VMS stability back in the day (was Re: NuTek Mac comes)

Alexander Schreiber als at thangorodrim.ch
Fri Jul 15 18:34:27 CDT 2016

On Fri, Jul 15, 2016 at 10:08:40AM -0400, Mouse wrote:
> > DECnet might be totally integrated and awesome, but it's also
> > proprietary, seldom used,
> I think it is only semi-proprietary.  I've seen open documentation that
> at the time (I don't think I have it handy now) I thought was
> sufficient to write an independent implementation, both for Ethernet
> and for serial lines.
> However, IIRC it also has a fairly small hard limit on the number of
> hosts it supports.  I don't remember exactly what the limit is;
> different memories are handing me 10, 12, and 16 bits as the address
> size, but even the highest of those is sufficient for at most a large
> corporation.  (Maybe it was 6 bits of area number and 10 bits of host
> number within each area?  I'm sure someone here knows.)


2^16 addresses for a large corp these days will just get you some howling
laughter. Depending on what the company does, it might be enough for the
desktops & their support environment, but not even remotely enough for
the datacenters ...

> Perhaps if DEC had enlarged the address space (somewhat a la the
> IPv4->IPv6 change) and released open-source implementations, it might
> have been a contender.  For all I know maybe they've even done that,
> but now it's much too late to seriously challenge IP's hegemony.

IP won over OSI *hualp* and whatever else insanity was out there because
it a) works, b) is reasonably simply to implement (yes, I know, a full up,
modern TCP/IP stack is anything but trivial, but the basics are not that
crazy) and comes with a rather low level of designed-in complexity.
Just compare SMTP and the OSI equivalent, X.400 ... yikes.
> But the real shining star of DECnet/VMS was not the protocols, but the
> ground-up integration into the OS.

Which in modern UNIX systems is also there for TCP/IP. A modern UNIX type
OS is pretty much unthinkable without a fully integrated TCP/IP stack.

Yes, I'm aware of Coherent and their TCP/IP stack being an option, but even
in the 90s I considered this to be a bad joke.

Kind regards,
"Opportunity is missed by most people because it is dressed in overalls and
 looks like work."                                      -- Thomas A. Edison

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