CSIRAC computer. 768 words storage in mercury delay lines, 20 bit words. Comprises racks, printers, storage delay lines, paper tape readers and punches.

CSIRAC (previously CSIR Mark 1) computer was designed by Trevor Pearcey and Maston Beard at the Division of Radiophysics in 1947. Construction was commenced in 1948 and the first program was run in 1949. In 1956 it was moved to the University of Melbourne Computation Laboratory.

CSIRAC at Melbourne consisted of two rows of cabinets, a control console, input and output devices, test equipment and an off-line paper tape editing area. There were nine cabinets, five in the front row and four in the back. Cool air was blown up through all the cabinets from the basement below. The auxiliary memory (disk drive) occupied the space that would have been occupied by a cabinet in the back row.

The five front row cabinets contained (from left to right viewed from the front) power supplies, input and output circuitry, clock and control circuits, arithmetical circuits and memory control circuits. The four back row cabinets contained (from left to right viewed from the front) power supplies, auxiliary store control circuits, 'disk drive', auxiliary test power supplies and memory control circuits.

The date range (1949-1964) is given to indicate that changes were made to the structure and circuitry over the period of CSIRAC's working life. CSIRAC is on the Victorian Heritage Register, Number H2217.


CSIRAC was the fourth stored program computer in the world and the first one in Australia. It is the only intact first generation computer left on the planet.

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