Sperry Rand gained the rights to the ENIAC patent in 1956, and later sued other computer companies for copyright royalties. Sperry Rand first sued IBM for $2.5 million. It then filed a lawsuit against Honeywell in 1967, but Honeywell filed to countersue, and Honeywell's claim was granted first. The court case took place in federal court in Minneapolis, Minnesota, and began on June 1, 1971. While preparing for the case, the Honeywell lawyers discovered Dr. Atanasoff and the ABC. They used the ABC to dispute the fact that the ENIAC was the first computer. They brought Atanasoff in to testify; he stated that while building the ABC he was visited by John Mauchly, who took extensive notes on the ABC. This testimony was then used by the Honeywell lawyers to show that Mauchly had taken elements of the ABC and used them in the ENIAC. Mauchly testified that he did not remember much about the event and omitted many details; making Atanasoff's testimony all the more believable. On October 19, 1973, Judge Earl R. Larson ruled in favor of Honeywell. Despite the influence of the case it is relatively unknown because it was drastically overshadowed in the news by the Watergate Scandal. Even though the ABC is the first the ENIAC still was much more powerful than the ABC and helped propel the computer industry.
John Atanasoff Jr. talking about his visit to Judge Larson.