Changes

==360==

==360==

The mainframe computer entered American life in a major way in 1965 when IBM introduced its Model 360. This multimillion-dollar machine was quickly adopted by large businesses, government agencies and universities. Although it used transistors instead of vacuum tubes, the mainframe ran hot and required special facilities and 24-hour air conditioning, and was always attended by white-coated technicians. IBM dominated the worldwide computer market, as rivals (the "seven dwarfs") could match IBM's technology, but not its reputation. Technological advances every year brought bigger and faster mainframes and hastened the restructuring of most bureaucratic enterprises around the mainframe. The mainframe centralized computing power high up in an organization, where legions of FORTRAN and COBOL programmers wrote codes that harnessed raw computing power to specialized tasks. Bureaucracies expanded, assigning lower echelons the task of preparing forms for keypunching holes on cards that fed the machine. Most jobs were simple and routine, usually just the rapidly rapid processing of large numbers of highly stylized forms such as monthly electric bills. By the 1970s, distributed processing allowed clerks to use terminals connected directly to the mainframe. These were "dumb" terminals without their own computing power. Upstart companies introduced smaller, much cheaper "minicomputers" in the 1970s that handled most medium and small jobs as well as a mainframe. By the early 1990s, the mass introduction of PCs ("personal computers", originally called "microcomputers") radically undercut the market for mainframes and minis both.  

The mainframe computer entered American life in a major way in 1965 when IBM introduced its Model 360. This multimillion-dollar machine was quickly adopted by large businesses, government agencies and universities. Although it used transistors instead of vacuum tubes, the mainframe ran hot and required special facilities and 24-hour air conditioning, and was always attended by white-coated technicians. IBM dominated the worldwide computer market, as rivals (the "[[seven dwarfs]]") could match IBM's technology, but not its reputation. Technological advances every year brought bigger and faster mainframes and hastened the restructuring of most bureaucratic enterprises around the mainframe. The mainframe centralized computing power high up in an organization, where legions of FORTRAN and COBOL programmers wrote codes that harnessed raw computing power to specialized tasks. Bureaucracies expanded, assigning lower echelons the task of preparing forms for keypunching holes on cards that fed the machine. Most jobs were simple and routine, usually just the rapidly rapid processing of large numbers of highly stylized forms such as monthly electric bills. By the 1970s, distributed processing allowed clerks to use terminals connected directly to the mainframe. These were "dumb" terminals without their own computing power. Upstart companies introduced smaller, much cheaper "minicomputers" in the 1970s that handled most medium and small jobs as well as a mainframe. By the early 1990s, the mass introduction of PCs ("personal computers", originally called "microcomputers") radically undercut the market for mainframes and minis both.

==PCs==

==PCs==