Summary Grade 11 CAT Theory Notes: Inputs and Outputs

Input and Output
Input
 Running software with instruction
 Data that must be processed
 Image capture
 Digital cameras:
 Smartphones, compact cameras, top-end DSL
 Images already in digital form
 Quality depends on sensor size, zoom type, resolution(MP), ISO rating
 Scanners:
 Input device that converts images into digital format
 Quality determined by resolution (dpi) and colour depth
 Higher dpi + colour depth give higher quality but bigger file sizes
 OCR software converts scanned images to editable text
 Quality of scanned image depends on quality of original
 Biometric Input:
 Capturing unique biological features of a person
 Used for security reasons
 More secure that passwords
 Additional hardware + software may be needed
 Input at ATMs:
 Dedicated device, gets input from user + other sensors
 Interact via touch screen/keypad/buttons
 Thieves use card skimmers + cameras to steal date from cards
 Input into POS Systems:
 Uses barcodes + RFID tags to record stock items in database
 Faster processing, better accuracy + better stock control
 Touch Screens:
 More natural way to interact with computing devices
 Pen tablets use stylus for higher precision
 Intuitive to use, allows drawing + gestures, no keyboard needed
 Typing is not as fast + screen can get dirty
 Better for handheld devices
 Data Collection:
 Capture data using variety of inputs (sensors, cameras, radio signal)
 Especially useful I situations where difficult/dangerous for humans
 More accurate + faster than human input
 Difficult to repair – inaccessible location
 Input into smartphones and consumer tablets:
 Multiple types of user-controlled input
 Touch screen
 Hardware buttons
 Voice recognition apps useful for disabled users
 Other input types operate on system level
 GPS
 WiFi
 Alternative keyboards
 Mobile devices create virtual keyboards – image on screen
 Virtual keyboards projected onto surface using laser/led light