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Peripheral Devices: Input or output devices that are connected to computer are called peripheral devices. These devices are designed to read information into or out of the memory unit upon command from the CPU and are considered to be the part of computer system. These devices are also called peripherals. For example: Keyboards, display units and printers are common peripheral devices. There are three types of peripherals: > Input peripherals: Allows user input, from the outside world to the computer. Example: Keyboard, Mouse etc. Output peripherals: Allows information output, from the computer to the outside world. Example: Printer, Monitor etc. Input-Output peripherals: Allows both input (from outside world to computer) as well as, output (from computer to the outside world). Example: Touch screen etc. . v Vv Interfaces: Interface is a shared boundary between two separate components of the computer system which can be used to attach two or more components to the system for communication purposes. There are two types of interface: > CPU Interface > I/O Interface Input-Output Interface: Peripherals connected to a computer need special communication links for interfacing with CPU. In computer system, there are special hardware components between the CPU and peripherals to control or manage the input-output transfers. These components are called input- output interface units because they provide communication links between processor bus and peripherals. They provide a method for transferring information between internal system and input-output devices. Data [ Processor |— Address ad Control} Interface Keyboard Magnetic & Display Tape Terminals pg. 56 { : . ! ‘ i | i ! ) ’ ) ) } Scanned with CamScanner 
