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From: jamesa@dadla.UUCP (James Akiyama)
Newsgroups: net.micro.pc
Subject: Re: My new AT disk trouble theory
Message-ID: <238@dadla.UUCP>
Date: Mon, 29-Apr-85 18:20:56 EDT
Article-I.D.: dadla.238
Posted: Mon Apr 29 18:20:56 1985
Date-Received: Wed, 1-May-85 03:37:49 EDT
References: <38700003@ima.UUCP>
Organization: Tektronix, Beaverton OR
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> 
> Well, our nine PC ATs are sicker than ever.  One has developed an 
> unpleasant discophagic tendency, in that any hard disk drive you 
> put in it soon looks pretty bad.  
> 
> I have a new theory -- it's the temperature.  The regional service manager
> from our computer store (Businessland) came by and reported that their
> customers in Florida have been banging on their ATs like crazy and have no
> trouble.  So it occurs to me, CMI makes their disks in Chatsworth CA, where
> it's pretty warm, or in Singapore, where it's warmer.  Then they ship them
> to Boca Raton, where it's equally temperate, they work fine there, and then
> ship 'em out.  We open them up in Boston, where the weather is not in the
> least temperate, and they fail.  If this theory is true, we should have better
> luck this summer than we did during the winter.  I sure hope so.
> 
> In the meantime, I'd appreciate short notes from AT users reporting on how
> your disks are and how the weather's been.
> 
> John Levine, Javelin Software, Cambridge MA 617-494-1400
> { decvax!cca | think | ihnp4 | cbosgd }!ima!johnl, Levine@YALE.ARPA

Several months ago I also suspected that the AT disk problems may be temperature
related.  I suspected that the problem may be related to different temperature
expansion coefficients between the fixed disk head structure and the media.  So
I started digging around for a temperature specification from IBM.  In IBM's
Hardware Announcements for the IBM AT (publication HA-36, August 1984) the
following Technical Data for the system unit is listed:

	Air Temperature:
		-System on  60 to  90 degrees F (15.6-32.2 degrees C)
		-System off 50 to 110 degrees F (10-43 degrees C)

Although I find these numbers rather hard to believe, IBM has so far not
denied them (at least as far as I know).  Could it be that AT's were designed
to sit in air conditioned offices?