PMMIOPROC

Pointer to an I/O procedure entry point.

typedef MMIOPROC FAR *PMMIOPROC;

All I/O procedure messages are passed to an I/O procedure using this interface. The syntax for a direct I/O procedure call is shown below.

typedef LONG (APIENTRY MMIOPROC)
                                (PVOID pmmioinfo,
                                 USHORT usMsg,
                                 LONG lParam1,
                                 LONG lParam2);