9 Oct
2024
9 Oct
'24
12:52 p.m.
Tom,
If you would like some known good disks to test with, I'd be glad to format
a few 8 inch disks for you to use as test disks. Just email me and we can
figure it out. Chuck sent me a few disks when I was first setting up my 8
inch drives a few years back and that was invaluable. I'd be glad to pass
along the favor.
Travis
On Wed, Oct 9, 2024 at 1:38 PM Wayne S via cctalk <cctalk(a)classiccmp.org>
wrote:
Tom, make sure to clean the heads of the floppy drive
and check the heads
to see if they don’t have any sharp edges, from excessive wear, that could
damage the disk. Also spin it up with a scratch disk to see if it spins
okay.
Check the source disk for mold and dirt and see if it spins smoothly in
the jacket w/o hangup.
Sent from my iPhone
On Oct 9, 2024, at 12:05, Tom Stepleton via
cctalk <
cctalk(a)classiccmp.org> wrote:
Hi folks,
I have a floppy disk data archiving project to undertake, and although
I'm
aware that this can sometimes lead to spirited
discussion (and hope to
avoid that!), I'm interested in current good practices for pulling data
off
of hard-to-replace disks.
In this situation, the disks are 8" floppies likely in ordinary IBM
26-sector, 77-track, 128-bytes/sector, double-sided FM format. I have a
flux reader and will have a pair of Shugart 851 drives for the job; these
likely haven't been used for a while, though. At this stage I'll consider
the job done if I manage to get good low-level recordings from the disks:
assuming the FM data decodes well and sector CRCs look good, further
analysis can come later.
The main risk I'm worried about is physical damage to the media. While
reportedly the disks don't show visible defects (nb: they belong to
someone
else so I can't inspect them myself right
now), I'm still anxious about
any
chance I might find the binder that secures the
magnetic material to the
cookie degraded to the point of allowing the oxide to come free. Most
other
situations I think I can deal with, but I'd
like to have a more concrete
plan if I start to find oxide building up on the heads.
I'd be interested to know what precautions people might take for common
data recovery problems. One option is cyclomethicone for cleaning and
lubrication if necessary, but other than "you could use this", I'd be
interested to know details of how people put it to use if they are
worried
about media failure. Meanwhile, I'm
disinclined to use isopropanol or
other
more aggressive solvents given received wisdom,
although I know opinions
differ here.
The disks are boot media and other materials relating to the RSRE Flex
operating system <https://en.wikipedia.org/wiki/Flex_machine> as
developed
for PERQ workstations. I'm not aware of other
copies of this OS being
available, though it would relieve some of the pressure to learn that
these
weren't the only ones. The disks themselves
are primarily ICL-branded
although a few indicate manufacture or resale by Maxell, DEC, Inmac,
among
other brands.
Is there anything else that people would advise me to look out for?
I did find this thread
<https://classiccmp.org/pipermail/cctalk/2018-July/040673.html>, but
practices may have advanced in the past six years. I know the whiteboard
cleaner that folks seem to have liked is difficult to find these days,
particularly here in Britain. I've also had a hard time finding Photo Flo
or similar photographic wetting agents and have used deionised water
with a
drop of dish soap instead.
Thanks for any advice,
--T