General Information

Serial #

N/A

Part Number

1

Total Parts

12

AKA

N/A

Patents

N/A

General Description

METAL/ SYNTHETIC/ CERAMIC/ GLASS

Dimensions

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

Length

48.0 cm

Width

31.5 cm

Height

9.5 cm

Thickness

N/A

Weight

N/A

Diameter

N/A

Volume

N/A

Lexicon

Group

Computing Technology

Category

Digital computing devices

Sub-Category

N/A

Manufacturer

AKA

Norpak

Country

Canada

State/Province

Ontario

City

Kanata

Context

Country

Canada

State/Province

Ontario

Period

1980'S

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.

Function

This is a fourth-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.

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 mark 4 decoder was a great upgrade because it was developed after the adoption of the NAPLPS standard. It had a significant amount more functionality, including dynamic color maps. It also had the capability of supporting some of the codes that came from the European videotex systema because the Communications Research Centre research team wanted to increase the information economy.

Area Notes

Unknown

Details

Markings

.1 ON FRONT: 'norpak/ Mark IV Telidon Videotex Decoder/ Power CarrierSend Receive Dial'/ ON BACK: 'norpak ltd./ KANATA, ONTARIO/ MADE IN CANADA/ [PORTLABELS:] KEYBOARD/ DATA PORT/ TELEPHONE/ RED GREEN/ BLUE SYNC/ RF IN RF OUT/ [BAUD RATES LISTED]/ [ECHO & DATA CHOICES LISTED]/ [ABOVE PLUG:] 120 VAC/ UNSWITCHED/ 250 W MAX. LOAD/ [ABOVE FUSE:] 120 VAC/ 3 AMP/ SLOWBLOW/ [ABOVE CORD OUTLET:] 120 VAC/ 60 HZ/ 1 AMP'/ STICKER READS: 'ontario hydro/ electrical/ approval/ by special inspection-series 10'/ STICKER ON TOP: 'N.M.C./ M.N.C./ 32145'.

Missing

N/A

Finish

VARIOUS SHADES OF GREY PLUS BLACK WITH BLACK & WHITE PRINTING & TRIM.

Decoration

N/A