A design philosophy and set of specifications for PC architectures that enables computer hardware, peripherals, device drivers, and operating systems to be easily reconfigured with minimal user understanding and intervention.
Plug and Play frees users from having to manually configure devices and device drivers when they add or remove peripherals from computer systems. For example, to configure a non–Plug and Play sound card, a user typically has to manually change jumpers or dual inline package (DIP) switches on the sound card itself, a task that is often difficult for the inexperienced user.
With Plug and Play, you simply plug in the device and follow a series of prompts (if any are necessary) to configure the appropriate drivers for your device.
A true Plug and Play system consists of the following three elements:
If a system does not support all three of these features, it is not truly Plug and Play, although it might have some limited Plug and Play support. In a completely Plug and Play system, these features work together to automatically enumerate (identify) new devices installed on or connected to the system, determine their resource requirements, establish a system configuration that can support these requirements without device conflicts, program the devices as necessary and load their device drivers, and notify the user of the changes to the system’s configuration.
The Windows 95 and Windows 98 components that work together to support Plug and Play include the following:
When you add a new hardware device to a Plug and Play system, the Add New Hardware Wizard starts and installs the necessary drivers for the hardware. The wizard selects suitable hardware resources for the device, which might include an IRQ line, I/O address, direct memory access (DMA) channel, and memory range. If the system cannot properly detect the hardware, you can manually run the Add New Hardware Wizard to configure the hardware.
Be sure that the new device is attached to the computer and is turned on before you run the Add New Hardware Wizard.