INPUT DEVICES

INPUT DEVICES

The process of entering data and instructions (programs) into the computer system. The common input devices are Key Board, Mouse, Joysticks, Scanner, and Light Pen etc.

1.         KEY BOARD: -

        Data and instructions required for the C.P.U are provided through the keyboard. The keyboard layout is similar a typewriter with some additional keys. They are classified as 1- Function Keys 2. Alpha Numeric Keys, 3. Cursor Movements Keys (Left, Right, Up, Down arrows keys) and 4. Editing and Special Keys (Home, End Shift, Alt, etc). Each key, when pressed produces and equivalent binary code that is mapped into a table and the corresponding Character’s is displayed.

Some Keys and the Functions they Perform are:-

KEYS	FUNCTIONS
F1-F12	Functions Keys - these perform special functions, which we will learn in due course
Enter (or) Return Key	Used to communicate the end of an instructions or data being keyed in through the keyboard.
Caps Lock	For keying in Capitalized Alphabets
Shift key	Provided caps lock is OFF if pressed simultaneously with a character key, a capitalized alphabets in is input. If caps lock is ON, it reverses the effect of caps lock. Also used to input the upper symbols for keys with two symbols or characters on them.
CTRL, ALT, keys	Pressed with other keys, input special massages to the computer.
Backspace Key	Used to Erase (Remove) character to the left of cursor position.
Num Lock key	Used to activate the numeric keys on the Numeric keypad
Cursor keys (Arrows Keys)	Used to move the cursor in the direction indicated.
Home, End, Pg Up, Pg Dn	Perform special functions which we will gain familiarity with during the course
Insert Key	Used to insert characters at the current cursor position
Del key	Used to delete characters Right side at the current cursor position. Also delete selected files
ESC Key (or)                          Cancellation Key	Depends on the application. Usually used to return to the previous menu of the applications
Scroll Lock	Used to activate or de - activate scrolling of the text on the screen.
Space Key	This key is used to give space between words.
Print Screen	Used to print what ever is Display on the Screen

Key Symbols with Name as Follows:

KEYS SYMBOL	NAME
?	Question Mark
{	Open Flower Bracket
}	Closing Flower Bracket
[	Open Square Bracket
]	Closing Square Bracket
“  ”	Quotation (Quotient)
.	Dot
(‘) or ‘’	Apostrophe
,	Comma
;	Semi colon
:	Colon
|	Pipe
\	Back Slash
/	Forward Slash
~	Tilde
!	Exclamation
@	At the rate of
#	Hash
=	Equal to
$	Dollar