I'm using the old g77 compiler (http://people.tamu.edu/~matthewmccleskey/g77.html) but can't seem to find out how to use external DLLs in my code. Is it even possible, or would I have to get a newer compiler?
I have both DLL and LIB file.. The function is named GetDBI (_GetDBI@32).
Is it even possible to use DLLs in fortran 77?
You seem to be using Windows, where one problem is that there's a plethora of ABI's to choose from. AFAIK g77 supports only the default one that the accompanying gcc supports (cdecl?). There are also some issues with COMMON (static) data in DLL's on Windows, AFAIK.
The successor of g77, gfortran, has some support for different calling conventions as well as handling of common and module variables in DLL's, see http://gcc.gnu.org/onlinedocs/gfortran/GNU-Fortran-Compiler-Directives.html