IBM NORC
Encyclopedia
The IBM Naval Ordnance Research Calculator (NORC) was a one-of-a-kind first-generation (vacuum tube
) electronic computer
built by IBM
for the United States Navy
's Bureau of Ordnance
. 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.
The computer was presented to the US Navy on December 2, 1954. At the presentation ceremony, it calculated pi
to 3089 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
. It was their main computer until 1958, when more modern computers were acquired. It continued to be used until 1968. Its design influenced the IBM 701
and subsequent machines in the IBM 700 series
of computers.
Asteroid #1625 is named after the NORC, see Meanings of asteroid names (1501-2000)
.
or Williams tube
) for memory
which stored 2000 words, with an access time of 8 microseconds. Each word consisted of 16 decimal digits, using four bit
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 500 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 3600 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
, 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
arithmetic, which was used occasionally.
The main hardware consisted of 1982 pluggable unit
s, 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. A total of 9800 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 inch 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 35mm film camera 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.
Vacuum tube
In electronics, a vacuum tube, electron tube , or thermionic valve , reduced to simply "tube" or "valve" in everyday parlance, is a device that relies on the flow of electric current through a vacuum...
) electronic computer
Computer
A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem...
built by IBM
IBM
International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...
for the United States Navy
United States Navy
The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...
's Bureau of Ordnance
Bureau of Ordnance
The Bureau of Ordnance was the U.S. Navy's organization responsible for the procurement, storage, and deployment of all naval ordnance, between the years 1862 and 1959.-History:...
. 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.
The computer was presented to the US Navy on December 2, 1954. At the presentation ceremony, it calculated pi
Pi
' is a mathematical constant that is the ratio of any circle's circumference to its diameter. is approximately equal to 3.14. Many formulae in mathematics, science, and engineering involve , which makes it one of the most important mathematical constants...
to 3089 digits, which was a record at the time. The calculation took only 13 minutes. In 1955 NORC was moved to the Naval Proving Ground
Naval Surface Warfare Center Dahlgren Division
The United States Naval Surface Warfare Center, Dahlgren Division , named for Rear Admiral John A. Dahlgren, is located in Dahlgren, Virginia and is part of the Naval Surface Warfare Center. The NSWCDD was founded as the U.S...
at Dahlgren, Virginia
Dahlgren, Virginia
Dahlgren is a census-designated place in King George County, Virginia, United States. The population was 997 at the 2000 census. The community is located within the Northern Neck George Washington Birthplace American Viticultural Area winemaking appellation established by the United States...
. It was their main computer until 1958, when more modern computers were acquired. It continued to be used until 1968. Its design influenced the IBM 701
IBM 701
The IBM 701, known as the Defense Calculator while in development, was announced to the public on April 29, 1952, and was IBM’s first commercial scientific computer...
and subsequent machines in the IBM 700 series
IBM 700/7000 series
The IBM 700/7000 series was a series of large-scale computer systems made by IBM through the 1950s and early 1960s. The series included several different, incompatible processor architectures. The 700s used vacuum tube logic and were made obsolete by the introduction of the transistorized 7000s...
of computers.
Asteroid #1625 is named after the NORC, see Meanings of asteroid names (1501-2000)
Meanings of asteroid names (1501-2000)
This is a list of the sources of minor planet names. Those meanings marked with an asterisk are guesswork, and should be checked against Lutz D. Schmadel's Dictionary of Minor Planet Names or Paul Herget's The Names of the Minor Planets to ensure that the identification is correct...
.
Technology
The machine originally used electrostatic tubes (CRTCathode ray tube
The cathode ray tube is a vacuum tube containing an electron gun and a fluorescent screen used to view images. It has a means to accelerate and deflect the electron beam onto the fluorescent screen to create the images. The image may represent electrical waveforms , pictures , radar targets and...
or Williams tube
Williams tube
The Williams tube or the Williams-Kilburn tube , developed in about 1946 or 1947, was a cathode ray tube used to electronically store binary data....
) for memory
Computer storage
Computer data storage, often called storage or memory, refers to computer components and recording media that retain digital data. Data storage is one of the core functions and fundamental components of computers....
which stored 2000 words, with an access time of 8 microseconds. Each word consisted of 16 decimal digits, using four bit
Bit
A bit is the basic unit of information in computing and telecommunications; it is the amount of information stored by a digital device or other physical system that exists in one of two possible distinct states...
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 500 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 3600 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
Magnetic-core memory was the predominant form of random-access computer memory for 20 years . It uses tiny magnetic toroids , the cores, through which wires are threaded to write and read information. Each core represents one bit of information...
, 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
In computing, double precision is a computer number format that occupies two adjacent storage locations in computer memory. A double-precision number, sometimes simply called a double, may be defined to be an integer, fixed point, or floating point .Modern computers with 32-bit storage locations...
arithmetic, which was used occasionally.
The main hardware consisted of 1982 pluggable unit
Field Replaceable Unit
This article is primarily about FRUs in computers.A field replaceable unit is a circuit board, part or assembly that can be quickly and easily removed from a personal computer or other piece of electronic equipment, and replaced by the user or a technician without having to send the entire product...
s, 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. A total of 9800 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 inch 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 35mm film camera 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.
External links
- Naval Ordnance Research Calculator A THIRD SURVEY OF DOMESTIC ELECTRONIC DIGITAL COMPUTING SYSTEMS by Martin H. Weik ABERDEEN PROVING GROUND, MARYLAND