Within a few years of its invention in 1959, the integrated circuit (microchip)--tiny, complex electronic circuits on a single chip of silicon--had become reliable and inexpensive. The president of Texas Instruments, Patrick Haggerty, wanted to demonstrate the potentially pervasive uses of the integrated circuit, which was mostly confined to military and industrial functions. In October 1965, Haggerty challenged Jack Kilby, a TI engineer and coinventor of the microchip, to design a miniature calculator that would be as powerful as desk models but small enough to fit into a coat pocket. Kilby was a man who thrived on solving difficult technical problems. He assembled a three-man team of himself and two fellow TI engineers that produced a prototype within a year. Jerry Merryman, a self-taught electrical engineer, designed the logic circuits to fit within the power and space limitations. James Van Tassel, an expert on semiconductor components, developed...