input devices. what is input? input refers to the process of entering data, programs, commands and...
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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
Pointing devices
Mouse
Trackball
Touchpad
Pointing Stick
Joystick
Pen input
Touch Screen
Light pen
Digitizer
Graphics tablet
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
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
Joysticks
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