Using a TK50 tape on a TK70?

From: sms_at_antinode.org <(sms_at_antinode.org)>
Date: Wed Jul 21 18:38:22 1999

   From: allisonp_at_world.std.com (Allison J Parent)

> Ah, I believe TK50 and TK70 tape is different media (magnetics). That
> is why the TK70 can only read TK50 formats.

   The number of tracks is different, with more on the TK70 than on the
TK50 (not surprisingly). When a TK70 drive tries to read a TK50 tape,
it's easy enough to center a smaller (TK70) read head on a larger (TK50)
track. It is far more difficult (that is, practically impossible) for
the smaller write head to write a track which covers the larger track
well enough to satisfy the larger read head. _This_ is why a TK70 drive
can not write a tape which can be read by a TK50 drive.

   The magnetic properties of the tapes may or may not be different. My
experience suggests that they're close enough. (Of course, also I've
used HD floppies as DD by taping over the hole, again, with no
problems. Please, let's not start that discussion here.) Regardless,
it's the difference in track configuration which is the fundamental
source of the problem. The same argument applies similarly to QIC tape
drives of various densities.

   If anyone actually _knows_ about the magnetic properties of the two
types of tapes, I'd be pleased to learn of the differences, if any. I
could live happliy without additional uninformed speculation.

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Received on Wed Jul 21 1999 - 18:38:22 BST