This paper examines the development of a number of computers designed and built in Australia that really changed everything! Australia designed and built CSIRAC, the fourth stored program computer in the world. Prior to this however, in 1913 the Automatic Totalisator, although not a computer, performed many of the calculations later done by computers. SILLIAC, based on the ILLIAC was built in Australia. UTCOM and WREDAC, although built in the UK, were extensively modified in Australia. In the early microcomputer era the Australian designed and built Microbee computer was used extensively in homes and schools. The paper then discusses the ill-fated project to design and built an Australian Educational Computer. These computers were each designed and built for a purpose and the paper looks at the people, technologies and events that propelled this process. Actor-network theory is used as a lens for understanding the human and non-human elements of these historical developments.