Newsgroups: comp.lang.lisp
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From: jeff@aiai.ed.ac.uk (Jeff Dalton)
Subject: Re: Why do people like C? (Was: Comparison: Beta - Lisp)
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References: <38mv58$gs2@peaches.cs.utexas.edu>> <CyCHCt.73w@cogsci.ed.ac.uk> <BUFF.94Oct28135705@pravda.world>
Date: Wed, 2 Nov 1994 18:35:29 GMT
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In article <BUFF.94Oct28135705@pravda.world> buff@pravda.world (Richard Billington) writes:
>In article <CyCHCt.73w@cogsci.ed.ac.uk> jeff@aiai.ed.ac.uk (Jeff Dalton) writes:
>
>   In article <38mv58$gs2@peaches.cs.utexas.edu> gadbois@cs.utexas.edu (David Gadbois) writes:
>   >William D. Gooch <goochb@swim5.eng.sematech.org> wrote:
>   >>[...] I disagree with the statement that "The specialized /
>   >>micorcoded machines should do worse than CISC machines against RISC."
>   >
>   >I would hate to see the Lisp machines being misremembered as being
>   >just about performance.  Sure, they were better or at least
>   >competitive with "stock" hardware in terms of price/performance up
>   >until the mid to late 80's.  But, IMHO, the main advantage was the
>   >safety of the hardware/software environement -- you had to work really
>   >hard to write code that would randomly corrupt and crash things.
>
>   I wonder about this.  I didn't use our Symbolics machine very
>   much, but it did seem moderately easy to get it into an odd state.
>   (Not nearly so easy as with D-machines.)  Moreover, your Lisp code
>   could do something that required a reboot.  With an ordinary OS
>   (Unix), your Lisp process might get messed up but everything else
>   sailed on regardless.
>
>This is a real waste of bandwidth, but:

I don't think so.  I'm glad you posted this article, at least.

>I've used Symbolics for over 11 years. I've occasionally used
>unix-based lisps, and I've used MCL a moderate amount recently. Yes,
>you can wedge a lisp machine, but the number of times I've not been
>able to recover at least to the point of saving work is less than 5. 

But it looks like you know a lot about Symbolics machines.
What about people who don't?  Our Symbolics once sat idle
for a couple of weeks becuase of an error it could recover
from if you just pressed the "proceed" key!  None of our
regular Symbolics users knew what to do about it!

(I wasn't involved.  I hardly ever used the Symbolics because
it was always being used by these other guys to run Art and
such stuff.)

I've heard a number of stories by now of Lisp machines sitting idle in
dusty corners because no one knew how to use them well enough to be
lured away from other machines.

>I did support for two different AI labs, and I'm including being unable
>to save other people's work as well in that number. There's a
>FEP-level debugger, if you're desparate, and almost always a warm-boot
>gets you close enough back to where you were that it's ok. In other
>environments, you wedge lisp and bang (at best) you're staring at the
>unix prompt wondering where everything went and why, and cursing
>'cause you've got to reload everything to get back to where you were -

People have very different perceptions of Sylbolics machines.
I'm perfectly willing to accept that you found then to be excellent,
but other people found them found them tricky to use and preferred
mainstream workstations.  Perceptions of *those* machines also vary.

For instance, my perception of Unix machines seems to be very
different from yours.  I don't think I've ever found myself back at
the Unix prompt wondering where everything went and cursing 'cause I
had to reload.

I have occasionally -- but vary rarely -- found myself back at the
Unix prompt instead of in the Lisp debugger.  But I don't curse
because I have to reload.  Indeed, I prefer to start over in a
clean image fairly often.

>at worst (and this has happened to me) you end up staring at the
>monitor prompt and realizing that you have to reboot unix (or the mac
>- and this happens real often) as well.

Maybe that happens a lot on the Mac.  It hasn't been a significant
problem on machines I've used.

>As far as I'm concerned there's one thing that killed the Symbolics:
>stupid management (most esp. in the early years). I learned from it
>that even if a company has absolutely the best product bar none, don't
>invest in it unless they've got great management.
>
>There are lots of reasons to use lisp on "stock" hardware as opposed
>to a Symbolics: reliability, however, is far and away the least of
>them.

I take your point that they're reliable, but I'm not sure bad
management was the only problem.  

-- jeff
