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Q82418: 32-Bit Disk Access and Portable Computers

Article: Q82418
Product(s): Microsoft Windows 95.x Retail Product
Version(s): WINDOWS:3.1,3.11
Operating System(s): 
Keyword(s): 
Last Modified: 01-OCT-1999

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The information in this article applies to:

- Microsoft Windows versions 3.1, 3.11 
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SUMMARY
=======

32-Bit Disk Access should not be used on battery-operated portable computers
that implement power-saving features. Enabling 32-Bit Disk Access on such
machines can cause Microsoft Windows version 3.1 to stop responding (hang).

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

Enabling 32-Bit Disk Access causes Windows to access the system's hard disk(s)
using an Enhanced mode virtual device driver (VxD), which accesses the
controller hardware directly. To function correctly, the disk controller must be
completely compatible with the standard Western Digital hard disk controller
architecture. In most cases, Setup and the VxD's own initialization code
properly detects those controllers that are not 100% compatible with the Western
Digital standard. The disk controllers used in portable computers are very
similar to Western Digital controllers but have extensions used for power
management, such as shutting down the disk drive when it hasn't been used for a
while or when the machine is placed in suspend mode by the user (typically by
pressing a button). Some machines, such as Tandon notebook computers, change the
state of the disk controller when the power source is changed from line to
battery. Basically, the power management support can change the state of the
disk controller without notifying Windows.

Since there is no standard for this hardware, the 32-Bit Disk driver cannot
determine when power-management events have occurred or what to do about them.
If the driver determines the controller is in a different state than it
expected, it will produce an error message. If this message is encountered,
32-Bit Disk Access should be turned off.

If Windows cannot be started in Enhanced mode while 32-Bit Disk Access is
enabled, Windows should be started with the command line,

  WIN /D:F

The switch temporarily disables 32-Bit Disk Access. 32-Bit Disk Access should
then be turned off permanently by using Control Panel's Virtual Memory dialog
box.

Controllers that support drive spin-down, such as Compaq's 386N computers, should
not use 32-Bit Disk Access for similar reasons.

NOTE: To avoid problems with these machines, 32-Bit Disk Access is disabled by
default. If the machine is not a portable and does not support spin-down, then
32-Bit Disk Access can be enabled.

Additional query words: 3.10 32 fast disk lte/25c docking station lte Compaq 486N 3.11 laptop lap top fastdisk

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Keywords          :  
Technology        : kbWin3xSearch kbZNotKeyword3 kbWin310 kbWin311
Version           : WINDOWS:3.1,3.11

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