= M =
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 (see
cray)), 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 quanitities of easily maintainable,
reliable virtual Linux servers, saving IBM's mainframe division
from almost certain extinction.
--The Jargon File version 4.3.1, ed. ESR, autonoded by rescdsk.