The MANIAC II (''Mathematical Analyzer Numerical Integrator and Automatic Computer Model II'') was a first-generation electronic

computer A computer is a machine that can be programmed to Execution (computing), carry out sequences of arithmetic or logical operations (computation) automatically. Modern digital electronic computers can perform generic sets of operations known as C ...

, built in 1957 for use at

Los Alamos Scientific Laboratory Los Alamos National Laboratory (often shortened as Los Alamos and LANL) is one of the sixteen research and development laboratories of the United States Department of Energy (DOE), located a short distance northwest of Santa Fe, New Mexico, in ...

. MANIAC II was built by the

University of California The University of California (UC) is a public land-grant research university system in the U.S. state of California. The system is composed of the campuses at Berkeley, Davis, Irvine, Los Angeles, Merced, Riverside, San Diego, San Francisco, ...

and the Los Alamos Scientific Laboratory, completed in 1957 as a successor to

MANIAC I __NOTOC__ The MANIAC I (''Mathematical Analyzer Numerical Integrator and Automatic Computer Model I'') was an early computer built under the direction of Nicholas Metropolis at the Los Alamos Scientific Laboratory. It was based on the von Neuma ...

. It used 2,850

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 and 1,040

semiconductor A semiconductor is a material which has an electrical resistivity and conductivity, electrical conductivity value falling between that of a electrical conductor, conductor, such as copper, and an insulator (electricity), insulator, such as glas ...

diode A diode is a two-terminal electronic component that conducts current primarily in one direction (asymmetric conductance); it has low (ideally zero) resistance in one direction, and high (ideally infinite) resistance in the other. A diode ...

s in the arithmetic unit. Overall it used 5,190 vacuum tubes, 3,050 semiconductor diodes, and 1,160

transistor upright=1.4, gate (G), body (B), source (S) and drain (D) terminals. The gate is separated from the body by an insulating layer (pink). A transistor is a semiconductor device used to Electronic amplifier, amplify or electronic switch, switch e ...

s. It had 4,096

word A word is a basic element of language that carries an semantics, objective or pragmatics, practical semantics, meaning, can be used on its own, and is uninterruptible. Despite the fact that language speakers often have an intuitive grasp of w ...

s of

memory Memory is the faculty of the mind by which data or information is encoded, stored, and retrieved when needed. It is the retention of information over time for the purpose of influencing future action. If past events could not be remembered, ...

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 ...

(with 2.4 microsecond access time), supplemented by 12,288 words of memory using

Williams tube The Williams tube, or the Williams–Kilburn tube named after inventors Freddie Williams and Tom Kilburn, is an early form of computer memory. It was the first random-access digital storage device, and was used successfully in several early co ...

s (with 15 microsecond access time). The word size was 48

bit The bit is the most basic unit of information in computing and digital communications. The name is a portmanteau of binary digit. The bit represents a logical state with one of two possible values. These values are most commonly represente ...

s. Its average multiplication time was 180

microseconds A microsecond is a unit of time in the International System of Units (SI) equal to one millionth (0.000001 or 10−6 or ) of a second. Its symbol is μs, sometimes simplified to us when Unicode is not available. A microsecond is equal to 1000 n ...

and the average division time was 300 microseconds. By the time of its decommissioning, the computer was all

solid-state Solid state, or solid matter, is one of the four fundamental states of matter. Solid state may also refer to: Electronics * Solid-state electronics, circuits built of solid materials * Solid state ionics, study of ionic conductors and their use ...

, using a combination of RTL, DTL and

TTL TTL may refer to: Photography * Through-the-lens metering, a camera feature * Zenit TTL, an SLR film camera named for its TTL metering capability Technology * Time to live, a computer data lifespan-limiting mechanism * Transistor–transistor lo ...

. It had an array multiplier, 15 index registers, 16K of 6-microsecond cycle time core memory, and 64K of 2-microsecond cycle time core memory. A NOP instruction took about 2.5 microseconds. A multiplication took 8 microseconds and a division 25 microseconds. It had a paging unit using 1K word pages with an associative 16-deep lookup memory. A 1-megaword CDC drum was hooked up as a paging device. It also had several ADDS Special-Order Direct-View Storage-Tube terminals. These terminals used an extended character set which covered about all the mathematical symbols, and allowed for half-line spacing for math formulas. For I/O, it had two

IBM 360 The IBM System/360 (S/360) is a family of mainframe computer systems that was announced by IBM on April 7, 1964, and delivered between 1965 and 1978. It was the first family of computers designed to cover both commercial and scientific applica ...

series nine-track and two seven-track 1/2" tape drives. It had an eight-bit paper-tape reader and punch, and a 500 line-per-minute printer (1500 line-per-minute using the hexadecimal character set). Storage was three

IBM 7000 The IBM 700/7000 series is a series of large-scale ( mainframe) computer systems that were made by IBM through the 1950s and early 1960s. The series includes several different, incompatible processor architectures. The 700s use vacuum-tube lo ...

series 1301 disk drives, each having two modules of 21.6 million characters apiece. One of the data products of MANIAC II was the table of numbers appearing in the book ''The 3-j and 6-j Symbols'' by Manuel Rotenberg, et al., published in 1959. Page 37 of that book contains a brief description of the implementation of the program on the computer, and the I/O devices used in the production of the book.Hoover was also the co-creator

External links

BRL report on MANIAC II
{{compu-hardware-stub One-of-a-kind computers Vacuum tube computers

See also

Further reading

External links