On 01/04/2015 04:58, Johnny Billquist wrote:
On 2015-04-01 05:26, Christopher Parish wrote:
> Thanks for your help everyone. I finally figured out what was
> happening. Something is wrong with my (everyone's?) drives.
> In the process, I have confirmed that sometimes
the drive does
> mis-seek when making larger jumps across the pack. A single follow up
> seek is almost always enough.
This sounds strange. Are you sure you are not just
fiddling with the
head here? A head switch will taste like a seek, but it might actually
not move you as you would expect...
It does sound strange. As I mentioned a couple of days ago, I've been
ministering to an RL02 that occasionally had problems on the outer
tracks (possibly elsewhere but I never noticed that). Copying packs and
almost all seek/read/write worked fine but a very few operations didn't.
All the voltage, alignment and timing tests in the technical manual
checked out except for jitter running the oscillating seek tests (access
time checks) - especially for longer seeks. To cut a long story short,
there was a fault in the drive's DLM. Replacing it removed the jitter
and the drive now behaves perfectly.