Who invented the computer?

This is not a question with a simple answer. It partly depends on what you mean by "computer". Many inventors contributed to the history of computers and that a computer is a complex piece of machinery made up of many parts, each of which can be considered a separate invention. Many say the first computer is the "difference engine." The first of these devices was conceived in 1786 by J.H. Müller. It was never built.

Difference engines were forgotten and then rediscovered in 1822 by Englishman Charles Babbage, who is known as "the father of the Computer". This machine used the decimal numbers system and was powered by cranking a handle. The British government first financed the project but then later cut off support. Babbage went on to design his much more general analytical engine but later returned and produced an improved design (his "Difference Engine No. 2") between 1834 and 1869. But he was never able to build any of these designs.

Others point out that this is the first DIGITAL computer. The earliest computer known is the Antikythera Machine, a mechanical analog device that computed the positions of the astrological signs on any given date, past or future. It was discovered in an ancient shipwreck in the Mediterranean Sea and dates to approximately 250 BC. The designer/builder is not known, but because of its similarity to other mechanical devices known to have been designed by Archimedes, it is probably his work.

Still others will say the abacus is the first computer. They were invented by the Chinese between 2600 BC and 300 BC is considered as the first computer ever. Abacus was used by the merchants and Clerks in China. However the abacus is NOT automatic, but it is digital; so it is more of a "calculation aid" or "calculator" than a computer.

Here is still more input:

  • If you mean Electronic Computer, it was a man called Alan Turing from Cambridge UK, who was drafted in to Bletchley park secret base where they worked at cracking the WWII enigma codes that the Germans used every day. The Germans changed their Enigma machines to a four digit code maker. However, Because what went on at Bletchley Park the computer made from thousands of valves was kept top secret up until recently. The computer, named Colossus was smashed to pieces at the end of the war. The buildings have now been restored as a tourist center.
  • The Colossus Mark I 1943, the world's first programmable, digital, electronic, computing devices... its follow up the Mark II was used by British codebreakers to read encrypted German "tunny" teletype cypher during World War II (notably D Day)
  • The first computer, or "modern computer" was invented in World War II by a German engineer, Konrad Zuse in 1941 called the Z3. The Z3 was a fully digital, binary, floating point arithmetic, electromechanical relay machine programmed with punch recycled 35mm film. About the only things it lacked were conditional branches, loops, and subroutines. It was destroyed in an allied bombing raid after completion but before it saw real use.
  • It was Konrad Zuse. He invented the z1, z2, z3, z4 and other ones. The z3 was the first fully functional program-controlled electromechanical digital computer in the world-completed in 1941. Charles Babbage just made a mechanical computing machine.
  • The first electronic digital computer was invented by Bulgarian John Vincent Atanasoff. He named it the Atanasoff Berry Computer, or the ABC. It was the world's first electronic digital computer and built between 1937-42 by John Vincent Atanasoff and Clifford Berry at Iowa State University. It used regenerative memory (i.e. dynamic), parallel processing, binary arithmetic and split computing functions (routines) away from memory use and management. However it was not programmable (it could only solve simultaneous equations problems).
  • Now, if we're talking technical knowledge and actual precursors to the PC - IBM may have accidentally spread it around when they allowed cloning of the PC architecture. But they were not the first. [This answer refers to desktop "personal" computers. These were far from the first computers.
  • These are all pre-IBM machines: MITS ALTAIR 8800, Apple II, TRS80, Atari 800 and the Commodore 64. [This answer refers to desktop "personal" computers. These were far from the first computers.
  • Purists who claim that the ALTAIR was not the first, will say it was 'Simon' by Berkley Enterprises, 1950, costing $300. [This answer refers to desktop "personal" computers. These were far from the first computers.]
  • The first completely electronic computer was developed in England in 1943. It was known as Colossus. It took up 1,000 Sq. ft. weighed 30 tons/60,000 pounds. And took 150 kilowatts which is enough power to light up a small town.
  • The first working computer (in the modern sense) was invented by Konrad Zuse. But others had created machines or ideas close to it before. These were people like Pascal, Leibniz and Turing.
  • The first patent for a working computer (outside the military) was the UNIVAC, created by Drs. John Mauchly and Presper Eckert in 1948. They formed the Eckert-Mauchly Computer Corporation, which was bought in 1950 (just as they were on the verge of bankruptcy) by Remington Rand. Their computer was used in the 1950 census (starting in mid-1951 when the first one was finished) and by Walter Cronkite in the 1952 Presidential election.
  • The ENIAC patent was declared invalid on October 19, 1973, by US Federal Judge Earl R. Larson. He attributed Atanasoff and Berry with the invention of the electronic digital computer. For more information see the related Link.
  • If you define a computer as the first device for doing mathematical calculations, the answer would be the "Babbage Difference Engine", invented by Charles Babbage but never completely built. However, computers trace their lineage to 19th-century power looms which became "programmable" by use of something akin to a punch-card which was used to determine which color thread would be used at any given time in the loom's weaving process. On an even more basic level, you could consider the first use of cams to determine timing of any mechanism (such as steam engine poppet valves) to be the first "computer".

Charles Babbage, an English mathematician, originated the concept of a programmable computer. Considered a "father of the computer", Babbage is credited with inventing the first mechanical computer that eventually led to more complex designs. His proposed models were the Difference Engine and the Analytical Engine. The Difference Engine came first around 1822 and was more limited and not programmable. it was intended to generate mathematical tables. This machine contained 25,000 parts and weighed 15 tons. Babbage followed this with a "difference engine 2" which, although well funded, was never completed. Babbage also designed a printer to go along with the computer, but this also was never completed. In 1989-1991, the London science museum made a difference engine 2 and printer from Babbage's design. Both worked perfectly. The programmer for the Analytical Engine, built around 1825, was Ada Lovelace (first programmer). None of these machines was ever built during Babbage's time, for many reasons including: Babbage could never finalize a design he always had to go on to improved designs, arguments with his machinist, funding, etc.

American physicist John Atanasoff built the first rudimentary electronic computer in the late 1930s and early 1940s, although for several decades afterward credit for the first electronic computer went to the scientists who assembled the Electronic Numerical Integrator and Computer (ENIAC) for the United States military by 1945. Danish physicist Allan Mackintosh recounts in a Scientific American article how Atanasoff first conceived of the design principles that are still used in present-day computers. Dr. Atanasoff's Computer The men who for decades were credited with inventing the first electronic digital computers were not, in fact, first. That honor belongs to a once forgotten physicist named John V. Atanasoff.