2 Jul
2016
2 Jul
'16
11:43 a.m.
On Sat, 2 Jul 2016, Chuck Guzis wrote:
Of course, this only works when the program
doesn't clobber its own
initialization code (to reclaim memory), which a lot of programs did in
those memory-limited days.
OR, as part of the program's initialization code
(starting at 100h) it
clears the areas of the TPA used for holding the data/text/etc. that the
program is working on.
Regardless, neither CP/M-80 nor MSDOS requires that a
.COM file have any
particular structure--even MSDOS will try to run a zero-length .com file
without complaint.
It was difficult to convince my students that they could not rely on
memory being zeroed out before their programs ran.
"Yes, it worked. Good start. But will it work RELIABLY if you run it
again, or run it after somebody else's program runs?"
--
Grumpy Ol' Fred cisin at xenosoft.com