Does not apply to computer peripherals. Peripheral devices of a personal computer. Operating principle of flatbed scanners

What is computer technology? What are her Various types? For examples of computer hardware and peripherals, read this article.

By definition, the different parts of a computer are part of its hardware. Computer hardware includes the central processing unit, motherboard, chips, and computer peripherals such as input/output and storage devices that have been added to the computer to enhance its capabilities. Here is an overview of different types of computer equipment with photographs.

Computer components

Here is a list of the main components of a computer along with a list multimedia devices, network hardware components, and computer peripherals. Together they form a set of computer hardware components.

Main components

System bus: This is the subsystem that transmits data within the computer. The computer bus provides logical connections between various computer peripherals. Processors use the control bus to communicate with other devices in the computer. The address bus is used to indicate the physical address. The processor, when determining the location of memory, reads or writes on the address bus. The values ​​it needs to read or write are sent to the data bus. Thus, the data bus delivers the processed data. A parallel bus is capable of carrying multiple data in parallel, while a serial bus carries data in bit form. The internal bus connects the internal components of the computer to the motherboard, and the external bus connects external peripheral devices to the motherboard.

• AGP: Abbreviated as accelerated graphics port, it is the point where the video card is attached to motherboard computer.
• HyperTransport: It is a low latency computer bus that uses high bandwidth and operates in a bidirectional manner.
• PCI:(Component Interconnect - interaction of peripheral components) refers to the computer bus connecting peripheral devices to the motherboard.
• PCI Express: This is the computer card interface format.
• USB:(Universal Serial Bus - universal serial bus), acts as an interface to the computer. USB is the most popular connection device external devices.
• QuickPath: Also known as common interface systems, QuickPath is a point-to-point interconnect processor, and is in close competition with HyperTransport.
• Serial ATA: It is a computer bus that allows data to be transferred between storage devices and the motherboard.
• Serial Attached SCSI: This is a point-to-point serial interface. Enables data transfer from storage devices such as hard drives.

It is a set of logical machines that can execute computer programs. The fundamental function of a processor is to execute a sequence of stored instructions known as programs. During its first step of operation, the processor retrieves instructions from program memory. This stage is known as the "loading" stage. In the "decode" stage, the processor breaks instructions into parts and then executes them. During the fourth stage write back, the processor writes the results of processed instructions to memory.

It is attached to the CPU and is used to lower its temperature. Fans in the computer case help maintain a constant flow of air, thereby cooling the computer components.

Firmware: It is a computer program that is built into a hardware device. It's somewhere between hardware and software. Being part of a computer program, it is similar to software, at the same time, is closely related to hardware and makes it close to hardware components.

This is central printed circuit board, abbreviated PCB, which forms a complex electronic system computer. The motherboard provides the computer system with all electrical connections, the basic circuit, and the components necessary for its operation.

This component is responsible for supplying power to the computer. It converts AC power from the mains into low voltage direct current for internal computer components.

Random access memory, abbreviated as RAM, physical memory computer. It is used for storage running programs and is attached to the motherboard.

This is a computer expansion card that allows audio signals to be input and output to and from the computer. Sound cards provide multimedia applications with audio components.

A video adapter, also known as a video card, is a hardware component that generates and displays images on a display.

Storage controllers: They are located on the motherboard or on expansion cards. Storage controllers include controllers for hard drives, CD-ROM and other devices.

Media devices

Devices such as CD, DVD, Blu-Ray, and flash drives are some of the most popular removable media information on which digital data can be stored. Tape drives and floppy disks are obsolete. Hard drives and solid state drives are used for internal storage.

CD: Known as CD, a device for storing digital data. Standard CDs can store about 80 minutes of audio. The CD-ROM contains data that is readable and cannot be changed. CD-ROMs are used to distribute computer programs and multimedia applications. To write CDs, an optical drive is used, which uses laser light or electromagnetic waves for reading and writing data to disks.

Digital Versatile Disc: commonly known as digital video disc and abbreviated as DVD, Digital Versatile Disk is one of the very popular storage media. WITH physical dimensions Similar to a CD, DVDs can store six times more data than a CD. DVD-ROM drive is used to read data from DVD. DVD RW is used to read and write data to DVD. DVD-RAM discs allow you to write information to them multiple times. HD DVD is a high-density optical disc format.

Disc Array Controller: Controller disk array, it manages physical disk drives and represents them as logical units on the computer. It almost always implements hardware RAID, thus it is sometimes called a RAID controller. It also provides additional disk cache.

This is a disk made of a thin magnetic storage medium covered with a plastic shell. With the advent of optical storage devices, floppy disks became obsolete.

Tape drive: This storage device reads and writes data stored on magnetic tape. Tape drives have storage capacities ranging from several megabytes to several gigabytes. They are mainly used for archival data storage.

It is a non-volatile storage device that stores digital data on a magnetic surface. It is used for medium-term data storage.

Solid State Drive: Abbreviated SSD, also known as a solid state drive. This storage device uses solid-state memory to store persistent data. It can replace a hard drive in many applications, but costs significantly more.

This is an optical disc storage media format. It gets its name from the blue laser that is used to read and write such discs. Due to their short wavelength, Blu-Ray discs can store large amounts of data. BD-ROM drive is used to read data from Blu-Ray discs, BD-ROM can be used for both reading and writing.

Better known as flash drive. It is a small, removable and rewritable storage device with storage capacities ranging from 64 MB to 64 GB. Due to their high capacity, durability and compact design, they have gained immense popularity in modern times.

A medium-power floppy disk drive for storing information, developed by Iomega in 1994, had a capacity of about 100 MB, more later versions Data storage capacity increased to 250 MB and then 750 MB. The format became the most popular product to fill the portable storage niche in the late 1990s. However, it was never popular enough to replace the 3.5-inch floppy disk and could not match the storage size available on rewritable CDs and later rewritable DVDs. Flash drives eventually proved to be the preferred rewritable storage media among the general public due to the near-universal use of USB ports on personal computers, and the large size of Zip drives soon fell out of favor for mass portable storage in the early 2000s.

Network Hardware and Components

Here's a quick look at some of the pieces of hardware that make it possible for a computer to be part of a network.

LAN card: This is one of the most important parts hardware because it allows a computer to communicate with other computers over a network. It serves as a network storage medium and provides the computer with a system of MAC addresses. Network card is also known as network adapter, LAN card ( Local area network) or NIC (Network Interface Card).

Modem: This device is used for connections remote access. It demodulates analog signals to decode digital carrier information and modulates analog signals to encode the transmitted information.

Routers are not really a piece of hardware. Rather, they are devices that are used to connect multiple wired and wireless computer networks.

Computer peripherals

Apart from the hardware components of a computer, there are many external devices that are equally important for its functioning. The keyboard, mouse and monitor are the main input and output devices. Joysticks, gaming devices, and other pointing devices are commonly used for gaming applications on a computer. Headphones, speakers, microphones, and webcams are widely used to run multimedia applications. Let's look at some examples of these peripherals.

It is an input device whose design is derived from the typewriter. The keyboard consists of several keys installed in a certain way. Each key acts like an electronic switch, producing a letter, number or symbol entered into word processor or performing a specific computer operation.

Display: Known as a monitor, it is an electrical device that displays images resulting from video output from a computer.

A computer mouse is a pointing device that detects two-dimensional motion. Mouse movement is translated into pointer movement on the computer display, allowing the user to graphically control the user interface.

It is a pointing device that contains a cursor along with a ball with rotational motion sensors. Trackballs have found application in workstations special purpose and video games.

They consist of a pair of small speakers that can be held close to the ears. They can be connected to an audio source such as an amplifier or CD player.

This is an acoustic transducer that converts sound signals into electrical signals. Typically, microphones consist of a membrane that vibrates in response to sound. The vibrations are translated into electrical signals.

This peripheral produces paper copies electronic documents. It is attached to the computer using a peripheral cable or USB cable. The printer is often produced in combination with a scanner, which serves as a copying tool.

It is a peripheral device that can scan pictures, handwriting, or objects and convert them into digital images.

It is an input device that is used in video games or entertainment systems to provide input to a video game, typically to control an object or character in the game.

Speaker: External computer speakers that allow computer users to listen to audio files.

A webcam is a small camera that is widely used during video conferencing and instant messaging. They represent digital cameras, which can upload images to a web server.

This was an introduction to the different types of computer hardware. As computer technology advances, we can look forward to the development of many other hardware components that translate technology into action!

The main purpose of the PU is to ensure entry into the PC from environment programs and data for processing, as well as the output of PC operating results in a form suitable for human perception or for transfer to another computer, or in another necessary form. Peripherals can be divided into several groups according to functional purpose:

I/O devices - designed to input information into a PC, output it in the format required by the operator, or exchange information with other PCs. This type of control unit includes external drives (tape, magneto-optical) and modems.

Output devices – designed to display information in the format required by the operator. This type of peripheral devices includes: printer, monitor (display), audio system.

Input Devices – Input devices are devices through which information can be entered into a computer. Their main purpose is to implement an impact on the machine. This type of peripheral devices includes: keyboard (included in the basic PC configuration), scanner, graphics tablet, etc.

Additional control units - such as a mouse manipulator, which only provides convenient control graphical interface PC operating systems and does not have distinct functions for input or output of information; WEB-cameras that facilitate the transmission of video and audio information on the Internet, or between other PCs.

Chapter 2. Peripheral input devices

2.1 External drives

Tape (magnetic) drives – streamers. Due to the fairly large volume and fairly high reliability, they are most often used as part of data backup devices in enterprises and in large companies(store backup copies of databases and other important information). On tape drive not just saved backup copy data, but also creates an image of the data storage. This allows the user to restore a specific state or use this image as a reference data bank, for example when data has been changed. The principle of recording on magnetic media is based on changes in magnetization individual areas magnetic layer of the carrier. Recording is carried out using a magnetic head, which creates a magnetic field. When reading information, magnetized areas create weak currents in the magnetic head, which turn into a binary code corresponding to what was written.

Magneto-optical drives – CD-ROM, CD-R, CD-RW, DVD-R, DVD-RW drives. They can also be used as backup devices, but, unlike streamers, they have a much smaller data capacity (CD-R, CD-RW up to 700 MB of data, DVD-R, DVD-RW up to 4.7 GB of data). Information on magneto-optical CD-R drives is represented by alternating depressions and peaks. This relief is created mechanically during production. Information is applied along thin tracks. Reading occurs by scanning the tracks with a laser beam, which is reflected differently from the depressions and peaks. On disks that allow multiple rewrites, the magneto-optical principle is used, which is based on a physical property: the reflection coefficient of a laser beam from differently magnetized areas of a disk with a specially applied magnetic coating is different.

2.2 Flash cards

As soon as computers learned to process data arrays, the problem arose of where and how to store and transfer this data. There were many solutions - from paper punched cards to magnetic tapes and disks. Each of the technologies had many advantages and, as usual, even more disadvantages. We are all prone to laziness, looking for the most pleasant and comfortable conditions, and are not ready to make sacrifices if fashion does not require it. And therefore, as soon as the personal computer lost its status as a prestigious and expensive toy, users, in an increasingly demanding manner, began to hint to manufacturers about the inconvenience of handling them. Today the subject of our conversation is removable memory. Users have several modest requirements for this type of memory:

Energy independence – i.e. do not need batteries, the unexpected discharge of which will lead to loss of information.

Reliability - do not lose data under the influence of a thunderstorm, fall or fall into a puddle.

Compact - so as not to think about whether it’s worth carrying all this with you.

Durable - so as not to run to the store every month for a new one, because the old one has served its purpose.

Universal – compatible with many devices that may require data.

2.3 Modems

Currently, there are two types of modems: analog and digital (xDSL technology).

Analogue modems are more popular because of their low cost and are used mainly for accessing the Internet, and only sometimes (due to the low (up to 56 Kbps) data transfer speed) for communication with other PCs. Digital modems are quite expensive and are used for high speed connections With Internet, or for organization local network over long distances (xDSL modems allow you to transmit and receive information at speeds of up to 5 Mbit/s at a distance of 5-7 km).

Modems have several types of connections to the PC: COM, USB or (for digital modems) via a network card. A modem connected via a COM port requires an additional power source (unit), but when connected via a USB port, there is no need for a power supply. xDSL modems also require an additional power source.

Chapter 3. Peripheral information output devices.

Peripheral output devices are designed to display information in the format required by the operator. Among them there are mandatory (included in the basic PC configuration) and optional devices.

3.1 Monitors

The monitor is a necessary information output device. A monitor (or display) allows you to display alphanumeric or graphic information on the screen in a form that is easy for the user to read and control. In accordance with this, there are two operating modes: text and graphic. IN text mode the screen is presented in rows and columns. IN graphic format The screen parameters are set by the number of dots horizontally and the number of dot lines vertically. The number of horizontal and vertical lines on the screen is called resolution. The higher it is, the more information can be displayed per unit of screen area.

Digital monitors. The simplest - a monochrome monitor allows you to display only black and white image. Digital RGB monitors (Red-Green-Blue) support both monochrome and color modes (with 16 shades of color).

Analog monitors. Analog signal transmission is carried out in the form different levels voltage. This allows you to create a palette with shades of varying degrees of depth.

Multi-frequency monitors. The video card generates synchronization signals that relate to the horizontal line frequency and vertical frame repetition rate. The monitor must recognize these values ​​and switch to the appropriate mode.

CRT monitor According to the possibility of customization, we can distinguish: single-frequency monitors, which perceive signals of only one fixed frequency; multi-frequency, which perceive several fixed frequencies; multi-frequency, tuning to arbitrary frequencies of synchronous signals in a certain range.

Liquid crystal displays (LCD). Their appearance is associated with the struggle to reduce the size and weight of portable computers.

The main disadvantage is the impossibility quick change pictures or rapid movement of the mouse cursor, etc. Such screens require additional backlighting or external lighting. The advantages of these screens are a significant reduction in the range of harmful effects.

Gas plasma monitors. Have no restrictions LCD screens. Their disadvantage is their high energy consumption.

It is especially necessary to highlight the group of touch screens, since they allow not only to display data on the screen, but also to enter it, that is, they fall into the class of input/output devices. This one is relatively new technology has not yet received widespread use. Such screens provide the easiest and shortest way to communicate with a computer: you just need to point to what interests you. The input device is completely integrated into the monitor. Used in information and reference systems.

3.2 Printers

A printer is a widespread device for outputting information onto paper; its name is derived from the English verb to print - to print. The printer is not included in the basic PC configuration. There are different types of printers:

A typical printer operates similarly to an electric typewriter. Advantages: clear image of characters, ability to change fonts when replacing a standard disk. Disadvantages: noise during printing, low printing speed (30-40 characters/sec.), printing of graphic images is impossible.

Matrix (needle) printers are the cheapest devices that provide satisfactory print quality for a wide range of people. routine operations(mainly for preparing text documents). They are used in savings banks, in industrial environments where roll printing, printing on books and thick cards and other media made of thick material is necessary. Advantages: acceptable print quality, provided there is a good ink ribbon, and the ability to print as a carbon copy. Disadvantages: rather low printing speed, especially graphic images, significant noise level. Among the matrix printers there are quite a few fast devices(so-called Shuttle printers).

Inkjet printers provide more high quality print. They are especially useful for displaying color graphics. Using ink of different colors produces a relatively inexpensive image acceptable quality. The color model is called CMYB (Cyan-Magenta-Yellow-Black) after the names of the primary colors that form the palette.

Inkjet printers are much less noisy. Print speed depends on quality. They are quite effective when creating advertising brochures, calendars, and greeting cards. This type of printer falls somewhere between dot matrix and laser printers.

Laser printers have even higher print quality, close to photographic. They are much more expensive, but the printing speed is 4-5 times higher than that of dot matrix and inkjet printers. The disadvantage of laser printers is that they have rather strict requirements for the quality of the paper - it must be thick enough and should not be loose, printing on plastic-coated paper, etc. is unacceptable.

Particularly effective laser printers in the production of original layouts of books and brochures, business letters and materials requiring high quality. They allow you to print graphics and drawings at high speed.

LED printers are an alternative to laser ones. The developer is OKI.

Thermal printers. Used to obtain photographic quality color images. They require special paper. These printers are suitable for business graphics. Printer based on Micro Dry technology. These printers produce full photo-natural colors, have highest resolution. This is a new competitive direction. Much cheaper than laser and inkjet printers. Developed by Citizen. Prints on any paper and cardboard. The printer works with low level noise.

3.3 Plotters (graph plotters).

This device is only used in certain areas: drawings, diagrams, graphs, diagrams, etc. Plotters are widely used in conjunction with programs of automatic design systems, where design or technological documentation becomes part of the results of the program. Plotters are also indispensable when developing architectural projects. The plotter's drawing field corresponds to A0-A4 formats, although there are devices that work with a roll that do not limit the length of the output drawing (it can be several meters long). That is, there are flatbed and drum plotters.

Flatbed plotters, mainly for A2-A3 formats, fix the sheet and draw a drawing using a writing unit that moves in two coordinates. They provide higher accuracy of printing of drawings and graphs compared to drum printing.

The roll (drum) plotter remains in fact the only developing type of plotter with a roller sheet feed and a writing unit moving along one coordinate (the paper moves along another coordinate).

Cutting plotters for printing drawings on film are common; instead of a writing unit, they have a cutter. Plotters usually communicate with a computer via a serial (COM), parallel (LPT) or SCSI interface. Some plotter models are equipped with a built-in buffer (1 MB or more).

3.4 Projection technology

A multimedia projector allows you to reproduce on a large screen information received from a wide variety of signal sources: computer, VCR, video camera, photo camera, DVD player, game console. The image in a multimedia projector is formed in several main ways: using liquid crystal panels (LCD technology) and using DMD micromirror chips (DLP technology). In LCD projectors, the light from the lamp passes through a liquid crystal panel, on which it is like a regular film, but with the help of a digital electronic circuit a picture is created. Light passes through the panel and lens, and as a result, an image magnified many times is projected onto the screen. In DLP projectors, the light from the lamp is reflected from many electronically controlled micromirrors and also hits the screen through the lens.

3.5 Audio system

Personal computers use a wide variety of generation schemes. sound signals- from simple to complex. It seems that the problem with sound for personal computers has been finally solved. It's rare to see motherboards not equipped with an audio controller. However, even if we consider the issue with audio cards closed, the topic of speaker systems remains a burning issue. This question remains pressing, because many users do not limit themselves to watching videos and playing games with surround sound. True audiophiles prefer high-quality stereo sound with surround sound and deep bass, not to mention enthusiasts who create music using their personal computers. For them, a generally mandatory element of a home studio is high-quality stereo acoustics, even if the rest of the role is assigned to a computer with a sound card. There are a lot of speaker systems on the market these days that consist of two active speakers, and performed according to system 2.1. Such systems are popularly called “tweeters” because they are not capable of providing high quality sound even at low volume levels. More recently, the ideal in the world of computer (and not only) speaker systems was a 5.1 system (five satellites and one subwoofer), but in Lately Acoustic manufacturers are expanding the capabilities of their systems, which led first to the emergence of the 6.1 system, and later 8.1

Chapter 4. Peripheral input devices.

Input devices are those devices through which information can be entered into a computer. Their main purpose is to implement an impact on the PC.

4.1 Keyboard

The main input device for most computer systems is the keyboard. Until recently, a standard keyboard was used, 101/102 keys (the first keyboard model contained only 83 keys), but with the development of personal computers, manufacturers tried to develop the main information input device. This led to the creation of multimedia keyboards, with many more buttons, which are becoming more and more popular these days.

Additional keys include groups of keys for controlling multimedia applications (for example, calling and controlling video viewing programs), keys for controlling system volume, a group of keys for quick call office applications (Word, Excel), calculator, Internet Explorer, etc. Keyboards differ in two ways: connection method and design. The keyboard can be connected to a computer via the PS/2 port, USB, and via an IR (infrared) port for wireless models. In the latter connection method, the keyboard requires an additional power source, such as a battery.

4.2 Scanner

For direct reading graphic information from paper or other media to a PC is used optical scanners. The scanned image is read and converted into digital form by elements of a special device: CCD chips. There are many types and models of scanners. Which one to choose depends on the tasks for which the scanner is intended. The simplest scanners recognize only two colors: black and white. These scanners are used to read bar codes.

Hand-held scanners are the simplest and cheapest. The main disadvantage is that the person himself moves the scanner around the object, and the quality of the resulting image depends on the skill and steadiness of the hand. Another important drawback is the small scanning bandwidth (up to 10 cm), which makes reading wide originals difficult.

Drum scanners are used in professional printing activities. The principle is that the original on the drum is illuminated by a light source, and photosensors convert the reflected radiation into a digital value.

Sheet scanners. Their main difference from the previous two is that during scanning, a ruler with CCD elements is fixedly fixed, and the sheet with the scanned image moves relative to it using special rollers.

Flatbed scanners. This is the most common type now professional work. The object to be scanned is placed on a glass sheet, the image is read line by line at a uniform speed by a reading head with CCD sensors located at the bottom. Flatbed scanner can be equipped with a special slide attachment device for scanning transparencies and negatives. Slide scanners were previously used to scan slides and microimages.

Projection scanners. A relatively new direction. A color projection scanner is a powerful multifunctional tool for inputting any color images, including three-dimensional ones, into a computer. It can easily replace a camera.

Nowadays, scanners have another application - reading handwritten texts, which are then converted into ASC II codes by special character recognition programs and can subsequently be processed by text editors.

The interface may be different:

Own interface - the scanner comes with its own unique card and works only with it. This card may not work in your computer or may fail.

SCSI – if you use the scanner not with the card supplied, then easy compatibility is not always achieved.

LPT (and its variants, with support or requirement for EPP, ECP or Bi-Directional) - the scanner may need to support one of the high-speed protocols by the port. While EPP is usually always available, the 8-bit Bi-Directional option required for Epson scanners is not implemented everywhere.

USB is the most common connection option today. It’s easy to connect and, if you have all the drivers and programs, it always works.

4.3 Graphics tablet

Desktop computers for engineering and design work have been equipped with graphics tablets for more than ten years. This device greatly simplifies the entry of drawings, diagrams and drawings into a PC. At first, tablets were expensive devices and therefore were designed for purely professional use. But cheap home models have been produced for about five years now. Even despite good hand-drawing skills, you are unlikely to be able to draw anything useful in a graphics editor by moving your mouse. The pen and tablet fundamentally change the situation. If we add to this the emergence of new opportunities for graphic editors. We are talking about sensitivity to pressure. Depending on the force with which you draw the line, its thickness and transparency change in the program window. The transparent film covering the tablet allows you to trace the originals - i.e. You can put a picture under it and, tracing its lines with the tip of the pen, repeat the drawing in the editor window.

Chapter 5. Additional peripheral devices.

5.1 Manipulators

A mouse is one of the pointing input devices that provides a user interface with a computer. There are two types of mice: ball mice and optical mice.

Used in ball pointers mechanical method transmitting the direction of movement (the ball located at the bottom of the manipulator, when moving, rotates two rollers located inside).

Optical mice use an LED instead of a ball.

The mouse has several connection types: COM, PS/2, USB, IR ( infrared port). “Mice” with a connection type using a COM port are one of the first manipulators. Basically they were equipped with two buttons. It stayed on the market for quite a long time. PS/

Introduction

Chapter I. Computer peripherals

1.2 Input devices

1.3 Output devices

Chapter II. Create an educational presentation

2.1 Computer presentations

2.2 Software selection

2.3 Presentation structure

Conclusion

Literature

Introduction

The life of modern society is extremely difficult to imagine without a computer. Billions of people across the planet use them for work, leisure and education. The amazing capabilities that a computer has today simply cannot be counted. A PC is no longer considered a luxury item. This indispensable assistant, with which people can do many common things easier and faster than before. For example, write letters, keep convenient records of cash expenses and organize business notes, lists of addresses and contacts in phone book. You can also view photos, play music and video recordings using your computer.

The Internet computer network allows you to find the most useful and varied information, because the World Wide Web has almost everything! You can also use the network to communicate with friends and relatives, even if you live very far from each other. But it would be impossible to perform all these actions without peripheral devices.

There are quite a lot of sources of information on the topic “Computer Peripheral Devices”, but to get a complete picture it is necessary to collect this scattered information together, systematize and structure it.

All of the above allows us to formulate the purpose of the work: means graphic editor presentations MS Power Point to create an electronic textbook "PC Peripherals".

Collect and analyze material on the topic “PC Peripherals”.

Structure the information received.

Develop an electronic textbook using the graphical presentation editor MSPowerPoint.

Chapter I. Computer peripherals

1.1 Computer hardware

Information is one of the most valuable resources of society, along with such traditional material types of resources as oil, gas, minerals, etc., which means that the process of its processing, by analogy with the processes of processing material resources, can be perceived as technology. Then the following definition is valid.

Information technology- a process that uses a set of means and methods for collecting, processing and transmitting data (primary information) to obtain new quality information about the state of an object, process or phenomenon (information product).

In modern society, the main technical means of information processing technology is the personal computer, which has significantly influenced both the concept of construction and the use of technological processors, and the quality of the resulting information. Implementation personal computer V information sphere and the use of telecommunications have determined a new stage of development information technology and, as a consequence, changing its name by adding one of the symbols: “new”, “computer”, or “modern”. The adjective “computer” emphasizes that the main technical means of its implementation is a computer.

Computer technology- This information process, as a result of which an information product is created based on computer processing data.

The use of a computer as a tool for working with information is very diverse and multifaceted. With its help, you can browse your digital library in a few seconds and find the information you need. Special computer programs have been developed that allow, for example, a shoemaker to experiment with the shape and texture of the shoe model being created. With the help of a computer, cars are now being tested, the structure of molecules is being studied, houses are being designed and spaceships are being launched. Whatever you do - draw, play, count, type, the computer obediently follows your commands. But the computer itself cannot perform all these actions; for this it needs special devices called peripherals.

1.2 Input devices

Input Devices- hardware for converting information from a form understandable to a person into a form perceived by a computer.

Devices with keyboard input.

Keyboard. The standard device for entering information into a computer is the keyboard. With its help you can enter numeric and text information, and various commands and data. Typically, information entered from the keyboard is displayed on the monitor screen for control purposes. The location for entering information on the screen is indicated with a special icon, which is called a cursor. The appearance of the cursor may vary depending on the program used and the operating mode. This could be a blinking dash, a rectangle, etc.

Typically a 101-103 key keyboard is used American standard. In addition to the keyboard, there are membrane and touch keyboards. The keys of the alphanumeric field are additionally marked with letters of the national alphabet. If your computer has an operating system that is not configured to work in the national alphabet mode (non-localized version), then an additional special program is required - a keyboard driver. In localized versions, the keyboard driver is included in the package.

On modern computer market Ergonomic keyboards are very popular special gaskets for wrists, providing the most comfortable working conditions.

Manipulators.

Mouse. Next to the keyboard is a movable device called a mouse. There is a ball on the bottom surface of the mouse. Moving the mouse on a flat surface (table, rug) causes the ball to rotate. At the same time, it interacts with sensors inside the mouse body, resulting in a signal that causes the mouse pointer to move on the monitor screen. There are 2 or 3 buttons on the top surface of the mouse. Pressing a particular button (*a mouse click is perceived by the computer as an indication to perform some specified action. Using a mouse allows you to more quickly and conveniently control the operation of various programs.

The quality of a mouse is determined by its resolution, which is measured by the number of dots per inch - dpi (dotperinch). This characteristic determines how accurately the mouse pointer will move across the screen. For middle-class mice, the resolution is 400-800 dpi. Different types of mice differ from each other: in the way they read information (mechanical, optical-mechanical and optical), in the number of buttons (2- and 3-button mice), in the method of connection to the computer (wired - connected using a cable; wireless, or “tailless” mouse - connection to the computer is provided by an infrared signal, which is perceived by a special port).

Mouse design involves various forms of structures. The most popular are ergonomic mice, which have a streamlined surface and ensure natural placement of the hand on its surface. New is a wireless bat that works almost anywhere you want. On the desk it works like a regular mouse; If you lift it and press the button on the base, then such a mouse can be used directly in the air at a distance of up to 10 meters from the stand.

Trackball or trackball, resembles an upside-down mouse. You don’t need to move it around the table like a mouse. In a trackball, the ball is rotated by hand and the rotation is also converted into moving the pointer across the screen. It is very convenient in cases where there is little space, as it does not require a mat or space to move the manipulator around the table.

Joystick or control stick, was designed specifically for gaming. Just like a mouse and trackball, it allows you to move a cursor or graphic object across the monitor screen. The joystick is a handle that tilts in all directions, and several buttons on a small panel for performing simple actions.

Joystick have different quantity buttons number of directions to move the cursor across the screen. In order to comply with ergonomic requirements, the joystick handle has a shape that follows the relief of the hand when grasping the handle.

Touch devices.

Touch screen. A touch or tactile screen is a surface that is covered with a special layer. Touching a specific location on the screen selects a task to be performed by the computer or a command from the on-screen menu. For example, during the Olympics, touch screens help athletes, coaches, and correspondents quickly select the information they are interested in about the results of competitions, the composition of teams, etc. by pointing your finger in the corresponding menu.

The touch screen also allows you to move objects. It is easy to use, especially when needed fast access to information. Such input devices can be seen in banking computers, airports, as well as in the military and industrial sectors.

Light pen. A light pen is similar to a regular pencil, with a special device- photosensitive element. The contact of the pen with the screen closes the photoelectric circuit and determines where data is entered or corrected. If you move this stylus around the screen, you can draw or write on the screen as you would on a piece of paper.

Periphery are all external additional devices connected to the computer system unit through special connectors.

According to their purpose, peripheral devices can be divided into:

data input devices;

data output devices;

storage devices;

data exchange devices.

Input devices

Keyboard;

Mouse, trackball or touchpad;

Joystick;

Scanner;

Graphics tablet (digitizer).

Keyboard

Keyboard– a keyboard control device for a personal computer.

Serves to enter alphanumeric (character) data, as well as control commands.

The keyboard is one of the standard features of a personal computer.

Its main functions do not require support from special system programs (drivers).

The necessary software to get started with your computer is already included in the ROM chip as part of the Basic Input/Output System (BIOS), so the computer responds to key presses immediately after it is turned on.

A standard keyboard has more than 100 keys, functionally distributed into several groups:

Alphanumeric key group is intended for entering character information and commands typed by letter.

Each key can operate in several modes (registers) and, accordingly, can be used to enter several characters.

Switching between lower case (for entering lowercase characters) and upper case (for entering uppercase characters) is performed by holding the SHIFT key (non-fixed switching).

If necessary, hard register switching is used CAPS key LOCK (fixed switching).

For different languages There are various schemes for assigning symbols of national alphabets to specific alphanumeric keys. Such schemes are called keyboard layouts.

For personal IBM computers For PCs, the standard layouts are QWERTY (English) and YZUKENG (Russian).

Layouts are usually named after the symbols assigned to the first keys of the top line of the alphabetical group.

Function key group includes twelve keys (F1 to F12) located at the top of the keyboard.

The functions assigned to these keys depend on the properties of the specific program currently running, and in some cases, on the properties of the operating system.

It is a common convention in most programs that the key F1 Calls up the help system, where you can find help about the actions of other keys.

Service keys located next to the alphanumeric group keys. Due to the fact that they have to be used especially often, they have an increased size. These include the SHIFT and ENTER keys discussed above, the register keys ALT and CTRL (they are used in combination with other keys to form commands), the TAB key (for entering tab stops when typing), the ESC key (from the English word Escape) to refuse from executing the last command entered and the BACKSPACE key to delete the characters just entered (it is located above the ENTER key and is often marked with an arrow pointing to the left).

Service PRINT keys SCREEN, SCROLL LOCK and PAUSE/BREAK are located to the right of the function key group and perform specific functions depending on the operating system.

Two groups of cursor keys are located to the right of the alphanumeric pad.

A cursor is a screen element that indicates the location for entering character information.

The cursor is used when working with programs that enter data and commands from the keyboard.

Cursor keys allow you to control the input position.

The keyboard is the main data input device.

Special keyboards are designed to improve the efficiency of the data entry process.

This is achieved by changing the shape of the keyboard, the layout of its keys, or the method of connection to the system unit.

Keyboards that have a special shape, designed taking into account ergonomic requirements, are called ergonomic keyboards.

It is advisable to use them at workplaces intended for entering a large amount of character information.

Ergonomic keyboards not only increase typist productivity and reduce overall fatigue during the working day, but also reduce the likelihood and extent of developing a number of diseases, e.g. tunnel syndrome hands and osteochondrosis of the upper spine.

The key layout of standard keyboards is far from optimal. It has been preserved from the days of early examples of mechanical typewriters.

Currently, it is technically possible to manufacture keyboards with an optimized layout, and there are examples of such devices (in particular, the Dvorak keyboard is one of them).

However, the practical implementation of keyboards with a non-standard layout is questionable due to the fact that working with them requires special training.

In practice, only specialized workplaces are equipped with such keyboards.

According to the method of connection to the system unit, there are wired And wireless keyboards.

Information transmission in wireless systems is carried out by an infrared beam.

The typical range of such keyboards is several meters. The signal source is the keyboard.

Mouse

Mouse– manipulator-type control device.

Mouse movement on a flat surface is synchronized with movement graphic object(mouse pointer) on the monitor screen.

Unlike the keyboard discussed earlier, the mouse is not a standard control, and the personal computer does not have a dedicated port for it. There is no permanent dedicated interrupt for the mouse, and the computer's basic input and output system (BIOS), located in read-only memory (ROM), does not contain software to handle mouse interrupts.

Due to this, the mouse does not work the first moment after turning on the computer. It requires the support of a special system program - a mouse driver.

The driver is installed either when you connect the mouse for the first time, or when installing the computer's operating system.

Although the mouse does not have a dedicated port on the motherboard, to work with it, use one of the standard ports, tools for working with which are included in the BIOS.

The mouse driver is designed to interpret the signals coming through the port. In addition, it provides a mechanism for communicating information about the position and state of the mouse to the operating system and running programs.

The computer is controlled by moving the mouse along the plane and briefly pressing the right and left buttons (These presses are called clicks.)

Unlike a keyboard, a mouse cannot be directly used to enter character information - its control principle is event-based.

Mouse movements and mouse button clicks are events from the point of view of its driver program.

By analyzing these events, the driver determines when the event occurred and where the pointer was located on the screen at that moment. This data is transmitted to application program, with which the user is currently working. Based on them, the program can determine the command that the user had in mind and begin executing it.

A standard mouse has only two buttons, although there are custom mice with three buttons or two buttons and one rotary control.

Recently, more and more widespread mouse with scroll wheel, located between two buttons, allows you to scroll in any Windows application.

In addition to a regular mouse, there are other types of manipulators, for example: trackballs, penmouths, infrared mice.

Trackball Unlike a mouse, it is installed stationary, and its ball is driven by the palm of the hand.

The advantage of a trackball is that it does not require a smooth working surface, which is why trackballs are widely used in portable personal computers.

Penmouth is an analogue of a ballpoint pen, at the end of which, instead of a writing unit, a unit is installed that records the amount of movement.

Infrared mouse differs from normal availability wireless communication devices with the system unit.

For computer games and in some specialized simulators, lever-press type manipulators are also used ( joysticks) and similar ones joypads, gamepads and steering-pedal devices. Devices of this type are connected to a special port on the sound card or to a USB port.

Touchpad

Touchpad(English touchpad - touch pad), touch panel - a pointing input device, used most often in laptops.

Like other pointing devices, a touchpad is typically used to control the "pointer" by moving your finger across the surface of the device.

Touchpads are fairly low resolution devices. This allows them to be used in everyday work on a computer (office applications, web browsers, logic games), but makes working in graphic editors very difficult.

However, touchpads also have several advantages, compared to other manipulators:

do not require a flat surface (unlike a mouse);

do not require large space(unlike a mouse or graphics tablet) the location of the touchpad is fixed relative to the keyboard (unlike a mouse);

to move the cursor to the full screen you only need small movement finger (as opposed to a mouse or large graphics tablet);

working with them does not require much getting used to, as, for example, in the case of a trackball.

Joystick

Joystick(eng. Joystick = Joy + Stick) - a control device in computer games.

It is a lever on a stand that can be tilted in two planes.

The lever may contain various types of triggers and switches.

The word “joystick” is also commonly used to refer to a control lever, for example, in a mobile phone.

Scanner

Scanner- a device that, by analyzing an object (usually an image, text), creates a digital copy of the object’s image.

Depending on the method of scanning an object and the scanning objects themselves, there are the following types of scanners:

Tablet- the most common type of scanners, since it provides maximum convenience for the user - high quality and acceptable scanning speed. It is a tablet with a scanning mechanism inside under transparent glass.

Manual- they do not have a motor, therefore, the user has to scan the object manually, its only advantage is its low cost and mobility, while it has a lot of disadvantages - low resolution, low operating speed, narrow scanning band, image distortions are possible, since it will be difficult for the user to move the scanner at a constant speed.

Leafy- a sheet of paper is inserted into the slot and pulled along the guide rollers inside the scanner past the lamp. It is smaller in size compared to a flatbed, but can only scan individual sheets, which limits its use mainly to company offices. Many models have an automatic feeder, which allows you to quickly scan a large number of documents.

Planetary scanners- used for scanning books or easily damaged documents. When scanning there is no contact with the scanned object (as in flatbed scanners).

Book scanners- designed for scanning bound documents. Modern models of professional scanners can significantly increase the safety of documents in archives, thanks to very delicate handling of originals. Modern technologies used when scanning books and bound documents allow achieving high results. Scanning is done face up - so your scanning actions are indistinguishable from turning pages during normal reading. This prevents damage to them and allows the user to see the document during the scanning process. The software used in book scanners allows you to eliminate defects, smooth out distortions, and edit the resulting scanned pages. Book scanners have a unique book de-crease function, which ensures excellent quality of the scanned (or printed) image.

Drum scanners- used in printing, have high resolution (about 10 thousand dots per inch). The original is located on the inner or outer wall of a transparent cylinder (drum).

Slide scanners- as the name implies, they are used for scanning film slides; they are produced both as independent devices and as additional modules to conventional scanners.

Barcode scanners- small, compact models for scanning product barcodes in stores.

Operating principle of flatbed scanners:

The object to be scanned is placed on the glass of the tablet with the surface to be scanned down. Under the glass there is a movable lamp, the movement of which is controlled by a stepper motor.

The light reflected from the object, through a system of mirrors, hits a sensitive matrix (CCD - Couple-Charged Device), then to an analog-to-digital converter and is transmitted to the computer. For each step of the engine, a strip of the object is scanned, which are then combined by software into a common image.

Scanner characteristics:

Optical resolution- The scanner does not take the entire image, but line by line. A strip of light-sensitive elements moves along the vertical surface of the flatbed scanner and captures the image point by point, line by line. The more photosensitive elements a scanner has, the more points it can take pictures from each horizontal stripe. This is called optical resolution. It is usually calculated by the number of dots per inch - dpi (dots per inch). Today, a resolution level of at least 600 dpi is considered the norm.

Operation speed- Unlike printers, the speed of scanners is rarely indicated, since it depends on many factors. Sometimes the scanning speed of one line is indicated in milliseconds.

Color depth- Measured by the number of shades that the device is able to recognize. 24 bits corresponds to 16,777,216 shades. Modern scanners are produced with color depths of 24, 30, 36, 48 bits.

G graphic tablets (digitizers)

These devices are designed for entering artistic graphic information.

There are several different operating principles for graphics tablets, but they all rely on fixing the movement of a special pen relative to the tablet.

Such devices are convenient for artists and illustrators, as they allow them to create screen images using familiar techniques developed for traditional tools (pencil, pen, brush).

Technical characteristics of tablets include: resolution (lines/mm), area work area and the number of levels of pen pressure sensitivity.

Peripherals include all external additional devices connected to the computer system unit through special standard connectors.

This is computer equipment that is physically separate from the system unit computing system, It has own management and operates both on commands from its central processor and is equipped with its own processor and even an operating system. Designed for external preparation and modification of data, input, storage, protection, output, management and transmission of data via communication channels.

Computer peripheral devices are divided by purpose: