Text 4 keyboard

The keyboard is the key control unit of the PC. It is used for input of the alphanumeric (sign) data, and also commands of handle.

You usе the keyboard to type instructions for your computer, and to type information you want your computer to process. All keyboards have letter keys, punctuation keys, and a spacebar. Most keyboards also have function, numeric, and arrow keys, in addition to ALT, CTRL, DEL, and ENTER or RETURN keys.

Their placement on the keyboard is determined by the computer manufacturer; how they are used is determined by the software you are using.

Text 5 Numeric Keypad

Because the number keys are grouped together on the numeric keypad, the keypad is a quick and easy way to type numbers. With many software products, you must press the NUM LOCK key before using the numeric keypad to type numbers. The NUM LOCK key works somewhat like the CAPS LOCK key on your typewriter. When you press the NUM LOCK key on the numeric keypad, the numbers you press on the keypad appear on your screen.

Standard Keyboard

Extended keyboard

Text 6 Arrow Keys

In most cases, the arrow keys help you move around the screen. Like other keys, however, their exact function is determined by the software you are using. On standard keyboards, the arrow keys are on the numeric keypad, along with the numbers. To use these keys properly, the NUM LOCK key must not be active. If NUM LOCK is active, you will type a number instead of changing your position on the screen when you use an arrow key.

On extended keyboards, arrow keys appear to the lower left of the numeric keypad. You can use these arrow keys anytime, regardless of whether the NUM LOCK key is active.

Standard Keyboard

Extended keyboard

Text 7 Function Keys

Function keys send instructions to the software you are using. For example, suppose you are writing a memo and you have trouble moving a paragraph. By pressing a function key, you may be able to get Help information on your screen.

Like other keys, what a function key does depends on the software you are using. For example, some software uses F1 to display Help information, whereas other software uses the F1 key for a different function (or may not assign a function to that key at all).

The function keys are located across the top on extended keyboards or on the left side of standard keyboard.

Standard Keyboard

Extended keyboard

Text 8 additional keys

In addition to the standard numeric, arrow, and function keys, extended keyboard include BACKSPACE, INS, DEL, PAGE UP, PAGE DOWN, HOME and END keys. Typically, you can use the PAGE UP, PAGE DOWN, HOME and END keys to move around or scroll through information on your screen, and you can use the BACKSPACE, INS, and DEL keys to edit text. As with other keys on your keyboard, what these keys do depends on the software you are using.

The additional keys on extended keyboard

Text 9 additional hardware

In addition to the basic components, most computer systems include other hardware, such as a printer, a mouse, and possibly a modem.

Peripheral devices of the PC are connected to its interfaces and intended for execution of auxiliary operations. Due to them the computer system gains flexibility and scalability.

Scanner is the input device for graphic data. It is intended for input of the graphics information on paper.

Printing stations are used to receive copies of documents on paper. By a principle of operation, distinguish matrix, laser, and ink-jet printers. A printer prints the information processed by your computer. Printers vary in printing speed and output capabilities. For example, some letter–quality printers can print high–quality text quickly; some dot matrix and laser printers can print both text and graphics.

Mouse and special manipulators are the devices of command handle. The mouse is the control unit manipulation type. It can’t be used for input sign information – the principle of handle is clicks of buttons and movements.

By using a mouse, you can move a pointer on your screen. You change the position of the pointer by moving the mouse across your table or desktop. You can also use a mouse to select an item by pointing to it and then clicking a button.

Modem is the device intended for information interchange between remote computers. A modem connects your system to a telephone line so that you can communicate with another computer in another building, or even across the country. You can use a modem to receive business information from services like the Dow Jones News Retrieval and CompuServe Information Service.