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

consumption.

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

power.

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)

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