[Info-vax] DLT Tape degaussing services

[Tom Linden]

On Fri, 20 Mar 2009 07:55:51 -0700, Rich Jordan <jordan at ccs4vms.com> wrote:

> On Mar 19, 9:32 pm, "Richard B. Gilbert" <rgilber... at comcast.net>
> wrote:
>> Rich Jordan wrote:
>> > On Mar 19, 2:02 pm, "John Smith \(not the one @ HP\)"
>> > <a... at nonymous.com> wrote:
>> >> "David Mathog" <mat... at caltech.edu> wrote in message
>>
>> >>news:gpopc4$8gi$1 at naig.caltech.edu...
>>
>> >>>> I'm certainly
>> >>>> willing to try a smaller unit (missed one on ebay yesterday that  
>> was
>> >>>> for reel to reel audio tapes) but expect it won't be overly
>> >>>> effective.  So far no luck at locating a nearby service.
>> >>> See what's available at the local Universities and research labs.  
>>  NMR
>> >>> machines and cyclotrons have enormous magnets.  How far are you  
>> from Fermi
>> >>> lab?
>> >>> Regards,
>> >>> David Mathog
>> >> How about the nearest Navy Yard when they degauss their ships? Put  
>> the tapes
>> >> in plastic bags and hang them over the side as the ship is  
>> degaussed. Ought
>> >> to work.
>>
>> > Heh.  Unfortunately I doubt the Navy does anything like that here in
>> > Ill Annoy.  I actually did look around to see if there was a wrecking
>> > yard that used a crane with an electromagnet but couldn't find one
>> > (and if I did I doubt they'd be willing, but who knows).
>>
>> > I knew someone at Fermi but he left.  Without that contact I'd hate to
>> > bother them for something like this.  Fun thought though...
>>
>> > Maybe I should build a railgun... if it didn't erase them it could
>> > launch them pretty hard; more fun than a sledgehammer for data
>> > destruction.
>>
>> > I did some more digging and there seems to be a breakpoint at about
>> > 3500-3700 Gauss where the sellers start claiming the ability to erase
>> > DLT cartridges (and around 4350 Gauss for SDLT-2 and higher.  I read
>> > reports that the Radio Shack high power unit was not able to do the
>> > job on DLTTape IV 20GB cartridges (ironically the same situation;
>> > someone trying to make tapes used on a real DLT drive usable on a
>> > VS80).
>>
>> > Found one service that may end up costing about $4.00/cartridge by the
>> > time shipping there and back is considered, and nothing local so far.
>> > I can get new tapes on Ebay for very close to that price... I think
>> > we're going to end up doing the crush kill destroy thing on the
>> > tapes.  A shame, but its not worth the time and effort to get them
>> > wiped.
>>
>> > Rich
>>
>> Is there some reason you can't simply INIT the tapes and reuse them?
>
> Yep.  They were used on a DLT8000 drive.  The potential target has a
> VS80 drive, which uses a different means of recording (apparently).
> The VS80 will not allow a tape that has been used on a DLT8000 to even
> remain loaded; it ejects it unconditionally.  No possibility of
> performing an INIT.  A brand new tape, or one that has been properly
> degaussed/erased, can be used in either drive according to the manual,
> but once a tape is used in a DLT8000 it becomes unusable in a VS80.
>
> Its strictly an economy thing for us.  The tapes, which are nearly
> new, need to be retasked or destroyed.  Retasking outside of our
> office would require erasing (and we don't have a compatible drive to
> re-use them as-is) in any case.  Erasing would coincidentally make
> them usable at the VS80 customer site who desperately needs more tapes
> but doesn't have the budget for it right now (and we'd be heroes ;).
>
> If we can't erase them they get sledgehammered.
>
> Rich

I think this might work
http://www.magnet4sale.com/product.php?productid=16896&cat=249&page=1
$105

-- 
PL/I for OpenVMS
www.kednos.com