Advanced Power Management

Advanced Power Management (APM) is a power management API developed primarily by Intel and Microsoft and released in 1992, it allows an operating system to control the power management features available with each hardware part in a somewhat hardware independent fashion by using BIOS calls rather than having to write a driver for each individual feature. The APM Standard Revision 1.2 released in 1996 was the last version of the specification but most or all of the features presented there appear as a portion of the later ACPI which is replacement for APM and sundry related hardware control APIs.

Despite being developed by Microsoft APM support was always rather sketchy on operating systems delivered by the company, Windows NT for instance has no APM implementation at all, for that reason not all hardware providers supported the standards, but most did especially in the notebook sector and examples of APM support can be found in relatively recent notebook products.

Specification

 * 1.0 - Jan 1992
 * 1.1 - Sep 1993
 * 1.2 - Feb 1996

Publications

 * Frank J. Schroeder: Making Your OS/2 Device Driver APM-Aware
 * Intel; Microsoft: Advanced Power Management (APM) BIOS Interface Specification - Revision 1.2, February 1996