GENERAL NOTES FOR PROTECTED MODE PROGRAMS


            There are  a few  basic differences  between real  mode  and
            protected mode  that need  to be addressed to convert a real
            mode program to run in protected mode.

            Programs run  at a  protection level that prevents them from
            executing privileged  instructions such  as lgdt, lidt, etc.
            The DPMI  interface is  the only method application programs
            have for modifying system structures such as descriptors.

            While DPMI  defines a specific set of functions that will be
            supported  by   all  implementations,  there  may  be  minor
            differences  in  individual  implementations.    Programmers
            should refer  to the notes for their DPMI implementation for
            documentation on  detecting  the  presence  of  and  calling
            vendor specific  extensions.   However, any application that
            is written to adhere only to standard DPMI calls should work
            correctly under all implementations of DPMI.