There were two main criticisms of the work: mathematicians criticized the use of primitive integration methods in their calculations of the trajectories of ordnance devices, and the engineers predicted that the low reliability of the vacuum tubes would undermine the project.
Eckert countered the mathematical objections by pointing out that the intervals were much less than had been used in hand calculations. In any case the flexibility of the system, as a result of the ability to "program" the calculator, permitted the use of more sophisticated methods.
There was some concern regarding the cumulative effect of round-off or truncation errors, but this too was overcome. These problems were primarily solved by John Mauchly, who concentrated on the "software" and "programming" problems, while Eckert dealt with the hardware problems, including the tube reliability difficulty.
The primary problem that Eckert and Mauchly encountered in this project was the need to use a large number of vacuum tubes eventually over 18, , which were notoriously unreliable. Fermi's prediction was off by two orders of magnitude. They provided much useful advice on this problem--mainly to keep the heaters of the tubes under power, rather than turning them on and off continually.
They also received help from the International Resistance Company, of which Brainerd was a primary stockholder, for the supply of reliable, accurate resistors. Once the first two panels of the ENIAC had been completed, Eckert was convinced of the team's ability to complete the machine. The telltale lamps, which they had installed to indicate the operation of the panels, intrigued everyone on the project; Eckert believed that this innovation was the basis for the inclusion of flashing lights in every science fiction film thereafter.
Besides the development of the first general-purpose calculator, there were two major contributions which were not part of prior conceptions of calculators--hierarchical memory and "subroutines. Rather than a single cheap and fast memory, they developed a hierarchy of memories, some cheap and some fast. The concept of subroutines was derived from the need to repeat groups of instructions iteratively, and the need to re-use clusters of instructions.
Since the ENIAC was not a stored-program machine, subprograms could be stored on cards and tapes, but the concept was extended in later machines. In a dispute broke out at the university when Dean Brainerd asked the ENIAC project participants to sign documents which would assign their intellectual property rights to the university.
Rather than agree to give up their rights, Eckert and Mauchly chose to found the Electronic Control Corporation, which was renamed the Eckert-Mauchly Computer Corporation in While the EDVAC Electronic Discrete Variable Computer was still a dream at the university, Eckert and Mauchly had the concept of a commercial system, but with limited financial backing they needed a contract in order to provide the funding for further developments. This small machine never operated effectively after delivery to Northrop, but instead of persevering, Northrop allowed it to grow dusty in a corner.
The Univac machine was completed and worked successfully for several clients, although not to the profit of the company.
In the meantime the corporation was bought out by Remington-Rand, and Eckert was appointed as the director of engineering, Eckert-Mauchly Division, Remington-Rand Corporation in The line of machines created by Eckert and Mauchly was continued through a sequence of reorganizations with Eckert serving successively as vice president and director of Commercial Engineering, Remington-Rand Corporation , vice president and executive assistant to the general manager, Remington-Rand Corporation , and vice president and technical adviser to the president, Univac Division, Sperry-Rand Corporation Eckert retired the same year as the Univac name was finally dropped from the product line of the company.
In the s, Eckert was unfortunate to find himself put on the sidelines by counterclaims to the technology which he and Mauchly developed. During the final stages of the construction of the ENIAC, John von Neumann was inserted into the environment as a consultant and mentor and perhaps possible user.
Eckert and Mauchly had already recognized in , at a time when their project was still classified that the hierarchy of memory, in which different memories were associated with different elements of the "program " -- data, constants, functions, instructions -- was unnecessary. A homogeneous memory would allow for interchangeability -- a conclusion which implied the insertion of instructions into a modifiable, internal memory.
Corrected and reprinted in Ann. The report is clearly entitled "Draft" and there is a belief that the final copy would have had the names of other contributors.
However, this report is the primary source of the concept of the stored program, sometimes named the "von Neumann concept. It had a memory of words capacity and this was later improved to words.
The computer was made with components that included a control unit with an oscilloscope and a magnetic tape reader-recorder. It also had a dispatcher unit that received the instructions from the memory and control unit and directed them to other units.
The arithmetic operations were performed by a computational unit which sent the results to the memory after verification by another unit.
It occupied square feet of floor area and weighed 17, lbs. You must be logged in to post a comment. Skip to content Questions and Answers. Contact Page Privacy Policy. Previous article How to reduce your appetite? Next article How to get rid of fleas?
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