This statement defines the size of the application's local heap in bytes. This value affects the size of the automatic data segment.
The field <bytes> contains any positive integer. You can enter <bytes> in decimal, octal, or hexadecimal radix. See Entering Numeric Arguments.
Instead of entering a number for <bytes>, you can enter the keyword MAXVAL. This sets the heap size such that the default data segment DGROUP is exactly 64K. MAXVAL is useful in bound applications in which you want to force a 64K requirement for DGROUP.
Example
HEAPSIZE 4000
This example sets the local heap to 4,000 bytes.