I recommend the following. Don't know why, but after I read a biography on Oppenheimer I just had to read this too.<p>Aspray, William (1990) John von Neumann and the origins of modern computing. MIT Press.
(<a href="http://www.amazon.com/Neumann-Origins-Modern-Computing-History/dp/0262011212/" rel="nofollow">http://www.amazon.com/Neumann-Origins-Modern-Computing-Histo...</a>)