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Q96560: POWER.EXE and Advanced Power Management (APM) Support

Article: Q96560
Product(s): Microsoft Disk Operating System
Version(s): MS-DOS:6.0,6.2,6.21,6.22
Operating System(s): 
Keyword(s): 
Last Modified: 19-NOV-1999

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The information in this article applies to:

- Microsoft MS-DOS operating system versions 6.0, 6.2, 6.21, 6.22 
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SUMMARY
=======

You can install the Power program (POWER.EXE) even if your BIOS does not support
the Advanced Power Management (APM) specification. After you install POWER.EXE
in the CONFIG.SYS file, the POWER command (without any switches) provides status
information.

On systems without APM support, POWER displays the following:

  Power Management Status
  -----------------------
  Setting = ADV:REG
  CPU: idle 90% of the time

On systems with APM support, POWER displays the following additional information
reported by the BIOS:

  Power Management Status
  -----------------------
  Setting = ADV:REG
  CPU: idle 90% of the time
  AC Status: OFFLINE
  Battery status: High
  Battery life (%): 90

MORE INFORMATION
================

POWER.EXE detects whether your system has an APM-compliant BIOS and then adapts
accordingly.

When POWER.EXE detects that your system is idle, it saves power by issuing a CPU
HALT instruction. HALT stops CPU execution until the next hardware interrupt
occurs (this is usually the timer interrupt, which occurs 52 times per second).
On systems without an APM-compliant BIOS, testing reveals a 5% power savings.

If your system has an APM-compliant BIOS, POWER.EXE communicates with the BIOS.
Depending on the frequency of the idle signals from POWER, the APM-compliant
BIOS can save power by shutting down the display or hard disk, switching the
processor to a slower speed, or suspending the system entirely.


Additional query words: 6.22 6.00 five percent 6.20

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Keywords          :  
Technology        : kbMSDOSSearch kbMSDOS621 kbMSDOS622 kbMSDOS620 kbMSDOS600
Version           : MS-DOS:6.0,6.2,6.21,6.22

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