PRODUCT  :  C++                                   NUMBER  :  1764
  VERSION  :  3.1 & up
       OS  :  DOS
     DATE  :  January 11, 1994                         PAGE  :  1/2

    TITLE  :  VROOM Overlay swapping using XMS and EMS




  In tracking down problems with using Expanded or Extended memory
  swapping with VROOM overlays, there are a number of factors that
  can determine whether EMS/XMS memory will be available.  These
  factors include the memory manager(s) being used by the system,
  the switches passed to these memory managers, the total memory
  available, other programs using EMS/XMS, etc.

  Having a simple test program can sometimes prove valuable in
  tracking down such problems.  The following program provides one
  way to do this, and relies on the simple fact that the overlay
  swapping functions return zero if EMS/XMS are available.

  To compile and link these two files from the command
  line, use "bcc -ml -Y vroom1.c -Yo vroom2.c"

  /*
   * vroom1.c
   * a program for testing _OvrInitEms and _OvrInitExt
   * compile and link with vroom2.c as described above.
   */

  #include<stdio.h>
  #include <dos.h>

  /* function to be overlaid */
  extern void stub(void);

  int main()
  {
  if (_OvrInitEms(0, 0, 0) == 0)
          printf("\nOvrInitEMS returned zero.  Expanded memory
                  found.\n");
  if (_OvrInitExt(0, 0) == 0)
          printf("OvrInitEXT returned zero.  Extended memory
                  found.\n");
  stub();
  return 0;
  }

  /* vroom2.c
   * a stub so we'll have something to overlay
   */














  PRODUCT  :  C++                                   NUMBER  :  1764
  VERSION  :  3.1 & up
       OS  :  DOS
     DATE  :  January 11, 1994                         PAGE  :  2/2

    TITLE  :  VROOM Overlay swapping using XMS and EMS




  void stub(void) { }

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  subject to the terms of the No-Nonsense License Statement that
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