Advanced Configuration and Computer Power Interface (ACPI): ACPI is a Joint Microsoft/Intel/Toshiba specification for power management of PCs. It is required in PC99 compliant computers. Windows 98 and NT5.0 (Windows 2000) support support ACPI.

The idea is to provide a uniform way of handling automated power down of devices that are not in use, and power up of devices that may be needed when the computer configuration changes -- e.g. when a removable disk is inserted. ACPI requires support in the BIOS, OS device drivers and hardware. The On-NOW initiative for quick power up of devices when they are needed is supported. The Smart Battery SubSystem is supported

ACPI also includes architecture independent Plug And Play and configuration identification features. Some, but not all of the older (WIN95) power management functions, are supported in ACPI. Thus, if WIN98 is used with a non-ACPI compliant BIOS, power management may be degraded.

In ACPI, all user control of power management is supposed to take place in the OS. Prior to ACPI, power management was frequently set up in the BIOSes. It is likely that the changeover may result in some difficulties. Red ACPI Error screens indicate probable hardware/BIOS problems. Blue ACPI Error Screens indicate probable software problems. Not that you'll ever see an ACPI error screen of course.

The specification is available on the Internet.

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