Prestel (abbrev. from
press telephone), the brand name for the UK Post Office's
ViewdataViewdata is a Videotex implementation. It is a type of information retrieval service in which a subscriber can access a remote database via a common carrier channel, request data and receive requested data on a video display over a separate channel. The access, request and reception are usually...
technology, was an interactive
videotexVideotex was one of the earliest implementations of an "end-user information system". From the late 1970s to mid-1980s, it was used to deliver information to a user in computer-like format, typically to be displayed on a television.Videotex in its broader definition can be used to refer to any...
system developed during the late 1970s and commercially launched in 1979.
Initial developers
The innovations on which it was based were credited to Samuel Fedida at the then
Post Office Research StationThe Post Office Research Station at Dollis Hill, London, was first established in 1921 and opened by Prime Minister Ramsay MacDonald in 1933.In 1943, the world's first programmable electronic computer, Colossus Mark 1 was built by Tommy Flowers and his team, followed in 1944 by nine Colossus Mark...
in
MartleshamMartlesham is a village in Suffolk, England about two miles South-West of Woodbridge and East of Ipswich. It is often referred to as "old Martlesham" by locals in order to distinguish this old village from the much more recent Martlesham Heath development...
,
SuffolkSuffolk is a non-metropolitan county of historic origin in East Anglia, England. It has borders with Norfolk to the north, Cambridgeshire to the west and Essex to the south. The North Sea lies to the east...
. In 1978 a team of programmers was recruited from within the Post Office Data Processing Executive. Under the management of David Wood they developed the software for the public access Prestel system. In 1983 as privatisation of British Telecom loomed the staff of the software development team were moved into the Prestel Division of BT.
How it worked
In common with the
CeefaxCeefax is the BBC's teletext information service transmitted via the analogue signal, starting in 1974 and running until 2012....
and
ORACLEORACLE was a commercial teletext service first broadcast on ITV in 1974 and later on Channel 4 in the United Kingdom, finally ending on both channels at 23:59 GMT on 31 December 1992....
teletextTeletext is a television information retrieval service developed in the United Kingdom in the early 1970s. It offers a range of text-based information, typically including national, international and sporting news, weather and TV schedules...
services provided by the
BBCThe British Broadcasting Corporation, usually referred to by its abbreviation as the "BBC", is the longest established and largest broadcaster in the world...
and
ITVITV is a public service network of British commercial television broadcasters, set up under the Independent Television Authority to provide competition to the BBC. ITV is the oldest commercial television network in the UK...
televisionTelevision is a widely used telecommunication medium for transmitting and receiving moving images, either monochromatic or color, usually accompanied by sound. "Television" may also refer specifically to a television set, television programming or television transmission...
companies, the system used a modified television to display information in a non-scrolling window of 40x24 text characters, with some simple graphics, conforming to the 1981
CEPT1CEPT1 was a standard set in 1981 by the European Conference of Postal and Telecommunications Administrations for the display of Videotex. Otherwise known as "E1". Published under the reference T/CD 06-01 in May 1981....
standard. Unlike the restricted number of pages available on Ceefax and Oracle, Prestel offered an extensive range of information that had been supplied both by a Prestel department at the Post Office and by third-party information providers.
The range of Information Providers (or IPs) was wide, including: news services, travel companies (serving both the public and travel agents), estate agents, banks and financial services, those providing stock market information, the
governmentA government is the body within a community, political entity or organization which has the authority to make and enforce rules, laws and regulations.....
and
ParliamentA parliament is a legislature, especially in those countries whose system of government is based on the Westminster system modeled after that of the United Kingdom. The name is derived from the French parlement, the action of parler : a parlement is a discussion. The term came to mean a meeting at...
. The IPs entered their information on a central Update Computer, "Duke", located in London. The information was distributed, via an early X.25 packet switching network, to a number of "Information Retrieval Centres" (IRCs) that were distributed throughout the UK, each of which maintained a mirrored copy of the central database.
These IRC machines, located in major telephone exchanges, were known by code names such as "Dryden", "Kipling", "Derwent", "Enterprise", "Dickens", "Keats", "Bronte", "Eliot" and "Austen" (among others). It was the IRC computers that were accessed, at local phone-call rates, by the "ordinary" users retrieving pages of information.
Each page was divided into a series of screen-sized blocks. The user could retrieve the next block of a page by pressing the "#" key. Each block could have up to ten links to other pages. The reader accessed the linked pages by using the digits "0" to "9" on their keypad. They could also issue commands from a limited repertoire known as "star commands" as each was prefixed by the "*" key. For example "*#" meant "go back to previous block (or page)" and "*123456#" meant "go directly to page number 123456". Hence with only a numeric key pad (and no mouse) a user could navigate a web of pages, much as, in the present day, people navigate the World Wide Web.
Access was open to all users except for pages that were allocated to a number of CUGs (Closed User Groups). Membership of each CUG was controlled by the relevant Information Provider. This was usually to run a subscription-paid userbase, such as Farmlink, specialising in agricultural information for the farming community. Mail was handled by a machine known as "Pandora".
All of the Prestel computers (both the Central Update machine and the IRC machines in the telephone exchanges) were
GEC 4000 seriesThe GEC 4000 was a series of 16/32-bit minicomputers produced by GEC Computers Ltd. of the UK during the 1970s, 1980s and early 1990s.- History :...
minicomputers running
OS4000OS4000 is a proprietary operating system introduced by GEC Computers Limited in 1977 as the successor to GEC DOS, for its range of GEC 4000 series 16-bit, and later 32-bit, minicomputers...
, and the Prestel software was written in
BabbageBabbage is the high level assembly language for the GEC 4000 series minicomputers. It was named after Charles Babbage, an English computing pioneer.- Example :
PROCESS CHAPTER FACTORIALENTRY LABEL ENTRYPOINT...
high-level assembly language. Typically an IRC with 1Mb of main memory would support up to 256 simultaneous users sessions.
Public take-up of the service
Whilst teletext services were provided free of charge, and were encoded as part of the regular television transmissions, Prestel data was transmitted via
telephoneThe telephone is a telecommunications device that transmits and receives sound, most commonly the human voice. It is one of the most common household appliances in the developed world, and has long been considered indispensable to business, industry and government...
lines to a
set-top boxA set-top box or set-top unit is a device that connects to a television and an external source of signal, turning the signal into content which is then displayed on the television screen.- History :...
terminal, and while this enabled interactive services and a crude form of
e-mailElectronic mail, often abbreviated as email or e-mail, is a method of exchanging digital messages, designed primarily for human use...
to be provided, it also involved purchasing a suitable terminal, and paying both a monthly subscription and the cost of local telephone calls. On top of this, some services (notably parts of
Micronet800Micronet 800 was an information provider on Prestel, aimed at the 1980’s personal computer market. It was an online magazine that gave subscribers computer related news, reviews, articles and downloadable telesoftware....
) sold content on a paid-for basis. Each Prestel screen carried a price in pence in the top right-hand corner. Single screens could cost up to 99p.
The original idea was to persuade consumers to buy a modified television set with an inbuilt modem and a keypad remote control in order to access the service, but no more than a handful of models were ever marketed and they were prohibitively expensive. Set-top boxes were pioneered by the
Nottingham Building SocietyNottingham Building Society is a building society founded in 1849 by a group led by Samuel Fox , a Quaker and prominent local grocer...
for its customers, who could make
financial transactionsOnline banking allows customers to conduct financial transactions on a secure website operated by their retail or virtual bank, credit union or building society.-Features :...
via Prestel.
The access situation improved as home computers became more commonplace, and by the late 1980s it was possible to use a machine such as a
BBC MicroThe BBC Microcomputer System, or BBC Micro, was a series of microcomputers and associated peripherals designed and built by Acorn Computers for the BBC Computer Literacy Project, operated by the British Broadcasting Corporation...
or
AtariAtari is a corporate and brand name owned by several entities since its inception in 1972. It is currently owned by Atari Interactive, a wholly owned subsidiary of the French publisher Infogrames Entertainment SA ....
computer, equipped with a 1200/75 baud modem and some simple software, to access the Prestel service. Even the more gaming-orientated Sinclair
ZX SpectrumThe ZX Spectrum is an 8-bit personal home computer released in the United Kingdom in 1982 by Sinclair Research Ltd. Referred to during development as the ZX81 Colour and ZX82, the machine was launched as the ZX Spectrum by Sinclair to highlight the machine's colour display, compared with the...
had a large number of users via a low-cost modem called the VTX-5000. It was possible to buy downloadable content such as simple games. This would be encoded in a series of pages that were not human-readable, but encoded in blocks of rather less than 1
kilobyteThe kilobyte is a unit of digital information storage equal to either 1,000 bytes or 1,024 bytes , depending on context....
per page. The header and footer of these pages was normal, however, so users could watch the pages appearing one after another to build up the downloaded file. To charge for content, generally the final pages of the downloaded file were charged at up to 99p each, the maximum possible page price on Prestel. By charging at the end of the download, problems with aborted downloads being charged for were generally avoided.
Because the communication over telephone lines did not use any kind of error correction protocol, it was prone to interference from line noise which would result in garbled text. This was particularly problematic with early home modems which used
acoustic couplerIn telecommunications, the term acoustic coupler has the following meanings:# An interface device for coupling electrical signals by acoustical means—usually into and out of a telephone instrument....
s, because most home phones were hard-wired to the wall at that time.
However, it was still an expensive proposition, and as a result, Prestel only ever gained a limited
market penetrationMarket penetration is one of the four growth strategies of the Product-Market Growth Matrix defined by Ansoff. Market penetration occurs when a company enters/penetrates a market with current products. The best way to achieve this is by gaining competitors' customers...
among private consumers, achieving a total of just 90,000 subscribers, with the largest user groups being
Micronet800Micronet 800 was an information provider on Prestel, aimed at the 1980’s personal computer market. It was an online magazine that gave subscribers computer related news, reviews, articles and downloadable telesoftware....
with 20,000 users and Prestel Travel with 6,500 subscribers.
The costs for businesses interested in publishing on Prestel were also expensive. A basic IP (Information Provider) package with just 100 frames (75K of text) cost £5,500 per annum in 1982. (Nearly £15,000 in 2008 based on RPI.) This ensured that only the largest or most forward thinking companies were interested in the service.
The BT Prestel software development team developed a number of national variants of Prestel, all of which ran on
GEC ComputersThe GEC 4000 was a series of 16/32-bit minicomputers produced by GEC Computers Ltd. of the UK during the 1970s, 1980s and early 1990s.- History :...
. They were sold to the PTTs of other countries, including Austria, Belgium, Italy, Hungary, Hong Kong, Germany, Netherlands, Singapore, Yugoslavia, [incomplete list]. Italy was the largest system with 180,000 subscribers. The Singapore system had a notable technology difference in that pages were not returned over the modem connection, but were returned using
teletextTeletext is a television information retrieval service developed in the United Kingdom in the early 1970s. It offers a range of text-based information, typically including national, international and sporting news, weather and TV schedules...
methods over one of four TV channels reserved specially for the purpose, which had all scan lines encoded in teletext format. This higher bandwidth enabled use of a feature called
Picture Prestel which was used to carry significantly higher resolution pictures than were available on other Prestel systems.
In 1990, BT introduced a new commercial model which effectively killed the domestic usage of the service, charge per-minute charges for access on top of the user's existing phone bill. Finally in 1991 it was decided that BT should move away from providing Value Added Services and should focus on network provision. Consequently the various consumer and business services were run down or sold off with such services as Prestel Travel and BTIS (BT Insurance Service) becoming private network services for third-party providers.
The 1984
hackerIn common usage, a hacker is a person who breaks into computers, usually by gaining access to administrative controls. The subculture that has evolved around hackers is often referred to as the computer underground...
intrusion into the (very likely unused) Prestel mailbox of the
Duke of EdinburghThe Prince Philip, Duke of Edinburgh is the husband of Queen Elizabeth II. Philip was originally a royal prince of Greece and Denmark, and thus a member of the Danish-German House of Schleswig-Holstein-Sonderburg-Glücksburg, but renounced these titles shortly before his marriage and adopted the...
garnered the network some unfavourable press, particularly when the simplicity of its security measures became apparent. The subsequent failure to successfully prosecute the intruders contributed to the introduction of the
Computer Misuse Act 1990The Computer Misuse Act 1990 is an Act of the UK Parliament, introduced partly in response the decision in R v Gold & Schifreen 1 AC 1063 . Critics of the bill complained that it was introduced hastily and was poorly thought out...
.
The Prestel name and equipment was eventually sold by British Telecom, and purchased by a private company,
Financial ExpressThe Financial Express is a daily newspaper published by the Indian Express group since 1961.Launched in 1961, India’s oldest financial daily, The Financial Express, is today one of the leading newspapers in the country...
, in 1994 and renamed
New Prestel. During this period, the platform software was redeveloped onto a SCO Unix and
LinuxLinux is a generic term referring to Unix-like computer operating systems based on the Linux kernel. Their development is one of the most prominent examples of free and open source software collaboration; typically all the underlying source code can be used, freely modified, and redistributed,...
x86 platform away from the GEC 4000 Mini Computers. Additionally, the Citiservice financial data product was successfully redeveloped in house after being outsourced to
DatastreamICV can stand for:* Cargolux Italia, an airline using the ICAO code ICV* Idle Control Valve, a device to control the idle speed of an internal combustion engine.*Integrity check value*Infantry combat vehicle, see Infantry fighting vehicle...
during the time with BT.
Prestel Online, which was an Internet service provider spinoff, was sold to
Scottish Telecom, and as of 5 June 2002, has since been merged into their other ISP activities.
The dial-up viewdata service was run down as the
InternetThe Internet is a global system of interconnected computer networks that use the standardized Internet Protocol Suite to serve billions of users worldwide...
gained in popularity.
Successes
In contrast to the demise of the British system, the
FrenchFrance , officially the French Republic , is a country located in Western Europe, with several overseas islands and territories located on other continents. Metropolitan France extends from the Mediterranean Sea to the English Channel and the North Sea, and from the Rhine to the Atlantic Ocean...
equivalent of Prestel,
Teletel/MinitelThe Minitel is a Videotex online service accessible through the telephone lines, and is considered one of the world's most successful pre-World Wide Web online services. It was launched in France in 1982 by the PTT...
, which used the slightly superior CEPT2 standard, received substantial public backing when millions of Minitel terminals were handed out free to telephone subscribers (causing Alcatel huge financial problems). As a consequence the Teletel network became very popular in France, and remains well used, with access now also possible over the Internet.
A closed access videotex system based on the Prestel model was developed by the travel industry, and continues to be almost universally used to this day by
travel agentsA travel agency is a retail business, that sells travel related products and services to customers, on behalf of suppliers, such as airlines, car rentals, cruise lines, hotels, railways, sightseeing tours and package holidays that combine several products...
throughout the country: see
ViewdataViewdata is a Videotex implementation. It is a type of information retrieval service in which a subscriber can access a remote database via a common carrier channel, request data and receive requested data on a video display over a separate channel. The access, request and reception are usually...
. The Prestel technology was also sold abroad to several countries, and in 1984 Prestel won a UK Queen's Award for Industry both for its innovative technology and use of British products (it largely ran on equipment provided by
GEC ComputersGEC Computers Limited was the computer manufacturing company under the GEC holding company.-History:Starting life as Elliott Automation, the data processing computer products were transferred to ICT/ICL and non-computing products to English Electric as part of a reorganisation of the parent company...
).
Homelink
In 1983 the UK's first
online bankingOnline banking allows customers to conduct financial transactions on a secure website operated by their retail or virtual bank, credit union or building society.-Features :...
service opened with
HomelinkHomelink was the UK's first online banking system. It was set up by the Nottingham Building Society in 1983 in association with the Bank of Scotland, using the UK Post Office's Prestel Viewdata system....
, which was a cooperation between the
Nottingham Building SocietyNottingham Building Society is a building society founded in 1849 by a group led by Samuel Fox , a Quaker and prominent local grocer...
and the
Bank of ScotlandThe Bank of Scotland plc is a commercial and clearing bank based in Edinburgh, Scotland. With a history dating to the 17th century, it is the second oldest surviving bank in what is now the United Kingdom, and is the only commercial institution created by the Parliament of Scotland to remain...
.
See also
- Compunet
Compunet was a United Kingdom based interactive service provider, catering primarily for the Commodore 64 but later for the Commodore Amiga and Atari ST...
- World War II
World War II, or the Second World War , was a global military conflict which involved a majority of the world's nations, including all great powers, organized into two opposing military alliances: the Allies and the Axis...
Colossus computerThe Colossus machines were electronic computing devices used by British codebreakers to read encrypted German messages during World War II. These were the world's first programmable, digital, electronic, computing devices...
, also built by the Post Office Research Laboratories.
External links