| There are many earlier computers than ENIAC. ENIAC has been claimed to be only the first electronic computer, i.e. made with vacuum tubes instead of relays or other electromechanical devices, which decreased the switching times from milliseconds to microseconds. Some earlier electromechanical computers, including those of Zuse and those of Aiken, had structures much closer to a modern computer than ENIAC, except that they used distinct kinds of memories for the program and for the data. The name "Harvard architecture" for the computers with separate program and data memories comes from the electromechanical computers of Aiken, who worked at Harvard. While ENIAC can be considered the first really useful electronic computer, it has been preceded by another more special-purpose electronic computer, that of John Atanasoff, which had a structure dedicated to solving systems of algebraic equations. Moreover, the development of the Atanasoff computer and of the ENIAC computer (both in USA) has been made possible by the previous invention of various kinds of electronic counters, made with vacuum tubes or gas tubes, which had been invented by several physicists who had worked in UK in the research of nuclear and cosmic radiation, during the decade preceding WWII. The priority of the Atanasoff computer was used to invalidate the patents related to ENIAC, as a result of the Honeywell vs. Sperry Rand lawsuit. The conclusion of the lawsuit was deserved by the ENIAC team, because one of them had visited Atanasoff, gaining useful intel about how to design the electronic circuits of the future ENIAC, but then in multiple occasions they have attempted to present their work as more original than it really was, omitting any references to their prior sources of inspiration. ENIAC received a big budget due to the war, which resulted in a machine very big and very fast for those times, which has been used to solve a great number of important mathematical problems. Nevertheless, in the few documents that have remained from the Atanasoff-Berry university project, Atanasoff demonstrated a much clearer understanding of the problems of automatic computing than the ENIAC team, like also von Neumann would demonstrate later. An important contribution of the Atanasoff computer was the invention of the dynamic memory, which was made with discrete capacitors, but it was nonetheless the ancestor of the current DRAM memories. The inadequate memory capacity was the greatest disadvantage of ENIAC, which was immediately noticed by von Neumann. It was very fortunate that von Neumann had the opportunity to study the ENIAC project, because he had the vision of the future that the ENIAC team lacked. The ENIAC team has been obsessed more with how to monetize their experience in the ENIAC project than about how to improve their computer and they were annoyed that von Neumann has explained publicly to anyone how to make better electronic computers, which has started a great number of projects for developing electronic computers, not only in USA, but also in many other countries. |