In the late 1950s and early 1960s, mega corporations of the day began to handle data that rivaled government requirements. This data could not be handled manually, let alone cost-effectively. Accounting and financial information, due to its repetitive nature and heavy volume, became a prime candidate for automation. Initial accounting programs were written for mainframe computers, not surprisingly, since IBM and its Big Irons ruled the computer world. Early mainframe computers were large, due to the ferrite core memory, and cumbersome. The processing intelligence was centralized in the mainframe. Mainframes served a large number of users, and data was processed in a batch mode. Users submitted data using dumb terminals and jobs were processed based on the length of the queue and priority of the jobs. Mainframes provided a high level of security and reliability. Minicomputers, pioneered by the Digital Equipment Corporation, had similar capabilities but were smaller and less powerful. Currently, distinctions between mainframes and minis are very blurred, and for our purposes make very little practical difference.