OpenComm() and Related Flags Obsolete Under Win32 (94990)


The information in this article applies to:

  • Microsoft Win32 Application Programming Interface (API), when used with:
    • the operating system: Microsoft Windows NT 3.1
    • the operating system: Microsoft Windows NT 3.5
    • the operating system: Microsoft Windows NT 3.51
    • Microsoft Windows 95
This article was previously published under Q94990

SUMMARY

OpenComm(), a Windows 3.1 application programming interface (API), is obsolete under Windows NT and is not in the Win32 API. Note that the flags, IE_BADID, IE_BAUDRATE, IE_BYTESIZE, IE_DEFAULT, IE_HARDWARE, IE_MEMORY, IE_NOPEN, and IE_OPEN are obsolete, but are still in the header files.

OpenComm() is provided for 16-bit Windows-based applications running under Windows on Win32 (WOW).

MORE INFORMATION

Under Win32, CreateFile() is used to create a handle to a communications resource (for example, COM1). The fdwShareMode parameter must be 0 (exclusive access), the fdwCreate parameter must be OPEN_EXISTING, and the hTemplate parameter must be NULL. Read, write, or read/write access can be specified and the handle can be opened for overlapped I/O.

ReadFile() and WriteFile() are used for communciations I/O. The TTY sample program shipped with the Win32 Software Development Kit (SDK) demonstrates how to do serial I/O in a Win32-based application.
Modification Type:MajorLast Reviewed:4/15/2004
Keywords:KB94990
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