Summary

Cabinet holding the control circuitry for the auxiliary store of CSIRAC (formerly CSIR Mk 1). In Melbourne, the circuitry controlled a magnetic disk. Data was initially stored on one side of the disk. In 1962, in Melbourne, the capacity was increased to include the second side using a new set of read/write circuitry using transistors. The disk, installed in Melbourne, replaced the magnetic drum used in Sydney; however, the name 'drum' remained in use.

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, although the metal cabinets were first used in 1949, changes were made to the structure and circuitry over the period of CSIRAC's working life.

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