Remembering Australia’s first computer 103



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Australia’s first computer weighed two tonnes, filled a large room and had a tiny fraction of the capacity of today’s typical smartphone. But why would such a machine continue to be relevant today?

Originally designed and built by the Council for Scientific and Industrial Research (now known as CSIRO) in Sydney as the CSIR Mk1 in 1947-50, it was one of the very first computers to be completed and is the oldest computer that is still substantially intact.

It was relocated to the University of Melbourne in 1955 and relaunched as CSIRAC (pronounced sigh-rack) on June 14, 1956 (just a few months before Sydney’s SILLIAC, which was launched in September 1956), and operated until 1964. It is now a permanent exhibit at Museum Victoria.

The core design of CSIRAC is still the basis of computers today. It consists of a processor that executes instructions and storage used for both data and sequences of instructions – that is, programs.

The original CSIR Mk 1, later renamed CSIRAC, was constructed by the Division of Radiophysics to the designs of Trevor Pearcey (pictured) and Maston Beard. CSIRO Archives, CC BY

Huge in size, it was tiny in terms of computational capacity. Think of a smartphone as a “unit” (call it a “smart phone unit”, or SPU) of processing size then CSIRAC’s capacity was roughly a millionth of that – a microSPU.

Over its 14 years or so of operating life it did about the work that a smartphone today could do in a minute. Its storage was sufficient for rather less than one second of an MP3 music file.

But in terms of power, weight and size, it was 10,000 times larger, or, overall, ten billion times less efficient than today’s processors. Scaling up CSIRAC’s memory to that of a smartphone would fill the Melbourne Cricket Ground to the brim, and running it would consume all the power generated in Australia.


Since then, computers have changed just a tad…

Old computer



Tell us about the first computer you ever used. How does it compare to the one you use today?

This is an extract from an article in The Conversation. To learn more about Australia’s first computer, click here.

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  1. I am using my new tablet that we bought yesterday. It has a keyboard attached. I love it. I worked in the ANZ Bank 36 years ago when we were preparing to go to computers. We worked a lot of overtime to get the information prepared. My husbands first portable computer was the size of a small suitcase and weighed about 10 kilos. It fitted into the boot of our car. He loved it because he could take it with him when he visited clients.

  2. Fifty years ago I went past a window in Sydney CBD and saw a ‘thing’ the size of a whole room….others were ogling it too…..quite something….love todays neat little packages by comparison

  3. I built my first computer based on circuit published in Electronics Australia magazine. Didn’t have much money so I had to cut down the capabilities. About 1977. (Wish I could date the articles)
    Sinclair ZX 81 which I bought in 1982 far outclassed it. 1K of memory.
    The following year I bought the 16K upgrade which made it far more usable.

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  4. I was at Newcastle University in the late 70s as a (very) mature student. Our psychology lecturer put our statistics assignment on the uni “Vax” computer. Oh dear, I was trying to access the computer and all I got was ” a fatal error has occurred!” Tears, tears ,tears! I did pass the course! X

  5. I remember our High School was among the first to offer Computer studies back in the 1960s. The class was limited to a few of the most intelligent and academic senior boys. The computer like one of these was located across the paddocks of an agricultural school and university and cables ran to the computer classroom I think the actual computer time was limited to about an hour a week. It wasn’t till the late 1970 or early 1980s that we had our first slow and primitive home computer from Dick Smiths.

  6. When I was 16 I started work at Innoxa in Brookvale on an invoicing machine called. Bradma. It used metal plates you slotted in the Bradma and you moved it back and forth to produce invoices. That lasted for about 12 months before I was moved on. Soon after that they built an AC room for the new IBM computer, two staff members were retired and 2 computer trained people were hired. Hilariously my iPad or iPhone is capable of doing more 100times faster than that IBM 40 odd years later!

  7. The company I worked for in 1969 got a new computer and decided that they no longer needed half the office staff, so we were let go.

  8. My first experience with a computer was in 1967 at the local college, it was twice the size of the one illustrated. It used binary code to perform tasks, this was pre dos. How technology has advanced, an incredible achievement.

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