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Videotex (or "interactive videotex") was one of the earliest implementations of an "end-user information system". From the late 1970s to mid-1980s, it was used to deliver information (usually pages of text) to a user in computer-like format, typically to be displayed on a television.
In a strict definition, videotex refers to systems that provide interactive content and display it on a television, typically using modems to send data in both directions. A close relative is teletext, which sends data in one direction only, typically encoded in a television signal. Sometimes the term "viewdata" is used to describe all such systems generically. Unlike the modern Internet, all traditional videotex services were highly centralized.
Videotex in its broader definition can be used to refer to any such service, including the Internet, bulletin board systems, online service providers, and even the arrival/departure displays at an airport. This usage is no longer common.
The first attempts at a general-purpose videotex service were created in the United Kingdom in the late 1960s. In about 1970 the BBC had a brainstorming session in which it was decided to start researching ways to send closed captioning information to audience. As the Teledata research continued the BBC became interested in using the system for delivering any sort of information, not just closed captioning. In 1972, the concept was first made public under the new name Ceefax. Meanwhile the General Post Office (soon to become British Telecom) had been researching a similar concept since the late 1960s, known as Viewdata. Unlike Ceefax which was a one-way service carried in the existing TV signal, Viewdata was a two-way system using telephones. Since the Post Office owned the telephones, this was considered to be an excellent way to drive more customers to use the phones. Not to be outdone by the BBC, they also announced their service, under the name Prestel. ITV soon joined the fray with a Ceefax-clone known as ORACLE.
In 1974 all the services agreed a standard for displaying the information. The display would be a simple 40x24 grid of text, with some "graphics characters" for constructing simple graphics. This standard was called CEPT1. The standard did not define the delivery system, so both Viewdata-like and Teledata-like services could at least share the TV-side hardware (which at that point in time was quite expensive). The standard also introduced a new term that covered all such services, teletext. Ceefax first started operation in 1977 with a limited 30 pages, followed quickly by ORACLE and then Prestel in 1979.
Prestel was somewhat popular for a time, but never gained anywhere near the popularity of Ceefax. This may have been due primarily to the relatively low penetration of suitable hardware in British homes, requiring the user to pay for the terminal (today referred to as a set-top box), a monthly charge for the service, and phone bills on top of that (unlike the US, local calls were paid for in most of Europe at that time). In the late 1980s the system was re-focused as a provider of financial data, and eventually bought out by the Financial Times in 1994. It continues today in name only, as FT's information service. A closed access videotex system based on the Prestel model was developed by the travel industry, and continues to be almost universally used by travel agents throughout the country.
Using a prototype domestic television equipped with the Prestel chip set, Michael Aldrich of Redifon Computers Ltd demonstrated real-time transaction processing in 1979 and thus invented teleshopping or online shopping as it is now called. From 1980 onwards he designed, sold and installed systems with major UK companies including the world's first travel industry system,the world's first vehicle locator system for one of the world's largest auto manufacturers and the world's first supermarket system.He wrote a book about his ideas and systems which among other topics explored a future of teleshopping and teleworking that has proven to be prophetic. Before the IBM PC, Microsoft and the Internet, he invented and manufactured and sold the 'Teleputer', a PC that could receive TV programmes and communicate using its Prestel chip set.
The Teleputer was a range of computers that were suffixed with a number. Only the Teleputer 1 and Teleputer 3 were manufactured and sold. The teleputer 1 was a very simple device and only worked as a teletex terminal, whereas the Teleputer 3 was a z80 based micro computer. It ran with a pair of single sided 5 1/4 inch floppy disk drive; a 20Mb Hard disk drive version was available towards the end of the product's life. The operating system was CP/M or a proprietary variant CP*, and the unit was supplied with a suite of applications, consisting of a word processor, spreadsheet, database and a semi-compiled basic programming language. The display supplied with the unit (both the Teleputer 1 and 3) was a modified Rediffusion 14 inch portable colour television, with the tuner circuitry removed and being driven by a RGB input. The unit had a 64Kb onboard memory which could be expanded to 128Kb with a plug in card. Graphics were the standard videotext (or teletext) resolution and colour, but a high resolution graphic card was also available. A 75/1200 baud modem was fitted as standard (could also run at 300/300 and 1200/1200), and connected to the telephone via an old style round telephone connector. In addition a IEEE interface card could be fitted. On the back of the unit there was a RS232 and Centronic connections and on the front was the connector for the keyboard.
The proposed Teleputer 4 & 5 were planned to have a laser disk attached and would allow the units to control video output on a separate screen.
Interest in the UK trials did not go unnoticed in North America. In Canada the Department of Communications started a lengthy development program in the late 1970s that led to a graphical "second generation" service known as Telidon. Telidon was able to deliver service using the vertical blanking interval of a TV signal or completely by telephone using a Bell 202 style (split baud rate 150/1200) modem. The TV signal was used in a similar fashion to Ceefax, but used more of the available signal (due to differences in the signals between North America and Europe) for a data rate about 1200-bit/s. Some TV signal systems used a low-speed modem on the phone line for menu operation. The resulting system was rolled out in several test studies, all of which were failures.
The use of the 202 model modem, rather than one compatible with the existing DATAPAC dial-up points such as the Bell 212, created severe limitations, as it made use of the nation-wide X.25 packet network essentially out-of-bounds for Telidon-based services. There were also many widely held misperceptions concerning the graphics resolution and colour resolution that slowed business acceptance. Byte magazine once described it as "low resolution", when the coding system was, in fact, capable of 2^24 resolution in 8-byte mode. There was also a pronounced emphasis in government and Telco circles on "hardware decoding" even after very capable PC-based software decoders became readily available. This emphasis on special single-purpose hardware was yet another impediment to the widespread adoption of the system.
Amongst the first services were The Source and CompuServe, both begun in 1979. One of the earliest experiments with marketing videotex to consumers in the U.S. was by Radio Shack, which sold a consumer videotex terminal, essentially a single-purpose predecessor to the TRS-80 Color Computer, in outlets across the country. Sales were anemic. Radio Shack later sold a videotex software and hardware package for the Color Computer.
In an attempt to capitalize on the European experience, a number of US-based media firms started their own videotex systems in the early 1980s. Among them were Knight-Ridder, the Los Angeles Times, and Field Enterprises in Chicago, which launched Keyfax. The Fort Worth Star-Telegram partnered with Radio Shack to launch StarText. (Radio Shack is headquartered in Fort Worth).
Unlike the UK, however, the FCC refused to set a single technical standard, so each provider could choose what it wished. Some selected Telidon (now standardized as NAPLPS) but the majority decided to use slight-modified versions of the Prestel hardware. StarText used proprietary software developed at the Star-Telegram. Rolled out across the country from 1982 to 1984, all of the services quickly died and none, except StarText, remained after another two years. StarText remained in operation until the late 1990s, when it was moved to the web.
The primary problem was that the systems were simply too slow, operating on 300 baud modems connected to large minicomputers. After waiting several seconds for the data to be sent, users then had to scroll up and down to view the articles. Searching and indexing was not provided, so users often had to download long lists of titles before they could download the article itself. Furthermore, most of the same information was available in easy-to-use TV format on the air, or in general reference books at the local library, and didn't tie up your phone line. Unlike the Ceefax system where the signal was available for free in every TV, many U.S. systems cost hundreds of dollars to install, plus monthly fees of $30 or more.
NAPLPS-based services were also being developed by several other joint partnerships between 1983 and 1987. This includes:
- Viewtron, a joint venture of Knight-Ridder and AT&T
- A service in Orange County by a joint venture of Times Mirror and InfoTron
- A service in Toronto by InfoTron
- A service in San Francisco by The Chronicle
- A service in Chicago by News Corp and Ameritech
One of the early videotex providers, Trintex, a joint venture of AT&T-CBS completed a moderately successful trial of videotex use in the homes of Ridgewood, New Jersey. Trintex was merged with another joint venture that added Citibank to the AT&T-CBS partnership. Shortly later Sears bought into the partnership that in circa 1985 began to offer a service called Prodigy, which used NAPLPS to send information to its users, right up until it turned into an Internet service provider in the late 1990s. Because of its relatively late debut, Prodigy was able to skip the intermediate step of persuading American consumers to attach proprietary boxes to their televisions; it was among the earliest proponents of computer-based videotex.
NAPLPS-based systems (Teleguide) were also used for an interactive Mall directory system in various locations including, the Worlds largest indoor mall, West Edmonton Mall (1985) and the Toronto Eaton Center. It was also used for an interactive multipoint audio-graphic educational teleconferencing system (1987) that predated today's shared interactive whiteboard systems such as those used by Blackboard and Desire2Learn.
A private service known as TAARIS (Travel Agents Association Reservation and Information Service) was launched in New Zealand in 1985 for the Travel Agents Association of New Zealand by ICL Computers. This service used ICL's proprietary "Bulletin" software which was based on the Prestel standard but provided many additional facilities such as the ability to run additional software for specific applications. It also supported a proprietary email service.
With the French Minitel system, unlike any other service, the users were given an entire custom designed terminal for free. This was a deliberate move on the part of France Telecom, which reasoned that it would be cheaper in the long run to give away free terminals and teach its customers how to look up telephone listings on the terminal, instead of continuing to print and ship millions of phone books each year.
Once the network was in place, commercial services started to sprout up, becoming very popular in the mid-1980s. By 1990 tens of millions of terminals were in use. Like Prestel, Minitel used an asymmetric modem (1200-bit/s for downloading information to the terminal and 75-bit/s back).
Bell Canada introduced Minitel to Quebec as Alex in 1988, and Ontario two years later. It was available both as a standalone CRT terminal (very similar in design to Apple's eMac) with 1200-bit/s modem, and as software-only for MS DOS computers. The system was received enthusiastically thanks to a free two-month introductory period, but fizzled within two years. Online fees were very high, and the useful services such as home banking, restaurant reservations, and news feeds, that Bell Canada advertised did not materialise; within a very short time the majority of content on Alex was of poor quality or very expensive chat lines. The Alex terminals did double duty for connecting to text-only BBSes.
Minitel in Brazil
A very successful system was started in São Paulo, Brazil, by then state-owned Telesp (Telecomunicações de São Paulo). It operated from 1982 to the mid-nineties; a few other state telephone companies followed Telesp's lead, but each state kept standalone databases and services. The key to its success was that the phone company offered only the service and phone subscriber databases and third parties - banks, database providers, newspapers - offered additional content and services. The system peaked at 70 thousand subscribers around 1995.
The Germans took the CEPT1 concept and expanded it so it was somewhat more flexible, the resulting standard was called CEPT2.
In Germany, the system was named BTX (Bildschirmtext [Engl: "screen text"]).
After that the French went one step further and developed CEPT3 that would be used for their popular Minitel system.
None of the CEPT standards used high resolution graphics.
Comparison to the Internet today
Some people confuse videotex with the Internet. Although early videotex providers in the 1970s encountered many issues similar to those faced by Internet service providers 20 years later, it is important to emphasize that the two technologies evolved separately and reflect fundamentally different assumptions about how to computerize communications.
The Internet in its mature form (after 1990) is highly decentralized in that it is essentially a federation of thousands of service providers whose mutual cooperation makes everything run, more or less. Furthermore, the various hardware and software components of the Internet are designed, manufactured and supported by thousands of different companies. Thus, completing any given task on the Internet, such as retrieving a webpage, relies on the contributions of hundreds of people at a hundred or more distinct companies, each of which may have only very tenuous connections with each other.
In contrast, videotex was always highly centralized (except in the French Minitel service, also including thousands of information providers running their own servers connected to the packet switched network "TRANSPAC"). Even in videotex networks where third-party companies could post their own content and operate special services like forums, a single company usually owned and operated the underlying communications network, developed and deployed the necessary hardware and software, and billed both content providers and users for access.The exception was the transaction processing videotex system developed in the UK by Michael Aldrich(1979) which brought teleshopping [or Online shopping as it was later called] into prominence and was the idea developed later through the Internet. Aldrich's systems were based on minicomputers that could communicate with multiple mainframes. Many systems were installed in the UK including the world's first supermarket teleshopping system. Nearly all books and articles (in English) from videotex's heyday (the late 1970s and early 1980s) seem to reflect a common assumption that in any given videotex system, there would be a single company that would build and operate the network. Although this appears shortsighted in retrospect, it is important to realize that communications had been perceived as a natural monopoly for almost a century — indeed, in much of the world, telephone networks were then and still are explicitly operated as a government monopoly. The Internet as we know it today was still in its infancy in the 1970s, and was mainly operated on telephone lines owned by AT&T which were leased by ARPA. At the time, AT&T did not take seriously the threat posed by packet switching; it actually turned down the opportunity to take over ARPANET. Other computer networks at the time were not really decentralized; for example, the private network Tymnet had central control computers called supervisors which controlled each other in an automatically determined hierarchy. It would take another decade of hard work to transform the Internet from an academic toy into the basis for a modern information utility.
Definitions of Videotex and associated terms  These definitions were written in 1980 so some names may be out of date.
- Videotex The generic term used, but not formally approved (at the end of 1979), by CCITT for a two-way interactive service emphasizing information retrieved, and capable of displaying pages of text and pictorial material on the screens of adapted TVs.
- Viewdata An alternative term to videotex, used in particular by the British Post Office and generally in Britain and the USA. Elsewhere, the term videotex is preferred. Viewdata was coined by the BPO in the early 1970s, but found to be unacceptable as a trade name, hence its use as a generic.
- Teletext A generic term used to describe one-way broadcast information services for displaying pages of text and pictorial material on the screens of adapted TVs. A limited choice of information pages is continuously cycled at the broadcasting station. By means of a keypad, a user can select one page at a time for display from the cycle. The information is transmitted in digital form usually using spare capacity in the broadcast TV signal. Careful design can ensure that there is no interference with the normal TV picture. Alternatively, it can use the full capacity of a dedicated channel. Compared with two-way videotex, teletext is inherently more limited, though generally less costly.
- Teletex A text communication standard for communicating word processors and similar terminals combining the facilities of office typewriters and text editing.
- Ceefax Ceefax ('See facts') is the BBC's name for its public teletext service available on two TV channels using spare capacity.
- Oracle Oracle ('Optional recognition of coded line electronics') is the name of the IBA's equivalent teletext service.
- Bildschirmtext, DataVision, Captain, Teletel, Prestel, Viewtron, etc. The proprietary names for specific videotex implementations.
- Videotex - Key to the Wired City by Michael Aldrich Quiller Press (1982)
- Le Vidéotex by Claire Ancelin et Marie Marchand, ed. Masson (1984) in French
- Télématique, techniques, normes, services, coordinated by Bernard Marti, ed. Dunod (1990) in French
- Joint Ventures in the Cable and Videotex Industry, Masters Thesis by Thomas P. Caruso and Mark R. Harsch, Edward B. Roberts Thesis Supervisor, MIT Sloan School of Management, 1984
- ↑ ‘Videotex takes Gateshead Teleshopping into the home’ ‘The Incorporated Engineer’ Journal of the IEEIE London September 1984, p. 6.
- ↑ Pioneers of Online Shopping, Aldrich Archive, University of Brighton, www.aldricharchive.com
- ↑ Videotex-Key to the Wired City, Aldrich MJ, Quiller Press London 1982
- ↑ Telecom Viatel: Service Provider Information
- ↑ Telecom Viatel: Key facts for Service Providers
- ↑ Videotex - the new television-telephone information services, by R. Woolfe, published by Heyden & Son Ltd, London, 1980, ISBN 0 85501 493 8
- Online service provider
- Nabu Network. The Nabu Network was not a videotex system, but it was an early data communications service which was centrally run by the Canadian cable industry.da:Teledata (teletjeneste)