_Bootstrapping: Douglas Engelbart, Coevolution, and the Origins of Personal Computing_ by Thierry Bardini

https://www.amazon.com/exec/obidos/ASIN/0804738718/ref=nosim...

I've read (most of) this one. It is extremely well-researched but often a little too dry and academic for my taste. _Dormouse_ is more accessible, but both are great for Engelbart nerds.