500 B.C.

Abacus

unknown

·        Crude calculation instrument

·        each bead in groups of 5 = 1 unit

·        each bead in groups of 2 = 5 units

·        count or add by pushing beads towards bar

1600s

Pascaline

Blaise Pascal

·        French tax officer’s son

·        8 gears (like odometer) stood for each place

·        slow, broke often, only inventor could repair

·        clerks wouldn’t use -- unpopular

1676

Leibnez

Gottfried Wilhelm von Leibniz

·        German mathematician

·        Could add, subtract, multiply, divide & calculate square roots

·        Mechanical calculators based on it

1801

Jacquard Loom

Joseph Marie Jacquard

·        Designed a weaving loom to use cardboard punched cards – 1 card for each design linked in a series

·        DATA could be CODED in cards

·        Cards could be LINKED in a PROGRAM

1822

Difference Engine

Charles Babbage

·        English mathematician who used calculation tables that often had errors from clerk’s tabulations & printer errors

·        Machine to figure out and print exactly

·        Could only do one type of problem so new machine for each kind of problem

Analytical Engine

Charles Babbage

·        This one could be changed to do different problems

·        Read programs from punched cards, calculate and store problems, print

·        Died before it was completed

·        Called the “Father of Computers”

Augusta Ada Byron

·        Helped Babbage’s son with father’s notes to complete machine

·        Added her own notes

·        Called the “First Programmer”

1890

Tabulating Machine

Herman Hollerith

·        U.S. Census contest to speed up the tabulation process

·        Machine could read & sort data from punched card answer sheets

·        Brushes passed over punched cards, finds a hole and sent electric circuit to counting dials that increase the data for that answer

·        Started Tabulating Machine Company in 1896- sold in 1911 which became International Business Machines

1944

Mark I

Howard Aiken

·        First automatic general purpose mechanical calculator

1939

ABC

John Vincent Atanasoff & Clifford Berry

·        First to use VACUUM TUBES to pass through electricity

·        First to use BINARY NOTATION to indicate electricity flowing or not flowing (on/off)

·        For special work only

WWII

ENIAC

John Mauchley & J. Presper Eckert

·        First general purpose electronic digital computer

·        Used 18,000 vacuum tubes

·        Completed a problem in 20 seconds that took scientists 40 hours to do

·        Work on the hydrogen bomb, weather & cosmic rays

UNIVAC

Mauchley & Eckert

·        First commercial general purpose computer

1950

EDVAC

John von Neumann

·        Used the stored program concept

·        One machine could do many tasks by storing different programs on punched cards in computer’s memory