APM/ACPI BIOS questions
#56835 by rfdes
Wed Aug 24, 2011 10:24 pm
Hi -
I am looking for someone that is intimate with the antiquated 'Advance Power Management'
spec for power management prior to ACPI. I have a need to patch my current bios (a '98
vintage Tek Logic Analyzer) that when upgraded from Win98 to Win2000, the Power button
no longer automatically shuts down the computer. When I upgraded to Win2000, I also could
not force a power off of the computer when performing a 'START/SHUTDOWN' mouse sequence. The
OS would go forward with the shutdown of all applications and other housekeeping, but would
not automatically power off the computer without a BSD situation. I managed to discover
the bug in the bios firmware that prevented this from occurring and made the repair. I now can
shutdown/power off from the 'START/SHUTDOWN' mouse sequence. However, I still cannot get
the power button to initiate the shutdown sequence.

After studying the APM V1.2 spec, I do not understand the sequence of APM events that must occur to
trigger the OS to begin a smooth shutdown of he computer.

Here is what I think needs to happen:
OS polls bios every 1 sec asking for PM events.
Firmware detects power button pressed and sends 'Power Status Changed' event
OS polls bios asking for 'Power Status'
Bios responds with 'AC OFF'
OS begins smooth shutdown/power off sequence.

Anyway, I wanted to understand exactly how to implement a shutdown/power off sequence using
the APM interface. If anyone knowledgeable could lend me some advice, I certainly would appreciate


Edit - Removed the OP's e-mail address. KW