Function            isXMSinstalled - is XMS installed

  Syntax              boolean isXMSinstalled(void);

  Prototype in        doshk.h

  Remarks             checks if the eXtended Memory Specification driver
                      HIMEM.SYS or some compatibile is available. At this
                      time, HIMEM 2.06 is the latest version.

  Return value        returns TRUE if XMS is available, FALSE otherwise.

  Example             #include <doshk.h>

                      main()
                      {
                           printf("XMS is ");
                           if (! isXMSinstalled())
                                printf("not ");
                           printf("installed\n");
                      }