Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!bloom-beacon!husc6!yale!mfci!rodman
From: rodman@mfci.UUCP (Paul Rodman)
Newsgroups: comp.arch
Subject: Re: In defense of the VAX
Message-ID: <667@m3.mfci.UUCP>
Date: 24 Feb 89 14:57:06 GMT
References: <11037@tekecs.TEK.COM> <76700073@p.cs.uiuc.edu>
Sender: rodman@mfci.UUCP
Reply-To: rodman@mfci.UUCP (Paul Rodman)
Organization: Multiflow Computer Inc., Branford Ct. 06405
Lines: 55

In article <76700073@p.cs.uiuc.edu> gillies@p.cs.uiuc.edu writes:
>
>
>1.  I seem to remember from my OS class that the vax virtual memory
>system was quite an innovation.  I don't know about VM in today's
>machines -- do they do it any *BETTER*?
>

Well you remember wrong. Prime Computer was selling p400 systems that
put "multic-in-a-matchbox" LONG before DEC got the vax out. The vax
was a *response* NOT an innovation in vm.

>2.  The VAX taught us to build RISC's.  It was very successful at that.
>3.  The VAX taught us to hate heavyweight procedure calls.
>4.  The VAX taught 32000 designers how to architect their machine.

Oh, good. lets admit that we can't do good engineering except by
correct obvious screw-ups.

>5.  The VAX was made to sell in 1978.  Ok, Flame ON!  Have you GOT ANY
>FRIGGING IDEA HOW EXPENSIVE MEMORY WAS IN 1978????  PEOPLE NEEDED TO
>USE IT IN 1978, OK???  CAN YOU PARSE THAT????  Flame off.  Other

Yes, as a matter of fact I do. I built a machine with 2102's in it,
remember them? 1kx1 for $6. We had moved by 1978 and 16kx1 drams were
being used. It is my opinion that a small increase in the text size
of vax programs would have been a good tradeoff vs byte aligned instrs.
At the time, I worked at such a company, PRIME, and whilst icky for
assembly language it was not nearly as difficult to pipeline. The
loss in bit efficiency wasn't the end of the world. 

When building a computer indended to have such a long life, you can't
be nano-hacking the architecture with things you'll regret later.

>companies in 1978 (Xerox), full of smart people, were architecting
>machines under the same assumptions as the VAX, and came up with
>worse/more restricted results (DLions).

Oh, ok. You've got another example of a large group of cooks spoiling
the broth..thank you for this support.
>
>5.  The VAX was AMAZING when it came out.  It created the "supermini"
>class of machine, as the first such computer from a major manufacturer
>(sorry, Gould / Perkin-Elmer).  How quickly we forget all this...
>
Hmm, well, *blush* I remember when DEC presented the vax and also being
impressed. Of course, I was a little damper behind the ears then and
hadn't designed any complex machines......

Flame on folks..................



    Paul K. Rodman 
    rodman@mfci.uucp