One of the lesser accounts of the computer revolution--unfocused and often uncertain. Science writer Ritchie (The Ring of Fire, Spacewar) first discourses superficially on Darwinian evolution and the human brain--using the infelicitous term ""Lamarckian"" evolution to describe computer progress, where cultural evolution would have been less controversial and more appropriate. The brief background sketches of both well-known pioneers (Pascal, Leibnitz, Babbage, von Neumann, Wiener, Turing), and certain of the lesser-known, disclose some common misconceptions, as well as the author's biases (especially re Pascal and Babbage)--though there are occasional unfamiliar or telling anecdotes. What's left is some deft scene-setting--at Yale, MIT, Harvard, Berkeley, SRI International--and fast limning of interviewees; some juicy bits on robotics, artificial intelligence, and the pace of progress--as seen by ""strong"" or ""weak"" Al believers, Strong believers are defined as individuals who believe that: 1) Mind is a Program; 2) Brains are merely ""Mind Builders""; 3) If it passes Turing's Test, it's intelligent. (I.e., if a computer convinces you in remote conversation that its behavior is intelligent, it really is intelligent.) Those who hold weak views find programming machines enlightening for what they teach about human thought processes, but remain convinced that computers will never reach replicating, creative, humorous, or emotional stages. Though most of the programs illustrated are familiar, some new attempts at language translation are exceptions. A chapter on silicon-chip design is also a plus. Otherwise the diffuse focus, combined with a tendency to agree with everyone (yet plump for the creation of a supermind), makes for a jumble. G.L. Simons' Are Computers Alive? (p. 704) and Neil Frude's The Intimate Machine (p. 804), though both the work of enthusiasts, are each in its way steadier-on and more interesting; for the larger picture, Margaret Boden's Artificial Intelligence and Natural Man is still unsurpassed.