Prestel was the brand name of a videotex service launched in the UK in 1979 by Post Office Telecommunications, a division of the British Post Office. the Royal Mail issued two commemorative stamps, one of which featured a Prestel TV set and keyboard.

In April 1984, British Telecom won a Queen's Award for Technological Achievement for the development of Prestel.

History

Invention and development

In 1970, Samuel Fedida, a research engineer who had worked at English Electric and a US consultancy company, joined the Post Office as head of the Computer Applications Research Division. Within a year, he had completed the initial design of a viewdata system (the generic term in use at the time) for the general public: it would comprise information stored on a central computer accessed over the public phone network using modified televisions as terminals. By early 1973, the Post Office had decided to develop an experimental system, and was working with the BBC, the Independent Broadcasting Authority, and standards organisations to develop compatible standards for teletext and viewdata. During 1974, it decided to commercialise the viewdata concept. where Fedida presented a paper on the technology and the potential appeal, as the Post Office saw it, of a public interactive information service.

Further demonstrations followed, and based on the favourable reactions of TV manufacturers and potential providers of information and services, the Post Office decided to run a pilot trial.

The two-year pilot service began in January 1976. Interviewed by The Times, Fedida was quoted as saying that the Post Office saw viewdata playing several roles: as a "centralised information source", an "intelligent interface" to specialised scientific and technical data, a "communication machine" for passing messages, a personal information store, a new information distribution medium, a "channel for education in the home", and as providing an "advanced calculator service". the Post Office launched a test service of Prestel, as it was now called, in October 1978. At the end of December, there were 95,500 information pages, growing at a rate of 3,500 per week, and just over 300 users, increasing by 3050 per week.

By February 1980, there were 131 IPs and 116 sub-IPs. The Post Office categorised the IPs as follows: national and local newspaper groups; magazine and other publishing groups; central government departments, and other agencies (such as the British Tourist Authority and the British Library); nationalised industries (including British Airways, Sealink, and British Rail), and companies in other fields of business, such as banks and travel agencies; new companies set up to exploit the viewdata medium, and those expanding from an existing base of online services, such as Reuters; associations; software companies; and miscellaneous. and the Consumers' Association. Overall, popular topics included games, quizzes, jokes, and horoscopes; the Stock Market, company information, and business news; travel and holiday information; national news, sports, and "What's On" locally; cars; and consumer advice.

Writing in the winter 1980/81 issue of British Telecom Journal, Prestel's public relations manager stated there were over 7,500 sets attached to the system, 170,000 frames in use, and more than 400 IPs and sub-IPs. By the end of 1981, according to Butler Cox, a management consultancy, Prestel had 2,000 residential and 11,000 business users, with 14,000 "terminals" in use. The service was within local call reach of 62% of phone subscribers in Britain. IPs numbered 153, with 593 sub-IPs. Users accessed 190,000 frames per day, and the average time on the system, for each user per day, was 9 minutes. There were 193,000 frames available, including 2,000 response frames.

Prestel Gateway

March 1982 saw the launch of the Prestel Gateway service. This enabled users to connect, via the Prestel network, to external computers operated by IPs or other companies. Travel agents, for example, used Gateway to connect to tour operators' systems and make reservations.

By October 1982, the online usage charge had risen to 5p per minute (8 am to 6 pm Monday to Friday and also 8 am to 1 pm on Saturdays, free at other times), the business standing charge to £15 per quarter, residential users now paid £5 per quarter, and jack installation cost "from £15", with a 15p quarterly rental fee. under page *656#, Prestel's publicity department published a "Factframe" showing, at the end of each month, the average number of terminals attached and the respective percentages in businesses and in homes; the number of frames available and the number of frame accesses per week; and the number of messages sent per week. Actual subscriber figures were not published; Thomas et al. (1992) suggest these were "significantly less" than the number of terminals, as "businesses were assumed to 'attach' more than one terminal", and note that British Telecom stopped publishing figures at the end of 1988.

In September 1982, The Times reported there were 18,000 users, of whom 3,000 were residential. Noting that British Telecom had originally forecast 50,000 users at this point, the report went on to outline a new approach to attracting them, quoting senior managers from British Telecom and the head of a joint venture. The plans involved the introduction of a home banking service; the marketing of a Prestel adaptor for computer terminals to the business and higher education sectors; and the launch of Micronet 800, a service for microcomputer users.

Six months later, in February 1983, the same newspaper recorded 22,400 users, of whom 15% were residential, writing that the future of Prestel "could be in doubt by 1985 if it is not approaching profitability."

In mid-1984, the UK Department of Trade and Industry issued a booklet stating that the availability of travel information, the launch of Micronet 800, and the provision nationwide of the messaging service, Mailbox, had contributed to a rise to 45,000 attached terminals by June of that year. 61% were in businesses, and 39% in homes. In that month, on average, the Prestel database contained 320,000 frames that were accessed 14.6 million times. 17 Prestel Gateways to external computers were in operation. For July, the Butler Cox consultancy recorded 47,000 users (60% business, 40% residential), and a total of 1,200 IPs and sub-IPs.

In mid-1985, The Times stated there were 53,000 "terminals, adapted televisions, microcomputers or specially designed units" attached to Prestel, with residential users now accounting for 45% of the total. In the reporter's view, this represented "a change of fortune for [a service] deemed commercially dubious by many commentators." The figure of 65,000 was reached at the beginning of 1986about a third were Micronet 800 subscribers. Prestel had reportedly traded at a profit from the previous October onwards. Commenting in September 1986 on what it referred to as "only 70,000 users ... growing at a rate of ... a few hundred customers a week", The Times declared that Prestel "had failed to live up to expectations", comparing it unfavourably to the French Teletel videotex service and to British Telecom's own Telecom Gold electronic mail service. Earlier in the year, The Guardian had also praised Teletel, asking "Can Prestel be improved or should we just scrap it and start again?", and questioning whether a scrolling, text-based system, such as CompuServe's, was in any case preferred by most consumers over page- and graphics-orientated videotex services.

Writing in The Guardian just before Christmas 1988, Jack Schofield reported that Prestel "had become reclusive" about user numbers, with the Factframe, "[a]fter prompting, ... finally updated this summer ... claim[ing] 90,000 users", while the figure of "only 75,000" was being quoted by the British Telecom manager responsible for the service. In January 1989, drawing on what turned out to be the final Factframe, published at the end of 1988, Schofield wrote that "After ten years, [Prestel] has yet to achieve the number of users it expected to get in its first year", quoting a figure of 95,460 terminals attached. Membership had decreased from a peak of around 20,000. The Times agreed, and also pointed to a steep rise in subscription charges, opining that "BT's failure to provide even this committed group with an economic ... service means that Prestel is destined ... for businesses." The closure in April 1991 of Homelink, the home banking service launched in 1983 by the Nottingham Building Society, also contributed to shrinking the number of Prestel subscribers.

Closure

British Telecom closed Prestel in early 1994, selling it to a consortium. It was rebranded as "New Prestel", focusing on the provision of financial data to businesses.

In 1999, the financial data component of Prestel On-line was bought by the company Financial Express to become "Financial Express Prestel". The service component merged with the ISP Demon Internet, which ran a "Prestel Internet Service". This closed in 2002.

In the aftermath of Prestel's pivot away, in the early 1980s, from a focus on the general public to targeting the business community, the professions, and microcomputing enthusiasts,

Noll contrasted the "relative failure" of Prestel with the "success" of teletext, noting that receiving the latter was free and its database much smaller. This latter view was also held by Mosco, a political economist, who wrote in 1982: "[T]he British government appears to be prepared to let Prestel sink or swim on its own commercial ability ... It is too early to offer a complete assessment of Prestel. However, the direction of development is clear: the need for immediate commercial success means cutting back on earlier mass marketing efforts and an emphasis on specific business uses."

In a paper published shortly after Prestel had been discontinued in 1994, Case, an information scientist, examined the motivations behind the development of this and other videotex services from a sociological perspective. In his view, "[E]xplanations of videotex require consideration of higher-level phenomena [such] as policy, ideology, belief, and vision". He identified the envisioning of videotex as a facilitator of mass participation in an emerging information societya belief held and promoted by many politicians, futurists, sociologists, and business leaders in the 1960s and 1970sas a crucial spur to the development of the technology, sustained investment, and the roll-out of services.

Regarding Prestel, Case summarised the problems it faced (as described by a former chief executive) as the lack of a trigger service, low-quality information, complicated charges, competing services, and uncoordinated marketing by IPs, British Telecom, and terminal and adaptor providers. He cited the control over content exercised by IPs and the system operator, British Telecom,

Database

Pages and frames

Numbering

Information on Prestel was held in a database of "pages". Each page corresponded to a screenful of information, and had a unique number up to nine digits long.

A page could have up to 26 sub-pages, with each sub-page labelled with a letter from "a" to "z". A sub-page was called a "frame": the page itself was frame "a". Neither pages nor frames could scroll.

Each IP rented a three-digit number as its master page. For example, the Meteorological Office's was 209, Combined with the follow-on attribute, this provided a way to continue animations that could not fit within the number of characters available in one frame alone.

This follow-on frame attribute was also used for telesoftware, enabling computer programs, such as those for the BBC Micro, to be downloaded from Prestel. The appearance of a character could be changed using a display-attribute code.

In early 1978, at the end of the pilot trial, Post Office Telecommunications commissioned a study of the content and function of Prestel and how these aspects related to the graphic design of Prestel pages. Several graphics designers were consulted (including the designer of Prestel's logo and its index and system pages), along with professional writers, journalists, media specialists, and database managers.

On graphic design, the main conclusions reached were to encourage IPs to use only a few colours on each page; to take into account the variety of TV sets and other terminals in use (colour or monochrome, different screen sizes, a range of serif or sans-serif typefaces); and to accommodate users with poor sight or colour blindness.

On writing for Prestel, the main finding of the study was to never undertake the composition and editing of content without considering the physical and technical limitations of the Prestel page and the overall structure of the information of which it formed a part.

A page could be directly linked to up to ten other pages by specifying, during editing, the number of the page whose content would be displayed when a user pressed a digit from 0 to 9 on their keypad or keyboard.

The content of pages ranged between two poles: at one, a menu listing the topics available and the number to key to reach them, with no, or minimal, further informationreferred to as an "index page"; and at the other, a screenful of information with few, if any, links to other pagesan "information page". According to Rex Winsbury, as experience with the viewdata medium grew, IPs "gave information on all or most pages, simply varying the amount according to the number of routings [links] that have to be given as well." The Post Office, academics, and the media referred to this hierarchical database arrangement as a tree structure or "inverted tree".

thumb|alt=A diagram in the form of an upside-down stylised tree showing links back to the top|upright=1.5|Links back to the main index were the first refinement made

Though simple in theory, in practice this structure could lead a user to a dead end: they might find that how a subject was described in a menu did not match what they saw on the final destination page, or formed only part of what they were looking for, or provided information without the means to look up related material. Going back through the sequence of menu choices (using the *# command) to try another series of links was limited to three steps in all. Laminated card, 6.9 x 11 cm

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There were three basic navigation commands: Micronet 800, an IP, visualised the relationships between its pages in a London Tube-style schematic map as part of a guide for users.

From 1983 to mid-1987, The Prestel Directory, a quarterly magazine, was distributed free to all Prestel users and also available on subscription: it contained a user guide and subject index, a list of IPs and sub-IPs, feature articles, and videotex product news. This was superseded by Connexions, sent to users every two months till May 1988. A directory was also incorporated into the quarterly Prestel Business Directory published by the Financial Times from 1979.

From January 1986, Prestel published Focus magazine on page 123 "to show you the most useful, entertaining and topical pages from the thousands available." It spotlighted news, sport, weather, and entertainment information on a daily basis, and included weekly features.

Information providers

There were two types of information provider (IP): main IPs, and sub-IPs.

Charges

Page rental

A main IP rented pages from the Post Office (initially) or British Telecom (later), and controlled a three-digit master-page in the database. In 1982, this cost an annual £5,500 for a basic package, equivalent to around £29,000 in 2021.

The basic package included 100 frames; the ability to enter and amend information, retrieve response frames, and store 10 completed response frames; staff training in editing (a two-day seminar), and a copy of the IP editing manual; and, if required, bulk update facilities and an annual print-out of frames in use. Additional frames were available, in batches of 500, for £500 a year (over £2,600 in 2021), A main IP could rent out pages at the market rate. Such IPs were known as "umbrella" IPs. Sub-IPs paid a per-minute charge for editing online: in 1982, this was 8p per minute from Monday to Friday between 8 am and 6 pm, and 8p per four-minute block at all other times Other factors to be taken into account included the traffic pattern (i.e., the expected volume and frequency of data flows), the response time required (as perceived by a user), the size of the database to be accessed, and the changeability of the information stored.

In 1985, British Telecom estimated that for an IP using a typical minicomputer (such as the PDP-11) located 100 km from London and handling up to 10 users simultaneously at peak times, the one-off software set-up cost would be at least £16,000, communication costs would range from £4,280 to £5,550 a year (depending on the type of connection), and Prestel usage would cost £8,600 a year.

An analysis in 1981 of the pros and cons of using an umbrella IP to publish information on Prestel concluded that if the owner of the information needed less than 500 frames, it would be cheaper to use an umbrella IP, but if over 5000, this would be more expensive than doing it themselves. In between these two figures, speed, convenience, and the need for design skills favoured using an IP, while going it alone assured confidentiality and provided more control.

Editing pages

thumb|Cherry Editing Keyboard manufactured by [[Cherry_AG|Cherry GmbH, connected to a Deccafax Viewdata Terminal Model VP1 manufactured (19791994) by Decca Radio & Television. Keyboard 11 x 50 x 31 cm, terminal 42 x 45 x 45 cm, 28 kg]]There were two ways to edit pages: directly, by creating or amending them using special editing keyboards while connected online to the main Update Computer; or offline, creating pages locally and uploading them in bulk. Bulk update required that pages be created offline using editing terminals that could store pages, or by using microcomputers. The pages were then either transmitted to the Update Computer online as a batch via a special dialup port and protocol, or sent on magnetic tape to the Update Centre (UDC), where they were uploaded. When the service launched in late 1979, Post Office Telecommunications had a hands-off approach towards managing whatever IPs placed on the system. <!--Prestel did not attract many users.-->This changed in early 1980, when British Telecom (its successor) started targeting the business, professional and hobbyist markets via joint ventures with companies and organisations with specialised expertise.

  • British Telecom Travel Service provided travel agents with information from tour operators, airlines, and other transport operators, and enabled online reservations. Services for other users included flight arrivals and departures, car rental, and exchange rates.
  • Prestel Farmlink packaged information for farmers from the Ministry of Agriculture, Fisheries and Food, the Meat and Livestock Commission, the Meteorological Office, and others. A link to Prestel CitiService provided farm commodity prices, and farmers could calculate, online, weekly wages and the formulation of feedstuffs.
  • Banking: the Nottingham Building Society offered Homelink, and the Bank of Scotland HOBS, the Home & Office Banking Service. Subscribers were provided with free or subsidised Prestel terminals.
  • Prestel Microcomputing offered downloadable software (telesoftware), noticeboards, newsletters, and reviews. It incorporated Micronet 800 from EMAP, Viewfax 258, and Clubspot 810.
  • Prestel Education targeted schools and colleges, and provided course and careers advice, educational software, and help with using computers.
  • British Telecom Insurance Services provided financial information to insurance intermediaries and enabled them to get online quotes from major insurance companies.
  • Prestel Teleshopping was a specialised e-commerce service for the residential market, and involved Littlewoods, Grattan, and Kays Catalogues, among others.
  • Prestel for Medical Practitioners packaged material from bodies such as the Royal College of General Practitioners, the British Medical Association, and the Department of Health and Social Security with drug data from pharmaceutical companies, information on locum vacancies, conference and training diaries, and research news. The user's name and other information needed (such as their address) were automatically added to the frame from their Prestel account details.

Initially, response frames had to be collected by an IP from each IRC in turn; later, they were ingathered at the UDC, where the IP concerned could retrieve them. Eventually, with the introduction of Mailbox, response frames could be retrieved from any IRC.

Mailbox

thumb|Launch version of Prestel Mailbox entry page, *7# (1981)

Prestel Mailbox was launched in September 1981. Initially hosted on a computer in London, it was made available UK-wide in September 1984.

The entry page was *7#. This linked to pages where messages could be composed, stored messages retrieved, and standard, pre-formatted messages completedmany designs were available, including greetings cards, invitations, and seasonal messages such as valentines.

To prepare a basic message, a blank message page (*77#) was displayed, with the sender's Mailbox number pre-filled and blank fields for entering the recipient's number and the message text. There was space for about 100 words, and fewer if graphics were used. After addressing (with a Mailbox number) and writing the message, the user was offered the choice of keying 1 to send, or 2 to not send. Successful dispatch led to a confirmation page; if there were problems, such as a mistake in entering the recipient's number, an error message was displayed. Sending a message to more than one recipient meant re-keying the text into a new message page, although some microcomputers allowed the original message to be stored and then copy-pasted.]]

Mailbox numbers were derived from the last nine digits of a user's phone number. For example, the Mailbox number for Prestel HQ, with the phone number 01-822-2211, was 018222211. Numbers were listed on page *486#. Ex-directory numbers were available on request.

thumb|Prestel Mailbox promotional badge, 1983. Metal, 5.6 cm diameterWhen a user connected to Prestel, a banner on their Welcome page alerted them to any new messages, and when signing off via *90#, a warning would appear if any new messages had arrived in the meantime, with the option to read them before disconnecting. Messages were retrieved from page *930#, where they were presented in chronological order. After reading a new message, a user had to choose between deleting or saving it before the next message was presented. Three messages could be stored at a time, and were accessible via page *931#.

Using this first version of Prestel Mailbox was free of additional charges.

Simpatico

thumb|Simpatico entry page (1985).

Simpatico was a free small ads service run by Prestel on page *787#. Users sent in their ads on a preformatted Mailbox page, with responses made via Mailbox. Ads were vetted and grouped under the headings of Heartsearch, Penpals, Interests & Hobbies, Meetings, Groups & Events, Friendsy (for younger users), and Life Begins At...

Prestel Mailbox was extended in September 1984 to give access to the UK Telex service via "Telex Link". On *8#, the Telex Link entry page, a message could be composed and the telex number entered before sending the telex like a standard message. Telex Link added the necessary telex codes and tried to send the message several times before confirming receipt (or failure) via Mailbox.

In September 1985, the service was enhanced to enable telexes to be sent to and received from anywhere in the world. A telex could be sent to a Mailbox user from any telex terminal by using 295141 TXLINK G, the Telex Link number, as the telex address, and entering "MBX", followed by the Prestel user's Mailbox number, as the first line of the telex. An incoming telex appeared to the Prestel recipient as an ordinary Mailbox message, with the telex number of the sender added at the top of the screen.

Sending a telex cost 50p for UK destinations, £1.00 for Europe, £2.00 for North America, £3.00 for elsewhere in the world, and £5.00 for sending to ships (via INMARSAT). There was no charge for receiving one.

Telex Link was upgraded in 1987, with connections to more telex lines and faster delivery times, and its address changed to 934999 TXLINK G.

Mailbox upgrade

A new messaging system was introduced in July 1989. This enabled messages up to five frames long, storing messages before sending, sending to multiple recipients (either individually or via a mailing list), message forwarding, and acknowledgment of receipt. Basic word-processing was also possible.

Sending a message without using any of these new facilities remained free: all the new options were charged at 1p per use per recipient. For the first time, sending spam was permitted at a cost of 20p per message per recipient. In addition, the stored message facility was replaced by a summary page listing all the messages, both new and old, that were waiting: the user could then pick which message to view, rather than needing to read through them in chronological order.

Message statistics

Nearly two years after the introduction of Mailbox in autumn 1981 on a computer in London, Prestel stated that a total of Mailbox messages had been sent. By early 1984, users were exchanging emails at the rate of about 61,000 per month and sending an additional 125,000 response frames to IPs. 71,000 monthly emails were recorded soon after, This average weekly figure rose to 130,000 in December 1985.

Hack

A security breach of the Prestel mailbox of Prince Philip, Duke of Edinburgh occurred in November 1984 as part of a wider hack of Prestel.

Infrastructure

Terminals

During the development phase of Prestel, British Telecom's research department produced a Prestel terminal specification. This formed the basis of design and type-approval discussions with, initially, manufacturers of TVs, and later with suppliers of other forms of terminal.

Several types of Prestel terminal were produced:

When the full commercial service launched in September 1979, three new computer centres were opened in London. This network handled about 2,000 Prestel terminals and provided users with over 160,000 pages supplied by around 130 IPs. By mid-1981, this arrangement had been replaced by dedicated X.25 circuits using the then-new PSS packet-switched network and operating at 4.8&nbsp;kbit/s. Each IRC typically housed two information retrieval computers, though some in London had a single machine. IRCs were usually located in telephone exchanges.

These ten computers could initially connect to around 1000 user ports, expandable to 2000.

Mailbox computer

Mailbox, the Prestel messaging service, was launched on Enterprise computer, and allowed messaging only between users accessing that machine. By 1984, Mailbox had been rolled out nationwide using a dedicated computer in London known as Pandora.

The commercial service had several important additional functions, including an editing program and bulk update facilities, closed user groups, messages, user billing and IP revenue allocation, optional additional user passwords, error-reporting routines, system manager facilities, and statistics-collecting routines.

International sales

Prestel software and knowhow was sold to the state PTTs of several countries, including Austria, Australia, former West Germany, the then-British colony of Hong Kong, Malaysia, the Netherlands, and Switzerland.