In message <3.0.1.16.19990316212916.3bef20fe(a)intellistar.net>et>, Joe writes:
 At 10:50 PM 3/16/99 -0000, you wrote:
 
They're made for the old 3M DC-1000 tapes, DEC tapes work great. 
No, I've tried DECtapes.  It takes a lot of force to get them into the
slot, and they don't seem to work.  :-)
For the uninitiated, DECtapes are six-inch reels of 3/4 inch (?) tape.
I think Joe is saying that the 85 needs the same cartridge tapes as the DEC
TU58 "DECtape II" drive, as commonly found on the PDP-11/44, VAX-11/750, and
other early-80s DEC machines.  Despite the moniker, there is almost 
 nothing in
 common between DECtape and DECtape II. 
  You may be right about the DEC stuff but the tapes that I have (about 20
of them) only say DECtape and they definitely fit the 9815, 9825, 9915, 85,
etc. 
A couple of points:
On the almost nothing they have in common...  Physically, they
don't, and they don't really have much in common in terms of the
tracks on the tape.  But they've got a unique feature in common.
They are used in a way that are block addressable, like a disk.
In fact Thompson's first UNIX on the PDP-7 used the original
DECtape as it's primary storage.
On the use of DECtape IIs for the HP-85 and 9800 series...  Please
don't.  As much as I love my HPs, I desperately keep any DECtape IIs
I have for use with DEC stuff.  The DECtape IIs are formatted at
the factory and I know of no way to format them with controllers
in the field.  (I'd love to be proved wrong about that, BTW.)  So
I (and I'm sure others) would be grateful if DECtape IIs could be
saved for use with TU-58s.
Brian L. Stuart