The keyboard was one of the first peripherals to be used with computers, and it is
still the primary input device for entering text and numbers.
A standard keyboard
includes about 100 keys; each key sends a different signal to the CPU.
If you have not used a computer keyboard or a typewriter, you will learn
quickly that you can use a computer much more effectively if you know how to
type. The skill of typing, or keyboarding, is the ability to enter text and numbers
with skill and accuracy. Certainly, you can use a computer without having good
typing skills. Some people claim that when computers can interpret handwriting
and speech with 100 percent accuracy, typing will become unnecessary. But for
now and the foreseeable future, keyboarding remains the most common way to
enter text and other data into a computer:
The Standard Keyboard Layout
Keyboards come in many styles. The various models differ in size, shape, and feel;
except for a few special-purpose keys, most keyboards are laid out almost identically. Among IBM-compatible computers, the most common keyboard layout is
the IBM Enhanced Keyboard. It has about 100 keys arranged in five groups, as
shown in Fig. 1. (The term IBM-compatible computer refers to any PC
based on the first personal computers, which were made by IBM . Today, an IBM compatible PC is any PC other than a Macintosh computer.)
Fig. 1: Standard keyboard layout.
The Alphanumeric Keys
The alphanumeric keys—(the area of the keyboard that looks like a typewriter's
keys—are arranged the same way on almost every keyboard. Sometimes this common arrangement is called the QWERTY (pronounced KWER-tee) layout because the first six keys on the top row of letters are Q, W, E, R, T, and Y.
Along with the keys that produce letters and numbers, the alphanumeric key
group includes four keys having specific functions. The TAB, CAPS LOCK, BACKSPACE, and ENTER keys are described in Fig. 2.
Fig. 2: The Alphanumeric Keys.
The Modifier Keys
The SHIFT, ALT (Alternate), and CTRL (Control) keys are called modifier keys because they modify the input of other keys.
In other words, if you hold down a
modifier key while pressing another key, then you are changing the second key's input in some way. For example, if you press the J. key, you input a small letter j.
But if you hold down the shut key while pressing the J key, you input a capital J.
Modifier keys are extremely useful because they give all other keys multiple capabilities. Fig. 3 describes the modifier keys and their uses.
Fig. 3: The Modifier Keys.
The Numeric Keypad
The numeric keypad is usually located on the right side of the keyboard, as shown
in Fig. 4. The numeric keypad looks like a calculator's keypad, with its 10
digits and mathematical operators (+, -, *, and /). The numeric keypad also features a NUM
LOCK key, which forces the numeric keys to input numbers. When NUM LOCK is deactivated,
the numeric keypad's keys perform cursor movement control and other functions.
Fig. 4: The Numeric Keypad.
The Function Keys
The function keys, which are labeled F1, F2, and so on (as shown in Fig. 5), are usually arranged in a row along the top of the keyboard. They allow you to input commands
without typing long strings of characters or
navigating menus or dialog boxes. Each function key's purpose depends on the program
you are using. For example, in most programs,
F1 is the help key. When you press it, a special
window appears to display information about the program you are using. Most IBM-compatible keyboards have 12 function keys. Many programs use function keys along with modifier keys to give the function keys more capabilities.
Fig. 5: The Function Keys.
The Cursor-Movement Keys
Most standard keyboards also include a set of cursor-movement keys, which let
you move around the screen without using a mouse. In many programs and operating systems, a mark on the screen indicates where the characters you type will
be entered. This mark, called the cursor or insertion point, appears on the screen
as a blinking vertical line, a small box, or some other symbol to show your place
in a document or command line. Fig. 6 describes the cursor-movement keys.
Fig. 6: The Cursor-Movement Keys.
In addition to the five groups of keys described earlier, all IBM-compatible keyboards feature six special-purpose keys, each of which performs a unique function. Fig. 7 describes these special-purpose keys.
Fig. 7: Special-Purpose Keys.
Since 1996, nearly all IBM-compatible keyboards have included two additional
special-purpose key's designed to work with the Windows operating systems:
. This key, which features the Windows logo (and is sometimes called
the Windows logo key), opens the Windows Start menu on most computers.
Pressing this key is the same as clicking the Start button on the Windows
. This key, which features an image of a menu, opens an on-screen
shortcut menu in Windows-based application programs.
One of the latest trends in keyboard technology is the addition of Internet and
multimedia controls. Microsoft's Internet Keyboard
and Multimedia Keyboard
for example, feature buttons that you can program to perform any number of
tasks. For example, you can use the buttons to launch a Web browser, check e-mail, and start your most frequently used programs. Multimedia buttons let you control
the computer’s CD-ROM or DVD drive and adjust the speaker volume. Many keyboard makers offer such features on newer models (see Fig. 8).
Fig. 8: Email key on keyboard.
Do you want to say or ask something?