23 Jan
2022
23 Jan
'22
5:40 p.m.
From: Gary Oliver
I've always thought the physical tape wound on a
DECtape spool was a
fairly conventional 'sandwich' of mylar/oxide/mylar ...
Was there some kind of 'lubricating' coat on the data side? It makes
sense, but none of my DEC documents or Googling has any mention of
lubrication ...
If someone has some detail information on the tape construction, I'd am
curious to see it.
Dunno if you know of this:
http://www.bitsavers.org/pdf/dec/dectape/3M_DECtape_Spec_Nov66.pdf
but it doesn't mention any lubrication, just a "Protective Overlay" layer,
over the "Coating" (which I assume is the oxide). I'm a bit surprised that
"some of the data side of the tape came off on the wipe", though, unless the
"various concentrations of isopropanol/water" dissolved the Protective
Overlay.
Noel