input device keyboard

                                                                                          Complete Notes

Input Devices

Input is any data or instructions entered into the memory of a computer.

An input device is any hardware device that allows user to enter data and instructions into a computer.  

Types of Input Devices

1.     Keyboard

2.     Mouse

3.     Joystick

4.     Scanner

5.     Bar code Reader

6.     OCR

7.     OMR

8.     Web Camera

1. Keyboard

Keyboard is the most common and very popular input device which helps to input data to the computer. 

A keyboard contains keys that allow a user to enter data and instructions into the computer.

Keyboards are of two sizes 84 keys or 101/102 keys, but now keyboards with 104 keys or 108 keys are also available for Windows and Internet.

Types of Keyboard

1.     Alpha Numeric Keys

2.     Numeric Keys

3.     Function Keys

4.     Control keys

5.     Cursor Movement Keys

6.     Special Purpose Keys

 

1.     Alpha Numeric Keys: Alpha Numeric keys are the Collection of alphabets [a-z], Numerals (0-9), Punctuations marks. The Alpha Numeric keys also have modifier keys such as SHIFT, ctrl (Control), alt (Alternate).They are used with other Keys.

2.     Numeric Keys: It is located on the right side of keyboard and appears like non-scientific calculator. It has ten digits (0-9) and the arithmetic operators (+,-,*, /).

3.     Function Keys:  It is located at the first row of the keyboard. The function keys are numbered from f1 to f12.Each function key has a unique meaning and is used for some specific purpose.

4.     Control keys: These keys provide cursor and screen control. It includes four directional arrow keys. Control keys also include Home, End, Insert, Delete, Page Up, Page Down, Control(Ctrl), Alternate(Alt), Escape(Esc).

5.     Cursor Movement Keys: These keys help to change the position of the cursor on the screen.

6.     Special Purpose Keys: Keyboard also contains some special purpose keys such as Enter, Shift, Caps Lock, Num Lock, Space bar, Tab, and Print Screen.

Advantages of keyboards

·        Most computers come with a keyboard supplied.

·        People are used to using keyboards to enter data, they need very little training.

·        A skilled typist can enter data very quickly.

Disadvantages of keyboards

·        It is easy to make mistakes when typing in data.

·        Keyboards are not suitable for creating diagrams

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