Unix versions

From: Bill Pechter <pechter_at_pechter.dyndns.org>
Date: Fri Apr 26 09:19:51 2002

> On Apr 25, 18:20, Bill Pechter wrote:
> > > On Apr 24, 21:05, Bill Pechter wrote:
> > >
> > > > Isn't it a bit much to call XXDP+ an OS.
> > > > DECX-11 is closer... XXDP's pretty dumb.
> > >
> > > I've always thought of XXDP as the OS that DECX-11 runs under.
> > More like the program loader for the OS... 8-).
> >
> > At least CP/M had better editors available than XXDP...
> Yeah, you mean EDLIN :-) TECO in XXDP is not my favourite editor!
> 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.

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.


  d|i|g|i|t|a|l had it THEN.  Don't you wish you could still buy it now!
Received on Fri Apr 26 2002 - 09:19:51 BST

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