Rotating memory data recovery

[Paul Koning]

>>>>> "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