3000 BC
The Abacus is invented in Babylonia.

500 BC
Egyptians use a system of beads and wires for counting.

1617
John Napier Demonstrates his Napier Bones for multiplication and division.

1622
The Slide Rule is invented in England.

1624
The first four-function calculator is built by Wilhelm Schickard.

1642
Blaise Pascal builds the first numerical calculating machine.

1673
Gottfried Liebniz builds a four-function mechanical machine.

1805
Joseph-Marie Jacquard uses punched card for his looming process, therefore creating the first program.

1822
Charles Babbage creates a Difference Engine to calculate logarithms.

1833
Babbage creates an analytical machine with instructions from punched cards, thus creating the first programmable computer.

1842
Ada Lovelace writes programs for Babbage's Machine.

1882
The first commercially-successful mechanical adding machine is created by William Burroughs.

1890
Herman Hollerith develops a punched-card machine for use in the US Census.

1890
Hollerith founds the Tabulating Machine Company, later called Computing-Tabulating-Recording Company.

1924
Computing-Tabulating-Recording Company changes its name to International Business Machines, IBM.

1925
Vannevar Bush builds the differential analyzer, a large scale analog calculator.

1931
Konrad Zuse builds the first calculator, the Z1.

1937
The first binary calculator is built by George Stibitz at Bell Labs.

1939
John Atanasoff designs the ABC Computer. In 1973 a judge ruled it the first automatic digital computer.

1941
The Colossus computer is built by Alan Turing.

1944
The Colossus Mark II is built in England.

1945
John Von Neumann designs the EDVAC, the first stored-program computer.

1946
The BINAC is designed. It is the first computer to work in real-time.

1946
The ENIAC is built. It is the largest and most powerful computer of its time, consisting of 18,000 vacuum tubes. It weighted 80 tons and could do 5,000 additions and 360 multiplications per second.

1946
The UNIVAC is built.