Who invented the computer?

A quick trip through the history of computer science

Charles Babbage

• [1791-1871]– English mathematician

• 1834: Analytical Engine – first concept of programmable

computer – 30x10m machine, steam-engine

powered– input (program and data)

• punch cards (like in Jacquard’s looms)• like a modern assembly language

with loops and conditional branching

– output• printer, plotter, and bell !

The Right Honourable Augusta Ada, Countess of Lovelace• [1815-1852]

– child of poet Lord Byron

• 1842-43– translates Luis Menabrea’s

memoir on the Analytical Engine

– appends a Set of Notes which specify also a method to calculate Bernoulli numbers with the Engine (the world's first computer program)

– speculates that the Analytical Engine could create graphics or compose music

“We must say most aptly that the Analytical Engine weaves algebraic patterns just as the Jacquard-loom weaves flowers and leaves,”

George Boole

• [1815-1864]– English Mathematician

• 1847– “Mathematical Analysis of

Logic”

• 1854– “An Investigation of the Laws

of Thought, on which are founded the Mathematical Theories of Logic and Probabilities “

• invented Boolean Algebra• demonstrated that logic

deduction could be developed as a branch of mathematics

Claude Shannon

• [1916-2001]– the “father of information

theory”

• 1937– with his MIT master's thesis, “A

Symbolic Analysis of Relay and Switching Circuits”, the “most important master’s thesis of the century”, essentially founded practical digital circuit design by showing how G. Boole’s algebra of logic could be used to design complex switching circuits

Alan Turing

• [1912-1954]– British mathematician– the “father of Computer Science”

• 1936– "On Computable Numbers, with an

Application to the Entscheidungsproblem“• Addressed the “decidability” of certain

mathematical & logical problems• Introduced concept of “Turing Machine”• Can you write a computer program that will

always be able to tell if another program will ever halt?

• Most modern computers are based on the concept of the “Turing Machine”

The Colossus Computer

• 1943– Designed by Max Newman

and T. Flowers at Bletchley Park, was the first combining all of digital, programmable, and electronic

• for cryptanalysis (breaking the Fish cyphers used in the communication at the highest levels of the Nazi regime)

• used vacuum tube electronics

– highly secret project (classified until 1976) it had no influence on future architectures

Howard Aiken and the Harvard Mark I

• [1900-1973]– realized Babbage’s vision

• 1939-1944– Automatic Sequence

Controlled Calculator • built by IBM for Harvard Univ.• decimal arithmetic• used electromagnetic relays• could perform all 4 arithmetic

operation (3-5 seconds for a multiplication; 0.3s for addition)

• separate memories for instruction and data (Harvard architecture)• in the final year Aiken was helped by a brilliant young student, Mrs. Grace Hopper

Admiral Grace Brewster Murray Hopper

Courtesy of the Naval Surface Warfare Center, Dahlgren, VA., 1988

• [1906-1992]– developed the first

compiler, A-0, for a computer program

J. Presper Eckert and John Mauchly

• [1907-1980 and 1919-1995]– UPenn Moore School of Elec.

Eng.

• 1944-45– ENIAC, commissioned by the US

Army for ballistic applications, was the first all-electronic general-purpose computer

• decimal arithmetic (not binary) !• re-program through rewiring !• 1,000 times faster than Mark I • 30 tons, 167 m2, 160kW power

– A modern silicon chip with equivalent processing power would be only 0.02in2

John von Neumann

• [1903-1957]– Hungarian-American mathematician

• 1945– Worked with a group at Moore

School to write “First Draft of a Report of EDVAC”, describing the architecture of a stored-program computer

• a single storage structure hold both the set of instruction on how to perform the computation and the data required/generated by the computation

• implicit separation of memory from processing unit

– von Neumann was the only author listed on the paper

von Neumann Architecture