a video adapter connected to the PSI-e connector, we can say that this is an additional computer installed inside the system unit. Its structure also includes a processor (but not a CPU, but a GPU) with a cooling system, video memory (GDDR), controller, DAC and ADC (digital-to-analog and analog-to-digital converters).

The fact that the computer structure includes such a complex apparatus is due to the increased resource requirements for rendering realistic three-dimensional graphics. Otherwise, you will have to forget about the beauty of modern video games.

You can study the main characteristics of a video card based on the most important parameters of the remaining components included in the structure of the computer. Here you need to include the frequency of the video processor, the volume, frequency and bandwidth of video memory. We can't help but mention SLI and CrossFire technologies. They allow you to combine several video adapters to increase the power of the video system.

HDD

Hard Disk Drive is used to store data. It is on it that the OS, games, programs are installed, and it is on it that music, videos, and photographs are stored. The structure of the computer is such that any device can be replaced with a similar one without problems, however, after changing the HDD, all user data is lost, because the highest reliability requirements are imposed on devices of this type.

Main characteristics of HDD

Capacity (measured in bytes), the larger this number, the more data can be written to the drive. In modern conditions, it makes sense to give preference only to those members of the family whose capacity is above 500 Gigabytes.

Spindle speed (measured in revolutions per second) determines the average speed of data access. The higher this characteristic, the faster the information is read and written. Remember that high speeds create high noise levels.

Interface (type of connector for connecting to the system board). The structure of a personal computer in the modern world is such that it is almost impossible to choose a motherboard and a hard drive so that they do not suit each other.

A cache is similar to RAM. Its purpose is to smooth out the difference between read and write speeds. When choosing a device, this parameter can be ignored.

Keyboard

Everything is moving forward, everything is developing, the computing power of processors is increasing, teaching aids and lectures on which computer science is taught are changing. The computer structure, however, has one component that remains unchanged - the keyboard. It can be with membrane keys, semi-mechanical, mechanical or use a scissor mechanism.

The membrane mechanism structure includes plastic cones and three layers of film on which the contacts are located. When you press a key, the cone contracts, shorting the upper and lower contacts. These keyboards are the cheapest and lightest.

In semi-mechanical keyboards, instead of short-lived sprayed contacts, metal ones are installed, which are attached to the But the return of the key to its original position and the closure of the contacts is still performed by a plastic cone.

Mechanical keyboards use a spring as a return mechanism. They are considered the most durable and reliable. Their service life in normal mode ranges from 50 to 100 years. The weight is much higher than any others.

They are considered a type of membrane. These are most often installed in laptops. Under the key, in addition to the membrane, there are two cross rectangular bars that ensure smooth movement, and this in turn protects against jamming.

power unit

When computer anatomy (or the structure of a computer) is described, information about that component is often crossed out. But in vain, the stability of the entire system depends on the power supply.

Its main characteristic is power. The modern market offers a choice of devices from 300 to 1600 Watts. Four hundred is enough for an office computer, but the latest gaming system will require at least a kilowatt.

Keep in mind that the power supply must not only provide all components with the necessary power, but also have excess power exceeding the standard indicators by 20%. This is the case because over time the characteristics of power supplies “sag”, and peak loads can damage the device.

As computer science says, the structure of a computer is absolutely independent of the selected power supply. They are universal and suitable for any configuration. However, more powerful power supplies have a larger size and an increased number of connectors of the same type. In the vast majority of cases, the number of connectors is excessive even on power supplies with the lowest power.

It is better not to use cheap PBs produced by no-name manufacturers. PC devices are supplied with low voltage (from 3 to 12 Volts), and even a slight fluctuation in this indicator can damage some hardware. In addition, in practice, such power supplies produce a power that is a quarter less than the data in the data sheet.

Instead of an afterword

Educational program on the topic “building a computer for dummies” is completed. It does not describe completely exhaustive information. In such descriptions, one can go in depth endlessly, describing technical details, but for the average user, the information provided in this article is sufficient. Understanding already at this level, you cannot call yourself a beginner or a beginner.

According to its purpose, a computer is a universal device for working with information. According to the principles of its design, a computer is a model of a person working with information.

Personal Computer(PC) is a computer designed to serve one workstation. Its characteristics may differ from mainframe computers, but it is functionally capable of performing similar operations. According to the method of operation, desktop (desktop), portable (laptop and notebook) and pocket (palmtop) PC models are distinguished.

Hardware. Since the computer provides all three classes of information methods for working with data (hardware, software and natural), it is customary to speak of a computer system as consisting of hardware and software working together. The components that make up the hardware of a computer are called hardware. They perform all the physical work with data: registration, storage, transportation and transformation, both in form and content, and also present them in a form convenient for interaction with natural human information methods.

The totality of a computer's hardware is called its hardware configuration.

YouTube Video

Software. Programs can be in two states: active and passive. In a passive state, the program does not work and looks like data, the content of which is information. In this state, the contents of the program can be “read” by other programs, like books are read, and changed. From it you can find out the purpose of the program and how it works. In the passive state, programs are created, edited, stored and transported. The process of creating and editing programs is called programming.

When a program is in an active state, the content of its data is considered as commands according to which the computer hardware operates. To change the order of their operation, it is enough to interrupt the execution of one program and start the execution of another, containing a different set of commands.

The collection of programs stored on a computer forms its software. The set of programs prepared for operation is called installed software. The set of programs running at one time or another is called a software configuration.

Computer device. Any computer (even the largest one) consists of four parts:

input devices

information processing devices

storage devices

information output devices.

Structurally, these parts can be combined in one case the size of a book, or each part can consist of several rather bulky devices

Basic PC hardware configuration. The basic hardware configuration of a personal computer is the minimum set of hardware sufficient to start working with a computer. Over time, the concept of a basic configuration gradually changes.

Most often, a personal computer consists of the following devices:

System unit

Monitor

Keyboard

Mouse

Additionally, other input and output devices can be connected, such as speakers, a printer, a scanner...

System unit- the main unit of a computer system. It contains devices that are considered internal. Devices connected to the system unit externally are considered external. The term peripheral equipment is also used for external devices.
Monitor- a device for visual reproduction of symbolic and graphic information. Serves as an output device. For desktop PCs, the most common monitors today are those based on cathode ray tubes. They vaguely resemble household televisions.
Keyboard- a keyboard device designed to control the operation of a computer and enter information into it. Information is entered in the form of alphanumeric character data.
Mouse- graphical control device.

Internal devices of a personal computer.
Devices located in the system unit are considered internal. Some of them are accessible on the front panel, which is convenient for quickly changing storage media, such as floppy disks. The connectors of some devices are located on the rear wall - they are used to connect peripheral equipment. Access to some system unit devices is not provided - it is not required for normal operation.

CPU. Microprocessor- the main microcircuit of a personal computer. All calculations are performed in it. The main characteristic of the processor is the clock frequency (measured in megahertz, MHz). The higher the clock speed, the higher the processor performance. So, for example, at a clock frequency of 500 MHz, the processor can change its
state 500 million times. For most operations, one clock cycle is not enough, so the number of operations a processor can perform per second depends not only on the clock speed, but also on the complexity of the operations.

The only device the existence of which the processor “knows from birth” is RAM - it works together with it. This is where data and commands come from. Data is copied into processor cells (called registers) and then converted according to the contents of the instructions. You'll get a more complete picture of how the processor interacts with RAM in the chapters on programming fundamentals.

RAM. RAM can be thought of as a vast array of cells that store numeric data and commands while the computer is turned on. The amount of RAM is measured in millions of bytes - megabytes (MB).

The processor can access any RAM cell (byte) because it has a unique numeric address. The processor cannot access an individual bit of RAM, since the bit does not have an address. At the same time, the processor can change the state of any bit, but this requires several actions.

Motherboard. The motherboard is the largest circuit board of a personal computer. It contains highways that connect the processor with RAM - the so-called buses. There is a data bus through which the processor copies data from memory cells, an address bus through which it connects to specific memory cells, and a command bus through which the processor receives commands from programs. All other internal devices of the computer are also connected to the motherboard buses. The operation of the motherboard is controlled by a microprocessor chipset - the so-called chipset.

Video adapter. A video adapter is an internal device installed in one of the connectors on the motherboard. The first personal computers did not have video adapters. Instead, a small area was allocated in RAM for storing video data. A special chip (video controller) read data from video memory cells and controlled the monitor in accordance with them.

As the graphic capabilities of computers improved, the video memory area was separated from the main RAM and, together with the video controller, was separated into a separate device, which was called a video adapter. Modern video adapters have their own computing processor (video processor), which has reduced the load on the main processor when constructing complex images. The video processor plays a particularly important role when constructing three-dimensional images on a flat screen. During such operations, he has to perform a particularly large number of mathematical calculations.

In some models of motherboards, the functions of the video adapter are performed by chipset chips - in this case they say that the video adapter is integrated with the motherboard. If the video adapter is made as a separate device, it is called a video card. The video card connector is located on the rear wall. A monitor is connected to it.

Sound adapter. For IBM PC computers, work with sound was not initially provided. For the first ten years of its existence, computers of this platform were considered office equipment and did without sound devices. Currently, audio tools are considered standard. To do this, a sound adapter is installed on the motherboard. It can be integrated into the motherboard chipset or implemented as a separate plug-in card called a sound card.
The sound card connectors are located on the back wall of the computer. To play sound, speakers or headphones are connected to them. A separate connector is intended for connecting a microphone. If you have a special program, this allows you to record sound. There is also a connector (line output) for connecting to external sound recording or sound reproducing equipment (tape recorders, amplifiers, etc.).

HDD. Since the computer's RAM is cleared when the power is turned off, a device is needed to store data and programs for a long time. Currently, so-called hard drives are widely used for these purposes.
The operating principle of a hard drive is based on recording changes in the magnetic field near the recording head.

The main parameter of a hard drive is capacity, measured in gigabytes (billions of bytes), GB. The average size of a modern hard drive is 80 - 160 GB, and this parameter is steadily growing.

Floppy drive. To transport data between remote computers, so-called floppy disks are used. A standard floppy disk (floppy disk) has a relatively small capacity of 1.44 MB. By modern standards, this is completely insufficient for most data storage and transportation tasks, but the low cost of media and high availability have made floppy disks the most common storage media.

To write and read data stored on floppy disks, a special device is used - a disk drive. The drive receiving hole is located on the front panel of the system unit.

CD-ROM drive. To transport large amounts of data, it is convenient to use CD-ROMs. These discs can only read previously written data; they cannot be written to. The capacity of one disk is about 650-700 MB.

CD-ROM drives are used to read CDs. The main parameter of a CD-ROM drive is the reading speed. It is measured in multiple units. The reading speed approved in the mid-80s is taken as one. for music CDs (audio CDs). Modern CD-ROM drives provide reading speeds of 40x - 52x.
The main disadvantage of CD-ROM drives - the inability to write discs - has been overcome in modern write-once devices - CD-R. There are also CD-RW devices that allow multiple recordings.

The principle of data storage on CDs is not magnetic, like floppy disks, but optical.

Communication ports. To communicate with other devices, such as a printer, scanner, keyboard, mouse, etc., the computer is equipped with so-called ports. A port is not just a connector for connecting external equipment, although a port ends in a connector. A port is a more complex device than just a connector, having its own chips and controlled by software.

Network adapter. Network adapters are necessary for computers to be able to communicate with each other. This device ensures that the processor does not send a new portion of data to the external port until the network adapter of a neighboring computer has copied the previous portion to itself. After this, the processor is given a signal that the data has been collected and new ones can be submitted. This is how the transfer takes place.

When a network adapter “learns” from a neighboring adapter that it has a piece of data, it copies it to itself, and then checks whether it is addressed to it. If yes, it passes them to the processor. If not, it puts them on the output port, from where the network adapter of the next neighboring computer will pick them up. This is how data moves between computers until it reaches the recipient.

Network adapters can be built into the motherboard, but are often installed separately in the form of additional cards called network cards.

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

The computer structure has undergone virtually no changes over the entire period of their existence. We all also hide the main computer devices 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 being invented and put into practice.

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

Some call the system unit a processor, others confuse the hard drive with RAM. Unscrupulous computer store sellers very successfully take advantage of this ignorance. After all, if you cannot distinguish one computer device from another, then it is easy to deceive you. So first, let's do a little computer education.

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

Externally, many devices are indistinguishable, despite their different performance characteristics (RAM, processor, hard drive, etc.). They can differ significantly, both in price and performance. Look very carefully in the warranty card about what you are buying, how much it costs, and always compare it 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 to understand and correctly select all those computer devices and components that you need.

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

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

It also allows you to shield electromagnetic radiation.

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

Motherboard (system) board

(motherboard, mainboard, MB, in slang mother, mother, motherboard). It is also called the system board, since it is what unites and organizes the work of all computer components. It is into this that we insert the central processor, RAM, and video card. Hard drives, optical drives and various peripheral devices are connected to its connectors.

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

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

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

If you buy additional devices that connect inside the system unit (sound card, video card, modem, TV tuner), then carefully look to see if you have free space for them and whether 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 choose a motherboard for it, and only then the rest of the necessary devices that fit your motherboard.

Central CPU

(CPU from the 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 greatly depends on the speed of the central processor.

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

There are currently two main manufacturers leading the microprocessor market for both desktop computers and laptops. These are Intel and AMD corporations.

RAM

RAM(random access memory from the English. Random Access Memory; in computer slang - memory, RAM).

It is a non-volatile set of chips in which data and commands are temporarily stored, which are subsequently used by the central processor to perform specified operations.
Typically, RAM contains the necessary data for the operation of the operating system and running processes of various programs.

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

Hard drive (hard drive, HDD)

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

Today, this is the main data storage device on all desktop computers and many laptop models.

This market segment remained dormant for a long time. Only the volume of information stored on the hard drive increased, but not its speed.

Now HDDs are being replaced by SSD (solid-state drive) hard drives based on flash memory. Their operating speed is many times higher, but the price is still high.

Hard drive capacity is measured in Gigabytes or Terabytes.

The larger the hard drive capacity, the more different data you can store on your computer.

The hard disk drive is the biggest 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 data received by it for further output on the monitor screen.

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

Video cards are divided into external(faster) and built-in(in the form of a separate chip) into the system board (slower).

Modern 3D games will require a fairly powerful external video card, but for working in office applications, watching movies or simple games, the built-in video adapter will be enough.
Recently, processors with an integrated graphics core have begun to appear. I will tell you what this gives in one of the articles.

Optical drive (CD, DVD-RW)

– a mechanical device controlled by an electronic circuit and designed for reading, writing or erasing information using a laser of various lengths from optical storage media (CD) such as: CD, CD-R, CD-RW, DVD, DVD-R, DVD-RW, BD-R, BD-RW.
Can work with both single-layer and multi-layer 12cm or 8cm discs.

Computer power supply (PSU)

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

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

The main characteristics of the power supply are:

• Power (measured in watts)

• Efficiency (Coefficient of Efficiency)

• Built-in surge protection systems

• Cooling

• Dimensions

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

Here you choose, as they say, “with your 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 (sound speakers), as well as 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)

There is no point in considering a disk drive for reading soft magnetic disks (floppy disk drive), since it is obsolete, although many people still use it.

It was replaced by flash drives, and in place of the FDD, you can insert other necessary devices 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 floppy drives that connect via USB.

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 subtleties 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 the correct purchase to installation in the computer and configuration. Goodbye everyone.

So, what does our ordinary personal computer (PC) that we use at home or at work consist of?

Let's look at its hardware (“hardware”):

• system unit (that large box that stands on your table or under the table, on the side of it, etc.). It contains all the main components of the computer.
• peripherals(such as a monitor, keyboard, mouse, modem, scanner, etc.).

The system unit in a computer is the “main” one. If you carefully unscrew the screws from its back wall, remove the side panel and look inside, then only in appearance its structure will seem complicated. Now I will briefly describe its structure, and then I will describe the main elements in the most understandable language.

The system unit contains the following elements (not necessarily all at once):

- Power unit

— Hard disk drive (HDD)

— Floppy disk drive (FDD)

— CD or DVD drive (CD/DVD ROM)

— Connectors for additional devices (ports) on the rear (sometimes also on the front) panel, etc.

— System board (more often called motherboard), which, in turn, contains:

• microprocessor;
• mathematical coprocessor;
• clock generator;
• memory chips(RAM, ROM, cache memory, CMOS memory)
• controllers (adapters) of devices: keyboards, disks, etc.
• sound, video and network cards;
• timer, etc.

All of them are connected to the motherboard using connectors (slots). We will look at its elements in bold below.

And now, in order, about the system unit:

1 . Everything is clear with the power supply: it powers the computer. Let me just say that the higher its power rating, the cooler it is.

2. A hard disk drive (HDD - hard disk drive) is popularly called a hard drive.

This nickname arose from the slang name for the first model of a 16 KB hard drive (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 Terrabytes (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 floppy disk drive. 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.

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 discs, 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.

5 . Other additional devices can be connected to a personal computer ( mouse, printer, scanner and other). The connection is made through ports - special connectors on the rear panel.

There are parallel (LPT), serial (COM) and universal serial (USB) ports. 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.

6. The main computer devices (processor, RAM, etc.) are located on motherboard.

Microprocessor (simpler - processor) is the central unit of a PC, designed to control the operation of all machine blocks 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 frequency (largely determines the speed of the computer). The clock speed indicates how many elementary operations (cycles) the processor performs in one second.
Intel Pentium processors and its economical version Celeron are respected in the market, and their competitors - AMD Athlon with the economical version Duron are also appreciated. 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.

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, the information in RAM is not saved. 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.

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. For video cards, I trust ATI Radeon and Nvidia. The higher the video card memory, the better.

Peripherals

The computer consists of 6 groups of keys:

• Alphanumeric;
• Controls (Enter, Backspace, Ctrl, Alt, Shift, Tab, Esc, Caps Lock, Num Lock, Scroll Lock, Pause, Print Screen);
• Functional (F1-F12);
• Numeric keypad;
• Cursor controls (->,<-, Page Up, Page Down, Home, End, Delete, Insert);
• Function indicator lights (Caps Lock, Num Lock, Scroll Lock).

Mouse (mechanical, optical). Most programs use two of the three mouse keys. The left key is the main one, it controls the computer. It plays the role of the Enter key. The functions of the right key vary depending on the program. In the middle there is a scroll wheel, which you quickly get used to.

Modem - network adapter. It can be both external and internal.

The scanner automatically reads from paper media and enters any printed texts and images into the PC.

The microphone is used to input sound into the computer.

(display) is designed to display information on the screen. Most often, modern PCs use SVGA monitors with a resolution (the number of dots located horizontally and vertically on the monitor screen) of 800*600, 1024*768, 1280*1024, 1600*1200 when transmitting up to 16.8 million colors.

The monitor screen size ranges from 15 to 22 inches diagonally, but most often it is 17 inches (35.5 cm). Dot (grain) size - from 0.32 mm to 0.21 mm. The smaller it is, the better.

PCs that are equipped with television monitors (CRT) are no longer so popular. Of these, preference should be given to monitors with low radiation levels (Low Radiation). Liquid crystal displays (LCDs) are safer, and most computers have one.

Designed for printing text and graphic images. Printers are dot matrix, inkjet and laser. In dot matrix printers, the image is formed from dots using the impact method. Inkjet printers have thin tubes in the print head instead of needles - nozzles, through which tiny droplets of ink are thrown onto the paper. Inkjet printers also produce color printing by mixing base colors. The advantage is high print quality, the disadvantage is the danger of ink drying out and the high cost of consumables.

Laser printers use the electrographic method of image formation. The laser is used to create an ultra-thin beam of light that traces the contours of an invisible dotted electronic image on the surface of a pre-charged light-sensitive drum. After developing the electronic image with dye (toner) powder adhering to the discharged areas, printing is performed - transferring the toner from the drum to paper and fixing the image on the paper by heating the toner until it melts. Laser printers provide the highest quality printing with high speed. Color laser printers are widely used.

Speakers output sound. The sound quality depends - again - on the power of the speakers and the material from which the cabinets are made (preferably wood) and its volume. An important role is played by the presence of a bass reflex (hole on the front panel) and the number of reproduced frequency bands (high, mid and low speakers on each speaker).

USB flash drives, in my opinion, have become the most universal means of transferring information. This miniature device is smaller in size and weight than a lighter. It has high mechanical strength and is not afraid of electromagnetic radiation, heat and cold, dust and dirt.

The most sensitive part of the drive is the connector, covered with a cap. The capacity of these devices ranges from 256 MB to 32 GB, which allows you to select a drive of the required capacity, in accordance with your needs. Thanks to the interface, the USB drive can be connected to any modern computer. It works with Windows 98SE/Me/2000/XP/Vista/7, Mac OS 8.6 ~ 10.1, Linux 2.4 operating systems. In Windows you don’t even need to install any drivers: just plug it into a USB port and go.

Needed to input dynamic images into a computer and sound (for communication and the ability to create teleconferences).

Uninterruptable power source needed in case of a power outage.

Puff, well, in my opinion, that’s all the main thing I wanted to tell you about the computer hardware, the so-called hardware.

The article “Computer Structure” was written quite a long time ago. Therefore, if you find an error or find some inaccuracy, please write about it using the comment form. We will be very grateful to you!

What is a computer. A computer, as its name suggests (in English the word computer came from the word compute– count, calculate) – this is a computing device. In fact, the computer can’t do anything else except count, count a lot and quickly. Various peripheral output devices, such as a monitor, printer, audio equipment, webcam, etc. they are simply capable of converting the results of these calculations in different ways into signals we can understand. Various input devices (keyboards, pointing devices, tablets, etc.) are engaged in the opposite task: converting external influences into sets of commands and data understandable to the computer. What a computer simply cannot exist without is a central processor and a storage device (computer memory). The first can count, and the second can store source data and calculation results. The computer performs calculations according to a program pre-installed in it. People write programs, but the computer's job is to execute them. We’ll talk about this in a little more detail at the end of the material, but now briefly about the form in which a computer perceives information.

Part 1. Features of presenting information on a computer

The smallest unit of information for a computer is one bit., which can take two values. One of the values ​​is considered equal to 1, and the other 0. At the hardware level (computer hardware), a unit of information is represented by triggers - a class of electronic devices that have the ability to remain in one of two states for a long time. The output voltage of such electronic devices can have two values, one of which is associated with zero and the other with one. If, on the basis of semiconductors, it was possible to easily and effectively create electronic devices capable of being in, for example, three or four states for a long time, then a bit would then be considered a unit of information that takes on three or more different values. Since modern computers are built on the basis of triggers, they use a binary number system.

What is a number system. A number system is a way of representing numerical information, determined by a set of symbols. We are familiar with the decimal number system, represented by a set of numbers from 0 to 9. A computer needs two characters to represent information: 0 and 1. Why this is so - I tried to answer a little higher when I described the nature of triggers - the hardware basis of modern computers. I will show how numbers are represented in different number systems using the example of decimal, binary and hexadecimal systems. The latter is widely used in low-level programming because it is more compact than binary, and numbers presented in hexadecimal can be easily converted to 2nd and vice versa.

Decimal number system “SI10”: (0,1,2,3,4,5,6,7,8,9). Binary number system “SI2”: (0,1) Hexadecimal number system “SI16”: (0,1,2,3,4,5,6,7,8,9,A,B,C,D,E, F) (symbols A, B, C, D, E and F are used to represent the numbers 10, 11, 12, 13, 14 and 15)

So, an example: let's look at how the number 100 is represented using these systems.

“SI10”: 100= 1*100 +0*10+0*1 “SI2” : 01100100=0*128+ 1*64 +1*32 +0*16+0*8+1*4 +0*2+0*1 “SI16”: 64=6*16+4*1

It's all different positional number systems with different basis. Positional number systems are those systems in which the contribution to the total from each digit is determined not only by the value of this digit, but also by its position. Example Not The positional number system is the Roman system with its L,X,V,I. We find that the value of a number, which is designated in a positional number system with a specific base, is calculated as follows:

N=D 0 *B 0 +D 1 *B 1 +…+D n-1 *B n-1 +D n *B n, where D i is the value of the digit in the i-th place, starting from 0, and B – the basis of the number system. Don't forget that B 0 =1.

How to convert a number from hexadecimal to binary and vice versa. It’s simple, convert each digit in the hexadecimal system into 4 digits of the binary system and write the result sequentially, either from left to right or from right to left. Vice versa: you split the binary number into tetrads(4 digits strictly from right to left) and replace each tetrad separately with one of the symbols of the hexadecimal number system. If the last tetrad turns out to be incomplete, complete it with zeros on the left. Example:

1010111100110 -> 0001(1).0101(5).1110(14).0110(6) -> 15E6

In order to quickly multiply or divide a number by the base of the number system, simply shift all the digits to the left (multiplication) and to the right (division). Multiplication by 2 in the binary number system is called shift left(0 is added at the end), and integer division by 2 is shift to the right(the last character is removed). Example:

11011(27) > 1101(13)

Computer Information Units. We have figured out the minimum unit of information in computer technology - this is a bit. But the minimum addressable set of information is not a beat, but byte– a set of information represented by 8 bits and, as a result, capable of storing 256 (2 8) different values. What means minimum addressable set of information? This means that the entire computer memory is divided into sections, each of which has its own address (sequence number). The minimum size of such a section is a byte. I am, of course, simplifying the picture, but for now this idea is sufficient. Why 8 bits? This happened historically, and for the first time 8-bit (byte) addressing was used in IBM computers. They probably found it convenient that a unit of information can be easily represented by exactly two characters of the hexadecimal number system. Now let’s dispel the myths about the amount of data denoted by almost everyone with familiar words. kilobyte, megabyte, gigabyte, terabyte etc.

1 kilobyte (kb) = 2 10 bytes = 1024, not 1000 bytes. 1 megabyte (MB) = 2 20 bytes = 1048576 bytes = 1024 kilobytes, not 1000,000 bytes. 1 gigabyte (GB) = 2 30 bytes, 1 terabyte (TB) = 2 40 bytes, etc.

Part 2. Computer structure

How does a computer work?. Or What does computer consist of. The further narrative will be structured as follows. The description of the computer device will be presented at various levels. At the first level I will outline the main components of a modern computer, at the second and subsequent levels I will describe each part in more detail. To quickly find the information you need, use the following navigation.

Level 1. General computer structure

System unit

The computer system unit is the same box from which the power cord sticks out, to which the monitor, keyboard, mouse and printer are connected, and into which CDs, flash drives and other external devices are inserted. We can say that all devices that are connected to the system unit from the outside are peripheral devices– performing secondary computer tasks. Well, the system unit itself contains all the most valuable and necessary things: the power supply, the system motherboard and the central processing unit (CPU) - the “brains” of the computer. And also, modules for controlling peripheral devices (controllers), video and sound cards, a network card and modem, transport routes for transmitting information (buses) and much more useful. However, all this is primarily true for home and office computers. For example, looking at a laptop, it is difficult to say where the system unit ends and the peripheral devices begin. This whole division is arbitrary, especially since there are also communicators, tablet computers and other portable computing devices.

This category includes all devices that allow you to enter information into a computer. For example, a keyboard, mouse, joystick, web camera and touch screen allow a person to do this, and a CD or memory card reader simply reads information from external media automatically. Input devices often include only means for human input of information, while all others are called external storage media drives.

These are devices that are designed to display the results of computer calculations. The monitor displays information in graphic electronic form, the printer does almost the same thing, but on paper, and the audio system reproduces information in the form of sounds. All these are means of feedback to a person in response to his input of information through input devices.

Other devices

This category includes any devices connected to a computer, from flash cards and portable hard drives, to modems (including wi-fi), routers, etc. Classifying devices is a thankless task, since it can be done in completely different ways, and you can always be right. For example, a built-in modem can hardly be classified as a peripheral device, although an external modem performs exactly the same functions. A modem is a device for organizing communication between computers, and it does not matter where it is located. The same can be said about the network card. A hard drive is, first of all, a non-volatile storage device that can be either internal or external. The above classification of computer equipment is based primarily on the physical location of a particular device in a classic personal computer and only then on its purpose. This is just one way of classification and nothing more.

Level 2. Contents of the system unit of a modern computer

First, a few words about computer speed. This property is characterized by the clock speed and performance of the system. The higher they are, the faster the computer works, but these are not synonyms. Performance of any system component is the number of elementary operations it performs per second. Clock frequency– this is the frequency of synchronizing pulses supplied to the system input by the clock pulse generator, which, in turn, determines the number of executions sequentially operations per unit of time. But productivity can be increased by providing the ability to perform basic operations parallel at the same clock speed, as exemplified by multi-core CPU architectures. Thus, it is necessary to evaluate not only the clock speed at which the processor operates, but also its architecture.

Now about the computer components. With the case and power supply, I think everything is clear and without comment. System motherboard and central processor- This is the heart of the computer and they are the ones who manage the computing processes. A more detailed story about them below. Tires is a means of transmitting information between various computer devices. Tires are divided into control bus, which transmit command codes; address buses, which, as their name suggests, serve to pass the address of a set of arguments defined by the command context or the address where the result should be placed; And data buses, which directly transmit the data itself - arguments and results of command execution. Controllers- These are microprocessor devices designed to control hard drives, external storage media drives and other types of devices. Controllers are intermediaries between the central processing unit infrastructure and a specific device connected to the computer. HDD is a non-volatile information storage device. Non-volatility of a storage device is its ability not to lose information after a power outage. In addition to user data, the hard drive contains operating system code, including drivers for various devices. Device Driver is a program that controls its controller. An operating system, for example, Microsoft Windows, controls all devices through drivers that have a software interface that it understands. Drivers are usually developed by computer component suppliers separately for each type of operating system. Also, the system unit cannot do without a cooling system and a control panel that allows you to turn the computer on and off.

Level 3. How a computer works

How data is represented on a computer. All data for a computer is a set of numbers. How are positive ones stored? whole numbers, I told you at the very beginning. Data, which can be either positive or negative, stores the sign (0-plus, 1-minus) in the first bit (1st bit). I won’t talk in detail about the features of storing real numbers, but you should know that real numbers are represented on the computer using mantissa And exhibitors. The mantissa is a proper fraction (the numerator is less than the denominator) in which the first decimal place is greater than zero (in the binary system, this means that the first decimal place is 1). The value of real numbers is calculated by the formula D=m*2 q, where m is the mantissa, and q is the exponent equal to log 2 (D/m). In memory, the computer stores not the mantissa itself, but its significant part - the decimal places. The more digits (bits) allocated for the mantissa, the higher the accuracy of the representation of real data. Example:

The number PI in the decimal number system looks something like this: PI=3.1415926535... Let's reduce the number to the form of a proper fraction multiplied by 10 to the appropriate power: PI=3.1415926535 = 0.31415926535*10 1 =m*10 q, where m =0.31415926535, q=1.

Thus, we represented a real number as two integers, since to store the mantissa it is enough to store only the decimal places (31415926535). It must be taken into account that both the mantissa and the exponent can be both positive and negative numbers. If the number is negative, then the mantissa is negative. If the number is less than one tenth, then the exponent is negative (in the decimal system). In the binary number system, the exponent is negative if the number is less than 0.5. Now let's try to do the same in the binary number system.

Let's round the original number a little: PI 10 = 3.1415 = 3 + 0.1415 So, 3 in the binary system is 11. Now let's deal with the fractional part. 0.1415= 0 *0.5+0 *0.25+1 *0.125+…= 0 *2 -1 +0 *2 -2 +1 *2 -3 +... As a result, we get approximately the following: PI 2 =11.001001000011=0.11001001000011*2 2 =m*2 q, where m=0.11001001000011, and q=2.

Now it should become clear what I meant by the accuracy of the representation of real numbers. 14 digits were spent on the mantissa, and for the number PI it was possible to save only a few decimal places (in the decimal number system). Also, when working on a computer, you may encounter the following form of writing a number:

6.6725E-11 This is nothing more than 6.6725*10 -11 Text is a sequence of characters, and each character has its own numeric code. There are several text encodings. The most well-known and widely used text encodings are ASCII and UNICODE. Graphic arts is a sequence of dots, each of which corresponds to a specific color. Each color is represented by 3 integers: the components of red (red), green (green) and blue (blue) colors of the RGB palette. The more digits allocated for color storage, the greater the range of colors you can operate. Video is just a sequence of static frames. There are video compression technologies that, for example, store individual sections of video as one frame and a sequence of deltas - the differences between subsequent frames and the previous one. Provided that adjacent frames do not differ in absolutely all points (for example, animation), this approach allows you to save on the total amount of material. Sound is a signal that can be converted from an analogue representation to a digital one through sampling and quantization (digitization). Naturally, digitization will lead to a loss of quality, but that is the price of digital sound.

How the calculation process is organized. Motherboard- this is the printed circuit board on which the CPU (CPU). Also, RAM modules, a video card, a sound card and other devices are connected to the motherboard through special connectors. The motherboard is an aggregating link in the architecture of a modern computer. The motherboard is equipped system controller (north bridge), providing communication between the central processor and RAM and graphics controller, as well as peripheral controller (south bridge), responsible for communication with peripheral device controllers and read-only memory. The North and South Bridges together form motherboard chipset- its basic chipset. RAM or random access memory ( RAM) is a volatile computer memory that stores the executable program and the program data itself. The amount of RAM affects the performance of a computer, since it is the RAM that determines the amount of information processed at any given time. Read Only Memory (ROM) is energy Not dependent computer memory, which stores the most important information for it, including the computer's initial boot program (before loading the operating system) - BIOS(basic input/output system - basic input/output system). ROM data is usually written by the motherboard manufacturer. Video card is an independent board with its own processor and its own RAM (video memory), designed to quickly convert graphic information into a form that can be directly displayed on the screen. The video card processor is optimized for working with graphics, including processing 3D graphics. Thus, the video card processor relieves the central processor from this type of work. The higher the amount of video memory, the faster and more often the computer is able to update data on the screen, and the wider the range of colors that can be used. A central processing unit (CPU) may consist of several processors, each of which is capable of executing its own program in parallel with the others. Previously, processor and processor core were synonymous. Nowadays, a CPU can consist of several processors, and each processor can consist of several cores. Core microprocessor is arithmetic logic unit (ALU), core controller and set system registers. The ALU, as its name suggests, can perform operations on numbers loaded into registers. A set of registers is used to store the address of the current command (commands are stored in RAM, and the IP (Instruction Pointer) register points to the current command), addresses of the data loaded to execute the command, and the data itself, including the result of the command. The kernel, in fact, controls this entire process, executing low-level processor commands. Such instructions include loading data into registers, performing arithmetic operations, comparing the values ​​of two registers, moving to the next instruction, etc. The microprocessor itself communicates with the RAM through the RAM controller. Although the access time to RAM is much shorter than, for example, the time to access information on a hard drive, this time still becomes noticeable during intensive calculations. To organize the storage of data, the access time of which should be minimal, ultra-random access memory (cache memory) is used.

Who or what controls the calculation process. The calculation process, as I said at the beginning, is controlled by a computer program. Programs are written in various programming languages ​​and most often in . The main high-level ones are: declaring variables of various types, performing arithmetic and logical operations, conditional operators and loops. A person programming in a high-level language does not need to think about how the information he processes is represented in the computer. All calculations are mainly described in the decimal number system familiar to him. The programmer defines it in the form in which it is convenient for him. He has at his disposal a serious arsenal of ready-made software components, solutions and programming technologies: organizational tools, services for working with, etc. and so on. Further, special programs called compilers translate the program text into machine code - into a command language understandable to the computer's central processor. What a program looks like in a high-level programming language can, for example, be seen on the pages of this site, and what a program looks like in a low-level language close to machine code (), see below (this program just displays the message “Hello, world”) .

386 .model flat, stdcall option casemap:none include \masm32\include\windows.inc include \masm32\include\kernel32.inc includelib \masm32\lib\kernel32.lib .data msg db "Hello, world", 13, 10 len equ $-msg .data?

written dd? .code start: push -11 call GetStdHandle push 0 push OFFSET written push len push OFFSET msg push eax call WriteFile push 0 call ExitProcess end start

One statement in a high-level language is transformed into tens or even hundreds of lines of machine code, but since this happens automatically, there is no need to worry about this. At the moment the program is launched, the operating system allocates a separate one for it, loads the machine code into RAM, initializes the registers (the address of the very first instruction is placed in the IP register), and the computing process begins.