DOCUMENT:Q75742  03-NOV-1999  [win16ddk]
TITLE   :Display Driver Compatibility
PRODUCT :Microsoft Windows Device Driver Kit
PROD/VER::3.0,3.1,3.11
OPER/SYS:
KEYWORDS:

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The information in this article applies to:

 - Microsoft Windows Device Development Kit (DDK) for Windows, versions 3.0, 3.1, 3.11 
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SUMMARY
=======

Microsoft will strive to preserve compatibility of Windows 3.0 display drivers
with future versions of Windows. However, there are some basic guidelines that
must be followed to ensure full compatibility.

MORE INFORMATION
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To ensure full compatibility between Windows 3.0 display drivers and future
versions of Windows, adhere to the following guidelines regarding fonts and the
use of VDDs and grabbers.

Display drivers should use glyph caching, instead of caching the entire character
set. Display drivers that perform font caching may encounter conflicts with the
upcoming TrueType font technology. The Windows 3.0 8514/a driver source code is
a good sample of a driver that uses glyph caching. Additional information will
be available in a future Windows device development kit (DDK).

Always use grabbers and VDDs from the same Windows version. Windows 3.0 VDDs and
grabbers may not be compatible with their counterpart components from future
versions of Windows. For example, do not run Windows 3.0 grabbers with Windows
3.x VDDs. Likewise, do not run Windows 3.0 VDDs with Windows 3.x grabbers.

Furthermore, a third-party device driver designed to work with a grabber or VDD
from Windows 3.0 may not be compatible with the same grabber or VDD from future
versions of Windows. For example, a grabber designed to work with the standard
VGA VDD included in Windows 3.0 (*VDDVGA) may not be compatible with the
standard VGA VDD included in Windows 3.x.

Third-party display-driver OEM setup disks should include all appropriate VDD and
grabber files (regardless of whether or not the files are included on the
Windows 3.0 setup disks), and should not require any changes. Unfortunately,
some vendors do not ship VDD and grabber files that are already available on the
Windows 3.0 setup disks.

Driver installation disks that provide a proprietary VDD, but rely on standard
Windows 3.0 installation disks for a grabber, should be rebuilt to included the
necessary grabber to ensure compatibility with future versions of Windows.

Likewise, driver installation disks that provide a proprietary grabber, but rely
on standard Windows 3.0 disks for a VDD, should be rebuilt to include the
necessary Windows 3.0 VDD in order to ensure compatibility with future versions
of Windows.

Additional query words: 3.10 3.11 virtual

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Keywords          :  
Technology        : kbAudDeveloper kbWin3xSearch kbWinDDKSearch kbWinDDK300 kbWinDDK310 kbWinDDK311
Version           : :3.0,3.1,3.11

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