Reviving old hard drives

[Dwight K. Elvey]

Hi
 All I can say is that those were the words from the
actual engineers that were working on the problem.
Yes, I do believe the disk had coatings but they
were dry lub ( like Teflon ) and none flowing.
Anything that would flow would quickly destroy the disk.
Any lump on the surface would cause the head to bounce.
Anything that flowed slowly would cause a lump.
Since this doesn't happen, it couldn't be. A smoke
particle is a lump. Dust is usually so large that
the head knocks it out of the way.
 Still, they said they solved the problem by making
the surface a little less smooth.
 If someone opened a disk and saw lube on the surface,
that disk had a failed bearing seal.
Dwight
 
>From: "Brad Parker" <brad at heeltoe.com>
>
>
>"Joe R." wrote:
>...
>>slide (or rotate) just as easily. I've looked at a couple of drive platters
>>that had sticktion problems and there definitely seems to be wax or
>>something holding the heads to the platters.
>
>I think almost all 3 1/2" drive media has some sort of coating on it.
>What it is varies over time and mfg.  I remember that most of it had
>'lubrication like' properties - it's been a long time however and I may
>be slightly off.
>
>I seem to recall the magnetic coating was sputtered on and then another
>coating was put on top.  As I remember sometimes the top coating would
>pool around the heads after they landed.
>
>but it's all a dim memory and my memories are probably very dated these
>days since the density has gone up by factor of 1000.
>
>I do remember walking through Tony Lapine's labs and watching watching
>drives running inside laminar flow hoods :-)  head balistics where the
>order of the day and made for some interesting firmware.
>
>-brad
>