Using VxDs and Software Interrupts Under Win32s

ID: Q105760

The information in this article applies to:

Microsoft Win32s versions 1.3, 1.30a, 1.3c

SUMMARY

Calling VxDs directly from a Win32-based application is not supported under Win32s. Win32s does not support the VxD interfaces, so the call is handled by the underlying Windows system. The Win32-based application runs with 32-bit stack and code sections, but Windows expects only 16-bit segments. Therefore, the calls to the VxD cannot be handled by Windows as expected.

To call software interrupts (such as Interrupt 2F) from a Win32-based application running under Windows 3.1 via Win32s, place the call in a 16- bit dynamic-link library (DLL) and use the Universal Thunks to access this DLL. To convert the addresses between segmented and linear address, use UTSelectorOffsetToLinear() and UTLinearToSelectorOffset().

Additional query words:

Keywords : kbWin32s kbThunk
Version : WINDOWS:1.3,1.30a,1.3c
Platform : WINDOWS
Issue type :