Historical Backgrounds...

• Primitive humans found it necessary to count and the natural instruments to use were their fingers
• With their fingers, they could show how many animals they had killed on a hunt or the number of people in a village
• To indicate large numbers, they used all 10 fingers; since humans have 10 fingers, 10 became the basis of our number system
• As time passed, life became more complex, and people needed a way to keep track of their possessions
• They began to use rocks as a way to store information, using one rock to represent each animal they owned
• Later, wanting a record of this information, they carved notches and symbols in stone or wood, an effective record-keeping method until the abacus was invented
• Abacus


  A calculating device where the user manipulates beads in a wood frame to keep track of numbers and place values
• The abacus is the only early aid to calculation that is still used today
• Abacus


  • Users can perform calculations almost as quickly as people who use calculators can
• John Napier invented Napier's Rods or Bones in 1617, a device that let you multiply large numbers by manipulating rods
• In 1642, Blaise Pascal built a calculating machine that could add and subtract
• In 1674, Baron Gottfried Wilhelm Von Leibniz designed an instrument called the Stepped Reckoner, which could multiply and divide as well as add and subtract
• Leibniz's most important contribution to the computer's evolution was binary arithmetic
• Binary arithmetic


  A system of counting that uses only two digits, 0 and 1
• George Boole devised a system of logic based on the binary system called Boolean Algebra
• In the 1930s, inventors built a computer that used this binary system, the standard internal language of today's digital computers
• The Jacquard Loom invented by Joseph Marie Jacquard used punched cards to create patterns on fabric woven on a loom
• The hole punches directed the threads up or down, thus producing the patterns
• Charles Babbage

  He called his machine the Difference Engine because it worked on solving differential equations
• Babbage was unable to complete the Difference Engine after 19 years of work using government funds and his own resources
• Babbage constructed only a few components, and people referred to his engine as Babbage's Folly
• Analytical Engine


  A system designed by Babbage in 1835 with provision for printed data, a control unit, and an information storage unit
• Augusta Ada Byron, Countess of Lovelace, tried to help Babbage and wrote a demonstration program for the Analytical Engine
• Babbage is considered the "father of computers" for his classifications of the computer into the store (memory) and the mill (processing unit)
• Herman Hollerith


  He worked at the Census Bureau in the 1880s and developed a Tabulating Machine that used punched cards to process census data
• Hollerith's Tabulating Machine relied heavily on Jacquard's punch-card idea
• Because of Hollerith's invention, the census was completed in just two years, compared to the seven years it took for the 1880 census
• Hollerith's company became known as International Business Machines, IBM, in 1924
• Howard Aiken


  He headed a group of scientists at Harvard whose task was to build a modern equivalent to Babbage's Analytical Engine
• In 1943, Aiken's team built the Mark I, IBM Automatic Sequence Controlled Calculator
• Mark I


  • 51 ft long, 8ft high, and 2ft thick; it had 750,000 parts and 500 miles of wire; and it weighed 5 tons
• The Mark I was capable of three calculations per second, it accepted information by punched cards and then stored and processed this information, with the results printed on an electric typewriter
• John Atanasoff


  In 1939, he designed and built the first electronic digital computer while working with Clifford Berry at Iowa State University
• The Atanasoff-Berry Computer (1942) used binary logic circuitry and had regenerative memory
• John Mauchly & J. Presper Eckert


  With the emergence of World War II, they believed the only way to solve the military's need for an extremely fast computer was with an electronic digital machine
• ENIAC (Electronic Numerical Integrator and Calculator) was derived from the ideas of Atanasoff's unpatented work, worked on a decimal system, and had all the features of today's computers
• ENIAC was tremendous in size, filling up a very large room and weighing 3 tons
• ENIAC


  Electronic Numerical Integrator and Calculator
• ENIAC derived from the ideas of Atanasoff's unpatented work
• ENIAC


  • Worked on a decimal system
  • Had all the features of today's computers
  • Tremendous in size, filling up a very large room and weighing 30 tons
  • Conducted electricity through 18,000 vacuum tubes, generating heat; it had to have special air conditioning to keep it cool