mainframe

mainframe n.  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 {dinosaur}s 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.  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}).