Reviving old hard drives

"Joe R." wrote: ... 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