CI's, Unix, VMS

[leichterj at rani.DEC]

Ah, rumors and lack of information!

> Newsgroups: net.unix-wizards
> Path: decwrl!sun!qubix!ios!oliveb!hplabs!hao!seismo!rochester!cmu-cs-pt!avie
> Subject: Re: raw rumour: VAX 8600 & Ultrix
> Posted: Mon Dec  3 19:39:11 1984
>
> I may not have all my facts totally correct, but here goes anyway.
To paraphrase someone - Mark Twain? - it's not so much what you don't know as
what you know that isn't so.

> Running Unix (or Ultrix) on a 8600 is not as simple as just writing a
> simple device driver to talk to the CI.  Remember that the CI is this
> "intelligent" device that lets a Vax cpu talk to it at a very high
> level.  It is my understanding that VMS actually gives "filenames" to
> the CI to be processed.  Unfortunately, there are two problems.  The
> first is that Unix file names don't look like VMS file names.  The
> second is that information about the CI is hard to come by.
>
> ...
>	Avie

(a)  The CI isn't a "device" in anything like the sense you seem to have in
mind.  "CI" stands for "Computer Interconnect".  A CI is similar to a Unibus
or Massbus.  What you meant to say was that the HSC-50 - "HSC" is Hierarchical
Disk Controller - talks to a CPU - known to the guys who develop such things
as a "compute server" :-) - at a pretty high level.  However...

(b)  The HSC-50 is a DISK server, not a FILE server.  It knows nothing about
file structures, file names, or directories.

(c)  Do you claim that "CI" (and HSC-50) documentation is harder to come by
than is the usual case for low-level information of this type?

> Newsgroups: net.unix-wizards
> Path: decwrl!decvax!wivax!cadmus!harvard!seismo!brl-tgr!tgr!God
>	<root%bostonu.csnet at csnet-relay.arpa>
> Subject: Re: Hacking OS sources
> Posted: Thu Dec  6 10:29:50 1984

> RE: Buying and hacking VMS sources...
> 
> I started to look into this to as we had some significant
> misfeature problems under VMS, like no CBREAK mode
> (ie. no XON/XOFF while passing chars reads, we want to
> use things like EMACS over our flow controlled tty net.)
Even in VMS V3, it's not THAT hard to use binary mode or out-of-band interrupts
for this purpose; but in fact VMS V4 has a "PASTHRU" mode which does exactly
what you want.  Yes, VMS evolves.

> It seemed to me that:
> 
> 	a) Yes, it is expensive but that's all relative.
> 	b) It's more than you think, as it is written
> 	in a few languages and you have to have and
> 	support all those languages just for this one
> 	purpose (eg. BLISS)
MACRO, which comes with the system, plus BLISS, will cover just about every-
thing.  There are probably a couple of exceptions - but that's what you get
when you have a system that really and truely supports a common language envi-
ronment - pieces get written in the most appropriate language, and they work
together.

> 	c) I heard (tell me if I'm wrong) that a sysgen
> 	from source can take many many hours on a 780
> 	and basically requires all those to be standalone.
> 	(I guess we could call buying a spare 780 just
> 	another expense.)
Very true.  But why would you want to rebuild the ENTIRE system?  Any well-
designed system is modular - you re-compile what you've changed, not all the
stuff that is constant.  This modularity includes the kernel and the device
drivers.

> ...
> Similarly, you COULD put the VMS manuals on-line but they were
> never designed to be on-line and would require something much
> more sophisticated than the UNIX 'man' command to make it useful.
> ...
There is a fundamental difference between the VMS philosophy of "documentation
as tutorial" and the Unix one of "documentation as reference".  It really
wouldn't make much sense to keep it all on-line, even if you could afford the
disks - something like 150,000 blocks, as I recall.  What you have on-line is
a help system that in practice provides all the "reference" information you
need most of the time - and is generally much easier - and MUCH faster - to
use.  (To use a Unix analogy, I can get information about the stty -raw switch
directly - by typing HELP SET TERMINAL/PASSALL - without having to read three
pages of stty stuff.  I can get THAT on VMS by typing HELP SET TERM QUALIFIERS.)

> 			-Barry Shein
							-- Jerry