Chronology of Calculator and Computer Technology

1617 John Napier discusses the Napier's bones calculating method in Rabdologia.
1622 William Oughtred invents the slide rule.
1623 Wilhelm Schickard builds his 6-digit "Calculating Clock'' that can add and subtract.
1645 Blaise Pascal completes his 5-digit "Pascaline'' that can add.
1930 Vannevar Bush builds a partly electronic computer capable of solving differential equations.
1946 Presper Eckert and John Mauchly announce ENIAC, the first practical entirely electronic computer.
1948 William Shockley, Walter Brattain, and John Bardeen invent the transistor.
1950 Alan Turing proposes the "Turing test'' criterion for an intelligent machine.
1951 Presper Eckert and John Mauchly finish UNIVAC I, the first mass-produced electronic computer.
1971 Texas Instruments releases the first easily portable electronic calculator.
1977 Apple Computer releases the Apple II personal computer.