Display Driver Compatibility

• Microsoft Windows Device Development Kit (DDK) for Windows version 3.0, 3.1, and 3.11

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

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.