Using Serial Communications Under Win32s

SUMMARY

Windows NT and Windows provide significantly different serial communications application programming interfaces (APIs). Win32s does not support the Win32 Communications API.

A good approach to take in writing a Win32-based application targetted for Win32s that uses serial communications is to create a pair of dynamic-link libraries (DLLs) with the same name. One DLL will use Win32 Communications APIs and be installed under Windows NT. The other DLL will use the Universal Thunk to call a 16-bit DLL that will call the Windows Communications API. This DLL will be installed under Win32s.

For more information on the Universal Thunk, see the "Win32s Programmers Guide" included with the Software Development Kit (SDK). In addition, there is a sample in MSTOOLS\WIN32S\UT\SAMPLES\UTSAMPLE.