Description of keyboard buttons in computer science. What is a computer keyboard

According to their purpose, the keys on the keyboard are conditionally divided into main groups:

Additional groups:

A number (twelve in a PC/AT keyboard) of function keys are located in the top row of the keyboard. Below is a block of alphanumeric keys. To the right of this block are the cursor keys, and at the very right edge of the keyboard is a numeric keypad, which can be removable.

Alphanumeric block

Alphanumeric keys are also referred to as alphanumeric keys, data keys, data entry keys. The basis of this block is a set similar to a typewriter. Typically, a single data key has multiple letters, numbers, punctuation, and symbols associated with it. Which letter will be entered is determined by the specified keyboard case - the mode of the keyboard, set by keys controls or shift keys.

The alphanumeric block includes keys for entering letters, numbers, punctuation marks and symbols major arithmetic operations, as well as special characters. On a standard keyboard PC/AT this block includes 47 keys. For some languages, where the number of letters in the alphabet is more than 26, keyboard manufacturers produce keyboards with additional keys in the alphanumeric block - for example, on keyboards for the Ukrainian language (33 letters), there are already 48 of them (see: Ukrainian keyboard layout). For the Russian alphabet with its 33 letters, special keyboards are not produced - all letters of the Russian alphabet are placed on the keys of the standard keyboard PC/AT.

The keys of the alphanumeric block are divided into rows and zones. [ ] The bottom row of the block is above the spacebar and modifier keys Ctrl , Alt , AltGr . He is considered the first. Above - the second, in the blind ten-finger typing method also called "home" near [ ] . Even higher - the third. The topmost row of keys in the block - the fourth - in the Latin QWERTY layout does not contain keys for entering letters, but includes all the keys for entering numbers. For this reason it often referred to as the number row [ ] . A zone is a set of keys assigned in the blind ten-finger typing method to the fingers of each hand. Zones are numbered from left to right. [ ]

The effect of the alphanumeric keys depends on the case (lower or upper) and the level (first or second) in which the keys are pressed.

Control keys

Modifier keys include ⇧ Shift , Ctrl , ⇪ Caps Lock , Alt and AltGr (right Alt). They are designed to change (modify) the actions of other keys. Turning on the upper case of the keys (when ⇪ Caps Lock is disabled) is carried out by pressing and holding the ⇧ Shift key. Pressing and holding the AltGr key is used to move to the second level of the keyboard.

Modifier keys are the most commonly used, so they are larger in size. In addition, the ⇧ Shift and Ctrl keys are duplicated on both sides of the block of alphanumeric keys.

System command keys

These include: SysRq , Esc , PrtSc , Pause , Break , ≣ Menu .

Function keys

Also on PC/AT keyboard at the top of the keyboard is a block of so-called function keys - from F1 to F12. (PC/XT keyboards had 10 function keys from F1 to F10 arranged in two columns on the left side of the keyboard.) The functions of these keys are determined depending on the system or application software: motherboard configuration program ( Setup BIOS) and, subsequently, the running operating system.

Functions of individual function keys, combinations of function keys with the ⇧ Shift , Ctrl and Alt keys and "regular" keys form part of the user interface and are usually constant for a particular type of software. There are a number of general-purpose assignments that are most widely used: often pressing F1 will display the built-in program guide (often already open on the page corresponding to the mode of the program in which it is located), and pressing ESC will abort the current operation.

Numeric keypad

The basis of this block is a set of 17 keys, similar to those used in calculators, cash registers and the like. The main purpose of the keys numeric keypad- duplication of the functions of the keys of the alphanumeric block in terms of entering numbers and symbols of basic arithmetic operations. The keys of this panel are more convenient for entering numbers and arithmetic signs than the keys of the alphanumeric block. In disabled mode, it duplicates the cursor keys.

Specialized Keys

Multimedia keyboards

Many modern computer keyboards, in addition to the standard set of 104 keys, are equipped with additional keys (usually of a different size and shape), which are designed to simplify the control of some basic computer functions:

• sound volume control: louder, quieter, turn the sound on or off;
• tray management in the CD drive: eject disc, accept disc;
• audio player control: play, pause, stop playback, fast forward or backward in an audio recording, go to the next or previous audio recording;
• managing the network capabilities of the computer: open, put into sleep mode, wake up the computer, turn off the computer.

Since many of these functions (sound and playback control, CD management, etc.) are in the realm of multimedia, these keyboards are often referred to as "multimedia keyboards".

Proprietary drivers for such keyboards, as a rule, do not provide users with the ability to control the assignment of most additional keys (except, perhaps, ad hoc group"custom keys"), and also do not allow you to define additional combinations of several keys (including multimedia) and assign new special functions to them. However, this problem can be solved by using third party independent generic drivers.

Programmable keyboards

Keyboards have been developed in which the purpose and appearance keys is changed programmatically depending on the selected character set, and even on the one running in this moment applications. Each key is actually a mini-display showing its current assignment. These can be not only symbols of various alphabets, but also icons of the "hot" keys of the application.

Keyboard- a device, which is a set of buttons (keys) designed to control a device or to enter information. As a rule, the buttons are pressed with fingers.

History of the origin of the keyboard

Most modern keyboards are descended from IBM's original keyboard, the "IBM Enhanced 101 Key Keyboard", which the company proclaimed as a standard in 1987. This type of keyboard was not the first standard, but became the most suitable for PC users.

What were the previous keyboard models like?

Initial IBM Model - XT Keyboard , had 83 buttons. There were 10 function keys on the left, keypads with numbers and pointers were on the right side. So-called buttons Control (Ctrl), left Shift And alt were located next to the function keys.

escape (esc), as we know, was to the left of the numbers in the main row. To the right of the right key shift, there was an asterisk key that allows you to print the well-known symbol *. Between the tiny left key Shift and key Z there was a symbol Backslash(slash to the right /). Key Enter was narrow and vertical, and many users often did not notice it the first time.

The design of this original IBM keyboard standard was a mixture of sensible and absurd keyboard layout decisions. Thus, some parts of it delighted and, as it were, obscured less thoughtful places and shortcomings.

The next IBM project was the AT keyboard. It was incompatible with the earlier XT project.

The keyboard, as before, had ten function keys on the left side, but the key Esc and the invariable asterisk (*) have been moved to the numeric keypad. Key Enter had an L-shape, and the key backsplash(/), which now shares space with a dot, shared space with a key in this type of keyboard backspace.

At a certain point in time, when the market was pushing IBM to upgrade their AT keyboard, they introduced a new extended keyboard design that was compatible with the original AT model, but had a completely different key layout. Key Esc and the 12 function keys were now on top, the numeric keypad was on the right.

A new pointing keypad has been placed between the letter keys and the number pad. The index keypad (which was actually split into two sets of keys) consisted of four pointers, had an inverted T-shape and was located at the base, on top was a separate panel with 6 keys:

• Ins (Insert);
• Del(Delete);
• Home and End;
• PgUp (Page Up) and PgDn (Page Down).

But then disaster struck - users started clicking Delete, instead of a key end. It doesn't seem so catastrophic today, but there were no modern software options at the time. A user who may have spent long hours typing an article hit the wrong key and all their work went down the drain.

Through a short time Complaints started coming to IBM headquarters. "From the good, the good is not sought" was said in letters addressed to IBM. Therefore the key backspace returned to its original wide size. The backslash (backslash \) key has taken over its own key. cap lock moved to the old location of the key ctrl, and the twins ctrl and keys alt located on both sides of the gap.

Key Del remained in the same place, although in some keyboards it became twice as large.

Like it or not, this arrangement has become the standard for the modern keyboard used by millions of users around the world.

It is clear that they are not just located. If you disassemble the keyboard on the computer and the typewriter and compare them ... Then it turns out that the arrangement of the letters on them is exactly the same. In fact, the keyboard was not invented for convenience, but, on the contrary, to slow down the speed of typing. And it was precisely this goal - to reduce the speed of the typesetter - that the inventor of the typewriter pursued!

The first commercial typewriter was invented by Christopher Scholes. It happened almost 150 years ago in the USA.

We can say that this machine was extremely inconvenient. The person who tried to print something was deprived of the opportunity to follow the result. Hammers with letters were under a sheet of paper. But in spite of everything, people have learned to type quite fluently even on these terrible typewriters. After some time, another problem arose: all the warranty repair shops were inundated with returned typewriters.

Separate hammers in the process of printing regularly interlocked with each other, and their separation often led to breakage. In those days, the letters on the keys were in alphabetical order.

Here is an experiment. It is necessary to circle with a felt-tip pen those frequently used in English language letters next to each other. It turns out that the situation when two adjacent keys were pressed is common. Too often! Two adjacent buttons, pressed almost simultaneously, caused the hammers to interlock and jam each other.

The conclusion suggests itself - it is necessary to space the frequently repeated letters away from each other. So Christopher Sholes did. Typing became inconvenient. But the hammers stopped breaking. The goal has been reached. AND In 1874, the Remington 1 typewriter was born. The arrangement of letters on it did not begin as before with "ABCDEF", but with "QWERTY". This arrangement of Latin letters has survived to this day!

Mechanical typewriters have improved. It was on the QWERTY keyboard that the ten-finger typing method was first introduced. Up to this point, they typed with four fingers, although there are still people who use only two index fingers. The pursuit of excellence did not end there.

In the 40s of the last century, the American Arthur Dvorak proposed his own version of the arrangement of Latin letters. He calculated that it is more convenient when frequently used letters are in the middle and upper rows. Under the left hand in the middle row, he placed all the vowels, under right hand the most frequent consonants. The load on the hands turned out to be more balanced.

It can be calculated that for an 8-hour working day, our fingers travel about two kilometers on a new keyboard. While on the traditional QWERTY keyboard, the same figure was already 7 kilometers, which, you see, is much more!

Why did Dvorak fail to convince the whole world of the benefits of his rationalization proposal? Perhaps only because no one dared to renounce the millions of cars, by that time faithfully serving humanity.

Now America. Here, typewriters appeared later than in the United States. By this time, the designers have eliminated many technical imperfections. The hammers no longer clung to each other. That is why in Russia the letters were arranged rationally - the frequently used ones ended up in the middle of the keyboard.

In conclusion, the conclusion suggests itself that our domestic layout turned out to be an order of magnitude more ergonomic than the English one. Under the strongest and fastest index fingers were the most popular letters, and under the little fingers the rarest. But still, there is one drawback.

When it came to the Russification of the computer keyboard, someone decided that the comma could be anywhere. And he settled it together with a dot, but in upper case. Now, in order to write a period, you need to press one key, and in order to write a comma, you need to press two keys! But the comma in Russian is used much more often than the dot!

You can, of course, start a fight for rationality. But remembering the story of Dvorak, who never managed to convince anyone to give up uncomfortable stereotypes... So it turns out that the whole world prints not as smarter, but as more familiar. And he does not want to change these habits!

Information sources:

• byaki.net - Who invented the keyboard layout;

A keyboard is a device for entering data into a computer: letters, numbers and signs. It is also used to control the system, that is, it is an analogue of a computer mouse. By type of connection, it is wired and wireless.

Wired connects to a computer via a USB port or a PS / 2 connector.

Wireless can be connected via a radio transmitter (USB receiver) or bluetooth. The range is usually about 10 meters.

Since wireless devices do not have a fixed power supply, they need to be charged separately. To do this, a special battery can be built into the keyboard itself, which needs to be charged from time to time. Or it can run on batteries.

Key layout

The layout of the buttons follows the same generally accepted pattern. Twelve function keys from F1 to F12 (located in the top row). Below them are alphanumeric keys. On the right are the cursor control buttons.

The far right side is the so-called number pad. It duplicates the alphanumeric block (more precisely, only numbers and arithmetic signs). Enabled with the Num Lock button.

On many keyboards, in addition to this standard set, there are also additional buttons of a different shape and size (sometimes in a different color). Their task is to simplify the management of certain functions of the computer.

So, among others, there may be buttons that control the volume, launch some programs (browser, Word, Excel), keys for controlling the player (pause, rewind).

Keyboard device

Membrane. The most popular and most inexpensive type. Inside each key is a special membrane. When pressed, it is pressed through and closes the contact. The service life of each key is about 5 million clicks.

Scissor. These keyboards are installed in all laptops. The principle of operation of the keys is similar to scissors - hence the name. Pressing is soft and clear, which is very convenient when typing. But it costs more. Service life is about 10 million clicks.

Mechanical. The best, but also the most expensive kind. Under each key is a switch with a metal spring and metal contacts. Thanks to him, the button works even before it is lowered to the end. Using such a keyboard is easy and pleasant - completely different tactile sensations. But the sound when pressing the keys is louder. Service life is about 50 million clicks.

They have keys different types depending on the needs: gaming, for working with text, universal and all sorts of others.

semi-mechanical. Something in between membrane and mechanical. In fact, these are the same membrane ones, but with an extended service life.

Design

The classic keyboard looks simple and unpretentious - a plastic rectangular thing. It comes in different colors, but it is better to choose the standard one: white, black or metallic (gray).

But now you can find other types on sale, for example, rubber keyboards. They look interesting, but in fact they are very inconvenient - the keys are too tight.

There are also all sorts of design options: wooden and even glass. And there are generally “virtual” ones, where the keys are simply drawn with a laser.

By the way, they are very inconvenient to use: even on a perfectly flat surface, the device is constantly “buggy”.

But from the really useful ones, I would single out two types: ergonomic and gaming.

Ergonomic . They have a non-standard curved shape, and some models even consist of two separate parts (which, by the way, is worse). Thus, the keyboard repeats the natural position of the hands and helps to avoid carpal tunnel.

Such a device is simply necessary for those who type a lot of text blindly (with all fingers, without looking at the keys).

Gaming. They have a more convenient key layout for gamers. Plus, they usually have a backlight and additional keys.

What else to look for when choosing

Purpose. Despite the fact that the keyboard is a universal thing, now there are special ones on sale - for laptops, TVs and media players. Actually, they are not much different from the classic ones, but still more convenient for these devices.

Type of printing on keys. This is how the letters and numbers are applied to the buttons. Most often, two types of application are used: conventional printing (90%), laser burning.

In normal printing, the letters appear to be on labels.

With a laser, each character is burned out. They are not erased for a long time, but the inscription is less visible.

In general, there are no problems with the keys now - in almost any computer store you can find special stickers for them. And those for whom this option is not suitable can order an engraving - such a service is also now being provided and is not so expensive. This is especially true for laptops purchased abroad (they do not have Russian letters on them).

Water protection. Such protection is only available for membrane keyboards, and even then not for everyone. Whether it is or not, you can find out from the description of a particular model.

Backlight. Relevant for gaming keyboards. It is in almost every one of them.

Issue price

The price of a standard "tailed" keyboard starts from $3, wireless - from $10. Scissors are more expensive (from $ 15), and mechanical ones are hard to find for less than $ 25. Ergonomic ones are even more expensive.

How to clean your keyboard

It would be nice to do this at least once every couple of months. After all, not only do we usually not wash our hands before working at a computer, but also various dirt and dust get through the cracks between the keys.

It's easy to clean:

1 . Blow out the dirt with a vacuum cleaner (in blowing mode). You can do this with a hair dryer, but only with cold air. If neither is available, simply flip and shake the keyboard.

2. Wipe the keys themselves from above with a cloth slightly moistened with an alcohol-containing solution (you can buy it at a pharmacy). Just do not overdo it: alcohol can accidentally erase the inscriptions on the buttons.

Computer architecture

Keyboard designed to enter information into a computer. The following groups of keys can be distinguished on it:

• main;
• auxiliary;
• a group of cursor keys;
• function key group – .

On main part The keyboard contains alphanumeric keys, and the arrangement of Latin letters on an IBM PC keyboard is usually the same as on an English typewriter, and Cyrillic letters are like on a Russian typewriter.

Often, when working, you have to repeatedly use the same command. To replace the routine work of the user by entering such repetitive commands, function keys -(usually only used F1-F10) at the top of the keyboard. For example, key in all programs is used to call help.

Cursor keys allow you to move the cursor in the desired direction.

Keys , [↓], [←], [→] are used to move the cursor up, down, left, and right, respectively.

Keys , are used to page-by-page move up and down the screen (for example, turning over the text displayed on the screen).

Keys And are designed to move the cursor to the beginning and end of lines, respectively.

Key (delete - delete) is used to delete the character on which the cursor is located. In this case, the cursor itself remains in the same place, and all characters to the right of the cursor are shifted one position to the left.

Key (insert - insert) is designed to switch from insert mode to replace mode and vice versa. In insert mode, the characters you type appear at the location of the cursor, and the portion of the line to the right of the cursor moves one position to the right each time you press the key. In the replace mode, the text located to the right of the cursor is not shifted, and the entered characters appear in place of the old ones, overwriting them.

Auxiliary keyboard usually used when working with programs that have a built-in calculator, as well as when entering large arrays numbers. Numeric keys on the auxiliary part of the keyboard are aligned with the keys , , , , , and cursor keys. In addition, there is also a key , which is used to switch from digital mode to cursor control mode and vice versa. When this key is pressed, the "Num Lock" indicator in the upper right corner of the keyboard lights up, indicating that the keypad is in numeric mode.

Special keyboard keys. In addition to the listed keys, the keyboard has big number special keys. Briefly consider the purpose of these keys.

Key (input) is used to move the cursor to the beginning of the next line. In addition, this key is used to enter commands.

Key is used to enter capital and other characters located in the upper case of the keyboard.

Key depicted with a left arrow above the key . Pressing this key moves the cursor one position to the left and erases the character at that position.

Key (escape - exit, rescue, escape), is located in the upper left corner of the keyboard and serves to cancel actions.

To move the cursor several (usually 4 or 8) positions to the right, you can use the tab key .

In order to increase the number of commands executed using the function keys, the keys are used:

- from English word Control (management);

- from the English word Alternative (alternative).

These keys are the same as the key , are for changing the values ​​of other keys. They are used in combination with other keys, and the program being executed can respond to these combinations in a special way.