In Lesson 8, we will learn about main peripherals personal computer, i.e. about external PC devices.

The more computer technology develops, the more incomprehensible “things” appear (both in name and purpose). In this lesson, we will deal with the most basic devices that can be connected to a computer. In addition, I will try to answer the questions “do I need this device” and “how to connect it”.

First, let's figure out what kind of words "peripheral devices" are.

Periphery(from the Greek circle) - a part of something that is far from the center.

Peripherals(PU) - equipment designed for external processing of information. In other words, these are devices located outside the system unit - external devices.

If you consistently read IT lessons, then we also got acquainted with:

1. devices that are designed to enter information to a computer for processing, and
2. devices, to display information out of him.
3. There are also devices to store information outside the system unit (external drives).

All of the above apply to external or peripheral devices. personal computer.

With the introduction finished, let's move on to the devices themselves, I will list them in order of importance for the average PC user.

Keyboard and mouse

These are the main devices for entering information, the need for them is obvious and is not discussed until touch monitors replaced the usual ones :)

The keyboard and mouse can be connected to the computer using two types of connectors:

• PS/2
• USB.

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Video supplement

In addition, today's video about choosing a keyboard. Described in sufficient detail differences between keyboards, various connection methods, affected some subtleties, which not everyone pays attention to when buying.

Peripherals. Peripherals include:

Peripherals include:

Keyboard,

Mouse manipulator

monitors,

printers,

Other devices.

Let's consider these devices in more detail.

Keyboard - This is a keyboard device that serves to enter alphanumeric data, as well as control commands.

The keyboard belongs to the standard means of a personal computer. Its main functions do not require the support of special programs (drivers). The necessary software to get started with the computer is already in the ROM chip as part of the basic input/output system (BIOS), so the computer responds to keystrokes as soon as it is turned on.

The standard keyboard of modern personal computers has 102 keys, functionally divided into four groups:

Alphanumeric keys

Function keys

Service keys

Additional keys

Mouse manipulator - this is a device for controlling a special pointer (mouse pointer) on the monitor screen. Mouse movement on a flat surface is synchronized with the movement of the mouse pointer on the monitor screen.

Monitor - This is a visual representation of data. It is not the only, but the main output device. Its main operating parameters are:

Screen size,

Maximum refresh rate,

Protection class.

Screen size The monitor is measured diagonally between opposite corners of the screen. The unit of measure is inches. Standard screen sizes are 14”, 15”, 17”, 19”, 21”. Currently, the most common screen size is 17 inches. However, for working with graphics, it is desirable to have dimensions of 19-21 inches.

Currently, there are two main types of monitors used in personal computers:

monitors on cathode ray tubes,

Monitors on liquid crystals.

Plasma monitors

In cathode ray tube monitors the image on the screen is obtained by irradiating the phosphor coating with three highly directed electron beams. To obtain a color image, the phosphor coating has dots or stripes of three types, glowing in red, green and blue. In order for all three beams to converge strictly to one point on the screen, and the image to be clear, a mask is installed in front of the phosphor - a special panel with regularly spaced holes or slots. The mask pitch is measured in fractions of a millimeter. Currently, the most common monitors have a mask pitch of 0.25-0.27mm.

In liquid crystal monitors, the image is a collection of individual dots - pixels. However, the principle of operation of LCD monitors differs significantly from the principle of operation of a CRT-based monitor. The differences lie in the ways of creating a luminous element and forming a raster.

In an LCD monitor, the smallest image element is the LCD cell. Unlike a phosphor grain, an LCD cell does not generate light, but only controls the intensity of the transmitted light. LCD monitors do not require high voltage to form an image, so LCD monitors have very low power consumption.

a printer - This is a printing output device that allows you to receive copies of documents on paper or transparent media.

Modern personal computers use various types of printers, which differ in the principle of operation. These printers include:

matrix,

inkjet,

LED,

Laser.

Dot matrix printers These are the simplest printers. Currently almost out of use.

Inkjet printers - These are printing devices in which the image on paper is formed from spots that form when drops of dye fall on the paper. The release of dye microdroplets occurs under pressure, which develops in the print head due to vaporization.

Modern personal computers usually have many peripheral devices at their disposal.

Peripherals- these are any additional and auxiliary devices that are connected to the PC to expand its functionality.

Thanks to peripheral devices, a computer system gains flexibility and versatility.

Classification of peripheral devices by purpose.

1.Input Devices:

special keyboards;

special manipulators;

flatbed scanners;

hand scanners;

drum scanners;

form scanners;

Barcode scanners

graphics tablets (digitizers);

digital cameras).

2. Data output devices:

Dot matrix printers

· laser printers;

· LED printers;

inkjet printers.

3. Storage devices:

· streamers;

· ZIP-drives;

HiFD drives;

drives JAZ;

magneto-optical devices.

4. Data exchange devices (modems).

Let's take a look at some of the peripherals.

a printer(print - print) - a device for printing text and graphic information. Printers usually work with A4 or A3 paper. The most common today are laser and inkjet printers, matrix printers have already gone out of use.

IN dot matrix printers The print head consisted of a series of thin metal needles, which, when moving along the line, struck through the ink ribbon at the right time, and thereby ensured the formation of characters and images. Dot-matrix printers had low speed and print quality.

IN inkjet printers Pressurized ink is ejected from holes (nozzles) in the print head and then adheres to the paper. In this case, the formation of the image occurs, as it were, from separate points - a "blot". Inkjet printers are characterized by high cost of consumables.

IN laser printers the laser beam, running through the drum, electrifies it, and the electrified drum attracts particles of dry paint, after which the image is transferred from the drum to paper. Next, a sheet of paper passes through a heat drum and under the influence of heat the ink is fixed on the paper. Laser printers have high speed and print quality.

Plotter(plotter) - a device for printing large drawings, drawings and other graphic information on paper. The plotter can output graphic information on A2 paper or larger. Structurally, it can use either a roll paper drum or a horizontal tablet.

Scanner(scanner) - a device that allows you to enter graphic information into a computer. When moving through a picture (a sheet of text, a photograph, a drawing), the scanner converts the image into a numerical format and displays it on the screen. This information can then be processed by a computer.

Mouse manipulator(mouse) - a device that facilitates the input of information into a computer.

CD-ROM drive- a device for reading information recorded on laser compact discs (CD ROM - Compact Disk Read Only Memory, which means a CD with read-only memory). CDs can store a large amount of information (up to 650 MB). Such discs are used to store reference information, large encyclopedias, databases, music, video information, etc.

The main indicator for a CD-ROM drive is the speed of reading information from a CD.

DVD drive is a further development of laser technology. It uses advanced laser beam technology to write and read information from CDs. The abbreviation DVD means Digital Video Disk (digital video disk) or in another interpretation - Digital Versatile Disk (digital multi-purpose disk).

Unlike CD-ROMs, DVDs can work on both surfaces. Moreover, the technology allows you to record two layers of data on each side.

Peripherals- these are any additional and auxiliary devices that are connected to the PC to expand its functionality.

Input devices

(keyboard, mouse, trackball, joystick, scanner, microphone, etc.)

Trackball (ball manipulator) is a ball located along with the buttons on the surface of the keyboard (inverted mouse).

Moving the pointer on the screen is provided by the rotation of the ball.

Sensory manipulator. It is a mouse pad. In this case, the cursor is controlled by a simple movement of the finger on the rug.

Digitizer (graphic tablet) Allows you to create or copy drawings. The drawing is done on the surface of the digitizer with a special pen or finger. The results of the work are produced on the monitor screen.

Scanner- a device for entering information into a computer from paper. Scanners are flatbed, desktop and handheld.

Mouse- input device. Converts mechanical movements on the table into an electrical signal transmitted to the computer.

light pen- with it, you can draw pictures and write handwritten texts that immediately fall on the screen.

Information output devices

(monitor, printer, plotter, speakers, etc.)

Monitor- the main peripheral device for displaying computer-visible information.

Modem- a device for connecting computers to each other over long distances via a telephone line. You can connect to the Internet using a modem.

a printer- a device for printing information on paper. Printers are dot matrix (ink ribbon), inkjet (ink cartridge), laser (powder toner cartridge).

Microphone- audio input device: voice or music.

Plotter, or plotter, is a drawing machine that allows you to draw complex large-sized graphic images with high accuracy and speed: drawings, diagrams, maps, graphs, etc.

14. Computer memory - types, types, purpose.

computer memory provides support for one of the most important functions of a modern computer - the ability to store information for a long time

Computer memory is one of the most important issues of the computer device, as it provides support for one of the most important functions of a modern computer - the ability to store information for a long time.

One of the main elements of a computer that allows it to function normally is memory.

All personal computers use three types of memory: operational, permanent and external (various drives).

The internal memory of a computer is where the information it works with is stored. External memory (various drives) is designed for long-term storage of information

The most familiar means of machine data storage used in personal computers are RAM modules, hard disks (hard drives), floppy disks (floppy magnetic disks), CD or DVD disks, and flash memory devices.

There are two types of computer memory: internal and external. internal memory: random access memory (RAM) and read only memory (ROM). The most significant part internal storage is called RAM- random access memory. Its main purpose is to store data and programs for the tasks currently being solved. RAM. This memory is called "on-line" memory because it works very fast, so that the processor does not have to wait much when reading data from memory or writing to memory. However, the data it contains is only saved while the computer is turned on.

Read Only Memory (ROM)), which, in particular, stores the information necessary for the initial boot of the computer at the time the power is turned on. As the name implies, the information in ROM is independent of the state of the computer.

External memory is usually located outside the central part of the computer

External memory includes various magnetic media (tapes, disks), optical disks. External memory is cheaper than internal memory, but its disadvantage is that it is slower than internal memory devices.

There are CD-ROM discs that are write-once discs that cannot be erased or rewritten.

Later, rewritable laser discs, CD-RWs, were invented.

External memory It is implemented in the form of quite a variety of information storage devices and is usually structurally designed in the form of independent blocks. This, first of all, should include floppy and hard disk drives (the latter are often referred to in jargon by users as hard drives), as well as optical drives (devices for working with CD ROMs).

Types of personal computer memory

Cache. The main purpose of cache memory in a computer is to serve as a place for temporary storage of currently processed program codes and data. That is, its purpose is to serve as a buffer between various devices for storing and processing information.

BIOS (Read Only Memory). The computer also has a permanent memory in which the data is entered during manufacture. As a rule, this data cannot be changed; programs running on the computer can only read it.

The computer's non-volatile memory stores programs for checking computer hardware, initiating OS loading, and performing basic computer device maintenance functions. Often, the content of persistent memory is referred to as the BIOS. It contains a computer configuration program (SETIR), it allows you to set some characteristics of computer devices (types of video controller, hard drives and floppy drives and I / O services.

CMOS (semi-permanent memory).

a small area of ​​memory for storing computer configuration settings. It is often referred to as CMOS memory because this memory is usually implemented in a low power technology.

Video memory.

video memory, that is, the memory used to store the image displayed on the monitor screen.

and permanent memory (ROM).

Computer memory is divided into external (main): floppy and hard drives, CDDVD-ROM, CD DVD-RW, CD DVD-R and internal.

Modern personal computers usually have many peripheral devices at their disposal.

Peripherals- these are any additional and auxiliary devices that are connected to the PC to expand its functionality.

Let's take a look at some of the peripherals.

a printer(print - print) - a device for printing text and graphic information. Printers usually work with A4 or A3 paper. The most common today are laser and inkjet printers, matrix printers have already gone out of use.

IN dot matrix printers The print head consisted of a series of thin metal needles, which, when moving along the line, struck through the ink ribbon at the right time, and thereby ensured the formation of characters and images. Dot-matrix printers had low speed and print quality.

IN inkjet printers Pressurized ink is ejected from holes (nozzles) in the print head and then adheres to the paper. In this case, the formation of the image occurs, as it were, from separate points - a "blot". Inkjet printers are characterized by high cost of consumables.

IN laser printers the laser beam, running through the drum, electrifies it, and the electrified drum attracts particles of dry paint, after which the image is transferred from the drum to paper. Next, a sheet of paper passes through a heat drum and under the influence of heat the ink is fixed on the paper. Laser printers have high speed and print quality.

Plotter(plotter) - a device for printing large drawings, drawings and other graphic information on paper. The plotter can output graphic information on A2 paper or larger. Structurally, it can use either a roll paper drum or a horizontal tablet.

Scanner(scanner) - a device that allows you to enter graphic information into a computer. When moving through a picture (a sheet of text, a photograph, a drawing), the scanner converts the image into a numerical format and displays it on the screen. This information can then be processed by a computer.

Mouse manipulator(mouse) - a device that facilitates the input of information into a computer.

CD-ROM drive- a device for reading information recorded on laser compact discs (CD ROM - Compact Disk Read Only Memory, which means a CD with read-only memory). CDs can store a large amount of information (up to 650 MB). Such discs are used to store reference information, large encyclopedias, databases, music, video information, etc.

The main indicator for a CD-ROM drive is the speed of reading information from a CD.

DVD drive is a further development of laser technology. It uses advanced laser beam technology to write and read information from CDs. The abbreviation DVD means Digital Video Disk (digital video disk) or in another interpretation - Digital Versatile Disk (digital multi-purpose disk).