About Advanced Power Management

 As laptop computers gain in popularity the need to extend battery life has
 become acute.  And as people become more environmentally aware, we are
 seeing a greater need to conserve electricity, even on desktop models.

 Laptop makers have been using power-management techniques for some years,
 but it has been a haphazard affair, and there has been no way that an
 operating system or an application program can cooperate in reducing power

 In 1993, Intel and Microsoft announced the Advanced Power Management
 specification.  It describes a standard interface that allows the system
 BIOS, the operating system, and applications to work together to save

 Here's how application programs can become power-aware:

  Use INT 15H 5300H to see of APM services exist; if not forget it.
  Use INT 15H 5301H to inform the BIOS that you are savvy.
  Use INT 15H 5305H (CPU Idle) when you're waiting around for a
   keystroke or mouse click or other event.
  Use INT 15H 530bH (Get APM Event) and take action when requested.

See Also: APM API
          INT 15H (AT Extended Services)