UNIVAC I
Encyclopedia
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
. It was designed principally by J. Presper Eckert
J. Presper Eckert
John Adam Presper "Pres" Eckert Jr. was an American electrical engineer and computer pioneer. With John Mauchly he invented the first general-purpose electronic digital computer , presented the first course in computing topics , founded the first commercial computer company , and...
and John Mauchly
John Mauchly
John William Mauchly was an American physicist who, along with J. Presper Eckert, designed ENIAC, the first general purpose electronic digital computer, as well as EDVAC, BINAC and UNIVAC I, the first commercial computer made in the United States.Together they started the first computer company,...
, the inventors of the ENIAC
ENIAC
ENIAC was the first general-purpose electronic computer. It was a Turing-complete digital computer capable of being reprogrammed to solve a full range of computing problems....
. Design work was begun by their company, Eckert-Mauchly Computer Corporation
Eckert-Mauchly Computer Corporation
The Eckert–Mauchly Computer Corporation was founded by J. Presper Eckert and John Mauchly, and was incorporated on December 22, 1947. After building the ENIAC at the University of Pennsylvania, Eckert and Mauchly formed EMCC to build new computer designs for commercial and military applications...
, and was completed after the company had been acquired by Remington Rand
Remington Rand
Remington Rand was an early American business machines manufacturer, best known originally as a typewriter manufacturer and in a later incarnation as the manufacturer of the UNIVAC line of mainframe computers but with antecedents in Remington Arms in the early nineteenth century. For a time, the...
(which later became part of Sperry
Sperry Corporation
Sperry Corporation was a major American equipment and electronics company whose existence spanned more than seven decades of the twentieth century...
, now Unisys
Unisys
Unisys Corporation , headquartered in Blue Bell, Pennsylvania, United States, and incorporated in Delaware, is a long established business whose core products now involves computing and networking.-History:...
). In the years before successor models of the UNIVAC I appeared, the machine was simply known as "the UNIVAC".
The first UNIVAC was delivered to the United States Census Bureau
United States Census Bureau
The United States Census Bureau is the government agency that is responsible for the United States Census. It also gathers other national demographic and economic data...
on March 31, 1951, and was dedicated on June 14 that year. The fifth machine (built for the U.S. Atomic Energy Commission
United States Atomic Energy Commission
The United States Atomic Energy Commission was an agency of the United States government established after World War II by Congress to foster and control the peace time development of atomic science and technology. President Harry S...
) was used by CBS
CBS
CBS Broadcasting Inc. is a major US commercial broadcasting television network, which started as a radio network. The name is derived from the initials of the network's former name, Columbia Broadcasting System. The network is sometimes referred to as the "Eye Network" in reference to the shape of...
to predict the result of the 1952 presidential election. With a sample of just 1% of the voting population it correctly predicted that Dwight Eisenhower would win.
Market positioning
As well as being the first American commercial computer, the UNIVAC I was the first American computer designed at the outset for business and administrative use (i.e., for the fast execution of large numbers of relatively simple arithmetic and data transport operations, as opposed to the complex numerical calculations required by scientific computers). As such the UNIVAC competed directly against punch-cardPunched card
A punched card, punch card, IBM card, or Hollerith card is a piece of stiff paper that contains digital information represented by the presence or absence of holes in predefined positions...
machines (mainly made 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...
), but oddly enough the UNIVAC originally had no means of either reading or punching cards (which initially hindered sales to some companies with large quantities of data on cards, due to potential manual conversion costs). This was corrected by adding offline card processing equipment, the UNIVAC Card to Tape converter
UNIVAC Card to Tape converter
The UNIVAC Card to Tape converter read punched cards at 240 cards per minute and wrote their data on metal UNIVAC magnetic tape using a UNISERVO tape drive.-External links:* Has photo of Card to Tape Converter...
and the UNIVAC Tape to Card converter
UNIVAC Tape to Card converter
The UNIVAC Tape to Card converter read metal UNIVAC magnetic tape using a UNISERVO tape drive and punched the data on punched cards at 120 cards per minute.-External links:* Has photo of Tape to Card Converter...
, to transfer data between cards and UNIVAC magnetic tapes. However, the early market share of the UNIVAC I was lower than the Remington Rand Company wished. In an effort to increase market share, the company joined with CBS to have UNIVAC I predict the result of the 1952 Presidential election. UNIVAC I predicted Ike Eisenhower would have a landslide victory over Adlai Stevenson who the pollsters favored. The result for UNIVAC I was a greater public awareness in computing technology.
Installations
United States Census Bureau
The United States Census Bureau is the government agency that is responsible for the United States Census. It also gathers other national demographic and economic data...
, the U.S. Air Force
United States Air Force
The United States Air Force is the aerial warfare service branch of the United States Armed Forces and one of the American uniformed services. Initially part of the United States Army, the USAF was formed as a separate branch of the military on September 18, 1947 under the National Security Act of...
, and the U.S. Army Map Service. Contracts were also signed by the ACNielsen Company
ACNielsen
ACNielsen is a global marketing research firm, with worldwide headquarters in New York City. Regional headquarters for North America are located in Schaumburg, Illinois. As of May 2010, it is part of The Nielsen Company.-History:...
, and the Prudential Insurance Company
Prudential Financial
The Prudential Insurance Company of America , also known as Prudential Financial, Inc., is a Fortune Global 500 and Fortune 500 company whose subsidiaries provide insurance, investment management, and other financial products and services to both retail and institutional customers throughout the...
. Following the sale of Eckert-Mauchly Computer Corporation to Remington Rand, due to the cost overruns on the project, Remington Rand convinced Nielsen and Prudential to cancel their contracts.
The first sale, to the Census Bureau, was marked with a formal ceremony on March 31, 1951, at the Eckert–Mauchly Division's factory at 3747 Ridge Avenue, Philadelphia. The machine was not actually shipped until the following December, because, as the sole fully set-up model, it was needed for demonstration purposes, and the company was apprehensive about the difficulties of dismantling, transporting, and reassembling the delicate machine. As a result, the first installation was with the second computer, delivered to the Pentagon in June 1952.
UNIVAC installations, 1951–1954
| Date | Customer | Comments |
|---|---|---|
| 1951 | U.S. Census Bureau, Suitland, MD | Not shipped until 1952 |
| 1952 | U.S. Air Force | Pentagon The Pentagon The Pentagon is the headquarters of the United States Department of Defense, located in Arlington County, Virginia. As a symbol of the U.S. military, "the Pentagon" is often used metonymically to refer to the Department of Defense rather than the building itself.Designed by the American architect... , Arlington, VA |
| 1952 | U.S. Army Map Service National Geospatial-Intelligence Agency The National Geospatial-Intelligence Agency is an agency of the federal government of the United States with the primary mission of collecting, analyzing and distributing geospatial intelligence in support of national security. NGA was formerly known as the National Imagery and Mapping Agency ... |
Washington, DC. Operated at factory April-September, 1952 |
| 1953 | New York University New York University New York University is a private, nonsectarian research university based in New York City. NYU's main campus is situated in the Greenwich Village section of Manhattan... (for the Atomic Energy Commission) |
New York, NY |
| 1953 | Atomic Energy Commission United States Atomic Energy Commission The United States Atomic Energy Commission was an agency of the United States government established after World War II by Congress to foster and control the peace time development of atomic science and technology. President Harry S... |
Livermore, CA |
| 1953 | U.S. Navy | David W. Taylor Model Basin David Taylor Model Basin The David Taylor Model Basin is one of the largest ship model basins — test facilities for the development of ship design — in the world... , Bethesda, MD |
| 1954 | Remington Rand Remington Rand Remington Rand was an early American business machines manufacturer, best known originally as a typewriter manufacturer and in a later incarnation as the manufacturer of the UNIVAC line of mainframe computers but with antecedents in Remington Arms in the early nineteenth century. For a time, the... |
Sales office, New York, NY |
| 1954 | General Electric General Electric General Electric Company , or GE, is an American multinational conglomerate corporation incorporated in Schenectady, New York and headquartered in Fairfield, Connecticut, United States... |
Appliance Division, Louisville, KY. First business sale. |
| 1954 | Metropolitan Life | New York, NY |
| 1954 | U.S. Air Force | Wright-Patterson AFB, Dayton, OH |
| 1954 | U.S. Steel U.S. Steel The United States Steel Corporation , more commonly known as U.S. Steel, is an integrated steel producer with major production operations in the United States, Canada, and Central Europe. The company is the world's tenth largest steel producer ranked by sales... |
Pittsburgh, PA |
| 1954 | Du Pont | Wilmington, DE |
| 1954 | U.S. Steel U.S. Steel The United States Steel Corporation , more commonly known as U.S. Steel, is an integrated steel producer with major production operations in the United States, Canada, and Central Europe. The company is the world's tenth largest steel producer ranked by sales... |
Gary, IN |
| 1954 | Franklin Life Insurance | Springfield, IL |
| 1954 | Westinghouse Westinghouse Electric (1886) Westinghouse Electric was an American manufacturing company. It was founded in 1886 as Westinghouse Electric Company and later renamed Westinghouse Electric Corporation by George Westinghouse. The company purchased CBS in 1995 and became CBS Corporation in 1997... |
Pittsburgh, PA |
| 1954 | Pacific Mutual Life Insurance Pacific Life Pacific Life Insurance Company is an insurance company providing life insurance products, annuities, and mutual funds, and offers to individuals, businesses, and pension plans a variety of investment products and services. Pacific Life also counts more than half of the 100 largest U.S... |
Los Angeles, CA |
| 1954 | Sylvania Electric Sylvania Electric Products Sylvania Electric Products was a U.S. manufacturer of diverse electrical equipment, including at various times radio transceivers, vacuum tubes, semiconductors, and mainframe computers... |
New York, NY |
| 1954 | Consolidated Edison Consolidated Edison Consolidated Edison, Inc. is one of the largest investor-owned energy companies in the United States, with approximately $14 billion in annual revenues and $36 billion in assets... |
New York, NY |
Originally priced at US$
United States dollar
The United States dollar , also referred to as the American dollar, is the official currency of the United States of America. It is divided into 100 smaller units called cents or pennies....
159,000, the UNIVAC I rose in price until they were between $1,250,000 and $1,500,000. A total of 46 systems were eventually built and delivered.
The UNIVAC I was too expensive for most universities, and Sperry Rand, unlike companies such as IBM, was not strong enough financially to afford to give many away. However Sperry Rand donated UNIVAC I systems to Harvard University
Harvard University
Harvard University is a private Ivy League university located in Cambridge, Massachusetts, United States, established in 1636 by the Massachusetts legislature. Harvard is the oldest institution of higher learning in the United States and the first corporation chartered in the country...
(1956), the University of Pennsylvania
University of Pennsylvania
The University of Pennsylvania is a private, Ivy League university located in Philadelphia, Pennsylvania, United States. Penn is the fourth-oldest institution of higher education in the United States,Penn is the fourth-oldest using the founding dates claimed by each institution...
(1957), and Case Institute of Technology in Cleveland, Ohio
Cleveland, Ohio
Cleveland is a city in the U.S. state of Ohio and is the county seat of Cuyahoga County, the most populous county in the state. The city is located in northeastern Ohio on the southern shore of Lake Erie, approximately west of the Pennsylvania border...
(1957); the UNIVAC I at Case was still operable in 1965 but had been supplanted by a UNIVAC 1107.
A few UNIVAC I systems stayed in service long after they were obsoleted by advancing technology. The Census Bureau used its two systems until 1963, amounting to twelve and nine years of service, respectively. Sperry Rand itself used two systems in Buffalo, New York
Buffalo, New York
Buffalo is the second most populous city in the state of New York, after New York City. Located in Western New York on the eastern shores of Lake Erie and at the head of the Niagara River across from Fort Erie, Ontario, Buffalo is the seat of Erie County and the principal city of the...
until 1968. The insurance company Life and Casualty of Tennessee used its system until 1970, totaling over thirteen years of service.
Technical description
Major physical features
UNIVAC I used 5,200 vacuum tubeVacuum 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...
s, weighed 29000 pounds (13.2 MT), consumed 125 kW, and could perform about 1,905 operations per second running on a 2.25 MHz clock. The Central Complex alone (i.e. the processor and memory unit) was 4.3 m by 2.4 m by 2.6 m high. The complete system occupied more than 35.5 m² of floor space.
Main memory details
The main memory consisted of 1000 words of 12 characters. When representing numbers, they were written as 11 decimalDecimal
The decimal numeral system has ten as its base. It is the numerical base most widely used by modern civilizations....
digits plus sign
Signed number representations
In computing, signed number representations are required to encode negative numbers in binary number systems.In mathematics, negative numbers in any base are represented by prefixing them with a − sign. However, in computer hardware, numbers are represented in binary only without extra...
. The 1000 words of memory consisted of 100 channels of 10 word mercury
Mercury (element)
Mercury is a chemical element with the symbol Hg and atomic number 80. It is also known as quicksilver or hydrargyrum...
delay line
Delay line memory
Delay line memory was a form of computer memory used on some of the earliest digital computers. Like many modern forms of electronic computer memory, delay line memory was a refreshable memory, but as opposed to modern random-access memory, delay line memory was serial-access...
registers. The input/output
Input/output
In computing, input/output, or I/O, refers to the communication between an information processing system , and the outside world, possibly a human, or another information processing system. Inputs are the signals or data received by the system, and outputs are the signals or data sent from it...
buffers were 60 words each, consisting of 12 channels of 10 word mercury delay line registers. There are 6 channels of 10 word mercury delay line registers as spares. With modified circuitry, 7 more channels control the temperature of the 7 mercury tanks, and one more channel is used for the 10 word "Y" register. The total of 126 mercury channels is contained in the 7 mercury tanks mounted on the backs of sections MT, MV, MX, NT, NV, NX, and GV. Each mercury tank is divided into 18 mercury channels.
Each 10 word mercury delay line channel is made up of three sections:
- A channel in a column of mercury, with receiving and transmitting quartzQuartzQuartz is the second-most-abundant mineral in the Earth's continental crust, after feldspar. It is made up of a continuous framework of SiO4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall formula SiO2. There are many different varieties of quartz,...
piezo-electric crystalCrystalA crystal or crystalline solid is a solid material whose constituent atoms, molecules, or ions are arranged in an orderly repeating pattern extending in all three spatial dimensions. The scientific study of crystals and crystal formation is known as crystallography...
s mounted at opposite ends. - An intermediate frequency chassis, connected to the receiving crystal, containing amplifiers, detector, and compensating delay, mounted on the shell of the mercury tank.
- A recirculation chassis, containing cathode follower, pulse former and retimer, modulator, which drives the transmitting crystal, and input, clear, and memory-switch gates, mounted in the sections adjacent to the mercury tanks.
Instructions and data
InstructionsInstruction set
An instruction set, or instruction set architecture , is the part of the computer architecture related to programming, including the native data types, instructions, registers, addressing modes, memory architecture, interrupt and exception handling, and external I/O...
were 6 alphanumeric
Alphanumeric
Alphanumeric is a combination of alphabetic and numeric characters, and is used to describe the collection of Latin letters and Arabic digits or a text constructed from this collection. There are either 36 or 62 alphanumeric characters. The alphanumeric character set consists of the numbers 0 to...
characters, packed 2 per word. The addition time was 525 microseconds and the multiplication time was 2150 microseconds. A non-standard modification called "Overdrive" did exist, that allowed for three 4-character instructions per word under some circumstances. (Ingerman's simulator for the UNIVAC, referenced below, also makes this modification available.)
Digits were represented internally using excess-3
Excess-3
Excess-3 binary-coded decimal ' or Stibitz code, also called biased representation or Excess-N, is a complementary BCD code and numeral system it is used on some older computers that uses a pre-specified number N as a biasing value. It is a way to represent values with a balanced number of positive...
("XS3") binary coded decimal (BCD) arithmetic with 6 bits per digit using the same value as the digits of the alphanumeric character set (and one parity bit
Parity bit
A parity bit is a bit that is added to ensure that the number of bits with the value one in a set of bits is even or odd. Parity bits are used as the simplest form of error detecting code....
per digit for error checking), allowing 11 digit signed magnitude numbers. But with the exception of one or two machine instructions, UNIVAC was considered by programmers to be a decimal machine, not a binary machine, and the binary representation of the characters was irrelevant. If a non-digit character was encountered in a position during an arithmetic operation the machine passed it unchanged to the output, and any carry into the non-digit was lost. (Note, however, that a peculiarity of UNIVAC I's addition/subtraction circuitry was that the "ignore", space, and minus characters were occasionally treated as numeric, with values of -3, -2, and -1 respectively, and the apostrophe, ampersand, and left parenthesis were occasionally treated as numeric, with values 10, 11, and 12.)
Input/output
Besides the operator's console, the only I/O devices connected to the UNIVAC I were up to 10 UNISERVOUNISERVO
The UNISERVO tape drive was the primary I/O device on the UNIVAC I computer. Its place in history is assured as it was the first tape drive for a commercially sold computer....
tape drives, a Remington Standard electric typewriter and a Tektronix
Tektronix
Tektronix, Inc. is an American company best known for its test and measurement equipment such as oscilloscopes, logic analyzers, and video and mobile test protocol equipment. In November 2007, Tektronix became a subsidiary of Danaher Corporation....
oscilloscope
Oscilloscope
An oscilloscope is a type of electronic test instrument that allows observation of constantly varying signal voltages, usually as a two-dimensional graph of one or more electrical potential differences using the vertical or 'Y' axis, plotted as a function of time,...
. The UNISERVO was the first commercial computer tape drive commercially sold. It used data density 128 bits per inch (with real transfer rate 7,200 characters per second) on magnetically plated phosphor bronze tapes. The UNISERVO could also read and write UNITYPER created tapes at 20 bits per inch. The UNITYPER was an offline typewriter to tape device, used by programmers and for minor data editing. Backward and forward tape read and write operations were possible on the UNIVAC and were fully overlapped with instruction execution, permitting high system throughput in typical sort/merge data processing applications. Large volumes of data could be inputted via magnetic tapes created on offline card to tape system and outputted via a separate offline tape to printer system. The operators console had three columns of decimal coded switches that allowed any of the 1000 memory locations to be displayed on the oscilloscope. Since the mercury delay line memory stored bits in a serial format, a programmer or operator could monitor any memory location continuously and with sufficient patience, decode its contents as displayed on the scope. The on-line typewriter was typically used for announcing program breakpoints, checkpoints, and for memory dumps.
See also
- List of UNIVAC products
- History of computing hardwareHistory of computing hardwareThe history of computing hardware is the record of the ongoing effort to make computer hardware faster, cheaper, and capable of storing more data....
External links
- UNIVAC Conference Oral history on 17-18 May 1990. Charles Babbage Institute, University of Minnesota, Minneapolis. 171-page transcript of oral history with computer pioneers, including Jean Bartik, involved with the Univac computer, held on 17–18 May 1990. The meeting involved 25 engineers, programmers, marketing representatives, and salesmen who were involved with the UNIVAC, as well as representatives from users such as General Electric, Arthur Andersen, and the U.S. Census.
- Margaret R. Fox Papers, 1935-1976, Charles Babbage InstituteCharles Babbage InstituteThe Charles Babbage Institute is a research center at the University of Minnesota specializing in the history of information technology, particularly the history since 1935 of digital computing, programming/software, and computer networking....
, University of Minnesota. collection contains reports, including the original report on the ENIAC, UNIVAC, and many early in-house National Bureau of Standards (NBS) activity reports; memoranda on and histories of SEAC, SWAC, and DYSEAC; programming instructions for the UNIVAC, LARC, and MIDAC; patent evaluations and disclosures relevant to computers; system descriptions; speeches and articles written by Margaret Fox's colleagues; and correspondence of Samuel Alexander, Margaret Fox, and Samuel Williams. - John W. Mauchly, Sperry Univac Point of View address, 13 November 1973, Rome, Italy at Charles Babbage InstituteCharles Babbage InstituteThe Charles Babbage Institute is a research center at the University of Minnesota specializing in the history of information technology, particularly the history since 1935 of digital computing, programming/software, and computer networking....
, University of Minnesota, Minneapolis. Discusses challenges in building ENIACENIACENIAC was the first general-purpose electronic computer. It was a Turing-complete digital computer capable of being reprogrammed to solve a full range of computing problems....
at Moore School of Electrical EngineeringMoore School of Electrical EngineeringThe Moore School of Electrical Engineering at the University of Pennsylvania came into existence as a result of an endowment from Alfred Fitler Moore on June 4, 1923. It was granted to Penn's School of Electrical Engineering, located in the Towne Building...
, University of Pennsylvania; also describes the Eckert-Mauchly Computer CorporationEckert-Mauchly Computer CorporationThe Eckert–Mauchly Computer Corporation was founded by J. Presper Eckert and John Mauchly, and was incorporated on December 22, 1947. After building the ENIAC at the University of Pennsylvania, Eckert and Mauchly formed EMCC to build new computer designs for commercial and military applications...
and the UNIVAC 1 computer - UNIVAC I documentation – From computer documentation repository www.bitsavers.org
- Unisys History Newsletter, Volume 5, Number 1 – From Randy Carpenter's home page at Georgia Tech
- The UNIVAC and the Legacy of the ENIAC – From the University of Pennsylvania Library (PENN UNIVERSITY/exhibitions)
- UNIVAC 1 Computer System – By Allan G. Reiter, formerly of the ERA division of Remington Rand
- UNIVAC Simulator 1.2 – By Peter Zilahy Ingerman; Shareware simulator of the UNIVAC I and II
- Core memory slide show – This slide show contains a photo of a 1951 core memory module for a UNIVAC I
- Remington-Rand Presents UNIVAC – Promotional film from the collection of the Computer History Museum, Mountain View, California
- "Want To Buy A Brain", May 1949, Popular Science early illustrated article on the UNIVAC for the general public