Using Fortran Source Code under Windows OOP Environment

In order to reuse the Fortran source code based on DOS system to solve the engineering process problem under Windows, the technique is discussed on how to use the DOS Fortran source code efficiently through an example. The efficient ways about creating Dynamic Link Library (DLL) with Microsoft PowerStation 4.0 and calling the Fortran subroutine or function located in DLL under other OOP development environments are proposed. The facts tells us the method is an efficient way in mixed programming between Fortran and other OOP languages.