Input/Output devices

Input/Output devices

1. Manual Input

   • Keyboard
   • Mouse
   • Microphone
   • Scanner
   • Joystick

2. Automatic Input

   • Sensors: Used in a feedback cycle, linked to a control program that specifies suitable levels
   • Barcode reader: Information from a database is recalled which identifies the product scanned. This also assists stock management.
   • Magnetic strip reader: The magnetic strip on the back of the card can hold the personal details of the card owner and, with the necessary PIN, will allow access to secure information, eg bank account details. Data stored on the strip is scanned and input into a computer system by a magnetic stripe reader.

3. Central processing unit (CPU) (processor))The CPU is responsible for executing a sequence of stored instructions called a program. This program will take inputs from an input device, process the input in some way and output the results to an output device.

4. Output

   • Monitor (CRT or LCD)
   • Printers
     • Laser printers are quite expensive to buy and run but produce a high quality output and are quiet and fast.
     • Ink-jet printers offer black and white or colour printing with reduced levels of quality and speed. Colour ink jet printers are cheaper to buy than colour laser printers.
     • Dot matrix printers are not so common today. They are comparatively noisy and low quality but are cheap to run and are used when carbon copies or duplicates need to be made, such as for wage slips. Also, they are useful in dirty environments such as a garage because they are much sturdier than the other two types of printer.
   • Plotter: A plotter can be used to produce high quality, accurate, A3 size or bigger drawings. They are usually used for Computer Aided Design (CAD) and Computer Aided Manufacture (CAM) applications, such as printing out plans for houses or car parts.
   • Speakers
   • Projectors
   • Motors
   • Buzzers