Charles Babbage

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Charles BabbagesAnalytical engine

• By Nicholas Lucaroni

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Difference Engine

• Uses the differences method to tabulate
  polynomials.
• Construction wasnt completed
• Internal Friction and Gearing were not accurate
  enough.
• Kept changing his mind on the design.

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Analytical Engine

• First attempt at a digital computer, at 1834.
• Programmable, could solve more then just
  polynomials.
• Had a store and a mill which would represent
  memory and processor today.
• Input and output was controlled through punch
  cards.
• Ran off a steam engine.

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The Mill and Store

• The store could hold 1000 50 digit numbers.
• The Mill could perform any basic operation
  (addition, subtraction).
• and used normal base 10 arithmetic.

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Input / Output

• Input and output was on punch cards, similar to
  the ones used in looms at that time.
• Output also had a printer, curve plotter, and a
  bell.
• A separate

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Three Types of Punch Cards

• Operation Cards
• Perform Arithmetic operations
• Combinatorial cards
• Advance/back cards (perform loops and jumps)
• Number Cards
• Numerical constants, usually punched by the
  machine for later use.
• Variable Cards
• Direct transfer of values to serve as arguments
  for operations.

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The end results

• Never built due to technology limitations with
  the precision of gears, cogs and wheels.
• Also limited by funding, due to the scrap of his
  difference engine project before.

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Other resources

• Original texts can be found at
• http//www.fourmilab.ch/babbage/contents.html
• Emulator of analytical engine in Java
• http//www.fourmilab.ch/babbage/websim/ae.html