🚀 go-pugleaf

[POSTED TO comp.sys.ibm.pc.hardware.storage]

This reference is apparently to a very old technology for coating disk
surfaces with magnetic material called "spin coating" which did result in
uneven coating thickness.  However, current coating technologies do not use
a spinning disk, so there is no variation in coating thickness.


Steven <steven.vandenbosch@alcatel.be> wrote:

>Ok, I've got the book here : It's "PC onderhoud en uitbreiding" from "EC".  It's a
>translation from a german book from "Data Becker", but doesn't state the original title.
>
>In chapter 9 - The hard disk : speed ain't no magic word - on paige 472 and 473 it states :
>
>
>Klemmende koppen
>
>Met name bij oudere schijven, die al lang gebruikt worden, treedt een probleem op.  Door de
>centrifugaalkracht wordt de laag op de plaat langzaam naar buiten geslingerd.  De plaat wordt
>daardoor aan de rand dikker dan bij het midden.  Helaas wordt de kop hier meestal geplaatst
>bij het parkeren en kan deze vast komen te zitten!  U kunt dit herkennen, doordat de
>schijfmotor bromt en de plaat probeert op toeren te komen - zonder succes.  Als eerste en
>eenmalige oplossing moet u in dit geval de harde schijf demonteren en er zijwaarts een tik op
>geven, om de kop los te maken.  Als bij inschakelen de harde schijf wel op toeren komt, maakt
>u onmiddellijk een back-up van alle belangrijke bestanden en koopt u direct een nieuwe harde
>schijf!
>
>
>In english this would be:
>Jamming heads
>Especially with older disks, that are already used over a longer period of time, a problem
>occurs.  Because of the centrifugal force the layer on the disk is slowly forced outward.  In
>that way the disk becomes thicker by the edges than in the middle.  Unfortunately is this the
>place where the head is placed during parking and can get stuck!  You can identify this
>problem, because the diskmotor is humming and the disk is trying to spin up - to no avail.
>As a first and final solution you have to disassemble the harddisk en give it a tick on it's
>side, to free the head.  If the disk spins up when powered on, you instantly make a backup of
>all important files and you immediatly buy a new hard disk!
>
>
>
>Never the less, I've calculated the speed of the outer tracks of a 10000! rpm disk and it was
>so low that I really don't think anymore that this is really possible (also the layer being
>only microns thick).  Even more, I've opened up an XT-harddisk of 40MB (bigfoot) and the
>heads are parked on the inner tracks.  I will open up another disk and see where this one
>parks.  If this one also parks on the inside I will send a mail to the publisher (EC) to ask
>where they got their information.
>
>regards
>Steven
>
>John Navas wrote:
>
>> [POSTED TO comp.sys.ibm.pc.hardware.storage]
>> Wacko-Jacko <steven.vandenbosch@alcatel.be> wrote:
>>
>> >The book is over at a friends place now.  I will get it during the week-end and include
>> >the text both in dutch and in english (about the movement of particles).
>>
>> I waiting impatiently.  ;-)
>>
>> >About the
>> >magnetism getting lost, I suggest something about (electro)magnetism.  There are quite a
>> >few engineers here at alcatel, and those I interviewed just now (it's getting late and
>> >most people have gone home) all agree.
>>
>> Unfortunately, they are badly misinformed.  But then Alcatel is not a disk
>> drive manf.  ;-)
>>
>> >I'll be back...
>> >
>> >after the week-end
>>
>> I waiting impatiently.
>>
>> >John Navas wrote:
>> >
>> >> [POSTED TO comp.sys.ibm.pc.hardware.storage]
>> >> Wacko-Jacko <steven.vandenbosch@alcatel.be> wrote:
>> >>
>> >> >Guess you didn't know either that you should low level format your harddrive every
>> >> >five years because the magnetic information gets lost in time and by just copying,
>> >> >you don't take along the formating information.
>> >>
>> >> With all due respect, that is utter nonsense.
>> >>
>> >> >Just read up about harddisks, you just might learn something.  I would recommend a
>> >> >good one about various hardware but it is in dutch and I don't suppose that is well
>> >> >known in Australia.
>> >>
>> >> I've worked in the hard disk industry on and off for over 20 years.  How
>> >> about you?
>> >
>> >I've worked in the nuclear sector for quite some time, doesn't make me an expert though.
>>
>> I've testified as an expert in a number disk technology lawsuits.
>>
>> >> p.s.  If you think you have any sort of proof for your claims, please be
>> >> more specific with what we should be reading.
>>
>> --
>> Best regards,
>> John  mailto:Usenet@NavasGrp.Dublin.CA.US  http://www.aimnet.com/~jnavas/

-- 
Best regards,
John  mailto:Usenet@NavasGrp.Dublin.CA.US  http://www.aimnet.com/~jnavas/