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.

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…

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.