Computer Hardware

Basic Computer Concepts

Data Representation andDigital Electronics

ØData Representation

vmakes it possible to convert letters,sounds, and images into electrical signals

ØDigital Electronicsvmakes it possible for a computer tomanipulate simple “on” and “off” signalsto perform complex tasks

Computer Hardware

Basic Computer Concepts

Digital DataRepresentation

Why are computers digital ?

Ø Digital Devicevworks with discrete -distinct or separate -data or digits, such as 1 and 0

ØAnalog Device

vworks with continuous data

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Computers are digital because computerdesigners have found it to be a relativelysimple, dependable, and adaptabletechnology.A digital computer is a simpler technologythan an analog computer.Most computers use the simplest type of digitaltechnology, their circuits have only twopossible states.

Computer Hardware

Basic Computer Concepts

Digital DataRepresentation

How can a computer represent numbers usingbits ?

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Computers represent numeric data using thebinary number system, also called “base 2”

Numeric Datavthe numbers that might be used inarithmetic operations

ØBinary Number System

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has only two (2) digits : 0 and 1allows computers to represent virtually anynumber simply by using 0s and 1sconveniently translates into electrical “on”and “off” signals

Computer Hardware

Basic Computer Concepts

Digital DataRepresentation

How can a computer represent words andletters using bits ?

Ø Character Data

vconsists of letters, symbols and numeralsthat will not be used in arithmeticcalculations

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A digital computer uses a series of bits torepresent letters, characters, and numerals.ASCII

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pronounced as “ ASK ee”stands for American Standard Code forInformation Interchangerequires only seven bits for each character

Ø Extended ASCII

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a superset of ASCIIuses eight bits to represent eachcharacterprovides codes for 128 additionalcharacters

Computer Hardware

Basic Computer Concepts

Digital DataRepresentation

How can a computer represent words andletters using bits ?

Ø EBCDIC

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pronounced as “EB seh dick”stands for Extended Binary Coded DecimalInterchange Codean alternative 8-bit code usually used byIBM mainframe computers

Ø UNICODE

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pronounced as “YOU ni code”provides codes for 65,000 characters andmakes use of 16 bits

Computer Hardware

Basic Computer Concepts

Digital DataRepresentation

How does a computer convert sounds andpictures into codes ?

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A computer must somehow digitize colors,notes, and instrument sounds into 1s and0s, in order to work with sounds andpictures.Computers convert colors and sounds intonumbers, which can be represented bybits.A red dot on your computer screen mightbe represented by 1100, a green dot by0010.

Computer Hardware

Basic Computer Concepts

Digital DataRepresentation

When a computer works with a series of 1s and0s, how does it know which code to use?

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All of the things that computer works with isstored in files as a long series of 1s and 0s.The computer needs to know whether tointerpret those 1s and 0s as ASCII code, binarynumbers, or the code for a picture or sound.Most computer files contain a file header withinformation on the code that was used torepresent the file data, to avoid confusion.A computer can now tell how a file’s contentswere coded by reading the header information.

Computer Hardware

Basic Computer Concepts

Digital Electronics

How can I tell the difference between bits andbytes?

Ø bit

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binary digitcan be further abbreviated as a lowercase“b”

Ø byte

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composed of eight (8) bitsusually abbreviated as an uppercase “B”

Ø nibble

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composed of four (4) bitsa halfway between a little bit and a bigbyte

ØStorage space is usually expressed in byteswhile transmission speeds are expressed inbits.

Computer Hardware

Basic Computer Concepts

Digital Electronics

How does a computer store and transport all ofthose bits ?

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Bits take the form of electrical pulses that cantravel over circuits.The circuits, chips, and mechanicalcomponents forming a computer are designedto work with bits.These components are housed within thecomputer’s system unit.

Computer Hardware

Basic Computer Concepts

Digital Electronics

How do chips fit together to make a computer?

Ø Motherboard

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also known as main boardthe computer’s main circuit boardhouses all essential chips and providesconnecting circuitry between them

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Some chips are permanently soldered in place,while other chips are plugged into specialsockets and connectors.The chips might be gathered together on aseparate small circuit board, which can thenbe plugged into a special slot-like connector.

Computer Hardware

Basic Computer Concepts

Microprocessor Basics

ØMicroprocessor

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sometimes known as processoran integrated circuit designed to processinstructionsthe most significant component ofcomputer and usually the most expensivesingle componentexecutes instructions that are provided bya computer program

Ø Instruction Set

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list of instructions that a microprocessorcan performhardwired into the processor’s circuitrycomprising of basic arithmetic and logicaloperations, fetching data, and clearingregisters

Ø Memory

v is the electronic that holds place forinstructions and data which themicroprocessors can reach quickly

Computer Hardware

Basic Computer Concepts

Today’s Microprocessors

Which companies produce most of today’spopular microprocessors ?

Ø Intel

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world’s largest chipmaker and supplies asizeable percentage of themicroprocessors that power personalcomputersintroduced the world’s firstmicroprocessor , the 4004, during 1971

ØAMD (Advanced Micro Devices)

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Intel’s chief rival in the PC chip marketproduces microprocessors that work justlike Intel's chips, but a lower price

Computer Hardware

Basic Computer Concepts

Today’s Microprocessors

Which of the microprocessors is the best ?

Ø Intel

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Original Pentium : 1993Pentium II : 1997Pentium III : 1999Pentium IV: 2000Itanium : 2001Celeron processors : Intel’s budget model

Ø AMD

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Athlon processors : Direct competitors toIntel’s Pentium lineDuron processor : AMD’s budget model

ØThe microprocessor that’s “best” for youdepends on your budget and the type of workand play that you plan to do.