Summary Of Input Devices 715i3g

SUMMMARY OF INPUT DEVICE

INPUT DEVICE  Input device is a device which feeds data and information into the computer.

Types of input devices Keyboard  The keyboard has keys for alphabetical characters and extra keys for special functions

Numeric keyboards  They have keys to input numbers and a few special keys

QWERTY keyboards

 It gets its name from the first row of keys. It is most commonly used.

Advantage  Many people know how to use a QWERTY keyboard. So help is available.

Disadvantage  To use a keyboard efficiently you need to know the layout and be able to touch type.

Pointing devices Mouse  It is the most widely used pointing device and some have a ball underneath and some have a light which detects the movement using the light.

Joystick  It is mostly used for games ad and to control cranes. There are simply two levers which are used to control and some buttons.

Tracker ball  It is like an upside down mouse because the ball is on top and you need to use your thumb or finger to roll the ball.

Graphics tablet

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 It is a flat rectangular pad between 6 and 30 inches wide. It works with a stylus which you need to move along the surface to produce drawings.

Advantage  People find it easier to use to point and click than typing.

Disadvantage  It is harder to input text

Scanners  Scanner is an input device that captures hard copy and converts it to soft copy.

Advantage  They quickly convert printed images on paper to electronic form.

Disadvantage  The accuracy of data input is unlikely to be verified.

OMR (Optical Mark Recognition) An OMR technology is used to interpret pencil marks in a piece of paper.

Advantages  There is no requirement to type in the information written on paper form. Because of this input is faster and less expensive.

Disadvantages  OMR forms must be printed very carefully because the position of the mark on the paper affects the accuracy of the input. Because of this, printing costs more.

OCR (Optical Character Recognition)  OCR is the identification of printed or written text characters by a computer.

Advantages  Text printed can be converted to electronic form and edited.

Disadvantages  Character recognition is not always accurate and the electronic text has to be checked carefully.

Magnetic Stripe Card  A magnetic swipe card reads information from a magnetic stripe on the surface of a plastic card when it is swiped through the reader.  They can be used to control access to buildings. For example to gain access to a building or to leave it, a stripe card is ed through a reader that controls whether a door opens or closes. If the identification on the card is recognizing by the ICT system it will open if not it will remain closed.

Advantages  They are often used as a form of identification that is small and light and can be carried at all times.  The data recorded on the card is in electronic form and can be inputted into computer directly.

Disadvantages  The data recorded on the magnetic stripe card can be affected by magnetic radiation, such as that from TV’s and computers.  It can be copied and edited. This is an opportunity for determined criminals to commit identity theft and fraud

Smart Cards  A smart card is similar in shape and size to a magnetic card, but has a microprocessor chip embedded in it. The chip can do some processing as well as storing information. Special devices can communicate with the chip to read and write information on the card. Security features can be programmed in to the chip.

Advantages  Often used as a form of identification that is small and light and can be carried at all times.  The data recorded on the chip is in electronic form and can be input directly into a computer.

Disadvantages  The data recorded on the chip can be copied and edited by very determined criminals and used for fraud.

 The data recorded on the chip can be affected by electromagnetic radiation: for example, form television and computers.

Biometric scanners  Biometric scanners are a pattern of recognition system which makes personal identification based on a person’s unique physical characteristics. Biometric scanners use face recognition, finger print matching, iris / retinal scans, voice recognition, and hand geometry.

Advantages  There is no need to carry personal identification.  The person has to be present. This makes identification theft and fraud much less likely.

Disadvantages  Identification using biometric scanner is not yet sufficiently accurate. Permitted s will not be recognized at times, and blocked s will sometimes be permitted.

Sensors

 Sensors are used to input the data about the environment into a computer. They are available in many different shapes and sizes, and they have a wide variety of uses. For example, sensors can be used to record light intensity, temperature and pressure.

Advantages  They can be placed in dangerous locations where people would be hurt.  Sensors can record data that people do not sense or do not sense accurately such as humidity.  The data recorded by sensors can be automatically recorded in a form that can be processed by a computer.

Disadvantages  They cannot interpret the data.  They detect a very restricted range of the different types of data.