I don't post here much but but give TNMOC some love folks ...

I was in the UK's National Museum of Computing (Bletchley Park)
yesterday, with a friend doing the guided tour. There was just 6 of us
in the tour - they could do with some more folks on that? Or just walk
around yourself.

https://www.tnmoc.org

Saw an interesting tape drive there, the tape was 35mm film stock as
used by the cinema industry, but instead of photographic emulsion the
full width tape coat was magnetic for 8 tracks of data. The drive itself
being a modified cinema transport - was much cheaper then than tape
drives from the computer industry.

--
Adrian C

On Wed, 24 Jan 2024, Adrian Caspersz wrote:

> I don't post here much but but give TNMOC some love folks ...
>
> I was in the UK's National Museum of Computing (Bletchley Park) yesterday,
> with a friend doing the guided tour. There was just 6 of us in the tour -
> they could do with some more folks on that? Or just walk around yourself.
>
> https://www.tnmoc.org
>
> Saw an interesting tape drive there, the tape was 35mm film stock as used by
> the cinema industry, but instead of photographic emulsion the full width tape
> coat was magnetic for 8 tracks of data. The drive itself being a modified
> cinema transport - was much cheaper then than tape drives from the computer
> industry.
>
>

Is it easy to get to from London? I might have to go to London for a
business trip in 2024, and since I love these types of museums maybe it
could be a good idea to extend my trip over the weekend to go for a visit!

Best regards,
Daniel

D <nospam@example.net> wrote:

> Daniel

On Wed, 24 Jan 2024 16:05:18 +0100, D wrote:

>
> On Wed, 24 Jan 2024, Adrian Caspersz wrote:
>
>> I don't post here much but but give TNMOC some love folks ...
>>
>> I was in the UK's National Museum of Computing (Bletchley Park)
>> yesterday, with a friend doing the guided tour. There was just 6 of us
>> in the tour - they could do with some more folks on that? Or just walk
>> around yourself.
>>
>> https://www.tnmoc.org
>>
>> Saw an interesting tape drive there, the tape was 35mm film stock as
>> used by the cinema industry, but instead of photographic emulsion the
>> full width tape coat was magnetic for 8 tracks of data. The drive
>> itself being a modified cinema transport - was much cheaper then than
>> tape drives from the computer industry.
>>
>>
>>
> Is it easy to get to from London? I might have to go to London for a
> business trip in 2024, and since I love these types of museums maybe it
> could be a good idea to extend my trip over the weekend to go for a
> visit!

Train from Euston, and it's very near the station. When they decided on
Bletchley Park in WWII, communications were key, especially getting 4,000
workers per shift in and out. It's literally across the road from the
station.

Be careful not to pay for Bletchley Park entry if you just want TNMoC, as
they are both on the site.

--
Using UNIX since v6 (1975)...

Use the BIG mirror service in the UK:
http://www.mirrorservice.org

On 2024-01-24, Adrian Caspersz <email@here.invalid> wrote:

> I don't post here much but but give TNMOC some love folks ...
>
> I was in the UK's National Museum of Computing (Bletchley Park)
> yesterday, with a friend doing the guided tour. There was just 6 of us
> in the tour - they could do with some more folks on that? Or just walk
> around yourself.
>
> https://www.tnmoc.org

Sounds like an interesting place. Too bad it's an ocean away...

> Saw an interesting tape drive there, the tape was 35mm film stock as
> used by the cinema industry, but instead of photographic emulsion the
> full width tape coat was magnetic for 8 tracks of data. The drive itself
> being a modified cinema transport - was much cheaper then than tape
> drives from the computer industry.

I once saw a vinyl album which claimed to have been mastered on
such stock.

--
/~\ Charlie Gibbs | The Internet is like a big city:
\ / <cgibbs@kltpzyxm.invalid> | it has plenty of bright lights and
X I'm really at ac.dekanfrus | excitement, but also dark alleys
/ \ if you read it the right way. | down which the unwary get mugged.

On Wed, 24 Jan 2024 15:13:02 +0000
snipeco.2@gmail.com (Sn!pe) wrote:

> D <nospam@example.net> wrote:
>
> > Daniel
>
I see the legs of a Sn!pe are very long, ideal for stalking.

--
Bah, and indeed Humbug.

On Wed, 24 Jan 2024, Bob Eager wrote:

> On Wed, 24 Jan 2024 16:05:18 +0100, D wrote:
>
>
>>
>> On Wed, 24 Jan 2024, Adrian Caspersz wrote:
>>
>>> I don't post here much but but give TNMOC some love folks ...
>>>
>>> I was in the UK's National Museum of Computing (Bletchley Park)
>>> yesterday, with a friend doing the guided tour. There was just 6 of us
>>> in the tour - they could do with some more folks on that? Or just walk
>>> around yourself.
>>>
>>> https://www.tnmoc.org
>>>
>>> Saw an interesting tape drive there, the tape was 35mm film stock as
>>> used by the cinema industry, but instead of photographic emulsion the
>>> full width tape coat was magnetic for 8 tracks of data. The drive
>>> itself being a modified cinema transport - was much cheaper then than
>>> tape drives from the computer industry.
>>>
>>>
>>>
>> Is it easy to get to from London? I might have to go to London for a
>> business trip in 2024, and since I love these types of museums maybe it
>> could be a good idea to extend my trip over the weekend to go for a
>> visit!
>
> Train from Euston, and it's very near the station. When they decided on
> Bletchley Park in WWII, communications were key, especially getting 4,000
> workers per shift in and out. It's literally across the road from the
> station.
>
> Be careful not to pay for Bletchley Park entry if you just want TNMoC, as
> they are both on the site.

Great! Euston I've passed through on my trips. Thank you very much for the
tip, I hope I'll get the chance some time this year! =)

Kerr-Mudd, John <admin@127.0.0.1> wrote:

> On Wed, 24 Jan 2024 15:13:02 +0000
> snipeco.2@gmail.com (Sn!pe) wrote:
>
> > D <nospam@example.net> wrote:
> >
> > > Daniel
>
> I see the legs of a Sn!pe are very long, ideal for stalking.

Hardly stalking, I've been here for years.

--
^Ï^. Sn!pe, PA, FIBS - Professional Crastinator

My pet rock Gordon just is.

On Thu, 25 Jan 2024, Sn!pe wrote:

> Kerr-Mudd, John <admin@127.0.0.1> wrote:
>
>> On Wed, 24 Jan 2024 15:13:02 +0000
>> snipeco.2@gmail.com (Sn!pe) wrote:
>>
>>> D <nospam@example.net> wrote:
>>>
>>>> Daniel
>>
>> I see the legs of a Sn!pe are very long, ideal for stalking.
>
> Hardly stalking, I've been here for years.
>
>

Great minds think alike, isn't that the saying? Or perhaps the usenet is
so small, that it comes down to us three? ;)

Best regards,
Daniel

On Thu, 25 Jan 2024 03:57:04 GMT, Charlie Gibbs <cgibbs@kltpzyxm.invalid> wrote:

>On 2024-01-24, Adrian Caspersz <email@here.invalid> wrote:
>
>> I don't post here much but but give TNMOC some love folks ...
>>
>> I was in the UK's National Museum of Computing (Bletchley Park)
>> yesterday, with a friend doing the guided tour. There was just 6 of us
>> in the tour - they could do with some more folks on that? Or just walk
>> around yourself.
>>
>> https://www.tnmoc.org
>
>Sounds like an interesting place. Too bad it's an ocean away...
>
>> Saw an interesting tape drive there, the tape was 35mm film stock as
>> used by the cinema industry, but instead of photographic emulsion the
>> full width tape coat was magnetic for 8 tracks of data. The drive itself
>> being a modified cinema transport - was much cheaper then than tape
>> drives from the computer industry.
>
>I once saw a vinyl album which claimed to have been mastered on
>such stock.

"roentgenizdat"

from soviet bootleg "vinyl" recordings duplicated (cut? pressed?) into used
X-ray film.

Thomas Prufer

On 2024-01-26, Thomas Prufer <prufer.public@mnet-online.de.invalid> wrote:

> On Thu, 25 Jan 2024 03:57:04 GMT, Charlie Gibbs <cgibbs@kltpzyxm.invalid>
> wrote:
>
>> On 2024-01-24, Adrian Caspersz <email@here.invalid> wrote:
>>
>>> Saw an interesting tape drive there, the tape was 35mm film stock as
>>> used by the cinema industry, but instead of photographic emulsion the
>>> full width tape coat was magnetic for 8 tracks of data. The drive itself
>>> being a modified cinema transport - was much cheaper then than tape
>>> drives from the computer industry.
>>
>> I once saw a vinyl album which claimed to have been mastered on
>> such stock.
>
> "roentgenizdat"
>
> from soviet bootleg "vinyl" recordings duplicated (cut? pressed?) into used
> X-ray film.

The recording I heard was of Virgil Fox playing the John Wanamaker organ
in Philadelphia. His rendition of "Pomp and Cirumstance" was thrilling.
A quick web search confirms the 35mm mastering.

--
/~\ Charlie Gibbs | The Internet is like a big city:
\ / <cgibbs@kltpzyxm.invalid> | it has plenty of bright lights and
X I'm really at ac.dekanfrus | excitement, but also dark alleys
/ \ if you read it the right way. | down which the unwary get mugged.

On Thu, 25 Jan 2024 03:57:04 GMT, Charlie Gibbs wrote:

>> Saw an interesting tape drive there, the tape was 35mm film stock as
>> used by the cinema industry, but instead of photographic emulsion the
>> full width tape coat was magnetic for 8 tracks of data. The drive
>> itself being a modified cinema transport - was much cheaper then than
>> tape drives from the computer industry.
>
> I once saw a vinyl album which claimed to have been mastered on such
> stock.

Did you point out that this was a digital format, and vinyl-lovers are
supposed to abhor digital?

On 2024-03-28, Lawrence D'Oliveiro <ldo@nz.invalid> wrote:

> On Thu, 25 Jan 2024 03:57:04 GMT, Charlie Gibbs wrote:
>
>>> Saw an interesting tape drive there, the tape was 35mm film stock as
>>> used by the cinema industry, but instead of photographic emulsion the
>>> full width tape coat was magnetic for 8 tracks of data. The drive
>>> itself being a modified cinema transport - was much cheaper then than
>>> tape drives from the computer industry.
>>
>> I once saw a vinyl album which claimed to have been mastered on such
>> stock.
>
> Did you point out that this was a digital format, and vinyl-lovers are
> supposed to abhor digital?

The recording on film was analog. The album I heard was of Virgil Fox
playing the John Wanamaker organ in Philadelphia, recorded in 1964.
Digital only entered the picture when the album was remastered to CD.

I always wondered whether there would be flutter from the sprocket
wheel engaging and disengaging from the holes in the film, but this
doesn't seem to have been a problem. The recording I heard had been
remastered from film to vinyl. It sounded wonderful.

A bit of web searching reveals all sorts of interesting things
about this technique.

--
/~\ Charlie Gibbs | The Internet is like a big city:
\ / <cgibbs@kltpzyxm.invalid> | it has plenty of bright lights and
X I'm really at ac.dekanfrus | excitement, but also dark alleys
/ \ if you read it the right way. | down which the unwary get mugged.

On 2024-03-29 01:05, Charlie Gibbs wrote:

....

> I always wondered whether there would be flutter from the sprocket
> wheel engaging and disengaging from the holes in the film, but this
> doesn't seem to have been a problem. The recording I heard had been
> remastered from film to vinyl. It sounded wonderful.

Consider that the sound on movies was analogic and used this movement,
and had no such issues.

--
Cheers, Carlos.

On Fri, 29 Mar 2024 03:14:13 +0100, Carlos E.R. wrote:

> Consider that the sound on movies was analogic and used this movement,
> and had no such issues.

That’s because the sound track was offset by a dozen or more frames from
the corresponding image to show at that time. This allowed a loop of film
to absorb the shock between the two separate movements.

On 2024-03-29 04:08, Lawrence D'Oliveiro wrote:
> On Fri, 29 Mar 2024 03:14:13 +0100, Carlos E.R. wrote:
>
>> Consider that the sound on movies was analogic and used this movement,
>> and had no such issues.
>
> That’s because the sound track was offset by a dozen or more frames from
> the corresponding image to show at that time. This allowed a loop of film
> to absorb the shock between the two separate movements.

I know that, I was a projectionist.

But we were talking of a different thing, possible noise from "flutter
from the sprocket wheel engaging and disengaging from the holes in the film"

--
Cheers, Carlos.

On Fri, 29 Mar 2024 13:42:00 +0100, "Carlos E.R."
<robin_listas@es.invalid> wrote:
>On 2024-03-29 04:08, Lawrence D'Oliveiro wrote:
>> On Fri, 29 Mar 2024 03:14:13 +0100, Carlos E.R. wrote:
>>
>>> Consider that the sound on movies was analogic and used this movement,
>>> and had no such issues.
>>
>> That’s because the sound track was offset by a dozen or more frames from
>> the corresponding image to show at that time. This allowed a loop of film
>> to absorb the shock between the two separate movements.
>
>I know that, I was a projectionist.
>
>But we were talking of a different thing, possible noise from "flutter
>from the sprocket wheel engaging and disengaging from the holes in the film"

The movies shown on the US navy destroyer i was statoned on had
flutter on some movies. The guy who maintained the projector would
make an adjustment and the flutter, most of the time, would go away.
--
Jim

On 2024-03-29 15:50, D.J. wrote:
> On Fri, 29 Mar 2024 13:42:00 +0100, "Carlos E.R."
> <robin_listas@es.invalid> wrote:
>> On 2024-03-29 04:08, Lawrence D'Oliveiro wrote:
>>> On Fri, 29 Mar 2024 03:14:13 +0100, Carlos E.R. wrote:
>>>
>>>> Consider that the sound on movies was analogic and used this movement,
>>>> and had no such issues.
>>>
>>> That’s because the sound track was offset by a dozen or more frames from
>>> the corresponding image to show at that time. This allowed a loop of film
>>> to absorb the shock between the two separate movements.
>>
>> I know that, I was a projectionist.
>>
>> But we were talking of a different thing, possible noise from "flutter
>>from the sprocket wheel engaging and disengaging from the holes in the film"
>
> The movies shown on the US navy destroyer i was statoned on had
> flutter on some movies. The guy who maintained the projector would
> make an adjustment and the flutter, most of the time, would go away.

Yes, that's a different thing, it is flutter on the video. I'd bet the
sound was ok all the time?

The holes on the sides of the film, when the film has seen a fair bit of
use, get enlarged. This causes the movement to not be smooth, in
particular as each frame is shown it does not match exactly the position
of other frames. You get flutter.

The film passes a tiny window through which the light of the lantern
shows. The film is pressed to the metal by metal "skids" on the sides,
with adjustable pressure. The projectionist tries to use the smaller
pressure possible to reduce wear. When there is flutter, he increases
the pressure.

Here, a photo from wikipedia showing the mechanism:

https://en.wikipedia.org/wiki/Movie_projector#/media/File:Projmech.jpg

What I called skids, in the photo is called "gate pressure plate", and
the tiny window is the "aperture mask" (my first language is not
English, I used different names). There is a "pressure plate tension
knob" in the photo.

--
Cheers, Carlos.

On Sun, 31 Mar 2024 16:13:04 +0200, "Carlos E.R."
<robin_listas@es.invalid> wrote:
>On 2024-03-29 15:50, D.J. wrote:
>> On Fri, 29 Mar 2024 13:42:00 +0100, "Carlos E.R."
>> <robin_listas@es.invalid> wrote:
>>> On 2024-03-29 04:08, Lawrence D'Oliveiro wrote:
>>>> On Fri, 29 Mar 2024 03:14:13 +0100, Carlos E.R. wrote:
>>>>
>>>>> Consider that the sound on movies was analogic and used this movement,
>>>>> and had no such issues.
>>>>
>>>> That’s because the sound track was offset by a dozen or more frames from
>>>> the corresponding image to show at that time. This allowed a loop of film
>>>> to absorb the shock between the two separate movements.
>>>
>>> I know that, I was a projectionist.
>>>
>>> But we were talking of a different thing, possible noise from "flutter
>>>from the sprocket wheel engaging and disengaging from the holes in the film"
>>
>> The movies shown on the US navy destroyer i was statoned on had
>> flutter on some movies. The guy who maintained the projector would
>> make an adjustment and the flutter, most of the time, would go away.
>
>Yes, that's a different thing, it is flutter on the video. I'd bet the
>sound was ok all the time?

It varied. Some of the old Republic Westerns fluttered on sound and
picture frames, but could mostly be adjusted out so we could see and
hear it. My first trip over to the Mediterranean Sea, our Captain was
new, so we got last pick for movies.

That meant in 1968 we got to watch B&W westerns 'introducing Audie
Murphy' or a very young John Wayne.

>The holes on the sides of the film, when the film has seen a fair bit of
>use, get enlarged. This causes the movement to not be smooth, in
>particular as each frame is shown it does not match exactly the position
>of other frames. You get flutter.
>
>The film passes a tiny window through which the light of the lantern
>shows. The film is pressed to the metal by metal "skids" on the sides,
>with adjustable pressure. The projectionist tries to use the smaller
>pressure possible to reduce wear. When there is flutter, he increases
>the pressure.

That was most likely the problem with some of the older movies they
showed us.

>Here, a photo from wikipedia showing the mechanism:
>
>https://en.wikipedia.org/wiki/Movie_projector#/media/File:Projmech.jpg
>
>What I called skids, in the photo is called "gate pressure plate", and
>the tiny window is the "aperture mask" (my first language is not
>English, I used different names). There is a "pressure plate tension
>knob" in the photo.

Our projector had a smiliar system, but one reel was in front for
supply, and the other one in the back for takeup.
--
Jim

On 2024-03-31 19:25, D.J. wrote:
> On Sun, 31 Mar 2024 16:13:04 +0200, "Carlos E.R."
> <robin_listas@es.invalid> wrote:
>> On 2024-03-29 15:50, D.J. wrote:
>>> On Fri, 29 Mar 2024 13:42:00 +0100, "Carlos E.R."
>>> <robin_listas@es.invalid> wrote:
>>>> On 2024-03-29 04:08, Lawrence D'Oliveiro wrote:
>>>>> On Fri, 29 Mar 2024 03:14:13 +0100, Carlos E.R. wrote:
>>>>>
>>>>>> Consider that the sound on movies was analogic and used this movement,
>>>>>> and had no such issues.
>>>>>
>>>>> That’s because the sound track was offset by a dozen or more frames from
>>>>> the corresponding image to show at that time. This allowed a loop of film
>>>>> to absorb the shock between the two separate movements.
>>>>
>>>> I know that, I was a projectionist.
>>>>
>>>> But we were talking of a different thing, possible noise from "flutter
>>> >from the sprocket wheel engaging and disengaging from the holes in the film"
>>>
>>> The movies shown on the US navy destroyer i was statoned on had
>>> flutter on some movies. The guy who maintained the projector would
>>> make an adjustment and the flutter, most of the time, would go away.
>>
>> Yes, that's a different thing, it is flutter on the video. I'd bet the
>> sound was ok all the time?
>
> It varied. Some of the old Republic Westerns fluttered on sound and
> picture frames, but could mostly be adjusted out so we could see and
> hear it. My first trip over to the Mediterranean Sea, our Captain was
> new, so we got last pick for movies.
>
> That meant in 1968 we got to watch B&W westerns 'introducing Audie
> Murphy' or a very young John Wayne.

Yeah, our cinema club was also at the end of the chain, so many films
were already damaged.

I guess you were using 16 mm material, not 35 mm. In my country (Spain)
at that time 35mm films got a license to show for 5 years (I think);
after that time, they were destroyed. Ancient movies were simply not
available unless the copies could make a profit in those 5 years.

But 16mm was a different circuit, not the commercial one. Older movies.

>
>> The holes on the sides of the film, when the film has seen a fair bit of
>> use, get enlarged. This causes the movement to not be smooth, in
>> particular as each frame is shown it does not match exactly the position
>> of other frames. You get flutter.
>>
>> The film passes a tiny window through which the light of the lantern
>> shows. The film is pressed to the metal by metal "skids" on the sides,
>> with adjustable pressure. The projectionist tries to use the smaller
>> pressure possible to reduce wear. When there is flutter, he increases
>> the pressure.
>
> That was most likely the problem with some of the older movies they
> showed us.
>
>> Here, a photo from wikipedia showing the mechanism:
>>
>> https://en.wikipedia.org/wiki/Movie_projector#/media/File:Projmech.jpg
>>
>> What I called skids, in the photo is called "gate pressure plate", and
>> the tiny window is the "aperture mask" (my first language is not
>> English, I used different names). There is a "pressure plate tension
>> knob" in the photo.
>
> Our projector had a smiliar system, but one reel was in front for
> supply, and the other one in the back for takeup.

That's typical of the 16 mm machines, that were put on a table,
temporary or portable setup, and smaller display :-)

--
Cheers, Carlos.

On Sun, 31 Mar 2024 20:27:37 +0200, "Carlos E.R."
<robin_listas@es.invalid> wrote:
>On 2024-03-31 19:25, D.J. wrote:
>> On Sun, 31 Mar 2024 16:13:04 +0200, "Carlos E.R."
>> <robin_listas@es.invalid> wrote:
>>> On 2024-03-29 15:50, D.J. wrote:
>>>> On Fri, 29 Mar 2024 13:42:00 +0100, "Carlos E.R."
>>>> <robin_listas@es.invalid> wrote:
>>>>> On 2024-03-29 04:08, Lawrence D'Oliveiro wrote:
>>>>>> On Fri, 29 Mar 2024 03:14:13 +0100, Carlos E.R. wrote:
>>>>>>
>>>>>>> Consider that the sound on movies was analogic and used this movement,
>>>>>>> and had no such issues.
>>>>>>
>>>>>> That’s because the sound track was offset by a dozen or more frames from
>>>>>> the corresponding image to show at that time. This allowed a loop of film
>>>>>> to absorb the shock between the two separate movements.
>>>>>
>>>>> I know that, I was a projectionist.
>>>>>
>>>>> But we were talking of a different thing, possible noise from "flutter
>>>> >from the sprocket wheel engaging and disengaging from the holes in the film"
>>>>
>>>> The movies shown on the US navy destroyer i was statoned on had
>>>> flutter on some movies. The guy who maintained the projector would
>>>> make an adjustment and the flutter, most of the time, would go away.
>>>
>>> Yes, that's a different thing, it is flutter on the video. I'd bet the
>>> sound was ok all the time?
>>
>> It varied. Some of the old Republic Westerns fluttered on sound and
>> picture frames, but could mostly be adjusted out so we could see and
>> hear it. My first trip over to the Mediterranean Sea, our Captain was
>> new, so we got last pick for movies.
>>
>> That meant in 1968 we got to watch B&W westerns 'introducing Audie
>> Murphy' or a very young John Wayne.
>
>Yeah, our cinema club was also at the end of the chain, so many films
>were already damaged.
>
>I guess you were using 16 mm material, not 35 mm. In my country (Spain)
>at that time 35mm films got a license to show for 5 years (I think);
>after that time, they were destroyed. Ancient movies were simply not
>available unless the copies could make a profit in those 5 years.
>
>But 16mm was a different circuit, not the commercial one. Older movies.

Ours was defiantly non-commercial. Via the Navy exchange system if I
remember correctly.

>>> The holes on the sides of the film, when the film has seen a fair bit of
>>> use, get enlarged. This causes the movement to not be smooth, in
>>> particular as each frame is shown it does not match exactly the position
>>> of other frames. You get flutter.
>>>
>>> The film passes a tiny window through which the light of the lantern
>>> shows. The film is pressed to the metal by metal "skids" on the sides,
>>> with adjustable pressure. The projectionist tries to use the smaller
>>> pressure possible to reduce wear. When there is flutter, he increases
>>> the pressure.
>>
>> That was most likely the problem with some of the older movies they
>> showed us.
>>
>>> Here, a photo from wikipedia showing the mechanism:
>>>
>>> https://en.wikipedia.org/wiki/Movie_projector#/media/File:Projmech.jpg
>>>
>>> What I called skids, in the photo is called "gate pressure plate", and
>>> the tiny window is the "aperture mask" (my first language is not
>>> English, I used different names). There is a "pressure plate tension
>>> knob" in the photo.
>>
>> Our projector had a smiliar system, but one reel was in front for
>> supply, and the other one in the back for takeup.
>
>That's typical of the 16 mm machines, that were put on a table,
>temporary or portable setup, and smaller display :-)

He had a metal stand that went between two of the mess deck tables. It
was fun trying to watch a movie if the sea was a bit rough. Projector
and table would sometimes wobble in different directions.

More than once we asked why there wasn't a way to lock them in place.
--
Jim

On 2024-03-31 22:37, D.J. wrote:
> On Sun, 31 Mar 2024 20:27:37 +0200, "Carlos E.R."
> <robin_listas@es.invalid> wrote:
>> On 2024-03-31 19:25, D.J. wrote:
>>> On Sun, 31 Mar 2024 16:13:04 +0200, "Carlos E.R."
>>> <robin_listas@es.invalid> wrote:
>>>> On 2024-03-29 15:50, D.J. wrote:
>>>>> On Fri, 29 Mar 2024 13:42:00 +0100, "Carlos E.R."
>>>>> <robin_listas@es.invalid> wrote:
>>>>>> On 2024-03-29 04:08, Lawrence D'Oliveiro wrote:
>>>>>>> On Fri, 29 Mar 2024 03:14:13 +0100, Carlos E.R. wrote:
>>>>>>>
>>>>>>>> Consider that the sound on movies was analogic and used this movement,
>>>>>>>> and had no such issues.
>>>>>>>
>>>>>>> That’s because the sound track was offset by a dozen or more frames from
>>>>>>> the corresponding image to show at that time. This allowed a loop of film
>>>>>>> to absorb the shock between the two separate movements.
>>>>>>
>>>>>> I know that, I was a projectionist.
>>>>>>
>>>>>> But we were talking of a different thing, possible noise from "flutter
>>>>> >from the sprocket wheel engaging and disengaging from the holes in the film"
>>>>>
>>>>> The movies shown on the US navy destroyer i was statoned on had
>>>>> flutter on some movies. The guy who maintained the projector would
>>>>> make an adjustment and the flutter, most of the time, would go away.
>>>>
>>>> Yes, that's a different thing, it is flutter on the video. I'd bet the
>>>> sound was ok all the time?
>>>
>>> It varied. Some of the old Republic Westerns fluttered on sound and
>>> picture frames, but could mostly be adjusted out so we could see and
>>> hear it. My first trip over to the Mediterranean Sea, our Captain was
>>> new, so we got last pick for movies.
>>>
>>> That meant in 1968 we got to watch B&W westerns 'introducing Audie
>>> Murphy' or a very young John Wayne.
>>
>> Yeah, our cinema club was also at the end of the chain, so many films
>> were already damaged.
>>
>> I guess you were using 16 mm material, not 35 mm. In my country (Spain)
>> at that time 35mm films got a license to show for 5 years (I think);
>> after that time, they were destroyed. Ancient movies were simply not
>> available unless the copies could make a profit in those 5 years.
>>
>> But 16mm was a different circuit, not the commercial one. Older movies.
>
> Ours was defiantly non-commercial. Via the Navy exchange system if I
> remember correctly.

Ah.

>
>
>>>> The holes on the sides of the film, when the film has seen a fair bit of
>>>> use, get enlarged. This causes the movement to not be smooth, in
>>>> particular as each frame is shown it does not match exactly the position
>>>> of other frames. You get flutter.
>>>>
>>>> The film passes a tiny window through which the light of the lantern
>>>> shows. The film is pressed to the metal by metal "skids" on the sides,
>>>> with adjustable pressure. The projectionist tries to use the smaller
>>>> pressure possible to reduce wear. When there is flutter, he increases
>>>> the pressure.
>>>
>>> That was most likely the problem with some of the older movies they
>>> showed us.
>>>
>>>> Here, a photo from wikipedia showing the mechanism:
>>>>
>>>> https://en.wikipedia.org/wiki/Movie_projector#/media/File:Projmech.jpg
>>>>
>>>> What I called skids, in the photo is called "gate pressure plate", and
>>>> the tiny window is the "aperture mask" (my first language is not
>>>> English, I used different names). There is a "pressure plate tension
>>>> knob" in the photo.
>>>
>>> Our projector had a smiliar system, but one reel was in front for
>>> supply, and the other one in the back for takeup.
>>
>> That's typical of the 16 mm machines, that were put on a table,
>> temporary or portable setup, and smaller display :-)
>
> He had a metal stand that went between two of the mess deck tables. It
> was fun trying to watch a movie if the sea was a bit rough. Projector
> and table would sometimes wobble in different directions.
>
> More than once we asked why there wasn't a way to lock them in place.

:-D

I just remembered an anecdote, things not designed for naval usage. Not
sure of the details, it was long ago, I just live in a city with a navy
base and harbour.

Imagine somewhere in the 80's, that someone on the navy (Spain) decides
to buy a computer or two to install in a submarine. So they go and buy I
think it was three Amstrad PC1512 with hard disk. They were guaranteed
for a number of years. They just bought them on a computer shop.

Less of a week later they come back, all the computers broken. The shop
is surprised but replaces them.

Less of a week later they come back, all the computers broken. The shop
is very surprised, I don't know if they replaced them silently or
started asking questions that time or the next.

When they found out they were installed on a submarine they cancelled
the contract real fast. Apparently, the machines failed soon after they
set sail with the old diesels. The vessel vibrated and killed the hard
disks fast :-D

--
Cheers, Carlos.

On Sun, 31 Mar 2024 23:03:21 +0200, "Carlos E.R."
<robin_listas@es.invalid> wrote:
>On 2024-03-31 22:37, D.J. wrote:
>> On Sun, 31 Mar 2024 20:27:37 +0200, "Carlos E.R."
>> <robin_listas@es.invalid> wrote:
>>> On 2024-03-31 19:25, D.J. wrote:
>>>> On Sun, 31 Mar 2024 16:13:04 +0200, "Carlos E.R."
>>>> <robin_listas@es.invalid> wrote:
>>>>> On 2024-03-29 15:50, D.J. wrote:
>>>>>> On Fri, 29 Mar 2024 13:42:00 +0100, "Carlos E.R."
>>>>>> <robin_listas@es.invalid> wrote:
>>>>>>> On 2024-03-29 04:08, Lawrence D'Oliveiro wrote:
>>>>>>>> On Fri, 29 Mar 2024 03:14:13 +0100, Carlos E.R. wrote:
>>>>>>>>
>>>>>>>>> Consider that the sound on movies was analogic and used this movement,
>>>>>>>>> and had no such issues.
>>>>>>>>
>>>>>>>> That’s because the sound track was offset by a dozen or more frames from
>>>>>>>> the corresponding image to show at that time. This allowed a loop of film
>>>>>>>> to absorb the shock between the two separate movements.
>>>>>>>
>>>>>>> I know that, I was a projectionist.
>>>>>>>
>>>>>>> But we were talking of a different thing, possible noise from "flutter
>>>>>> >from the sprocket wheel engaging and disengaging from the holes in the film"
>>>>>>
>>>>>> The movies shown on the US navy destroyer i was statoned on had
>>>>>> flutter on some movies. The guy who maintained the projector would
>>>>>> make an adjustment and the flutter, most of the time, would go away.
>>>>>
>>>>> Yes, that's a different thing, it is flutter on the video. I'd bet the
>>>>> sound was ok all the time?
>>>>
>>>> It varied. Some of the old Republic Westerns fluttered on sound and
>>>> picture frames, but could mostly be adjusted out so we could see and
>>>> hear it. My first trip over to the Mediterranean Sea, our Captain was
>>>> new, so we got last pick for movies.
>>>>
>>>> That meant in 1968 we got to watch B&W westerns 'introducing Audie
>>>> Murphy' or a very young John Wayne.
>>>
>>> Yeah, our cinema club was also at the end of the chain, so many films
>>> were already damaged.
>>>
>>> I guess you were using 16 mm material, not 35 mm. In my country (Spain)
>>> at that time 35mm films got a license to show for 5 years (I think);
>>> after that time, they were destroyed. Ancient movies were simply not
>>> available unless the copies could make a profit in those 5 years.
>>>
>>> But 16mm was a different circuit, not the commercial one. Older movies.
>>
>> Ours was defiantly non-commercial. Via the Navy exchange system if I
>> remember correctly.
>
>Ah.
>
>>
>>
>>>>> The holes on the sides of the film, when the film has seen a fair bit of
>>>>> use, get enlarged. This causes the movement to not be smooth, in
>>>>> particular as each frame is shown it does not match exactly the position
>>>>> of other frames. You get flutter.
>>>>>
>>>>> The film passes a tiny window through which the light of the lantern
>>>>> shows. The film is pressed to the metal by metal "skids" on the sides,
>>>>> with adjustable pressure. The projectionist tries to use the smaller
>>>>> pressure possible to reduce wear. When there is flutter, he increases
>>>>> the pressure.
>>>>
>>>> That was most likely the problem with some of the older movies they
>>>> showed us.
>>>>
>>>>> Here, a photo from wikipedia showing the mechanism:
>>>>>
>>>>> https://en.wikipedia.org/wiki/Movie_projector#/media/File:Projmech.jpg
>>>>>
>>>>> What I called skids, in the photo is called "gate pressure plate", and
>>>>> the tiny window is the "aperture mask" (my first language is not
>>>>> English, I used different names). There is a "pressure plate tension
>>>>> knob" in the photo.
>>>>
>>>> Our projector had a smiliar system, but one reel was in front for
>>>> supply, and the other one in the back for takeup.
>>>
>>> That's typical of the 16 mm machines, that were put on a table,
>>> temporary or portable setup, and smaller display :-)
>>
>> He had a metal stand that went between two of the mess deck tables. It
>> was fun trying to watch a movie if the sea was a bit rough. Projector
>> and table would sometimes wobble in different directions.
>>
>> More than once we asked why there wasn't a way to lock them in place.
>
>:-D
>
>
>I just remembered an anecdote, things not designed for naval usage. Not
>sure of the details, it was long ago, I just live in a city with a navy
>base and harbour.
>
>Imagine somewhere in the 80's, that someone on the navy (Spain) decides
>to buy a computer or two to install in a submarine. So they go and buy I
>think it was three Amstrad PC1512 with hard disk. They were guaranteed
>for a number of years. They just bought them on a computer shop.
>
>Less of a week later they come back, all the computers broken. The shop
>is surprised but replaces them.
>
>Less of a week later they come back, all the computers broken. The shop
>is very surprised, I don't know if they replaced them silently or
>started asking questions that time or the next.
>
>When they found out they were installed on a submarine they cancelled
>the contract real fast. Apparently, the machines failed soon after they
>set sail with the old diesels. The vessel vibrated and killed the hard
>disks fast :-D

Yeah, I can see that. We had steam boilers to drive the propellor
shafts. They could vibrate to with speed changes.

But we didn't have computers. That was still in the days where a
computer wouldn't fit, the width of the ship was 48 feet.
--
Jim

On Mon, 01 Apr 2024 09:20:50 -0500, D.J. wrote:

> That was still in the days where a
> computer wouldn't fit, the width of the ship was 48 feet.

But surely a PDP-8 would fit comfortably under one arm.

And you could use the other arm to carry/drag an ASR-33 teletype.

According to Lawrence D'Oliveiro <ldo@nz.invalid>:
>On Mon, 01 Apr 2024 09:20:50 -0500, D.J. wrote:
>
>> That was still in the days where a
>> computer wouldn't fit, the width of the ship was 48 feet.
>
>But surely a PDP-8 would fit comfortably under one arm.

Your arms must be longer than mine. A PDP-8/S or 8/L perhaps,
but a PDP-8 was the size of a dishwasher.

>And you could use the other arm to carry/drag an ASR-33 teletype.

That's slightly more plausible.

--
Regards,
John Levine, johnl@taugh.com, Primary Perpetrator of "The Internet for Dummies",
Please consider the environment before reading this e-mail. https://jl.ly