B005HFI0X2 EBOK Read Online Free PDF

the world. Finally in April 1964, IBM unveiled its System/360 product line of software-compatible mainframe computers. The System/360 was described as “the computer that IBM made, that made IBM.”
    FROM VACUUM TUBE TO SILICON CHIP
    Early computers were hobbled by reliance on vacuum tubes that took up space and generated heat. At AT&T’s Bell Laboratories, the physicist William Shockley led a research group that developed solid-state transistors between 1947 and 1950. By the mid-1950s, Texas Instruments led in the manufacture of silicon transistors. The next step, propelled by US military demands for smaller computers, was the combination of transistors on a single circuit board. Working independently of each other, Robert Noyce at Fairchild Semiconductor and Gordon Moore at Intel invented the silicon “chip,” a single “integrated circuit” that combined transistors and capacitors. Moore’s law, named after Gordon Moore, was based on the fact that the number of transistors per microchip doubled roughly every seventeen months after 1972, when the Intel 8008 chip had 2,500 transistors, to 2000, when the Pentium 4 processor had forty-two million transistors.
    Soon there were three kinds of integrated circuits: memory chips, microprocessors, developed by Intel, and microcapacitors. Raytheon and the optical equipment manufacturer Perkin-Elmer developed a method of photolithography fabrication that made possible the mass production of silicon chips.
    SIDE TRAIL: RAYTHEON AND THE RADARANGE
    Let us follow a side trail on the imaginary memex to learn more about Raytheon. It brings us to the microwave oven, the first major innovation in cooking since primitive hominids began to cook with fire.
    Percy Spencer, an engineer working at Raytheon, was startled one day in 1946 when a candy bar in his pocket melted as he was working on a new vacuum tube called a magnetron. Realizing that the magnetron was the cause, Spencer successfully popped popcorn kernels by placing them nearby and then cooked an egg, which exploded in his face. By spring 1946, Spencer and a colleague, P. R. “Roly” Hanson, were working on a project given the secret code name Speedy Weenie. Their work led to Raytheon’s 1946 patent for the microwave oven. In 1947, a contest among employees to name the device produced a winner: “Radarange.” By 1976, more American households owned a microwave oven than owned a dishwasher. 28
    At the time that it invented the microwave, Raytheon was a leading manufacturer of vacuum tubes, having acquired or merged with other companies in the field including Acme-Delta and Q.R.S. Company. In 1928, it had chosen the name Raytheon Manufacturing Company to replace its previous name, the American Appliance Company, because of the visibility of one of its products called the Raytheon (“light of the gods”), an electron tube used in a “battery eliminator” that converted the alternating current in household wiring to direct current that could be used in radios, as an alternative to batteries.
    The Raytheon electron tube was the invention of Charles G. Smith, who had founded the American Appliance Company in Cambridge, Massachusetts, in 1922, with two partners. One was an engineer named Laurence K. Marshall. The other founder of the company to be known as Raytheon was Marshall’s engineering school classmate and college roommate at Tufts University, the thirty-two-year-old Vannevar Bush.
    THE ORIGINS OF SILICON VALLEY
    Using a skip trail on the memex, we return to the main trail and Bush. Was there any connection between Bush and Silicon Valley? Under the label “Silicon Valley” we find an interesting side trail.
    We learn that Professor Bush’s first graduate student at MIT was named Frederick Terman. After taking a job as a professor of electrical engineering at Stanford University, Terman was disappointed by the lack of employment opportunities for graduates of his department in Northern California. With his