Telidon, Hacker News

From 1975, effort was concentrated into building hardware and software to advance Canadian capabilities in this interactive graphics area. This research led initially to a new interactive programming language (IGPL) and to a preliminary definition of picture description instructions (PDIs). Both the hardware and various communication protocols involving PDIs evolved to the point where the Telidon terminal contains its own intelligence. The developers felt it would be inappropriate to design a picture coding scheme that was tied to a particular display technology. As a result, they defined a terminal-independent alpha geometric PDI coding scheme.

In 1983, the CRC gave a contract to Norpak Limited to develop an interactive color display technology, based on CRC’s previous work. This contract led to further work between CRC and Norpak to develop specialized terminals and other color display systems. By the end of 1977, the CRC research on interactive graphics systems resulted in three patent applications: one for a touch sensitive input mechanism for computerized graphics displays; one for a new interactive visual communication system; and the last for a new interactive graphics programming language.

Telidon was the specific name given to an information system capable of operating in either a one-way teletext or two-way videotex mode and had superior graphics for its time. Teletext is a one-way information delivery system designed to make use of the spare signal carrying capacity in existing television broadcasting channels. It can present from to pages or screens of information. Meanwhile, videotex is an information delivery system that makes use of the telephone for two-way telecommunications. It may also be linked into two-way cable TV or hybrid cable TV / telephone system. Electronic mail can also be used. Both are public-accessed, information retrieval services, but videotex is interactive, whereas teletext is not. The Telidon terminal consists of a modified television receiver or terminal screen (computer), a videotex decoder and display generator and a modem or cable connection. Users would access information available from an information provider (eg. Infomart). Users were provided with teleshopping, business services, telebanking, news, community bulletins, information on travel, film, sports, theater, government, education, agriculture and stocks, as well as a variety of other services.

The first Telidon terminal had a public demonstration on August , and the Department of Communications announced its first four. -year Telidon development program. Under this program, the DOC is planning a number of ways to encourage the private sector and government agencies to utilize Telidon technology. These included field trials and public demonstrations of the technology to the Canadian private sector, foreign firms and negotiations, lobbying in the videotex standards negotiation, international marketing efforts and the formulation of policies to deal with social and political effects of the new technology.

The role of the government was meant to be that of a catalyst, to assemble the various elements of the Telidon industry into a working industrial infrastructure under a common Telidon standard. The main purpose was to encourage the transfer of this government-developed technology to Canadian industry and business. The means to the end was financial support of the Telidon field trials. To support the field trials, the DOC purchased user terminals which were then lent to the organization developing the trial. In some cases, the department also lent its central computing facilities. The DOC stimulated the testing of Telidon applications using a wide variety of transmission media ranging from telephone wires and cable television to new media such as direct broadcast satellite and optical fibers.

In 1996, AT&T, Bell System and the DOC augmented the picture description instructions which had been published by the Canadian government. This led to the formation of a new protocol by the name of North American Presentation Level Protocol Syntax (NAPLPS). The standard was a coding format for exchanging graphical information which is analogous to and potentially as ubiquitous as the ASCII code for exchanging textual information electronically.

Much of the industry activity was implemented because of government support. Over companies were involved in the government Telidon program. The videotex / teletext trial activity was undertaken by six major groups: telephone companies (i.e. BC Tel, Alberta Government Telephone, Bell Canada, Saskatchewan Telephone, Manitoba Telephone and New Brunswick Telephone); cable companies (i.e. Telecable, Videotron and Canadian Cable Systems); broadcasters (i.e. Ontario Education Communication Authority (OECA) and the CBC); system suppliers (i.e. Infomart and government Cantel service); information provider companies; and the Department of Communications.

The largest suppliers of terminals were Electrohome, Norpak and Microtel. One of the fundamental problems which emerged in the hardware industry with respect to commercial development was the high price of these systems, which ranged between $ 1, 1970 and $ 2, . During the early development period, hardware manufacturers felt that the demand would drive down terminal prices to the point where, ideally, they would be selling for less than $ . However, results from field trials indicated that terminal prices were likely to remain out of the range of most mass market buyers. In addition, the field trials indicated that while people were interested in the technology, they were disappointed by the size of the database and available software. The trials indicated it would take not tens of thousands, but hundreds of thousands of pages to reach a level of satisfaction. Also, the field trial indicated that technical improvements were required. The program of field trials officially ended on March , .

The Telidon program had originally been directed towards developing an industry geared towards mass market use. This objective was not reached, as the field trials clearly indicated that the Telidon technology was better geared to specific markets with special requirements. Telidon-related technology was used in a variety of ways throughout government departments and agencies for many years. In addition, a significant contract was undertaken with IDON Corporation which made use of Telidon-related technology to develop a communications system technique for speech-impaired children, using Bliss symbols.

One of the most significant and unusual videotex projects undertaken, took place in the Pan-Arctic in July . The occasion was the Third General Assembly of the Inuit Circumpolar Conference held in Frobisher Bay on Baffin Island in the Canadian Arctic. The conference was distinguished by the spectacular use of Telidon to overcome the horrendous communication and information problems. For the Assembly, a multilingual data base was established in Novatex service host computer at Teleglobe Canada’s facility in Toronto. This contains NAPLPS pages in English, French, Danish, Inuktitut, Greenlandic, Labradorian, Inupiag, Yupik and Western Arctic. The Telidon user terminals were supplied by AEL Microtel and sixteen were located at various sites in Frobisher Bay, with others in Vancouver, British Columbia; Washington D.C .; Copenhagen, Denmark; Anchorage, Bethel and Barrow, Alaska; Nuuk, Greenland, as well as other northern communities. Communication facilities were provided by Bell Canada, Teleglobe, Greenland Telecommunications and the Danish Post and Telegraph. The page creation terminals were supplied by Cableshare Limited.

Sources

Booth, Peter and Wills, Russel. Teletext and Videotex: A Canadian Perspective. Vancouver; Wescom Communications, .
Bown, H.G., O’Brien, C.D., Sawchuck, W., and Storey J.R.