When using gsos2.exe with gsdll2.dll, reducing the size of the 
page bitmap will result in the error 
    Failed to decommit memory in pm_alloc_bitmap, rc = 87
The following patch fixes this.

*** gdevpm.c	Tue Sep 17 18:00:10 1996
--- ../gdevpm.c	Wed Dec 04 13:01:15 1996
***************
*** 1087,1093 ****
  	}
  	/* Shared memory can't be decommitted */
  #ifdef __DLL__
! 	if (needed < pmdev->committed) {
  		/* decommit memory */
  		if (rc = DosSetMem(pmdev->bitmap + needed, 
  			pmdev->committed - needed, 
--- 1087,1093 ----
  	}
  	/* Shared memory can't be decommitted */
  #ifdef __DLL__
! 	if (pmdev->dll && (needed < pmdev->committed)) {
  		/* decommit memory */
  		if (rc = DosSetMem(pmdev->bitmap + needed, 
  			pmdev->committed - needed,