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Pascaline Calaculator is Invented
-Invented in 1642 by the French philosopher and mathematician Blaise Pascal.
-It was a complicated set of gears that operated similarly to a clock.
-It was designed to only perform addition.
-Due to manufacturing problems, it never worked work properly. -
Stepped Reckoner is Completed
-Gottfried Wilhelm von Leibniz, invented the stepped reckoner
-supposed to be able to add, subtract, multiply, divide, and square roots.
-Included a cylindrical wheel called the
Leibniz wheel and a moveable carriage that was used to enter the number of digits in the multiplicand.
-because of mechanically unreliable parts, the device tended to jam and malfunction. -
Difference Engine is Inevented
-Intended to calculate numbers to the 20th place and then print them at 44 digits per minute.
-Original purpose of this machine was to produce tables of numbers that would be used by ships’ navigators.
-Navigation tables were often highly inaccurate due to calculation errors; a number of ships were known to have been lost at sea
-Although never built, the ideas for the Difference Engine led to the design of Babbage’s Analytical Engine -
Analytical Engine
-Supposed to perform a variety of calculations by following a set of instructions, or program, stored on punched cards
-Was planned to store information in a memory unit that would allow it to make decisions and then carry out instructions based on those decisions.
-The Analytical Engine was never built -
Tabulating Machine
Herman Hollerith invented in response to a contest sponsored by the U.S. Census Bureau
-Used electricity rather than mechanical gears
-Holes were punched into cards
-The location of each hole representing a speccific piece of information (male, female, age, etc.)
- They were then put into the machine and metal pins used to open and close electrical circuits -
Mark I is Invented
-Completed by a team from IBM and Harvard University led by Howard Aiken
-Used mechanical telephone relay switches to store information and accepted data on punched cards.
-Could not make decisions about the data it processed, not a computer but a highly sophositcated calculator
-Over 51 feet in lenght and weighed 5 tons
-Had over 750,000 parts
