Input and Output Devices 12.1 Input Devices Keyboards, MIDI keyboard, ergonomics keyboard Pointing devices: used for GUI, example: mouse(mice), Trackballs, touch pads, track Points, Joysticks, Touch screens, Digitizing tablets, handwriting boards Image scanner: used with optical character recognition (OCR) software to convert image to text.
Optical reader: Bar code readers: fast and more accurate than keyboard input. Optical Mark readers: MC answer sheets, questionnaire, forms Microphone Used with speech recognition software Digital cameras and Digital video cameras, Web cam Major spec: DC
12.2 Output devices Visual Display Unit: Cathode Ray Tube, Liquid Crystal display, LED display (Some are Lighting only) Comparing the Physical size and Energy consumption of LCD, LED and CRT display. Some major specification of LCD, LED.
Speakers/ Headphone (stereo, mono) Printers
Page printer: e.g. laser printer: Memory size (Cache size) is important. Speed: ppm (Page per print) resolution: e.g. 600 dpi Plotters 3D printers Multi-function printers: Scanning, copying, fax etc. Video projectors 12.3 Daily applications of input and output devices (Exam coverage will not be confined to the example below) Identify the input and output devices of a POS terminal, cheque deposit machine, cash deposit machine, iCenter at MTR (P.58), Kiosk at Shopping Mall etc. SOHO (Small office and Home office) Telecommuting: Work outside office using IT. Multi-function printer: Scanner, printer, fax, photocopier. Conference Room |