[TUHS] reading historic magnetic tapes

[TUHS] reading historic magnetic tapes

[Steve Simon]

i worked for some years on video and film archive restoration.

baking old, badly stored magnetic tapes prior to reading them is a common practice.

my favourite was a story of a rock band (i think the stones) who wanted to play an old 24 track master tape but discovered it seemed to be stuck together.

there is a nasty affliction of mag tapes called sticky vinegar syndrome, so they did the right thing and sent a section of tape for analysis.

the results came back: the tape had suffered impregnation with “vodka and coke”.

some things never change.

-Steve

[TUHS] Re: reading historic magnetic tapes

[James Frew]

My "favorite" magtape story:

In a former life I managed a university research lab whose main activity 
was analyzing digital imagery from Earth satellites, back when said 
imagery was distributed and locally archived on 9-track magtape. Most of 
the OGs on this list will recall that the standard way of storing said 
magtapes was on floor-to-ceiling racks that held the tapes by a hook on 
the plastic ring (the "seal")  around the edge of the tape.

The story begins with a bunch of read errors showing up on some of the 
tapes. We quickly pinned it down to a specific sensor and range of 
dates, which of course led to a back-and-forth with NASA that didn't 
converge (other researchers were having no problems with identical data 
on tapes from the same batch, etc.)

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. I asked the custodian if he'd done the floors in our 
lab recently. "Sure, they did them last week" (on the graveyard shift, 
apparently, since nobody noticed.) Hmm. Back into the lab, and there 
were the offending tapes, all occupying the bottom row of the tape rack, 
right next to an extra-shiny linoleum floor. Indeed, the floor 
*underneath* the tapes was mostly polished---the helpful custodian 
apparently ran the motor right up against the hanging tapes, to get the 
buffer as far under as possible...

Filed under "threats you never ever considered."

/Frew

[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?”