Monday, September 15, 2008

BPN 1221 Pre-internet (7): Videotex, tree content

Videotex content
Videotex differs from ASCII in presentation and linking. Videotex is a presentation protocol and not a communication protocol like ASCII. While in ASCII the rules fill the screen from the top, videotex presents the information as a page. All those pages are like a mobile artwork from the ceiling, but a mobile with nine levels. The top two levels (0 to 9 and 01 to 99) were destined for system activities. The third level (001 to 999) was intended for starting pages. An information provider could use six levels to distribute his/her information. Every page could expanded with add-on pages from a to z. Via a tree menu one could search for information and by keying in page numbers one could reach a page directly; in this way it was possible to use the system for timely information by keying in a date like 800915 (15 September 1980). In this way it was also possible to search sideways. Searching like in ASCII databases by keywords was not possible, unless the information provider put up a list of controlled keywords as links.

Illustration of tree structured pages:
- top two systems levels;
- level three is starting page;
- information pages;
- add-on pages.

Every page had 24 rules of 40 positions (letters, figures, symbols and diacritical signs). Every position was built up in a small mosaic of sic squares, which could be used to produce rudimentary graphical representations such as cars (with square wheels). Text as well as graphical representations could be embellished with one of seven colours (white, black, green, blue, red, yellow, magenta).

The page orientation entailed consequences for the writing of content. The author was limited in text by the space of a page and always had to think about navigation. Every page needed links to go back to the level above or to the starting page as well as the exit page (which was hardly used), but there was also a need to lead the user in the navigation from top to bottom, from the bottom pages up as well as sideways by using index pages (see illustration).

Videotex was seen as a consumer information system. The first British Prestel system contained 16 sections:

Buying a Car------Financial Information
An Evening Out -- Market Intelligence
Houses for Sale---Business Intelligence
Local Information-Community Services
Social Guidance---Route Planning
Looking for a Job-Holiday Information
Education---------Sports Results

Source: The Viewdata Revolution by Sam Fedida and Rex Malik; Associated Business Press, 1979

The organisation of the videotext service was similar to the ASCII database service, except that the videotext services in the eighties were claimed by the national mail and telephone services as an extra service and source of revenues. In the UK the British post office claimed the service, in The Netherlands the Dutch PTT, in West-Germany the Bundespost and in France the French PTT.
But soon there came a difference between the organisation of the service following the British Prestel model and the French kiosque model. In the Prestel model the PTT controlled the system, did the marketing and publicity and handled the revenues on behalf of the information providers. The PTTs even got involved, for the first time, in content for the first time by claiming the common index and keyword maintenance.
The French PTT was less in control and left the content business to the information providers and publishers. The French PTT was involved with maintaining the system and the network as well as handling the revenues. But the information provider and publishers were more independent in setting up their services, including the technical side. They could link their own computer to the central computers and use the service like a newspaper kiosque, promoting their own products. This has been a key success factor in the promotion of the French Teletel project.

Blog Posting Number: 1121

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