30 Mar
2015
30 Mar
'15
9:07 a.m.
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:
--
Chris Elmquist
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"