Msg: 6069 *Conference*

10-16-95 09:39:55

From: RON WIESEN

To : PAUL WHITING

Subj: REPLY TO MSG #6066 (IS MY PDD2 DYING?!)

I'm not familiar with Tandy drives.  Disk drives generally have one or more
threshold cyclinders (same as track number for 1-platter drives) where the
electronics of the head read/write circuits switches for greater density.  The
magnetic density gets progressively greater as heads are moved toward the
center (away from the edge) of the media. So when a "threshold cyclinder" is
crossed, the read/write circuits receive a signal so that they may "compensate"
for the new density.
 
Perhaps Tandy drives have a threshold track and if so then your drive's
symptoms indicate that the threshold signal is active, but the read/write
compensation is not engaging or is not effective.
 
Just my thoughts here.  I'm no Tandy drive expert.