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 Computer programming, programmed to automatically Execution (computing), carry out sequences of arithmetic or logical operations (''computation''). Modern digital electronic computers can perform generic set ...

, built in 1957 for use at Los Alamos Scientific Laboratory. MANIAC II was built by the

University of California The University of California (UC) is a public university, public Land-grant university, land-grant research university, research university system in the U.S. state of California. Headquartered in Oakland, California, Oakland, the system is co ...

and the Los Alamos Scientific Laboratory and was 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 National Laboratory, Los Alamos Scientific Laboratory. It ...

. It used 2,850

vacuum tube A vacuum tube, electron tube, thermionic 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. It ...

s and 1,040

semiconductor A semiconductor is a material with electrical conductivity between that of a conductor and an insulator. Its conductivity can be modified by adding impurities (" doping") to its crystal structure. When two regions with different doping level ...

diode A diode is a two-Terminal (electronics), terminal electronic component that conducts electric current primarily in One-way traffic, one direction (asymmetric electrical conductance, conductance). It has low (ideally zero) Electrical resistance ...

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

transistor A transistor is a semiconductor device used to Electronic amplifier, amplify or electronic switch, switch electrical signals and electric power, power. It is one of the basic building blocks of modern electronics. It is composed of semicondu ...

s. It had 4,096

word A word is a basic element of language that carries semantics, meaning, can be used on its own, and is uninterruptible. Despite the fact that language speakers often have an intuitive grasp of what a word is, there is no consensus among linguist ...

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 remembe ...

magnetic-core memory In computing, magnetic-core memory is a form of random-access memory. It predominated for roughly 20 years between 1955 and 1975, and is often just called core memory, or, informally, core. Core memory uses toroids (rings) of a hard magneti ...

(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 Frederic Calland Williams, Freddie Williams and Tom Kilburn, is an early form of computer memory. It was the first Random-access memory, random-access digital storage devi ...

s (with 15 microsecond access time). The word size was 48 bits. Its average multiplication time was 180 microseconds and the average division time was 300 microseconds. By the time of its decommissioning, the computer was all solid-state, using a combination of RTL, DTL and TTL. 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 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 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.

External links

BRL report on MANIAC II
{{compu-hardware-stub One-of-a-kind computers Vacuum tube computers 48-bit computers

See also

Further reading

External links