Computer: Definition and History (Contd.)

Lin ZhongELEC101, Rice University

Electromechanical state

• A combination of electrical and mechanical states

• Electromagnetic relay to change mechanical state– Replay is a ON/OFF switch

Tabulating machine

• Invented by Herman Hollerith for 1890 U.S. Census because 1880 census took 7 years to tabulate (manually)– The origin of IBM

– Simple calculation (aggregation)

Turing Bombe

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• Used to break Enigma during WW2

Rotor: 26 mechanical states corresponding to 26 lettersElectrical current flows through a series of rotors if their letter combination makes sense

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Era of electrical states

ENIAC and vacuum tubes

Vacuum tube

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State of vacuum tubes

DiodeTriode (transistor)

Problems with vacuum tube states

• Size• Power consumption• Speed

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Era of charge states

Nobel Prize in Physics, 1956

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Transistors at nanoscale

Sunlin Chou, “Extending Moore’s Law in the Nanotechnology Era” (www.intel.com).

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Size matters

Smallest mass produced transistor 32nm

Intel 40041971

Moore’s Law

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Computing: 60 years agoWiring ENIAC with a new program

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Computing: TodayLiving among computers

“Computers” over $50 that serve me

A difference of 60 years

• ENIAC (1946)– $6 million in 2008 $– 17,468 vacuum tubes– 680 square feet– 27 tons– 15 KW power– Longest continuous period of

operation: 116 hours– 5000 operations per second

• Intel Core i7– ~$300– >730 million transistors– 263 mm²– A few ounces– <100W power– Runs forever– 76,383 MIPS (Million

Instruction Per Second)

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A difference of 10 years

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Samsung S5L8900 412MHz 128MB RAM/8-16GB Flash WiFi, Bluetooth 2.0, 3G 4.7 oz

Intel Pentium MMX 233MHz 64MB RAM/4GB Disk Ethernet 14 pounds

IBM Thinkpad 770 (1998)Apple iPhone (2008)

How about the next 10 years?

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Other states• Resistance

– Negative differential resistance (NDR)• Molecules (Reed & Tour, 1999)• Resonant tunneling diodes (RTD)

• Presence/Absence of electrons– Quantum dots (nanoscale trap)

• Spin of electrons– Spintronics

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Molecular conformation state

Collier et al, 2000

More videos about computer history

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http://www.youtube.com/user/ComputerHistory