Function keys- this is a row of keys F1-F12, located at the top of the keyboard. They are called functional for a reason - each key is assigned a specific function. In other words, functional keyboard programmed to call certain commands operating system. In addition, in various programs and games, function keys may have additional functions - the same as in the OS, or others, depending on the developer's intention.

So let's take a look assignment of function keys in Windows OS. We will move in order.

F1 - Windows Help Key or the help system of a specific program. If the program does not have internal system help, by pressing the F1 key, online help can be opened on the official website of the program. Obviously, if the application does not have a help file or online help, pressing F1 will do nothing.

F2 - object editing. Most commonly used to rename files and folders in Windows Explorer or other file managers.

F3 - call the search window. Facilitates the search for files and folders on the computer (if a folder is open at the time of pressing a key, the search will be carried out in it). In the browser, activates the search in the text of the page.

F4 - activation address bar and show history in Windows Explorer and browser Internet Explorer. In other applications, the function of the key may vary (for example, in file manager Total Commander the F4 key is responsible for calling the built-in file editor).

F5 - update the list of objects in an open folder, or open page in the browser.

F6 - move the cursor to type (pass focus) into the address bar (like activating the address bar in F4, but without showing the history).

F7-F9 do not have standard functions in Windows, so their effect will depend entirely on the specific application.

F10 - call the program menu. Let's say that in Explorer in Windows Vista/7 the standard menu (File, Edit, View, etc.) is hidden by default, the F10 key opens it.

F11 - switch from windowed mode to full screen and vice versa.

F12 - the key does not have a strictly defined function, but in many applications it serves to call all sorts of additional menus.

There are also some established ones using the functional keyboard. Let's say Alt+F4 is to close the active application. Combination Ctrl+F4 closes the active tab in the browser. And the combination Shift+F10 used to open the context menu.

More function keys can be used to go to BIOS or boot menu. The key assignment will depend on the model. motherboard, but quite often the F2 key is used to enter the BIOS, the F9 key is used to call the boot menu, to select the mode Windows boot- key F8.

Separately, it is worth mentioning that how function keys work on laptops. Most laptops have an Fn key. It allows you to change the action of the function keys. Using combination Fn + function key, you can turn the touchpad and Wi-Fi on and off, adjust the sound volume and monitor brightness, etc. You can find out exactly what action this or that function key will perform in combination with Fn by the icons next to the keys or from the instructions for the laptop.

So let's sum it up. The function keys will help you save the time required to perform the most common operations. But, working with a specific program, it is worthwhile to find out in advance exactly how the functional keyboard is used in it. To do this, you should use the help, since you know how to call it - one press of the F1 key is enough.

The main means for entering data on personal computer today is the keyboard. In English, the word “keyboard” is used to refer to this element, which, if translated literally, means “keyboard”. V classic version The keyboard has 101 or 102 buttons.

However, manufacturers are constantly trying to improve the input device. Because of this, on various devices you can find many layout options, special buttons, additional panels and hot keys.

All keys for the convenience of studying data entry from the keyboard can be divided into several segments. Each segment is responsible for performing certain functions.

Alphanumeric keys

Most of the keyboard is occupied by the keys used to enter commands and text. On the part of the buttons on the front side there is an image of letters or numbers. You can also find punctuation symbols and Special symbols. All entered letters are lowercase by default, i.e. are small in size. On each button, next to the image of a letter of the Latin alphabet, there are Russian letters. On some buttons, you can even see three characters. In the second row from the top there are buttons, the main purpose of which is to enter numbers.

Just like the letter keys, the number keys have certain characters that are often used when typing. To switch the keyboard to enter these characters, you need to use the service keys. Finding these keys is very easy. They are not responsible for the direct input of information, but they give the user additional opportunities.

Purpose of special keys

As a rule, the name of the special keys on the input device is fully consistent with their functions. Conventionally, all special keys can be divided into several types:

— Keys used to execute service commands;
- Keys used for editing;
- Special keys;
- Keys to perform various functions;
- Keys to control the cursor;
- Auxiliary keys.

Service keys

There are only five buttons on the keyboard for executing service commands. These are the keys CapsLock, Shift, Numlock, Ctrl, Alt. These keys are also sometimes called modifier keys because they can be used to change the assignment of other buttons. By default, the Shift key is used to enter capital letters.

If you press the Shift button while the CapsLock indicator is activated, lowercase letters will be printed. You can also use the Shift key to control the cursor. To do this, hold down Shift and move the cursor using the arrow buttons. The CapsLock key is used to change the case of letters.

If necessary, enter a large amount of text capital letters, just press CapsLock. To change the case back, you need to press this key again. If you press CapsLock once, the indicator on the keyboard will light up. As a result, the text will be typed in capital letters. The indicator will turn off when double-clicked.

The Ctrl button is used to convert the given parameter values. The functions of the CTRL key are written by the user in manual mode, they may differ depending on the program selected by the user.

For simplified input of numerical parameters, the NumLock key is used. WITH in English the name of this key is translated as fixing numbers. If you press a button once, the corresponding indicator on the keyboard will light up. As a result, on the right panel of the keyboard, number keys. If the NumLock value is off, then the keys on the right side will perform cursor control functions. You can use the indicators to determine if CapsLock and NumLock are enabled on the keyboard, and which special keys on the keyboard are currently active.

Like the Ctrl key, the Alt key allows you to change other key options. It, as a rule, makes it possible to expand the functionality of other keys. From program to program, the meaning of this key may vary. If translated from English, the name of this key is “Alternate” - change, alternation. This button also has one specific feature. Depending on the program used, the right and left Alt may be responsible for different functions.

The PrintScreen key is used to create screen images. To pause the loading of the operating system, you can use the PauseBreak key. Also, this button can stop applications or file downloads.

Keys dedicated to editing

The purpose of these buttons is to facilitate the user's work in text editors and word processing programs. The most notable key in this category is, of course, Space, or "Space". This is the longest key and is located on the bottom row of the keyboard. The purpose of the key is quite clear from its name - it is used to separate characters and words from each other. Another important button that is used to edit text is Backspace.

Pressing this button deletes characters and characters located to the left of the cursor. BackSpace is also convenient to use when working with an Internet browser. When you press this key, the browser returns to the previously opened page. The Delete key is also used to perform several actions: it can delete characters located to the right of the cursor, it puts the selected objects in the trash. The Insert button is especially useful when working with text editors. It allows you to switch the keyboard to replace mode.

By and large, this key is used to enter text information. The beginning of editing is determined by the agreed replacement or insertion point of the prepared text fragment. So, for example, if you need to select the desired area in the table and insert it into the database, you can use the Insert + Ctrl key combination to select a part of the table, and the Shift + Insert combination to insert this section in the right place.

Function keys

Function keys are special buttons on the keyboard. They are located in the very top row, denoted by the letter F and numbers from 1 to 12. Each key is used to perform a particular operation in a particular program. Those. the purpose of each function key is written separately. So, for example, if we consider working with a text editor Microsoft Word, then pressing the F7 button allows you to run a spell check using a dictionary, and pressing the F5 buttons activates the "Find and Replace" option.

You can use the F12 function key to define the save path for the document. Perhaps the only exception is the F1 key - when you press this key, help information automatically appears on the screen. Using this key makes it much easier to work with various programs and operating systems.

Special keys

To undo the last action, you can use the special Esc key. Literally, the name of this button (“Escape”) is translated as “run away, make an escape”. Therefore, it is quite clear that the main purpose of this button is to return the program to the previous state. Pressing the Esc button can also help if the program stops responding to user prompts. The special Enter key is used to enter commands and launch applications.

When you press this key in a text editor, the cursor jumps to a new line. The Tab key is used primarily when working with tables. When working with this key, the cursor moves to the next column. Clicking this button creates an indent in the text editor. In other programs and games, various functions may be assigned to this key.

Cursor keys

The keys of this type are located between the shortened number and alphabetic keyboard. It is very easy to recognize them - they show arrows. When the corresponding button is pressed, the cursor moves one position. The cursor keys also apply home button. It allows you to return the cursor to the beginning of the page or text. End is used to move the cursor to the end of text or page.

Introduction

The keyboard is one of the main parts of a computer. With its help, enter alphanumeric data and control the operation of the computer.

There are various keyboard designs available today. Keyboards also differ in functionality.

The keyboard is what, along with the mouse, is in direct contact with the user, and accordingly, it largely determines whether you will feel comfortable or not when working with a computer.

Someone will say that the keyboard is a relic, and that now the mouse is needed much more often than the keyboard. This is both true and not. On the one hand, we live in an age of total dominance of Windows, but even this operating system, with its graphical interface, cannot completely do without a keyboard. After all, no other text input device has yet been invented. Of course, many attempts are being made to develop speech recognition systems, but they are not that far from perfect, they are just monstrously far from it. Attempts are also being made to recognize handwriting, but these systems are also not perfect. And if you work in a terminal, some DOS program, or just chat, then you definitely cannot do without a keyboard.

The purpose of the abstract is to consider the keyboard as a modern basic element of a computer.

> Keyboard Assignment

The IBM PC keyboard is designed to enter information from the user into the computer. Typing on the keyboard is so far the main way to enter alphanumeric information from the user into the computer. Each key of the keyboard is a cover for a miniature switch (mechanical or membrane). The small microprocessor contained in the keyboard monitors the state of these switches, and when each key is pressed or released, it sends an appropriate message (interrupt) to the computer, and the computer programs (operating system) process these messages.

Conventionally, four groups of keys can be distinguished on the keyboard:

1. Alphanumeric and character keys (space, numbers 0-9, Latin letters A-Z, symbol Cyrillic A-Z, punctuation marks, service symbols "+", "-", "/", etc.).

2. Function keys: F1, F2, F3 .. F12.

3. Service keys: Enter, Esc, Tab, cursor control arrows Left, Up, Down and Right, PgUp, PgDn, Home, End and many others.

4. Right (auxiliary) keyboard.

Functions of some keys in most programs.

(Caps Lock) - usually serves as a switch for the upper and lower case of the keyboard.

(Shift) - switches the keyboard to the opposite mode set by the Caps Lock key.

(Alt), (Ctrl) - have no independent meaning, they work together with other keys.

(Enter) - a signal about the completion of input. Selecting a menu item. Pressing the OK button.

(Esc) - cancel the last entered command.

(Tab) - Move between screen areas or tab stops.

(Home) - move the cursor to the beginning of the line.

(End) - move the cursor to the end of the line.

(PgUp) - move up a "page".

(PgDn) - move down a "page".

(Ins (Insert)) - switching between insert and override mode when entering information in text editors and editors without data.

(Del (delete)) - delete the character under which the cursor is located.

(Backspace(<-)} - удаление символа слева от курсора.

(Print Screen) - print text screen (DOS). Sending a graphic copy of the screen to the clipboard (Windows).

(Print Screen) - forms a copy of the screen on the printer.

(Scroll Lock) - smooth scrolling of the screen.

(Pause) - temporarily suspends the running program.

When a key is pressed, a certain number is transmitted to the computer - the number (code) of the pressed key. This code does not depend on the language or alphabet, but only on the specific key pressed. The system contains special tables that indicate which ASCII code corresponds to which key, and sends the correct ASCII code to the program that is currently waiting for keyboard input, for example, to a text editor. But we would like to somehow tell the system that pressing the key on which the letter “A” is drawn should be perceived as a lowercase “a” in some cases, and as an uppercase “A” in others. In addition, we would like to use the same keyboard to enter other necessary characters, because it is stupid to connect several keyboards to one computer just to enter a few additional characters.

The so-called modifier keys - Command, Control, Option (Alt), Shift, Caps Lock allow using the same keyboard to set several options for converting the code of the pressed key into the ASCII code of the entered character. To do this, the system for each script stores several tables of correspondence between the code of the pressed key and the ASCII code of the character entered with its help. When we, along with pressing the main keys, also hold down a certain combination of modifier keys, the system automatically switches to the desired table. Since there are five modifier keys on Macintosh keyboards, there are 32 possible keystrokes for each script, and therefore 32 tables of key codes and ASCII input codes.

The keyboard layout is just the totality of all 32 tables of correspondence of key codes and the characters entered with their help. When we say: “We need to switch to the Russian keyboard, this means that we must activate the 32 “Russian” tables of the Cyrillic script.

The Unicode Hex Input keyboard layout is used to enter Unicode characters using a set of numeric code values. To do this, additionally hold down the Option key to “warn” the system that a single Unicode character in hexadecimal representation will be entered next, and not four separate alphanumeric characters. Keyboard layouts are associated with a common writing system, with some "base" alphabet defined by the script. Within the same script, there can be several keyboard layouts, each of which takes into account the specifics of a particular language, that is, it serves to enter not only characters from the common basic alphabet, but also additional characters specific to a particular language. The keyboard layout takes into account the arrangement of keys on the keyboard accepted for a given language. For example, for the Romance script, there are American, French, German, Spanish, and other layouts. Similarly, Russian, Ukrainian, Belarusian layouts have been created for the Cyrillic script.

In "international" systems, there are facilities that allow you to easily switch between different scripts and keyboard layouts, which will make it possible to enter different character sets using the same keyboard in accordance with national standards and features.

Now a few words about fonts in the context of keyboard text input and character display.

Using the keyboard, we enter the ASCII or Unicode codes of the characters we need, but at the same time we want images of the characters themselves to appear on the screen or paper, and the calculated values ​​\u200b\u200bof their codes. Moreover, we would like to change the character style depending on the style of the document or our mood, for example. Fonts are used for these purposes.

In each font, for most of the 256 ASCII codes, a graphical representation has been created - an image of a specific character, designed in the same style of a specific font.

For Unicode fonts, the number of characters can be much higher than 256, although probably no single font contains the entire set of characters included in the full Unicode table.

There are some service characters that are not intended to be displayed on the screen or printed on paper. There are no corresponding images for such symbols.

You can create fonts in which instead of letters, numbers, punctuation marks there will be images of useful graphic objects: arrows, asterisks, pictograms, or even company logos. Bit map fonts indicate each point of the image, and PostScript, TrueType, and OpenType fonts store mathematical descriptions of curve fragments that make up graphic symbols.

Special (service) keys perform the following main functions: (ENTER) - input of commands to be executed by the processor; (ESC) - cancel any action; (TAB) - move the cursor to the tab position; (INS) - switching the character insertion mode at the cursor position to the character backspace mode at the cursor position;

(DEL) - deleting a character at the cursor position;

(BACKSPACE) - delete character to the left of the cursor;

(HOME) - move the cursor to the beginning of the text;

(END) - move the cursor to the end of the text;

(PGUP) - moving the cursor one screen page up in the text;

(PGDN) - move the cursor one screen page down the text;

(ALT) and (CTRL) - when these keys are pressed simultaneously with any other, a change in the action of the latter is caused;

(SHIFT) - holding this key down provides a change of case;

(CAPS LOCK) -fixing/unfixing the case of capital letters;

M S W TOA AND D R At G AND E M A H AND P At L I AM T O R S

Although the keyboard has not yet lost its importance for the user to communicate with the computer, another device for manual input of information - the mouse - is becoming more weighty and important. But even at the risk of making an elephant out of a mouse, it is safe to say that working without a mouse on a modern computer is almost impossible: you will immediately get bogged down in the Windows graphical interface and many application programs that work with windows, menus, icons and dialog boxes.

Controlling a cursor or a marker on the screen using a single keyboard can be terribly inconvenient, slow and simply ridiculous when there are special pointer devices for this. The mouse and trackball, which are “smartly” called pointing devices, are the most common devices for remote control of graphic images on the screen today. In principle, the mouse and trackball are similar to the joystick known to anyone who is fond of computer games. You do not need to type any commands, it is enough when working in the program to point the mouse to the desired menu operation or icon in the window on the screen, and then click the button. That's all that is required, and the rest will be done by the program.

Mice come with two or three buttons. In fact, for almost all occasions on the mouse, two buttons are enough. A matter of taste is also the color and design of the body of the mouse. The choice here is huge. Designers from many companies are diligently working on this, so there are plenty to choose from.

A trackball is not much different from a mouse. In essence, this is the same mouse, but turned upside down, or rather, turned upside down with a ball. If you need to move the mouse around the table and, while rolling the ball, control the movement of the marker on the screen, then in the trackball you just need to twist the ball itself in different directions with your fingers or palm.

In laptop computers, the trackball is often built right next to the keyboard, or clipped onto the side or front of the computer keyboard. However, keyboards with a “built-in trackball” are also available for desktop computers. And in the most portable computers, instead of a mouse and a trackball, they now use a tiny pointer - a small colored pin sticking out among the keys on the keyboard, which, like a joystick, can be pressed in different directions.

And the latest search for a mouse fashion in laptop computers - instead of a pointer, a key with the letter J is used. This key - or J-pointer - just serves as such a joystick that perceives pressing in different directions, and other letter keys surrounding the J key act as buttons missing mouse or trackball.

Mice are generally more comfortable than trackballs, but trackballs require less desktop space. And if the table is littered with documents, books, drawings, finding a free place for the mouse is sometimes not easy. By the way, roll the mouse ball not on the bare surface of the table, but on a special rubber-plastic rug. Then the mouse wears out and gets dirty less, and indicates much more accurately, which means it works faster and less tiresome for the user's eyes and hands.

In addition to traditional mice connected to a computer with a thin cable through a serial port or through a special controller on an expansion board, some companies produce promising wireless mice. A number of companies produce mice that transmit information using infrared rays. There are even miniature wireless mice that fit on your finger like a ring. And the Swiss company Logitech, a recognized world leader in this field, has released a mouse connected to a computer by radio. However, these are quite expensive devices, not every user needs them.

Today mice and trackballs from Microsoft and Logitech meet the most sophisticated aesthetic and technical requirements. The de facto standard in mouse technology is the Microsoft Mouse. Mice and trackballs of all other companies are guided by this standard.

PRINCIPLES OF INFORMATION CPAPER

The input of graphic information into a computer for ACS is carried out in three stages. At the first stage, the coordinates of graphic elements are determined, at the second stage, the coordinates are converted into a digital code, at the third stage, they are recorded in the computer memory and transferred to the arithmetic unit (AU) for processing.

Coordinates of graphical elements can be determined automatically and semi-automatically. The transformation of the coordinates of graphic elements into a digital code is carried out by several methods:

The values ​​of the current coordinates of all elements are recorded in the computer memory;

Graphical information is presented in an analytical form;

The initial data are described in a special graphical language.

All of the listed methods and ways of converting and presenting graphic information in a computer determine the requirements for technical means of converting information for a computer into an automated control system.

A graphic information input device (UVGI) is a device that converts graphic data into machine codes.

Any graphic information can be considered as a set of optical inhomogeneities that differ in brightness and color. Thus, any UVGI solves the following tasks:

1. discretization of the image into elements;

2. conversion of optical information into an electrical analog signal;

3. converting an analog signal into a digital code.

The number of discrete elements is determined by the specified accuracy of representation of graphic information. The amount of information about the graphic image determines the speed of the UVGI.

According to discretization methods, UVGI of automatic and semi-automatic types are distinguished. Automatic UVGI include matrix, scanning and tracking devices; to semi-automatic - television, acoustic, optical, electrical and electromechanical devices.