Input and OutputGina 10A

Input

Input devices allow us to enter raw data into a computer.

The computer processes the data and then produces

outputs that we can understand using an output device.

The processing is mainly handled by the CPU.

2 types of Input:

Manual

Automatic

Manual Input Devices

Keyboard

Made up of buttons, “Keys”.

“QWERTY” is another word for keyboard. Come from the first 6 letters on the top row of the alphabet keys.

Alphanumeric Keyboard

Allows:

text (abc…)

number (123…)

Symbols (@#$...)

Numeric Keypad

Small keyboard

Only have numbers

Enter numeric data into ATM

PIN Pad

Enter Personal Identity Number (PIN)

Electronic door locks.

Mouse

Pointing device

Sensors on the bottom of the mouse detect when the mouse is moved.

Optical or wireless technology to track mouse movement.

control by GUI

Touchpad/Trackpad

On laptops

Take up less space

Use by fingers

Control by GUI

Trackball/Tracker Ball

Pointing device

Large ball that user spins.

Control by GUI pointer

Limited movement (disabled)

Very young, easier to use than a mouse

Touch screen

Touching the surface

Very intuitive and simple to use.

Information terminals in public places e.g museums.

Graphics Tablet

Pointing device

Used by designers and artists.

Allows natural hand movements.

Input to graphicsapplication.

Hand-drawn sketches

Joystick/ Joypad

Playing games

Small joysticks can be found on some mobile phones.

Light Pen

Pointing device

Write on screen

Rarely used

Scanner

Scans images, etc.

Taking close-up photograph

Most common scanner is Flat-bed.

Digital Camera

Digital photographs

Store on memory cards.

Transferred to a computer.

10 Megapixels

Video Camera

Stored on video-tape or memory cards.

Later transferred to a computer.

Television production

Web Cam

Very basic video camera

Live video into computer

Low quality

For web chats

Microphone

Converts sound into a signal

Analogue

ADC: Analogue Digital Convertor

Automatic Input Devices

Magnetic Strip Reader

Strip of material that can be magnetised on the back.

Data stored in the form of magnetised dots.

Data stored on the strip

Data shown on the front of the card.

Faster and more accurately

Swiping the card through a slot.

Smart Card/Chip Reader

Chip of computer memory

Smart cards

Data stored in this memory and read back using a chip reader.

Connect to metal pads

The reader can access the memory chip and data stored.

MICR Reader

Magnetic Ink Character Recognition

Bank cheques

Quickly & accurately

Cheque number & bank account number are printed at the bottom of the bank cheque.

Special magnetic Ink, special front

MICR reader

OMR Scanner

Optical Mark Recognition

read quickly & accurately

Special OMR forms can be coloured in.

Marks then detected by OMR scanner.

Multiple-choice exam answer sheets & lottery number forms.

OCR Scanner

Optical Character recognition

Convert images of text into an actual text file

Scanned, scanned image then analysed by OCR software.

Letter shapes

handwriting or handwriting recognition

Barcode Reader/Scanner

Numeric code

Series of lines

Barcode reader/scanner

Point-of-Scale (POS)

Code

Read barcode, quick & accurate than typing.

Sensors

Senses (5 senses)

Converts a real-world property into data that computer can process.

Analogue signal converted into digital data for computer.

Analogue-to-Digital-Converter (ADC)

Use: monitoring, measuring, data logging systems & computer control systems.

Remote Control

Send data signal by button.

Infrared light or radio signals

Control a computer from some distance.

Control a presentation slideshow.

Output

CRT Monitor

Displays text & image

Cathode-ray tube (CRT)

Large & boxy

A lot of desk space.

Replaced by flat-screen monitors.

Accuracy & brightness

Flat-Screen Monitor (TFT or

LCD)

Replaced CRT monitors

Light in weight

Little desk space

Picture quality

Digital/Multimedia Projector

Very large viewing area e.g.: presentations for advertising or watching movies.

DVD player

Satellite receiver

Powerful light source

Loudspeaker

Music or sounds

Convert electrical signals into sound waves

Music editing, video conferencing, watching movie.

Dot Matrix Printer

Tiny pins

Leaves a pattern of dots. Can form letters, images, etc.

Continuous stationary

Quality is poor

Noisy

Carbon-copies e.g. airline tickets

Duplicate pages all printed in one go.

Very cheap

Last for a long time e.g. shop receipts.

InkJet Printer

Cheap, High-quality

Full-colour

Squirts tiny droplets

Full-colour

Tiny holes: jets

Perfect for photographs

Very quite

Cheap to manufacture

Ink is very expensive

Expensive to use

Laser Printer

Very complex

Expensive to buy

Very cheap to use

Marks on paper >> toner

Complex system, laser

Very fast printing

Very common use in offices

Plotter

Draw on paper using a pen

Accurately & quickly

Different coloured pens

Used by designers & architects

Huge pieces of paper

Motor

Movement

In washing machine, microwave & air conditioning units.

Switched on & off

Pumps

Push water

Air along pipes

Part of watering systemsin greenhouses, in factories.

Buzzer

Provide noise

In microwave oven

Louder noise in siren or electric bell, e.g. burger alarm system.

Lights

Light bulbs

LEDs

Provide lights or indicate something.

E.g. traffic lights, in car dashboards

Heater/Cooler

Provide heat

Cool things down

Keep a room or a greenhouse at correct temperature.

Cooling unit

Keep food fresh