Microsoft KB Archive/11815

DOS, XENIX Place STACK in DGROUP

PSS ID Number: Q11815 Article last modified on 01- 6-1989

3.3x XENIX docerr

Question: On Page 75 of the “Microsoft FORTRAN User’s Guide,” the manual displays a memory map for the STACK entry. It states that the STACK is provided for compatibility with MS-DOS and that under XENIX, the STACK is reserved by it and not in DGROUP. However, when you use the -F option to set the STACK, the effect is as if the STACK is in DGROUP. For example, setting the STACK larger makes the heap smaller (I receive out-of-heap errors); making the STACK smaller makes the errors disappear. Perhaps the -F option not only affects the XENIX STACK, but also the DOS compatibility STACK. Is this the case?

Response: The information on Page 75 is incorrect. Both DOS and XENIX place the STACK in DGROUP. The documentation implies that there are two STACKS, when in fact, there is only one. For this reason, the heap is reduced when the STACK size is increased.