The convenient dry-copying process for printed pages is among the truly revolutionary inventions of the century. In 1937 Chester Carlson, a New York patent attorney, developed the concept of applying an electrostatic charge on a plate coated with a photoconductive material. On November 22, 1938, Carlson dusted powder dyed with evergreen spores across an exposed plate and transferred the imprint to the surface of a paper.
Communications and Data Processing
Edison's simple and unprecedented instrument allowed for the first time the permanent recording and reproduction of sound, especially the human voice. On December 6, 1877, Edison put tinfoil around the cylinder, turned the handle of the shaft and, shouting into one of the diaphragms, recorded a verse of Mary Had a Little Lamb "almost perfectly." From this machine evolved the phonographs and record industries of the world.
The IBM 350 disk drive storage development led to the breakthrough of on-line computer systems by providing the first storage device with random access to large volumes of data. Since its introduction on September 4, 1956, it has become the primary computer bulk-storage medium, displacing punched cards and magnetic tapes and making possible the use of the computer in such areas as airline reservations, automated banking, medical diagnosis, and space flights.
The ABACUS II, designed and built by Texas Instruments, was the first practical automated production machine for the assembly of integrated circuits. Using heat and pressure, it bonded fine gold wire to microscopic contacts on the silicon chip and pin connections on the package.
The ABACUS II could maintain a positioning accuracy of ± 0.00025 inch while bonding up to 375 devices an hour. Following the success of this prototype, almost 1,000 ABACUS II wire bonders were built, making the economical mass production of integrated circuits a reality.