How to Maintain Input Devices

input hardware is classified as keyboard entry or direct entry.
input hardware :consists of devise that take data and programs that  people can read or comprehend and convert them to a from the computer can process.The people -readable from may be works like the ones in the sentences ,but the computer -readable from consists of 0s and 1s, or off and on single.
      Input devise are of two types : keyboard entry and direct entry.(see figure2.1)
 In a computer , a keyboard  is a device that convert letters, numbers and other characters into electrical singles that are machine - readable by the computers processor.The keyboard may look like a typewriter keyboard to which some special keys have been added.Or it may look like the keys on a bank's automatic teller machine or the keypad of a pocket computer used by a bread-truck driver.
     Direct-entry device : refers to the many forms of data-entry devices that are not keyboards .Direct entry devices create machine-readable data on magnetic media or paper or feed it directly into the computers processor .Direct-entry devices include the following :

• Pointing devices
• Scanning devices
• Smart cards devices
• Voices -recognition optical cards
• Audio -input devices
• Video-input devices
• Electronic cameras
• Sensors
• Human -biology input devices

              Often keyboard and direct -entry input devices are combined in a single computer system.A desktop-publishing system , for example , use a keyboard , a mouse , and an image scanner.