The Role Of Plug-And-Play (Pnp) Traditional PCs used devices that required manual configuration—each IRQ, DMA, IO port, and memory address space had to be specifically set through jumpers on the particular device. If you accidentally configured two or more devices to use the same resource, a conflict would result. This would require you to isolate the offending devices, identify available resources, and reconfigure the offending devices) manually. Taken together, this was often a cumbersome and time-consuming process. In the early s, PC designers realized that it was possible to automate the process of resource allocation each time the system initializes. This way, a device needs only to be installed, and the system would handle its configuration without the assistance or intervention of the installer. This concept became known as “Plug-and-Play” (PnP), and it is now standard in the PC arena. PnP systems require three elements to function - PnP-compliant devices (such as video boards, modems, drive controllers, and soon- PnP-compliant BIOS (now used in all Pentium-class systems. - PnP-compliant operating systems (like Windows 95).
