May 25, 2022

Trevor Pearcey: Australia’s computing pioneer

In the late 1940s and into the ’50s, Australia was at the international forefront of computer design and construction. One of the key figures was expatriate British scientist Trevor Pearcey.

Pearcey was born in London in 1919 and graduated from Imperial College London in 1940 with first-class honours in physics and mathematics. He emigrated to Australia in late 1945 to work at the radiophysics division of the Council for Scientific and Industrial Research (CSIR), which in 1949 became today’s Commonwealth Scientific and Industrial Research Organisation (CSIRO).

A biography of Pearcey published by the CSIRO says that while still in London he’d stopped his PhD studies during the Second World War and joined the Air Defence Research Development Establishment.

Upon arrival in Australia he was put to work on radar systems, but in 1946 began “to formulate the logical planning for an ‘Automatic Computer’”.

The planning, design and operation of this computer is described in the 2000 book The Last of the First – CSIRAC: Australia’s First Computer, by Doug McCann and Peter Thorne.

“In the late 1940s, Australian scientists embarked on an ambitious project to design and build, from the ground up, a programmable digital computer,” they write. “They succeeded. The computer they created was not only the first computer in Australia, it was one of the very first in the world. This was the CSIR Mk1 computer (later renamed CSIRAC). It provided a computing service through the 1950s and well into the 1960s. Furthermore, it survives intact and is now considered to be the oldest survivor of the machines which started the digital revolution.”

Pearcey had seen the behemoth Mark 1 computer built in the United States by Harvard University professor Howard Aiken. A 2011 edition of the Harvard Gazette says the Mark 1 “was the first programmable computer in the US”, which “launched the computer age, introducing automated computation as a tool to address problems in the natural, applied, and social sciences”.

Construction of Australia’s Mk1 computer was undertaken from 1946 to 1948, with Maston Beard in charge of engineering and Pearcey covering the logical design. “This machine, the CSIR Mk1, was developed largely independently of work then underway in Britain and the US,” says the CSIROpedia.

It ran its first program in November 1949 and “was almost certainly the fourth stored-program electronic computer in the world and the first outside Britain and the US”.

In their 2000 book, McCann and Thorne say it is difficult to rank the operational dates of many of these first-generation computers “because much depends on one’s definition of operational.

“These early electronic computers were not regular items of technology, but quite large and expensive pioneering research projects, more like room-sized pieces of custom-built laboratory apparatus than the standardised mass-produced personal computers of today. Once the basic principles were demonstrated to be sound, these machines were gradually and continuously improved.”

McCann and Thorne say a working CSIRAC (still called the Mk1 at this stage) was publicly demonstrated during the first Conference on Automatic Computing Machines, held in Sydney in August 1951. For the next four years, to mid-1955, it was used in the radiophysics division and also provided a computing service for the CSIRO, universities, and various other research, design and engineering organisations, while serving as a tool for developing programming techniques.

As a sidebar to the conference, Pearcey and one of his programmer colleagues, Geoff Hill, demonstrated the Mk1’s ability to play music – possibly the first example of computer music. A built-in speaker was used to alert operators when a particular event had been reached in the program, such as the end of a program or as a debugging aid.

The blog 120 Years of Electronic Music explains that “the output to the speaker was basic raw data from the computer’s bus and consisted of an audible click. To create a more musical tone, multiple clicks were combined using a short loop of instructions; the timing of the loop giving a change in frequency and therefore an audible change in pitch.”

It says the music created by Hill and Pearcey was meant “as a way of testing the machine rather than a musical exercise”. The first piece was “Colonel Bogey March”.

Despite a record of seemingly successful operation, on 13 April 1954 the Mk1 project “was officially terminated”, McCann and Thorne say. “Pearcey later lamented that a major Australian project ‘withered from lack of internal interest and supportive imagination’.”

Enthusiasm for the work being done with the computer had waned within the CSIRO, and more importantly, “far less interest was taken in computing, which was seen as a necessary but subordinate aid to other activities”.

“This was not the attitude taken by Trevor Pearcey. It is probably accurate to say that he was acutely aware of the promise and potential of computing as a discipline, a technology and an industry in its own right.”

In mid-1955 the Mk1 was dismantled in Sydney, loaded onto a truck and moved to the physics department at the University of Melbourne, where, in June 1956, it was recommissioned, renamed CSIRAC, and the new computation laboratory at the university was officially opened.

“While other first-generation computers around the world were being shut down and dismantled,” McCann and Thorne say, “CSIRAC at the University of Melbourne began a serviceable second life.” Improvements were made and for the next eight years it “functioned as an open-shop computing service”.

A 2020 article published by says CSIRAC was decommissioned in November 1964. It was donated to Museums Victoria and placed in a warehouse until 1998. “In 2000 it became the centrepiece of the technology gallery at the Melbourne Museum. It remains the oldest surviving first-generation electronic computer still in existence anywhere in the world, complete and in its original state; sadly, while restored in appearance, it is not functional.”

The CSIROpedia calls Pearcey “a visionary”, and cites his comment in a February 1948 article for the Australian Journal of Science as a foreshadowing of the worldwide web: “In the non-mathematical field there is wide scope for the use of the techniques in such things as filing systems. It is not inconceivable that an automatic encyclopaedic service, operated through the national teleprinter or telephone system, will one day exist.”

Pearcey died on 27 January 1998. In that year, the Pearcey Foundation was formed in his memory “as a great Australian ICT (information communication technology) pioneer, to promote the significance of the ICT sector and its ability to positively contribute to the Australian economy.”