Computer structure What does a computer consist of? CMOS RAM

EXTERNAL DEVICES OF A PERSONAL COMPUTER. THEIR PURPOSE AND MAIN CHARACTERISTICS

External (peripheral) devices of a personal computer constitute the most important part of any computing complex. The cost of external devices on average is about 80-85% of the cost of our complex. External devices allow the computer to interact with environment- users, control objects and other computers.

External devices are connected to the computer through special connectors-input-output ports. PortsOutput codes are of the following types:

• parallel (designated LPT1 - LPT4) - usually used to connect printers;
• serial (designated COM1 - COM4) - usually a mouse, modem and other devices are connected to them swarms.

TO external devices relate:

• information input devices;
• information output devices;
• user dialog tools;
• means of communication and telecommunications.

TO input devices information includes:

• keyboard - device for manual entry numerical, textual and control information into the computer;
• graphics tablets(digitizers) - for manual input graphic information, images by moving a special pointer (pen) across the tablet; when you move the pen, the coordinates of its location are automatically read and these coordinates are entered into the computer;
• scanners (reading machines) - for automatically reading from paper media and entering typewritten texts, graphs, pictures, drawings into the computer;
• pointing devices (graphic manipulators) - for entering graphic information onto the monitor screen by controlling the movement of the cursor across the screen, followed by encoding the cursor coordinates and entering them into the computer (joystick, mouse, trackball, light pen);
• touch screens- for input individual elements images, programs or commands from a split-screen display to a computer).

TO output devices information includes:

• plotters (plotters) - for displaying graphic information on paper;
• printers are printing devices for outputting information onto paper.

Main types of printers:

• matrix - the image is formed from dots, the printing of which is carried out with thin needles striking the paper through an ink ribbon. The characters in a line are printed sequentially. The number of pins in the print head determines the print quality. Inexpensive printers have 9 needles. More advanced dot matrix printers have 18 and 24 needles;
• inkjet - in the print head there are thin tubes - nozzles, through which tiny droplets of ink are thrown onto the paper. The print head matrix usually contains from 12 to 64 nozzles. Currently, inkjet printers provide resolutions of up to 50 dots per millimeter and print speeds of up to 500 characters per second with excellent print quality approaching the quality of laser printing. Inkjet printers They also perform color printing, but the resolution is reduced by approximately half;
• laser - an electrographic method of image formation is used. The laser is used to create an ultra-fine light beam that draws the contours of an invisible point on the Surface of a pre-charged photosensitive drum electronic image. After developing the electronic Imagination 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.

TO user dialog tools relate:

• video terminals (monitors) - devices for displaying input and output information. The video terminal consists of a video monitor (display) and a video controller (video adapter). Video controllers are part of the computer system unit (located on the video card installed in the motherboard connector). Video monitors are external computer devices. The main characteristic of a monitor is resolution, which is determined by the maximum number of dots located horizontally and vertically on the monitor screen. Modern monitors have standard resolution values ​​from 640 X 480 to 1600 x 1200, but in reality there may be other values. Both color and monochrome monitors can be used;
• devices for speech input/output of information. These include various microphone acoustic systems, as well as various sound synthesizers that convert digital codes into letters and words that are reproduced through speakers or speakers connected to a computer.

Communications and telecommunications used to connect a computer to communication channels, other computers and computer networks. This group primarily includes network adapters. As network adapter Modems (modulator-demodulator) are most often used.

Many of the devices mentioned above belong to a conditionally selected group - multimedia.

Multimedia is a set of hardware and software that allows a person to communicate with a computer using a variety of natural environments: sound, video, graphics, texts, animation, etc. Multimedia tools include:

• speech input and output devices;
• microphones and video cameras, acoustic and video playback systems with amplifiers, sound speakers, large video screens;
• sound and video cards, video capture cards that capture images from a VCR or video camerass and entering it into the computer;
• scanners;
• external storage devices large capacity on optical disks, often used for recordingand audio and video information.

Computers are one of the most common means of obtaining information and earning money among the population. In this article, you will be able to get acquainted with the structure of most PCs that you may encounter in everyday life, unless you are a specialist in the field of computer technology.

Why is this necessary?

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

Few people who work at a computer have any idea 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 PC device, at the slightest problem he is able to quickly determine and correct its cause on his own, without waiting for professionals.

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

First meeting

Remember the first time you saw a computer. If you were then asked about what it consists of, the maximum that you could answer? Surely this is the general main device of the PC:

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

It is clear that such an answer would make any system administrator laugh at the user. Meanwhile, you are not far from the truth. With the exception of the system unit, these elements are PC peripheral devices designed to interact with the end user, that is, with you.

The most curious people from early childhood try to disassemble the system unit to see what is inside. Those who manage to do this could hardly immediately say what was before their eyes without preparation. There are many microcircuits and wires, the purpose of which we will talk about below.

PC internals 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 PC.

External devices

A separate group is the equipment that a person sees in front of him every day. External PC devices are allocated for operation and user interaction.

• Input Devices- This Hardware, intended for entering information and data into a computer.

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

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

1. Monitor.
2. Speakers, headphones or others sound devices PC.
3. A printer.

The further logic is quite easy to follow, so we will not list absolutely all PC peripheral devices. In most cases, external ones are easy enough to replace. When 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 totality has a strict structure. The basis of everything is the motherboard, which connects all the PC devices together. The connection diagram will be discussed 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;
• disk reader;
• cooling system;
• network card or built-in Wi-Fi adapter.

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

"Brain"

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

Technology development 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 the average user. This was completely enough for all computer tasks. Today, CPUs have several cores - 2, 4, 8, the power of each of which is up to several gigahertz.

However, nothing revolutionary has happened in this area over the past decades. Capacity is growing slowly, and no breakthroughs in the area of ​​information processing speed are planned.

Memory

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

PC RAM is short-term memory that contains all the data and processes when you work on the 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 it can contain and the speed of its processing.

From the point of view of its development, no special breakthrough has been noticed either. Volumes are increasing per bar, as is the speed of processing and transmitting information to the microprocessor, but nothing grandiose is expected.

A hard drive is a permanent, long-term computer memory with which the user directly works. This is where you record your information, programs and games. Memory sizes hard drive far exceed operational ones.

Volatile memory is located on the motherboard. Serves to store the most common and basic settings personal computer, such as date, time, passwords, system boot information. This memory got its name due to the fact that it requires constant replenishment of energy, which it receives through a battery, also located on the motherboard.

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

Nutrition

The thesis is clear to any schoolchild: all PC devices consume electricity. A computer power failure leads to the loss of data from RAM and volatile memory, and if the computer turns off while the user is working, not only may unsaved data be lost, but it may also be damaged existing information, which can lead to unreadable files.

Using power cables, the unit supplies +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 images on the screen, a video card is used, which is also mounted on motherboard. In many cases, the motherboard has built-in video cards, but they are too low-power to work with graphic programs or games. Therefore, people usually purchase more powerful components as part of the package.

Video cards in a computer are one of the hardest working parts. Based on this, experienced system administrators install inside the system unit additional cooling 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 inseparable part of the image is sound. A personal computer also has built-in sound cards. They provide enough high quality sound, however, for lovers of special effects, it is recommended to purchase additional elements.

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

The basis

The article has already mentioned the motherboard more than once. This is the basis of the computer, connecting all its parts together with a single chip. It serves to provide absolutely all devices of a personal computer.

Physically, this is a board on which all internal expansion strips are attached, and components located inside the system unit are also connected. 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 refuse to implement the first, transferring its functions to CPU.

Let's figure out what is called the north bridge. This is part logic circuit personal computer, designed to ensure interaction between internal devices and the south bridge. The latter is the part of the circuit responsible for the interaction of input-output 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 - the BIOS. It is responsible for the basic computer settings, loading the operating system, and possible setting some 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 has a specific function. Also everyone internal devices connected to the power supply via power wires. A little advice: when connecting expansion cards, it is better to support the motherboard with reverse side, however, due to the fact that it is attached to the body of the system unit, you can use a pencil, carefully sliding it under the chip.

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

Remember that for almost any device connected to your personal computer, installed drivers are required.

Safety

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

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

By following these tips, you can extend the life not only of yourself, but also of 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 solve a number of problems related to repairing and purchasing a PC, as well as organizing your workplace or the place of your employees. This will also help protect yourself from unnecessary expenses on spare parts with proper and timely care of your computer.

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

Hello dear visitors of the blog site. Today we’ll talk about computer devices, or as they usually say, “hardware” that can be found in the computer system unit. This way you will understand what a computer is made of. Hardware device computer, or as it is fashionable to say “hardware,” remains a mystery even for many experienced users. In this article I’ll tell you about hardware devices, thereby filling the gap, of course, if you have one, and if you are familiar with them, then we’ll refresh your memory a little.

First of all, let’s divide what is commonly called a “computer” into two groups:

• System unit. This is that big (or not very big) box to which everything is connected.
• Peripherals. You can read about peripheral devices in my article « » These are all other devices that help you work with a computer. Their main feature– they are located outside the system unit and connected to it externally.

System unit device

The system unit is the main device of the computer. Only by looking inside the computer can we figure out what the computer is made of.

1. Power unit.
2. RAM.
3. Hard drive magnetic disk.
4. Floppy disk reader.
5. Reader optical disks.
6. Additional devices.

Points 1 to 5 are mandatory; you will find them in any system unit. The rest may not exist or they may be in the form of peripheral devices, that is, connected externally.

What does computer consist of:

Now let's tell you in more detail about each component.

power unit

This computer device is an important component in the computer! The abbreviated name is BP. The main characteristic is the maximum output power. It is measured in Watts (W), in English Watt (W). For a home computer, the power supply is usually 350-450 W, for a powerful gaming computer it is 600 W or more.

The importance of this component is often underestimated. When buying a computer, you may be offered to save money by installing a lower-quality power supply. This is highly not recommended, since the power supply is the source of energy for all other components of the system. If a low-quality power supply breaks down or has some problem in the electrical network, it can damage other components of the system. In addition, cheap and low-quality models often indicate power values ​​that are far from reality. That is why the computer power supply must be from a trusted manufacturer and have sufficient power.

Name options: motherboard, mother, main board, MotherBoard, MainBoard. It is to the motherboard that all devices located inside the system unit are connected. She happens to be main board in system. Let's take a closer look at its contents:

• Socket – connector for connecting a processor. Depending on which socket your motherboard contains, you may only be able to use a certain group of processors.
• Slots for connecting a RAM module. In personal computers their number varies from 2 to 4. By type they are: DDR, DDR2 and DDR3. Modern motherboards may have two types of slots at once.
• Connectors for connecting devices and storing data. For ordinary PCs, they come in two types: a wide elongated connector with 39 pins in two rows and a small almost rectangular connector with an “r”-shaped middle. The first is a parallel interface called IDE (Integrated Drive Electronics) and its second name is PATA (Parallel ATAttachment). The second is sequential SATA interface(Serial ATtachment).
• Expansion slots. These are connectors that are used to connect additional devices. They are an elongated connector located horizontally on the lower left side of the motherboard. This is where the video card, network card and other devices are inserted. These connectors usually connect devices with motherboard By PCI interface(Peripheral component tinterconnect - interconnection of peripheral components) or its derivatives PCI Express and etc.
• Chipset. This is a set of chips that provide communication between system components. Usually it can be divided into the so-called north and south bridge. North Bridge is a memory controller, that is, a part that ensures data exchange between the central processor and RAM. IN modern platforms The memory controller can be integrated directly into the central processor. The south bridge is an I/O controller, a part that provides communication between the processor and interfaces such as SATA, IDE, PCI, USB and others.

The required components of the motherboard are listed above; they are also united by the fact that they are visible only from inside the system unit.

If you look at the back of the system unit, you can see many connectors that are also physically located on the motherboard. They are located on the left side, approximately in the middle and are enclosed in a metal “frame”. Please note that your computer may not have many of them, it depends on specific model motherboard.

• Connector for mouse and keyboard. These are two round connectors, one purple (for the keyboard) and the second green (for the mouse). This interface is called PS/2 (colloquially PS in half).
• LPT port. This parallel interface was invented as a printer port and was actively used for other purposes. Today, in motherboards, it is increasingly rare to find it on board.
• COM port. Another outdated one serial interface. This port are actively used as an interface for configuring equipment.
• USB (Universal Serial Bus - universal parallel bus). This is the most popular way to connect peripheral devices to a modern PC. Used to connect a variety of devices: mouse, keyboard, scanner, printer, portable hard drives, flash drives, etc.
• Video VGA connector, DVI. These are interfaces for connecting a monitor. If your motherboard has such a connector, then it has a built-in video adapter. It will be quite enough for work, but if you intend to play games on the computer, you will need a discrete (separate) video card, which will be inserted into a special expansion slot.
• RJ-45 network connector. The interface is used to connect a computer to a local computer network Ethernet standard.
• Group of audio connectors Jack 3.5. Used to connect speaker system and microphone. Green connector for connecting speakers and pink for microphone.

Now I propose to clarify one important point. If any connector is located in a vertical “frame” in the middle of the system unit, then the device to which it belongs is built into your motherboard. If you have a discrete video card, modem or anything else, then it is connected to the motherboard through an expansion slot and the connector of the device itself will be located below horizontally.

Central processing unit (CPU), in English CPU (Central processing unit). This is a chip that executes software commands, performs calculations, performs logical comparison operations, and roughly speaking, “thinks.” Therefore, the processor is often called the “brain” of the computer.

The main characteristics of the device are: bit capacity, clock frequency, power consumption, number of cores, architecture.

Bit capacity indicates the amount of information transmitted per unit of time over the data bus. Available in 8, 16, 32 and 64 bits. Accordingly, the higher the bit depth, the faster the processor runs. Clock frequency shows how many clock cycles (elementary operations) the CPU performs per unit of time. Power consumption indicates how much heat the processor generates when running.

Some time ago, the two main processor manufacturers - Intel and AMD - in their competition, tried to increase the clock speed of their processors as much as possible. But we were faced with the fact that after overcoming a certain threshold, energy consumption and heat transfer begin to increase nonlinearly. The solution was multi-core processors. This means that one CPU contains several crystals that distribute the computing load among themselves. The most widely used devices now are 2-core devices, although this is not the limit; there are processors with 4 or more cores.

The architecture shows how work is organized inside the processor. Although this parameter does not add the desired gigahertz, but can have a very significant impact on performance. Intelligent organization of work, as we know, costs a lot.

RAM

RAM is a random access memory (RAM), in English – RAM (Random Access Memory). This memory area is volatile, that is, without “power” the data is not saved in it. The RAM stores information that must be processed by the processor in real time. During operation, RAM contains data from the operating system and running user programs.

Today, RAM modules of the SDRAM DDR3 standard are relevant; before them there were SDRAM DDR 2 and SDRAM DDR 1 (of course, they can still be found). Each new generation had a number of serious advantages over its predecessors: increased throughput, energy consumption decreased.

HDD

A hard disk drive, or HDD (Hard Disk Drive) in English, is a read-only memory device (ROM). This device A computer is also called a hard drive or hard drive.

This type of memory is not non-volatile, that is, data is retained in memory after the power is turned off. It is this computer device that contains all the user data: movies, music, documents and everything else.

The hard drive consists of several round plates that rotate on a spindle. These plates are coated with a ferromagnetic material, divided into many cells, each of which stores one bit. binary information. A special head reads and writes information, which moves to the desired location above the surface of the disk.

They differ in the amount of stored information, connection method, form factor, and spindle speed.

As mentioned earlier, there are two types of connection method: IDE and SATA. The first one is almost never used anymore, since serial SATA is faster and more convenient. According to the form factor, HDDs come in 5.25 (discontinued production); 3.5, 2.5 inch, 1.8 inch, 1.3 inch, 1 inch and 0.85 inch are the sizes of the plates that contain the information. Desktop PCs usually use 3.5 HDDs, laptops 2.5. How faster speed rotation - the higher the speed of writing and reading data. In 3.5 models, the speed is usually 7200 rpm, in 2.5 - 5400 rpm, although there are also faster models of hard drives for laptops.

Floppy disk drive

A floppy disk drive, in English FDD (Floppy Disk Driver), is also called Floppy or simply floppy. This is a floppy disk reader. Roughly speaking, a floppy disk is a miniature hard drive, only instead of metal plates there is a flexible film base, and the head and drive motor are located in the disk drive. The size of floppy disks is 3.5 inches (5.25 inch floppy disks have been used for a long time). The floppy disk capacity is 1.44 MB. Floppy disks, in addition to their small volume, have a serious drawback - they are very unreliable, the information on them may become unreadable due to exposure to magnetic fields or shock. Because of this, this type media is almost never used today.

Optical drive

Optical media are plastic discs coated with a special layer. The disk is illuminated by a laser, and information is read from the reflected light. Optical discs come in several types: CD (Compact Disk), DVD (Digital Versatile Disc - digital multi-purpose disc), Blu-ray Disc (from English Blue Ray - blue ray). CD and DVDs There are three types: ROM (Read Only Memory), R (Recordable), RW (Re-Writable).

Drives (disk drives) for reading optical discs are called the same as media. Moreover, the drive is called by the abbreviation of the last generation in line that it is capable of reading. That is, a DVD-ROM drive reads DVDs and CDs, but a CD drive only reads CDs. Also, drives are divided into those that can only read (CD/DVD ROM) and drives that can read and write discs (CD/DVD RAM).

CD capacity 700 MB. DVD discs can be single-layer, double-layer and double-sided, the volume of regular is 4.7 GB, double-layer 8.5 GB, double-sided 9.4 GB, double-sided double-layer 17.08 GB (the latter is rare). Blu-ray Disc can store 25 GB, double layer 50 GB.

So, we have just looked at the main components that make up a computer. But we must not forget about devices that are not always included in the computer.

Additional devices (peripherals)

Additional devices can be devices that are inserted into the motherboard. Discrete (on a separate board) can be a video adapter, sound adapter, network adapter, wi-fi, modem, USB controller and many other devices.

I hope this article has fully explained to you what a computer consists of. And after reading it, the world of hadware (that’s what computer hardware is called) will become a little closer and clearer to my readers.

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” unit. 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.

— Motherboard(it is more often called maternal), 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). As a storage medium, magnetic disks use magnetic materials with special properties that make it possible to record two magnetic states, each of which is assigned a corresponding 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 . Others can also connect to a personal computer additional devices (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. The parallel port transmits information simultaneously across a large number wires corresponding to the number of digits. 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 are also appreciated - AMD Athlon with economy version Duron. Intel processors characterized by high operational reliability, low heat generation and compatibility with all software and hardware. And AMD show higher speed works with graphics and games, but is less reliable.

Computer memory can be internal or external. To devices external memory include the already discussed HDD, FDD, CD-ROM, DVD-ROM. TO internal memory includes permanent storage (ROM, ROM), operational storage (RAM, RAM), cache.

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

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 normal functioning For 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 You can always replace it, whereas if the built-in video card fails, you will have to replace the entire motherboard. From 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 Design” 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!

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.

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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 set 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 microcircuits 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 more often installed separately, in the form of additional cards called network cards.