[COFF] Re: [TUHS] Re: reading historic magnetic tapes

[COFF] Re: [TUHS] Re: reading historic magnetic tapes

[Michael Kjörling]

On 28 Jan 2023 11:29 -0800, from frew@ucsb.edu (James Frew):
> As I was leaving the lab late one evening during this mini-crisis, I had to
> walk around a custodian who was busy giving the linoleum floor in the
> hallway its annual deep cleaning / polishing. This involved a dingus with a
> large (~18" diameter) horizontal buffing wheel, atop which sat an enormous
> (like, a cylinder about as big around as a soccer ball) electric motor,
> sparking commutator clearly visible through the vents in the metal housing.

This is probably more COFF than TUHS, but I recall a story from almost
certainly much later where someone (I think it was a secretary; for
now, let's pretend it was) had been told to change backup tapes daily
and set the freshly taken backup aside for safekeeping. Then one day
the storage failed and the backups were needed, only it turned out
when trying to restore the backups that _every_ _single_ _tape_ was
blank. Nobody, least of all the secretary, could explain how that
could have happened, and eventually, the secretary was asked to
demonstrate exactly what had been done every day. Turned out that
while getting the replacement tape, the secretary put the freshly
taken backup tape on a UPS, which apparently generated a strong
magnetic field, before setting that tape aside. So the freshly taken
backup tape was dutifully well and thoroughly erased. Nobody had
mentioned the little detail of not putting the tape near the UPS.

Oops.

-- 
Michael Kjörling                     🏡 https://michael.kjorling.se
“Remember when, on the Internet, nobody cared that you were a dog?”

[COFF] Re: reading historic magnetic tapes

[Charles H Sauer (he/him)]

This seems COFF, not TUHS, and mostly not digital...

I have many 4mm DAT cartridges from 20-30 years ago. Every now and then 
I will access one. So far I've yet to see evidence of the media degrading.

On 1/28/2023 4:12 AM, Steve Simon wrote:
> baking old, badly stored magnetic tapes prior to reading them is a common practice.

For the last year+ I have been digitizing selected audio tapes made in 
the 70s at AWHQ 
(https://en.wikipedia.org/wiki/Armadillo_World_Headquarters). The ones 
I've been working with are 1/4" on 10.5" reels. A printed inventory I 
was given says "bake" next to almost all of the items, but so far, after 
processing roughly 40 reels, I've yet to find one that seemed to need 
"baking" (actually, "baking" is a bit overstated, in that best practice 
is to raise temperature to roughly 150F -- 
https://www.radioworld.com/industry/baking-magnetic-recording-tape).

For now, I'm not able to share those AWHQ recordings, but I can share 
other recordings I made in the 60s and 70s at 
https://technologists.com/60sN70s/. In all those reels, many of which 
are cheap, unbranded tape, I didn't find any that seemed to me to need 
baking.

Charlie
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