On Fri, Nov 12, 2010 at 6:09 PM, Pontus Pihlgren <pontus at update.uu.se> wrote:
Hi
Speakin of making punch cards and paper tape. What would it take to make
DECtape?
A roll of adhesive tape and rust?
/P
I remembered a comment on a list from some time past that 3M could
still make it if we ordered enough. I found the post on the archive of
alt.sys.pdp8. It is short on information, and probably apocryphal, but
the original questioner is of interest.
A posting to alt.sys.pdp8 from November, 1998:
From article <y4I%1.2614$zu2.2... at
news13.ispnews.com>,
by "Jay West"
Does anyone have some spare media for TU56 dectape?
Yes. I have perhaps a hundred reels of "Astrotape", an OEM version of
DECtape. One reel has been tested by Cam Farnell in Glenburnie, ON; he
has a working LAB 8/E with DECtape drive, and he said that it was written
in a strange (Astrotape, no doubt) format, but that after formatting as
a standard PDP-8 tape, it checked out as good. I haven't got any of my
own drives working yet.
Or, does anyone know if this can be ordered from
somewhere still today?
No, it can't be had, unless we can get a large group together to make a
bulk order. 3M once said that they could make new DECtape anytime someone
wanted to order in sufficiently large quantities, but we're talking in terms
of big quantities, enough to justify a production run.
One noteworthy thing about DECtape: It's double-faced sandwich
construction. That is, there is plastic on both sides of the oxide layer.
As a result, the oxide layer isn't exposed to air, where the binder can
oxidize and let it flake off. Old DECtapes should therefore, be very useful
except when they've been damaged by reading on poorly adjusted tape drives.
The usual mechanism of DECtape failure is wrinkling due to poorly adjusted
guides on the tape drive. Typically, the front edge gets stretched and
wrinkled, and when it is wrinkled enough, the tape won't stay in alignment
through the drive.
Doug Jones