28 Jan
2015
28 Jan
'15
4:18 p.m.
Alexandre Souza wrote:
----- Original Message ----- From: "Mark J.
Blair" <nf6x at nf6x.net>
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk at classiccmp.org>
Sent: Tuesday, January 27, 2015 3:04 PM
Subject: Destructive Imaging of DECTAPE II Media
[Snip]
What do you folks think about this silliness?
It has been over 2 years since I last used my TU58 tape drive,
but it was still working then with (of course USABLE) TU58
tapes, although a good percentage were no longer in that
category. If it seems reasonable, I can try to see if the TU58
tape drive will still function correctly.
If the TU58 tapes which need to be recovered can still be
read by a TU58 drive, then I could undertake to recover
those ones. Note that I am in Toronto, so postage would
be MUCH more than within the US.
Unfortunately, there is no visual difference between tapes
which can still be read and those which have errors that
can't be recovered. But if the tape can't even be moved
or the drive belt is broken, either of those problems would
prevent a standard DEC TU58 drive from being able to
recover any data from the tape.
Jerome Fine
28 Jan
28 Jan
4:37 p.m.
I found the older posts about band installation and about restoring stretched bands with
hot water. I do not recall, however, whether anybody has posted about successfully
unsticking the band from the tape media without stripping oxide. That's something
I'd sure like to know about!
--
Mark J. Blair, NF6X <nf6x at nf6x.net>
http://www.nf6x.net/
4:56 p.m.
On 1/28/15 8:37 AM, Mark J. Blair wrote:
I found the older posts about band installation and
about restoring stretched bands with hot water. I do not recall, however, whether anybody
has posted about successfully unsticking the band from the tape media without stripping
oxide. That's something I'd sure like to know about!
http://www.hp9845.net/9845/tutorials/savetapes/ has an interesting discussion of the
problems
of recovering DC-100 tapes but doesn't mention unsticking the tape. I'll keep
digging. I suspect
it will be wetting the band at the point of contact with the tape. I'm guessing the
safest way to
do this will be to cut the band and carefully lift the band and reels off of the hubs,
then lay the
tape out flat on a paper towel and wet the parts that are stuck to the binder.
Like they say on the 9845 page, recovering some of the data is better than nothing, since
there are
probably other copies somewhere with bad blocks in other places.
5:27 p.m.
On Jan 28, 2015, at 08:56, Al Kossow <aek at
bitsavers.org> wrote:
I'm guessing the safest way to
do this will be to cut the band and carefully lift the band and reels off of the hubs,
then lay the
tape out flat on a paper towel and wet the parts that are stuck to the binder.
I think it may be safer to wet the tape (assuming that works) without straightening it
first. It seems to me that straightening it could apply enough force along the tape axis
to pull off the oxide.
When I get a chance, I'll look through my smallish pile of TU58 tapes to see if I have
any other not-so-precious ones with stuck bands to try.
Unfortunately, I made the mistake of trying to boot my VAX from the most precious tapes
without any special preparation, so if any of those had stuck but not broken bands, then
those tapes have already shed oxide. Hopefully in a non-critical area of the tapes, but
Murphy suggests otherwise.
--
Mark J. Blair, NF6X <nf6x at nf6x.net>
http://www.nf6x.net/
29 Jan
29 Jan
9:56 a.m.
On Wed, 28 Jan 2015, Al Kossow wrote:
On 1/28/15 8:37 AM, Mark J. Blair wrote:
It's simple: heat.
I heat the belt with the radiation from a halogen lamp (or other light
bulb that emits enough heat). But I suppose that the first couple of
minutes of a tape baking session will also do it.
Christian
I found the older posts about band installation
and about restoring
stretched bands with hot water. I do not recall, however, whether anybody
has posted about successfully unsticking the band from the tape media
without stripping oxide. That's something I'd sure like to know about!
http://www.hp9845.net/9845/tutorials/savetapes/ has an interesting
discussion of the problems of recovering DC-100 tapes but doesn't
mention unsticking the tape. I'll keep digging. I suspect it will be
wetting the band at the point of contact with the tape. I'm guessing the
4:38 p.m.
On Jan 29, 2015, at 01:56, Christian Corti <cc at
informatik.uni-stuttgart.de> wrote:
It's simple: heat.
I heat the belt with the radiation from a halogen lamp (or other light bulb that emits
enough heat). But I suppose that the first couple of minutes of a tape baking session will
also do it.
Excellent! I guess I need to build a media oven one of these days.
--
Mark J. Blair, NF6X <nf6x at nf6x.net>
http://www.nf6x.net/
6:39 p.m.
On Jan 29, 2015, at 1:56 AM, Christian Corti <cc at informatik.uni-stuttgart.de>
wrote:
On Wed, 28 Jan 2015, Al Kossow wrote:
IME, at least with DC600 carts, I get consistently better results peeling the belt off
before baking, than trying to remove them afterward, just in terms of the sticky residue
it leaves and the quality of reads through that residue. I should mention that it always
leaves a mark, but I have yet to see the oxide pull completely off to make a transparent
spot. If you?re actually pulling oxide off, that?d be a different scenario.
ok
bear.
On 1/28/15 8:37 AM, Mark J. Blair wrote:
It's simple: heat.
I heat the belt with the radiation from a halogen lamp (or other light bulb that emits
enough heat). But I suppose that the first couple of minutes of a tape baking session will
also do it. I found the older posts about band installation
and about restoring stretched bands with hot water. I do not recall, however, whether
anybody has posted about successfully unsticking the band from the tape media without
stripping oxide. That's something I'd sure like to know about!
http://www.hp9845.net/9845/tutorials/savetapes/ has an interesting discussion of the
problems of recovering DC-100 tapes but doesn't mention unsticking the tape. I'll
keep digging. I suspect it will be wetting the band at the point of contact with the tape.
I'm guessing the
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aek＠bitsavers.org -
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