On Apr 26, 10:19, Bill Pechter wrote:
> I'm slightly puzzled by what you say about
DEC X-11, though. My
exposure
> to it and XXDP is only in the form of the
diagnostics available to end
> users and third-party service organisations, and I suspect there's more
to
> it than that. The reason I think of XXDP as the
OS and X-11 as the,
well,
> application in a way, is that all I see are the
X-11 modules to run
build
> and series of tests, whereas XXDP includes the
monitor, system handlers
etc
(as well as
the diagnostic programs and utilites, of course). To me,
that's the OS.
--
Pete Peter Turnbull
Network Manager
University of York
You're exactly correct, except the XXDP doesn't have drivers for
the comm gear and other stuff, whereas DECX/11 can have modules
running simulating disk and tape i/o, comm i/o and can do task
scheduling and timeouts. Also DECX/11 is interrupt driven where most of
XXDP polls status registers.
Yes, I knew about the polled operation.
I stretched my view a bit. DEC training called XXDP a
diagnostic
monitor... which was ok until the DS> diagnostic supervisor got loose...
and the names collided.
The XXDP monitor is single tasking, non-interrupt driven, polling and
can hang forever waiting for an event that never comes. DECX/11 won't.
DECX/11 seemed much more os-like. Batch streams do exist in XXDP
(the .ccc chain files) -- but that's just minimal scripting.
Yes, .ccc is of rather limited use. Enough for sets of diagnostics and not
much more, really.
Thanks for the information -- I'm enlightened. Did DECX/11 ever make it
outside of DEC's walls, other than in the form of strings of modules for
field confidence tests?
--
Pete Peter Turnbull
Network Manager
University of York