Editing Plug and play (section)

{{Short description|Automatically discovering of components without manual configuration}}
{{Distinguish|Universal Plug and Play}}
{{About||the legacy extension specifications developed by Intel and Microsoft|Legacy Plug and Play|plug and play game or system|Handheld TV game|the startup accelerator|Plug and Play Tech Center}}
In [[computing]], a '''plug and play''' ('''PnP''') device or [[Bus (computing)|computer bus]] is one with a specification that facilitates the recognition of a hardware component in a system without the need for physical device configuration or user intervention in resolving resource conflicts.<ref name="pcguidedefinition">{{Cite web|url=https://www.pcguide.com/ref/mbsys/res/pnp-c.html|title=Plug and Play|last=Kozierok|first=Charles M.|date=April 17, 2001|website=The PC Guide|access-date=2018-10-16}}</ref><ref name="pcmagdefinition">{{Cite web|url=https://www.pcmag.com/encyclopedia_term/0,2542,t=plug+and+play&i=49389,00.asp|title=plug and play Definition from PC Magazine Encyclopedia|website=pcmag.com|language=en|access-date=2018-10-16|archive-date=2013-03-27|archive-url=https://web.archive.org/web/20130327175300/http://www.pcmag.com/encyclopedia_term/0%2C2542%2Ct%3Dplug+and+play%26i%3D49389%2C00.asp|url-status=dead}}</ref> The term "plug and play" has since been expanded to a wide variety of applications to which the same lack of user setup applies.<ref>{{cite web|url=https://answers.microsoft.com/en-us/windows/forum/windows_other-hardware/how-or-where-do-i-find-microsoft-wpd-enhanced/a54fc9fe-bea1-4f84-a027-375d39602a55|title=How or where do I find Microsoft WPD Enhanced Storage Certificate|date=December 28, 2011|website=microsoft.com|access-date=2018-10-16}}</ref><ref>{{cite web
 |title        = What does Plug aNd Play mean?
 |url          = https://www.definitions.net/definition/Plug%20aNd%20Play
 |access-date  = 2018-12-08
 |archive-url  = https://web.archive.org/web/20181016170809/https://www.definitions.net/definition/Plug%20aNd%20Play
 |archive-date = 2018-10-16
 |url-status     = dead
}}</ref>

Expansion devices are controlled and exchange data with the host system through defined memory or [[Input/output|I/O]] space port addresses, [[direct memory access]] channels, [[interrupt request]] lines and other mechanisms, which must be uniquely associated with a particular device to operate. Some computers provided unique combinations of these resources to each slot of a [[motherboard]] or [[backplane]]. Other designs provided all resources to all slots, and each peripheral device had its own address decoding for the registers or memory blocks it needed to communicate with the host system. Since fixed assignments made expansion of a system difficult, devices used several manual methods for assigning addresses and other resources, such as hard-wired jumpers, pins that could be connected with wire or removable straps, or switches that could be set for particular addresses.<ref>{{cite web
|title=Legacy Plug and Play Guidelines - Microsoft Download Center
|url=http://download.microsoft.com/download/5/7/7/577a5684-8a83-43ae-9272-ff260a9c20e2/pnp_legacy.doc
|access-date=2018-10-16
|archive-url=https://web.archive.org/web/20161216133035/http://download.microsoft.com/download/5/7/7/577a5684-8a83-43ae-9272-ff260a9c20e2/pnp_legacy.doc
|archive-date=2016-12-16
|url-status=dead
}}</ref> As microprocessors made mass-market computers affordable, software configuration of I/O devices was advantageous to allow installation by non-specialist users. Early systems for software configuration of devices included the [[MSX]] standard, [[NuBus]], [[Amiga]] [[Autoconfig]], and IBM Microchannel.  Initially all [[expansion card]]s for the [[IBM PC compatible|IBM PC]] required physical selection of I/O configuration on the board with jumper straps or [[DIP switch]]es, but increasingly [[Industry Standard Architecture|ISA bus]] devices were arranged for software configuration.<ref name=BYTE>{{cite magazine |magazine=BYTE |date=October 1991
|title=Does it pay to Plug and Play (COVER STORY}}</ref> By 1995, [[Microsoft Windows]] included a comprehensive method of enumerating hardware at boot time and allocating [[system resource|resource]]s, which was called the "Plug and Play" standard.<ref>{{cite magazine  |magazine=DrDobbs.com
|title=Plug and Play Run-Time Services  |date=September 1, 1995
|url=http://www.drdobbs.com/windows/plug-and-play-run-time-services/184409623
|quote=Run-time services (detectable only in software) are central to Windows ... that finds the Plug and Play header, then calls run-time services. ... Windows 95 includes an "Add New Hardware" wizard}}</ref>

Plug and play devices can have resources allocated at boot-time only, or may be [[Hot swapping|hotplug]] systems such as [[USB]] and [[IEEE 1394]] (FireWire).<ref name = "techtermsdefinition">[https://www.techterms.com/definition/plugandplay Plug and Play Definition]</ref>