in 1957 From 1952 into the late 1960s, IBM manufactured and marketed several large computer models, known as the
IBM 700/7000 series. The
first-generation 700s were based on
vacuum tubes, while the later, second-generation 7000s used
transistors. These machines established IBM's dominance in
electronic data processing ("EDP"). IBM had two model categories: one (701, 704, 709, 7030, 7090, 7094, 7040, 7044) for engineering and scientific use, and one (702, 705, 705-II, 705-III, 7080, 7070, 7072, 7074, 7010) for commercial or data processing use. The two categories, scientific and commercial, generally used common peripherals but had completely different
instruction sets, and there were incompatibilities even within each category. IBM initially sold its computers without any software, expecting customers to write their own; programs were manually initiated, one at a time. Later, IBM provided
compilers for the newly developed higher-level
programming languages
Fortran,
COMTRAN and later
COBOL. The first
operating systems for IBM computers were written by IBM customers who did not wish to have their very expensive machines (US$2M in the mid-1950s) sitting idle while operators set up jobs manually. These first operating systems were essentially scheduled work queues. It is generally thought the first operating system used for real work was
GM-NAA I/O, produced by
General Motors' Research division in 1956. IBM enhanced one of GM-NAA I/O's successors, the
SHARE Operating System, and provided it to customers under the name
IBSYS. As software became more complex and important, the cost of supporting it on so many different designs became burdensome, and this was one of the factors which led IBM to develop
System/360 and its operating systems. The
second generation (transistor-based) products were a mainstay of IBM's business and IBM continued to make them for several years after the introduction of the System/360. (Some
IBM 7094s remained in service into the 1980s.) ==Smaller machines==