The IBM Naval Ordnance Research Calculator (NORC) was a one-of-a-kind first-generation (

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 potential difference has been applied. The type known as ...

) computer built by IBM for the

United States Navy The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage ...

Bureau of Ordnance The Bureau of Ordnance (BuOrd) was a United States Navy organization, which was responsible for the procurement, storage, and deployment of all naval weapons, between the years 1862 and 1959. History Congress established the Bureau in the Departme ...

. It went into service in December 1954 and was likely the most powerful computer at the time. The Naval Ordnance Research Calculator (NORC), was built at the Watson Scientific Computing Laboratory under the direction of

Wallace Eckert Wallace John Eckert (June 19, 1902 – August 24, 1971) was an American astronomer, who directed the Thomas J. Watson Astronomical Computing Bureau at Columbia University which evolved into the research division of IBM. Life Wallace John Eckert ...

. The computer was presented to the US Navy on December 2, 1954. At the presentation ceremony, it calculated pi to 3,089 digits, which was a record at the time. The calculation took only 13 minutes. In 1955, NORC was moved to the Naval Proving Ground at

Dahlgren, Virginia Dahlgren is an unincorporated community and census-designated place (CDP) in King George County, Virginia, United States. The population was 2,946 at the time of the 2020 census, up from 2,653 at the 2010 census, and up from 997 in 2000. History ...

. It was their main computer until 1958, when more modern computers were acquired. It continued to be used until 1963. Its design influenced the IBM 701 and subsequent machines in the IBM 700 series of computers.

Technology

The machine originally used Williams–Kilburn tubes for

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 ...

which stored 2,000 words electrostatically, with an access time of 8

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 ...

. Each word consisted of 16 decimal digits, using four

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 to represent each digit, plus two modulo-4 error-checking bits. A word could store a 13-digit number with sign and 2-digit index, or one instruction. NORC used four sets of 66 electrostatic tubes in parallel for memory. Each of the tubes in a set of 66 stored one bit of each of 500 words, so each of the four sets of 66 tubes stored 2,000 words. An upgrade to the addressing circuitry for the Williams tubes allowed memory per tube to be expanded from 500 bits to 900 bits, expanding the total memory to 3,600 words without needing to add any more Williams tubes. At some point the Williams tube memory was replaced with 20,000 words of

magnetic-core memory Magnetic-core memory was the predominant form of 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 hard magneti ...

, with an access time of 8 microseconds. The speed of the NORC was 15,000 operations per second. An addition took 15 microseconds, a multiplication took 31 microseconds, and a division took 227 microseconds, not counting memory access time and checking. It had the capacity to do

double precision Double-precision floating-point format (sometimes called FP64 or float64) is a floating-point number format, usually occupying 64 bits in computer memory; it represents a wide dynamic range of numeric values by using a floating radix point. Flo ...

arithmetic, which was used occasionally. The main hardware consisted of 1,982 pluggable units, each of which typically had several vacuum tubes plus supporting electronics. There were 62 types of pluggable units, but half of the circuitry used only six of the types and 80% of the circuitry used only 18 of the types. With 1,300 vacuum tubes in the three systems of the computer,Naval Ordnance Research Calculator
A THIRD SURVEY OF DOMESTIC ELECTRONIC DIGITAL COMPUTING SYSTEMS by Martin H. Weik ABERDEEN PROVING GROUND, MARYLAND the NORC had a total of 9,800 vacuum tubes and 10,000 crystal diodes were used. The NORC had eight magnetic tape units which were similar to the tape drives on the IBM 701 system. The reels were 8 inches in diameter and somewhat similar in appearance to a metal 16mm film reel. Unlike the 701 series tape drives, there was no operator control panel on the face of the machine, instead there were buttons placed on the top front of the machines that were used to initiate tape loading, rewinding, unloading, etc. The drives could read or write 71,500 characters per second. It had two printers that could print 150 lines per minute, although only one printer could be used at a time. It also had a card reader which could read 100 cards per minute, with four words stored per card. It also had a display unit which consisted of a CRT tube and a

35 mm film 35 mm may refer to: * 135 film, a type of still photography format commonly referred to as 35 mm film * 35 mm movie film 35 mm film is a film gauge used in filmmaking, and the film standard. In motion pictures that record on f ...

camera A camera is an optical instrument that can capture an image. Most cameras can capture 2D images, with some more advanced models being able to capture 3D images. At a basic level, most cameras consist of sealed boxes (the camera body), with a ...

which photographed the face of the tube and then sent the film through a develop and fix process before it was projected on a rear projection screen approximately 12 frames after the initial exposure. High volume data could also be recorded as text on the film, and employees of the Naval Weapons Laboratory would often work overtime in a darkened room scanning the films for obvious recording failures in critical data.

Awards and honors

The main-belt asteroid

1625 The NORC 1625 The NORC, provisional designation , is a carbonaceous asteroid from the outer region of the asteroid belt, approximately 55 kilometers in diameter. It was discovered on 1 September 1953, by Belgian astronomer Sylvain Arend at the Royal Obs ...

was named by

Paul Herget Paul Herget (January 30, 1908 – August 27, 1981) was an American astronomer and director of the Cincinnati Observatory, who established the Minor Planet Center after World War II. Career Herget taught astronomy at the University of Cincinn ...

in honor of the electronic calculator which significantly facilitated the elaborate orbital calculations of

minor planet According to the International Astronomical Union (IAU), a minor planet is an astronomical object in direct orbit around the Sun that is exclusively classified as neither a planet nor a comet. Before 2006, the IAU officially used the term ''mino ...

s at the time ().

References

Citations

* * * (No ISBN, Dewey decimal: 510.8 E19f). A contemporary book about the NORC. * *

External links

* Warner Pathé News about the NORC: * * {{DEFAULTSORT:Ibm Norc Cold War military computer systems of the United States

Norc NORC may refer to: Organizations * NORC (web service), a street view web service and company based in Romania * Guerrilla Army of the Poor, which went by the acronym NORC in its beginnings * National Opinion Research Center (NORC) at the Universit ...

One-of-a-kind computers Cold War military equipment of the United States Navy Decimal computers