Physicist John Atanasoff invented the world's first electronic digital computer, the Atanasoff-Berry Computer, between 1937 and 1942.

The Atanasoff-Berry Computer (ABC) was developed at Iowa State College, now Iowa State University, between 1937 and 1942. John Vincent Atanasoff conceived the design during a pivotal late-night drive to Illinois in 1937, where he outlined four critical principles for modern computing: using electronics instead of mechanical switches, employing binary arithmetic rather than the decimal system, using capacitors for memory, and performing calculations using electronic switching rather than mechanical motion.The machine utilized approximately 300 vacuum tubes to perform calculations and featured a regenerative capacitor memory system—a direct precursor to the DRAM found in modern devices today. Unlike earlier mechanical calculators, the ABC could solve systems of up to 29 linear equations simultaneously, representing a massive leap in computational power for its era.Despite its ingenuity, the ABC was not programmable and remained a special-purpose machine designed for a specific task. Its place in history was formally secured in 1973 following the landmark legal case Honeywell v. Sperry Rand. U.S. District Judge Earl R. Larson voided the ENIAC patent, officially recognizing Atanasoff as the true inventor of the electronic digital computer and crediting him over J. Presper Eckert and John Mauchly, who had previously received credit for developing the ENIAC.