Who invented CPU?

Answer 1

John Vincent Atanasoff developed the ABC (Atanasoff-Berry Computer) at Iowa State University in October 1939 as in the following link.

Patent dispute details: J. Presper Eckert and John Mauchly were the first to patent a digital computing device, the ENIAC. The ABC had been examined by John Mauchly in June 1941, and Isaac Auerbach,[6] a former student of Mauchly's, alleged that it influenced his later work on ENIAC, although Mauchly denied this (Shurkin, pg. 280-299). In 1967 Honeywell sued Sperry Rand in an attempt to break their ENIAC patents, arguing the ABC constituted prior art. The United States District Court for the District of Minnesota released its judgement on October 19, 1973, finding in Honeywell v. Sperry Rand that the ENIAC patent was a derivative of John Atanasoff's invention. The decision was not appealed.

Campbell-Kelly and Aspray conclude:

The extent to which Mauchly drew on Atanasoff's ideas remains unknown, and the evidence is massive and conflicting. The ABC was quite modest technology, and it was not fully implemented. At the very least we can infer that Mauchly saw the potential significance of the ABC and that this may have led him to propose a similar, electronic solution.

The case was legally resolved on October 19, 1973 when U.S. District Judge Earl R. Larson held the ENIAC patent invalid, ruling that the ENIAC derived many basic ideas from the Atanasoff-Berry Computer. Judge Larson explicitly stated, "Eckert and Mauchly did not themselves first invent the automatic electronic digital computer, but instead derived that subject matter from one Dr. John Vincent Atanasoff".