Input Devices

Input devices

Chapter 3

The ‘Ins’ and ‘Outs’ of systems

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Input devices are used to get data into a system

For e.g. : a mouse

a keyboard

Definition:

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The ideal input device would be able to get data into a system as accurately as possible, in the least amount of time without human help.

The device would be pretty cheap.

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The is no such input device and the choice is always the same.

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KeyboardsThere are different types of keyboards

For e.g. : - ergonomics (concept keyboards)

- normal keyboard (everyday use)

- Braille keyboard for the disabled

- large key color coded, for visually impaired

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Mouse

Mouse is used to control the cursor that activates programs in the operating system.

Types of mouse: - tracker ball

- optical

- synoptic touchpad laptop

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JOYSTICK

Similar to a tracker ball, but it is mainly used in games, but can also be used as in scanners in hospitals.

LIGHT PEN

The screen cursor can be move by touching the screen with the pen.

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TRACKER BALL

The turns a ball to move the cursor but mouse itself is always still.

TOUCH SENSITIVE PADS

Also known nowadays as the synoptic touch pads. Uses your finger to move the cursor and acts as pressure pad for selections. Used on laptops

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It is a special screen, when touch with the finger it gives commands just like a light pen.

TOUCH SCREEN

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Graphic Tablets

Like an electronic tracing paper used for graphic designing.

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Magnetic stripe reader

Used to read credit and debit cards. Often called EPOS (electronic point of

sale.)

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Barcode Readers

Used in supermarkets, library systems, luggage handling

Record from meters or more.

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Optical character readers and Optical character recognition (OCR)

Inputting text using a scanner then turning them into ASCII code, not picture but edited as word document.

Cannot distinguish between certain character and numbers: S and 5 or B and 8

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Magnetic character reader & optical character recognition (MKR)

Strange numbers at the bottom of checques.

Iron added to make ink magnetic. Read through a special reader called

magnetic ink character readers. Account number, branch code, checque

number= magnetic ink

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Optical mark readers and optical mark recognition [OMR]

Sense marks made on certain places on special sheet.

Answer sheet marking, capturing data from questionnaires MCD’s

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Optical mark readers and optical mark recognition [OMR]

ADVANTAGE Does not have to be

types in Reduce cost of

inputting Results of tests are

needed very fast.

DISADVANTAGE Public don’t follow

instruction Creased or folded

forms have to be done manually, machines rejects it.

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Punched cards

Punched cards = Before keyboards Reads through notes Stock record

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Kimball Tags

Tagged to clothing for payment.

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Voice recognition Speaks directly with computer Useful to handicaps with limited movement Uses microphone

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Microphone Speech recognition system Voice mail Record voice

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Electronic point of sale Cash registers Act as terminal to main computer system Useful management system

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Electronic fund transfer at point of sale (EFTPOS)

Transfer funds from your bank account to stores account using debit cards

Debit card – fast method of payment

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Video digitizer Combination of hardware and software that

converts analogue signal into digital signal. Taking a video frame and digitizing it is also

called image grabbing. Examples are: magazines or pop videos

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Scanner Used to scan text or pictures. Scan photos that can be used in desktop

publishing. Example is the OCR.

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Digital cameras Takes digital photos and does not need any

film. Pictures can be resized and cropped to as

precise as possible. They are saved into the HDD. No picture developing Cost. One time

investment.

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Web camera also known as WEBCAMS.

Used to capture images and videos. Helps in video conferencing. The quality of the camera is very bad

therefore the pictures will not be very good.

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Advertising

Cruise companies place them in ships so that potential customers can see what is going on inside the ship at a particular time.

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Checking the weather in another part of the world.

You can see how the weather is in another part of the world through a webcam by just watching the pictures broadcasted by another web cam somewhere else.

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Touch tone telephones. They have a different number for each

number pressed. Can be used as data entry device. Once connected the customer can use its

services, such as statement requests.