1 Input & Output Input and Output: What is the difference between the two? (pg. 253) Classify...

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Input & Output Input and Output: What is the difference between the two? (pg.

253) Classify devices into input or output hardware

Terminals: What is the difference between dumb terminals, intelligent terminals and internet terminals? (pg. 256)

RFID: What are some applications of RFID technology? What are the security and privacy concerns of this technology? (pg. 276)

Biometrics: What is it and what are some applications of the technology?

Speech recognition: What is it and how does it work? Screen clarity (dot pitch, resolution (dpi), color depth, and

refresh rate): Is it better for each to be lower or higher? What does each measure?

Softcopy vs Hardcopy Ergonomics: What is it and why is it important? What are some

medical conditions that can result from computer usage? (pg 289-291)

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Input & Output

Input Hardware Devices that translate data into a form

the computer can process Translates words, numbers, sounds, and

pictures into binary Output Hardware

Devices that translate information processed by the computer into a form humans can understand

Translates binary into words, numbers, sounds, and pictures

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Input Hardware Pointing Devices

Mouse is the principal pointing tool Ball inside the mouse touches the

desktop and rolls around Two internal rollers touch the ball One roller picks up motion in x (up),

the other in y (down) The rollers turn a shaft that spins a

disk that breaks an LED signal into light pulses that are seen by an infrared sensor

Processor chip in mouse reads the pulses and turns it into binary

What is the difference between “cursor” and “curser”?

Control the position of the cursor or pointer in the screen and allow the user to select options displayed on the screen

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Pointing Stick Looks like a pencil eraser in the lower

center of a laptop keyboard

Trackball A movable ball mounted on top of a stationary

device Good for locations where a mouse couldn’t

move enough Requires more frequent cleaning to remove

finger oils

Touchpad To use: slide your finger over this small flat

surface Click by tapping you finger on the surface May require more practice to use than a

mouse

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Touch Screens A video display screen sensitized to

receive input from a finger Cruder than a mouse, because fingers

are big Problems: touch screens that show a

display that is not precisely aligned with the input

Pen input Use a pen-like stylus for input rather than typing

on a keyboard Use handwriting recognition to translate cursive

writing into data

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Light Pen A light-sensitive pen-like device that uses a

wired connection to a computer terminal Bring the pen to the desired point on the

display screen and press a button to identify the screen location

Used in situations that require gloves Less crude than a touch screen

Digitizer Uses an electronic pen or puck to convert

drawings and photos to digital data Digitizing tablets are used in architecture

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Input HardwareScanning & Reading Devices

Source Data Entry devices create machine-readable data and feed it directly into the computer

Scanners Use light-sensing equipment to translate

images of text, drawings, and photos into digital form

Image scanners are used in electronic imaging Resolution refers to the image sharpness,

measured in dots per inch (dpi) Flatbed scanners work like photocopiers – the

image is placed on the glass surface, then scanned

Other types are sheet-fed, hand-held, drum, and pen scanners

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Input HardwareBar-Code Readers

Photoelectric (optical) scanners that translate bar code symbols into digital code

The digital code is then sent to a computer The computer looks up the item and

displays its name and pricing info

Bar code types 1D holds up to 16 ASCII characters 2D can hold 1,000 to 2,000 ASCII

characters 3D is “bumpy” code that differentiates by

symbol height Can be used on metal, hard rubber, other tough

surfaces

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Input HardwareFax Machines

Facsimile Transmission Machines – scan an image and send it as electronic signals over telephone lines to a receiving fax, which prints out the image on paper Dedicated fax machine Fax modem

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Input HardwareAudio Input Devices

Records analog sound and translates it into digital files for storage and processing

Two ways to digitize audio Sound Board (card)

An add-on board in a PC that converts analog sound to digital sound, stores it, and plays it back to speakers or amp

MIDI Board Stands for Musical Instrument Digital

Exchange Uses a standard for the interchange

between musical instruments, synthesizers, and PCs

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Input HardwareWebcams and Video-input Cards Webcams

Video cameras attached to a computer to record live moving images then post them to a website in real time

Require special software, usually included with the camera

Frame-grabber video card Can capture and digitize 1 frame at

a time Full-motion video card

Can convert analog to digital signals at rates up to 30 frames per second

Looks like a motion picture

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Input HardwareDigital Cameras

Use a light-sensitive processor chip to capture photographic images in digital form and store them on a small disk in the camera or on flash memory cards Most can be connected to a PC by

USB or FireWire Can allow you to take more

pictures and decide which ones to print and save

But pictures are subject to loss by diskette or flash memory failure or computer virus if you store them on the PC

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Input HardwareCamera Phones

Digital cameras are now on cellphones Convenience of being able to take photos, then

instantly email or message them to someone else Can provide instant record of traffic accidents, etc

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Speech recognition: What is it and how does it work? Screen clarity (dot pitch, resolution (dpi), color depth, and refresh

rate): Is it better for each to be lower or higher? What does each measure?



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Input Hardware Terminal Types

Dumb Terminals a.k.a. Video Display Terminal (VDT) Has display screen and keyboard Can do input and output only – no data processing

Intelligent Terminals Has screen, keyboard, and memory Can perform some local functions

Internet Terminals Powers directly up into a browser

Web terminal displays web pages on a TV set Network computer is a stripped-down PC to connect

people to networks Online game player connects to internet for online

gaming PC/TV merges a full-blown PC with a TV

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Input HardwareRFID Tags

Radio-frequency ID tags are based on an identifying tag with a microchip containing specific code numbers Scanners use radio waves to read

them and match the codes to a database

Enables items to be tracked without physical contact Drivers put RFID tags in cars to

automatically pay tolls FDA is tagging certain drugs with RFID to

avoid counterfeits Carmakers are using it for car electronic

keyless entry RFID tags are implanted under skin of

pets to aid in recovery and identification when they get lost

How about humans?

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Input HardwareBiometrics

The science of measuring individual body characteristics, then using them to identify a person through a fingerprint, hand, eye, or facial characteristic Becoming a big business as more

companies become concerned about security

Makes identity theft much more difficult when records are identified by biometrics as well as passwords

For more information see http://www.l1id.com/ http://www.precisebiometrics.com/

Remember “Minority Report”?

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Input HardwareSpeech-Recognition Systems

Uses a microphone or telephone as an input device. Converts a person’s speech into digital signals by comparing against 200,000 or so stored patterns. Used in places where people need their

hands free – warehouses, car radios, stock exchange trades

Helpful for people with visual or physical disabilities that prevent them from using other input devices

Still not easy enough to use to substitute for the mouse/keyboard for fast document processing ScanSoft’s Open Speech Dialog Apple Speech Recognition ScanSoft’s Navigon MobileNavigator 5

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Output HardwareDisplay Screens Making a good choice when choosing a display

Dot pitch (dp) is the amount of space between adjacent pixels (picture elements) on screen The closer the pixels, the crisper the image Get .25 dp or better

Resolution refers to the image sharpness The more pixels the better the resolution Expressed in dots per inch (dpi)

Color depth or bit depth is the number of bits stored in a dot The higher the number the more true the colors 24-bit color depth is better than 8-bit color depth

Refresh rate is the number of times per second the pixels are recharged – a higher rate gives less flicker

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Output HardwareMonitors

Cathode Ray Tube (CRT) is a vacuum tube used in a computer or terminal display screen Watch the PC ads to make sure your monitor

is included Flat panel displays are made of 2 plates of

glass separated by a layer of liquid crystals that line up to transmit or block light Preferable to CRTs because they take up less

room on the desktop Latency problems make them less desirable

for online games players

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Output HardwareMonitors

Video Standard SVGA XGA SXGA UXGA QXGA

Principal resolution (pixels) 800 x 600 1024 x 768 1280 x 1024 1600 x 1200 2048 x 1536

Internals of a CRT screenCarbon nanotube

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Output Hardware

Softcopy Data that is shown on a display screen or

is in audio or voice form; exists electronically

Output that is ephemeral in nature Hardcopy

Printed and film output Output that is more permanent in nature

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Output HardwarePrinters

Impact Printers

Laser Printers

Inkjet Printers

Thermal Printers

Form characters or images by striking a print hammer or wheel against an ink ribbon Dot matrix printers

Use drums and toner like in photocopiers Page Description Language (PDL) PostScript and PCL are PDL types Produce crisp, professional pages

Spray ink from 4 nozzles at high speed Quiet, inexpensive color printers Often less precise than laser printers

Low to medium resolution printers that use thermal paper that darkens in time

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Output HardwarePlotters

A specialized output device designed to produce large high-quality graphics in a variety of colors The earliest output device that could

produce graphics Pen plotters use one or more colored pens Electrostatic plotters lie partially flat on a

table and use toner like photocopiers Large-format plotters are large-scale

inkjet printers used by graphic artists

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I/O Quality of Life: Health & Ergonomics Ergonomics is the methodology of designing

a workplace to make working conditions and equipment safer and more efficient Keyboards must be placed at the correct

height depending on each worker’s size Monitor refresh rates must be fast enough to

avoid eyestrain Monitor heights must be correct for

comfortable viewing Sound-muffling should be used for loud

printers to reduce workplace noise Wrist rests may help avoid

carpal tunnel syndrome

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Future of Input and Output

This is a fruitful area for research, including Intelligent sensors More data input from remote locations More source data automation Input help for the disabled More sophisticated touch devices Better speech recognition Improved digital cameras Gesture recognition

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Future of Input and Output

This is a fruitful area for research, including Pattern-recognition and biometric devices Brainwave devices Better and cheaper display screens Improved video on PCs 3-Dimensional output Miniaturization for improved data transfer

speeds to I/O devices

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