Direct data entry devices and their advantages and ...

[Pages:10]Chapter 2, table of contents

01 Input devices and their advantages and disadvantages. 02 Direct data entry devices and their advantages and disadvantages. 03 Output devices and their advantages and disadvantages.

Input Devices

Keyboard

Used to enter text into Designed for long-term Data cn only be input

a computer.

repetitive use and

as fast as it can be

widely available.

typed.

Numeric keypad

Used where numerical Simple to use. information needs to

be entered

Limited to numerical data only.

Mouse

Used to control the position of the pointer on the screen.

Touch pad An alternative to a

mouse.

Directly transfer physical movement into the computer system.

Removes the need for a separate mouse.

Requires a flat surface on which to work.

Requires fine finger control.

Tracker ball An alternative to a

mouse

Requires very little space to operate.

The tracker ball is often removable and can be lost.

Remote controls Scanners

Joysticks

Held in the hand and used to control TVs, PCs, home entertainment systems.

Allow hard copies of images or text to be transferred to a computer.

Used to control objects on a screen in computer games.

Steering wheel

Virtual simulators to steer a vehicle.

Devices can be controlled from a short distance.

Images can be scanned at very high resolution.

Easy to use as there are few buttons.

Just like in a real vehicle.

Touch screens

Removes the need for a keyboard, allowing a user simply to choose options on screen.

Screen can be cleared easily.

Device can be difficult to use if remote control is lost.

High resolution scanning produces large file size.

Limited to directional control.

Limited to driving applications due to limited movement.

More expensive than a standard display.

Digitl camera

Used to take high quality photographs that can be viewed immediately a display.

Microphones Used to input sounds

and voices.

Temperature Used to input

Sensor

temperature readings to a computer.

Pressure sensor

Used to input pressure readings to a computer.

Light sensor Used to input light

readings to a computer.

Images resolution very high.

Extremely common and inexpensive.

More accurate than traditional thermometers.

More accurate than traditional weighing devices.

Able to detect very small changes in light levels.

The higher the resolution, the more memory is needed to store it.

Digital audio files can take up a lot of space.

An additional analogue to digital convertor is required to input the signal into a computer to process. Any object of suitable weight can incorrectly activate them.

An ADC converter is required.

Video camera

Capture and store moving images.

Webcams

Capture still and moving images

Graphics tablet

Used to input freehand drawings.

Light pens Used to draw onto a

computer display.

Sound and video are recorded at the same time.

Allow people to chat face to face.

Can be used to input much more natural drawings than can be achieved with a mouse. Precise inputs

Takes a lot of computer storage space.

Often use lower resolution .

Requires space and practice to use.

Requires practice.

Direct data entry devices

Magnetic stripe readers

Used to read data from magnetic stripes on identity and banking cards.

Chip readers

Used to read data from chips on bank cards.

PIN pads

Used to enter data into ATM machines.

RFID reader

Used to enter data into ATM machines.

Magnetic Ink Character reader

Used to enter data from bank cheques.

Information can be input into a system quickly.

More secure than magnetic stripe systems.

PIN codes help to prevent unauthorized access.

PIN codes help to prevent unauthorized access.

Information can be read very quickly.

Very limited storage capacity in the stripes.

Not as widely available as magnetic stripe readers.

People can be seen entering the PIN code.

People can be seen entering the PIN code.

Expensive.

Direct data entry devices

Optical mark reader OMR

Used to read and input information from a form or test paper.

Optical Character Reader OCR

Used to transfer handwritten into text.

Whole page of information can be read quickly.

Much quicker than manually retyping information.

Barcode reader

Used to scan identification codes.

Much quicker than manually retyping information.

Incorrect completed forms can result in error.

Handwriting must be neat and legible.

Barcode can become easily damaged and unreadable.

Output devices and their advantages and disadvantages

Cathode Ray Tube CRT Monitor

Thin Film Transistor TFT/LCD Monitor

Present text and graphics..

Used in home and office nowadays.

Bright, clear display Lighter and thinner.

Large and heavy Can be damaged easily.

In Plane Switching IPS/LCD monitor

IPS is a screen technology used in modern LCD monitors, mobile phones, and tablets.

Color reproduction is much more consistent.

Expensive.

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