Short for Atanasoff-Berry Computer, the ABC started being developed by Professor John Vincent Atanasoff and graduate student Cliff Berry in 1937 and continued to be developed until 1942 at the Iowa State College (now Iowa State University). On October 19, 1973, US Federal Judge Earl R. Larson signed his decision that the ENIAC patent by Eckert and Mauchly was invalid and named Atanasoff the inventor of the electronic digital computer.
The ENIAC was invented by J. Presper Eckert and John Mauchly at the University of Pennsylvania and began construction in 1943 and was not completed until 1946. It occupied about 1,800 square feet and used about 18,000 vacuum tubes, weighing almost 50 tons. Although the Judge ruled that the ABC computer was the first digital computer many still consider the ENIAC to be the first digital computer.
ENIAC short for Electronic Numerical Integrator And Computer, was the first,general-purpose electronic computer. It was a Turing-complete digital computer capable of being reprogrammed to solve a full range of computing problems.

ENIAC was designed to calculate artillery firing tables for the United States Army's Ballistic Research Laboratory.When ENIAC was announced in 1946 it was heralded in the press as a "Giant Brain". It boasted speeds one thousand times faster than electro-mechanical machines, a leap in computing power that no single machine has since matched. This mathematical power, coupled with general-purpose programmability, excited scientists and industrialists. The inventors promoted the spread of these new ideas by teaching a series of lectures on computer architecture.
The ENIAC's design and construction was financed by the United States Army during World War II. The construction contract was signed on June 5, 1943, and work on the computer began in secret by the University of Pennsylvania's Moore School of Electrical Engineering starting the following month under the code name "Project PX". The completed machine was announced to the public the evening of February 14, 1946 and formally dedicated the next day at the University of Pennsylvania, having cost almost $500,000 (nearly $6 million in 2010, adjusted for inflation). It was formally accepted by the U.S. Army Ordnance Corps in July 1946. ENIAC was shut down on November 9, 1946 for a refurbishment and a memory upgrade, and was transferred to Aberdeen Proving Ground, Maryland in 1947. There, on July 29, 1947, it was turned on and was in continuous operation until 11:45 p.m. on October 2, 1955.
Because of the Judge ruling and because the case was never appealed like most we consider the ABC to be the first digital computer. However, because the ABC was never fully functional we consider the first functional digital computer to be the ENIAC.
The ENIAC was invented by J. Presper Eckert and John Mauchly at the University of Pennsylvania and began construction in 1943 and was not completed until 1946. It occupied about 1,800 square feet and used about 18,000 vacuum tubes, weighing almost 50 tons. Although the Judge ruled that the ABC computer was the first digital computer many still consider the ENIAC to be the first digital computer.
ENIAC short for Electronic Numerical Integrator And Computer, was the first,general-purpose electronic computer. It was a Turing-complete digital computer capable of being reprogrammed to solve a full range of computing problems.

ENIAC was designed to calculate artillery firing tables for the United States Army's Ballistic Research Laboratory.When ENIAC was announced in 1946 it was heralded in the press as a "Giant Brain". It boasted speeds one thousand times faster than electro-mechanical machines, a leap in computing power that no single machine has since matched. This mathematical power, coupled with general-purpose programmability, excited scientists and industrialists. The inventors promoted the spread of these new ideas by teaching a series of lectures on computer architecture.
The ENIAC's design and construction was financed by the United States Army during World War II. The construction contract was signed on June 5, 1943, and work on the computer began in secret by the University of Pennsylvania's Moore School of Electrical Engineering starting the following month under the code name "Project PX". The completed machine was announced to the public the evening of February 14, 1946 and formally dedicated the next day at the University of Pennsylvania, having cost almost $500,000 (nearly $6 million in 2010, adjusted for inflation). It was formally accepted by the U.S. Army Ordnance Corps in July 1946. ENIAC was shut down on November 9, 1946 for a refurbishment and a memory upgrade, and was transferred to Aberdeen Proving Ground, Maryland in 1947. There, on July 29, 1947, it was turned on and was in continuous operation until 11:45 p.m. on October 2, 1955.
Because of the Judge ruling and because the case was never appealed like most we consider the ABC to be the first digital computer. However, because the ABC was never fully functional we consider the first functional digital computer to be the ENIAC.
