> On Jan 26, 2022, at 1:28 PM, Tom Gardner via cctalk
> wrote:
>
> ...The UNISERVO I, of Univac I, tape drives had a separate spool of clear
> very thin film that was clock motor wound across the head when tape was
> moving, since the phosphor bronze plated tape was very abrasive. That
> exi
> On Jan 24, 2022, at 10:27 PM, Gary Oliver via cctech
wrote:
>
>> ...
>
> As to the real reason I was doing this: Most of my tapes are un-boxed and
have suffered being in a dusty area (before I got them) with the dust
forming a sort of 'crust' on the outside of the tape. It's only on the
fir
On 1/25/22 14:06, Gary Oliver via cctalk wrote:
> My search results were dominated (even with 'advanced search') by Amazon
> and Ebay (naturally) but also by a couple of vendors (Cricut as example)
> and I never found anything coming up for .10 inch or equivalent in mm.
> This appears to be .10 i
On 1/25/22 12:24 PM, Chuck Guzis via cctalk wrote:
On 1/25/22 06:18, Paul Koning via cctalk wrote:
On Jan 24, 2022, at 10:27 PM, Gary Oliver via cctech
wrote:
...
As to the real reason I was doing this: Most of my tapes are un-boxed and have suffered
being in a dusty area (before I got t
On 1/25/22 06:18, Paul Koning via cctalk wrote:
>
>
>> On Jan 24, 2022, at 10:27 PM, Gary Oliver via cctech
>> wrote:
>>
>>> ...
>>
>> As to the real reason I was doing this: Most of my tapes are un-boxed and
>> have suffered being in a dusty area (before I got them) with the dust
>> forming
> On Jan 25, 2022, at 3:13 PM, Bjoren Davis via cctalk
> wrote:
>
>
> On 1/25/2022 9:18 AM, Paul Koning via cctalk wrote:
>>
>>> On Jan 24, 2022, at 10:27 PM, Gary Oliver via cctech
>>> wrote:
>>>
...
>>>
>>> BTW, does anyone know of a source for these vinyl strips. My old ones ar
On 1/25/2022 9:18 AM, Paul Koning via cctalk wrote:
On Jan 24, 2022, at 10:27 PM, Gary Oliver via cctech
wrote:
...
As to the real reason I was doing this: Most of my tapes are un-boxed and have suffered
being in a dusty area (before I got them) with the dust forming a sort of 'crust' o
> On Jan 24, 2022, at 10:27 PM, Gary Oliver via cctech
> wrote:
>
>> ...
>
> As to the real reason I was doing this: Most of my tapes are un-boxed and
> have suffered being in a dusty area (before I got them) with the dust forming
> a sort of 'crust' on the outside of the tape. It's only
> On Jan 25, 2022, at 1:13 AM, Chuck Guzis via cctalk
> wrote:
>
> So, can we assume that the words about a "tape sandwich" refer to a
> mylar base, oxide coating, and a lubricant/protective coating?
>
> That is not an oxide coating sandwiched between to layers of mylar.
The 3M spec for the
On 1/24/22 4:25 PM, David Gesswein via cctech wrote:
On Sun, Jan 23, 2022 at 03:09:53PM -0800, Gary Oliver wrote:
Taking the bits of tape, I exposed them to various concentrations of
isopropanol/water (from about 25% to 99% iso) and found than in all cases,
some of the data side of the tape cam
On Sun, Jan 23, 2022 at 03:09:53PM -0800, Gary Oliver wrote:
> Taking the bits of tape, I exposed them to various concentrations of
> isopropanol/water (from about 25% to 99% iso) and found than in all cases,
> some of the data side of the tape came off on the wipe.? The remaining tape
> fragment
So, can we assume that the words about a "tape sandwich" refer to a
mylar base, oxide coating, and a lubricant/protective coating?
That is not an oxide coating sandwiched between to layers of mylar.
There was such a tape construction, used on the Datamatic 1000. (ca. 1955)
--Chuck
On 1/24/22 12:42 PM, Noel Chiappa via cctalk wrote:
> From: Gary Oliver
> Paul - thanks for the bitsavers reference.
Ahem!
In any case, it's Al who really deserves the credit, for finding that document,
and
putting it up.
Noel
Clearly Al is to blame :-) Yes, thanks to al
On 1/24/22 11:09 AM, Chris Zach via cctalk wrote:
It sounds more like some sort of sprayed-on coating of some sort of
abrasion-resistent material. It might well be porous, which would be
a possible explanation for the oxide coming off when rubbed with solvent.
paul
Is it possible we're
On 1/24/22 11:50, Paul Koning wrote:
>
> I thought Black Watch has coating on the back, as others mentioned. DECtape
> is not black but brown, so graphite doesn't seem to be involved.
I grabbed a reel of BW out of my stash and you're correct--the black is
on the back.
Still, I can see where a
> From: Gary Oliver
> Paul - thanks for the bitsavers reference.
Ahem!
In any case, it's Al who really deserves the credit, for finding that document,
and
putting it up.
Noel
> On Jan 24, 2022, at 2:46 PM, Chuck Guzis via cctalk
> wrote:
>
> On 1/24/22 11:05, Paul Koning via cctalk wrote:
>
>> Looking at that spec some items pop out.
>>
>> The coating is quite thin, much thinner than the backing. Not too
>> surprising actually, if it were thick it would reduce
On 1/24/22 11:05, Paul Koning via cctalk wrote:
> Looking at that spec some items pop out.
>
> The coating is quite thin, much thinner than the backing. Not too surprising
> actually, if it were thick it would reduce the max possible bit density.
>
> There is a coating wear spec (as a ratio of
The other thing on my mind is, high end audio tape from the same period had a
coating to reduce static electricity. But that would be on the rear side.
> On 24 Jan 2022, at 20:09, Chris Zach via cctalk wrote:
>
> It sounds more like some sort of sprayed-on coating of some sort of
> abrasion-re
It sounds more like some sort of sprayed-on coating of some sort of
abrasion-resistent material. It might well be porous, which would be a
possible explanation for the oxide coming off when rubbed with solvent.
paul
Is it possible we're looking at something called "dirt"?
C
> On Jan 23, 2022, at 8:40 PM, Noel Chiappa via cctalk
> wrote:
>
>> 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
>>
On 1/24/22 7:30 AM, Paul Koning via cctalk wrote:
On Jan 23, 2022, at 8:40 PM, Noel Chiappa via cctalk
wrote:
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' coa
> On Jan 24, 2022, at 10:56 AM, Jon Elson via cctalk
> wrote:
>
> Back in 1971 or so, we had a PDP-5 with DECTapes, and bought 3/4" analog
> recorder tapes surplus to make up new tapes. It was much thinner than
> DECTape, and we had print-through issues of tapes that were stored for a few
Back in 1971 or so, we had a PDP-5 with DECTapes, and bought
3/4" analog recorder tapes surplus to make up new tapes. It
was much thinner than DECTape, and we had print-through
issues of tapes that were stored for a few weeks. That
seemed to clear up if the tapes were then used again. I
gues
One way to tell is to do an independent test. I have a ton of Dectape,
including some stuff that is probably psychological data from 50 years ago.
So what are the exact steps, I'll replicate on some LincTapes and report
back.
C
On 1/24/2022 10:30 AM, Paul Koning via cctalk wrote:
On Jan
> On Jan 23, 2022, at 8:40 PM, Noel Chiappa via cctalk
> wrote:
>
>> 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
> 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
27 matches
Mail list logo
