RL02K Pack Reliability/Characteristics

[Pete Turnbull]

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.

-- 
Pete

Pete Turnbull