II. Match the definitions with the names of keys.

Arrows keys, Return, Caps Lock, Shift, Tab, Escape, Space bar, Backspace, Alt

1. A long key at the bottom of the keyboard. Each time it is pressed, it produces a blank space.

2. It moves the cursor to the beginning of a new line. It is also used to confirm commands.

3. It stops a program without losing the information from the main memory. Sometimes its use depends of the applications.

4. It works in combination with other keys to produce special characters or specific actions.

5. It removes the character on the left of the cursor or any selected text.

6. It produces UPPER-CASE characters (or the upper-case character of the key).

7. It produces upper-case letters, but it doesn’t affect numbers and symbols.

8. It moves the cursor horizontally to the right for a fixed number of spaces (in tabulations and data fields).

9. They are used to move the cursor as an alternative to the mouse.

Read the text and answer the questions:

1. What is the main function of the input unit?

2. What is the typical layout for most of keyboards?

3. What are function keys used for?

4. What keys are defined as special control keys?

Keyboards are the most widely used input devices. Keyboards for personal computers have several common characteristics; however, there is no standard layout for keyboards. On most of them, you will find the following:

In the center of the keyboard is a typewriter layout for traditional entry of text and special characters. The most common layout is called QWERTY, named for the six leftmost characters in the top row of alphabetic characters. There are alternative layouts that are considered more efficient, but the QWERTY layout has the advantage of familiarity. For the novice, such as a child who has never learned to type, keyboards are often laid out with the keys in alphabetic order to make them easier to find.

A computer keyboard needs more keys than the typewriter layout, and these are generally found surrounding the typewriter keyboard area. In addition to a numeric keypad, you will find (1) function keys; (2) special keys labeled [Ctrl] Control, [Alt] Alternate, [Esc] Escape, [Del] Delete, and [Enter] or [Return]; and (3) four cursor move­ment keys to move the cursor up, down, left, and right.

Function keys are labeled with the characters [Fl] through [F10] or [F12]. The idea behind function keys is to simplify the use of application programs. For example, word-processing software often uses the function keys to perform special commands, such as boldface, underline, or delete a sentence or a paragraph. Pressing the [Fl] key brings up a help system in many applications. A potential drawback is that each application program uses the given set of function keys differently. To compensate for this, either the application program displays the meaning of the function keys on the display screen. Function keys can be used in conjunction with other keys. By combining the function keys with the [Ctrl], Shift, and [Alt] keys, up to 36 functions can be performed.

Special Control Keys

The Delete key [Del] is used to erase character by character. In some applications it can be used to erase a selected block of characters, such as a word, a sentence, a paragraph etc. The Escape key [Esc] is usually used to move from one mode of operation to another. For example, if you have instructed your word-processing software to print a document and discover that you need some corrections, you may be able to press the [Esc] key to stop the printing, correct the mistake, and then continue. However, different applications might have other uses for the [Esc] key.

The [Enter] key, sometimes called the [Return] key, fulfills two functions depending on the program with which it is used. The [Enter] key functions as a signal to continue in most programs. Pressing the [Enter] key also positions the cursor at the beginning of the next line, it is used to establish new paragraphs.

The Control key [Ctrl] is always used in conjunction with one or two other keys to give instructions to a program. For example, when using a word processor, pressing the D key causes the character D to appear on the screen. If you hold down the [Ctrl] key while pressing the D key, the word processor might interpret the combination as an instruction to delete a character. The [Alt] key is used in the same manner.

The specific instructions that are implemented through the use of control keys are defined by individual programs. Like function keys, each application program uses the control keys differently. Control keys in conjunction with other keys enable you to perform complex operations with a minimal number of keystrokes.

Cursor Movement Keys

Moving the cursor around on the screen is one of the most common tasks in an application program. A cursor is a visual aid on a display screen. It may take the shape of a blinking box or underline, an arrow, or even a pointing finger. In word processing, for example, the cursor often blinks on and off and marks the location where the next character will appear on the screen. You can move a cursor to any position - the screen by pressing the cursor movement keys, which are labeled with arrows. These keys can move the cursor up, down, left, or right.