3 Jan
2005
3 Jan
'05
11:46 a.m.
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(a)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