UK TNMOC

[Adrian Caspersz]

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.

[D]

Post by Adrian Caspersz
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

[Sn!pe]

Post by D
Daniel

[Kerr-Mudd, John]

On Wed, 24 Jan 2024 15:13:02 +0000

Post by D
Daniel

I see the legs of a Sn!pe are very long, ideal for stalking.

[Sn!pe]

Post by Kerr-Mudd, John
On Wed, 24 Jan 2024 15:13:02 +0000

Post by D
Daniel

I see the legs of a Sn!pe are very long, ideal for stalking.

Hardly stalking, I've been here for years.

[D]

Post by Sn!pe

Post by Kerr-Mudd, John
On Wed, 24 Jan 2024 15:13:02 +0000

Post by D
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

[Bob Eager]

Post by D

Post by Adrian Caspersz
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.

[D]

Post by Bob Eager

Post by D

Post by Adrian Caspersz
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! =)

[Charlie Gibbs]

Post by Adrian Caspersz
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...

Post by Adrian Caspersz
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.

[Thomas Prufer]

Post by Charlie Gibbs

Post by Adrian Caspersz
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...

Post by Adrian Caspersz
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

[Charlie Gibbs]

Post by Thomas Prufer

Post by Charlie Gibbs

Post by Adrian Caspersz
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.

[Lawrence D'Oliveiro]

Post by Adrian Caspersz
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?

[Charlie Gibbs]

Post by Lawrence D'Oliveiro

Post by Adrian Caspersz
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.

[Carlos E.R.]

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

...

Post by Charlie Gibbs
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.

[Lawrence D'Oliveiro]

Post by Carlos E.R.
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.

[Carlos E.R.]

Post by Lawrence D'Oliveiro

Post by Carlos E.R.
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"

[D.J.]

On Fri, 29 Mar 2024 13:42:00 +0100, "Carlos E.R."

Post by Carlos E.R.

Post by Carlos E.R.
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.

[Carlos E.R.]

Post by D.J.
On Fri, 29 Mar 2024 13:42:00 +0100, "Carlos E.R."

Post by Carlos E.R.

Post by Lawrence D'Oliveiro

Post by Carlos E.R.
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:

Loading Image...

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.

[D.J.]

On Sun, 31 Mar 2024 16:13:04 +0200, "Carlos E.R."

Post by Carlos E.R.

Post by D.J.
On Fri, 29 Mar 2024 13:42:00 +0100, "Carlos E.R."

Post by Carlos E.R.

Post by Carlos E.R.
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.

Post by Carlos E.R.
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.

Post by Carlos E.R.
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.

[Carlos E.R.]

Post by D.J.
On Sun, 31 Mar 2024 16:13:04 +0200, "Carlos E.R."

Post by Carlos E.R.

Post by D.J.
On Fri, 29 Mar 2024 13:42:00 +0100, "Carlos E.R."

Post by Carlos E.R.

Post by Lawrence D'Oliveiro

Post by Carlos E.R.
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.

Post by D.J.

Post by Carlos E.R.
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.

Post by Carlos E.R.
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 :-)

[D.J.]

On Sun, 31 Mar 2024 20:27:37 +0200, "Carlos E.R."

Post by Carlos E.R.

Post by D.J.
On Sun, 31 Mar 2024 16:13:04 +0200, "Carlos E.R."

Post by Carlos E.R.

Post by D.J.
On Fri, 29 Mar 2024 13:42:00 +0100, "Carlos E.R."

Post by Carlos E.R.

Post by Carlos E.R.
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.

Post by Carlos E.R.

Post by D.J.

Post by Carlos E.R.
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.

Post by Carlos E.R.
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.

[Carlos E.R.]

Post by D.J.
On Sun, 31 Mar 2024 20:27:37 +0200, "Carlos E.R."

Post by Carlos E.R.

Post by D.J.
On Sun, 31 Mar 2024 16:13:04 +0200, "Carlos E.R."

Post by Carlos E.R.

Post by D.J.
On Fri, 29 Mar 2024 13:42:00 +0100, "Carlos E.R."

Post by Carlos E.R.

Post by Lawrence D'Oliveiro

Post by Carlos E.R.
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.

Post by D.J.

Post by Carlos E.R.

Post by D.J.

Post by Carlos E.R.
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.

Post by Carlos E.R.
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

[D.J.]

On Sun, 31 Mar 2024 23:03:21 +0200, "Carlos E.R."

Post by Carlos E.R.

Post by D.J.
On Sun, 31 Mar 2024 20:27:37 +0200, "Carlos E.R."

Post by Carlos E.R.

Post by D.J.
On Sun, 31 Mar 2024 16:13:04 +0200, "Carlos E.R."

Post by Carlos E.R.

Post by D.J.
On Fri, 29 Mar 2024 13:42:00 +0100, "Carlos E.R."

Post by Carlos E.R.

Post by Carlos E.R.
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.

Post by D.J.

Post by Carlos E.R.

Post by D.J.

Post by Carlos E.R.
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.

Post by Carlos E.R.
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.

[Lawrence D'Oliveiro]

Post by D.J.
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.

[John Levine]

Post by Lawrence D'Oliveiro

Post by D.J.
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.

Post by Lawrence D'Oliveiro
And you could use the other arm to carry/drag an ASR-33 teletype.

That's slightly more plausible.

[Charlie Gibbs]

Post by John Levine

Post by Lawrence D'Oliveiro

Post by D.J.
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.

Post by Lawrence D'Oliveiro
And you could use the other arm to carry/drag an ASR-33 teletype.

That's slightly more plausible.

If your arm is _really_ strong. I still have a 35RO;
I built a dolly for it.

[D.J.]

On Tue, 2 Apr 2024 00:29:58 -0000 (UTC), Lawrence D'Oliveiro

Post by Lawrence D'Oliveiro

Post by D.J.
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.

Three were teletypes in the radio room.

The computers on board were electro-mechanical ones used to aim the
two guns. The air search missiles had something, but I don't know what
it was.

[Lawrence D'Oliveiro]

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

The computers on board were electro-mechanical ones used to aim the two
guns.

I thought you said a computer wouldn’t fit.

[D.J.]

On Thu, 4 Apr 2024 06:00:46 -0000 (UTC), Lawrence D'Oliveiro

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

The computers on board were electro-mechanical ones used to aim the two
guns.

I thought you said a computer wouldn’t fit.

Not vacuum tubes/valves, servos and gears.

[D.J.]

On Thu, 4 Apr 2024 06:00:46 -0000 (UTC), Lawrence D'Oliveiro

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

The computers on board were electro-mechanical ones used to aim the two
guns.

I thought you said a computer wouldn’t fit.

Here ya go. They are large devices.

https://arstechnica.com/information-technology/2020/05/gears-of-war-when-mechanical-analog-computers-ruled-the-waves/