Legacy Plug and Play

Plug and Play (English " plug and play " for or " plug and play "), even Plug ' n Play or Plug & Play ( short PnP) called, is a term from the field of computer technology that allows you the ability of a computer describes new devices - usually peripherals - to be able to connect to must make settings without then install device drivers or.

More details

There are several different names and variations of the term that describe similar characteristics, such as hot-plug. The term Plug and Play is usually associated with the Microsoft company in connection that used this designation for its first product Windows 95. Since the process at the beginning was technically immature, holds to this day the mocking name " Plug and Pray" ( " plug and pray ").

Plug and Play works only if it is supported by both hardware and software. The hardware normally creates an identification code so that the software can detect the device correctly. The now detached by USB Apple Desktop Bus (ADB ) used for this purpose a code of four bits, most systems are now using longer codes of various kinds in order to transmit more information, such as device names or serial numbers can.

On the hardware side is necessary for the computer bus must detect changes in the configuration, when devices are added or removed. With the introduction of modern systems - particularly USB and FireWire - has just been introduced into the computer bus that ability.

Finally, the operating system must be able to deal with the changes when connecting or disconnecting devices. This means that there is an interrupt ( see Interrupt Request ) of the system bus triggers indicating the changes, and then determine what has been changed. In older bus designs all system information had to be read to find out what has changed. When using multiple devices, this can take a relatively long time to complete. Modern systems are therefore designed so that the search for changes in as little time as needed. In the case of USB ( and other applications ), a hub system is used for this.

If a configuration change is detected, the operating system reads the information provided by the new device available to identify it. Next, it must be in operation load the necessary drivers for the device, if that is not already done.