Chapter #6 Understanding Input

What is Input ?

• Input is any data and instructions entered into the memory of a computer.
• Instructions can be entered into the computer in the form of programs, commands, and user responses.

1. A program is a series of related instructions that tells a computer what tasks to perform and how to perform them.
2. Program respond to commands that a user issues.
3. A user response is an instruction a user issues by replying to a question displayed by a program.

What Are Input Devices ?

• An input device is any hardware component that allows users to enter data and instructions into a computer.

The Keyboard

• A keyboard is an input device that contains keys users press to enter data and instructions into a computer.
• Most desktop computer keyboards have...

1. Between 101 and 105 keys
2. A numeric keypad on the right side of the keyboard
3. Function keys, CTRL keys, ALT keys, and arrow keys
4. WINDOWS key
5. APPLICATION key
6. Toggle keys

• Wired Keyboards : USE port
• Wireless Keyboards : Bluetooth / IrDA
• An ergonomic keyboard has a design that reduces the chance of wrist and hand injuries.
• Ergonomics incorporates comfort, efficiency, and safety into the design of the workplace.
• Keyboards on mobile devices typically are smaller and/or have fewer keys.
• Some phones have predictive text input, which saves time when entering text using the phone's keypad.

Pointing Devices

• A pointing device is an input device that allows a user to control a pointer on the screen.
• A pointer is a small symbol on the screen whose location and shape change as a user moves a pointing device.

Mouse

• A mouse is a pointing device that fits under the palm of your hand comfortably - Most widely used pointing device on desktop computers.
• A mouse can be wired or wireless.

Other Pointing Devices

- Trackball -

• A trackball is a stationary pointing device with a ball on its top or side.

- Touch-pad -

• A touchpad is a small, flat, rectangular pointing device that is sensitive to pressure and motion.

- Pointing Stick -

• A pointing stick is a pressure-sensitive pointing device shaped like a pencil eraser that is positioned between keys on an keyboard.

Touch Screens and Touch-Sensitive Pads

• A touch screen is a touch-sensitive display device.
• Microsoft surface
• Touch-sensitive pads

Pen Input

• With pen input, you touch a stylus or digital pen on a flat surface to write, draw, or make selections.

Game Controllers

• Video games and computer games use a game controller as the input device that directs movements and actions of on-screen objects.

1. Gamepads
2. Joysticks and Wheels
3. Light guns
4. Dance pads
5. Motion-sensing controllers

Digital Cameras

• A digital camera is a mobile device that allows users to take pictures and store them digitally.

1. Studio cameras
2. Field cameras
3. Point-and-shoot camera

• Two factors affect the quality of digital camera photos :

Resolution :

1. Resolution is the number of horizontal and vertical pixels in a display device.
2. A pixel is the smallest element in an electronic display.

Number of bits stored in each pixel :

1. Each pixel consists of one or more bits of data.
2. The more bits used to represent a pixel, the more colors and shades of gray that can be represented.

Voice Input

• Voice input is the process of entering input by speaking into a microphone.
• Voice recognition is the computer's capability of distinguishing spoken words.
• Audio input is the process of entering any sound into the computer.

1. Speech
2. music
3. Sound Effects

• Music production software allows users to record, compose, mix, and edit music and sounds.

Video Input

• Video input is the process of capturing full-motion images and storing them on a computer's storage medium.

1. Record video on a digital video (DV) camera or use a video capture card to convert analog signals to digital.
2. Connect the camera to a port on the system unit.
3. Transfer video and images.

• A Web cam is a type of digital video camera that enables a user to :

1. Capture video and still images
2. Send e-mail messages with video attachments
3. Add live images to instant messages
4. Broadcast live images over the Internet
5. Make video telephone calls

• A video conference is a meeting between two or more grographically separated people.

Scanners and Reading Devices

• Flatbed
• Pen or Handheld
• Sheet-fed
• Drum
• Optical character recognition (OCR) involves reading characters from ordinary documents.
• A turnaround document is a document you return to the company that creates and sends it.
• Optical mark recognition (OMR) reads hand-drawn marks such as small circles or rectangles.
• An OMR device scans the documents and matches the patterns of light.
• A bar code reader, also called a bar code scanner uses laser beams to read bar codes.
• RFID (radio frequency identification) uses radio signals to communicate with a tag laced in or attached to an object.
• An RFID reader reads information on the tag via radio waves.
• RFID can track :

1. Tracking times of runners in a marathon
2. Tracking location of soldiers
3. Employee wardrobes
4. Airline baggage
5. Checking lift tickets of skiers
6. Managing inventory
7. Gauging pressure and temperature of tires
8. Checking out library books
9. Tracking toll payments

• Magnetic stripe card readers read the magnetic stripe on the back of cards such as :

1. Credits cards
2. Entertainment cards
3. Bank cards
4. Other similar cards

• MICR (magnetic ink character recognition) devices read text printed with magnetized ink.
• An MICR reader converts MICR characters into a form the computer can process.
• Banking industry uses MICR for check processing.
• Data collection devices obtain data directly at the location where the transaction or event takes place.
• Used in :

1. Restaurants
2. Grocery stores
3. Factories
4. Warehouses
5. The outdoors

Biometric Inut

• Biometrics a authenticates a person's identity by verifying a personal characteristic :

1. Fingerprint reader
2. Face recognition system
3. Hand geometry system
4. Voice verification system
5. Signature verification system
6. Iris recognition system
7. Retinal scanners

Terminals

• A terminal is a computer that allows users to send data to and/or receive information from a host computer.

1. A POS terminal records purchases, processes payment, and updates inventory.
2. An automated teller machine (ATM) allows users to access their bank accounts.
3. A DVD kiosk is a self-service DVD rental machine.

Input Devices for Physically Challenged Users

• Several input devices are available to assist physically challenger users:

1. Keygaurd
2. Keyboards with larger keys
3. On-screen keyboard
4. Various pointing devices
5. Head-mouted pointer
6. Gesture recognition
7. Computerized implant devices
8. Keyboard with larger keys
9. Head-mounted pointer
10.