Browse Prior Art Database

Peak Detect Channel Delta V Switch Point Optimization During Manufacturing

IP.com Disclosure Number: IPCOM000122749D
Original Publication Date: 1991-Dec-01
Included in the Prior Art Database: 2005-Apr-04
Document File: 1 page(s) / 51K

Publishing Venue

IBM

Related People

Bergquist, MA: AUTHOR

Abstract

A method to increase the capability for the Peak Detect Channel to handle a wider range of heads and disk combinations is disclosed. The ID delta V switch point cylinder would be optimized for each drive in manufacturing during self-test. The cylinder value would be stored on the drive for each head; no hardware changes would be required.

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Peak Detect Channel Delta V Switch Point Optimization During Manufacturing

      A method to increase the capability for the Peak Detect Channel
to handle a wider range of heads and disk combinations is disclosed.
The ID delta V switch point cylinder would be optimized for each
drive in manufacturing during self-test.  The cylinder value would be
stored on the drive for each head; no hardware changes would be
required.

      To enhance the capability of the present Peak Detect Channel to
handle the wider range of head and disk combinations a test could be
performed to optimize the cylinder at which the delta V switches to
the lower ID value.

      This test would be performed on each head in a file prior to
SAT.  The test would most likely be run in the burn-in racks without
hardware changes using "Griffy code".

      The test would consist of a short performance run at cylinder
500 (today's switch point + 50) using the OD delta V value.  If the
error rate was acceptable (better than 10**8), 50 cylinders would be
added and the test would be rerun until the unacceptable performance
cylinder was found. When the unacceptable point was found, the switch
point would be 50 cylinders less than that point for that head. If
the performance at cylinder 500 was unacceptable, a retest using the
ID delta V value would be run and if this was found to be acceptable,
cylinders would be subtracted in groups of 50 till performance was no
longer acceptable.  At this poi...