Microsoft KB Archive/224152

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DOC: Windows 95/98 Don't Use the Display Driver's FastBorder Interface

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Q224152

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The information in this article applies to:


 * Microsoft Windows 98 Driver Development Kit (DDK), on platform(s):
 * the hardware: Intel x86
 * Microsoft Windows 95 Driver Development Kit (DDK), on platform(s):
 * the hardware: Intel x86

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SUMMARY
The Windows 95 DDK and the Windows 98 DDK documentation omit any reference to the still-required FastBorder Device Driver Interface (DDI). This DDI is no longer used by the Windows 95 or Windows 98 operating systems components such as GDI or USER, but Microsoft Active Accessibility still requires that the FastBorder DDI be exported at ordinal 17 by the display system drivers.

MORE INFORMATION
The Windows 95 and Windows 98 operating systems don't call into the display driver's FastBorder Device Driver Interface (DDI). Instead, the operating system synthesizes the functionality by using more fundamental display system DDI routines.

Nevertheless, the Windows 9x DIBEngine DLL (DIBEng.DLL) still exports the related DIB_FastBorder entry point in order to support display minidrivers that still use it. DIBEngine will immediately fail the call and return if its used. Furthermore, the Microsoft Active Accessibility extensions to the operating system assume that the FastBorder DDI is still exported at ordinal 17.

Display systems that fail to provide the FastBorder DDI at ordinal 17 (either by omission or substituting another DDI at ordinal 17) break most Microsoft Active Accessibility applications.

Display system developers should consider the sample driver code in the Windows 9x DDK(s) as part of the documentation. Make sure your DDI exported routines replicate the sample driver export ordinals in order to avoid incompatibilities such as this. Adding new DDI on to the end of the ordinal list should be fine, but avoid replacing any existing ordinal exports.