🚀 go-pugleaf

In article <1992Oct28.123801.188905@ipgaix.unipg.it> luca@dedalo.unipg.it (Luca Priorelli) writes:
>Can anybody tell me if it is possible to call a 16 bit DLL from
>a 32 bit application?

Yes, if you have Watcom C-386, IBM C-Set/2, or the old MSC-386 from
the early OS/2 2.0 SDK.  You have to use the _far16 modifier when
declaring the function, and use _far16 in the declarations of
pointer parameters to the function (if any).  For example:

	extern int _far16 funky(char _far16 *p);

This causes the compiler to generate a 32-to-16-bit thunk and convert
the pointer parameter when it sees a call to funky().

BC++ for OS/2 will support this feature.  I don't know about emx, but
I don't think it supports it directly in the compiler; if this is the
case, you have to write your own wrapper functions in assembly language
that do the necessary thunking and conversion.  One way to find out
how to do this is to look at the output of a compiler that does it
automatically (warning: it's not a pretty sight).

For more examples of 16-bit function prototypes, see BSESUB.H in the
IBM toolkit.  This header file contains prototypes for the VIO, KBD,
and MOU subsystems, which are all 16-bit.  I believe that wrappers for
these functions are available for emx.