At the dawn of the computer age, Australia was among the world leaders, with a 2.5 tonne behemoth named CSIRAC that broke new ground.
In November 1949, CSIRO scientists in Sydney independently created what is now recognised as only the fourth digital stored program computer in the world: CSIRAC. It came hot on the heels of other first-generation computers created in the UK and the US only a year earlier.
Using vacuum tubes instead of microchips, the noisy behemoth filled a room and consumed enough electricity to power a suburban street. While paltry by today’s standards, CSIRAC was a stunning achievement at the very dawn of the computer age.
“It had a presence like Stonehenge, a scale that was impressive — big grey cabinets filling a room, humming like a power station,” recalled Peter Thorne, who, at the age of 19, began working on CSIRAC in the 1950s; he went on to head up computer engineering at the University of Melbourne.
Before CSIRAC, a “computer” was a job — someone who wrangled equations on a mechanical calculator. Complex calculations would be split into many parts and distributed to individual “computers” — row after row of mathematics graduates (mostly women) who would labour over arithmetic for hours, sometimes days, to complete a single task.
“CSIRAC was 1000 times faster than that, so it was like a super-computer in its day,” Thorne said.
Compared with today’s computers, CSIRAC was piddling. Its main memory, what we would now call its RAM (random access memory), was just two kilobytes — or four million times smaller than a typical laptop with eight gigabytes of RAM. Its long-term data storage was five kilobytes — or 25 million times smaller than the simplest thumb drive you can buy. And its top clock speed, or the speed at which it processed calculations, was one kilohertz, or 1,000 cycles per second. Today’s laptops are measured in gigahertz, or billions of cycles per second.
But for the time, it was an extraordinary piece of engineering, Thorne said.
“We knew we were at the beginning of something wonderful — we just didn’t know how big it would be. We certainly didn’t think that one day we’d have millions of times more computing power on our wrists.”
“It’s an iconic machine globally, and something Australia should be immensely proud of,” said Wayne Fitzsimmons FIEAust, former vice president of Data General.
“It’s miraculous what they were able to achieve. All the parts — valves, relays, wiring, switches, the software, everything — were made locally. It’s the most Australian computer ever built.”
CSIRAC’s remarkable story began in Sydney in 1947, at the Radiophysics Laboratory of CSIR — the Council for Scientific and Industrial Research, forerunner of CSIRO.
Calculations for a range of new applications, from radar to radio astronomy, had become laborious and slow. The physicists and engineers — like others elsewhere in the world at the time — reasoned it was now practical to build a large-scale electronic calculator that could be pre-programmed to handle such hefty mathematical tasks.
So began a grand endeavour to build a massive electronic calculator. Maston Beard, a research engineer at the laboratory, teamed with Trevor Pearcey, a physicist and mathematician who had worked in Britain for many years on the development of shortwave and microwave radar. In 1946, Pearcey began to design a large electronic computation device with a stored memory.
Each element was painstakingly hand-drawn by pencil on large-format plans that later became the machine’s blueprints — reams and reams of them. Finally, in early 1948, construction began; with Beard in charge of engineering and Pearcey the design.
The moment of truth came in November 1949, when the first test program was run: a long multiplication routine. And it worked. Clunky it may seem to us, to its creators it was a marvel: it was able to operate more than 1000 times faster than the best mechanical calculators of the time.
The jubilant team called their metal colossus the CSIR Mark 1 (which was later renamed CSIRAC, for “CSIR Automatic Computer”). It covered 40 square metres of floor space, weighed 2.5 tonnes and, when fired up, consumed 30 kilowatts of power.
Two decades before computer monitors were invented, CSIRAC was using cathode-ray tubes — or small televisions — to display the internal workings of the machine.
It had no mouse or floppy disks: instructions were written on punched paper tape and then fed into the computer via a small feeder wheel. A photo-electric detector would read each line of 12 holes on the spool of paper, row by row. An operator would sit on a ponderous grey metal console covered with toggles, switches and meters.
Once the hour-long testing procedure had been completed, and the paper software loaded, CSIRAC would fire up.
Its row after row of grey metal cabinets covered in dials and gauges would come alive. Coloured lights, dotted in rows along its panels, would blink on and off as it processed its task. Inside the cabinets, jumbles of thick wiring, mercury switches and vacuum tubes — 2000 of them — would do their jobs.
Nevertheless, this seemingly archaic marvel of 1940s technology tackled problems that had hitherto been considered too difficult or laborious. Among them were evaluating designs for the construction of buildings, such as the Reserve Bank Building in Sydney and ICI House in Melbourne — the latter considered an architectural icon of the 1950s.
Electronic music pioneer
In their quieter moments, CSIRAC’s engineers also created computer games, calculated their mortgages and even tried their hand at computer-generated music.
This was in 1951 and, as it now turns out, an historic moment. One of CSIRAC’s programmers was Geoffrey Hill, who came from a musical family and had ‘perfect pitch’, the ability to identify by ear any note and sing a specified musical note at will.
CSIRAC had a rudimentary speaker, or “hooter” as it was known, that would warn operators when a task was complete. Could he program this basic instrument to play a musical melody, Hill wondered.
It was no simple task: pulses needed to be sent to the speaker with a regular and predictable period, in order to achieve a steady and continuous tone.
This was further complicated by the fact that CSIRAC had delay-line memory, and each mercury memory tube had a different access timing. Along with a 1,000-hertz main frequency and a memory limitation of just 768 ‘words’, CSIRAC made the task of playing even the simplest tune extremely difficult. Even so, Hill realised that with effort, rudimentary music could still be played.
He succeeded. At the computer’s first public exhibition in 1951, at the inaugural Conference of Automatic Computing Machines in Sydney, CSIRAC played Colonel Bogey’s March, a popular marching tune from World War II.
Hill went on to program CSIRAC to play other melodies, mostly from popular songs of the day, including Bonnie Banks and The Girl with Flaxen Hair.
It was only in the 1990s that historians realised this light-hearted foray actually made CSIRAC the first computer in the world to play music, according to Paul Doornbusch, a composer and associate dean at the Australian College of the Arts in Melbourne, who specialises in electronic music and has researched the past of both CSIRAC and early computer music.
“The pieces were not as musically inspiring as they might have been if composers had been involved — the achievement was in conceiving of using a computer to make music, as well as the ingenuity required to produce reliable sounds,” Doornbusch said.
“It’s difficult to appreciate today just how skilful these people were.”
A lost legacy
Despite this early lead, the CSIRO decided that computers were “outside its purview”, a decision which left designer Trevor Pearcey deeply disappointed.
In his view, Australia had thrown away a chance to lead the world in digital computing. “We were living off the sheep’s back in those days, so the potential wasn’t recognised,” Fitzsimmons said.
CSIRAC was packed up and moved to the University of Melbourne, where it was used for a decade before being decommissioned and going into storage.
Vacuum tube computers like CSIRAC were quickly overtaken by the arrival of transistors in the 1950s, which made digital electronic computers easier and faster to build, and then microchips. While CSIRAC had a long operational life, it did the same amount of processing in 14 years that a smartphone can do in about a minute.
Fitzsimmons is now chairman of the Pearcey Foundation, created in 1998 in memory of CSIRAC’s designer. He recalls meeting Pearcey in the 1960s, when Fitzsimmons was starting out in computer sales for Data General.
“He was an oddball guy but a completely original thinker,” Fitzsimmons said. “In 1946 he was already envisioning what he called an ‘automatic encyclopaedic service delivered via a national teleprinter or telephone system’. That’s basically electronic libraries and the Internet. I see Pearcey and the CSIRAC story as an inspiration of what Australians can do.”
A fresh chance
These days, another new chapter in computer technology is being written thanks to an explosion of investment by governments and venture capital in quantum computing.
Modelling by the CSIRO in 2022 predicted quantum computing will generate $2.2 billion in Australian revenue by 2030 and nearly $6 billion by 2045, creating 8,700 new jobs by 2030 and 19,400 by 2045.
While Australia may have missed an opportunity at the birth of the computer age with CSIRAC, the same cannot be said of quantum computing.
There’s globally renowned research coming from Australian universities, and notable local start-ups: like Q-CTRL, which makes devices and software to improve the performance of quantum hardware; Silicon Quantum Computing, focusing on single-atom qubits for information processing; and Diraq, which relies on spin qubits and existing microchip technology used by today’s classical computers.
“If these Australian companies make it, it’ll be fantastic,” Fitzsimmons said. “And we’re right there at the beginning — there’s strong backing and lots of money flowing in. It’s very positive.”
Thorne, a Fellow of the Australian Computer Society, agrees. “We’re giving it a much better shot this time. And government and industry have a more sophisticated view of the significance of high technology and its potential. But it’s still a hard road to hoe because this is an area that’s exceptionally competitive.”
Images of CSIRAC: Courtesy of Museums Victoria, and the CSIRO and University of Melbourne archives.