On 06/17/2015 11:56 AM, Johnny Billquist wrote:
On 2015-06-17 18:36, Pontus Pihlgren wrote:
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.
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
