IntroductionIntroduction In the midst of the “Information Revolution”

StorageRetrieval ComputersProcessing

Transmission and Dissemination

Communication

}FiberSatellite

IntroductionIntroduction Have been & will be more profound revolutions

Agricultural — milleniaIndustrial — a few centuriesInformation — ~ 50 years old

What is the next Revolution?What is the “Computer”

ComputerComputer Problem-solving device

Manipulates information according to a set of prescribed instructions (a program)

Early computers - mechanicalAbacusBlaise Pascal’s calculatorCharles Babbage’s devices

ComputerComputer Electro-mechanical

Hollerith’s census machineKonrad Zuse’s Z1…Z4 relay calculators

Electronic - lampsABC (Atanasoff-Berry Computer), first electronic– Special-purpose, non-programmable

ENIAC (Electronic Numerical Integrator and Calculator), first programmable

– 18000 vacuum tubes, difficult programming via plug-board

ComputerComputer 3 developments accelerated computer explosion

TransistorMagnetic core memoryThe stored program concept (Von Neumann)

Generations1940-1950 Generation I1950-1960 Generation II1960-1970 Generation III1970 onward Generation IV (VLSI)

ComputerComputer Personal Computer (PC)

Generation V?– Whole point of “generation” now moot

Tremendous advances– Hardware– Software– Communication bandwidth– Mass storage

All are fundamental changes

ComputerComputer

Digital SystemDigital System Stores and processes information in digital

formatExample: Analog vs digital audio tape

Nyquist sampling criteria

Digital SystemDigital System Other examples of digital systems

WatchesTraffic light controllers fixed functionPocket calculators

Computers: flexible/programmable– Trend: replace fixed function circuits with processors and

program them

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Digital SystemDigital System Digital versus Analog

Akin to Wave-particle dualityNature (God)

– Discrete or continuous?– Man or woman?

Digital Revolution…..

Advantages Disadvantages

Reproducibility, flexibility, speed, noise immunity….

Abstraction hierarchiesAbstraction hierarchies

Electronic technologiesElectronic technologies

I2LBiCMOS

Technology familiesTechnology families

Computer organizationComputer organization

Computer programmingComputer programming

Information representationBinaryNumeric and non-numeric (alphabets)ASCII: 7 bits plus one parity bit: 128 symbols