Allocating More Than 64K of Memory in DOS

 

  PRODUCT  :  Borland C++                            NUMBER  :  705

  VERSION  :  2.0

       OS  :  DOS

     DATE  :  August 12, 1992                          PAGE  :  1/2

    TITLE  :  Allocating More Than 64K of Memory in DOS

  /************************************************************************

  This program demonstrates the dynamic allocation of a memory

  block larger than 64K bytes using farcalloc().  It should not be

  compiled in the Tiny memory model.  The program calls farcoreleft

  prior to allocating the block of memory to determine how much

  memory is available.  Note that this method will not be accurate

  if memory has been previously allocated and then released as the

  released memory is handled differently. If you choose to run this

  program from inside the integrated development environment you

  must set the head size under OPTIONS/DEBUGGER to at least the

  size of the two parameters passed to farcalloc() + 5 bytes. Also

  note that farcalloc can be interchanged freely with farmalloc or

  farrealloc in this example.

  ***********************************************************************/

  #include <stdio.h>

  #include <alloc.h>

  #include <string.h>

  #include <dos.h>

  #include <conio.h>

  int main(void)

  {

     int huge *fptr;

     unsigned long val;

     clrscr();

     /* Check the amount of memory available if no blocks have been

        freed */

     printf("\nMemory available on the far heap:   %lu\n",val =

             farcoreleft());

     /* allocate memory for the far pointer */

     fptr = (int huge *) farcalloc( 66000L, sizeof(int));

     /* display string (note the F modifier) */

     printf("Address of allocated block is:      %Fp", fptr);

  PRODUCT  :  Borland C++                            NUMBER  :  705

  VERSION  :  2.0

       OS  :  DOS

     DATE  :  August 12, 1992                          PAGE  :  2/2

    TITLE  :  Allocating More Than 64K of Memory in DOS

     /* Check how much memory is left */

     printf("\nMemory left on the far heap:        %lu\n",val =

               farcoreleft());

     getch();

     /* free the memory */

     farfree((int far *) fptr);

     return 0;

  }

  DISCLAIMER: You have the right to use this technical information

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

  you received with the Borland product to which this information

  pertains.