Constructed by the School of Physics, the SILLIAC and its power supply filled up two rooms. It performed its first successful scientific calculation on July 4, 1956, but was not officially declared "open" until September 12 that year
http://www.smh.com.au/news/technology/the-computer-that-launched-our-it-revolution/2006/09/11/1157826868138.html?from=rss