Before leaving for Iowa, Mauchly had applied for a special six-week summer course at the University of Pennsylvania. With war on the horizon, the army was sponsoring special defense training classes at universities around the country, seeking to recruit engineers, teachers, and other people for managerial positions in the military and industry. The program, with its emphasis on electronics, was ideal for Mauchly, who had been hoping to leave Ursinus for a higher-paying job in industry; unfortunately, he lacked sufficient skill in electronics to attract any offers. He was accepted into the program and did quite well – well enough for the Moore School to offer him a job as an instructor.
Meanwhile, Mauchly continued to correspond with Atanasoff. On 30 September 1941 – about a year before he composed the ENIAC memo – he wrote his friend:
As time goes on, I expect to get a first-hand knowledge of the operation of the differential analyzer – I have already spent a bit of time watching the process of setting up and operating the thing – and with this background I hope I can outdo the analyzer electronically.
A number of different ideas have come to me anent computing circuits – some of which are more or less hybrids, combining your methods with other things, and some of which are nothing like your machine. The question in my mind is this: Is there any objection, from your point of view, to my building some sort of computer which incorporates some of the features of your machine? For the time being, of course, I shall be lucky to find time and material to do more than merely make exploratory tests of some of my different ideas, with the hope of getting something very speedy, not too costly, etc.
Ultimately, a second question might come up, of course, and that is, in the event that your present design were to hold the field against all challengers, and I got the Moore School interested in having something of the sort, would the way be open for us to build an “Atanasoff Calculator” (a la Bush analyzer) here?
In reply, Atanasoff asked Mauchly to keep his work confidential until his attorney had filed a patent application. He and Iowa State had agreed to share the expense of patenting the invention and to split any profits, with a small percentage going to Berry. Atanasoff had hired a Chicago patent attorney, Richard R. Trexler, and had sent him the necessary technical information.
In another letter, Mauchly invited Atanasoff to stay with him during his next trip to the East Coast. But war broke out that December – the Japanese attacked Pearl Harbor – and Atanasoff and Berry went winging off in different directions. Berry married Atanasoff’s secretary and joined an engineering firm in California that July. Two months later, Atanasoff went to work for the Naval Ordnance Laboratory in Maryland and was put in charge of an underwater mine-testing program. Incredibly, Trexler, who had not considered Atanasoff’s information adequate, even though Atanasoff and Berry had showered him with material, never applied for a patent. Neither he nor Iowa State, which neglected to give him the permission to proceed, grasped the significance of Atanasoff’s work. In fact, even Atanasoff himself failed to understand the importance of his invention and, caught up in the war, eventually let the matter drop. As for the ABC? It was disassembled in 1948.
But Atanasoff’s work lived on through Mauchly. As a student at the Moore School, Mauchly became friends with J. Presper Eckert, Jr., then a graduate student in charge of the student laboratories. In his early twenties, Eckert was a gifted electronics engineer, and by all accounts the Moore School’s best. He was a born engineer; as a teenager at Penn Charter Academy, a prestigious private school outside Philadelphia, Eckert had built a powerful sound system with advanced features that didn’t show up in commercial amplifiers until years later. He was a brash, confident, no-nonsense young man who had graduated near the top of his class at the Moore School in 1941 and who had won a two-year fellowship to study for his master’s.
Mauchly spent many hours with Eckert discussing his ideas on computing – ideas that centered on the construction of a high-speed electronic calculator. Eckert, who was familiar with the differential analyzer and who was involved in several military and industrial projects, readily grasped the need for a high-speed calculator and saw no technical barrier to its construction. Mauchly also told him about Atanasoff’s work, and Eckert suggested changes and improvements in Atanasoff’s design, recommending, for instance, that the memory be built out of tubes instead of condensers, which would, in a large high-speed machine, require a lot of supporting equipment. As a result of these discussions and his knowledge of Atanasoff’s achievements, Mauchly was inspired to write the memo that led to ENIAC.