Input Input DevicesDevices

What is input?Input refers to the process of entering data, programs, commands and user responses into memory

Programs are sets of instructions to the computer

Commands are keywords use the tell the computer to do something

User responses are answers that the user inputs into the computer

The keyboard is the most common input device!

102 Keys that represent all of the ASCII characters

Pointing devices

Mouse

Trackball

Touchpad

Pointing Stick

Joystick

Pen input

Touch Screen

Light pen

Digitizer

Graphics tablet

Ball turns wheels causing pointer to move on the screen

The Optical MouseWith advances it mouse technology, it appears that the venerable wheeled mouse is in danger of extinction. The now-preferred device for pointing and clicking is the optical mouse

Optical mice have several benefits over wheeled mice: No moving parts means less wear and a lower chance of failure. There's no way for dirt to get inside the mouse and interfere with the tracking sensors. Increased tracking resolution means smoother response. They don't require a special surface, such as a mouse pad

Trackball

Trackball or mouse...mouse or trackball...why choose?The Orbit® USB Trackball gives you the best features of a mouse and a trackball in one easy-to-use input device, so you don't have to make concessions in your computing. Turn the no-win scenario into a win-win for yourself. Features and Benefits Orbit features the comfort of a mouse and benefits of a trackball Hand-hugging design encourages natural finger motion Trackball offers precise cursor control

Trackball

Touchpad

Pointing Stick

Tablet PC with pointing stick

Used to write or draw on the screen surface.

Written words are converted to word processor text.

Tablet PC’s also have keyboards for input

Palm Pilot

Joysticks

Touch Screen

Used for small amounts of data

Digitizer converts points, lines and curves from a sketch, drawing or photograph.

Graphics Tablet

Used for drawing and Computer Aided Design

CCD

Mirror

How Scanners Work

Mirror focuses light on CCD

CCD converts light to electrical current

ADC converts electrical current into digital values for use in the computer

Digital data may be further converted, using OCR software, into data that a word processor can use ADC

Lens

Flatbed Scanner

OCR Software

Can be used with home computer to turn scanned documents (pictures) into ASCII text that you can use in

a word processor

OCR

Optical Character Recognition

Scanners that can read typewritten, computer-printed and even hand printed characters and convert them to text that can be used in a word processor

• Above is an example of OCR character set

• Note the difference between zero and the letter O

• Frequently used in billing statements

Terminals(Display or video display VDT’s)

Dumb terminals

Keyboard and display screen

Sometimes a modem

Can transmit and receive but not store data

Intelligent terminals

Have built in processors and storage capabilities

Special Purpose Terminals

Point of Sale (POS)

ATM Machines

Can update inventory and do other tasks

Other Input DevicesAlthough text is the most often used form of data input, sound and image input is also used

To use sound you must have a sound card installed in your computer

To use video input you must have a special video card installed in your computer

By using a microphone and a sound card you can store sounds on disk in the form of wave files. (voice or music)

Voice Input

Allows you to use voice to input data into word processors, spreadsheets and databases.

Used by health workers and phone companies

Video Input

ATI video cards allow input from multiple sources

PC Digital Camera

Communicating with pictures through the internet or network at your school

Biological Input

Whiteboard Input

Through the internet both classrooms see the same screen and share input