Subject: Re: Garbage hunting
From: (Rob Warnock)
Date: 1999/01/07
Newsgroups: comp.lang.lisp
Message-ID: <771c8i$>
[off-topic alert...]

Paul Fuqua  <> wrote:
| I believe I remember someone hacking something up on a TI Explorer that
| would play disk-like sounds through the speaker.  He'd just moved to a
| site that kept all the system units in a machine room.  Run lights are
| nice, but that audible feedback really got your attention.

Circa 1965, I connected a speaker to the "Zero Balance" light[*] on an
IBM 1410, which let us hear the non-linear regressions converging towards
a solution -- the "chomping" noises got faster and faster as it converged.
If it was still taking ~10 seconds or so per "chomp", you knew you had
plenty of time to go get a cup of coffee and still get back before it was
done. If they were coming about a second apart, you knew it was time to go
over and put the printer on-line, since it was about done. [We left the
printer off-line when not actually in use because IBM charged us for service
based on how long each piece of peripheral equipment was on-line!!! No joke!]
This was actually quite useful, since you often didn't know until you had
run one of those things for a while whether it was going to run for only
ten minutes or for ten hours (or more)!!

After the speaker had been connected for a while, the machine room operators
discovered that they too could hear "how things were going", and know whether
it was safe to sneak down the hall to take a nap. In particular, if the card
reader went empty or something was ready to print and the operating system
started busy-waiting on the device, the speaker would let out a *loud* constant
"HOOONNNNNNK!" sound... which got 'em on their feet in a hurry (especially
since that particular sound penetrated up through the ceiling to the manager's
office, and if it went on too long he knew it meant somebody was goofing off!).


[*] Obligatory Lisp content: On a 1410, the "Zero Balance" light
came on whenever (zerop *most-recent-arithmetic-result-or-comparison*).

Rob Warnock, 8L-855
Applied Networking
Silicon Graphics, Inc.		Phone: 650-933-1673
2011 N. Shoreline Blvd.		FAX: 650-964-0811
Mountain View, CA  94043	PP-ASEL-IA