Renseignements généraux

Nº de série

2439

Nº de partie

1

Nombre total de parties

1

Ou

S/O

Brevets

S/O

Description générale

METAL CASING & PARTS/ SYNTHETIC PARTS

Dimensions

Remarque : Cette information reflète la taille générale pour l’entreposage et ne représente pas nécessairement les véritables dimensions de l’objet.

Longueur

48,6 cm

Largeur

31,0 cm

Hauteur

11,2 cm

Épaisseur

S/O

Poids

S/O

Diamètre

S/O

Volume

S/O

Lexique

Groupe

Technologie de l'espace

Catégorie

Communications

Sous-catégorie

S/O

Fabricant

Ou

Norpak

Pays

Canada

État/province

Inconnu

Ville

Inconnu

Contexte

Pays

Inconnu

État/province

Inconnu

Période

Inconnu

Canada

This decoder was designed, developed and built in Canada. It is Telidon videotex technology created by the Communications Research Centre. The Telidon program began on August 15, 1978 and ended on March 31, 1985. The decoder was used with an Anik B satellite for a TV Ontario node experiment. This experiment involved four schools in Northern Ontario which provided access for students to databases in Toronto, proving feasibility of providing access to services in remote areas equivalent to those available in urban areas (ref 2).

Fonction

This is a third-generation videotext decoder. The purpose of a decoder is to receive the communications data that's transmitted over narrow bandwidth line, which would be the telephone line in this case, and decode and convert it to something that can be put on to a display screen. This decoder was used to decode Telidon signals sent via Anik B Satellite.

Technique

While this decoder was a third-generation videotext decoder, it was the first generation commercially available. This decoder used a microprocessor and a 1200 baud modem to decode and convert communications data code to something that was displayable on a television display screen. This decoder used a bit plane that is a dot by dot image structure. While the graphic was not high quality, it was quite reasonable and the code was designed to be capable of expanding to handle higher resolutions. The system was designed to be forward and backward compatible, meaning it had the capability of displaying existing and future images, taking advantage of lowering memory costs to improve Telidon technology over time. In 1983, the North American Presentation Level Protocol Syntax (NAPLPS) graphics language develop from the Canadian Telidon system was formalized, ratified and adopted as a world standard for graphics transmission by computer. Developed at the Communications Research Centre, the technology was later transferred to industry, along with key CRC staff, through a contract for a second developmental version (REF 2). According to Douglas O'Brien, systems engineer on the Telidon project, the presence of a switch at the back of this decoder indicates that it would have been used in a lab to test signals. Decoders meant for the home, like artefact 1990.0147, were not equipped with such switches.

Notes sur la région

Inconnu

Détails

Marques

WHITE LETTERING ON FRONT & BACK RESPECTIVELY READING 'Telidon/ norpak' WITH MAPLE LEAF LOGO & 'norpak/ Made in CANADA' WITH LABELS FOR CONTROLS/ ADHESIVE LABELS ON UNDERSIDE READING 'MODEL/ MK3/ SRIAL 2439' & 'norpak/ UNIT MK3' WITH TECHNICAL DATA/ DECAL ON FRONT READING 'VERIFICATION- CRL/ 20914'.

Manque

S/O

Fini

TEXTURED NAVY BLUE CASING TOP & SIDES/ MEDIUM GREY-BLUE CASING FRONT & BACK/ BLACK & WHITE SYNTHETIC BUTTON/ METALLIC & GOLD COLOURED PARTS/ GREY FEET & BLACK POWER CORD/ MULTICOLOUREDSYNTHETIC PARTS.

Décoration

S/O