DOCUMENT:Q86831  10-OCT-1999  [win95x]
TITLE   :32-Bit Disk Access and Western Digital 1003 Controller Cards
PRODUCT :Microsoft Windows 95.x Retail Product
PROD/VER:WINDOWS:3.1,3.11
OPER/SYS:
KEYWORDS:

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The information in this article applies to:

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

The Microsoft Windows version 3.1 32-Bit Disk Access feature actually performs
16-bit input/output with the Western Digital 1003 hard drive controller card and
compatibles.

MORE INFORMATION
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Microsoft Windows 3.1 ships with one Virtual Hard Disk Controller Device, which
is WDCTRL. WDCTRL supports hard-drive controllers that are compatible with the
Western Digital 1003 standard. This standard is a 16-bit standard.

The 32-Bit Disk Access feature is a series of layered virtual device drivers. The
higher-level virtual device drivers send their requests down to the virtual
device driver, which actually talks to the hard disk controller, that is,
WDCTRL. The communication between virtual device drivers is 32-bit data. The
virtual device driver that communicates to the hard disk controller can use
16-bit or 32-bit input/output.

Currently WDCTRL is using 16-bit input/output because it was written specifically
for the Western Digital 1003 16-bit standard. To achieve true 32-bit
input/output, a hardware manufacturer would have to write a low-level virtual
device driver that communicates to a specific hard drive controller that is
32-bit. Currently Microsoft only provides the WDCTRL.

Additional query words: fastdisk 3.10

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

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