In 1999, as I was finishing work on my book Code: The Hidden Language of Computer Hardware and Software , I had ideas for four "spin-off" books. I prepared single-page descriptions of each of these book ideas and showed them to my agent. None of these books was "normal" in any way. One of the oddest was a book I called Mr. Turing's Computing Machine . In researching Code , I read (or tried to read) many of the seminal books and papers that contributed to the early history of computing. One of these was Alan Turing's 1936 paper "On Computable Numbers, with an Application to the Entscheidungsproblem" in which he invents the imaginary computer now called the Turing Machine. In trying to comprehend this paper, I thought "This is such an important paper in the history of computing that somebody should really write a book explaining what's going on in here." I think the whole concept of the book sprung into my head almost fully formed: I would take Turing's paper and annotate the living daylights Read More...