General Information

Serial #

5585

Part Number

1

Total Parts

1

AKA

N/A

Patents

N/A

General Description

Ceramic disk/ Metal hub, connectors, wiring and parts/ Wood base and arts/ Synthetic wire covering

Dimensions

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

Length

105.0 cm

Width

99.0 cm

Height

N/A

Thickness

8.0 cm

Weight

N/A

Diameter

N/A

Volume

N/A

Lexicon

Group

Computing Technology

Category

Digital computing devices

Sub-Category

N/A

Manufacturer

AKA

Bryant

Country

United States of America

State/Province

Michigan

City

Unknown

Context

Country

Canada

State/Province

Ontario

Period

circa 1967 to1987

Canada

From Bob Plaseski, April 26, 2007: The Collins C-8500 switching computer was installed at CN/CP Telecommunications Headquarters at 151 Front Street in Toronto. Photos of this installation and the C-8500 are on the Canadian Science and Technology Museum’s web site under Communications and Computers – Image CN000012. The disk measures 99 cm in diameter and weighs approximately 30 pounds. It was one of 5 installed in a cage assembly in the C-8500 and spun at a fairly high rpm. The disk is ceramic and has 64 Kbytes of capacity and was written using a hydraulic head assembly. Some evidence of disk crashes can be seen in the ceramic facing. I am not sure as to when the C-8500 was initially commissioned but photographs on your web site are dated 1968. The C-8500 was leased by the Canadian Weather Service and used as a teletype (110-600 baud) switching computer for the collection and distribution of Canadian and international weather data. As Head of National Networks for Environment I ordered the decommissioning of the C-8500 in the late1980s and was given this disk as a memento (Ref. 3).

Function

Medium upon which data and instructions were recorded in the memory device of a main frame computer. The latter was used as a teletype switching computer for the collection and distribution of weather data.

Technical

A large ceramic disk for storing data, part of the first Collins computers in Canada and one of only 12 at the time in North America (the rest being mainly in the US military). This computer was first used by CN/CP and then leased to Weather Canada to process weather data (Ref. 1). The Bryant disc drives used with the Collins C-8500 series of computers were essentially the same as those used with its predecessor, the 8400-series; they first appeared around 1964. At the time of their introduction, they were the largest-capacity moving-head disc stores in existence. The photographs (2007.0224.si1 to 2007.0224.si19) attached to this record are of Disc File 3, one of the last two 8871A-1 units remaining in use at the CNCP Telecommunications Computer Switching Centre (CSC), located at 151 Front Street West in Toronto. The other unit, Disc File 6, can be seen in the background of some of the pictures. The last two "big discs" were scheduled to be de-commissioned on 22 November 1987; they were supplanted by 96-megabyte Data General "Zebra" disc drives, which were interfaced to the Collins C-8500 through a Data General Eclipse S/120 minicomputer, which emulated the timing, buffering, and electrical interface characteristics of the 8871s (Ref 2).

Area Notes

Unknown

Details

Markings

Black lettering reading '5585'

Missing

Unknown

Finish

Brown disk/ Black hub/ Copper coloured and unfinished grey metal parts/ Black synthetic/ Black and grey painted wood

Decoration

N/A