Mainframe Computer
Mainframe computers are large computers designed to be central sources of digital computer operations and to provide data storage for large amounts of information. The name came from the room-sized first computers, such as the Mark I at Harvard University and ENIAC at the University of Pennsylvania. The main frame was the case that held it.
The first generation of commercial computers was entirely mainframe, beginning with UNIVAC (UNIVersal Automatic Computer), built in 1950 by J. Presper Eckert and John Mauchly and manufactured by Remington Rand. These computers had thousands of bulky vacuum tubes for processing, mercury delay lines or magnetic drums for memory, punched cards for input and output, miles of wiring, and large power requirements. They were used for individual data-processing problems. UNIVAC became famous when it accurately predicted the outcome of the 1952 presidential election. Other typewriter, pocket calculator, and control equipment companies quickly entered the computer market, including Burroughs, National Cash Register, and Honeywell.
Second generation computers, such as the IBM 1401, were also mainframes. They were developed in the late 1950s and featured much faster transistor processors, invented by scientists at Bell Laboratories, and magnetic core memories, invented by An Wang. They used high-level (English-like) programming languages developed during the 1950s, principally COBOL (COmmon Business-Oriented Language), developed by Grace Hopper and others in the United States Navy, and FORTRAN (FORmula TRANslation), developed by John Backus and others at IBM. These computers could process large amounts of data, but they generally did not allow immediate ("real time") interaction with their users.
The height of mainframes' popularity came with third generation computers of the mid-1960s, such as the IBM System/360. They used the much faster integrated circuits for processors and had operating systems for overall control. The S/360, for example, offered disk, tape, and card input and output, as well as a printer. Comparable mainframes were built by other companies in the United States, Japan, Germany, and elsewhere. These computers were designed for central data-processing facilities, with many terminals for users. They could run several applications programs at the same time. Mainframe systems, such as the IBM System/370 (successor to the S/360) cost one million dollars or more.
In the late 1970s, mainframes began to give way to small, but powerful computers--the fourth generation--that let users directly manage their own data. By the early 1990s, many companies were downsizing--moving from mainframes to less-expensive networks of these newer machines. Though a few companies still make them and many remain in use, the day of the mainframe has largely passed.
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