14 Dec
2022
14 Dec
'22
5:54 p.m.
arnold(a)skeeve.com writes:
Andrew Warkentin <andreww591(a)gmail.com> wrote:
In that time frame there was a number of microkernel designs. One that
has not been mentioned was OS-9 for the 6809/68000 processor. I used it
pretty extensively. OS-9 was very unix like from the userland POV, when
you consider something like V5 unix, however it didn't share any of the
same command names, just many of the same concepts. It was close enough
that if you had the C compiler, a very basic K&R compiler, you could get
some of the unix command to compile without too much trouble. I ported
sed from the DEC user's group source and the termcap library from BSD
and created a varargs library for it. OS-9 was very microkernel and
nothing like Mach or even Minix. It was also very much positioned to
real time OS needs of the time and was not really marketed generally and
unless you happened to have a Color Computer from Radio Shack or was a
part of the nitch they served you would probably have never come across
it and it would have seemed to be expensive to acquire. It was very
clean, but you needed to know 6809 or 68000 assembly to create anything
new for the OS itself, although at least one person had figured out how
to use the C compiler, sort of, to produce assembly that could be
assembled into device managers and device drivers.
--
Brad Spencer - brad(a)anduin.eldar.org - KC8VKS - http://anduin.eldar.org
Yes, I agree 100% that Mach is a complete and
utter failure as a
microkernel, and seems to have almost single-handedly destroyed the
reputation of microkernels. I don't get why everyone was so focused on
Mach-like kernels when there was a better alternative that had been
around in some form for almost a decade before Mach (QNX wasn't the
first of its kind; it seems to have had pretty significant influence
from Thoth).
I suspect because Mach was available if you had the right Unix licenses
and because it was hot in the research world in the mid 80s. Researchy
types tend to look at what other researchers are doing / using, it seems
to me often without knowledge of or caring about what people are using
in industry. (My two cents, from having worked at universities.)
Arnold