Rotating memory data recovery

From: Paul Koning <pkoning_at_equallogic.com>
Date: Thu Sep 16 15:13:40 2004

>>>>> "John" == John Foust <jfoust_at_threedee.com> writes:

 John> At 04:00 PM 9/15/2004, you wrote:
>> I do not consider myself a magnetic-media expert, but I've made a
>> number of (low-density) controllers and en/de-coding schemes, and
>> repaired others, and read a lot (in one ear out the other
>> probably).

 John> With platters, there are clean-room issues as well as very
 John> difficult alignnment issues - imagine how difficult it would be
 John> to re-align a read head with the concentric bands on a platter
 John> that may have been slightly misaligned from its original hub.

True for moving head disks, but possibly not for head per track
devices. For example, head alignment of a DEC RF11 (512 kbytes per
platter) was done by eyeball, lining up the heads with engraved
circles on a glass or plexiglass alignment platter.

   paul
Received on Thu Sep 16 2004 - 15:13:40 BST