UNIVAC is a line of electronic digital stored-program computers starting with the products of the Eckert–Mauchly Computer Corporation. The name was applied to a division of the Remington Rand company and successor organizations; the BINAC, built by the Eckert–Mauchly Computer Corporation, was the first general-purpose computer for commercial use. The descendants of the UNIVAC 1107 continue today as products of the Unisys company. J. Presper Eckert and John Mauchly built the ENIAC at the University of Pennsylvania's Moore School of Electrical Engineering between 1943 and 1946. A 1946 patent rights dispute with the university led Eckert and Mauchly to depart the Moore School to form the Electronic Control Company renamed Eckert-Mauchly Computer Corporation, based in Philadelphia, Pennsylvania; that company first built. Afterwards began the development of UNIVAC. UNIVAC was first intended for the Bureau of the Census, which paid for much of the development, was put in production. With the death of EMCC's chairman and chief financial backer Harry L. Straus in a plane crash on October 25, 1949, EMCC was sold to typewriter maker Remington Rand on February 15, 1950.
Eckert and Mauchly now reported to Leslie Groves, the retired army general who had managed the Manhattan Project. The most famous UNIVAC product was the UNIVAC I mainframe computer of 1951, which became known for predicting the outcome of the U. S. presidential election the following year. This incident is noteworthy because the computer predicted an Eisenhower landslide when traditional pollsters all called it for Adlai Stevenson; the numbers were so skewed that CBS's news boss in New York, decided the computer was in error and refused to allow the prediction to be read. Instead they showed some staged theatrics that suggested the computer was not responsive, announced it was predicting 8-7 odds for an Eisenhower win; when the predictions proved true and Eisenhower won a landslide within 1% of the initial prediction, Charles Collingwood, the on-air announcer, embarrassingly announced that they had covered up the earlier prediction. The United States Army requested a UNIVAC computer from Congress in 1951.
Colonel Wade Heavey explained to the Senate subcommittee that the national mobilization planning involved multiple industries and agencies: "This is a tremendous calculating process...there are equations that can not be solved by hand or by electrically operated computing machines because they involve millions of relationships that would take a lifetime to figure out." Heavey told the subcommittee it was needed to help with mobilization and other issues similar to the invasion of Normandy that were based on the relationships of various groups. Remington Rand had its own calculating machine lab in Norwalk and bought Engineering Research Associates in St. Paul, Minnesota. In 1953 or 1954 Remington Rand merged their Norwalk tabulating machine division, the ERA "scientific" computer division, the UNIVAC "business" computer division into a single division under the UNIVAC name; this annoyed those, with ERA and with the Norwalk laboratory. In 1955 Remington Rand merged with Sperry Corporation to become Sperry Rand.
The UNIVAC division of Remington Rand was renamed the Univac division of Sperry Rand. General Douglas MacArthur was chosen to head the company. In the 1960s, UNIVAC was one of the eight major American computer companies in an industry referred to as "IBM and the seven dwarfs" — a play on Snow White and the seven dwarfs, with IBM, by far the largest, being cast as Snow White and the other seven as being dwarfs: Burroughs, Univac, NCR, CDC, GE, RCA and Honeywell. In the 1970s, after GE sold its computer business to Honeywell and RCA sold its to Univac, the analogy to the seven dwarfs became less apt and the remaining small firms became known as the "BUNCH". To assist "corporate identity" the name was changed to Sperry Univac, along with Sperry Remington, Sperry New Holland, etc. In 1978, Sperry Rand, a conglomerate of various divisions, decided to concentrate on its computing interests and all of the unrelated divisions were sold; the company reverted to Sperry Corporation. In 1986, Sperry Corporation merged with Burroughs Corporation to become Unisys.
Since the 1986 merger of Burroughs and Sperry, Unisys has evolved from a computer manufacturer to a computer services and outsourcing firm, competing in the same marketplace as IBM, Electronic Data Systems, Computer Sciences Corporation. Unisys continues to design and manufacture enterprise class computers with the ClearPath and ES7000 server lines. In the course of its history, UNIVAC produced a number of separate model ranges. Early UNIVAC 1100 series models were vacuum tube computers; the original model range was the second commercial computer made in the United States. The main memory consisted of tanks of liquid mercury implementing delay line memory, arranged in 1000 words of 12 alphanumeric characters each; the first machine was delivered on 31 March 1951. The UNIVAC II was an improvement to the UNIVAC I that UNIVAC first delivered in 1958; the improvements included magnetic core memory of 2000 to 10000 words, UNISERVO II tape drives which could use either the old UNIVAC I metal tapes or the new PET film tapes, some circuits that were transistorized (
Machine code is a computer program written in machine language instructions that can be executed directly by a computer's central processing unit. Each instruction causes the CPU to perform a specific task, such as a load, a store, a jump, or an ALU operation on one or more units of data in CPU registers or memory. Machine code is a numerical language, intended to run as fast as possible, may be regarded as the lowest-level representation of a compiled or assembled computer program or as a primitive and hardware-dependent programming language. While it is possible to write programs directly in machine code, it is tedious and error prone to manage individual bits and calculate numerical addresses and constants manually. For this reason, programs are rarely written directly in machine code in modern contexts, but may be done for low level debugging, program patching, assembly language disassembly; the overwhelming majority of practical programs today are written in higher-level languages or assembly language.
The source code is translated to executable machine code by utilities such as compilers and linkers, with the important exception of interpreted programs, which are not translated into machine code. However, the interpreter itself, which may be seen as an executor or processor, performing the instructions of the source code consists of directly executable machine code. Machine code is by definition the lowest level of programming detail visible to the programmer, but internally many processors use microcode or optimise and transform machine code instructions into sequences of micro-ops, this is not considered to be a machine code per se; every processor or processor family has its own instruction set. Instructions are patterns of bits that by physical design correspond to different commands to the machine. Thus, the instruction set is specific to a class of processors using the same architecture. Successor or derivative processor designs include all the instructions of a predecessor and may add additional instructions.
A successor design will discontinue or alter the meaning of some instruction code, affecting code compatibility to some extent. Systems may differ in other details, such as memory arrangement, operating systems, or peripheral devices; because a program relies on such factors, different systems will not run the same machine code when the same type of processor is used. A processor's instruction set may have all instructions of the same length, or it may have variable-length instructions. How the patterns are organized varies with the particular architecture and also with the type of instruction. Most instructions have one or more opcode fields which specifies the basic instruction type and the actual operation and other fields that may give the type of the operand, the addressing mode, the addressing offset or index, or the actual value itself. Not all machines or individual instructions have explicit operands. An accumulator machine has a combined left operand and result in an implicit accumulator for most arithmetic instructions.
Other architectures have accumulator versions of common instructions, with the accumulator regarded as one of the general registers by longer instructions. A stack machine has all of its operands on an implicit stack. Special purpose instructions often lack explicit operands; this distinction between explicit and implicit operands is important in code generators in the register allocation and live range tracking parts. A good code optimizer can track implicit as well as explicit operands which may allow more frequent constant propagation, constant folding of registers and other code enhancements. A computer program is a list of instructions. A program's execution is done in order for the CPU, executing it to solve a specific problem and thus accomplish a specific result. While simple processors are able to execute instructions one after another, superscalar processors are capable of executing a variety of different instructions at once. Program flow may be influenced by special'jump' instructions that transfer execution to an instruction other than the numerically following one.
Conditional jumps are not depending on some condition. A much more readable rendition of machine language, called assembly language, uses mnemonic codes to refer to machine code instructions, rather than using the instructions' numeric values directly. For example, on the Zilog Z80 processor, the machine code 00000101, which causes the CPU to decrement the B processor register, would be represented in assembly language as DEC B; the MIPS architecture provides a specific example for a machine code whose instructions are always 32 bits long. The general type of instruction is given by the op field. J-type and I-type instructions are specified by op. R-type instructions include an additional field funct to determine the exact operation; the fields used in the
Free and open-source software
Free and open-source software is software that can be classified as both free software and open-source software. That is, anyone is licensed to use, copy and change the software in any way, the source code is shared so that people are encouraged to voluntarily improve the design of the software; this is in contrast to proprietary software, where the software is under restrictive copyright licensing and the source code is hidden from the users. FOSS maintains the software user's civil liberty rights. Other benefits of using FOSS can include decreased software costs, increased security and stability, protecting privacy and giving users more control over their own hardware. Free and open-source operating systems such as Linux and descendants of BSD are utilized today, powering millions of servers, desktops and other devices. Free-software licenses and open-source licenses are used by many software packages; the free-software movement and the open-source software movement are online social movements behind widespread production and adoption of FOSS.
"Free and open-source software" is an umbrella term for software, considered both Free software and open-source software. FOSS allows the user to inspect the source code and provides a high level of control of the software's functions compared to proprietary software; the term "free software" does not refer to the monetary cost of the software at all, but rather whether the license maintains the software user's civil liberties. There are a number of related terms and abbreviations for free and open-source software, or free/libre and open-source software. Although there is a complete overlap between free-software licenses and open-source-software licenses, there is a strong philosophical disagreement between the advocates of these two positions; the terminology of FOSS or "Free and Open-source software" was created to be a neutral on these philosophical disagreements between the FSF and OSI and have a single unified term that could refer to both concepts. As the Free Software Foundation explains the philosophical difference between free software and open-source software: "The two terms describe the same category of software, but they stand for views based on fundamentally different values.
Open-source is a development methodology. For the free-software movement, free software is an ethical imperative, essential respect for the users' freedom. By contrast, the philosophy of open-source considers issues in terms of how to make software “better”—in a practical sense only." In parallel to this the Open Source Initiative considers many free-software licenses to be open source. These include the latest versions of the FSF's three main licenses: the GPL, the Lesser General Public License, the GNU Affero General Public License. Richard Stallman's Free Software Definition, adopted by the Free Software Foundation, defines free software as a matter of liberty not price, it upholds the Four Essential Freedoms; the earliest-known publication of the definition of his free-software idea was in the February 1986 edition of the FSF's now-discontinued GNU's Bulletin publication. The canonical source for the document is in the philosophy section of the GNU Project website; as of August 2017, it is published there in 40 languages.
To meet the definition of "free software", the FSF requires the software's licensing rights what the FSF respect the civil liberties / human rights of what the FSF calls the software user's "Four Essential Freedoms". The freedom to run the program as you wish, for any purpose; the freedom to study how the program works, change it so it does your computing as you wish. Access to the source code is a precondition for this; the freedom to redistribute copies. The freedom to distribute copies of your modified versions to others. By doing this you can give the whole community a chance to benefit from your changes. Access to the source code is a precondition for this; the open-source-software definition is used by the Open Source Initiative to determine whether a software license qualifies for the organization's insignia for Open-source software. The definition was based on the Debian Free Software Guidelines and adapted by Bruce Perens. Perens did not base his writing on the Four Essential Freedoms of free software from the Free Software Foundation, which were only available on the web.
Perens subsequently stated that he felt Eric Raymond's promotion of Open-source unfairly overshadowed the Free Software Foundation's efforts and reaffirmed his support for Free software. In the following 2000s, he spoke about open source again. In the 1950s through the 1980s, it was common for computer users to have the source code for all programs they used, the permission and ability to modify it for their own use. Software, including source code, was shared by individuals who used computers as public domain software. Most companies had a business model based on hardware sales, provided or bundled software with hardware, free of charge. By the late 1960s, the prevailing business model around software was changing. A growing and evolving software industry was competing with the hardware manufacturer's bundled software products. Leased machines required software support while providing n
Grace Brewster Murray Hopper was an American computer scientist and United States Navy rear admiral. One of the first programmers of the Harvard Mark I computer, she was a pioneer of computer programming who invented one of the first linkers, she popularized the idea of machine-independent programming languages, which led to the development of COBOL, an early high-level programming language still in use today. She always dreamed of a programming language written in English. Prior to joining the Navy, Hopper earned a Ph. D. in mathematics from Yale University and was a professor of mathematics at Vassar College. Hopper attempted to enlist in the Navy during World War II but was rejected because she was 34 years old, she instead joined the Navy Reserves. Hopper began her computing career in 1944 when she worked on the Harvard Mark I team led by Howard H. Aiken. In 1949, she joined the Eckert–Mauchly Computer Corporation and was part of the team that developed the UNIVAC I computer. At Eckert–Mauchly she began developing the compiler.
She believed. Her compiler converted English terms into machine code understood by computers. By 1952, Hopper had finished her program linker, written for the A-0 System. During her wartime service, she co-authored three papers based on her work on the Harvard Mark 1. In 1954, Eckert–Mauchly chose Hopper to lead their department for automatic programming, she led the release of some of the first compiled languages like FLOW-MATIC. In 1959, she participated in the CODASYL consortium, which consulted Hopper to guide them in creating a machine-independent programming language; this led to the COBOL language, inspired by her idea of a language being based on English words. In 1966, she retired from the Naval Reserve, she retired from the Navy in 1986 and found work as a consultant for the Digital Equipment Corporation, sharing her computing experiences. Owing to her accomplishments and her naval rank, she was sometimes referred to as "Amazing Grace"; the U. S. Navy Arleigh Burke-class guided-missile destroyer USS Hopper was named for her, as was the Cray XE6 "Hopper" supercomputer at NERSC.
During her lifetime, Hopper was awarded 40 honorary degrees from universities across the world. A college at Yale University was renamed in her honor. In 1991, she received the National Medal of Technology. On November 22, 2016, she was posthumously awarded the Presidential Medal of Freedom by President Barack Obama. Hopper was born in New York City, she was the eldest of three children. Her parents, Walter Fletcher Murray and Mary Campbell Van Horne, were of Scottish and Dutch descent, attended West End Collegiate Church, her great-grandfather, Alexander Wilson Russell, an admiral in the US Navy, fought in the Battle of Mobile Bay during the Civil War. Grace was curious as a child. At the age of seven, she decided to determine how an alarm clock worked and dismantled seven alarm clocks before her mother realized what she was doing. For her preparatory school education, she attended the Hartridge School in New Jersey. Hopper was rejected for early admission to Vassar College at age 16, but she was admitted the following year.
She graduated Phi Beta Kappa from Vassar in 1928 with a bachelor's degree in mathematics and physics and earned her master's degree at Yale University in 1930. In 1934, she earned a Ph. D. in mathematics from Yale under the direction of Øystein Ore. Her dissertation, "New Types of Irreducibility Criteria", was published that same year. Hopper began teaching mathematics at Vassar in 1931, was promoted to associate professor in 1941, she was married to New York University professor Vincent Foster Hopper from 1930 until their divorce in 1945. She chose to retain his surname. Hopper had tried to enlist in the Navy early in World War II, she was rejected for multiple reasons. At age 34, she was too old to enlist, her weight to height ratio was too low, she was denied on the basis that her job as a mathematician and mathematics professor at Vassar College was valuable to the war effort. During the war in 1943, Hopper obtained a leave of absence from Vassar and was sworn into the United States Navy Reserve.
She had to get an exemption to enlist. She reported in December and trained at the Naval Reserve Midshipmen's School at Smith College in Northampton, Massachusetts. Hopper graduated first in her class in 1944, was assigned to the Bureau of Ships Computation Project at Harvard University as a lieutenant, junior grade, she served on the Mark I computer programming staff headed by Howard H. Aiken. Hopper and Aiken co-authored three papers on the Mark I known as the Automatic Sequence Controlled Calculator. Hopper's request to transfer to the regular Navy at the end of the war was declined due to her advanced age of 38, she continued to serve in the Navy Reserve. Hopper remained at the Harvard Computation Lab until 1949, turning down a full professorship at Vassar in favor of working as a research fellow under a Navy contract at Harvard. In 1949, Hopper became an employee of the Eckert–Mauchly Computer Corporation as a senior mathematician and joined the team developing the UNIVAC I. Hopper served as UNIVAC director of Automatic Programming Development for Remington Rand.
The UNIVAC was the first known large-scale electronic computer to be on the market in 1950, was more competitive at processing information th
The UNIVAC I was the first commercial computer produced in the United States. It was designed principally by J. Presper Eckert and John Mauchly, the inventors of the ENIAC. Design work was started by their company, Eckert–Mauchly Computer Corporation, was completed after the company had been acquired by Remington Rand. In the years before successor models of the UNIVAC I appeared, the machine was known as "the UNIVAC"; the first Univac was accepted by the United States Census Bureau on March 31, 1951, was dedicated on June 14 that year. The fifth machine was used by CBS to predict the result of the 1952 presidential election. With a sample of just 1% of the voting population it famously predicted an Eisenhower landslide while the conventional wisdom favored Stevenson; the UNIVAC I was the first American computer designed at the outset for business and administrative use with fast execution of simple arithmetic and data transport operations, as opposed to the complex numerical calculations required of scientific computers.
As such, the UNIVAC competed directly against punch-card machines, though the UNIVAC could neither read nor punch cards. That shortcoming hindered sales to companies concerned about the high cost of manually converting large quantities of existing data stored on cards; this was corrected by adding offline card processing equipment, the UNIVAC Card to Tape converter and the UNIVAC 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. To promote sales, the company joined with CBS to have UNIVAC I predict the result of the 1952 Presidential election. UNIVAC I predicted Eisenhower would have a landslide victory over Adlai Stevenson whom the pollsters favored; the CBS crew was so certain. As the election continued and it became clear it was correct all along, the announcer admitted their sleight of hand and the machine became famous; the result was a greater public awareness of computing technology, from on computerized predictions were a must-have part of election night broadcasts.
The first contracts were with government agencies such as the Census Bureau, the U. S. Air Force, the U. S. Army Map Service. Contracts were signed by the ACNielsen Company, the Prudential Insurance Company. 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 shipped until the following December, because, as the sole set-up model, it was needed for demonstration purposes, the company was apprehensive about the difficulties of dismantling 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 Originally priced at US$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 built and delivered. The UNIVAC I was too expensive for most universities, 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, the University of Pennsylvania, Case Institute of Technology in Cleveland, Ohio. A few UNIVAC I systems stayed in service; the Census Bureau used its two systems until 1963, amounting to 12 and nine years of service, respectively. Sperry Rand itself used two systems in Buffalo, New York until 1968; the insurance company Life and Casualty of Tennessee used its system until 1970, totaling over 13 years of service. UNIVAC I used about 5,000 vacuum tubes, weighed 16,686 pounds, consumed 125 kW, could perform about 1,905 operations per second running on a 2.25 MHz clock. The Central Complex alone 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. The main memory consisted of 1000 words of 12 characters.
When representing numbers, they were written as 11 decimal digits plus sign. The 1000 words of memory consisted of 100 channels of 10-word mercury delay line registers; the input/output buffers were 60 words each, consisting of 12 channels of 10-word mercury delay line registers. There are six channels of 10-word mercury delay line registers as spares. With modified circuitry, seven more channels control the temperature of the seven mercury tanks, one more channel is used for the 10 word "Y" register; the total of 126 mercury channels is contained in the seven mercury tanks mounted on the backs of sections MT, MV, MX, NT, NV, NX, 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 quartz piezo-electric crystals mounted at opposite ends. An intermediate frequency chassis, connected to the receiving crystal, containing amplifiers and compensating delay, mounted on the shell of the mercury tank.
A recirculation chassis, containing cathode follower, pulse former and retimer, which drives the transmitting crystal