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.