Re: [AV Media Matters] CD-R vs. R-DAT

[rohre@ARLUT.UTEXAS.EDU]

As another branch of the University of Texas, I too must weigh in and
echo
Jim's comments. I am mortified that one of the students walked away from
a
course with the impression she expressed, as it is wrong. I hope I can
find
out who the misinformed instructor is; in fact, I was not aware of the
course the young lady mentioned, but then my research facility if remote
from the main campus where the course was held.

Most small format media transports with tape are incorporating on board
cleaning wheels to remove any debris in the vicinity of the heads,
before
the heads can clog.

In addition, the harder magnetic materials are more resistant to the
multiple passes of the tape over the heads, and in fact some media
vendors
are offering 30 year lifetime claims.  Of course, the fact of small
format
back ups, is that few are ever reused enough to reach the 30 year wear.
The
trend has been for another back up format to appear and cause computer
backup practice to migrate to more dense or more robust media.

That  being said, there have been initial problems with at least 3 media
types I have seen in the past ten years.  I would not pick something for
an
archive, until it has achieved a level of support and reliability in the
community.  And that too, is a problem, with widely varying tastes in
media
formats with such a wide variety available. Offshore vendors are more
guarded in admitting to problems it seems, or perhaps there was a
smaller
community of vendors and users when earlier recording formats were
manufactured in the United States.

There was a discussion at one  point that an archival copy had to mirror
the
original.  If that were the case in all instances, it would not be
possible
to recopy wax cylinders as archival grade machines for that never
existed.
At some point, you have to migrate to backing up on a supportable, (even
error correcting) modern media, and trust the error correction to not
conceal anything you wanted in the original.

And even before a copy session, THOROUGHLY checking out the copy medium
and
transport to verify its correct operation.  This can only be done with
proper test media, and a trial copy that is fully inspected before being
declared a true copy of the original.  And of course, the original media
must be preserved in good environment, until an even better copy format
and
media become available.

Stuart M. Rohre
Applied Research Labs, Univ. of TX.

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