The BINAC. A product of the Eckert-Mauchly Computer Corp.

N.P. Eckert-Mauchly Computer Corp. 1949.

Rare sales brochure for Eckert and Mauchly’s BINAC, the first operational stored-program computer in the United States.

❧Origins of Cyberspace 1145.

J. Presper Eckert, together with his partner John Mauchly, invented and constructed the first general-purpose digital computer (the ENIAC) during World War II. After the war he and Mauchly founded the first commercial computer company in the United States, the Electronic Control Co., soon renamed the Eckert-Mauchly Computer Corporation. While developing the UNIVAC for the U. S. Census Bureau, Eckert and Mauchly contracted with the Northrop Aircraft Company in southern California to develop and construct a BINary Automatic Computer (BINAC). The contract was signed in October 1947, with Northrop providing $80,000 up front; another $20,000 was due upon delivery of the machine. “Had it been finished on time [i.e., by May 15, 1948] it would have been in contention with the British computers at Manchester and Cambridge as the first working electronic stored-program computer. In reality it ran its first program in the late summer of 1949 and, as a consequence, became the first operational computer in America but not in the world” (Williams, pp. 361–2). With both input and output in base 8 (a compact way of representing binary values), the BINAC’s design made it very difficult to use; in addition BINAC’s complex and delicate machinery suffered in the delivery from Philadelphia to California, so much so that it was never able to function effectively as a production machine. Only one BINAC was ever made.

“The BIN in BINAC stood for “binary” and this was significant in at least two respects. First, the design called for a serial machine which would be capable of performing high-speed arithmetic on binary numbers with no provision to store characters or decimal digits. Secondly, BINAC was really two machines in one; every part of the machine was constructed as a pair of systems to check each operation. Any instruction would be executed once by each unit, the result compared between the units and, if identical, the next instruction in sequence would be initiated. If any discrepancy was found between the two halves of the machine, it halted.

“Besides the innovative approach of using two parallel machines to check each other and the one large tank design of the mercury delay-lines [which provided the machine’s memory], the BINAC was the first to employ magnetic tape as a secondary memory and auxiliary input device” (ibid. p. 362).

Published the year BINAC was delivered, the flyer contains the computer’s statistics, a brief outline of its elements and general characteristics, coding instructions, and a conversion table comparing decimal, coded decimal, binary, and octal numbers. A full-page illustration shows the various components of the system. The document was likely produced for distribution when the machine was being demonstrated to interested parties. It may be the only document extant that gives the complete instruction set (sixteen instructions) for BINAC. Few copies of this brochure would have been distributed, as only one machine was sold, and Eckert-Mauchly rapidly turned their attention to building UNIVAC.

Williams, A History of Computing Technology, 1985.

Reproduced typescript, stapled, 8 sheets, including full page illustration. Very fine condition, scarce.

Item #3320

Price: $4,500.00

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