Prestel#Prestel Gateway

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.{{rp|107{{ndash}}109}}

The first public demonstration of viewdata took place in London in 1975 during Eurocomp, the European Computing Conference on Communications Networks,

{{

cite newspaper The Times

|title=Why the Post Office is so excited by its plans for a TV screen information service

|first=Kenneth

|last=Owen

|department=Business news

|date=26 September 1975

|page=23

|issue=59511

|column=4

|url=https://www.thetimes.com/tto/archive/article/1975-09-26/23/4.html

|quote=Earlier this week the proposed new service was publicly demonstrated for the first time at ... Eurocomp ... at Heathrow. Yesterday the philosophy behind Viewdata was described at the conference by Samuel Fedida [...].

}} where Fedida presented a paper on the technology and the potential appeal, as the Post Office saw it, of a public interactive information service.

{{

cite book

|url=https://archive.org/details/communicationsne0000euro/

|title=Communications Networks: Papers presented at the European Computing Conference on Communications Networks (Eurocomp){{snd}}London, September 1975

|chapter-url=https://archive.org/details/communicationsne0000euro/page/260/mode/2up

|chapter=Viewdata: an interactive information service for the general public

|pages=261{{ndash}}282

|first=Samuel

|last=Fedida

|publisher=Online Conferences Ltd

|location=Uxbridge

|date=1975

|isbn=978-0-903-79605-7

|oclc=2006258

|via=Internet Archive

|url-access=registration

|access-date=28 October 2024

|quote=The concept of Viewdata, a computer-based information medium and service, suitable for non-computer users, is explained by reference to the 'total cost-effectiveness' of computer-based information systems. The means of implementing such a system includes the design of a low-cost, yet of pleasing appearance, rugged and reliable terminal connected to the telephone system, together with its associated keypads, a distributed but interconnected computer system giving access to internal and external databases, a 'natural' protocol for information retrieval requiring no training whatsoever for its effective use and a software structure designed to maximise throughput and hence minimise costs.

|quote-page=261

}}

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.{{rp|110}} It also agreed with potential information providers (IPs) that it would not select IPs or exert editorial control over what they put on the system.

{{

cite book

|editor-first=Rex

|editor-last=Winsbury

|editor-link=Rex Winsbury

|title=Viewdata in Action : a Comparative Study of Prestel

|date=1981

|publisher=McGraw-Hill

|location=London

|first=Alex

|last=Reid

|chapter=Prestel philosophy and practice

|pages=13{{ndash}}28

|chapter-url=https://archive.org/details/viewdatainaction0000unse/page/12/mode/2up

|quote-page=16

|quote=[W]e plumped firmly for the 'common carrier' approach. We rent space in our Prestel computers to anyone who can pay the storage charges. The information providers may choose whether to charge the users to look at their information, and if so, how much; and information providers may put up on their pages whatever information they wish, subject only to the law.

|isbn=978-0-070-84548-0

|oclc=715473323

|url=https://archive.org/details/viewdatainaction0000unse

|url-access=registration

|access-date=5 October 2024

}}

The two-year pilot service began in January 1976.{{rp|111}} By mid-1977, IPs included the Consumers' Association, the British Farm Produce Council, British Rail, London Transport, the Open University, the London Stock Exchange, the Institute for Scientific Information, and National Giro.

{{

cite newspaper The Times

|title=Dial-a-fact television becoming reality

|department=Telecommunications

|date=26 May 1977

|page=17

|issue=60013

|column=1

|url=https://www.thetimes.com/tto/archive/page/1977-05-26/17.html

}}{{rp|cols 3{{ndash}}4}} 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".{{rp|cols 2{{ndash}}3}}

After some delay,{{rp|113}}

{{

cite news

|newspaper=The Guardian

|date=3 October 1978

|title=Prestel's passing problems

|first=Peter

|last=Large

|page=19

|url=https://www.proquest.com/docview/186049881

|id={{ProQuest|186049881}}

}} the Post Office launched a test service of Prestel, as it was now called,{{refn|group=lower-alpha|name=Name}} 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 30{{ndash}}50 per week.{{rp|56}}

{{see also|#Information providers}}

In March 1979, the Post Office opened a limited "London Residential Service" for subscribers in the capital.{{rp|22{{ndash}}23}} The full commercial service launched in September 1979;{{rp|115}} the director of Prestel stated that there were over 130,000 pages in the database and 1363 "sets" connected to the system at the start of that month.

{{

cite news

|newspaper=Guardian

|title=Prestel develops the world's biggest system

|date=13 September 1984

|pages=22{{ndash}}23

|first=Alex

|last=Reid

|url=https://www.proquest.com/docview/186086404/

|url-access=subscription

}}{{rp|23 col 4}}

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.{{rp|100{{ndash}}101}}

Particularly popular were the travel-oriented nationalised industries; new companies, such as Fintel;

{{

cite newspaper The Times

|title=FT and Extel form joint venture

|department=Financial news and market reports

|date=12 January 1978

|page=21

|issue=60208

|column=2

|url=https://www.thetimes.com/tto/archive/article/1978-01-12/21/5.html

}} and the Consumers' Association.

{{

cite book

|editor-first=Rex

|editor-last=Winsbury

|editor-link=Rex Winsbury

|title=Viewdata in Action : a Comparative Study of Prestel

|date=1981

|publisher=McGraw-Hill

|location=London

|first=Ederyn

|last=Williams

|author-link=Ederyn Williams

|chapter=Who's who on the Prestel database

|pages=99{{ndash}}106

|chapter-url=https://archive.org/details/viewdatainaction0000unse/page/99/mode/2up?view=theater

|isbn=978-0-070-84548-0

|oclc=715473323

|url=https://archive.org/details/viewdatainaction0000unse

|url-access=registration

|access-date=29 October 2024

}}{{rp|102}} 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.{{rp|103}} This was reflected in advertisements for Prestel.

{{

cite newspaper The Times

|title=Learn More From Your Telly. Read It

|date=24 March 1980

|issue=60583

|at=p. 3: full-page advertisement showing 21 Prestel pages.

|url=https://www.thetimes.com/tto/archive/page/1980-03-24/3.html

|quote=

}}

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.

{{

cite journal

|journal=British Telecom Journal

|issn=0260-1532

|title=Market review for Prestel

|first=Richard

|last=Hope-Smith

|volume=1

|issue=4

|pages=8{{ndash}}9

|date=1980–1981

|oclc=8560549

}}{{rp|9}} By the end of 1981, according to Butler Cox, a management consultancy,

{{

cite web

|url=https://archivesit.org.uk/wp-content/uploads/2021/09/BCF-RRBT-03-1982-Iss1.pdf

|access-date=1 November 2024

|title=Developments in Videotex

|date=March 1982

|author=Butler Cox

|publisher=Butler Cox & Partners

|location=London

|series=Butler Cox Report Series #27

|website=Archives of IT

|oclc=

}}{{rp|9}} Prestel had 2,000 residential and 11,000 business users, with 14,000 "terminals"{{sic|nolink=y}} 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. {{section link|#Response_frames}}

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.

{{

cite journal

|journal=ASLIB Proceedings

|first=Chris

|last=Horne

|title=Gateway{{snd}}an enhancement of Prestel

|volume=34

|issue=5

|date=1982

|pages=266{{ndash}}270

|doi=10.1108/eb050847

|issn=0001-253X

}} Travel agents, for example, used Gateway to connect to tour operators' systems and make reservations.{{rp|153}}

At the launch of the commercial service in September 1979, and in addition to phone charges, users were charged 3p per minute online to Prestel from 8 am to 6 pm Monday to Friday, and 3p for three minutes at other times. Installing a phone jack-socket cost £13, with a quarterly rental of 50p. Business users paid an additional standing charge (i.e., a flat charge regardless of usage) of £12 per quarter.

{{

cite document

|title=Prestel: A brief guide [for British Telecom staff] to British Telecom [sic] Viewdata Service

|author=Prestel Marketing Duty

|date=c. 1979

|publisher=British Telecom

|location=Bedford

|pages=6{{ndash}}7

|type=pamphlet

}}

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.{{rp|2}}

From September 1986,

{{

cite book

|title=Telematics in Transition: The Development of New Interactive Services in the United Kingdom

|first1=Graham

|last1=Thomas

|first2=Ian

|last2=Miles

|date=1989

|publisher=Longman

|location=Harlow

|isbn=978-0-5820-5595-7

|oclc=22706270

}}{{rp|27}} 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.An example from 1987:

{{

cite document

|type=videotex frame 65659a

|title=Factframe to end of Oct 1987

|date=October 1987

|publisher=Prestel Publicity Department

}}

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.

{{

cite book

|first1=Graham

|last1=Thomas

|first2=Thierry

|last2=Vedel

|first3=Volker

|last3=Schneider

|author-link3=:de:Volker Schneider (Politikwissenschaftler)

|date=1992

|editor-first1=Harry

|editor-last1=Bouwman

|editor-link1=Harry Bouwman

|editor-first2=Mads

|editor-last2=Christoffersen

|editor-link2=dk:Mads Christoffersen

|title=Relaunching Videotex

|publisher=Springer-Science+Business Media

|location=Dordrecht

|pages=15{{ndash}}30

|chapter=Chapter 2: The United Kingdom, France and Germany: Setting the Stage

|url=https://books.google.com/books?id=H5iqCAAAQBAJ&pg=PA18

|doi=10.1007/978-94-011-2520-8_3

|isbn=978-94-011-2520-8

|oclc=7330970413

}}{{rp|18}}

In September 1982, The Times reported there were 18,000 users, of whom 3,000 were residential.

{{

cite newspaper The Times

|title=Prestel plans another offensive

|first=Bill

|last=Johnstone

|department=Computers and Technology

|date=6 September 1982

|page=13

|issue=61330

|column=2

|url=https://www.thetimes.com/tto/archive/article/1982-09-06/13/7.html

}} 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."

{{

cite newspaper The Times

|title=Prestel races to attract business

|first=Bill

|last=Johnstone

|department=Business News

|date=3 February 1983

|page=16

|issue=61447

|column=2

|url=https://www.thetimes.com/tto/archive/article/1983-02-03/16/4.html

}}

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.

{{

cite book

|title=Viewdata in Retail and Distribution

|author=Department of Trade & Industry

|author-link=Department of Trade and Industry (United Kingdom)

|date=1984

|at="Key facts and statistics", p. 8 (unnumbered)

|publisher=IT Division, Department of Trade & Industry

|location=London

|oclc=17676964

|id=British Library shelfmark GPB-4720

}} For July, the Butler Cox consultancy recorded 47,000 users (60% business, 40% residential), and a total of 1,200 IPs and sub-IPs.{{rp|26, Fig. 1.15}}

After another year, 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."

{{

cite newspaper The Times

|title=Households attracted to Prestel

|first=Bill

|last=Johnstone

|department=Home News

|date=3 June 1985

|page=3

|issue=62154

|column=2

|url=https://www.thetimes.com/tto/archive/article/1983-02-03/16/4.html

}} The figure of 65,000 was reached at the beginning of 1986{{snd}}about a third were Micronet 800 subscribers. Prestel had reportedly traded at a profit from the previous October onwards.

{{

cite newspaper The Times

|title=Prestel moves into the black

|first=Matthew

|last=May

|department=Computer Horizons

|date=14 January 1986

|page=28

|issue=62344

|column=4

|quote=Last October Prestel ... announced it had begun to make a profit in its day-to-day operations for the first time in its six-year existence. Only two years ago it was being suggested ... it should be shut down as an expensive mistake.

}} 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 Minitel videotex service and to British Telecom's own Telecom Gold electronic mail service.

{{

cite newspaper The Times

|title=BT aims to link Prestel with Telecom Gold

|first=Jonathan

|last=Miller

|department=Business and Finance

|date=13 September 1986

|page=22

|issue=62562

|column=3

}}

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.

{{

cite news

|newspaper=The Guardian

|date=22 December 1988

|title=Numbers down

|first=Jack

|last=Schofield

|author-link=Jack Schofield (journalist)

|at=p. 27, col 8

|url=https://www.proquest.com/docview/186886612

|id={{ProQuest|186886612}}

}} 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. This was the highest figure claimed during the lifetime of Prestel.{{rp|18}}

In October 1991, British Telecom closed Micronet 800, stating, in a letter to customers, that "With over 10,000 members, Micronet is easily the largest online service in the UK specialising in microcomputing. However, it is still not large enough to enable us to maintain a cost-effective service and provide the extra facilities requested by our customers."

{{

cite web

|url=https://www.viewdata.org.uk/download.php?cat=15_Prestel&file=micronetrip.pdf

|title=Micronet to close from 31st October 1991

|date=27 September 1991

|first1=Sue

|last1=Gilbody

|type=letter

|publisher=BT Tymnet

|archive-url=https://web.archive.org/web/20120506132636/http://www.viewdata.org.uk/download.php?cat=15_Prestel&file=micronetrip.pdf

|archive-date=6 May 2012

}} Membership had decreased from a peak of around 20,000.{{rp|145}} The Guardian attributed this to the introduction by British Telecom of an off-peak Prestel time-charge in mid-1988, discouraging the use of Micronet's popular "Chatline" service.

{{

cite news

|newspaper=The Guardian

|date=31 October 1991

|title=Reaching the end of the line

|first=Mike

|last=Brown

|at=p. 33, col 8

|url=https://www.proquest.com/docview/187285975

|id={{ProQuest|187285975}}

}} 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."

{{

cite newspaper The Times

|title=Hey Prestel! A disappearing act

|first=Matthew

|last=May

|department=Science and Technology

|date=3 October 1991

|page=30

|issue=64141

|column=1

}} The closure in April 1991 of Homelink, the home banking service launched in 1983 by the Nottingham Building Society,

{{

cite journal

|journal=Journal of Retail Banking

|title=Why home banking bombed in Britain

|first=Philip A.

|last=Dover

|volume=15

|issue=4

|date=Winter 1993

|pages=30{{ndash}}38

|id={{Gale|A15141702}}

|issn=0195-2064

}}{{rp|1}} also contributed to shrinking the number of Prestel subscribers.{{rp|146}}

During 1991, Prestel was closed to residential users.{{rp|146}} Towards the end of 1993, it was reported that British Telecom was planning to close Prestel altogether: according to the company, of the around 35,000 subscribers at that point, only some 2,500 used the service regularly.

{{

cite news

|newspaper=The Guardian

|date=13 November 1993

|title=British Telecom poised to close its loss-making Prestel service

|first=Ben

|last=Laurance

|at=p. 38, col 5

|url=https://www.proquest.com/docview/187571026

|id={{ProQuest|187571026}}

}}

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 mid-1996, New Prestel transferred to the Web, becoming the Internet service provider (ISP) "Prestel On-line"

{{

cite news

|newspaper=The Independent

|title=Steps one, two and three{{snd}}hey Prestel!

|first=Alan

|last=Stewart

|date=28 July 1996

|url=https://www.independent.co.uk/life-style/steps-one-two-and-three-hey-prestel-1331077.html

|access-date=14 December 2024

}}

{{

cite web

|url=http://www.prestel.co.uk/online.htm

|archive-url=https://web.archive.org/web/19970208234324/http://www.prestel.co.uk/online.htm

|archive-date=8 February 1997

|title=Prestel HotZone : Follow the Markets with Prestel On-Line!

|website=Prestel On-line Services

|access-date=14 December 2024

}}

In 1999, the financial data component of Prestel On-line was bought by the company Financial Express to become "Financial Express Prestel".

{{

cite web

|url=https://www.campaignlive.co.uk/article/financial-express-buys-prestel-online/120097

|title=Financial Express buys Prestel Online

|date=20 October 1999

|website=Campaign UK

|access-date=14 December 2024

|quote=Online content supplier Financial Express has bought real-time pricing provider Prestel Online from its management team. Following the purchase, FE will change its name to Financial Express Prestel and specialise in supplying data on equities, unit trusts, investment funds and life and pensions funds.

}} The service component merged with the ISP Demon Internet,

{{

cite news

|newspaper=M2 PressWire

|title=Prestel: Demon and Prestel alliance creates new Internet force

|date=13 January 1999

|publisher=Normans Media

|id={{Gale|A53563938}}

|quote=Demon Internet and Prestel On-line today announced the alliance of the two Scottish Telecom companies which will create one of the most competitive offerings in the UK Internet Service Provider (ISP) market.

}} which ran a "Prestel Internet Service". This closed in 2002.{{rp|146 ft 158}}

Writing in early 1979 about the test service that had launched in October 1978, a Post Office executive concluded that:{{blockquote|text= "The strengths of viewdata include its visual attractiveness, its ease of use, low cost and its wide range of applications. Its weaknesses include its small information window, unsophisticated search methods, its limited storage capacity and its lack of computer power for users. How rapidly viewdata will become established, and the exact role it will fulfil, is as yet a matter of speculation."

{{

cite journal

|first=Ederyn

|last=Williams

|author-link=Ederyn Williams

|title=Strengths and Weaknesses of Prestel

|journal=Computer Communications

|date=April 1979

|volume=2

|issue=2

|pages=56{{ndash}}59

|doi=10.1016/0140-3664(79)90121-X

}}}}

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,{{rp|25}} Noll (1985) studied the possible reasons for Prestel's lack of take-up by households. He concluded that the following factors might have been significant: a shortage, at the beginning of the commercial service, of affordable Prestel-adapted TV sets and, later, adaptors; relatively high frame-access and time-based online charges; the large size of the database, and the difficulty of searching it; and the variation in how information providers (IPs) arranged and presented their Prestel pages.

{{

cite journal

|journal=Information & Management

|title=Videotex: anatomy of a failure

|volume=9

|issue=2

|pages=99{{ndash}}109

|date=September 1985

|first=A. Michael

|last=Noll

|author-link=A. Michael Noll

|url=https://www.polyarchives.hosting.nyu.edu/files/original/2c4421f4c8f7ba4b61518599f648ebdc.pdf

|access-date=17 February 2025

|archive-url=https://web.archive.org/web/20250216211636/https://www.polyarchives.hosting.nyu.edu/files/original/2c4421f4c8f7ba4b61518599f648ebdc.pdf

|archive-date=16 February 2025

|doi=10.1016/0378-7206(85)90031-X

|issn=0378-7206

|oclc=38995112

}}{{rp|99{{ndash}}100}}

Noll contrasted the "relative failure" of Prestel with the "success" of teletext, noting that receiving the latter was free and its database much smaller.{{rp|101{{ndash}}102}} Overall, he questioned "the [...] hypothesis that the information needs of consumers can be satisfied by a large, centralized, computerized database of general-interest information."{{rp|105}}

After consulting a group of experts in the videotex domain, the information scientists Grover & Sabherwal drew conclusions (1989) that largely concurred with Noll's. In addition, they judged that government subsidies were required to boost public interest and mass take-up.

{{

cite journal

|journal=Journal of Systems Management

|title=Poor Performance of Videotex Systems

|volume=40

|issue=6

|pages=31{{ndash}}37

|date=June 1989

|first1=Varun

|last1=Grover

|author1-link=Varun Grover (information scientist)

|first2=Rajiv

|last2=Sabherwal

|url=https://www.proquest.com/docview/199811361

|id={{ProQuest|199811361}}

|issn=0022-4839

|oclc=928083662

}} 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 {{sic|nolink=y}} ... 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."

{{

cite book

|title=Pushbutton Fantasies : critical perspectives on videotex and information technology

|first=Vincent

|last=Mosco

|date=1982

|publisher=Ablex

|location=Norwood

|isbn=978-0-893-91125-6

|oclc=8626459

}}{{rp|77}}

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".

{{

cite journal

|journal=Journal of the American Society for Information Science

|title=The Social Shaping of Videotex: How Information Services for the Public Have Evolved.

|volume=45

|issue=7

|pages=483{{ndash}}497

|date=August 1994

|first=Donald O.

|last=Case

|issn=0002-8231

|oclc=802881625

|url=https://www.proquest.com/docview/216901916

|id={{ProQuest|216901916}}

}}{{rp|495}} He identified the envisioning of videotex as a facilitator of mass participation in an emerging information society

{{

cite journal

|journal=Bulletin of the Medical Library Association

|title=The Origin and Development of a Concept: The Information Society

|first=Susan

|last=Crawford

|date=1983

|volume=71

|issue=4

|pages=380{{ndash}}385

|pmid=6652297

|pmc=227258

|url=https://pmc.ncbi.nlm.nih.gov/articles/PMC227258/

|access-date=21 February 2025

}}{{snd}}a belief held and promoted by many politicians, futurists, sociologists, and business leaders in the 1960s and 1970s{{snd}}as a crucial spur to the development of the technology, sustained investment, and the roll-out of services.{{rp|485{{ndash}}487}} This vision was animated, according to communications technology researchers Harmeet & Sandvig's summary (2006) of scholarly views, by the "converging agendas of myriad players ... all seeking to increase revenues in otherwise saturated markets": phone companies (increased network traffic), set and terminal manufacturers (more sales), newspapers and news agencies (additional outlets for content), and business sectors such as banks and the travel trade (looking to reduce transaction costs).

{{

cite conference

|first1=Harmeet

|last1=Sawhney

|first2=Christian

|last2=Sandvig

|title=Approaching Yet Another New Communication Technology

|conference=International Communication Association (ICA): 56th Annual Conference

|pages=1{{ndash}}28

|date=20 June 2006

|location=Dresden

|id={{EBSCOhost|dbcode=ufh|27203868}}

}} {{requires subscription}}{{rp|13{{ndash}}14}}

Regarding Prestel, Case summarised the problems it faced (as described by a former chief executive)

{{

cite web

|title=Prestel, Escher, Bach: changes within changes

|publisher=Program on Information Resources Policy, Harvard University

|type=incidental paper

|first=Richard

|last=Hooper

|author-link=Richard Hooper (civil servant)

|date=January 1984

|id=I-84-1

|url=http://www.pirp.harvard.edu/pubs_pdf/hooper/hooper-i84-1.pdf

|archive-url=https://web.archive.org/web/20080607040301/http://www.pirp.harvard.edu/pubs_pdf/hooper/hooper-i84-1.pdf

|archive-date=7 June 2008

|access-date=20 February 2025

}} Reprinted in

{{

cite book

|title=Issues in New Information Technology

|editor-first=Benjamin M.

|editor-last=Compaine

|pages=15{{ndash}}24

|date=1988

|publisher=Ablex

|location=Norwood

|isbn=978-0-893-91468-4

|oclc=243361472

}} as the lack of a trigger service,{{refn|group=lower-alpha|A key service or feature that would have attracted subscribers and kept them engaged.}} low-quality information, complicated charges, competing services, and uncoordinated marketing by IPs, British Telecom, and terminal and adaptor providers.{{rp|492}} Insufficient market research into "what sorts of information people actually use, and what delivery modes are appropriate for them" was identified by public policy researchers Thomas & Miles (1989) as a further reason why Prestel failed to live up to expectations.{{rp|26}}

Poor, a communications researcher, suggested (2006) that the failure of Prestel to achieve significant mass-market take-up was linked to its "highly centralized and closed" nature.

{{

cite conference

|first=Nathaniel

|last=Poor

|title=When They Built the Internet and No One Came: The Failure of Videotex and the Triumph of Open Systems

|conference=International Communication Association (ICA): 54th Annual Conference

|pages=1{{ndash}}30

|date=May 2006

|location=New Orleans

|id={{EBSCOhost|dbcode=ufh|45284295}}

}} {{requires subscription}}{{rp|1}} He cited the control over content exercised by IPs and the system operator, British Telecom,{{rp|9}} coupled with a lack of connectivity to both non-videotex online services and other videotex services based on different technical standards.{{rp|23{{ndash}}24}} On standards, Poor (2004) believed that "A universal videotex standard would have been like the common gauge for railroad, or common standards for the telegraph or the telephone. Disparate systems could connect, and enjoy network externalities due to scale."

{{cite thesis

|first=Nathaniel

|last=Poor

|date=2004

|title=Democratic technologies: Openness, decentralization, and the success of information systems

|chapter=Chapter 5: Videotex: control and communication in the decade before the Internet

|pages=150{{ndash}}184

|degree=PhD

|publisher=University of Michigan

|id={{ProQuest|305181173}}

|url=https://www.proquest.com/docview/305181173

|isbn=978-0-496-85092-1

|oclc=148537515

}}{{rp|181 ft 24}}

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.{{refn|group=lower-alpha|I.e, page numbers could run from 0 to 999999999.}}

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.

{{cite book

|first=Rex

|last=Winsbury

|author-link=Rex Winsbury

|title=The Electronic Bookstall : Push-button publishing on videotex: a critical study of Prestel in Britain

|date=1979

|publisher=International Institute of Communications

|location=London

|isbn=978-0-904-77610-2

|oclc=5507588

|url=https://archive.org/details/electronicbookst0000wins

|url-access=registration

}}{{rp|20{{ndash}}21}}

{{

cite document

|author=British Telecom

|author-link=BT Group

|date=September 1982

|type=Customer brochure

|title= Prestel

|location= London

|publisher=Prestel Public Relations

|id=Prestel P526 9/82

}}{{rp|2}}

{{

cite web

|url=https://archive.org/details/acorn-prestel-system-user-guide-bbc-micro/

|access-date=7 October 2024

|title=Prestel System User Guide{{snd}}BBC Micro

|date=March 1984

|author=Acorn Computers

|author-link=Acorn Computers

|via=Internet Archive

}}{{rp|2}}

Each IP rented a three-digit number as its master page. For example, the Meteorological Office's was 209,{{rp|6}} and the numbers identifying all its pages began with these digits{{snd}} such as for 20971, the page for "Aviation forecasts".{{rp|1}}

Single- and double-digit pages were reserved by Prestel for system information purposes, such as page 1, which showed the main index. Pages starting with 9 were for account and other system management functions: page 92, for example, showed details of a Prestel user's bill.{{rp|10}}

Most frames were set up to provide information. Other types were for messaging, or provided a gateway to services on other computers. A "follow-on" type caused the next frame in sequence to be automatically displayed as soon as the current frame had filled the screen.

By embedding cursor-control characters in the page, simple animations could be produced by rewriting parts of the screen already displayed. These were known as "dynamic frames".

{{

cite magazine

|magazine=Amstrad Computer User

|title=Prestel{{snd}}living by numbers

|page=36

|issue=6

|date=May 1985

|url=https://archive.org/details/AmstradComputerUser06-0585/page/n35/mode/1up

|quote=One of the latest features of Prestel is the dynamic page. Usually a page only shows a static image, either text or a diagram[.] By using a dynamic frame it is possible to animate the graphics. This works by sending commands to the user’s system to move the cursor and then print another bit.

|access-date=19 March 2025

|via=Internet Archive

}}{{refn|group=lower-alpha|Dynamic frames could not be created online: their preparation required specialist software and then uploading via the "bulk update" facility. No timing options were available beyond those imposed by the transmission speed, which was usually 1200 baud.}} 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.{{citation needed|date=March 2025}}

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.{{refn|group=lower-alpha|The first few frames acted as headers. For example, a program would be described on frames 70067a and b, while frame c gave the number of subsequent frames containing the program, and a checksum.The telesoftware program itself started in frame d. To verify a successful download, software compared the checksum with a value calculated from the result of downloading all the frames required. If the check failed, the program had to be downloaded again.{{rp|30}}}}{{rp|30{{ndash}}31}}

Each frame had 24 lines of 40 characters each, and as in the format used by the Ceefax and ORACLE teletext services, could contain a maximum of 960 characters. The bottom line was reserved for system messages, leaving 920 characters for the Information Provider (IP). The top line, showing the name or logo of the IP, the page number, and the price,{{rp|7}} occupied at least 43 characters, depending on the design of the logo. This left 22 lines and a maximum 877 characters available for the IP to present information to the user.

{{

cite web

|url=https://archive.org/details/prestel-bulk-update-technical-specification-november-1981-page_numbers_added/

|access-date=7 October 2024

|title=Prestel Bulk Update Technical Specification

|date=November 1981

|id=Ref. 14 9 81p

|author=British Telecom

|author-link=BT Group

|via=Internet Archive

}}{{rp|12}}

When preparing and editing a page, an IP could use upper- and lower-case letters, digits, punctuation marks, a few arithmetic symbols, and a set of "mosaic characters" for composing rudimentary graphics.{{rp|19}}{{refn|group=lower-alpha|The character set conformed with a variant of the ISO/IEC 646 and CCITT standards; it was formalised in the 1981 CEPT videotex standard as the CEPT3 profile.

{{

cite web

|title=Terminal Equipment (TE): videotex presentation layer protocol, videotex presentation layer data syntax

|id=ETS 300 072

|date=November 1990 |url=http://www.etsi.org/deliver/etsi_i_ets/300001_300099/300072/01_60/ets_300072e01p.pdf

|publisher=ETSI

|location=Sophia Antipolis

|access-date=9 October 2024

}}}} The appearance of a character could be changed using a display-attribute code.{{rp|37}} These modified the appearance of subsequent characters on the same row of the screen, and themselves occupied one character position, which was displayed as a space.

{{

cite document

|author=British Telecom

|author-link=BT Group

|date=August 1980

|type=Technical brief

|title= Prestel. The Technology.

|location=London

|publisher=Prestel Public Relations

|id=P507/8/80

}}{{rp|15}}

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.

{{

cite web

|url=https://ia801907.us.archive.org/21/items/prestel-mills-allen-1979/Prestel_MillsAllen_1979_text.pdf

|access-date=15 April 2025

|via=Internet Archive

|title=Prestel, the editorial opportunity: A report of the first year of editorial research

|date=March 1979

|publisher=Mills & Allen Communications

|location=London

|type=research report

}}{{rp|1{{ndash}}2}} Several graphics designers were consulted (including the designer of Prestel's logo and its index and system pages),

{{

cite journal

|journal=American Fabrics and Fashions

|title=Pentagram: Prestel

|first=Mervyn

|last=Kurlansky

|issue=127

|pages=66{{ndash}}67

|date=1982

|via=ASU FIDM

|id=Accession no. SC2011.1168.60

|issn=0748-3228

|quote=In terms of typography, we were faced with limitations that put us back 2,000 years.

|quote-page=66

}} 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.{{rp|18{{ndash}}19}} Building on the study's results and the outcomes of other research, Reynolds (1979) made recommendations for presenting text, tables, indexes and graphics in Prestel-type videotex systems and in teletext.

{{

cite journal

|journal=Information Design Journal

|title=Teletext and viewdata{{snd}}a new challenge for the designer

|first=Linda

|last=Reynolds

|volume=1

|issue=1

|date=1979

|pages=2{{ndash}}14

|doi=10.1075/idj.1.1.02rey

|issn= 0142-5471

|quote=[B]ecause the medium is less than perfect for reading, it is all the more important that the presentation in terms of layout and the use of colour should be optimal.

|quote-page=13

}}

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.{{rp|12}} On style, the study's report highlighted the views of the writer and academic Raymond Williams:{{refn|group=lower-alpha|Concluding remarks at the study's Writing for Prestel seminar, London, 15 November 1978.}} "The English sentence is a very flexible animal, and we all know what happened to it with the invention of printing. We shouldn't feel confined by it in Prestel."{{rp|2.8}}

Surveying how Prestel's content had developed a year or so after its commercial launch, Rex Winsbury, a media journalist and editorial director of Fintel,{{refn|group=lower-alpha|Fintel was a joint venture between the Financial Times and Extel.}} a major IP, wrote:

{{

cite book

|editor-first=Rex

|editor-last=Winsbury

|editor-link=Rex Winsbury

|title=Viewdata in Action : a Comparative Study of Prestel

|date=1981

|publisher=McGraw-Hill

|location=London

|first=Rex

|last=Winsbury

|author-link=Rex Winsbury

|chapter=Electronic editing: database and page design

|pages=145{{ndash}}154

|chapter-url=https://archive.org/details/viewdatainaction0000unse/page/145/mode/1up

|isbn=978-0-070-84548-0

|oclc=715473323

|url=https://archive.org/details/viewdatainaction0000unse

|url-access=registration

|access-date=26 February 2025

}}{{rp|151}}{{blockquote|text=[E]diting demands that something useful be said on each page without fuss or flannel in a very short space. Viewdata does not like long sentences or qualifications. Nor must you cram too many words on to the screen; otherwise it looks a mess. Each page has to have a single message, and a clear one at that. Two short paragraphs ... or a few columns of figures to a page, are the most you will find ... It comes down to what newspapermen {{sic|nolink=y}} call "tight subbing".}}

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.{{rp|20}} Double-digit links{{snd}}such as "56"{{snd}}were achieved by linking the first digit to an intermediate, stepping-stone frame on the IP's database: this, in turn, connected the second digit to the target page.

{{

cite journal

|journal=Information Scientist

|title=Viewdata{{snd}}a Review

|first=Martin S.

|last=White

|volume=12

|issue=4

|pages=144{{ndash}}153

|date=December 1978

|issn=0020-0263

|url=https://archive.org/details/viewdata-a-review-white-m-s-1978

|access-date=27 January 2025

|via=Internet Archive

}}{{rp|149}}

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 information{{snd}}referred to as an "index page"; and at the other, a screenful of information with few, if any, links to other pages{{snd}}an "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."{{rp|22}}

File:Prestel videotex service database - "inverted tree" structure.pngWhen the public Prestel service began in 1979, a user connecting to the system was presented with the main index page. As they made and keyed successive menu choices, they moved down a subject hierarchy, from the general to the specific, to finish with the information page they sought.

{{

cite journal

|journal=Information Design Journal

|first=Elizabeth

|last=Orna

|title=Information management by design: improving information retrieval on Prestel

|date=1986

|volume=5

|issue=1

|pages=61{{ndash}}68

|doi=10.1075/idj.5.1.04orn

|issn=1569-979X

}}{{rp|61}} The Post Office, academics, and the media referred to this hierarchical database arrangement as a tree structure or "inverted tree".

{{

cite web

|title=Database Organisation and Information Retrieval{{snd}} a discussion paper

|first=Ederyn

|last=Williams

|author-link=Ederyn Williams

|date=18 July 1978

|website=www.whatdotheyknow.com

|id=BL: SGV 78/10. PO: PO-IP CP-26

|url=https://www.whatdotheyknow.com/request/prestel_site_1980s_4/response/73455/attach/4/Structuring%20BL%20Information.pdf

|access-date=14 October 2024

|quote=The database was initially organised on the 'tree principle', in which pages were organised into a single massive tree, and page access was presumed to be primarily through a series of single digit choices.

|quote-page=1

}} Note: this Post Office document was published by WhatDoTheyKnow as part of the outcome of a Freedom of Information request [https://www.whatdotheyknow.com/request/prestel_site_1980s_4/ made to The British Library in February 2010.]{{rp|1}}

{{

cite journal

|journal=Journal of Information Science

|title=The future of videotex systems{{snd}}a personal view

|first=I. N. J.

|last=Storey

|date=1982

|volume=4

|issue=2{{ndash}}3

|pages=111{{ndash}}115

|doi=10.1177/016555158200400207

|issn=0165-5515

}}{{rp|112}}

{{

cite news

|newspaper=Guardian

|title=How the Post Office failed to deliver

|date=13 September 1984

|page=17

|first=Jack

|last=Schofield

|author-link=Jack Schofield (journalist)

|url=https://www.proquest.com/docview/186463562

|id={{ProQuest|186463562}}

|url-access=subscription

|quote=The tree structure means a large proportion of the frames are simply 'routeing' frames. They contain no useful information, but simply direct you on the long route to where that information is held.

}} [column 2]{{rp|col. 2}}

File:Prestel videotex service database - backlinks.png

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.{{rp|62{{ndash}}63}}

As Prestel developed, IPs accommodated the particularities of the different types of information and services they provided, and the expectations of their users, through the extensive use of backlinks and crosslinks between their pages.{{rp|9}} This resulted in a variety of database structures{{rp|104{{ndash}}105}} that acquired labels such as cartwheels, ring-of-rings, Chinese lanterns and lobster-pots to help visualise how pages were connected.{{rp|24}}

{{multiple image

| total_width = 250

| footer = Pocket guide to Prestel for medical practitioners, {{circa|lk=no}} 1984. Their welcome page was 1629.

{{

cite journal

|journal=Medical Informatics

|date=1982

|volume=7

|issue=2

|pages=141–142

|author=

|title=Short progress report: Present and potential uses of Prestel by the medical profession

|doi=10.3109/14639238209010707

}}

Laminated card, 6.9 x 11 cm

| image1 = Prestel-for-Medics pocket-guide front.png

| alt1 = Front of guide

| caption1 = front

| image2 = Prestel-for-Medics pocket-guide back.png

| alt2 = Back of guide

| caption2 = back

}}There were three basic navigation commands:{{rp|20}}

• *number# took the user directly to the first frame of the page number specified: for example, *5052# displayed the contents of 5052a onscreen;
• # moved the user successively forward through the frames: 5052b, 5052c, and so on;
• *# returned the user to the previous page in strict sequence, and could be repeated three times.

Keyword access was introduced in 1987, with *keyword# taking the user directly to the subject (or subject index) specified.

{{

cite journal

|journal=The Indexer

|title=Prestel indexing from the user's point of view

|first=Robin

|last=Yeates

|date=April 1988

|volume=16

|issue=1

|pages=7{{ndash}}10

|doi=10.3828/indexer.1988.16.1.3

|issn=1756-0632

}}{{rp|8}}{{rp|20}}

A topic index, updated daily, was published on page 199, and an IP index on page 198. A printed A{{nbnd}}Z Start-Up Directory of the topics available on Prestel, with the appropriate page number to key, was sent to new users. From 1987, the topic names could also be used as keywords.

{{

cite document

|author=British Telecom

|date= 1 September 1987

|title=Prestel Start-Up Directory

|location=London

|publisher=Prestel

|type=handbook

}} Micronet 800, an IP, visualised the relationships between its pages in a London Tube-style schematic map as part of a guide for users.

{{

cite web

|url=https://archive.org/details/your-guide-to-micronet-1986/mode/2up

|title=Your Guide to Micronet

|page=4

|date=1986

|publisher=Telemap

|location=London

|via=Internet Archive

}}

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.{{refn|group=lower-alpha|{{ISSN|0266-0288}}. {{OCLC|1230877457}}.}} This was superseded by Connexions, sent to users every two months till May 1988.

{{

cite web

|url=https://www.computinghistory.org.uk/det/24135/Connexions-April-May-1988/

|access-date=16 October 2024

|title=Connexions [cover]

|date=April–May 1988

|publisher=British Telecom

|website=Centre for Computing History

|id=CH24135

|issn=0951-3140

|oclc=220057513

}} A directory was also incorporated into the quarterly Prestel Business Directory published by the Financial Times from 1979.

{{

cite web

|url=https://www.computinghistory.org.uk/det/56750/Prestel-Business-Directory-(Oct-1981)/

|access-date=16 October 2024

|title=Prestel Business Directory [cover]

|date=October 1981

|publisher=Financial Times Business Publishing

|issn=0142-5102

|oclc=225634964

|website=Centre for Computing History

|id=CH56750

}}

From January 1986, Prestel published Focus magazine on page 123 "to show you the most useful, entertaining and topical pages from the thousands available."

{{

cite document

|first=Yvonne

|last=Hicks

|date=January 1986

|type=customer newsletter

|title=Prestel Offline

|location=London

|publisher=Prestel Public Relations

|at=p. 1, col 1, "Focus on Prestel "

}} It spotlighted news, sport, weather, and entertainment information on a daily basis, and included weekly features.

{{

cite magazine

|magazine=The Prestel Directory

|title=A day in the life of Focus

|first=Sanchie

|last=Heesom

|page=66

|date=1986

|issue=2

|publisher=Directel

|location=Birmingham

|issn=0266-0288

}}

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

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,

{{

cite web

|url=https://archive.org/details/prestel-ip-and-user-prices-oct-1982

|title=Information Provider (IP) Charges and User Charges

|author=British Telecom

|date=October 1982

|access-date=8 October 2024

|via=Internet Archive

}}{{rp|1}} equivalent to around £29,000 in 2021.

{{

cite web

|url=https://www.measuringworth.com/calculators/ukcompare/

|title=Five Ways to Compute the Relative Value of a UK Pound Amount, 1270 to Present

|publisher=The MeasuringWorth Foundation

|access-date=9 October 2024

}}

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), while using "Closed User Groups" (CUGs){{refn|group=lower-alpha|name=CUG|A Closed User Group, or CUG, was a group of Prestel users, set up by an Information Provider, with access to confidential information.{{rp|18}}}} and the sub-IP facility each cost £250 annually{{rp|1}} (over £1,300 in 2021).

Sub-IPs{{snd}}those with smaller requirements or budget{{snd}}rented pages from a main IP.

{{

cite journal

|journal=Post Office Electrical Engineers' Journal

|title=Prestel: The First Year of Public Service

|first=W. R.

|last=Broadhead

|volume=74

|issue=2

|pages=129{{ndash}}133

|date=July 1981

|url=https://archive.org/details/poeej198107/page/n63/mode/1up

|access-date=7 October 2024

|via=Internet Archive

}}{{rp|130}} 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{{rp|1}} Sub-IPs had a four-digit (or more) master-page within a main IP's area. Generally speaking, they could only edit existing pages, and were not able to create or delete them.

The cost to an IP of connecting an external computer to the Prestel system varied according to the number of simultaneous users required, the distance between Prestel and the IP's computer, and whether the connection was made using a private line or via the PSS packet-switched network. There were also time and data-volume charges.

{{

cite document

|title=Prestel Travel Tariff Guide

|date=November 1985

|type=brochure

|publisher=Prestel Travel

|location=London

}}{{rp|3}} 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.

{{

cite web

|url=https://archive.org/details/Welcome-to-Prestel-Gateway

|title=Welcome to Gateway

|date=1982

|type=brochure

|publisher=Prestel Public Relations

|location=London

|via=Internet Archive

|access-date=13 January 2025

}}{{rp|12{{ndash}}13}}

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.{{rp|4}}

Several typical relationships developed between umbrella IPs and their sub-IP clients. A sub-IP could be:{{rp|99}}

• An independent supplier of information, with exclusive or partial editorial control and full or partial editing rights.
• An organisation making information available to an IP, sometimes on a royalty basis.
• An organisation advertising on an IP's pages.
• An individual authoring articles or columns for an IP, usually on a royalty basis.

In addition, the IP Micronet 800 used the sub-IP facility to offer the "Gallery" service, where a group, club, or individual could rent one or a number of frames cheaply, and for short periods if required.{{

cite magazine

|magazine=Log On{{snd}}The magazine for Micronet members

|title=Gallery

|first=Julian

|last=Hayward

|issue=7

|pages=13{{ndash}}14

|date=Spring 1989

|publisher=Telemap

|location=London

|url=https://www.viewdata.org.uk/download.php?cat=15_Prestel&file=logon07.pdf#page=13

|archive-url=https://web.archive.org/web/20181115002855/https://www.viewdata.org.uk/download.php?cat=15_Prestel&file=logon07.pdf#page=13

|archive-date=15 November 2018

}}

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.

{{

cite book

|editor-first=Rex

|editor-last=Winsbury

|editor-link=Rex Winsbury

|title=Viewdata in Action : a Comparative Study of Prestel

|date=1981

|publisher=McGraw-Hill

|location=London

|first=Tim

|last=Chapman

|chapter=Using an 'umbrella'

|pages=155{{ndash}}163

|chapter-url=https://archive.org/details/viewdatainaction0000unse/page/155/mode/2up?view=theater

|isbn=978-0-070-84548-0

|oclc=715473323

|url=https://archive.org/details/viewdatainaction0000unse

|url-access=registration

|access-date=21 November 2024

}}{{rp|156{{ndash}}159}}

{{see also|#Network}}

File:Prestel Deccafax-viewdata-terminal +-Cherry-Editing-Keyboard.jpg, connected to a Deccafax Viewdata Terminal Model VP1 manufactured (1979{{ndash}}1994) by Decca Radio & Television. Keyboard 11 x 50 x 31 cm, terminal 42 x 45 x 45 cm, 28 kg

{{

cite web

|url=https://collection.sciencemuseumgroup.org.uk/objects/co34240/deccafax-viewdata-terminal-model-vp1-1979-1994

|title=Deccafax Viewdata Terminal Model VP1, 1979-1994, and Cherry Editing Keyboard

|website= Science Museum Group Collection Online

|publisher=Science Museum Group

|date=23 June 2014

|access-date=5 October 2024

|id=Object number 1994-1169: donated by House of Commons}}]]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.{{rp|2, 6{{ndash}}7}}

Using the online editor, IPs were also able to view information about a page hidden from ordinary users, such as the time and date of its last update, whether the frame was in a Closed User Group (CUG),{{refn||group=lower-alpha|name=CUG}} the price-to-view (if any), and the "frame count"{{snd}}the number of times the frame had been accessed.{{refn|group=lower-alpha|The frame count was not cumulated over all IRCs, but related only to the computer being viewed at the time: calculating national access counts was a manual exercise.}}

IPs and sub-IPs accessed the Edit computer using their normal ID and password, but had a separate password to access the editing facility. Bulk uploads only required the edit password and the IP's account number.

Prestel's pre-launch promotional material focused on the general public:{{blockquote|Prestel is for everyone. Busy mothers can check out prices before they go shopping or their children can use Prestel to help them with their homework. Gardeners will have a constant source of information on what they should be doing at any particular time of the year. Whole families can choose and even book their holidays through Prestel. [..] Prestel will provide you with listings for theatres, cinemas, sporting events, exhibitions and just about anything else

that may be going on.

{{

cite document

|title=Prestel

|date=January 1979

|type=brochure

|publisher=Post Office Telecommunications

|location=London

}}{{rp|3}}}} When the service launched in late 1979, Post Office Telecommunications had a hands-off approach towards managing whatever IPs placed on the system.

{{

cite web

|url=https://archivesit.org.uk/wp-content/uploads/2021/09/BCF-MISC-01-1985-Iss1.pdf

|access-date=17 October 2024

|title=Videotex in Europe

|date=January 1985

|author=Butler Cox

|publisher=Butler Cox & Partners

|location=London

|series=Butler Cox Report Series #19

|website=Archives of IT

|oclc=12808197

}}{{rp|25}} 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.{{rp|25}}

By the mid-1980s, the specialised services on Prestel included:{{rp|15{{ndash}}18}}

• Prestel CitiService, involving the London Stock Exchange and ICV Information Systems, targeted three groups: the business community as a whole, with mainly company information; private investors in a closed user group{{refn|group=lower-alpha|name=CUG}}, offering regularly updated share prices; and for brokers and other investment professionals, continuously updated share prices, also in a closed user group.

{{

cite news

|newspaper=CITINEWS : The newsletter of Prestel CitiService

|title=CitiService doubles its speed to meet demand

|date=Winter 1985{{ndash}}1986

|page=1

|volume=1

|issue=3

|publisher=ICV Information Systems

}}

• 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.

{{

cite book

|title=Centre of Management in Agriculture Yearbook 1984/1985

|date=June 1985

|url=https://www.iagrm.com/content/large/journals/cma/1984-85/centre-of-management-in-agriculture-yearbook-1984-85-lowres.pdf#page=67

|chapter=Prestel Farmlink

|first=Thea

|last=James

|pages=65, 67

|via=Institute of Agricultural Management

|access-date=30 November 2024

}}

• Banking: the Nottingham Building Society offered Homelink, and the Bank of Scotland HOBS, the Home & Office Banking Service.

{{

cite newspaper The Times

|title=New from Bank of Scotland. Home Banking throughout the UK.

|date=23 February 1985

|at=p. 29: full-page advertisement showing six types of banking transactions on Prestel pages

|department=Family Money

|issue=62070

|url=https://www.thetimes.com/tto/archive/page/1983-04-26/22.html

}} 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.

{{

cite document

|title=Prestel Microcomputing will add a new dimension to your home computing

|date=May 1984

|type=letter

|author=Prestel Microcomputing

|publisher=British Telecom

}}

• Prestel Education targeted schools and colleges, and provided course and careers advice, educational software, and help with using computers.

{{

cite newspaper The Times

|title=Schools given chance to plug into micro pages

|first=Bill

|last=Johnstone

|date=29 January 1985

|page=3

|issue=62048

|url=https://www.thetimes.com/tto/archive/page/1985-01-29/3.html

}}

• British Telecom Insurance Services provided financial information to insurance intermediaries and enabled them to get online quotes from major insurance companies.

{{

cite news

|newspaper=The Guardian

|date=14 December 1987

|title=Ask me another: a new information service for the insurance industry

|first=Bob

|last=Rodwell

|page=22

|url=https://www.proquest.com/docview/186749481/

}}

• Prestel Teleshopping was a specialised e-commerce service for the residential market, and involved Littlewoods, Grattan, and Kays Catalogues, among others.

{{

cite journal

|journal=British Telecom Journal

|title=Armchair shopping delivers the goods

|first=Jane

|last=Young

|volume=8

|issue=2

|date=Summer 1987

|pages=76{{ndash}}77

|url=https://archive.org/details/btj-198707/page/n91/mode/2up

|access-date=30 November 2024

|issn=0260-1532

|oclc=8560549

|via=Internet Archive

}} Shows two "Kays Catalogues Teleshop" frames.

• 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.

A "response frame" enabled a user to send a message to an IP using a preformatted page to order goods or services{{rp|133}} or to transmit data.

{{

cite journal

|journal=British Medical Journal (Clinical Research Edition)

|title=Use of a viewdata system to collect data from a multicentre clinical trial in anaesthesia

|first1=H. A.

|last1=Waldron

|first2=R. F.

|last2=Cookson

|volume=289

|issue=6451

|pages=1059{{ndash}}1061

|date=20 October 1984

|issn=0267-0623

|url=https://www.bmj.com/content/bmj/289/6451/1059.full.pdf

|access-date=9 December 2024

|doi=10.1136/bmj.289.6451.1059

|doi-access=free

}}

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. {{section link|#Network}}

Image:page-7.png

Prestel Mailbox was launched in 1983. Initially hosted on a computer in London, it was later made available UK-wide. {{section link|#Network}}

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

{{

cite web

|title=Mailbox, a Prestel Message Service : User Guide and Personal Directory

|type=booklet

|publisher=Prestel Message Services

|location=London

|date=1983

|at=See foot of pages A, B, C, E, F, I, M, T, and V.

|url=https://archive.org/details/prestel-mailbox-user-guide-1983/

|access-date=31 January 2025

|via=Internet Archive

}}

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.

{{

cite web

|url=https://archive.org/details/prestel-customer-handbook-1987/

|access-date=7 October 2024

|title=Prestel Customer Handbook

|date=1987

|author=British Telecom

|author-link=BT Group

|via=Internet Archive

}}{{rp|8}} 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.{{rp|29}}

Image:Prestel-Mailbox message-received screenshot-1984.png . At bottom are instructions for storing or deleting the message.

{{

cite episode

|title=Using Prestel

|series=Database

|date=7 June 1984

| minutes=3:08 |url=https://www.youtube.com/watch?v=szdbKz5CyhA |network=Thames TV

|season=

|number=

|last=Ashton

|first=Jane (host)

|via=YouTube

}}]]

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.{{refn|group=lower-alpha|Ex-directory Prestel Mailbox numbers used a dummy phone number format starting with 01999 or 01111.{{citation needed|date=February 2017}}}}

Image:Prestel-Mailbox lapel-badge.pngWhen 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. {{See section|#Mailbox upgrade}}

Image:Prestel Simpatico index page on 4 September 1985.tif

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{{nbsp}}...

{{

cite magazine

|magazine=The Prestel Directory

|title=Simpatico

|date=1985

|issue=4

|at=p. 56 col 2

|publisher=Directel

|location=Birmingham

|issn=0266-0288

}}

Prestel Mailbox was extended in 1984 to give access to the Telex service via "Telex Link". On *8#, the Telex Link entry page, a message could be composed, the destination country chosen, 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.

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.

{{

cite web

|url=https://archive.org/details/Prestel-telex-link-info-sheet/

|access-date=7 October 2024

|title=Telex Link: Low Cost Access to Telex

|date=August 1986

|author=British Telecom

|author-link=BT Group

|via=Internet Archive

}}

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

{{

cite document

|author=British Telecom

|author-link=BT Group

|date=January 1987

|type=customer newsletter

|title=Prestel Offline

|location=London

|publisher=Prestel Public Relations

|at=p. 1, col 1, "Out with the old ... "

}}

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.

{{

cite magazine

|magazine=Log On{{snd}}The magazine for Micronet members

|title=Mailbox Mark Two: so what's in it for you?

|issue=9

|pages=10{{ndash}}11

|date=Autumn 1989

}} An interview with Chris Ramsey, the Mailbox manager. Basic word-processing was also possible.

{{

cite web

|title=Prestel Mailbox User Guide

|type=booklet

|publisher=Prestel

|location=Hemel Hempstead

|date=July 1989

|url=https://archive.org/details/prestel-mailbox-user-guide-1989

|access-date=30 January 2025

|via=Internet Archive

}}{{rp|16{{ndash}}17}}

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.

{{

cite web

|url=https://archive.org/details/prestel-upgraded-mailbox-charges-from-July1989/

|access-date=9 October 2024

|title=Mailbox Charges

|date=June 1990

|publisher=British Telecom

|via=Internet Archive

}}

By 1984, Prestel users were sending messages at the rate of around 71,000 per month via a computer in London.{{rp|142}} The average number per month in early 1984 was 186,000, of which 125,000 were response frames and 61,000 Mailbox messages.

{{

cite document

|title=Prestel Briefing

|date=April 1984

|at=Issue 1

|type=brochure

|publisher=Public Relations Department, Prestel

|location=London

}}{{refn|group=lower-alpha|The "Prestel Briefing" sources cited state that these figures "do not include activity conducted with external computers through Prestel Gateways".}}

In September 1985, after Mailbox became a national service, the chief executive of the part of British Telecom responsible for Prestel stated that 100,000 "electronic mail messages"{{snd}}Mailbox messages and response frames{{snd}}were being sent each week, with 60,000 terminals attached to the system.

{{

cite news

|newspaper=The Guardian

|date=26 September 1985

|title=Prestel's pride

|first=Richard

|last=Hooper

|page=17

|url=https://www.proquest.com/docview/186640055

|id={{ProQuest|186640055}}

}} The average weekly figure rose to 130,000 in December 1985.

{{

cite document

|title=Prestel Briefing

|date=February 1986

|at=Issue 4

|type=brochure

|publisher=Public Relations Department, Prestel

|location=London

}}

{{expand section|further statistics accompanied by citations|date=November 2024}}

A security breach of the Prestel mailbox of Prince Philip, Duke of Edinburgh occurred in November 1984

{{

cite newspaper The Times

|title=Duke's mail code is cracked

|department=News

|date=6 November 1984

|page=2

|issue=61977

|column=3

|url=https://www.thetimes.com/tto/archive/article/1984-11-03/2/7.html

}} as part of a wider hack of Prestel.

{{

cite web

|url=https://www.bbc.com/news/technology-36306419

|title=Archive of historic BT 'email' hack preserved

|website=BBC

|date=19 May 2016

|access-date=26 October 2024

}}

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.

{{

cite journal

|journal=British Telecommunications Engineering Journal

|title=Prestel terminals

|first=G. D.

|last=Hudson

|volume=1

|issue=1

|pages=35{{ndash}}41

|date=April 1982

|access-date=3 December 2024

|url=https://archive.org/details/bte-198204/page/n38/mode/1up

|issn=0262-401X

|via=Internet Archive

}} Pictured in the article are a Philips residential terminal equipped for Prestel, teletext and normal television reception, a Sony business terminal with message keyboard, a Zycor Prestel adaptor with a normal domestic television, and a Metrotech information provider editing terminal.

Several types of Prestel terminal were produced:{{rp|75{{ndash}}77}}

• integrated residential terminals, typically based on television sets;
• integrated business terminals;
• adaptors for television sets;
• adaptors for microcomputers, with associated or standalone editing software;
• editing terminals.

In March 1979, the Post Office launched a limited "London Residential Service" for subscribers in the capital. This was based on the computer used in an earlier test phase to both store the Prestel database and enable IPs to make updates to their pages.

{{

cite book

|title=Viewdata: A Public Information Utility

|first=Adrian V.

|last=Stokes

|author-link=Adrian V. Stokes

|date=1980

|publisher=Input Two-Nine

|edition=2nd

|location=Purley

|isbn=978-0-905-89753-0

|oclc=6972310

}}{{rp|22{{ndash}}23}}

When the full commercial service launched in September 1979, three new computer centres were opened in London.{{rp|130}} Two, known as Byron and Juniper, were "Information Retrieval Centres" (IRCs): their computers each contained a copy of the Prestel database, and were accessible by users. The third, Duke, was Prestel's "Update Centre" (UDC): IPs used this to create, modify or delete their pages, with their updates sent to the IRCs.{{refn|group=lower-alpha|The computer centres in London were first located in St Alphage House, together with Prestel's National Operations Centre (NOC). The computers and the NOC were later moved to Baynard House, which acted as a combined UDC and IRC. Both types of machine remained in service there till Prestel was discontinued in 1994.}} A fourth IRC, Dickens, opened in Birmingham in December.{{rp|115{{ndash}}116}}

IRCs were connected to the UDC in a star network configuration using leased-line connections (based on the X.25 protocol) operating at 2400 baud.

{{

cite report

|first=Barry

|last=Scott

|date=September 1980

|title=Viewdata and Training: What, Where and How Much

|page=7

|url=http://jesseheines.com:8080/~heines/academic/papers/1978dectechrpts/techrpt09.pdf

|publisher=Digital Equipment Corporation Educational Services

|publication-place=Burlington

|series=Technical Report No. 9

|access-date=8 October 2024

}} This network handled about 2,000 Prestel terminals and provided users with over 160,000 pages supplied by around 130 IPs.

{{cite thesis

|first=Dorian James

|last=Rutter

|date=2005

|title=From Diversity to Convergence: British Computer Networks and the Internet, 1970{{ndash}}1995

|chapter=Chapter 4: Before the Internet: the Rise and Fall of Prestel

|pages=105{{ndash}}158

|chapter-url=https://wrap.warwick.ac.uk/id/eprint/1197/1/WRAP_THESIS_Rutter_2005.pdf#page=131

|degree=PhD

|publisher=University of Warwick

|url=https://wrap.warwick.ac.uk/id/eprint/1197/1/WRAP_THESIS_Rutter_2005.pdf

|oclc=93065596

}}{{rp|116}} 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 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.{{rp|130}}

By June 1980, the network had grown to four individual information-retrieval computers in London, and six others installed in pairs in each of Birmingham, Edinburgh and Manchester, making ten in all.

{{

cite report

|date=October 1980

|title=Videotex Systems and Services

|first1= L. R.

|last1=Bloom

|first2=A. G.

|last2=Hanson

|first3=R. F.

|last3=Linfield

|first4= D. R.

|last4=Wortendyke

|chapter=Section 2.2: The United Kingdom

|page=18

|publisher=U.S. Department of Commerce

|location=Boulder

|id=NTIA Report 80-50

|url=http://www.its.bldrdoc.gov/pub/ntia-rpt/80-50/80-50.pdf

|archive-url=https://web.archive.org/web/20110606112803/http://www.its.bldrdoc.gov/pub/ntia-rpt/80-50/80-50.pdf

|archive-date=6 June 2011

|access-date=8 October 2024}}

These ten computers could initially connect to around 1000 user ports, expandable to 2000.{{rp|130}} At this point, the Prestel database contained about 164,000 pages with expandability to up to 260,000 built in: allowing for system management pages, this arrangement capped the size of the public database at around 250,000 frames.{{rp|133}}

By September 1980, there were five IRC machines in London and pairs of machines in Birmingham, Nottingham, Edinburgh, Glasgow, Manchester, Liverpool and Belfast, offering a total of 914 user ports. Further IRCs were planned in Luton, Reading, Sevenoaks, Brighton, Leeds, Newcastle, Cardiff, Bristol, Bournemouth, Chelmsford and Norwich by the end of 1980. By the end of 1980, 1500 user ports were available.

As of July 1981, the number of IRC computers had grown to 18: this increased the percentage of phone subscribers who could access Prestel at local call rates from 30% to 62%.{{rp|129}} In April 1984, Prestel announced that this had risen to 94%,{{rp|3}} and in February 1986, to 98%.{{rp|4}}

In late 1981, an IRC called Jefferson opened in Boston, Massachusetts, giving US subscribers access to Prestel via the American Telenet packet-switched network.

{{

cite journal

|journal=InfoWorld

|issn=0199-6649

|title=Prestel starts operation in the United States

|volume=4

|issue=5

|pages=1, 6

|date=8 February 1982

|first=David

|last=Needle

|url=https://books.google.com/books?id=eD4EAAAAMBAJ&pg=PA1

}}

{{

cite journal

|journal=British Telecom Journal

|issn=0260-1532

|title=Prestel news

|volume=2

|issue=4

|page=35

|date=1981–1982

|oclc=8560549

}}

{{see also|#Mailbox}}

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.{{rp|11 col 1}}

Prestel's computers were based on the GEC 4000 series minicomputer. The main IRC machines were originally model GEC 4082s equipped with 384 Kbyte memory-core stores, six 70 Mbyte hard disk drives, and 100 ports.{{refn|group=lower-alpha|By 1981, this configuration had changed: memory was doubled to 768 kbytes and data discs reduced to six (corresponding to the number at the IRC machines), with a single transaction disc.{{rp|131}}}} This set-up accommodated an initial 1500 Prestel users.

Each IRC computer had 208 ports. With eight reserved for testing and control, a computer could support up to 200 simultaneous Prestel users. For the ordinary user, access was via an asynchronous, duplex interface provided by banks of multiplexers. These, in turn, were accessed via standard modems, operating at 1200/75 bit/s, directly connected to the public phone network.{{rp|130}}

Besides the multiplexers required to support 1200/75 dial-up access, the Update Centre machines were also connected to special modems that handled online bulk updating by IPs. Banks of 300/300 bit/s full-duplex asynchronous V.21 modems supported direct IP-computer-to-Prestel-computer links, while 1200 bit/s half-duplex V.23 modems supported access by IPs using editing terminals that stored frames offline before uploading them. In addition, twin 9-track NRZI tape decks of 800 bytes/inch capacity were provided for bulk offline updates.{{rp|131}}

File:GEC4000computerRoom.png

Though categorised as a minicomputer, GEC 4000 series machines were large: one occupied several standard computer cabinets each standing {{convert|6|ft|m}} high by {{convert|2|ft|m}} wide. The CDC 9762 hard disc drives were housed separately in large, stand-alone units about the size of a domestic washing machine.{{refn|group=lower-alpha|The 70 Mbyte capacity hard discs were removable. Each consisted of a stack of five, {{convert|14|in|adj=on|cm}} diameter platters, standing {{convert|4|in|cm}} high, that could be lifted in and out of the drive unit.}} A GEC machine cost over £200,000 at standard prices, in addition to which were the costs of the associated communications equipment. Combining the two to assemble a single IRC was a major undertaking, and took some 15 months from order placement to commissioning.{{rp|132}}

GEC 4000 series computers could run on several operating systems. The Prestel machines used OS4000, which was developed by GEC and supported BABBAGE, the high-level assembler in which all Prestel software was written.

The pilot-trial system had five core software components: {{sc|input}} process, {{sc|output}} process, {{sc|gate-keeper}} process, {{sc|disc}}-handler process, and several {{sc|task}} processes. {{sc|input}} received data from a Prestel user; {{sc|gate}} accepted characters, one at a time, from {{sc|input}} and fed them to a {{sc|task}}; the key frame-getter {{sc|task}} fetched a fresh page or the next frame of an already-displayed page from {{sc|disc}}. {{sc|output}} then displayed a whole frame, preceded by a clear-screen command, to the user.

{{

cite book

|editor-first=Rex

|editor-last=Winsbury

|editor-link=Rex Winsbury

|title=Viewdata in Action : a Comparative Study of Prestel

|date=1981

|publisher=McGraw-Hill

|location=London

|first=Keith

|last=Clarke

|chapter=The design of a viewdata system

|pages=33{{ndash}}55

|chapter-url=https://archive.org/details/viewdatainaction0000unse/page/33/mode/2up?view=theater

|isbn=978-0-070-84548-0

|oclc=715473323

|url=https://archive.org/details/viewdatainaction0000unse

|url-access=registration

|access-date=18 November 2024

}}{{rp|43{{ndash}}52}}

The commercial service had several important additional functions, including an editing program and bulk update facilities, closed user groups,{{refn|group=lower-alpha|name=CUG}} messages, user billing and IP revenue allocation, optional additional user passwords, error-reporting routines, system manager facilities, and statistics-collecting routines.{{rp|52{{ndash}}53}}

In 1987, a Prestel Admin computer was introduced to support the user registration process. It captured a new user's details from the paper Prestel application form, transferred the data to the relevant Prestel computer, and then printed the welcome letter to be sent to the user concerned.{{refn|group=lower-alpha|The Prestel Admin computer, which was also based on GEC 4082 equipment, was the first to be equipped with the 1 Mbyte of memory needed to support the use of the Rapport relational database product supplied by Logica.}}

Users' connections to Prestel were monitored by a device known as VAMPIRE{{snd}}Viewdata Access Monitor and Priority Incident Reporting Equipment. Via private circuits connected to an IRC computer's ports, this produced a continuously updated display on a monitoring screen at the Prestel Regional Centre responsible for an IRC.{{rp|131}} The screen showed a matrix of small squares, each corresponding to a port on an IRC computer. Free ports were green, occupied ones yellow, incoming calls-to-connect by Prestel users were pale blue, and faulty ports red. In this way, the overall status of an IRC machine could be summarised and seen at a glance.

The response time of the Prestel system was measured by a microcomputer-based device known as PET. This monitored frame retrieval times for users and how quickly frame-editing commands issued by IP editors were implemented. PET operated in conjunction with a hardware performance monitor that recorded central processing unit and disk-drive usage.

{{

cite journal

|journal=British Telecommunications Engineering

|issn=0262-401X

|title=Monitoring the Technical Performance of a National Videotex Network

|last1=Cantwell

|first1=B. D.

|last2=Clarke

|first2=K. E.

|last3=Steel

|first3=G. J.

|volume=1

|issue=3

|date=October 1982

|pages=150{{ndash}}154

|oclc=8735559

}}{{rp|152{{ndash}}154}}

Prestel software and knowhow was sold to the state PTTs of several countries, including Austria,

{{

cite news

|newspaper=The Guardian

|date=4 July 1980

|title=Austria joins Prestel buyers

|page=14

|url=https://www.proquest.com/docview/186273649

|id={{ProQuest|186273649}}

}} Australia,

{{

cite news

|newspaper=The Guardian

|date=15 June 1984

|title=Australia goes for Prestel

|first=Peter

|last=Large

|page=18

|url=https://www.proquest.com/docview/186451213/

|id={{ProQuest|186451213}}

}} former West Germany,

{{

cite newspaper The Times

|title=Post Office sells Viewdata system to West Germans

|first=Michael

|last=Brown

|department=Business news

|date=24 August 1977

|page=19

|issue=60090

|column=4

|url=https://www.thetimes.com/tto/archive/article/1977-08-24/19/11.html

|quote=The West German Post Office will be supplied with a duplicate of the Viewdata computer programmes {{sic}} and expertise, and a trial system will be set up with the guidance of the British Post Office.

}}

the then-British colony of Hong Kong,{{rp|7, 8}} Italy,

{{

cite magazine

|magazine=The Prestel Directory

|title=Italy chooses GEC and Prestel

|page=74

|date=1986

|issue=1

|publisher=Directel

|location=Birmingham

|issn=0266-0288

}} Malaysia,

{{

cite newspaper The Times

|title=Malaysia orders GEC videotext system

|first=Clive

|last=Cookson

|department=Business news

|date=26 April 1982

|page=22

|issue=61516

|column=1

|url=https://www.thetimes.com/tto/archive/page/1983-04-26/22.html

}} the Netherlands,{{rp|24}}

Singapore,

{{

cite journal

|journal=British Telecom Engineering

|issn=0262-401X

|title=Prestel for Singapore [press release]

|volume=4

|issue=2

|page=98

|date=July 1985

|oclc=8735559

}} and Switzerland.{{rp|25}} A private telecommunications company, GTE, bought the system in the USA.{{rp|25}}

• {{annotated link|Bildschirmtext}}
• {{annotated link|Micronet 800}}
• {{annotated link|Minitel}}
• {{annotated link|Singapore Teleview}}
• {{annotated link|Telidon}}
• {{annotated link|videotex}}
• {{annotated link|Viewtron}}

{{reflist|group=lower-alpha}}

{{reflist}}

• {{cite journal

|first=Lucinda D.

|last=Davenport

|date=2023

|title=The Viability of Viewdata as a Mass Medium: A Case Study of Prestel, the Prototype for Computerized Information Systems, the Internet

|journal=TMG Journal for Media History

|issn=1387-649X

|volume=26

|issue=2

|pages=1{{ndash}}29

|doi=10.18146/tmg.845

|doi-access=free

}} Examines the development, marketing, and public reception of Prestel within the digital platform economy emerging at the time.

• {{cite book

|first=Tom

|last=Lean

|title=Electronic dreams: how 1980s Britain learned to love the computer

|date=2016

|publisher=Bloomsbury Sigma

|location=London

|chapter=Chapter 6: Two Information Revolutions That Weren't

|chapter-url=https://books.google.com/books?id=RNaHCgAAQBAJ&pg=PA143

|pages=143{{ndash}}174

|isbn=978-1-47291-833-8

|oclc=944121056

|url=https://books.google.com/books?id=RNaHCgAAQBAJ

}} The chapter covering Prestel describes its history in the context of the 1980s boom in Britain of home computing, and has a particular focus on marketing strategies.

• {{cite book

|first=Raymond

|last=Williams

|author-link=Raymond Williams

|editor-first=Ederyn

|editor-last=Williams

|editor-link=Ederyn Williams

|title=Television: Technology and Cultural Form

|edition=2nd (reprinted)

|date=2010

|orig-date=1st ed. 1974, 2nd ed. 1990

|publisher=Routledge

|location=London

|isbn=978-0-415-31456-5

|oclc=846446460

}} Surveys the social history of television as a developing technology and the social history of how what was developed was used; anticipates{{snd}}from a mid-1970s perspective{{snd}}potential innovations (including "interactive devices"); and provides an overview of the situation in 1990.

• {{cite thesis

|first=Dorian James

|last=Rutter

|date=2005

|title=From Diversity to Convergence: British Computer Networks and the Internet, 1970{{ndash}}1995

|chapter=Chapter 4: Before the Internet: the Rise and Fall of Prestel

|pages=105{{ndash}}158

|chapter-url=https://wrap.warwick.ac.uk/id/eprint/1197/1/WRAP_THESIS_Rutter_2005.pdf#page=131

|degree=PhD

|publisher=University of Warwick

|url=https://wrap.warwick.ac.uk/id/eprint/1197/1/WRAP_THESIS_Rutter_2005.pdf

|oclc=93065596

}} Analyses the evolution of British computer networks and the Internet between 1970 and 1995, with the Prestel chapter focusing on Prestel's communications infrastructure, how this enabled the services offered, and marketing decisions and campaigns.

• {{cite book

|editor-first=Rex

|editor-last=Winsbury

|editor-link=Rex Winsbury

|first1=Alex

|last1=Reid

|first2=Keith

|last2=Clarke

|first3=Robbie

|last3=Robbie

|display-authors=2

|title=Viewdata in Action : a Comparative Study of Prestel

|date=1981

|publisher=McGraw-Hill

|location=London

|isbn=978-0-070-84548-0

|oclc=715473323

|url=https://archive.org/details/viewdatainaction0000unse

|url-access=registration

}} This multi-authored work covers relations between the interest groups involved in providing a videotex service on Prestel, videotex's impact on the press, editorial issues, economic aspects, and likely technological developments.

• {{cite book

|first=Rex

|last=Winsbury

|author-link=Rex Winsbury

|title=The Electronic Bookstall : Push-button publishing on videotex: a critical study of Prestel in Britain

|date=1979

|publisher=International Institute of Communications

|location=London

|isbn=978-0-904-77610-2

|oclc=5507588

|url=https://archive.org/details/electronicbookst0000wins

|url-access=registration

}} Focuses on the practicalities and economics of creating information on Prestel, and on Prestel's relationships with the British newspaper and broader print publishing industry of the late 1970s.

• {{cite book

|first1=Samuel

|last1=Fedida

|author1-link=Samuel Fedida

|first2=Rex

|last2=Malik

|title=The Viewdata Revolution

|date=1979

|publisher=Associated Business Press

|location=London

|isbn=978-0-852-27214-5

|oclc=6387998

|url=https://archive.org/details/viewdatarevoluti0000fedi/

|url-access=registration

}} Co-authored by one of Prestel's inventors, Samuel Fedida, this describes the genesis and context of viewdata, the components of the initial Prestel service, and potential developments from the perspective of 1979.

• [https://archive.org/details/creativecomputing-1983-05./page/n127/mode/2up?view=theater A User's View of Prestel] in an archived copy of Creative Computing magazine

• [https://www.viewdata.org.uk/index.php?cat=15_Prestel Prestel] at Celebrating the Viewdata Revolution

• Objects catalogued under [https://collection.sciencemuseumgroup.org.uk/search/categories/telecommunications?q=prestel "telecommunications /Prestel"] and [https://collection.sciencemuseumgroup.org.uk/search/categories/computing-&-data-processing?q=prestel "computing & data-processing /Prestel] in the Science Museum Group's collections

• [https://www.digitalarchives.bt.com/CalmView/Overview.aspx?src=CalmView.Catalog&r=(((Title=%27Prestel%27))) Catalogue records with "Prestel" in the title] in BT Group's digital archives

{{Videotex}}

{{BT Group}}

{{Telecommunications industry in the United Kingdom}}

{{Telecommunications}}

Category:BT Group

Category:History of telecommunications in the United Kingdom

Category:Legacy systems

Category:Pre–World Wide Web online services

Category:Videotex