Definitions for mainframeˈmeɪnˌfreɪm
Random House Webster's College Dictionary
a large computer, often the hub of a system serving many users.
Origin of mainframe:
mainframe, mainframe computer(noun)
a large digital computer serving 100-400 users and occupying a special air-conditioned room
central processing unit, CPU, C.P.U., central processor, processor, mainframe(noun)
(computer science) the part of a computer (a microprocessor chip) that does most of the data processing
"the CPU and the memory form the central part of a computer to which the peripherals are attached"
A large, powerful computer able to manage very many simultaneous tasks and communicate with very many connected terminals; used by large, complex organizations (such as banks and supermarkets) where continuously sustained operation is vital
The New Hacker's Dictionary
Term originally referring to the cabinet containing the central processor unit or ‘main frame’ of a room-filling Stone Age batch machine. After the emergence of smaller minicomputer designs in the early 1970s, the traditional big iron machines were described as ‘mainframe computers’ and eventually just as mainframes. The term carries the connotation of a machine designed for batch rather than interactive use, though possibly with an interactive timesharing operating system retrofitted onto it; it is especially used of machines built by IBM, Unisys, and the other great dinosaurs surviving from computing's Stone Age.It has been common wisdom among hackers since the late 1980s that the mainframe architectural tradition is essentially dead (outside of the tiny market for number-crunching supercomputers having been swamped by the recent huge advances in IC technology and low-cost personal computing. The wave of failures, takeovers, and mergers among traditional mainframe makers in the early 1990s bore this out. The biggest mainframer of all, IBM, was compelled to re-invent itself as a huge systems-consulting house. (See dinosaurs mating and killer micro).However, in yet another instance of the cycle of reincarnation, the port of Linux to the IBM S/390 architecture in 1999 — assisted by IBM — produced a resurgence of interest in mainframe computing as a way of providing huge quantities of easily maintainable, reliable virtual Linux servers, saving IBM's mainframe division from almost certain extinction.