Personal Personal ComputersComputers

PenetrationPenetration• Personal computers are now in close

to four-fifths of American households• It took telephones 85 years to get to

this penetration rate

Brief HistoryBrief History• Herman Hollerith: 1890

– Working for the government to help count the census

– Data was input to a “memory”– Processed by a central processing unit– Results were output in a special format

Brief HistoryBrief HistoryBig ComputersBig Computers

• ENIAC– Electronic Numerical Integrator and

Computer– Introduced at end of World War II

• UNIVAC appeared in 1950• IBM ruled the roost

Brief HistoryBrief HistorySmall ComputersSmall Computers

• MITIS Altair 8800 in 1975• Apple II about 1977

– Was leader until early 1980s

• IBM Personal Computer 1981– Used an Intel chip

• Clones followed…

800 Pound Gorilla800 Pound Gorilla• Microsoft

– Bill Gates drops out of school to start it– By 2002 94% of PCs in the world have

some version of Microsoft Windows on them

Key ComponentsKey Components• Vacuum tube• Transistor 1947

– Begin the miniaturization of computers

• Integrated circuit 1958– Transistors on one chip– CPU goes from size of building to size of

a wafer

• Motherboard holds all the circuits

Computer MemoryComputer Memory• RAM

– Random Access Memory– Active when computer is turned on

• Not permanent

• Storage Memory– “Book” or permanent memory

• Both measured in megabytes or gigabytes

Storage MemoryStorage Memory• Hard drive• Floppy diskette• Zip diskette• Keydrives/Jumpdrives/Flashdrives• Compact Discs (CDs)• Digital Versatile or Digital Video

(DVD)

Input DevicesInput Devices• Keyboard• Mouse• Microphone• Scanner• Camera• Joystick• USB device

SoftwareSoftware• Applications or programs• Operating System

Moore’s LawMoore’s Law• Gordon Earle Moore

– Co-founder of Intel– Computing power doubles about every

18 months

Central Processing UnitCentral Processing Unit• 32-bit

– Most PCs have this type

• 64-bit– Latest Mac has this type– New PCs have this type– Better graphics on faster computers

TrendsTrends• Keydrives and other flash media

storage devices• Portable PCs (40% of market in 2003)• Flat panel monitors (about 50% of

sales in 2004)

PotpourriPotpourri• Computer Industry sold $41 billion in

equipment in 2002– Computers make up 67% of that amount

• Intel has 83% of chip market• About 40% of business software in

the world is pirated• Convergence, convergence,

convergence