In a message dated 11/8/2001 6:44:58 AM Central Standard Time,
foo_at_siconic.com writes:
> On Wed, 7 Nov 2001, Richard Erlacher wrote:
>
> > The mechanism taken by itself may have been reliable enough, BUT,
> > since there was no track-zero sensor, (I think that's the reason) the
> > "recal" operation rams the head assembly into the outside stops
> > multiple times each time it is performed, and that's going to harm the
> > mechanism. Do that enough times and the system loses alignment, which
> > makes it prone to failure. As the drive changes in radial alignment,
> > the data written with it becomes "off-track" so it will be difficult
> > to read when the drive is realigned or when the diskette is put in a
> > properly aligned drive. The consequences of poor alignment is not an
> > Apple problem, though the Apple way of using the drives causes
> > misalignment more quickly than with drives that sense when track zero
> > has been reached.
>
> I never had problems as you describe, nor have I ever heard of anyone
> needing to adjust the alignment of an Apple disk drive.
>
> As far as I know, there is no procedure in the Disk ][ manual for aligning
> a drive, and as far as I know, there is no reason for needing one.
>
> Sellam
I would think that the only time an alignment would be required is when disks
written from one drive will not work in another drive assuming the rotation
speed is the same.
I did need to have a drive aligned once in 1987 or so when for some reason,
both the drive AND the controller card went bad. Not knowing any better, I
tried all my dos3.3 floppies, which hosed the boot track, rendering them
unusable. Never have fixed those disks yet. probably are still readable too.
Somewhere in my extensive stash of apple goodies, I do have some genuine
alignment disks but are useless to anyone unless you have an ocilloscope
hooked up and know what you are doing. Anyone can adjust the rotation speed,
however. I still say the disk ][ was the best disk subsystem around. fast(er)
and reliable and decent storage I think at 143k.
clearing the HYPE about bioterrorism
www.formatc.org/terrorism.htm
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Received on Thu Nov 08 2001 - 08:36:33 GMT