The MANIAC III (''Mathematical Analyzer Numerical Integrator and Automatic Computer Model III'') was a second-generation electronic computer (i.e., using

solid-state electronics Solid-state electronics means semiconductor electronics: electronic equipment using semiconductor devices such as transistors, diodes and integrated circuits (ICs). The term is also used as an adjective for devices in which semiconductor electr ...

rather than

vacuum tube A vacuum tube, electron tube, valve (British usage), or tube (North America), is a device that controls electric current flow in a high vacuum between electrodes to which an electric voltage, potential difference has been applied. The type kn ...

s), built in 1961 for use at the

Institute for Computer Research An institute is an organisational body created for a certain purpose. They are often research organisations (research institutes) created to do research on specific topics, or can also be a professional body. In some countries, institutes can ...

at the

University of Chicago The University of Chicago (UChicago, Chicago, U of C, or UChi) is a private research university in Chicago, Illinois. Its main campus is located in Chicago's Hyde Park neighborhood. The University of Chicago is consistently ranked among the b ...

. It was designed by

Nicholas Metropolis Nicholas Constantine Metropolis (Greek: ; June 11, 1915 – October 17, 1999) was a Greek-American physicist. Metropolis received his BSc (1937) and PhD in physics (1941, with Robert Mulliken) at the University of Chicago. Shortly afterwards, ...

and constructed by the staff of the Institute for Computer Research. Its design was changed to eliminate vacuum tubes, thus it occupied a very small part of a very large and powerfully air-conditioned room. It used 20,000 diodes, 12,000 transistors, and had 16K 48-bit words of

magnetic-core memory Magnetic-core memory was the predominant form of random access, random-access computer memory for 20 years between about 1955 and 1975. Such memory is often just called core memory, or, informally, core. Core memory uses toroids (rings) of a ...

. Its

floating-point In computing, floating-point arithmetic (FP) is arithmetic that represents real numbers approximately, using an integer with a fixed precision, called the significand, scaled by an integer exponent of a fixed base. For example, 12.345 can b ...

multiplication time was 71 microseconds, and division time was 81 microseconds. The MANIAC III's most novel feature was unnormalized

significance arithmetic Significance arithmetic is a set of rules (sometimes called significant figure rules) for approximating the propagation of uncertainty in scientific or statistical calculations. These rules can be used to find the appropriate number of significant ...

floating point. This allowed users to determine the change in precision of results due to the nature of the computation. It weighed about {{convert, 600, lb, kg.

References

1961 BRL report
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