DosPortAccess

#define INCL_DOSDEVICES

USHORT  rc = DosPortAccess(Reserved, TypeOfAccess, FirstPort, LastPort);

USHORT           0;             /* 0 */
USHORT           TypeOfAccess;  /* Request or release */
USHORT           FirstPort;     /* First port number */
USHORT           LastPort;      /* Last port number */

USHORT           rc;            /* return code */