Commissioned in 1943, partially functional in July 1944, but not entirely finished until Feb. 1, 1946, ENIAC is the first all-electronic general-purpose Turning complete computer.
Engineers built ENIAC to calculate ordinance tables. Eventually, von Neumann used the computer to perform calculations for nuclear weapons and break ENIGMA encrypted messages. Built at the University of Pennsylvania, ENIAC was a WWII military project.
Markedly, all ENIAC programmers were women. Evidently, most programmers had prior experience computing ballistic tables by hand. Programming ENIAC required literally rewriting the computer by changing switches and cables for each different program.
As with countless computer projects that followed, ENIAC had an initial budget of $61,700. Eventually, the final budget was $500,000, about 8x over-budget.
Patent Lawsuit: Honeywell v. Sperry Rand
Significantly, a predecessor of the ENIAC is the Atanasoff-Berry computer, tested in 1942. Neither fully mechanical nor electrical, it was somewhere between the Z3 and the ENIAC. Cited in the epic lawsuit Honeywell v. Sperry Rand (1973) as prior art, the computer was cited as prior art to invalidate virtually all computer patents.
Honeywell was the longest federal court case in history, with 135 days of testimony. Basically, the case establishes both that John Atanasoff is the innovator of the modern computer and that patent rights for the ENIAC were unenforceable and invalid due to patent filing issues. Additionally, the case is also a good illustration of patent abuse, collusion, and misuse of public works that remained a thread, especially in the computer industry.