🚀 go-pugleaf

Well, I've solved my own problem, and I post the solution in case
anyone else runs into the problem described in the original posting,
and in case some knowledgeable person can offer some further
clarificatory words.

Both Norton (Programmer's Guide) and Ray Duncan in the new *Advanced
MSDOS* (Microsoft Press, 1986) point out that the SS and SP registers
need to be saved into variables within the code segment before
executing the EXEC function call, and need to be restored from those
variables right after control is returned to the program. I had been
doing this right before pushing all the other registers onto the stack
in preparation for making the call itself. This worked, except under
the conditions described in the previous posting. I have since moved
the definition of these variables to right after the beginning of the
code segment in the same module, i.e., out of the proc that made the
EXEC call. This seems to work fine. I decided that this might be the
problem after determining that when push failed, it failed right after
stepping through the two defines, one for SP and one for SS. Right
after those two lines were "executed," the code seemed to return to the
caller: the rest of the proc never got executed. I'd appreciate hearing
form anyone with a firmer grasp of what really went wrong here, i.e.,
what the real pitfalls are in making this call, and I apologize to the
non-MASMers who might be reading this. Thanks in advance.



-- 
Charles Blair   			    ..!ihnp4!gargoyle!sphinx!cjdb
The University of Chicago		    lib.cb%chip@UChicago.Bitnet