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

So let's break it down assigning function keys in Windows... We will move in order.

F1 - Windows help key or the help system for a specific program. If the program does not have an internal help system, pressing the F1 key can open the online help on the program's official website. It is clear that if the application does not have a help file or online help, nothing will happen when you press the F1 key.

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

F3 - call the search box... Facilitates the search for files and folders on the computer (if any folder is open while pressing the 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 showing 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 a list of objects in an open folder, or open page in the browser.

F6 - translate cursor to enter (transfer focus) to the address bar (like activating the address bar in F4, but without showing history).

F7-F9 have no standard features in Windows, so their effect will depend entirely on the specific application.

F10 - call the program menu... For example, in Windows 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 has no strictly defined function, but in many applications it serves to call up various kinds of additional menus.

There are also some well-established using the functional keyboard. Let's say Alt + F4 Is the closing of 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... Key assignments will vary by 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 a mode Windows boot- F8 key.

We should also mention 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 Fn + function key, you can enable and disable the touchpad and Wi-Fi, adjust the sound volume and monitor brightness, etc. What kind of action this or that function key will perform in combination with Fn, you can find out by the icons near the keys or from the instructions for the laptop.

So let's summarize. The function keys help you save the time it takes to perform the most common operations. But when working with a specific program, it is worth finding out in advance how exactly 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.

Introduction

The keyboard is one of the main parts of the computer. It is used to enter alphanumeric data and control the operation of the computer.

There are many different keyboard designs available today. Also keyboards differ in functionality.

A keyboard is something that, along with a mouse, is in direct contact with the user, and accordingly largely determines whether or not you feel comfortable 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 true and not. On the one hand, we live in an age of total domination by Windows, but even this operating system, with its graphical interface, cannot completely do without a keyboard. After all, they have not yet invented another text input device. 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 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 the computer.

> Keyboard assignment

The IBM PC keyboard is designed to enter information from the user into the computer. Typing on the keyboard is still the main method of entering alphanumeric information from the user into the computer. Each key on the keyboard is a cover for a miniature switch (mechanical or membrane). A small microprocessor contained in the keyboard monitors the state of these switches, and when each key is pressed or released, it sends a 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 sign 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, arrow keys Left, Up, Down and Right, PgUp, PgDn, Home, End and many others.

4. Right (sub) keyboard.

Functions of some keys in most programs.

(Caps Lock) - usually serves as a switch between 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 in conjunction with other keys.

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

(Esc) - cancel the last entered command.

(Tab) - Move between screen zones 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 to the "page".

(PgDn) - move down a "page".

(Ins (Insert)) - switching the insertion and replacement mode when entering information into text editors and editors without data.

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

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

(Print Screen) - print a text screen (DOS). Send a graphical screenshot to the clipboard (Windows).

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

(Scroll Lock) - smooth scrolling of the screen.

(Pause) - temporarily pauses the running program.

When you press a key, a certain number is transmitted to the computer - the number (code) of the pressed key. This code does not depend on the language or the alphabet, but only on the specific key pressed. The system contains special tables, which indicate which key corresponds to which ASCII code, and sends the required ASCII code to the program that is currently awaiting input from the keyboard, 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, in some cases should be perceived as a lowercase "a", and in others - as an uppercase "A". In addition, we would like to enter other necessary characters using the same keyboard, 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 specify several options for converting the code of the pressed key into the ASCII code of the entered character. To do this, for each script, the system stores several tables of correspondence between the code of the pressed key and the ASCII code of the character entered with its help. When, together with pressing the main keys, we also hold a certain combination of modifier keys, the system automatically switches to the desired table. Since the keyboards of Macintosh computers have five modifier keys, there are 32 possible keystrokes for each script and, therefore, 32 tables of correspondence between key codes and entered ASCII codes.

The keyboard layout is exactly the collection of all 32 tables of correspondence of key codes and characters entered with their help. When we say: “We must switch to the Russian keyboard, this means that we must activate 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, you must additionally hold down the Option key to "warn" the system that further one Unicode character will be entered in hexadecimal notation, and not four separate alphanumeric characters. Keyboard layouts are associated with a general writing system, with some "base" alphabet defined by a script. Within the framework of the same script, several keyboard layouts can exist, each of which takes into account the specifics of a particular language, that is, it serves to enter not only characters from the general basic alphabet, but also additional characters specific to a particular language. The keyboard layout is based on the language-specific arrangement of the keys on the keyboard. For example, for a Romanesque script, there are American, French, German, Spanish, and other layouts. Similarly, Russian, Ukrainian, Belarusian layouts are created for the Cyrillic script.

In "international" systems, there are tools that allow you to easily switch between different scripts and keyboard layouts, which will make it possible to use the same keyboard to enter different sets of characters in accordance with national standards and peculiarities.

Now a few words about fonts in the context of typing text from the keyboard and displaying characters.

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

In each font, for most of the 256 ASCII codes, a graphical representation is created - an image of a specific character, maintained in a single style of a specific font.

For Unicode fonts, the number of characters can be significantly more than 256, although, probably, pi one font does not contain the entire set of characters included in the full Unicode table.

There are some service symbols that are not intended for display on the screen or printing 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, icons, or even company logos. The specific form of describing the curves that make up fragments of the graphical representation of font characters depends on the type of font. Bit map fonts specify each point in the image, while PostScript, TrueType, and OpenType fonts store mathematical descriptions of the portions of the curves that make up the graphic images of the symbols.

The main means for entering data on a personal computer today is the keyboard. In English, the word "keyboard" is used to refer to this element, which literally means "keypad". The classic 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.

For the convenience of studying data input from the keyboard, all keys can be conditionally 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. Some of the buttons on the front side have an image of letters or numbers. You can also find designations of punctuation symbols and special characters. All entered letters are lowercase by default, i.e. are small in size. Each button has Russian letters next to the image of a letter of the Latin alphabet. Some buttons even have three symbols. 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 buttons have certain characters that you often see when typing. To switch the keyboard to enter these characters, you need to use the service keys. It is very easy to detect these keys. They are not responsible for the direct input of information, but they give the user additional options.

Purpose of special keys

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

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

Service keys

There are only five buttons on the keyboard to execute service commands. These are the CapsLock, Shift, Numlock, Ctrl, Alt keys. 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 key while the CapsLock indicator is activated, lowercase letters will be printed. Also the Shift key can be used 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 you need to enter a large amount of text in capital letters, just press CapsLock. To change the case back, you need to press this key again. If you press CapsLock once, an indicator on the keyboard will light up. As a result, the text will be typed in capital letters. The indicator will turn off when you double-click.

The Ctrl key is used to convert the specified parameter values. The functions of the CTRL key are prescribed by the user in manual mode; they may differ depending on the program selected by the user.

The NumLock key is used to simplify the entry of numeric parameters. From English, the name of this key is translated as fixing numbers. When a button is pressed once on the keyboard, the corresponding indicator will light up. This will make the numeric keys available on the right panel of the keyboard. If the NumLock value is off, the keys on the right side will perform cursor control functions. The indicators show whether CapsLock and NumLock are enabled on the keyboard, and which special keys on the keyboard are currently active.

Like the Ctrl button, the Alt button allows you to change options for other keys. It usually makes it possible to expand the functionality of other keys. The values ​​of this key can change from program to program. If you translate the name of this key "Alternate" from English - change, alternation. This button also has one specific feature. Depending on the program used, the right and left Alt can be responsible for different functions.

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

Keys for editing

The purpose of these buttons is to facilitate the user's work in text editors and word processing programs. The most prominent 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 for editing text is Backspace.

Pressing this button deletes characters and characters to the left of the cursor. BackSpace is also useful when working with an Internet browser. Pressing this key returns the browser 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, removes the selected objects to the trash. The Insert button is especially useful when working with text editors. It allows you to switch the keyboard to overwrite mode.

By and large, this key is used to enter text information. The beginning of editing is determined by the agreed point of replacement or insertion 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 key combination to insert this area in the desired place.

Function Keys

Function keys are special keys on the keyboard. They are located in the topmost row, designated 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 spelled out separately. So, for example, if we consider working with the text editor Microsoft Word, then pressing the F7 button allows you to start a spelling check using the dictionary, and pressing the F5 button activates the "Find and Replace" option.

You can use the F12 function key to determine the path to save the document. Perhaps the only exception is the F1 key - when you press this key, help information appears on the screen automatically. 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") translates as "to run away, to make an escape". Therefore, it is quite clear that the main purpose of this button is to return the program to its previous state. Pressing the Esc button can also help in the event that the program has stopped responding to user requests. The special Enter key is used to enter commands and launch applications.

When this key is pressed in a text editor, the cursor moves 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. When you click this button, an indent is created in the text editor. Various functions may be assigned to this key in other programs and games.

Cursor keys

This type of key is located between the abbreviated numeric keypad and the alphabet keypad. It is very easy to recognize them - they have arrows on them. Pressing the corresponding button moves the cursor one position. The Home button also belongs to the cursor keys. 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 a text or page.

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

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

(BACKSPACE) - delete the 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) - move the cursor one screen page up through the text;

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

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

(SHIFT) - holding this key down will change the case;

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

M NS NS TOA AND D R Have G AND E M A H AND NS Have L I AM T O R NS

Although the keyboard has not lost its importance for the communication of the user 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, we can confidently assert that it is almost impossible to work on a modern computer without a mouse: 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 the cursor or marker on the screen using one keyboard can be monstrously inconvenient, slow and simply ridiculous when there are special pointers for this. Mouse and trackball, which are called “in a clever way”, coordinate manipulators, are the most common devices for remote control of graphic images on the screen today. Basically, the mouse and trackball are similar to the joystick, known to anyone who is fond of computer games. There is no need to type any commands; it is enough to point with the mouse the required menu operation or an icon in the window on the screen while working in the program, and then click the button. That's all it takes, and the program will do the rest.

Mice come with two and three buttons. In fact, for almost all cases of life, two buttons are enough on the mouse. The color and design of the mouse body is also a matter of taste. The choice is huge. Designers from many companies are diligently working on this, so there is 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, a ball turned upside down. If the mouse needs to be carried around the table and, while rolling the ball, control the movement of the marker on the screen, then in trackball you just need to twist the ball with your fingers or palm in different directions.

In laptop computers, the trackball is often built right next to the keyboard, or strapped to the side or front of the computer keyboard. However, keyboards with “built-in trackball” are also available for desktop computers. And in 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 mouse fashion in laptop computers - in place of the pointer, a key with the letter J is used. This key -or J-pointer-just serves as such a joystick, which perceives pressing in different directions, and the 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 space for the mouse sometimes turns out to be difficult. By the way, roll the mouse ball not on the bare surface of the table, but on a special rubber-plastic mat. Then the mouse wears out and gets dirty less, and points much more accurately, which means it works faster and less tires 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.

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

PRINCIPLES FOR ENTERING INFORMATION WITHPAPER MEDIA

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

Determination of the coordinates of graphic elements can be done 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;

Graphic information is presented in an analytical form;

The initial data are described in a special graphic language.

All of the listed methods and methods of transforming and presenting graphic information in a computer determine the requirements for technical means of converting information for a computer into an ACS.

The 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 irregularities 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. conversion of an analog signal into a digital code.

The number of discrete elements is determined by the specified accuracy of the graphical information presentation. The amount of information about the graphic image determines the performance of the UVGI.

By sampling methods, UVGIs of automatic and semi-automatic types are distinguished. Automatic UVGI includes matrix, scanning and tracking devices; to semi-automatic - television, acoustic, optical, electrical and electromechanical devices.