---
id: csirac
title: "CSIRAC"
year: 1951
category: "AI & Code"
lang: en
canonical: https://nodemusic.cc/node/csirac
source: node.music
---

# CSIRAC (1951)

AI & Code · https://nodemusic.cc/node/csirac

## Summary

Australia's first computer played marches and Scottish songs, yet none of this music was ever recorded: management dismissed it as a parlour trick. For half a century, all that survived was the program on punched paper tape.

## Full text

By the late 1940s, physics calculations had grown so vast and tedious that scientists needed a machine that could compute on its own, without a human at every step. The Sydney Radiophysics Laboratory of CSIR, Australia's Council for Scientific and Industrial Research, had spent the war building radar and knew vacuum tubes and pulses better than anyone in the country.

Out of that radar technology, Trevor Pearcey and Maston Beard began building an automatic computer in 1947. The CSIR Mk1 became Australia's first computer and one of the first in the world to hold its program in its own memory: more than 2,000 valves, seven tonnes, 30 kilowatts, and a memory of mercury tubes in which data circulated as pulses. It ran its first program, multiplying two numbers, in November 1949. "We all shouted 'Hooray!' and went back to work," Pearcey recalled.

The machine had no screen, so a loudspeaker, the hooter, was fitted to the console to call the operator or mark the end of a program. Why it was made programmable is recorded nowhere: Pearcey seems to have seen a hooter on the Manchester computer and copied it without much thought.

The possibility was heard by the machine's first programmer, mathematician Geoff Hill. He came from a musical family: his mother and sister taught music all their lives, and he, like his mother, had perfect pitch. Hill realised that pulses sent to the speaker at regular intervals would make a note instead of clicks. Late one evening he rang his mother, held the receiver to the speaker and asked whether the scale was in tune. She thought he was fooling about with tissue paper and a comb, and told him to come home: his dinner was in the oven.

The scale did not come easily. Data in the mercury tubes ran in circles, and each number could be fetched only as it passed the exit. Hill laid the numbers out in memory so that the pulses reached the speaker at even intervals, in effect writing a timetable for the memory. First on the tape after the scale came the Colonel Bogey March.

The CSIR Mk1 was built as a prototype for a more powerful machine that would be sold. The commercial project fell through, and the computer's future hung by a thread. The team decided to win it attention with music. In 1951 the CSIR Mk1 played for guests at Australia's first conference on computing machines. Pearcey wanted the tunes on the radio, and "Bonnie Banks", by one account, was programmed to impress Prime Minister Robert Menzies, a man of Scottish descent.

Management dismissed it all as a stunt. CSIR never officially acknowledged the music, it never reached the papers, and no one was allowed to record or broadcast it. That is why the oldest surviving recording of computer music is British: in November 1951 the BBC recorded a computer in Manchester that had begun to play a few months later.

In 1955 the machine moved to the University of Melbourne and was renamed CSIRAC. No composers were ever invited, though the most obvious candidate walked right past the windows. In the late 1950s the lab staff more than once watched Percy Grainger go by, a composer who built his own "free music" machines. Nobody thought to show him the computer.

Of the music meant to save the machine, only the program survived. Half a century later, working from a 1953 punched paper tape, composer and researcher Paul Doornbusch and former CSIRAC engineers rebuilt the sound pulse by pulse. When he explained the machine's memory to Max Mathews of Bell Labs, Mathews groaned, imagining what it took to get a steady note out of it.

## People

- Paul Doornbusch (b. 1959) — Australian composer and computer music researcher.
- Max Mathews (1926–2011) — American engineer at Bell Labs.
- Geoff Hill (1928–1982) — Australian mathematician, the country's first programmer.

Wikipedia: https://en.wikipedia.org/wiki/CSIRAC