The father of computing history: Charles Babbage by Anja Jentzsch [email protected].

The father of computing history:Charles Babbage

by Anja [email protected]

Charles Babbage (1791 - 1871)

• born: 12/26/1791

• son of a London banker

• Trinity College, Cambridge

• Lucasian Professorship

• Mathematician and Scientist

Difference Engine

• 1822 plan for calculating and printing mathematical tables like they were used in the navy

• using the method of difference, based on polynomial functions

Difference Engine

• 1822 design 6 decimal places with second-order difference

• 1830 engine with 20 decimal places and a sixth-order difference

• 1830 end of work on the difference engine because of a dispute with his chief engineer

• 1834 plans for an improved device, capable of calculating any mathematical function

• increase of calculating speed

• never completed

Analytical Engine

Analytical Engine - Architecture

• separation of storage and calculation: – store– mill

• control of operations by microprogram:– control barrels

• user program control using punched cards– operations cards– variable cards– number cards

• more than 200 columns of gear trains and number wheels

• 16 column register (store 2 numbers)• 50 register columns, with 40 decimal digits of

precision• counting apparatus to keep track of repetitions • cycle time: 2.5 seconds to transfer a number from

the store to a register in the mill• addition: 3 seconds• conditional statements

Analytical Engine

Analytical Engine

First programmer – Ada Lovelace

• Ada Lady Lovelace, daughter of Lord Byron, was working with Babbage on the Analytical Engine

• first ideas of – algorithm representation – programming languages

• already realized:– program loops – conditional statements

Babbage’s meaning in history

• John von Neumann (1903 - 1957): universal computing machine consisting of:– memory – input / output – arithmetic/logic unit (ALU)– control unit

• based on Babbage‘s ideas

• 95 % of modern computers are based on the von Neumann architecture

Babbage’s meaning in history• Howard Aiken (1900 – 1973) developed the

ASCC computer (Automatic Sequence Controlled Calculator) – could carry out five operations, addition,

subtraction, multiplication, division and reference to previous results

• Aiken was much influenced by Babbage's writings

• he saw the ASCC computer as completing the task which Babbage had set out on but failed to complete