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From: dmt@ahuta.UUCP (d.tutelman)
Newsgroups: net.micro
Subject: Re: an old idea whose time has come again
Message-ID: <377@ahuta.UUCP>
Date: Fri, 18-Jan-85 08:12:34 EST
Article-I.D.: ahuta.377
Posted: Fri Jan 18 08:12:34 1985
Date-Received: Sat, 19-Jan-85 01:17:17 EST
References: <593@houxn.UUCP>
Organization: AT&T Information Systems Labs, Holmdel NJ
Lines: 19

REFERENCES:  <593@houxn.UUCP>

Gee, diagnostics by ear.  I have a similar story from software development
for the #1ESS at the Indian Hill Bell Labs.  We could tell if our
software was about to crash the system if the relays in the trunk
circuits started clicking in a certain pattern. We could sometimes halt
things when they did that, in time to get a meaningful diagnostic
dump (which you couldn't do AFTER it crashed).  
The reason was that the system recovery software (NOT part of what
we were writing) was doing some reinitialization on the hardware if
our programs went just a little insane.

				Dave

PS - We also had an interesting visual diagnostic tool: an oscilloscope
set up to display memory references as X-Y points on the screen.
By watching the pattern on the screen, it was possible to detect
impending disaster even faster than by listening to the clicks;
however, you couldn't do this solo and still run the console.