On 08/08/2016 07:31 PM, Eric Smith wrote:
  I'm seeing more errors on low numbered tracks, so
I really think I
 just need a better data separator algorithm. 
That's surprising--low-numbered tracks should be the easiest to read.
At the expense of sounding like a complete idiot, have you checked the
alignment of the drive?   It's not uncommon to get a batch of disks
written with alignment slightly off (blame whomever you  want).  I keep
an "unaligned" drive around to tweak when I run into those cases.
--Chuck