When were transistors first invented?
Consumer electronics
For its first fifty years the phonograph turntable did not use electronics; the needle and soundhorn were purely mechanical technologies. However, in the 1920s radio broadcasting became the basis of mass production of radio receivers. The vacuum tubes that had made radios practical were used with record players as well, to amplify the sound so that it could be played through a loudspeaker. Television was soon invented, but remained insignificant in the consumer market until the 1950s. The transistor, invented in 1947 by Bell Laboratories, led to significant research in the field of solid-state semiconductors in the early 1950s. The transistor's advantages revolutionized that industry along with other electronics. By 1959 Fairchild Semiconductor had introduced the first planar transistor from which come the origins of Moore's law. Integrated circuits followed when manufacturers built circuits (usually for military purposes) on a single substrate using electrical connections between circuits within the chip itself. Bell's invention of the transistor and the development of semiconductors led to far better and cheaper consumer electronics, such as transistor radios, televisions, and by the 1980s, affordable video game consoles and personal computers that regular middle-class families could buy.
United States
The invention of the transistor in the 1950s, a key active component in practically all modern electronics, led to many technological developments and a significant expansion of the U.S. technology industry. This, in turn, led to the establishment of many new technology companies and regions around the country such as Silicon Valley in California. Advancements by American microprocessor companies such as Advanced Micro Devices (AMD), and Intel along with both computer software and hardware companies that include Adobe Systems, Apple Inc., IBM, Microsoft, and Sun Microsystems created and popularized the personal computer. The ARPANET was developed in the 1960s to meet Defense Department requirements, and became the first of a series of networks which evolved into the Internet.