17 Jun
2015
17 Jun
'15
8:02 p.m.
On 06/17/2015 11:56 AM, Johnny Billquist wrote:
On 2015-06-17 18:36, Pontus Pihlgren wrote:
These pack formatters used air bearings to give the most vibration-free
rotation of the spindle.
They were generally pretty open units, not like disk drives, and were
run in clean rooms by people wearing low-dust overalls.
Jon
How was alignment packs produced?
As far as I know, in special machines mounted on slabs on stone
weighting tons, standing on dampeners, so that you had absolutely
vibration free environment, and then a very precisely controlled head
control system that could write the tracks at the exact place they
should be. I think the alingment packs even have some tracks
intentionally offset from true center in order to check signal
strength when heads are slightly off track as well.