Computer operator stands in front of CSIRAC, which has it doors open revealing cables and electronic connections.

CSIRAC covered more than 10 square metres of floor space and weighed seven tonnes.

CSIRAC: Australia’s first computer

CSIRAC was built by CSIR in 1949 and it was the fourth computer in the world - it completed more than 1 000 projects by the time it was turned off in 1964.

  • 3 June 2005 | Updated 14 October 2011

Australia's first computer, CSIR Mark 1 (later called CSIRAC, the CSIR Automatic Computer), was the fourth in the world to be built. It filled a room the size of a double garage, required enough electricity to power a suburban street and had only a fraction of the brainpower of the cheapest modern electronic organiser. But it was a technological marvel of its time.

Before the invention of computers, scientists would perform complex calculations by hand or with the aid of a mechanical adding machine. Calculations could be done at the rate of about one operation per second.


In the late 1940s CSIR scientists Dr Trevor Pearcey, Mr Maston Beard and Mr Geoff Hill built a digital computer called CSIR Mark 1, which put Australia at the forefront of computing. It revolutionised everything from weather forecasting to banking. It even played what is thought to be the first ever computer music. CSIR Mark 1 was renamed CSIRAC and ran its first program late in November 1949.

Once fully operational, CSIRAC was a thousand times faster than anything else available in Australia at the time.

Improvements were steadily made to the computer in the early 1950s at the Radiophysics Laboratory in Sydney.

It buzzed the world's first digital music, Colonel Bogey, to an international audience during Australia’s first computer conference in June 1951.

CSIRAC processed more than 1 000 computing projects in fourteen years.

CSIRAC provided a computing service to all of CSIRO from 1951 to 1955. During this time it was used for over 300 projects.

In 1956 the improved CSIRAC Mark II was dismantled, loaded on trucks and driven down the Hume Highway to the University of Melbourne.

For the next eight years CSIRAC processed more than 700 computing projects during about 30 000 hours. These projects ranged from calculating home-loan repayments for the University of Melbourne staff members to helping to design skyscrapers.


CSIRAC's historical significance was finally realised in 1964 when it was noted that CSIRAC was the world's oldest computer still in operation. The University of Melbourne had purchased an IBM 7044 that year and CSIRAC, deemed worthy of preservation, was carefully dismantled and stored.

CSIRAC is now the centrepiece of the Information Technology (IT) display at the Museum of Victoria in Melbourne and is the world's oldest existing stored-memory electronic computer.

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