Re: Classic 5 1/4 Disk Grinding Sound -- Why?

[David Wilson <david@uow.edu.au>]

Lyrical Nanoha <LyricalNanoha@dosius.net> writes:
>The beige ones do that too.  So does the disk ][, but not as loud. 
>They're the same thing at different speeds actually - since the drive has 
>no way of telling the system it's at head zero the system is forced to ram 
>the head against the wall to make sure it's at head zero.

It has to step outwards 40 tracks to ensure that the head is located at
TRACK zero. This was a cost saving measure on the part of Apple when they
designed the Disk ][ analog card. A few extra gates and a track zero optical
sensor would have been worth it in my opinion :-).

I have a 3rd party (Multitech) slimline direct drive Apple Disk ][ compatible
drive which does have a track zero sensor which disables the stepper motor
when it reaches track zero. Silence is bliss. Before I got that drive I would
park my drives on track 39 before I powered the computer off. When I turned
it on the next day the slot 6 boot code would step outwards 40 tracks
and the head would be on track zero without a loud noise.
-- 
David Wilson  School of IT & CS, Uni of Wollongong, Australia