Re: Put a heater in the safe then ?
Ah yes... Apple ][ 5 1/4in drives.
Woz had the genius idea of saving 5c on the cost of each drive by deleting the track zero sensor. To ensure that the heads were positioned at track 0 prior to boot up, the computer would smash the heads against the track 0 stop 39 times. That is the source of the awful “brraaaack!” sound characteristic of these drives at power on.
This feature / abuse provided Apple service centres with a regular income stream; customers had to present their drives to have radial alignments performed at regular intervals.