CSIRAC: Australia's first digital computerCSIRAC (an acronym for 'Commonwealth Scientific and Industrial Research Organisation Automatic Computer') was a valve-driven computer that ran its first test program in 1949, back when it was known as 'CSIR Mk1'. The main system comprised nine steel cabinets containing 2000 valves that weighed over 7000kg.
CSIRAC stored data using mercury acoustic delay lines; an early type of serial-access refreshable memory. It boasted a 1000Hz memory clock and a serial bus that transferred one bit at a time. After experiments with punch card inputs, the machine graduated to using paper tape.
Like all computers of the time, CSIRAC did not have an operating system. A programming language, called INTERPROGRAM, was eventually written for the system in 1960.
[Image credit: Museum of Victoria]