I was watching a never-previously-broadcast *colour* version of Last Night
at the Sunday Palladium (shown a year so ago on Talking Pictures TV), made
as an experiment before PAL broadcasts began. As far as I could tell, it had
not been film-recorded.

That led me to think... if it had been originally recorded on 2" Quad tape,
would that tape still be playable today (assuming it had been stored in
ideal conditions)? I imagine at some stage it was converted from analogue
video to a modern digital video format for broadcast by TPTV, but would Quad
VT last long enough to do that during the time that digital formats have
been used, or would it have been copied to another more recent analogue
format (one of the 1" or 3/4" formats) some time in the past before the Quad
tape deteriorated?

In message <uma38a$2mnhj$2@dont-email.me> at Sun, 24 Dec 2023 20:10:32,
NY <me@privacy.invalid> writes
>I was watching a never-previously-broadcast *colour* version of Last
>Night at the Sunday Palladium (shown a year so ago on Talking Pictures
>TV), made as an experiment before PAL broadcasts began. As far as I
>could tell, it had not been film-recorded.

Did you get the impression that it _had_ been PAL, just before actual
broadcasting began, or one of the several other schemes the Beeb tried
out? (I presume not 405, or you'd have mentioned it. I know they did do
some 405 colour trials, including a special version of NTSC!)
>
>That led me to think... if it had been originally recorded on 2" Quad
>tape, would that tape still be playable today (assuming it had been
>stored in ideal conditions)? I imagine at some stage it was converted
>from analogue video to a modern digital video format for broadcast by
>TPTV, but would Quad VT last long enough to do that during the time
>that digital formats have been used, or would it have been copied to
>another more recent analogue format (one of the 1" or 3/4" formats)
>some time in the past before the Quad tape deteriorated?

Good wonder. I suspect you're right that it went via something else.
Probably hard to tell unless someone knows a format-specific artefact to
look for: if done with professional kit, I expect a generation or two of
extra copying would not degrade it enough to tell.
--
J. P. Gilliver. UMRA: 1960/<1985 MB++G()AL-IS-Ch++(p)Ar@T+H+Sh0!:`)DNAf

Radio 4 is the civilising influence in this country ... I think it is the most
important institution in this country. - John Humphrys, Radio Times
7-13/06/2003

"J. P. Gilliver" <G6JPG@255soft.uk> wrote in message
news:nYTLf9u9jNilFwLp@255soft.uk...
> In message <uma38a$2mnhj$2@dont-email.me> at Sun, 24 Dec 2023 20:10:32, NY
> <me@privacy.invalid> writes
>>I was watching a never-previously-broadcast *colour* version of Last Night
>>at the Sunday Palladium (shown a year so ago on Talking Pictures TV), made
>>as an experiment before PAL broadcasts began. As far as I could tell, it
>>had not been film-recorded.
>
> Did you get the impression that it _had_ been PAL, just before actual
> broadcasting began, or one of the several other schemes the Beeb tried
> out? (I presume not 405, or you'd have mentioned it. I know they did do
> some 405 colour trials, including a special version of NTSC!)

I wondered whether it had been PAL or NTSC. The resolution *looked* to be
625 rather 525, so if it was NTSC, it was probably 625 NTSC. Having said
that, by the time TPTV transmitted it, the horizontal resolution had been
reduced to 544x576 rather than 720x576, which may have hidden some analogue
upscaling from 405 to 625. There was a fair amount of ghosting on some of
the cameras.

What I did notice was the very poor brightness/contrast matching between
cameras showing the same scene from different angles. There was also a
catastrophe with the registration of one camera: they showed a shot from a
certain angle, cut to a shot from another angle and then back to the
original - and in that short time the R, G and B had become very widely
separated: horizontal and vertical translation, different picture size and
some picture rotation of one colour compared with another. They didn't show
any more shots from that angle (camera) for a long time, though it looked as
if a bit of hasty real-time fettling got it going before the end of the
programme.

"Graham. " <graham-usenet@mail.com> wrote in message
news:umha4l$3uf3u$1@dont-email.me...
> "NY" <me@privacy.invalid> Wrote in message:
>> I was watching a never-previously-broadcast *colour* version of Last
>> Night at the Sunday Palladium
>
> Was that a real show, a Mollyprop/Spooner joke, or just a typo on
> your part?
>
> I've only heard of "Sunday Night at the London Palladium"

A typo or brain-on-reduced-power problem ;-) I knew what I *meant* ;-)

On 25/12/2023 01:21, J. P. Gilliver wrote:
> Good wonder. I suspect you're right that it went via something else.
> Probably hard to tell unless someone knows a format-specific artefact to
> look for: if done with professional kit, I expect a generation or two of
> extra copying would not degrade it enough to tell.

It's often possible to recognise Quad; sometimes you can see a glitch
every 15 lines, either a slight hiccup in the sync or change in colour.

--
rgds
LAurence
<><

"Bother," said Pooh, as Windows crashed into piglet.
~~~ Random (signature) 1.6.1

In message <D9mdnb-muu4-hw34nZ2dnZfqn_adnZ2d@brightview.co.uk> at Sat,
30 Dec 2023 13:27:01, Laurence Taylor <laurence@nospam.plus.com> writes
>On 25/12/2023 01:21, J. P. Gilliver wrote:
>> Good wonder. I suspect you're right that it went via something else.
>> Probably hard to tell unless someone knows a format-specific artefact to
>> look for: if done with professional kit, I expect a generation or two of
>> extra copying would not degrade it enough to tell.
>
>It's often possible to recognise Quad; sometimes you can see a glitch
>every 15 lines, either a slight hiccup in the sync or change in colour.
>
>
What I meant was - yes, those who know might well be able to tell what
it was _originally_ on, but - if done with good-quality gear by someone
who knows what they're doing - it probably _isn't_ possible to tell
whether what you're seeing is direct from the Quad (or whatever), or has
been stored on something else (1" or whatever) for most of the
intervening time.
--
J. P. Gilliver. UMRA: 1960/<1985 MB++G()AL-IS-Ch++(p)Ar@T+H+Sh0!:`)DNAf

As for cooking, what a bore that is. It's such a faff, thinking of what to
have, buying it and cooking it and clearing up, then all you do is eat it -
and have to start all over again next day. Hunter Davies, RT 2017/2/4-10

"J. P. Gilliver" <G6JPG@255soft.uk> wrote in message
news:1pU81bzPQCklFwqj@255soft.uk...
> In message <D9mdnb-muu4-hw34nZ2dnZfqn_adnZ2d@brightview.co.uk> at Sat, 30
> Dec 2023 13:27:01, Laurence Taylor <laurence@nospam.plus.com> writes
>>On 25/12/2023 01:21, J. P. Gilliver wrote:
>>> Good wonder. I suspect you're right that it went via something else.
>>> Probably hard to tell unless someone knows a format-specific artefact to
>>> look for: if done with professional kit, I expect a generation or two of
>>> extra copying would not degrade it enough to tell.
>>
>>It's often possible to recognise Quad; sometimes you can see a glitch
>>every 15 lines, either a slight hiccup in the sync or change in colour.
>>
>>
> What I meant was - yes, those who know might well be able to tell what it
> was _originally_ on, but - if done with good-quality gear by someone who
> knows what they're doing - it probably _isn't_ possible to tell whether
> what you're seeing is direct from the Quad (or whatever), or has been
> stored on something else (1" or whatever) for most of the intervening
> time.

I presume that every recording technology imprints its own "footprint" on
the signal because of restrictions of the format. The Quad banding is an
extreme example of this. Whether those footprints are visible to the viewer,
or in most cases is only detectable with an oscilloscope or vectorscope, is
another matter.

I wonder if any archive material still exists as videotape nowadays, or
whether archives have digitised everything so (barring catastrophic
corruption of DAT or HDD masters) the recording does not deteriorate any
further over time.

I have been surprised when TV news reports are included in documentaries
about historical events (even as recent as the 1980s), how poor the picture
quality is sometimes - as if the only copy in existence is a 2nd generation
VHS ;-) Of course in some cases documentary makers deliberately degrade the
quality with ageing effects, to say to the viewer "this is archive, not a
modern recording". And so you get monstrosities such as film scratches and
dirt on an ENG (and therefore video camera and videotape) report. Sometimes
the effects are even more crass - I remember a programme about the Iranian
Embassy siege in the 80s, and the often-seen footage "filmed" with video
cameras had been fed through an effects box which added film scratches, film
gamma changes, fake film grain and venetian blinds. A caption "archive"
would have been so much less intrusive.

What is the typical life of videotape as a means of long-term storage,
before the oxide starts to shed or the tape base starts to become brittle?

In message <un0m4v$2k453$1@dont-email.me> at Tue, 2 Jan 2024 09:46:33,
NY <me@privacy.invalid> writes
>"J. P. Gilliver" <G6JPG@255soft.uk> wrote in message
>news:1pU81bzPQCklFwqj@255soft.uk...
>> In message <D9mdnb-muu4-hw34nZ2dnZfqn_adnZ2d@brightview.co.uk> at
>>Sat, 30 Dec 2023 13:27:01, Laurence Taylor <laurence@nospam.plus.com>
>>writes
>>>On 25/12/2023 01:21, J. P. Gilliver wrote:
>>>> Good wonder. I suspect you're right that it went via something else.
>>>> Probably hard to tell unless someone knows a format-specific artefact to
>>>> look for: if done with professional kit, I expect a generation or two of
>>>> extra copying would not degrade it enough to tell.
>>>
>>>It's often possible to recognise Quad; sometimes you can see a glitch
>>>every 15 lines, either a slight hiccup in the sync or change in colour.
>>>
>>>
>> What I meant was - yes, those who know might well be able to tell
>>what it was _originally_ on, but - if done with good-quality gear by
>>someone who knows what they're doing - it probably _isn't_ possible
>>to tell whether what you're seeing is direct from the Quad (or
>>whatever), or has been stored on something else (1" or whatever) for
>>most of the intervening time.
>
>I presume that every recording technology imprints its own "footprint"
>on the signal because of restrictions of the format. The Quad banding
>is an extreme example of this. Whether those footprints are visible to
>the viewer, or in most cases is only detectable with an oscilloscope or
>vectorscope, is another matter.

Indeed. The quad banding is indeed visible to those who know what to
look for. (Another visible effect - though not due to the recording
format - was visible on reports from the Falklands, when equipment
presumably not designed for such field strengths was used in close
proximity to ship's radar; it occurred to me at the time that this might
be giving away information about the pulse characteristics thereof which
would be of use to the enemy [it clearly wasn't just a plain beam], but
nothing such has ever been revealed.)
>
>I wonder if any archive material still exists as videotape nowadays, or
>whether archives have digitised everything so (barring catastrophic
>corruption of DAT or HDD masters) the recording does not deteriorate
>any further over time.

One would hope so, but it's an expensive business, so probably not. Plus
the oft-raised point that - for some archives, anyway - the hours of
archive material they hold exceed the remaining use hours of the
machines they have still working, so they're kept for when it's actually
required for something rather than continuous background conversion.
>
>I have been surprised when TV news reports are included in
>documentaries about historical events (even as recent as the 1980s),
>how poor the picture quality is sometimes - as if the only copy in
>existence is a 2nd generation VHS ;-) Of course in some cases

May of course be the case of course.

>documentary makers deliberately degrade the quality with ageing
>effects, to say to the viewer "this is archive, not a modern
>recording". And so you get monstrosities such as film scratches and
>dirt on an ENG (and therefore video camera and videotape) report.
>Sometimes the effects are even more crass - I remember a programme
>about the Iranian Embassy siege in the 80s, and the often-seen footage
>"filmed" with video cameras had been fed through an effects box which
>added film scratches, film gamma changes, fake film grain and venetian
>blinds. A caption "archive" would have been so much less intrusive.

They'd far rather do such effects than use on-screen captioning: they
seem to have a horror thereof. As another example, news reports _never_
timestamp footage that isn't immediately new, so - especially on rolling
news channels - you think you're going to get a new report, but get
shown something you've seen many times before, presented as if new.
>
>What is the typical life of videotape as a means of long-term storage,
>before the oxide starts to shed or the tape base starts to become
>brittle?

I suspect there's a strong element of "luck of the draw", even assuming
- which may well not be the case in many cases - it's been kept in
optimal conditions; certainly for audio tape, some has lasted for a very
long time. (It's actually be interesting to know what _is_ the oldest
such recording still playable. [Would it be paper? Not sure when plastic
backing came in. And of course there might still be some of the original
steel tape material - Blattnerphone was it? - though maybe nothing to
play it on, as well as earlier - something beginning with V, Valdemar
was it? - magnetic discs.])
--
J. P. Gilliver. UMRA: 1960/<1985 MB++G()AL-IS-Ch++(p)Ar@T+H+Sh0!:`)DNAf

.... each generation tends to imagine that its attitude to sex strikes just
about the right balance; that by comparison its predecessors were prim and
embarrassed, its successors sex-obsessed and pornified. - Julian Barnes, Radio
Times 9-15 March 2013

In article <UyKBGnFHRAllFwn$@255soft.uk>,
J. P. Gilliver <G6JPG@255soft.uk> wrote:
> In message <un0m4v$2k453$1@dont-email.me> at Tue, 2 Jan 2024 09:46:33,
> NY <me@privacy.invalid> writes
> >"J. P. Gilliver" <G6JPG@255soft.uk> wrote in message
> >news:1pU81bzPQCklFwqj@255soft.uk...
> >> In message <D9mdnb-muu4-hw34nZ2dnZfqn_adnZ2d@brightview.co.uk> at
> >>Sat, 30 Dec 2023 13:27:01, Laurence Taylor <laurence@nospam.plus.com>
> >>writes
> >>>On 25/12/2023 01:21, J. P. Gilliver wrote:
> >>>> Good wonder. I suspect you're right that it went via something else.
> >>>> Probably hard to tell unless someone knows a format-specific artefact to
> >>>> look for: if done with professional kit, I expect a generation or two of
> >>>> extra copying would not degrade it enough to tell.
> >>>
> >>>It's often possible to recognise Quad; sometimes you can see a glitch
> >>>every 15 lines, either a slight hiccup in the sync or change in colour.
> >>>
> >>>
> >> What I meant was - yes, those who know might well be able to tell
> >>what it was _originally_ on, but - if done with good-quality gear by
> >>someone who knows what they're doing - it probably _isn't_ possible
> >>to tell whether what you're seeing is direct from the Quad (or
> >>whatever), or has been stored on something else (1" or whatever) for
> >>most of the intervening time.
> >
> >I presume that every recording technology imprints its own "footprint"
> >on the signal because of restrictions of the format. The Quad banding
> >is an extreme example of this. Whether those footprints are visible to
> >the viewer, or in most cases is only detectable with an oscilloscope or
> >vectorscope, is another matter.

> Indeed. The quad banding is indeed visible to those who know what to
> look for. (Another visible effect - though not due to the recording
> format - was visible on reports from the Falklands, when equipment
> presumably not designed for such field strengths was used in close
> proximity to ship's radar; it occurred to me at the time that this might
> be giving away information about the pulse characteristics thereof which
> would be of use to the enemy [it clearly wasn't just a plain beam], but
> nothing such has ever been revealed.)

Such effects were also seen on the Apollo splashdown pictures - also from
an aircraft carrier.

> >
> >I wonder if any archive material still exists as videotape nowadays, or
> >whether archives have digitised everything so (barring catastrophic
> >corruption of DAT or HDD masters) the recording does not deteriorate
> >any further over time.

> One would hope so, but it's an expensive business, so probably not. Plus
> the oft-raised point that - for some archives, anyway - the hours of
> archive material they hold exceed the remaining use hours of the
> machines they have still working, so they're kept for when it's actually
> required for something rather than continuous background conversion.

I remember being involved in Standards Converting 405 material to 625 for
archive purposes.

--
from KT24 in Surrey, England - sent from my RISC OS 4té²
"I'd rather die of exhaustion than die of boredom" Thomas Carlyle

In message <5b1c724d7echarles@candehope.me.uk> at Tue, 2 Jan 2024
14:08:16, charles <charles@candehope.me.uk> writes
>In article <UyKBGnFHRAllFwn$@255soft.uk>,
> J. P. Gilliver <G6JPG@255soft.uk> wrote:
>> In message <un0m4v$2k453$1@dont-email.me> at Tue, 2 Jan 2024 09:46:33,
>> NY <me@privacy.invalid> writes
[]
>> >I wonder if any archive material still exists as videotape nowadays, or
>> >whether archives have digitised everything so (barring catastrophic
>> >corruption of DAT or HDD masters) the recording does not deteriorate
>> >any further over time.
>
>> One would hope so, but it's an expensive business, so probably not. Plus
>> the oft-raised point that - for some archives, anyway - the hours of
>> archive material they hold exceed the remaining use hours of the
>> machines they have still working, so they're kept for when it's actually
>> required for something rather than continuous background conversion.
>
>I remember being involved in Standards Converting 405 material to 625 for
>archive purposes.
>
I wasn't thinking so much of the electronics, as the heads. The skills
to repair the electronics - though I suspect increasingly rare -
probably are still findable (and the circuitry of the machines is
probably at least moderately well documented), but that to make the
heads - and the machines and materials required to do so - will be much
rarer. Perhaps other mechanical parts too.
--
J. P. Gilliver. UMRA: 1960/<1985 MB++G()AL-IS-Ch++(p)Ar@T+H+Sh0!:`)DNAf

gazing at someone in distress is prurient and rude.
- Alison Graham, RT 2015/6/20-26

On 02/01/2024 14:45, J. P. Gilliver wrote:

> I wasn't thinking so much of the electronics, as the heads. The skills
> to repair the electronics - though I suspect increasingly rare -
> probably are still findable (and the circuitry of the machines is
> probably at least moderately well documented), but that to make the
> heads - and the machines and materials required to do so - will be much
> rarer. Perhaps other mechanical parts too.

The heads are the only real problem. Everything else can be made using a
lathe and a milling machine if you have an old one as a pattern or the
drawings. Making heads is a different kettle of fish.

In the early days of digital audio, Betamax video recorders were used to
carry the digital signal on tape. The amount of tape which exists and
which people would like to archive now exceeds the expected life of all
the Betamax heads currently in existence, and it would be too hard or
expensive to rebuild the head making machinery.

--
Tciao for Now!

John.

In message <kvioenFb164U1@mid.individual.net> at Tue, 2 Jan 2024
15:29:25, John Williamson <johnwilliamson@btinternet.com> writes
>On 02/01/2024 14:45, J. P. Gilliver wrote:
>
>> I wasn't thinking so much of the electronics, as the heads. The skills
>> to repair the electronics - though I suspect increasingly rare -
>> probably are still findable (and the circuitry of the machines is
>> probably at least moderately well documented), but that to make the
>> heads - and the machines and materials required to do so - will be much
>> rarer. Perhaps other mechanical parts too.
>
>The heads are the only real problem. Everything else can be made using
>a lathe and a milling machine if you have an old one as a pattern or
>the drawings. Making heads is a different kettle of fish.

That's what I suspected.
>
>In the early days of digital audio, Betamax video recorders were used
>to carry the digital signal on tape. The amount of tape which exists

Beta might have been the choice, but it was my understanding that they
created standard video signals (and reasonably low bandwidth at that),
so presumably they could have been recorded on VHS or V2000 too.

IIRR, it's also why we have the rather odd sampling rate of 44100 hertz
- it sort of fell out of the pseudo-video waveform creation, and the
SECAM and "PAL" (yes I know) standards.

>and which people would like to archive now exceeds the expected life of
>all the Betamax heads currently in existence, and it would be too hard
>or expensive to rebuild the head making machinery.
>
Will we see a raiding-of-attics-and-sheds like we did for old Doctor Who
(and other) video recordings, this time for machines (even ones that
don't work, provided the heads are OK)!
--
J. P. Gilliver. UMRA: 1960/<1985 MB++G()AL-IS-Ch++(p)Ar@T+H+Sh0!:`)DNAf

"Bother,"saidPoohwhenhisspacebarrefusedtowork.

On 02/01/2024 18:30, J. P. Gilliver wrote:

> Beta might have been the choice, but it was my understanding that they
> created standard video signals (and reasonably low bandwidth at that),
> so presumably they could have been recorded on VHS or V2000 too.
>
Betamax had a sightly better HF response than other systems at the time,
due to a higher speed of the heads across the tape, so the tapes were
easier to decode accurately. Betamax recorders were also better built
than almost all VHS recorders of the period. V2000 was later,and also
had a problem in that the cassette could hold two programmes, depending
on which way up it was, because it only used half the tape width at a
time. It never really caught on, especially as the two major
manufacturers initially made recorders which were not completely
compatible with each other's tapes.

> IIRR, it's also why we have the rather odd sampling rate of 44100 hertz
> - it sort of fell out of the pseudo-video waveform creation, and the
> SECAM and "PAL" (yes I know) standards.
>
It let them use the same crystals for sample timing as for the PAL
colour sub carrier, if I remember correctly. Meant they cost pennies
instead of pounds when the first CD players came out.

> Will we see a raiding-of-attics-and-sheds like we did for old Doctor Who
> (and other) video recordings, this time for machines (even ones that
> don't work, provided the heads are OK)!

Possibly, they are already searching repair shop storerooms for new old
stock heads that never got used to repair machines.

--
Tciao for Now!

John.

In message <kvj53iFd847U1@mid.individual.net> at Tue, 2 Jan 2024
19:05:21, John Williamson <johnwilliamson@btinternet.com> writes
>On 02/01/2024 18:30, J. P. Gilliver wrote:
>
>> Beta might have been the choice, but it was my understanding that they
>> created standard video signals (and reasonably low bandwidth at that),
>> so presumably they could have been recorded on VHS or V2000 too.
>>
>Betamax had a sightly better HF response than other systems at the
>time, due to a higher speed of the heads across the tape, so the tapes
>were easier to decode accurately. Betamax recorders were also better

I _thought_ the pseudo-video was sufficiently undemanding that either
system was quite capable of recording it, though indeed Beta had a
higher bandwidth (IIRR, Beta - and later V2000 - 3 MHz, VHS 2½).

>built than almost all VHS recorders of the period. V2000 was later,and
>also had a problem in that the cassette could hold two programmes,
>depending on which way up it was, because it only used half the tape

I don't see that as a problem - advantage, if anything!

>width at a time. It never really caught on, especially as the two major
>manufacturers initially made recorders which were not completely
>compatible with each other's tapes.

Philips and Grundig? I didn't know that. (If there was any such initial
problem, I think it had disappeared by the time I had the V2000.)
>
>> IIRR, it's also why we have the rather odd sampling rate of 44100 hertz
>> - it sort of fell out of the pseudo-video waveform creation, and the
>> SECAM and "PAL" (yes I know) standards.
>>
>It let them use the same crystals for sample timing as for the PAL
>colour sub carrier, if I remember correctly. Meant they cost pennies
>instead of pounds when the first CD players came out.

Oh, I thought it was because of the two different video standards
(625/25 and 525/30) and the need to find a rate that could be converted
to both of those.
>
>> Will we see a raiding-of-attics-and-sheds like we did for old Doctor Who
>> (and other) video recordings, this time for machines (even ones that
>> don't work, provided the heads are OK)!
>
>Possibly, they are already searching repair shop storerooms for new old
>stock heads that never got used to repair machines.
>
(-:
--
J. P. Gilliver. UMRA: 1960/<1985 MB++G()AL-IS-Ch++(p)Ar@T+H+Sh0!:`)DNAf

"Bother," said the Borg, "we assimilated a Pooh."

On 02/01/2024 19:29, J. P. Gilliver wrote:
> In message <kvj53iFd847U1@mid.individual.net> at Tue, 2 Jan 2024
> 19:05:21, John Williamson <johnwilliamson@btinternet.com> writes

>> built than almost all VHS recorders of the period. V2000 was later,and
>> also had a problem in that the cassette could hold two programmes,
>> depending on which way up it was, because it only used half the tape
>
> I don't see that as a problem - advantage, if anything!
>
Until the studio intern put the tape in downside up and overwrote the
master you wanted to keep.

--
Tciao for Now!

John.

On 02/01/2024 19:05, John Williamson wrote:
> V2000 was later,and also
> had a problem in that the cassette could hold two programmes, depending
> on which way up it was, because it only used half the tape width at a
> time.

I never knew that any of the VCR formats allowed the tape to be turned
over and only used half the track. I've learned something.

I remember turning the tape upside down in a VHS cassette that had a
badly mangled tape in one part and so could never be used in it entirety
and was too much of a risk of the bad bit being played/recorded on by
accident, clogging the heads. So I had a play. I wound the tape all onto
one spool, cut the tape and reattached the empty takeup spool upside
down, then wound the tape completely onto that, and then turned the
now-empty spool upside down. With the reels the correct way up in the
cassette, the tape was now upside down.

And it played! Very noisy picture, monochrome only, motion in reverse,
picture upside down. I was gobsmacked that it worked at all. I suppose
the line-sync pulses now applied to the previous line (the end of one
line becomes the beginning of a neighbouring one.

On 02/01/2024 19:29, J. P. Gilliver wrote:
> In message <kvj53iFd847U1@mid.individual.net> at Tue, 2 Jan 2024
> 19:05:21, John Williamson <johnwilliamson@btinternet.com> writes
>> It let them use the same crystals for sample timing as for the PAL
>> colour sub carrier, if I remember correctly. Meant they cost pennies
>> instead of pounds when the first CD players came out.
>
> Oh, I thought it was because of the two different video standards
> (625/25 and 525/30) and the need to find a rate that could be converted
> to both of those.

Yes I thought it was a frequency that was usable on both TV systems.

I hadn't realised that recording sound digitally on videotape pre-dated
the CD standard and therefore determined the CD sampling rate. I'd
always thought that sound-on-videotape came after CDs.

In article <swSdnUE-ZapP7Qn4nZ2dnZfqn_WdnZ2d@brightview.co.uk>,
NY <me@privacy.net> wrote:
> On 02/01/2024 19:29, J. P. Gilliver wrote:
> > In message <kvj53iFd847U1@mid.individual.net> at Tue, 2 Jan 2024
> > 19:05:21, John Williamson <johnwilliamson@btinternet.com> writes
> >> It let them use the same crystals for sample timing as for the PAL
> >> colour sub carrier, if I remember correctly. Meant they cost pennies
> >> instead of pounds when the first CD players came out.
> >
> > Oh, I thought it was because of the two different video standards
> > (625/25 and 525/30) and the need to find a rate that could be converted
> > to both of those.

> Yes I thought it was a frequency that was usable on both TV systems.

> I hadn't realised that recording sound digitally on videotape pre-dated
> the CD standard and therefore determined the CD sampling rate. I'd
> always thought that sound-on-videotape came after CDs.

Certianly BBC Radio Outside Broadcasts used Beta for recording. After a
number of recording failures, they learned not to smoke over the machine!

--
from KT24 in Surrey, England - sent from my RISC OS 4té²
"I'd rather die of exhaustion than die of boredom" Thomas Carlyle

In message <swSdnUE-ZapP7Qn4nZ2dnZfqn_WdnZ2d@brightview.co.uk> at Tue, 2
Jan 2024 20:23:46, NY <me@privacy.net> writes
>On 02/01/2024 19:29, J. P. Gilliver wrote:
>> In message <kvj53iFd847U1@mid.individual.net> at Tue, 2 Jan 2024
>>19:05:21, John Williamson <johnwilliamson@btinternet.com> writes
>>> It let them use the same crystals for sample timing as for the PAL
>>>colour sub carrier, if I remember correctly. Meant they cost pennies
>>>instead of pounds when the first CD players came out.
>> Oh, I thought it was because of the two different video standards
>>(625/25 and 525/30) and the need to find a rate that could be
>>converted to both of those.
>
>Yes I thought it was a frequency that was usable on both TV systems.
>
>I hadn't realised that recording sound digitally on videotape pre-dated
>the CD standard and therefore determined the CD sampling rate. I'd
>always thought that sound-on-videotape came after CDs.

There was an excellent series - ran over about 26 months, I think - in
Wireless World, that explained everything about the Compact Disc system,
in a manner I found both interesting and comprehensible.
--
J. P. Gilliver. UMRA: 1960/<1985 MB++G()AL-IS-Ch++(p)Ar@T+H+Sh0!:`)DNAf

After all is said and done, usually more is said.

In message <swSdnUY-Zapm8gn4nZ2dnZfqn_WdnZ2d@brightview.co.uk> at Tue, 2
Jan 2024 20:20:11, NY <me@privacy.net> writes
>On 02/01/2024 19:05, John Williamson wrote:
>> V2000 was later,and also had a problem in that the cassette could
>>hold two programmes, depending on which way up it was, because it
>>only used half the tape width at a time.
>
>I never knew that any of the VCR formats allowed the tape to be turned
>over and only used half the track. I've learned something.

The V2000 cassette looked a bit like a giant audio cassette!

It was the only (domestic) format that had dynamic track following - the
heads were mounted on little piezoelectric mounts, and the system
included extra carrier tones, the differences between successive tracks
being picked up and used in servo loops to keep the heads on track -
from the start; I presume that was made necessary by it only using half
the tape width (the tape was about the same width as Beta and VHS),
though it also had the effect of making the system have excellent
tracking ability - a machine in good condition could play at still frame
or at a range of speeds other than just nominal, without even colour
loss, let alone no noise bars. I believe the VHS format may have gained
DTF towards the end of its (and thus towards the end of home VCRs in
general) reign.
>
>I remember turning the tape upside down in a VHS cassette that had a
>badly mangled tape in one part and so could never be used in it
>entirety and was too much of a risk of the bad bit being
>played/recorded on by accident, clogging the heads. So I had a play. I
>wound the tape all onto one spool, cut the tape and reattached the
>empty takeup spool upside down, then wound the tape completely onto
>that, and then turned the now-empty spool upside down. With the reels
>the correct way up in the cassette, the tape was now upside down.
>
>And it played! Very noisy picture, monochrome only, motion in reverse,
>picture upside down. I was gobsmacked that it worked at all. I suppose
>the line-sync pulses now applied to the previous line (the end of one
>line becomes the beginning of a neighbouring one.
>
I had a Philips reel-to-reel VTR, and once experimented; as I'd
expected, it did indeed produce an upside-down backwards picture. I
don't remember it being noisy, and the machine was monochrome only: IIRR
the picture was very jumpy, I presumed because it didn't have the
control track (that machine used IIRR audio and cue track on opposite
edges of the tape).

(Actually, I've still got a couple of the machines: non-functional.
Anyone interested [I'm in mid-Kent]? They look rather like the domestic
audio machines of the era - piano-key controls, knobs for audio and
video level with meters.)
--
J. P. Gilliver. UMRA: 1960/<1985 MB++G()AL-IS-Ch++(p)Ar@T+H+Sh0!:`)DNAf

After all is said and done, usually more is said.

On Sun Dec 24 20:10:32 2023 "NY" wrote:
> I was watching a never-previously-broadcast *colour* version of Last Night
> at the Sunday Palladium (shown a year so ago on Talking Pictures TV), made
> as an experiment before PAL broadcasts began. As far as I could tell, it had
> not been film-recorded.
>
> That led me to think... if it had been originally recorded on 2" Quad tape,
> would that tape still be playable today (assuming it had been stored in
> ideal conditions)? I imagine at some stage it was converted from analogue
> video to a modern digital video format for broadcast by TPTV, but would Quad
> VT last long enough to do that during the time that digital formats have
> been used, or would it have been copied to another more recent analogue
> format (one of the 1" or 3/4" formats) some time in the past before the Quad
> tape deteriorated?
>

Yes, CSC has been recovered from the dot patterns on FR material (provided that it wasn't suppressed on recording).

The problem isn't that early Quad tapes won't be playable, it's that there may be no heads with which to recover them.

On Tue Jan 2 20:23:46 2024 NY wrote:
> On 02/01/2024 19:29, J. P. Gilliver wrote:
> > In message <kvj53iFd847U1@mid.individual.net> at Tue, 2 Jan 2024
> > 19:05:21, John Williamson <johnwilliamson@btinternet.com> writes
> >> It let them use the same crystals for sample timing as for the PAL
> >> colour sub carrier, if I remember correctly. Meant they cost pennies
> >> instead of pounds when the first CD players came out.
> >
> > Oh, I thought it was because of the two different video standards
> > (625/25 and 525/30) and the need to find a rate that could be converted
> > to both of those.
>
> Yes I thought it was a frequency that was usable on both TV systems.
>
> I hadn't realised that recording sound digitally on videotape pre-dated
> the CD standard and therefore determined the CD sampling rate. I'd
> always thought that sound-on-videotape came after CDs.

The length of early CD's appears to be dictated by the longest U-Matic available, which was 74 minutes and made by BASF

On 05/01/2024 17:01, Bill Posters wrote:
> The length of early CD's appears to be dictated by the longest U-Matic available, which was 74 minutes and made by BASF

I thought that apocryphally it was based on a requirement by someone who
influenced the spec, that the whole of a certain orchestral symphony had
to fit on one disc.

On 05/01/2024 17:06, NY wrote:
> On 05/01/2024 17:01, Bill Posters wrote:
>> The length of early CD's appears to be dictated by the longest U-Matic
>> available, which was 74 minutes and made by BASF

> I thought that apocryphally it was based on a requirement by someone who
> influenced the spec, that the whole of a certain orchestral symphony had
> to fit on one disc.

I think it was Beethoven's Ninth.

(It might as well be The Who's Tommy, the double album of which will
just about fit on a single 5" CD.)

--
Max Demian