Contents of the _HEAPSWP.DOC file
HEAPSW.ARC _HEAPSWP.TPU is a Turbo Pascal 5.0 Unit that
allows your program to use the largest possible Heap space
and still be able to EXEC external programs by saving an
image of the Heap Space to disk and deallocating the Heap so
it may be used by another program. On return to the program
the Heap is restored to it's original state. Pascal programs
can use memory to the top of 640K and still shell out to
The files in this Archive are:
_HEAPSWP.TPU Turbo Pasal 5.0 unit to manage the Heap
_HEAPSWP.INT Interface section describe the procedures
and how they are used.
_HEAPSWP.DOC This document.
HEAPDEMO.PAS Source for the DEMO program which shows
how the routine is used in an actual
_DEMO.TPU Unit used by the HeapDemo program.
This program came about as a result of using dynamic
variables on the Heap to store lists of information for a
real estate program. The lists could get very large and
could take a long time to load.
Since they needed the maximum Heap space it became
impossible to run external programs or shell out to another
COMMAND.COM to take a look at directories or format a disk.
This unit saves the entire Heap area to the disk and then
Deallocates the memory for use by the program to be called.
The standard TP5.0 EXEC procedure is then used to run the
external program or a command.com.
When the user returns from the external program the Heap
memory is reallocated and retrieved from the disk. The swap
file is then erased.
About the only restrictions are that the disk have enough
room on it for the Swap file. See the _HEAPSWP.INT interface
file for details on how to use the routines.