Some applications  require the ability to allocate memory in
            the real mode addressable 1 megabyte region.  These services
            allow protected  mode  applications  to  allocate  and  free
            memory that  is directly  addressable by  real mode software
            such as networks and DOS device drivers.  Often, this memory
            is used  in conjunction with the API translation services to
            call real  mode software  that is  not directly supported by
            DPMI.