[comp.sys.sgi] Best 8mm tapes?

jdt@voodoo.UUCP (Jim Tomlinson) (06/28/90)

Hope this hasn't been discussed.  We just got a 4D/320S (gloat, gloat) 
with the 8mm cartridge drive.  The question is, which manufacturer makes
the best tape for digital use?  Please e-mail; I'll summarize and post.
Thanx. - jdt

-- 
Jim Tomlinson             P.O.Box 24346   \
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baskett%forest.asd@SGI.COM (06/30/90)

People tell me that the top-of-the-line Sony tapes that are
approximately $10 and usually sold out at your local video store are
best.  Cheap 8mm video tape is supposed to be dangerous for your data.

Forest Baskett
Silicon Graphics

jim@baroque.Stanford.EDU (James Helman) (06/30/90)

Does anyone know if using the top quality tapes completely saves you
from the write-through problem?  The problem (myth?) as I understand
it is that over time (> 1 year) the magnetic pattern written on one
section tape can affect the next layer with which it is in contact.
I've heard that some manufacturers advise you to rerun the tape every
year just to change the way it's wound on the reel.  Otherwise it's
data decay time.  Since we keep many tapes for 5 or more years, we've
been too paranoid to buy an 8mm drive, although others here seem quite
happy with theirs.

If top quality tapes don't guarantee long term data storage, will SGI
or a third-party have a DAT subsystem out soon?  I understand they
are much better in this regard.

Jim Helman
Department of Applied Physics			6 Trillium Lane
Stanford University				San Carlos, CA 94070
(jim@thrush.stanford.edu) 			(415) 723-9127

msc@ramoth.esd.sgi.com (Mark Callow) (06/30/90)

In article <JIM.90Jun29141926@baroque.Stanford.EDU>,
jim@baroque.Stanford.EDU (James Helman) writes:
|> If top quality tapes don't guarantee long term data storage, will SGI
|> or a third-party have a DAT subsystem out soon?  I understand they
|> are much better in this regard.
|> 
Recent articles in rec.video indicate that DAT will not perform any better
than 8mm video tape with regard to tape stretching, data longevity etc.
Once article mentioned that because DAT's contain digital data with 2 levels
of error detection and correction the effects of stretched tape will be
reduced.  However when using 8mm video for backup the data is digital...
--
From the TARDIS of Mark Callow
msc@ramoth.sgi.com, ...{ames,decwrl}!sgi!msc
"There is much virtue in a window.  It is to a human being as a frame is to
a painting, as a proscenium to a play.  It strongly defines its content."

karsh@trifolium.esd.sgi.com (Bruce Karsh) (06/30/90)

In article <JIM.90Jun29141926@baroque.Stanford.EDU> jim@baroque.Stanford.EDU (James Helman) writes:
>Does anyone know if using the top quality tapes completely saves you
>from the write-through problem?  The problem (myth?) as I understand
>it is that over time (> 1 year) the magnetic pattern written on one
>section tape can affect the next layer with which it is in contact.
>I've heard that some manufacturers advise you to rerun the tape every
>year just to change the way it's wound on the reel.  Otherwise it's
>data decay time.  Since we keep many tapes for 5 or more years, we've
>been too paranoid to buy an 8mm drive, although others here seem quite
>happy with theirs.

Print-thru on tapes is an old problem.  I've seen advice to re-run
old-fashioned 1/2 inch tapes periodically too.  However, hardly anybody
does this and the tapes seem to work for years without it.  It might be
a good idea though if you are archiving data "for eternity".  I have
seen very old 1/2 inch (1600 bpi) tapes which had accumulated read errors
over time.

I don't know whether 8mm is any better or worse than 1/2 inch tape.

>If top quality tapes don't guarantee long term data storage, will SGI
>or a third-party have a DAT subsystem out soon?  I understand they
>are much better in this regard.

Computer DAT tapes have 3 layers of error correcting codes.  The audio
DAT tapes only have 2.  Since consumer music tapes will soon be competing
with CDs and cassettes, they'll have to be adequate media to allow the
audio tapes to last for years.  If that's the case, then the extra
layer of ECC should ensure that computer data will also last for years.


			Bruce Karsh
			karsh@sgi.com

schuman@sgi.com (Aaron Schuman) (07/03/90)

Forest Baskett>	People tell me that the top-of-the-line Sony tapes 
Forest Baskett>	that are approximately $10 and usually sold out at
Forest Baskett>	your local video store are best.

I got Sony tapes for about $6.00 at Price Club,
and they work fine for backup.  If anybody knows
of a cheaper source, please post.

tonia@maddog.sgi.com (Tonia Cantrell) (07/07/90)

I've been using the Sony P6-120MP for backups for a couple
of years now and so far I've had no problems.  I've been
buying them lately at Fry's Electronics for $5.99 each.