Type Of Input Devices
An input devices enables you to input information and commands into the computer. If the CPU is the brain of the computer, Then the input devices are ears and eyes. You can interact directly with the input devices but only indirectly with CPU .
The most commonly used input devices are keyboard and mouse many other type of input devices are track ball, track pas, Pointers in the keyboard, Touch Screen, Stylus, Game controls etc...
The Keyboard
A keyboard is the primary input device for entering text and numbers. A relatively simple and standard keyboard includes about 100 keys, each of which sends a different signal to the CPU. The IBM enhanced keyboard has 101 keys, arranged in few groups they are Alpha numeric keys, Modifier keys, Numeric key pad, Functional keys and Special purpose keys and Special purpose keys.
➧ Alphanumeric keys
The part of the key board that looks like a type writer. Keys are arranged in the same way on almost every keyboard. Sometimes this is very common arrangement is called QWERTY layout because the first six keys on the top row elements are Q,W,E,R,T along Y.
Along with keys that produce letters and numbers. The alphanumeric key group includes a few additional keys with special and specified functions.They are TAB, Capslock, Backspace and Enter Keys.
➧ Modifier keys
A keyboard's modifier keys are so named because they are used to modify the input of the other keys. The modifier key are SHIFT,CTRL, ALT.
➧ Numeric Keypad
The numeric keypad is generated located at the right bottom of the keyboard, looks like an adding machine, with its ten digits and mathematical operators. The numeric keypad is also features a numlock, to force the numeric keys to input numbers.
When NumLock deactivated the numeric keypad's keys perform cursor movement control and other functions. The keys 2,4,6,8 keys are also known as cursor movement keys in the directions down,left,right, up respectively.
➧ Function Keys
The Function keys are usually arranged along the top of the keyboard. They allows the input commands without by using the typing a long strings of characters. Each functions keys purpose depends upon the program/application are using.
➧ Special Purpose Keys
In addition to these, there are some keys, each of which perform a specialized function. They are Insert, Delete, Esc, Print Screen, Scroll Lock, Pause, Home, End, Page Up and Page Down.
The Mouse
A mouse is an input device that rolls around on the flat surface and controls all the pointers.The pointer is an on-screen object,usually an arrow that is used to select text,access menus,and interact with programs,files,or data that appear on the screen.The pointer looks like:
Advantages of Mouse:
1.The advantage of the mouse are so numerous that it changed the entire personal computing industry.
2.Instead of forcing you to type or issue commands from the keyboard,the mouse and mouse based operating systems let you choose of remembering obscure(meaning less)command names,users can figure out where commands and options are located.
3.A mouse can also allows you to create graphics such as lines,curves,and freehand shapes on the screen.
The Trackball
A Trackball is a pointing device that works like an upside down mouse.To move the pointer around the screen you roll the ball with your thumb.Because you don't move the whole device a trackball requires less space then the mouse.Most trackballs features two buttons with right and left hand model.
The Trackpad
The trackpad is a stationary pointing device that many people find less tiring to use than the mouse or trackball .The movement of a finger across a small touch surface is translated into pointer movement on the computer screen.The trackpad's size makes suitable for a notebook computer. Trackpads are usually separate from the keyboard in the desktop computers and are attach the same functions as mouse functions as mouse buttons.One drawback of trackpad is that they must be kept clean and static free.
Touch Screen
Touch screens accept input by allowing the user to place a fingertip directly on the computer screen.Usually to make a selection from menu of choices.Most touch screen computers use sensors in or near the computer's screen to detect the touch of a finger.They are well suited for simple applications such as automated teller machines or public information centres,department stores,and drug stores and supermarkets.
Styles
Pen-based systems including many personal digital assistants and other type of hand held computers.Use a 'pen' for data input.This pen-like device is sometimes called a styles.You hold the pen in your hand and write on a special pad or directly on the screen.You can also use the pen as a pointing device,like a mouse to select the commands.
Pen-based systems are more commonly used for data collection,where the touch of a pen might select a yes or no box or mark a box next to a part that must be ordered or a service that has been requested. Another common use is inputting signatures or messages that are stored in the transmitted as a graphic image.
Game Controllers
Game controllers generally fall into two categories:game pads and joysticks.Joysticks can be used with applications other than games. Joysticks enable the user to "fly" or "drive" through a game, directing a vehicle or character.They are popular in racing and flying games.A varient of the joystick is the game controller,which includes an actual steering wheel.
The Keyboard
A keyboard is the primary input device for entering text and numbers. A relatively simple and standard keyboard includes about 100 keys, each of which sends a different signal to the CPU. The IBM enhanced keyboard has 101 keys, arranged in few groups they are Alpha numeric keys, Modifier keys, Numeric key pad, Functional keys and Special purpose keys and Special purpose keys.
➧ Alphanumeric keys
The part of the key board that looks like a type writer. Keys are arranged in the same way on almost every keyboard. Sometimes this is very common arrangement is called QWERTY layout because the first six keys on the top row elements are Q,W,E,R,T along Y.
Along with keys that produce letters and numbers. The alphanumeric key group includes a few additional keys with special and specified functions.They are TAB, Capslock, Backspace and Enter Keys.
➧ Modifier keys
A keyboard's modifier keys are so named because they are used to modify the input of the other keys. The modifier key are SHIFT,CTRL, ALT.
➧ Numeric Keypad
The numeric keypad is generated located at the right bottom of the keyboard, looks like an adding machine, with its ten digits and mathematical operators. The numeric keypad is also features a numlock, to force the numeric keys to input numbers.
When NumLock deactivated the numeric keypad's keys perform cursor movement control and other functions. The keys 2,4,6,8 keys are also known as cursor movement keys in the directions down,left,right, up respectively.
➧ Function Keys
The Function keys are usually arranged along the top of the keyboard. They allows the input commands without by using the typing a long strings of characters. Each functions keys purpose depends upon the program/application are using.
➧ Special Purpose Keys
In addition to these, there are some keys, each of which perform a specialized function. They are Insert, Delete, Esc, Print Screen, Scroll Lock, Pause, Home, End, Page Up and Page Down.
The Mouse
A mouse is an input device that rolls around on the flat surface and controls all the pointers.The pointer is an on-screen object,usually an arrow that is used to select text,access menus,and interact with programs,files,or data that appear on the screen.The pointer looks like:
Advantages of Mouse:
1.The advantage of the mouse are so numerous that it changed the entire personal computing industry.
2.Instead of forcing you to type or issue commands from the keyboard,the mouse and mouse based operating systems let you choose of remembering obscure(meaning less)command names,users can figure out where commands and options are located.
3.A mouse can also allows you to create graphics such as lines,curves,and freehand shapes on the screen.
The Trackball
A Trackball is a pointing device that works like an upside down mouse.To move the pointer around the screen you roll the ball with your thumb.Because you don't move the whole device a trackball requires less space then the mouse.Most trackballs features two buttons with right and left hand model.
The Trackpad
The trackpad is a stationary pointing device that many people find less tiring to use than the mouse or trackball .The movement of a finger across a small touch surface is translated into pointer movement on the computer screen.The trackpad's size makes suitable for a notebook computer. Trackpads are usually separate from the keyboard in the desktop computers and are attach the same functions as mouse functions as mouse buttons.One drawback of trackpad is that they must be kept clean and static free.
Touch Screen
Touch screens accept input by allowing the user to place a fingertip directly on the computer screen.Usually to make a selection from menu of choices.Most touch screen computers use sensors in or near the computer's screen to detect the touch of a finger.They are well suited for simple applications such as automated teller machines or public information centres,department stores,and drug stores and supermarkets.
Styles
Pen-based systems including many personal digital assistants and other type of hand held computers.Use a 'pen' for data input.This pen-like device is sometimes called a styles.You hold the pen in your hand and write on a special pad or directly on the screen.You can also use the pen as a pointing device,like a mouse to select the commands.
Pen-based systems are more commonly used for data collection,where the touch of a pen might select a yes or no box or mark a box next to a part that must be ordered or a service that has been requested. Another common use is inputting signatures or messages that are stored in the transmitted as a graphic image.
Game Controllers
Game controllers generally fall into two categories:game pads and joysticks.Joysticks can be used with applications other than games. Joysticks enable the user to "fly" or "drive" through a game, directing a vehicle or character.They are popular in racing and flying games.A varient of the joystick is the game controller,which includes an actual steering wheel.
