CSIR Mk1 & CSIRAC, Trevor Pearcey & Geoff Hill, Australia, 1951

Trevor Pearcey at the CSIR Mk1

Trevor Pearcey at the CSIR Mk1

CSIRAC was an early digital computer designed by the British engineer Trevor Pearcey as part of a research project at CSIRO ( Sydney-based Radiophysics Laboratory of the Council for Scientific and Industrial Research)  in the early 1950′s. CSIRAC was intended as a prototype for a much larger machine use and therefore included a number of innovative ‘experimental’ features such as video and audio feedback designed to allow the operator to test and monitor the machine while it was running. As well as several optical screens,  CSIR Mk1 had a built-in Rola 5C  speaker mounted on the console frame. The speaker was an output device used to alert the programmer that a particular event had been reached in the program; commonly used for warnings, often to signify the end of the program and sometimes as a debugging aid. The output to the speaker was basic raw data from the computer’s bus and consisted of an audible click. To create a more musical tone, multiple clicks were combined using a short loop of instructions; the timing of the loop giving a change in frequency and therefore an audible change in pitch.

A closeup of the CSIRAC console switch panel. Note the multiple rows of 20 switches used to set bits in various registers.

The CSIRAC console switch panel with multiple rows of 20 switches used to set bits in various registers.

The first piece of digital computer music was created by Geoff Hill and Trevor Pearcey on the  CSIR Mk1 in 1951 as a way of testing the machine rather than a musical exercise. The music consisted of excerpt from  popular songs of the day; ‘Colonel Bogey’, ‘Bonnie Banks’, ‘Girl with Flaxen Hair’ and so on. The work was perceived as a fairly insignificant technical test and wasn’t recorded or widely reported:

An audio reconstruction  of CSIRAC playing Colonel Bogey (c.1951)
 CSIRAC plays In Cellar Cool with a simulation of CSIRAC’s room noises.

CSIRAC – the University’s giant electronic brain – has LEARNED TO SING!

…it hums, in bathroom style, the lively ditty, Lucy Long. CSIRAC’s song is the result of several days’ mathematical and musical gymnastics by Professor T. M. Cherry. In his spare time Professor Cherry conceived a complicated punched-paper programme for the computer, enabling it to hum sweet melodies through its speaker… A bigger computer, Professor Cherry says, could be programmed in sound-pulse patterns to speak with a human voice…
The Melbourne Age, Wednesday 27th July 1960

Later version of the CSIRAC at The University of Melbourne

Later version of the CSIRAC at The University of Melbourne

…When CSIRAC began sporting its musical gifts, we jumped on his first intellectual flaw. When he played “Gaudeamus Igitur,” the university anthem, it sounded like a refrigerator defrosting in tune. But then, as Professor Cherry said yesterday, “This machine plays better music than a Wurlitzer can calculate a mathematical problem”…
Melbourne Herald, Friday 15th June 1956:

Portable computer: CSIRAC on the move to Melbourne, June 1955

Portable computer: CSIRAC on the move to Melbourne, June 1955

The CSIR Mk1 was dismantled in 1955 and moved to The University of Melbourne, where it was renamed CSIRAC. Professor of Mathematics, Thomas Cherry, had a great interest in programming and music and he created music with CSIRAC. During it’s time in Melbourne the practice of music programming on the CSIRAC was refined allowing the input of music notation. The program tapes for a couple of test scales still exist, along with the popular melodies ‘So early in the Morning’ and ‘In Cellar Cool’.

Music instructions for the CSIRAC by Thomas Cherry

Music instructions for the CSIRAC by Thomas Cherry

Music instructions for the CSIRAC by Thomas Cherry

Music instructions for the CSIRAC by Thomas Cherry




Later version of the CSIRAC at The University of Melbourne

Later version of the CSIRAC at The University of Melbourne


Sources

http://www.audionautas.com/2011/09/music-of-csirac.html

Australia’s First Computer Music, Common Ground Publishing, Paul Doornbusch pauld@koncon.nl

http://ww2.csse.unimelb.edu.au/dept/about/csirac/music/index.html