Magnetic belt format

[Adrian Tuddenham]

Anyone recognise this?

http://www.flickr.com/photos/nigelbewley/sets/72157621325859180/

--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

 

[William Sommerwerck]

It might be this...

http://www-03.ibm.com/ibm/history/exhibits/vintage/vintage_4506VV4019.html

 

[Jeff Liebermann]

On Wed, 15 Jul 2009 17:34:46 +0100,
adrian@poppyrecords.invalid.invalid (Adrian Tuddenham) wrote:

Anyone recognise this?
http://www.flickr.com/photos/nigelbewley/sets/72157621325859180/

Possibly an IBM dictation machine belt:
<http://www.soundsaver.com/dictationbelts.htm>
These guys sound like they're in the business of transcribbling old
tapes. They might be more helpful than my guessing.


--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[Adrian Tuddenham]

William Sommerwerck <grizzledgeezer@comcast.net> wrote:

It might be this...

http://www-03.ibm.com/ibm/history/exhibits/vintage/vintage_4506VV4019.html

Similar - but there are some significant differences. The mystery belt
has only a single hole in the edge and there appears to be a splice in
it (which suggests to me that it was made up from readily-available tape
stock by a firm who could not afford to have a special loop format made
just for their system).

--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

 

[Meat Plow]

On Wed, 15 Jul 2009 17:34:46 +0100,
adrian@poppyrecords.invalid.invalid (Adrian Tuddenham)wrote:

Anyone recognise this?

http://www.flickr.com/photos/nigelbewley/sets/72157621325859180/

Hmmmm, nothing like it in the history of recording media I'm familiar
with and that covers a broad area. I don't see a need to record
anything on that but for maybe voice on a portable device. Given its
size and endless loop configuration I can envision an audio head
traveling across the width while its running. But recording to reels
of tape or wire has been around for 75 years or so.

Could be out of some scientific data recording device that would be
left outdoors in a location to record meteorological/geological data.

I don't recognize what it is but I do recognize what it isn't if that
makes sense.

 

[Meat Plow]

On Wed, 15 Jul 2009 09:50:46 -0700, "William Sommerwerck"
<grizzledgeezer@comcast.net>wrote:

It might be this...

http://www-03.ibm.com/ibm/history/exhibits/vintage/vintage_4506VV4019.html

I would say you're closer than 'in the ballpark'.

 

[Nicholas Bodley]

On Wed, 15 Jul 2009 17:34:46 +0100, Adrian Tuddenham wrote:

Anyone recognise this?

http://www.flickr.com/photos/nigelbewley/sets/72157621325859180/

Sorry, I can't help much. Seems that there would be a dropout as the
splice went past the head. If it's for data recording, then the index
hole would most likely make the recording wait until the splice had gone
past the head.

You might well want to see the tracks on the belt. The popular green
magnetic viewing film is much too insensitive and has poor resolution
compared to other devices and methods.

Of course, once you see the tracks, then you need to figure out what to
do with them! That's when the real fun begins.

There used to be (late 1960s, early to maybe mid 1970s) preparations of
fine gray magnetic powder in a volatile carrier liquid. You'd shake the
container to undo settling, pour some into a little "dish", and dunk
audio tape into the liquid. It took a bit of technique, but you'd see the
recorded pattern. You'd surely want to clean off the tape afterwards!

Beware of such a preparation that contained iron carbonyl; that's
poisonous. Almost certain that what I used was not toxic.

3m made a curious magnetic viewer of that variety, which was re-usable.
It had a suspension of fine brown particles in a closed container.

Eventually, Arnold Magnetics took over the distribution and maybe
manufacture.

Both the consumable-suspension and Arnold viewer have quite-good
resolution and sensitivity.

I must stress that if this is like the one I once owned, it's critically
important to treat the bond between the Al foil on the bottom and the
plastic body with uncommon care. It's not fragile, but don't drop it.
Amazing to think, but even 3M apparently couldn't come up with a
satisfactory adhesive that didn't have to be stored wet! That jar with
its wet sponge is essential. I'm thinking of buying one; I'll put it into
another snap-lid plastic food-storage container with a bit of water, just
to be doubly-safe.

Color photo:
<https://www.arnoldmagnetics.com/v2/sales/Product.aspx?id=238>
Link to PDF that includes info on other things as well as the viewer:
<https://www.arnoldmagnetics.com/v2/sales/pdf/B-1022.pdf>

When I called a few years ago, they asked $88 (US).

I trusted the cover gasket on my jar, and it let the water vapor escape
over some months of disuse. The dry viewer's adhesive bond was
heartbreakingly fragile, and the fluid evaporated in seconds. In a phone
call to Arnold a few years ago, they said that their covers are much
better. I'm still going to put mine inside another container.

This type of viewer is also available from a Swedish company, iirc for
approx. $330 US, iirc! They also have a rectangular version with larger
area, at some rather scary price.

Indeed, I'd say that depending upon the value of the data, one would want
to consider whether building a reader would be worth the effort.

The Arnold viewer should also show the stripes on plastic cards such as
credit cards, and probably floppy discs removed from their housings or
jackets.

I'm fairly sure that the Bell System electromechanical phone central
offices used seamless rubber belts with magnetic content for analog[ue]
voice playback; afaik, the playback head moved to the appropriate track.
Voice content was brief messages to the caller.

Conceivable that this belt was used for such a purpose, and that no
individual track had enough content to reach the splice. In that event,
the belt drive would return it to home position, sensing the hole.

Consider also similar announcing systems for the likes of air terminals
and railroad stations.

This could/should be fun!

P.S. : I looked at some other Google hits, and found this:
<http://tig.colorist.org/pipermail/tig/2006-January/008792.html>
(Note the scrambled spelling. )

I know of Richard Hess, and he knows quite a lot about his business.

"Kyread Magnetic Tape Developer" -- was about 1/5 as costly, but in a
spray can.

My Google search string was
[arnold Magnetics 1022 magnetic viewer]

HTH!

--
Nicabod =+= Waltham, Mass.
In future decades, will deciphering digital media become
a branch of cryptanalysis?

 

[Nicholas Bodley]

On Wed, 15 Jul 2009 17:34:46 +0100, Adrian Tuddenham wrote:

Anyone recognise this?

http://www.flickr.com/photos/nigelbewley/sets/72157621325859180/

At the moment, I'd say that it's best not to firmly assume that the
recorded info. is necessarily a long helix, so to speak.

However (as I just remembered) brief audio dropouts are not particularly
noticeable (see "last-resort" muting in CD playback for coping with
corrupted data). I looked more carefully at the photos, and noticed that
the splice looks like a butt joint (with a small gap) tape-spliced on
the inside.

(Btw, flickr's software has a bug -- it shows only two of the four images
from the fancy scrolling selector)

If it has many short tracks and has a homing scheme such as I described
in my previous message, the tracks would very likely have visible ends,
I'd think. In such a case, they would be parallel to the edge.

I did notice an offer to build a reader. If that's done, the mechanism
has to be precise (rollers very close to theoretical cylinders,
scrupulously parallel; probably gentle flange on one to keep the belt
centered. I don't like the idea of guides, which could easily damage the
edges.

instead of making a precision mechanism, perhaps adapt a good-quality
unloved inkjet printer for moving the playback head. The print head
probably has a nice fine-resolution stepping drive, and perhaps even
microstepping to interpolate between steps. It also is likely to have a
relatively fine-pitch optical linear encoder (taut plastic strip with
fine transverse black lines). As well, the mechanical guides are likely
to be quite good -- straightness, repeatability, consistence of position,
etc. The gap between print nozzles and paper has to be quite small to get
good resolution, and that's not maintained by a servo.

For instance, in an HP DJ(?) 672C, the printhead carrier guide rod must
have very tight straightness specs; likewise, the guide rods in an
optical (CD/DVD) drive. (As well, spindle runout in a modern HD must be
exceedingly small, and the bearings for the head actuator must be really
good.)

Of course, the steps are going to be of the wrong size, so if the printer
doesn't do microstepping, try to set up a microstepping driver instead of
using what's in the printer.

For me, trying to use any of the existing electronics in the printer
(other than the power supply) seems formidably difficult, but I'm fairly
confident that there are people who know how.

A courteous query to Richard Hess might be very helpful. He's the kind of
guy, imho, who might have a quad-head VTR in very good condition, read to
run.

Just remembered:
<http://en.wikipedia.org/wiki/Dead_Media_Project>
Google on [dead media project] for more. Somebody who was on that list
must know exactly what those belts are!

I would welcome e-mail about matters of interest concerning these, but
please don't feel obliged. (Please remove the lowered dashes
("underscores")).

Again, HTH!

--
Nicabod =+= Waltham, Mass.
who worked for Sony video tape div. when all of it was open reel
and consumer decks had sliprings

 

[Adrian Tuddenham]

Nicholas Bodley <n_bod_ley@speakeasy.net> wrote:

On Wed, 15 Jul 2009 17:34:46 +0100, Adrian Tuddenham wrote:

Anyone recognise this?

http://www.flickr.com/photos/nigelbewley/sets/72157621325859180/

Sorry, I can't help much. Seems that there would be a dropout as the
splice went past the head. If it's for data recording, then the index
hole would most likely make the recording wait until the splice had gone
past the head.

There are many interesting points in both your posts. I don't know if
the recording was actually in the form of one long helix or whether it
comprised separate tracks, each starting just after the splice. Perhaps
the documentation with the belt suggests how it was meant to be
recorded, but I don't yet have access to it.

The hole could be there to ensure that the belt begins playing
individual messages just after the splice; but splice looks to me as
though it might be diagonal, which would knock that theory on the head.

You might well want to see the tracks on the belt. The popular green
magnetic viewing film is much too insensitive and has poor resolution
compared to other devices and methods.
[...]

I had wondered about obtaining a viewer, so thanks for all the info. If
the tracks are audio, it would be a simple matter to rig up a transport
system and hold a tape head against it by hand just as a first check on
how the tracks are arranged.

I have offered to construct a playback machine, but a lot will depend on
the economics of the project. If there are dozens of these belts with
valuable archives recorded on them, tha cost can be justified; but if
there is only one belt with a recording of no particular historic
interest, I doubt if it will be worthwhile.

Previous project:
<http://www.poppyrecords.co.uk/other/recordgraph/recordgraph.htm>

--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

 

[Nicholas Bodley]

On Sun, 19 Jul 2009 18:41:01 +0100, Adrian Tuddenham wrote:

Previous project:
http://www.poppyrecords.co.uk/other/recordgraph/recordgraph.htm

Very impressive! (As well, an interesting "Dead Medium")

I apologise for being somewhat dismissive in my commentary.

Your work reminds me of a two talented free-lancers I know. One made
Vickers hardness-tester diamond indenters, and repaired Rockwell
indenters.

The other made a crystal (or just a boule?) puller for synthetic sapphire.

--
Nicabod =+= Waltham, Mass.

 

[Adrian Tuddenham]

Nicholas Bodley <n_bod_ley@speakeasy.net> wrote:

On Sun, 19 Jul 2009 18:41:01 +0100, Adrian Tuddenham wrote:

Previous project:
http://www.poppyrecords.co.uk/other/recordgraph/recordgraph.htm

Very impressive! (As well, an interesting "Dead Medium")

It came at an 'interesting time' in world affairs, so I would have
expected a lot of valuable historic recordings would start turning up in
that format - but so far only the von Manstein trial has been discovered
on this side of the pond.

I apologise for being somewhat dismissive in my commentary.

Your comments were most welcome - especially the possibility that the
recordings might have been individual announcement tracks which each
started from the splice. Nobody else had thought of that.

I have now obtained a littel more information on the belts, including
the fact that the splice is slightly skewed, so it seems to be only one
long track.

Your work reminds me of a two talented free-lancers I know. One made
Vickers hardness-tester diamond indenters, and repaired Rockwell
indenters.

The other made a crystal (or just a boule?) puller for synthetic sapphire.

Those projects sound as though they might be more profitable than my
line of business. I must find something to make that rich people
need....

--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk