RL02K Pack Reliability/Characteristics

[Chris Elmquist]

Is an unmodified RL02 drive involved in this process or have you somehow
modified a drive and attached the USB interface to the guts?

In an unmodified drive, you can adjust the read gain (it's part of the
tuneup/calibration process) and I found that after doing this adjustment
and even increasing the gain slightly beyond what the spec called out,
I was able to turn suspect or unreliable packs to reliable ones.

I think you can encounter varying read levels from the packs as a function
of the drives they were written on and maybe even degradation in signal
level over time.  A slight "tweak" to your read gain can make up for this,
that is, if you still have the read amplifier circuit in the drive :-)

Chris

On Monday (03/30/2015 at 08:43AM -0700), Lyle Bickley wrote:
> On Mon, 30 Mar 2015 05:47:26 +0000
> Christopher Parish <christopher.parish at parishcomputers.com> wrote:
> 
> > I've gotten my RL-02 -> USB Mass Storage controller mostly working
> > with a few residual gremlins.  Specifically, I've noticed from my
> > testing that I have good packs, ones that read out almost the same
> > every time, and bad packs, ones where half the bits seem to be in
> > different states every time I read them.  I've left write support
> > untested until I can solve this problem.
> > 
> > Right now, my working theory is that different controllers had
> > slightly different timing characteristics, and I may need to adjust
> > more of my DPLL parameters dynamically to deal with that (something
> > I'd rather avoid).  Of course, most of these packs haven't been put
> > into a drive since the mid-80s, and there could be some bit rot going
> > on.
> > 
> > As many of you have much more experience dealing with these drives
> > than I do, my questions are:
> > 
> > - What type of long term reliability have people noticed from their
> > RL02K packs?1
> 
> I've found the reliability of RL01s and RL02s to be excellent. I have
> (3) RL02's drives I use regularly with about (30) different cartridges.
> Over the years I have rarely had problems reading/writing packs between
> drives.
> 
> > - Is garbage data sometimes normal for certain packs until they are
> > rewritten with “fresh” data?
> 
> I have had packs on rare occasions which when I first obtained them had
> a few records which were unreadable - and a clean reformat made them
> 100% error free. After doing so, the packs will run reliably for years.
> 
> > - Has anyone noticed pack compatibility problems between various
> > computers/RL-02 controllers?
> 
> No.
> 
> Regards,
> Lyle
> -- 
> Bickley Consulting West Inc.
> http://bickleywest.com
> 
> "Black holes are where God is dividing by zero"

-- 
Chris Elmquist