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Inspector Sands13,255 posts since 25 Aug 2004
Some very good points made can I offer some more information – sorry it’s long!

Don't apologise, long but definitely worth it. Interesting slide presentation, I had some idea how Teletext (the ITV and C4 service) worked and was distributed (I had an interesting pack from them which I gave to someone for uploading and never saw again, wish I'd kept it and scanned it) but not Ceefax. I hadn't realised that the other services on the BBCs VBI were all effectively combined into Ceefax.
Riaz561 posts since 6 Jan 2016
It failed mainly because of the fragmented nature of American TV. They didn't have a duopoly of to broadcasters who could decide and develop a universal system and then roll it out across their channels.


An effort was made by the FCC to come up with a standard, but as I understand it, while the TV manufacturers and most US broadcasters wanted to adopt the BBC/IBA standard, a few -including CBS- felt the French system was far superior.


Not quite.

The CBS lobbied the FCC to make the French Antiope system the standard teletext protocol for the US but later abandoned the system in the mid 1980s in favour of NABTS. Antiope enabled TVs stopped being manufactured in 1987 and Antiope broadcasts ended in France in the early 1990s after France adopted the British teletext standard.

A competing system to both Antiope and the British teletext standard developed in Canada was NABTS (North American Broadcast Teletext Specification) that was adopted by both NBC and CBS but it failed due to the high cost of the separate decoders that were generally only sold in a small number of localities where TV companies operated NABTS services. NBC discontinued NABTS in 1985 and CBS followed a year later. Despite the lack of commercial success of NABTS in the 1980s, decoders were included in analogue TV tuner cards for PCs manufactured in the late 1990s and 2000s.

Following the failures of both Antiope and NABTS in the US, Zenith tried to create a US teletext standard in 1986 by including a teletext decoder module using the (then firmly established in many countries using PAL) British teletext standard in the Digital System 3 sets. A limited number of TV channels made use of these teletext decoders, the most prominent example was the Electra service on the cable channel WTBS, but by then the major national TV companies like NBC and CBS had given up on teletext. Rather strangely, no Japanese TV manufacturers sold any TVs with integrated teletext decoders. This could well have been a major factor why few TV companies decided to operate teletext services.

Competing with teletext for VBI lines was the National Captioning Institute which was established in 1979 several millions dollars of start-up funding from the Federal government and the support of the US Department of Health, Education, and Welfare. The technology behind closed captioning was developed in the US during the 1970s. In 1980 NBC and PBS started including closed captioning to their programmes but CBS decided to offer captioning using Antiope instead. Originally a set-top box (manufactured by Sanyo and sold through the NCI) was required to receive closed captioning as no TVs included a closed captioning decoder as standard. Sanyo determined in the late 1980s that it would be less expensive for the public to buy a TV with an integrated closed captioning decoder rather than a set-top box. The result was that Sanyo lobbied Congress, with the backing of an expert witness testimony, to pass legislation requiring all TVs to be sold with a closed captioning decoder as standard. The Television Decoder Circuitry Act became law in 1990 and gave the FCC powers to enact rules on the implementation of closed captioning decoders in TVs. The FCC mandated that all TVs with a screen size of at least 13 inches manufactured after 1 July 1993 must include a closed captioning decoder as standard.

In 1990, the Americans with Disabilities Act became law and required that TV programmes included subtitles for deaf people although it did not specify that closed captioning should be used rather than teletext.

Zenith decided that it would not be practical to redesign their TVs to have both a teletext decoder and a closed captioning decoder so decided to eliminate the teletext decoder from their 1993 range of TVs. This effectively ended teletext in the US in 1993 and the Electra service also shut down that year.

There are questions whether the disability movements in the US and the US Department of Health, Education, and Welfare were aware of teletext and that it could be used for subtitling programmes (as it was in the UK and Europe) as an alternative to closed captioning. Between 1986 and 1993 both teletext and closed captioning existed in parallel to each other in the US. Did Zenith and teletext service providers ever respond to the lobbying by Sanyo to Congress for closed captioning decoders to be included in TVs as standard, that teletext can also provide subtitling so teletext decoders should be included as standard instead? One could argue that the fragmented nature of American TV and the failure to come up with a teletext standard before 1986 were significant factors hindering the deployment and uptake of teletext services in the US but they were not ultimately responsible for its failure (to even catch on?). Would history have been different if at least one of the major TV networks had decided to offer teletext services nationally after 1986 using the British teletext standard as used with Zenith TVs? Would history have been different if Japanese manufacturers had included integrated teletext decoders on their mid to high end models after 1986 even if initially very few TV companies offered a teletext service? Was teletext ultimately killed off in the US by the disability movements in conjunction with Sanyo who were backing closed captioning instead?
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WW Update gave kudos
noggin14,158 posts since 26 Jun 2001
One of the benefits of the US Closed Caption system, for subtitles, over the NTSC-variant of World System Teletext, was that it was a much lower data rate signal which was thus more robust. As a result it survived VHS recording, and mastering, so off-air recordings and pre-recorded movie cassettes could carry Closed Captions, whereas teletext didn't really survive VHS (*) recording.

This was why there were also 'PAL' closed caption decoders sold in the UK to allow movie VHS tapes to be watched with optional subtitles.

(*) Yes - I'm aware that you can extract WST data from VHS recordings, but to do so relies on the cyclic nature of teletext transmission giving you multiple datasets to reduce errors.
1
WW Update gave kudos
Riaz561 posts since 6 Jan 2016
One of the benefits of the US Closed Caption system, for subtitles, over the NTSC-variant of World System Teletext, was that it was a much lower data rate signal which was thus more robust. As a result it survived VHS recording, and mastering, so off-air recordings and pre-recorded movie cassettes could carry Closed Captions, whereas teletext didn't really survive VHS (*) recording.

This was why there were also 'PAL' closed caption decoders sold in the UK to allow movie VHS tapes to be watched with optional subtitles.

(*) Yes - I'm aware that you can extract WST data from VHS recordings, but to do so relies on the cyclic nature of teletext transmission giving you multiple datasets to reduce errors.


This is true although I'm unsure whether it was a deciding factor in the US towards passing the Television Decoder Circuitry Act requiring closed captioning decoders instead of teletext decoders.

S-VHS successfully records teletext, including subtitles, but it failed to catch on.
Neil Jones4,995 posts since 23 Dec 2001
Central (West) Midlands Today
I think its only been relatively recently it became possible to record teletext from Standard Play VHS recordings. Previously it was only the preserve of recordings made on SVHS and possibly Betamax (maybe even Video 2000?) where it was possible with enough time and effort.

VHS Long Play (and where appropriate, EP mode, Extended Play which wasn't an official standard and depended entirely on the model of the unit to support it) would degrade the picture quality over SP and presumably the lines that Teletext was carried on but I suppose it didn't really matter as such as it wasn't meant to be used that way, the fact it survived on recordings at all may have been a quirk of the system.

I used to have a Teletext TV that could "see" the teletext on VHS recordings but if you bought it up it looked like an explosion in a Lego factory. It never improved no matter how long you left it up and what was rendered was different every time. But as I say it wasn't meant for that anyway.
Whataday9,700 posts since 13 Sep 2001
HTV Wales Wales Today
I think its only been relatively recently it became possible to record teletext from Standard Play VHS recordings. Previously it was only the preserve of recordings made on SVHS and possibly Betamax (maybe even Video 2000?) where it was possible with enough time and effort.


I think I was able to record a pretty decent teletext picture using a four head VCR.
Riaz561 posts since 6 Jan 2016

The commercial success of Oracle / Teletext ltd (and why not USA)
If it had been just advertising – I don’t think it would have been so successful – and it was the lack of understanding of the need for his more “public service” material that the Americans could not get their mind around (or threat to local print media)


I don't know what I think matters, but what should have been on there was what ended up on there - a PSB teletext service.


There may be some truth that Americans struggled to comprehend the utility of teletext for PSB material, but as I have not looked at American teletext pages in detail then I can't really comment on this.

On the other hand, there is no reason to suggest that teletext cannot be used to convey light hearted or entertaining material rather than PSB or reference type material. Tales about exploring haunted houses may be frivolous entertainment but it could potentially attract large audiences to teletext who would not otherwise be interested if all it broadcast was useful but boring reference material.

Would it have been better if Ceefax firmly positioned itself as the PSB teletext service but the replacement for Oracle had much more entertaining and light hearted material? Could this have been the key to making teletext work in the fragmented American TV market if the major national TV companies had given up on teletext services?

Technologist mentions the print media. How exactly did the very different nature of print media in the UK vs the US have an impact on teletext services in both countries?
Markymark6,381 posts since 13 Dec 2004
Meridian (North) South Today
I think its only been relatively recently it became possible to record teletext from Standard Play VHS recordings. Previously it was only the preserve of recordings made on SVHS and possibly Betamax (maybe even Video 2000?) where it was possible with enough time and effort.


I think I was able to record a pretty decent teletext picture using a four head VCR.


Part of the key to success was where the head switching point was. Obviously it had to be in the VBI, but in some cases it wasn’t on the teletext data lines