The CSIR Division of Radiophysics was established in 1939.
Australia's isolation in the Second World War and its need to develop radar systems and microwave vacuum tube technology led in 1939 to the establishment of the CSIR Division of Radiophysics located, along with other divisions, in the grounds of Sydney University.
The Division of Radiophysics, with considerable experience in radar pulse techniques, was well placed to direct some of its resources towards the development of electronic computing. In early 1947, Edward Bowen, Chief of the Division (with prompting from Trevor Pearcey) decided that Radiophysics should enter the field of high-speed electronic computing.
Trevor Pearcey teamed up with Maston Beard and proceeded with the design and construction of the minimum necessary components for an electronic computing system. A third member of the team, Reginald Ryan, who joined the project in 1948, was set the task of building a mercury delay storage system. Pearcey, in collaboration with Geoffrey Hill, then worked on developing a more detailed logic design to facilitate the engineering and fix the instruction set and to devise a practical programming scheme.
About November 1949 (exact date not recorded) the basic units were assembled and the first test-program was run. The result was the first automatic electronic computer in Australia and one of the earliest in the world. This was the CSIR Mk1, later renamed CSIRAC.
First test programs were run in late 1949, and CSIR Mk1 was developed to a stage where it was in restricted operation in late 1950 and was demonstrated during the first Conference on Automatic Computing Machines held on 7-9 August, 1951. One of the demonstrations included a performance of computer generated music.
From 1951 to mid-1955 CSIR Mk1 was employed in the Division of Radiophysics, in part to support the cloud-physics and radioastronomy projects, as well as a tool for developing programming techniques. It also provided a computing service for other divisions of CSIRO, universities, and a variety of other research, design and engineering organisations.
In 1955 the computer was dismantled and transported by road to the University of Melbourne where it was reassembled and on 14 June 1956 formally recommissioned and named CSIRAC.