The+Four+Generations+of+Computers

__**The Four Generations of Computer Components**__ by //Jeff// //Luchetti//

Early modern computers can be grouped into 4 generations marked by differences and improvements in technology. Each impovement in technology has resulted in computers of faster speed and lower cost. All of the contributions to computer technology should not be divided only into these categories, because their were many technological advances in between.

__The First Generation(1945-1959)__: __Vacuum Tubes__

Lee De Forest(1873-1961), an electrical engineer, invented the vacuum tube in 1906. It was the fundamental technology used to construct most electronic devices such as radios, televisions, radar, etc. It is the primary technology used for first generation computers. The operational general purpose computer was known as ENIAC (Electronic Numerical Integrator and Computer), and was built in 1943. It used 18,000 vacuum tubes. It was used mainly for war-related computations such as construction of the atomic bomb, during the World War 2 era. It used punch cards for input and output and was programmed by plug board wiring. The whole computer was 100 feet long and had 20 ten-digit rosters for temporary calculations. Most of the computers in the First Generation were much like the ENIAC.

__The Second Generation of Computers(1959-1964)__: __Transistors__ The Second Generation of Computers was based not on vacuum tubes, but on transistors. John Bardeen (1908–1991), William B. Shockley (1910–1989), and Walter H. Brattain (1902–1987) invented the transistor in the mid-1949s. Second generation machines were programmed in languages such as COBOL (Common Business Oriented Language) and FORTRAN (Formula Translator) and were generally used for business and scientific tasks. Magnetic disks and tape were used for data storage. The UNIVAC created the first boom for commercial use of computers.

__The Third Generation of Computers(1965-1970)__: __Integrated Circuit__ The third generation of computers introduced the use of the integrated circuit. Circuits were developed on single chips of silicon instead of large circuit boards. The most important advancement in technology during this period was the new minicomputer, which allowed smaller businesses to use computers. The minicomputer was equivalent to a large computer, but it had smaller memory and slower processing. Another computer made in this time period was IBM's 360 series mainframe computer.

__The Fourth Generation of Computers (1971-present)__: __Microprocessors__ Microprocessors have been made during this time period. They were derived from integrated circuits, allowing them to be placed on the office desk. Microprocessor technology is now found in all modern computers. The chips themselves can be made inexpensively and in large quantities. Another new invention of the fourth generation is the personal computer. The computers of the fourth generation are roughly 100 times smaller than those of generation one, yet they are at least as powerful, if not more so. New inventions are constantly being made, such as the laptop and constant updates to windows and other programs. Many more are still to come. __Sources:__
 * 1) http://www.cknow.com/tutorcom/hist06_gen.htm
 * 2) http://www.bookrags.com/research/generations-computers-csci-01/