Canada Systems Group (CSG) was one of the first data processing service bureaus in Canada. Featuring IBM and Amdahl mainframes, disk and network processors, alongside StorageTek tape devices, CSG was the largest, followed by Datacrown, whose owner at the time was Crown Life Insurance, and IP Sharp (eventually acquired by Reuters, now Thomson Media). Canada Systems Group (EST) Limited was a data processing service bureau based in Mississauga, Ontario, Canada. Key dates October 1970 - CSG created by Eatons, Stelco & London Life with office in TD Tower Floor 37, Toronto Spring 1971 - Office moved to Sheridan Mall, Mississauga September 1971 Labour Day - Office moved to 2599 Speakman Drive, Mississauga, Ontario. Mid November 1971 - Stelco production started at Speakman Late January 1972 - Eatons production started at Speakman History CSG was originally created by the divestiture of the data processing departments of Eaton's, (Canada's largest department store chain), Stelco (Canada's largest steel producer), and TRW. The latter company dropped out of the triumvirate shortly after CSG was formed, to be replaced by Royal Trust, Canada's largest Trust company. CSG's head office and main datacentre was located in the Sheridan Park Research Community in Mississauga Ontario. CSG maintained smaller datacentres in Ottawa, Ontario and Calgary, Alberta. Sales offices were maintained in Vancouver (BC) Calgary (AB), Edmonton (AB), Winnipeg (MA), Toronto (ON), Montreal (PQ), Saint John (NB) and Washington, DC (USA). Early in its history, CSG acquired Multiple Financial Services, a financial service bureau, at time the largest in Canada, which provided outsourcing of the processing and accounting functions for the brokerage and mutual funds industries. The Mississauga datacentre was one of the largest in North America, consisting of two raised floorspaces of each. The second floor housed the multiple mainframe processors and hundreds of disk units. The first floor housed the network processors, switches, and utilized the first fibre-optic cables available in Canada. In addition, over 200 tape drives, a tape library of over one hundred and thirty thousand serial tape volumes on moveable shelves before disk-packs began to overtake tape data storage and the main console areas (the 'Dais') were on the first floor. To achieve the required efficiencies, CSG developed its own Pre-Scan software for the IBM MVS Operating System. This software facilitated tape drives being pre-allocated and tape files pre-mounted by tape operators as a job was read into the job scheduler. Two Job Execution