From owner-freebsd-hardware Mon Oct 14 21:19:53 1996 Return-Path: owner-hardware Received: (from root@localhost) by freefall.freebsd.org (8.7.5/8.7.3) id VAA24376 for hardware-outgoing; Mon, 14 Oct 1996 21:19:53 -0700 (PDT) Received: from genesis.atrad.adelaide.edu.au (genesis.atrad.adelaide.edu.au [129.127.96.120]) by freefall.freebsd.org (8.7.5/8.7.3) with ESMTP id VAA24370 for ; Mon, 14 Oct 1996 21:19:47 -0700 (PDT) Received: from msmith@localhost by genesis.atrad.adelaide.edu.au (8.6.12/8.6.9) id NAA18931; Tue, 15 Oct 1996 13:49:15 +0930 From: Michael Smith Message-Id: <199610150419.NAA18931@genesis.atrad.adelaide.edu.au> Subject: Re: sticky drives (was: your mail) To: dbabler@Rigel.orionsys.com (Dave Babler) Date: Tue, 15 Oct 1996 13:49:14 +0930 (CST) Cc: rgrimes@GndRsh.aac.dev.com, freebsd-hardware@freebsd.org In-Reply-To: from "Dave Babler" at Oct 14, 96 03:34:48 pm MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-hardware@freebsd.org X-Loop: FreeBSD.org Precedence: bulk Dave Babler stands accused of saying: > > This is absolutely true, dropping a drive below 0 deg C is a sure fire > > way to damage it. Even the non-operating temp spec on almost all mfg's > > disk is +5 C on the lower end. Having done MIL-SPEC drive work that > > had to operate over -55 to +125 C the actual hardest part of this range > > was the -5 to +5 C range, condensation being a real killer. > > Isn't the chamber where the platters reside hermetically sealed? If so, > how would moisture be there to condense in the first place? Firstly; no, the chamber is often not sealed. If you pull a drive apart you will often notice that there's a breather port with a bit of filter material stuck over it. Many drives will have some silica gel in them as well to help keep the humidity down. Secondly, the drives are usually assembled in rooms with some nominal amount of air humidity, so that even if the unit were sealed, there would still be moisture inside. > -Dave -- ]] Mike Smith, Software Engineer msmith@atrad.adelaide.edu.au [[ ]] Genesis Software genesis@atrad.adelaide.edu.au [[ ]] High-speed data acquisition and (GSM mobile) 0411-222-496 [[ ]] realtime instrument control (ph/fax) +61-8-267-3039 [[ ]] Collector of old Unix hardware. "Where are your PEZ?" The Tick [[