mainframe

n.	1.	(Computers) A large digital computer serving 100-400 users and occupying a special air-conditioned room. At any given point in development of computer technology, the mainframe will be faster, have large main memeory, and be more capable than a minicomputer, which will in turn be faster and more capable than a personal computer. The typical personal computer in 1999 is faster than a mainframe was in 1970.
	2.	The board holding the CPU and the memory forming the central part of a computer to which the peripherals are attached.

Noun	1.	mainframe - a large digital computer serving 100-400 users and occupying a special air-conditioned room Synonyms: mainframe computer
	2.	mainframe - (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 Synonyms: C.P.U., central processing unit, central processor, CPU, processor

(computer)

mainframe - A 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 time-sharing 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 (see Cray)), having been swamped by the recent huge advances in integrated circuit technology and low-cost personal computing. As of 1993, corporate America is just beginning to figure this out - the wave of failures, takeovers, and mergers among traditional mainframe makers have certainly provided sufficient omens (see dinosaurs mating). Supporters claim that mainframes still house 90% of the data major businesses rely on for mission-critical applications, attributing this to their superior performance, reliability, scalability, and security compared to microprocessors.

digital computer, mainframe computer, supercomputer