Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cwjcc!neoucom!wtm
From: wtm@neoucom.UUCP (Bill Mayhew)
Newsgroups: comp.sys.ibm.pc
Subject: Re: High pitched whine in DEL System 200
Summary: My IBM model 80 does that
Message-ID: <1700@neoucom.UUCP>
Date: 11 Aug 89 14:34:46 GMT
References: <6958@cloud9.Stratus.COM>
Organization: Northeastern Ohio Universities College of Medicine
Lines: 21


I have an old 16 MHZ version model 80.  When the model 80 is
sitting in the msdos idle task, the 386 chip itself emits about a
12 KHz squeal.  The noise got worse when I installed an 80387
coprocessor.  About a year ago, there was an article in Infoworld
about 80386s emitting various squeals.  I took the cover off the
machine and listened carefully, and it was quite obvious that the
sound was coming from the CPU chip and not the power supply or the
surrounding  circuitry.  Depending on what's going on, the 386
emits various obnoxious chirps or buzzes while executing
application programs too.  Running Xenix 2.2.2 also causes the
system to emit various shrill sounds.

Oh yes, I unplugged the winchester drive while conducting my
listening tests, so the noise wasn't coming from there either.

(A 486 system must be *very* loud.  I guess they don't call it a
screamer for nothing! :-) )


Bill