Drive Alignment (was: Multiple Topics...)

From: Tony Duell <ard_at_odin.phy.bris.ac.uk>
Date: Wed Aug 20 03:24:38 1997

> At 05:55 AM 8/19/97 +0000, you wrote:
> > drive alignment for various disk drives (not even close to ready yet).
>
> Something to mention is to make copies of disks created on drives you plan
> to realign before realigning them. That is, if drive A is out of alignment
> and disk A was created on Drive A, make a copy of disk A (in drive A) onto
> disk B in Drive B (where drive B is a known, well aligned drive.)

Absolutely... And then you find a disk 6 months later that was recorded on
the misaligned drive and for which you have no backup. Been there, done
that... :-(

This is the one time that the 'insert disk, move head to find points where
read amplitude falls off, set midway between them' method is useful. You
can often deliberately misalign a drive to read such a disk.

I've though about making a set of drives (at leat 8" and 5.25") with
calibrated head offset devices (probably micrometers linked to the stepper
chassis). Then I can tweak them a little more easily to read defective
disks.

 
> Otherwise, when you get all your drives working fine, you won't be able to
> read any of the disks created when they were out of whack.

> Uncle Roger "There is pleasure pure in being mad

-tony
Received on Wed Aug 20 1997 - 03:24:38 BST