Yes, they are special, but...

[Barry Margolin <barmar@THINK.COM>]

    Date: Fri, 9 Jun 89 09:16 CDT
    From: ai.gooch@mcc.com (William D. Gooch)

	...."highly specialized hardware"....

    I've heard this idea bandied about enough that I suppose I should
    understand it by now, but - sorry if I'm being dense - I still don't
    know what it means.  The term "specialized," usually stated as in
    opposition to "general-purpose," implies that there are things one
    cannot do on a Symbolics machine which other hardware does support.
    If you don't mind my asking, what are those things?  

It's not that Symbolics machines can't do things that other machines
can, it's that they don't do many common things well.  Symbolics
machines are optimized for Lisp processing, and perform poorly at just
about everything else.  I/O performance is abysmal.  It doesn't matter
how fast you can do generic arithmetic if the machine grinds to a crawl
when it pages.  They claim that they run C code at about the same speed
as a Vax 11/750; meanwhile, Sun-4 users have desktop machines that get
at least 5 times that performance for a fraction of the cost.  The Suns
even beat the pants off them in Lisp processing; our code runs in both
Genera and Lucid, and compiles and loads several times faster in Lucid.

Note that in the above comparisons, the Symbolics machines are 3600
series, not Ivory machines.  I don't know whether they've improved the
I/O performance in the XL400.

I love my Lispm, and won't give it up.  It's a great hacker workstation,
and I love poking around in Genera.  But to be called "general purpose",
a machine has to perform reasonably at lots of different tasks, and
these machines don't.

                                                barmar