BINAC (Binary Automatic Computer) was an early electronic

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

designed for

Northrop Aircraft Company Northrop Grumman Corporation is an American multinational aerospace and defense technology company. With 90,000 employees and an annual revenue in excess of $30 billion, it is one of the world's largest weapons manufacturers and military techn ...

by the

Eckert–Mauchly Computer Corporation The Eckert–Mauchly Computer Corporation (EMCC) (March 1946 – 1950) was founded by J. Presper Eckert and John Mauchly. It was incorporated on December 22, 1947. After building the ENIAC at the University of Pennsylvania, Eckert and ...

(EMCC) in 1949. Eckert and Mauchly, though they had started the design of EDVAC at the

University of Pennsylvania The University of Pennsylvania (also known as Penn or UPenn) is a private research university in Philadelphia. It is the fourth-oldest institution of higher education in the United States and is ranked among the highest-regarded universitie ...

, chose to leave and start EMCC, the first computer company. BINAC was their first product, the first

stored-program computer A stored-program computer is a computer that stores program instructions in electronically or optically accessible memory. This contrasts with systems that stored the program instructions with plugboards or similar mechanisms. The definition i ...

in the United States; BINAC is also sometimes claimed to be the world's first commercial digital computer even though it was limited in scope and never fully functional after delivery.

Architecture

The BINAC was a bit-serial

binary Binary may refer to: Science and technology Mathematics * Binary number, a representation of numbers using only two digits (0 and 1) * Binary function, a function that takes two arguments * Binary operation, a mathematical operation that t ...

computer with two independent CPUs, each with its own 512-

word A word is a basic element of language that carries an semantics, objective or pragmatics, practical semantics, meaning, can be used on its own, and is uninterruptible. Despite the fact that language speakers often have an intuitive grasp of w ...

acoustic mercury delay-line

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, ...

. The CPUs continuously compared results to check for errors caused by hardware failures. It used approximately 700

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 voltage, potential difference has been applied. The type kn ...

s. The 512-word acoustic mercury delay-line memories were divided into 16 channels, each holding 32 words of 31

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, with an additional 11-bit space between words to allow for circuit delays in switching. The clock rate was 4.25 MHz (1 MHz according to one source), which yielded a word access time of about 10

microsecond 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 n ...

s. The addition time was 800 microseconds, and the multiplication time was 1200 microseconds. Programs or data were entered manually in

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, ...

using an eight-key keypad or were loaded from magnetic tape. BINAC was significant for being able to perform high-speed arithmetic on binary numbers, with no provisions to store characters or

decimal The decimal numeral system (also called the base-ten positional numeral system and denary or decanary) is the standard system for denoting integer and non-integer numbers. It is the extension to non-integer numbers of the Hindu–Arabic numeral ...

digits.

Early test programs

The BINAC ran a test program (consisting of 23 instructions) in March 1949, although it was not fully functional at the time. Here are early test programs that BINAC ran: * February 7, 1949 – Ran a five-line program to fill the memory from register A. * February 10, 1949 – Ran a five-line program to check memory. * February 16, 1949 – Ran a six-line program to fill memory. * March 7, 1949 – Ran 217 iterations of a 23-line program to compute squares. It was still running correctly when it stopped. * April 4, 1949 – Ran a fifty-line program to fill memory and check all instructions. It ran for 2.5 hours before encountering an error. Shortly after that it ran for 31.5 hours without error.

Customer acceptance

Northrop accepted delivery of BINAC in September 1949. Northrop employees said that BINAC never worked properly after it was delivered, although it had worked at the Eckert-Mauchly workshop. It was able to run some small programs but did not work well enough to be used as a production machine. Northrop attributed the failures to it not being properly packed for shipping when Northrop picked it up; EMCC said that the problems were due to errors in re-assembly of the machine after shipping. Northrop, citing security considerations, refused to allow EMCC technicians near the machine after shipping, instead hiring a newly graduated engineering student to re-assemble it. EMCC said that the fact that it worked at all after this was testimony to the engineering quality of the machine.

First computer user manual

Previous computers were the darlings of university departments of engineering; the users knew the machines well. The BINAC was going to go to an end user, and so a ''user'' manual was needed. Automobile "users" were quite accustomed in those days to doing significant servicing of their vehicles, and "user manuals" existed to help them. The BINAC manual writers took inspiration from those manuals when writing the user manual for the BINAC.

References

External links

Oral history interview with Isaac Levin Auerbach
Oral history interview by Nancy B. Stern, 10 April 1978.

Charles Babbage Institute The IT History Society (ITHS) is an organization that supports the history and scholarship of information technology by encouraging, fostering, and facilitating archival and historical research. Formerly known as the Charles Babbage Foundation, ...

, University of Minnesota, Minneapolis. Auerbach recounts his experiences at Electronic Control Company (later the Eckert-Mauchly Computer Company) during 1947–1949. He emphasizes the economic and practical infeasibility of the BINAC computer project for

Northrop Aircraft Northrop Corporation was an American aircraft manufacturer from its formation in 1939 until its 1994 merger with Grumman to form Northrop Grumman. The company is known for its development of the flying wing design, most successfully the B-2 Spiri ...

. Auerbach also discusses the

UNIVAC UNIVAC (Universal Automatic Computer) was a line of electronic digital stored-program computers starting with the products of the Eckert–Mauchly Computer Corporation. Later the name was applied to a division of the Remington Rand company an ...

, including personalities, politics, and its technical features. The roles of the

National Bureau of Standards The National Institute of Standards and Technology (NIST) is an agency of the United States Department of Commerce whose mission is to promote American innovation and industrial competitiveness. NIST's activities are organized into physical sci ...

Raytheon Raytheon Technologies Corporation is an American multinational aerospace and defense conglomerate headquartered in Arlington, Virginia. It is one of the largest aerospace and defense manufacturers in the world by revenue and market capitaliza ...

Remington Rand Remington Rand was an early American business machine manufacturer, originally a typewriter manufacturer and in a later incarnation the manufacturer of the UNIVAC line of mainframe computers. Formed in 1927 following a merger, Remington Rand wa ...

, and IBM. *
Roger Mills' Description of the BINAC

Picture of BINAC history sign in Northeast Philadelphia

YouTube: Video History of BINAC
{{Mainframes Vacuum tube computers One-of-a-kind computers 1940s computers Computer-related introductions in 1949 Serial computers