Get drive info (INT 21h, EFh - Novell Advanced NetWare 1.0+)

        Entry:
          AH = EFh
          AL = subfunction
                 00h  Get drive handle table
                 01h  Get drive flag table
                 02h  Get drive connection ID table
                 03h  Get connection ID table
                 04h  Get file server name table
        Return:
          ES:DI -> shell status table