Path: utzoo!utgpu!news-server.csri.toronto.edu!bonnie.concordia.ca!uunet!lll-winken!taco!hobbes.catt.ncsu.edu!kdarling From: kdarling@hobbes.catt.ncsu.edu (Kevin Darling) Newsgroups: comp.sys.amiga.advocacy Subject: Re: The Amigas Future Message-ID: <1991Jun29.194949.26510@ncsu.edu> Date: 29 Jun 91 19:49:49 GMT References: <1991Jun21.183216.29240@news.iastate.edu> <88@ryptyde.UUCP> <17300@chopin.udel.edu> <1991Jun25.164959.16960@infonode.ingr.com> <1419@cbmger.UUCP> <9106281409.05@rmkhome.UUCP> Sender: news@ncsu.edu (USENET News System) Organization: North Carolina State University Lines: 37 rmk@rmkhome.UUCP (Rick Kelly) writes: >At on time, both Seagate and Quantum had "stiction" problems. This was >caused by a supplier of lubricants for the hard disk industry. They shipped >batches of solvent that was too viscous. The result was, that when you >powered down your hard disk, the heads would move to the landing zone and >get stuck. When you tried to spin up the drive, it would not be able to >retract the heads to track 0. Quantum solved the problem by changing their >rom code to increase the power curve on the head controller servo. At power >up it would simply yank the heads back harder than usual. I don't know what >Seagate used as a fix. I can add some information a friend sent to me back in Sept 1989: "I just remembered another thing.. the original ST-1xx drives WITH 3 PLATTERS such as the ST-138 and the ST-157R had a problem which Seagate called "sticktion" (or something like that... pronounced STICK-SHUN)." "I have spent literally hundreds of $$$ on calls to Seagate concerning both the sticking problem and the firmware revisions that we talked about the other day. The problem with stuck drives was condensation. Actually, it wasn't condensation like you see on a fogged up mirror, it was just a very thin (several molecules thick) layer of water. What happens is that a drive which is running circulates air through the filters. The drive circulates ambient air with a certain relative humidity. This air is warmed by the drive, but eventually the RH goes back up to what the ambient air has due to circulation. Then, when the drive is shut off, the air stops circulating and cools off. The RH goes up and water molecules condense on the platters. The heads and platters are so smooth and shiny that they just stick. Of course, they have already solved the problem and the current drives don't suffer from it." "Seagate engineers solved that problem with a different head stepper driver chip and different startup code which wiggles the heads to break them free upon startup." Whether or not the lubricant used had an effect on this problem, I don't know. Some say the lubricant story was made up. -