General Information

Serial #

6728

Part Number

1

Total Parts

2

AKA

N/A

Patents

N/A

General Description

METAL/ SYNTHETIC

Dimensions

Note: These reflect the general size for storage and are not necessarily representative of the object's true dimensions.

Length

48.5 cm

Width

29.0 cm

Height

9.0 cm

Thickness

N/A

Weight

N/A

Diameter

N/A

Volume

N/A

Lexicon

Group

Computing Technology

Category

Digital peripheral devices

Sub-Category

N/A

Manufacturer

AKA

Norpak

Country

Canada

State/Province

Ontario

City

Kanata

Context

Country

Canada

State/Province

Unknown

Period

1982-1985

Canada

This decoder is part of Canadian designed, developed and built Telidon videotex technology created by the Communications Research Centre. The Telidon program began on August 15, 1978 and ended on March 31, 1985.

Function

This is a third-generation videotext decoder used to decode Telidon graphics images. The purpose of a decoder is to take the communications data that's transmitted over narrow bandwidth line, which would be the telephone line in this case, and convert it to something that can be put on to a display screen in the family home.

Technical

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. The Norpak Mark 3 decoder was broadly distributed as part of the field trials. It used a fixed color map in order to cut purchase cost.The board is was designed around was also used in other Telidon terminals like Electrohome TELCO-R-NK. It is beleive that the Mark 3A used different software that the Mark 3 decoder.

Area Notes

Unknown

Details

Markings

BACK PANEL - 'norpak/ Made in CANADA/ NO USER SERVICEABLE/ PARTS INSIDE./ 120 VAC/ 60HZ/ 160W/ UNSWITCHED/ 100 WATTS MAX/ 3 AMP/SB/ COMM/ KPD/ KBD/ SYNC XPAR TX RED GRN BLU/ VIDEO'/ CSASTICKER: 'CSA/ LR 49159/ MODEL TLD-MK3/ SERIAL'/ FRONT: 'Telidon/ norpak'

Missing

N/A

Finish

BLACK WITH WHITE PRINTING

Decoration

FRONT PANEL HAS 4 BANDS OF WHITE WITH MFR'S NAME OVER A MAPLE LEAF