Chapter 5 - Input

What Is Input?

What is input?

° Any data or instructions you enter into the memory of the computer

° Users can input data and instructions in a variety of ways

What are two types of input?

° Data

• A collection of raw unprocessed facts, figures, and symbols

° Instructions

• Programs

• Commands

• User responses

What is information?

What are the three forms of instructions?

What are two features of most programs today?

° Menu-driven program

• Provides menus as a means of entering commands

• Menus contain a list of options from which you select

What are Input Devices?

What is an input device?

° Any hardware component that allows you to enter data, programs, commands, and user responses into a computer

The Keyboard

What is a keyboard?

° An input device that contains keys you press to enter data into the computer

° Typing area

• Letters of the alphabet, numbers, punctuation marks, and other basic keys

What are the features of a typical keyboard?

What are some special types of keys?

° SHIFT, CTRL, ALT and others

• Used in combination with other keys to issue commands

What are alternative forms for commands?

° Many programs allow you to use a button, a menu, or a function key to obtain the same result

What are the different types of keyboards?

° QWERTY keyboard

• Standard computer keyboard named for the layout of its typing area

° Enhanced keyboard

• 12 function keys along the top, 2 CTRL keys, 2 ALT keys, and a set of arrow and additional keys between the typing area and the numeric keypad

° Cordless keyboard

• Battery-powered device that transmits data using wireless technology

° Notebook and many handheld keyboards

• Built into the top of the system unit

What is a portable keyboard?

° A full-sized keyboard you conveniently can attach and remove from a handheld computer

What is an ergonomic keyboard?

° Designed to minimize strain on your hands and wrists

Pointing Devices

What is a pointing device?

° An input device that allows you to control a pointer on the screen

° A pointer is a small symbol on the screen

° The pointer takes several shapes

Technology Trailblazer

Douglas Engelbart

° Scientist at the Stanford Research Institute in the 1960s

° Part of a team that designed the first mouse with funding from NASA and the U.S. Department of Defense

° Filed a patent for his design in 1965, but his thinking was too ahead of his time to reach fruition

Mouse

What is a mouse?

° A pointing device that fits comfortably under the palm of your hand

° The most widely used pointing device on desktop computers

° The mouse controls the movement of the pointer, also called the mouse pointer, on the screen

How does a mechanical mouse work?

° A rubber or metal ball is on its underside

° When the ball rolls in a certain direction, electronic circuits in the mouse translate the movement of the mouse into signals the computer understands

How does an optical mouse work?

° Uses devices that emit and sense light to detect the mouse’s movement

° Some use optical sensors; others use laser

° More precise than a mechanical mouse and does not require cleaning

° Slightly more expensive

How can a mouse connect to your computer?

How do you use a mouse?

° As you move the mouse, the pointer on the screen also moves

Other Pointing Devices

What are some common mouse operations?

° Point

° Click

° Right-click

° Double-click

° Drag

° Right-drag

° Rotate wheel

° Press wheel button

Company on the Cutting Edge

Logitech

° World’s largest manufacturer of the mouse

° Has created more than 200-million corded and cordless devices since 1981

° Also designs, produces, and markets keyboards, optical trackballs, joysticks, gamepads, and Internet video cameras

Other Pointing Devices

What is a trackball?

° A stationary pointing device with a ball on its top

° To move the pointer, you rotate the ball with your thumb, fingers, or the palm of your hand

What is a touchpad?

° Also called a trackpad

What is a pointing stick?

° A pressure-sensitive pointing device shaped like a pencil eraser that is positioned between keys on the keyboard

What are a joystick and a wheel?

° Help the user control the actions of players and vehicles in game and simulation software

° A joystick is a vertical lever mounted on a base

• You move the lever in
different directions to
control the actions of a
vehicle or player

What is a light pen?

° A handheld input device that contains a light source or can detect light

What is a touch screen?

° A touch-sensitive display

What is a stylus?

° Used in professional graphical applications

° A graphics tablet, also called a digitizer or digitizing tablet, is a flat rectangular, electronic plastic board used with a stylus

What is a cursor?

° A cursor is a device that looks similar to a mouse, except it has a window with cross hairs

What is an electronic signature?

° Also called an e-signature

What is handwriting recognition software?

° Some notebooks and many handheld computers have touch screens that allow you to input data using a stylus

Voice Input

What is voice input?

° The process of entering data by speaking into a microphone that is attached to the sound card on the computer

° Voice recognition, also called speech recognition, is the computer’s capability of distinguishing spoken words

How does voice recognition work?

What is audio input?

° The process of entering any sound into the computer such as speech, music, and sound effects

° Requires a sound card

° Input sound via a device such as a microphone, tape player, CD player, or radio

° Windows stores audio files as waveforms

• Called WAV files with a .wav extension

What is MIDI?

° An external device such as an electronic piano keyboard used to input music and other sound effects

° Music is stored in the computer

Input Devices for Handheld Computers

What is the primary input method for a handheld computer?

° A handheld computer typically includes a basic stylus

How is a data entered into a handheld device?

Company on the Cutting Edge

Palm

° More than two million people worldwide
have a Palm
handheld computer

° Commands three-fourths of the
handheld computer market

° More than 43,000 developers are working on new software applications and hardware add-ons

Technology Trailblazer

Donna Dubinsky

° President and CEO of 3Com’s Palm Computing Division

° Founded Handspring with Jeff Hawkins in 1998 with the goal of becoming the leading handheld computing device maker for the consumer market

° The most-rapidly adopted new computing product ever manufactured

Digital Cameras

What is a digital camera?

° Allows you to take pictures and store the photographed images digitally

° Images are viewable immediately on the camera

How are digital camera images stored?

° Generally, the more expensive cameras use higher-capacity storage devices, which means they can hold more pictures

How does a digital camera work?

What are three basic types of digital cameras?

What is resolution?

° The sharpness and clearness of an image

° The higher the resolution, the better the image quality, but the more expensive the camera

° A pixel (picture element) is a single point in an electronic image

What are measurements of resolution?

Video Input

What is video input?

° The process of entering a full-motion recording into a computer and storing it on a storage medium

° Also called video capture

What are some factors related to video input?

° Video files can require huge amounts of storage space

° Video compression is used to decrease the size of the files

° Files can be compressed using software or hardware

What is a PC video camera?

° A DV camera that allows the home user to record, edit, and capture video and still images and to make video telephone calls on the Internet

° Also called a PC camera

How can you use a PC video camera?

° Video telephone call

• Both parties see each other as they talk

° To provide security in your home

• The PC camera can be set to take digital photographs at preset time intervals

° A digital watermark

• A small digital image that when held in front of a PC camera, displays an associated Web page on the computer screen

What is a Web cam?

° A video camera whose output displays on a Web page

° Also called a cam

What is videoconferencing?

° A meeting between two or more geographically separated people who use a network on the Internet to transmit audio and video data

Scanners and Reading Devices

What is a scanner?

° A device that captures data directly from source documents

° A source document is the original form of the data

What is an optical scanner?

° Usually called a scanner

° A light-sensing input device that reads printed text and graphics and then translates the results into a form the computer can use

How does a flatbed scanner work?

What are various types of scanners?

What is image processing?

° Also called imaging

° Consists of capturing, storing, analyzing, displaying, printing, and manipulating images

° Allows you to convert paper documents into an electronic form

What is an optical reader?

° A device that uses a light source to read characters, marks, and codes and then converts them into digital data that a computer can process

What is optical character recognition (OCR)?

° A technology that involves reading typewritten, computer-printed, or handwritten characters from ordinary documents and translating the images into a form that the computer can understand

What is an OCR font?

° An OCR font, such as OCR-A, is used with OCR devices

° An OCR device determines the shapes of characters by detecting patterns of light and dark

° OCR software converts the shapes into characters the computer can understand

What is a turnaround document?

° Many companies use OCR characters on turnaround documents

° A turnaround document is one that you return to the company that creates and sends it

What is optical mark recognition (OMR)?

° Reads hand-drawn marks such as small circles or rectangles

° A person places these marks on a form, such as a test, survey, or questionnaire answer sheet

What is a bar code scanner?

° Uses laser beams to read bar codes

What is a bar code?

° An identification code that consists of a set of vertical lines and spaces of different widths

° Represents data that identifies the manufacturer and the item

° The scanner reads a bar code by using light patterns that pass through the bar code lines

What are some widely used types of bar codes?

What is a magnetic ink character recognition reader (MICR)?

° Can read text printed with magnetized ink

° The banking industry almost exclusively uses MICR for check processing

What is wireless input?

° A handheld computer or device is used to collect data wirelessly at the location where the transaction or event takes place

° Later the data is transferred to a desktop computer through a docking station

Input Devices for Physically Challenged Users

Why are computers important for those with physical limitations?

° Americans with Disabilities Act (ADA) requires any company with 15 or more employees make reasonable attempts to accommodate the needs of physically challenged workers

° Many input devices address the needs of users with physical limitations

What is a keyguard?

° A metal or plastic plate placed over the keyboard

What is an on-screen keyboard?

° A graphic of a standard keyboard that displays on the user’s screen

° A pointing device is used to press the keys

What options are available for users with motor disabilities?

° A handheld switch can be used as a pointing device

° A portable computer or pointing device can be mounted to a wheelchair

° People with limited hand movement can use a head-mounted pointer

What are new developments in computing that will benefit physically challenged users?

° Developments now in the prototype stage attempt to provide users with a natural computer interface

PUTTING IT ALL TOGETHER

What type of input devices do users require?

Summary of Input

° What is input?

° What are input devices?

° The keyboard

° Pointing devices

° Mouse

° Other pointing devices

° Voice input

° Input devices for handheld computers

° Digital cameras

° Video input

° Scanners and reading devices

° Input devices for physically challenged users

Chapter 5 Complete