Input and Output: Data In, Information Out Lesson 4 What You Will Learn The various types of input and output and their purposes The differences between.

Input and Output: Data In, Information OutLesson 4

What You Will Learn

The various types of input and output and their purposes

The differences between a computer keyboard and a typewriter keyboard

The special keys and their purpose

The pros and cons of speech recognition as an alternative to keyboard use

The various types of printers, monitors, mouse and pointing devices

Devices used to get sound, video and images into the computer

What are the types of input?

Software- Programs transferred from storage devices to the computer’s memory

Data- Unorganized information (words, numbers, images or sounds) that the computer converts to meaningful information

Commands- Instructions that tell the computer what to do

Responses- Prompts requiring user feedback

What are input devices?

Hardware that enable you to get programs, data, commands and responses into the computer’s memory

Digital Cameras

Microphone

What is the purpose of a keyboard?

Allows the computer user to enter words, numbers, punctuation, symbols, and special function commands into the computer’s memory

What are the types of keyboards?

Enhanced or Extended keyboard- Typically 101 keys laid out in the QWERTY fashion; Connected to the computer by a serial cable

Cordless keyboard- Uses infrared or radio wave signals

Ergonomic keyboard- Designed to help prevent cumulative trauma disorder (CTD) or damage to nerve tissues in the wrist and hand due to repeated motion

Enhanced / Extended Keyboard Ergonomic Keyboard

What is speech recognition?

A type of input, in which, the computer recognizes words spoken into a microphone

Special software and a microphone are required

Latest technology uses continuous speech recognition where the user does not have to pause between words

What are pointing devices?

Enable the user to control the movements of an on-screen pointer

Enable the user to initiate commands and responses to the active program

Are used to provide input in graphics programs

Pointing Devices

What are the types of pointing devices?

Mouse

Joystick

Touch pad

Touch screen

Trackball

Pointing stick

Pen

What are the types of mice?

PS/2- Most commonly used; Connects to PS/2 port or USB port

Serial- Not commonly used; Connects to a serial port

Cordless- Uses infrared signals; Must be within sight of receiving port

PS/2 Mouse Cordless Mouse

How does a mouse work?

Mouse buttons- Enable the user to initiate actions

Clicking (left, right or double click)- Allows the user to select an item on the screen, open a program or dialog box

Click and drag- Holding down the left mouse button and moving the mouse enables the user to move objects on the screen

Mechanical mouse- Uses rotating ball to position the pointer on the screen

Optical mouse- Uses laser light to determine the pointer position

What are other pointing devices?

Trackball

Pointing stick

Touchpad

Joystick

Touch Screen

Pen

What are other pointing devices?

Biometric Fingerprint Reader

USB Tablet

Optical input devices

Digital Cameras Digital Video

Videoconferencing Web cams

Click on picture to play video

Other input devices

Scanners

Flatbed Handheld

Fax Machines

Other input devices

Image processing systems- Used in business , industry and science to input data without manually keying it in

Magnetic-ink character recognition- Used by banks to process checks

Bar code reader

Biological feedback devices- Use body movements as input

Chemical detectors- Molecules of chemicals are used as input

What are output devices?

Peripheral devices that enable us to view or hear the computer processed data

Visual output- Text, graphics and video

Audible output- Sounds, music and synthesized speech

What is a visual display system?

Composed of two parts

Video adapter- Responsible for video quality

Monitor- Displays video adapter’s output

What is a video adapter?

Also called display adapter, video card, or graphics card

Plugs into expansion slot on motherboard

Contains memory called video RAM (VRAM)

Designed to work with digital or analog monitors

Converts digital signals to analog

Determines a monitor’s maximum resolution (VGA/Super VGA)

Determines a monitor’s refresh rate

3D graphics adapter- Enables 3 dimensional images

Multi-display video adapter- Permits a connection of two monitors at a time

What is a monitor?

A peripheral device which displays computer output on a screen

Screen output is referred to as a soft copy

What are the types of monitors?

Cathode-ray tube (CRT)- Resemble televisions; Use picture tube technology; Inexpensive, take up desk space and use a lot of energy

Liquid Crystal Display (LCD or flat-panel)- Cells sandwiched between two transparent layers form images; Used for notebook computers, PDA’s, cellular phones and personal computers; Expensive, take up less desk space and use less energy

CRT LCD

What’s the difference between a monochrome and color monitor?

Monochrome

Only two colors; Either green or amber on black background

Grayscale colors are black and white and shades of gray

Color

Capable of displaying 16.7 million colors

What are monitor specifications? Screen size- The diagonal measurement of the screen surface in inches (15, 17, 19, 21)

Resolution- The sharpness of the images on the screen determined by the number of horizontal and vertical pixels that the screen can display (800x600, 1024x768, 1600x1200)

Dot pitch- The distance between each pixel on the screen measured in millimeters (.22mm, .25mm, .28mm)

Refresh rate- The speed in which the screen is redrawn (refreshed) measured in Hertz (Hz) (60Hz, 75Hz)

What is a printer?

A peripheral device that produces a physical copy (hard copy) of the computer’s output

Two basic types:

Impact printer

Nonimpact printer

What is an impact printer?

A printer that has a print head that contacts the paper to produce a character

Uses ink ribbon

Noisy; Near-letter quality printouts; Not commonly used today

Dot-matrix- Pins used to make characters

Impact printer Dot-matrix

What is a nonimpact printer? Quiet; Most commonly used

Inkjet printer- Also called bubble-jet; Makes characters by inserting dots of ink onto paper; Letter-quality printouts; Cost of printer is inexpensive but ink is costly

Laser printer- Works like a copier; Quality determined by dots per inch (dpi) produced. Color printers available; Expensive initial costs but cheaper to operate per page

Inkjet

Laser

What is a multifunction printer?

A combination of nonimpact printer, scanner, fax machine, and copier in one unit

What is a plotter?

A printer that uses a pen that moves over a large revolving sheet of paper

Used in engineering, drafting, map making and seismotology

What is audio output?

The ability of the computer to output sound

Two components needed:

Sound card- Plays contents of digitized recordings

Speakers- Attach to sound card

Plays various formats i.e. WAV, MPEG, MP3 and MIDI

WMA MIDI MP3 WAV

Beethoven 1:15 min

Rocky 2:56 min

Hornsby 48 sec

Cheers 15 sec

Click on icon to play music

Click on icon again to stop playing

Try clicking on Cheers while playing music

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