The UNIVAC 1103 or ERA 1103, a successor to the UNIVAC 1101, was a

computer system A computer is a machine that can be programmed to carry out sequences of arithmetic or logical operations ( computation) automatically. Modern digital electronic computers can perform generic sets of operations known as programs. These prog ...

Engineering Research Associates Engineering Research Associates, commonly known as ERA, was a pioneering computer firm from the 1950s. ERA became famous for their numerical computers, but as the market expanded they became better known for their drum memory systems. They were ev ...

and built by the Remington Rand corporation in October 1953. It was the first computer for which

Seymour Cray Seymour Roger Cray (September 28, 1925 – October 5, 1996
) was an American

Navy A navy, naval force, or maritime force is the branch of a nation's armed forces principally designated for naval and amphibious warfare; namely, lake-borne, riverine, littoral, or ocean-borne combat operations and related functions. It in ...

asked Engineering Research Associates to design a more powerful machine. This project became Task 29, and the computer was designated ''Atlas II''. In 1952, Engineering Research Associates asked the Armed Forces Security Agency (the predecessor of the

NSA The National Security Agency (NSA) is a national-level intelligence agency of the United States Department of Defense, under the authority of the Director of National Intelligence (DNI). The NSA is responsible for global monitoring, collec ...

) for approval to sell the ''Atlas II'' commercially. Permission was given, on the condition that several specialized instructions would be removed. The commercial version then became the UNIVAC 1103. Because of

security classification Classified information is material that a government body deems to be sensitive information that must be protected. Access is restricted by law or regulation to particular groups of people with the necessary security clearance and need to know, ...

, Remington Rand management was unaware of this machine before this. The first commercially sold UNIVAC 1103 was sold to the

aircraft An aircraft is a vehicle that is able to flight, fly by gaining support from the Atmosphere of Earth, air. It counters the force of gravity by using either Buoyancy, static lift or by using the Lift (force), dynamic lift of an airfoil, or in ...

manufacturer

Convair Convair, previously Consolidated Vultee, was an American aircraft manufacturing company that later expanded into rockets and spacecraft. The company was formed in 1943 by the merger of Consolidated Aircraft and Vultee Aircraft. In 1953, i ...

, where Marvin Stein worked with it. Remington Rand announced the UNIVAC 1103 in February 1953. The machine competed with the

IBM 701 The IBM 701 Electronic Data Processing Machine, known as the Defense Calculator while in development, was IBM’s first commercial scientific computer and its first series production mainframe computer, which was announced to the public on May ...

in the scientific computation market. In early 1954, a committee of the

Joint Chiefs of Staff The Joint Chiefs of Staff (JCS) is the body of the most senior uniformed leaders within the United States Department of Defense, that advises the president of the United States, the secretary of defense, the Homeland Security Council and the ...

requested that the two machines be compared for the purpose of using them for a Joint Numerical Weather Prediction project. Based on the trials, the two machines had comparable computational speed, with a slight advantage for IBM's machine, but the latter was favored unanimously for its significantly faster input-output equipment. The successor machine was the UNIVAC 1103A or ''Univac Scientific'', which improved upon the design by replacing the unreliable

Williams tube The Williams tube, or the Williams–Kilburn tube named after inventors Freddie Williams and Tom Kilburn, is an early form of computer memory. It was the first random-access digital storage device, and was used successfully in several early co ...

memory with

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 magnet ...

, adding hardware

floating-point In computing, floating-point arithmetic (FP) is arithmetic that represents real numbers approximately, using an integer with a fixed precision, called the significand, scaled by an integer exponent of a fixed base. For example, 12.345 can ...

instructions, and perhaps the earliest occurrence of a hardware

interrupt In digital computers, an interrupt (sometimes referred to as a trap) is a request for the processor to ''interrupt'' currently executing code (when permitted), so that the event can be processed in a timely manner. If the request is accepted, ...

feature.

Technical details

The system used electrostatic storage, consisting of 36

s with a capacity of 1024 bits each, giving a total

random-access memory Random-access memory (RAM; ) is a form of computer memory that can be read and changed in any order, typically used to store working data and machine code. A random-access memory device allows data items to be read or written in almost the ...

of 1024

words A word is a basic element of language that carries an objective or practical 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 conse ...

of 36 bits each. Each of the 36 Williams tubes was five inches in diameter. A magnetic

drum memory Drum memory was a magnetic data storage device invented by Gustav Tauschek in 1932 in Austria. Drums were widely used in the 1950s and into the 1960s as computer memory. For many early computers, drum memory formed the main working memory of ...

provided 16,384 words. Both the electrostatic and drum memories were directly addressable: addresses 0 through 01777 (

Octal The octal numeral system, or oct for short, is the radix, base-8 number system, and uses the Numerical digit, digits 0 to 7. This is to say that 10octal represents eight and 100octal represents sixty-four. However, English, like most languages, ...

) were in electrostatic memory and 040000 through 077777 (

) were on the drum. Fixed-point numbers had a 1-bit sign and a 35-bit value, with negative values represented in

ones' complement The ones' complement of a binary number is the value obtained by inverting all the bits in the binary representation of the number (swapping 0s and 1s). The name "ones' complement" (''note this is possessive of the plural "ones", not of a sin ...

format. Instructions had a 6-bit operation code and two 15-bit operand addresses. Programming systems for the machine included the RECO regional coding assembler by Remington-Rand, the RAWOOP one-pass assembler and SNAP floating point interpretive system authored by the

Ramo-Wooldridge Corporation TRW Inc., was an American corporation involved in a variety of businesses, mainly aerospace, electronics, automotive, and credit reporting.http://www.fundinguniverse.com/company-histories/TRW-Inc-Company-History.html TRW Inc. It was a pioneer ...

Los Angeles Los Angeles ( ; es, Los Ángeles, link=no , ), often referred to by its initials L.A., is the largest city in the state of California and the second most populous city in the United States after New York City, as well as one of the world ...

, the FLIP floating point arithmetic interpretive system by Consolidated Vultee Aircraft of

San Diego San Diego ( , ; ) is a city on the Pacific Ocean coast of Southern California located immediately adjacent to the Mexico–United States border. With a 2020 population of 1,386,932, it is the eighth most populous city in the United States ...

, and the CHIP floating point interpretive system by

Wright Field Wilbur Wright Field was a military installation and an airfield used as a World War I pilot, mechanic, and armorer training facility and, under different designations, conducted United States Army Air Corps and Air Forces flight testing. Lo ...

Ohio Ohio () is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. Of the List of states and territories of the United States, fifty U.S. states, it is the List of U.S. states and territories by area, 34th-l ...

. UNIVAC 1103/A weighed about .

1103A

The UNIVAC 1103A or Univac Scientific was an upgraded version introduced in March 1956. Significant new features on the 1103A were its magnetic-core memory and the addition of

s to the processor. The UNIVAC 1103A had up to 12,288 words of 36-bit magnetic

core memory Core or cores may refer to: Science and technology * Core (anatomy), everything except the appendages * Core (manufacturing), used in casting and molding * Core (optical fiber), the signal-carrying portion of an optical fiber * Core, the centra ...

, in one to three banks of 4,096 words each. Fixed-point numbers had a one-bit sign and a 35-bit value, with negative values represented in

format.

Floating-point In computing, floating-point arithmetic (FP) is arithmetic that represents real numbers approximately, using an integer with a fixed precision, called the significand, scaled by an integer exponent of a fixed base. For example, 12.345 can ...

numbers had a one-bit sign, an eight-bit characteristic, and a 27-bit mantissa. Instructions had a six-bit operation code and two 15-bit operand addresses. The 1103A was contemporary with, and a competitor to, the

IBM 704 The IBM 704 is a large digital mainframe computer introduced by IBM in 1954. It was the first mass-produced computer with hardware for floating-point arithmetic. The IBM 704 ''Manual of operation'' states: The type 704 Electronic Data-Proce ...

, which also employed vacuum-tube logic, magnetic-core memory, and floating-point hardware. A version of this machine was sold to the Lewis Research Center, NACA (National Advisory Committee for Aeronautics) in Cleveland, Ohio. It had the first magnetic core of 1096 words of 36 bits. The magnetic drum storage had a capacity of 16,384 words, and the clock speed was 500KHz. Input/output was teletype paper tape. When NACA became NASA in 1958, a series of improvements was begun to improve functionality and reliability. Over the next ten years, the machine was significantly upgraded by replacing the magnetic core with a commercial solid state 16,384 word magnetic core system. An 8 unit magnetic tape system, a floating point arithmetic unit, and an indirect addressing unit were designed and built in-house. All solid-state commercial electronics modules were interfaced to the vacuum tube electronics in the original machine.

1104

The 1104 system was a 30- bit version of the 1103 built for

Westinghouse Electric The Westinghouse Electric Corporation was an American manufacturing company founded in 1886 by George Westinghouse. It was originally named "Westinghouse Electric & Manufacturing Company" and was renamed "Westinghouse Electric Corporation" in ...

in 1957, for use on the

BOMARC Missile Program The Boeing CIM-10 BOMARC (Boeing Michigan Aeronautical Research Center) (IM-99 Weapon System prior to September 1962) was a supersonic ramjet powered long-range surface-to-air missile (SAM) used during the Cold War for the air defense of North ...

. However, by the time the BOMARC was deployed in the 1960s, a more modern computer (a version of the

AN/USQ-20 The AN/USQ-20, or CP-642 or Naval Tactical Data System (NTDS), was designed as a more reliable replacement for the Seymour Cray-designed AN/USQ-17 with the same instruction set. The first batch of 17 computers were delivered to the Navy sta ...

, designated the G-40) had replaced the UNIVAC 1104.

Technical details

1103A

1104

See also

References

Further reading