This book is a collection of refereed invited papers on the history of computing from the 1940s to the 1990s with one paper going back to look at Italian calculating/computing machines from the first century to the 20th century. The 22 papers cover a wide range of computing related topics such as specific early computer systems, their construction, their use and their users; software programming and operating systems; people involved in the theory, design and use of these computers; computer education; and conservation of computing technology. Many of the authors were actually involved in the events they describe and share their specific reflections on the history of computing.