Hard DrivesHard DrivesHard DrivesHard DrivesBy Tommy Spaventa

Computer Basics and Computer Basics and HardwareHardware

Computer Basics and Computer Basics and HardwareHardware

• Computer hardware can be categorized into four parts

1. Processor2. Memory 3.

Input/Output 4. Storage

ProcessorProcessorProcessorProcessor

• Processors carry out and organize instructions to other hardware

• Processors are the size of a thumbnail and made of silicon

Motherboard

Processor

MemoryMemoryMemoryMemory• Memory usually

means RAM (random access memory)

• RAM stores temporary data

• Ram determines the speed of a computer

Input/Output DevicesInput/Output DevicesInput/Output DevicesInput/Output Devices

• The user gives instructions to a computer with input devices

• The computer returns feedback with output devices

Input and Output devices

StorageStorage

• Storage has more memory than RAM and is permanent

Forms of Storage

Early ComputersEarly Computers• Computers were first

built in the 1940s

• ENIAC was completed in 1945 and could process 100,000 simple calculations a second

• Apple II, shown at left, was one of the first popular home PCs

ENIAC

Apple II

What is a Hard Drive?What is a Hard Drive?

• Hard drives are hardware that store data

• They work magnetically

• Hard drives use read/write heads to both store and read data

History of Hard DrivesHistory of Hard DrivesHistory of Hard DrivesHistory of Hard Drives

• First hard drives were created in 1950s

• PCs saw the first hard drives in the 1980s. Prior to that they had none.

Diagram of Hard DriveDiagram of Hard Drive

Read/Write HeadsRead/Write Heads

• Read and write heads work by magnetically changing and reading data on the hard drive platters

• The heads never touch the platters since they are supported by a cushion of air

PlattersPlatters• The platters store all of

the information

• Platters are mirror smooth and some can show reflections

• Platters are not very large, as you can see with the image to the left

• Hard Drives can have multiple platters

How Hard Drives Work How Hard Drives Work MagneticallyMagnetically

• When a write head passes over a disk the information is changed magnetically

• A read head reads that magnetic change by going over the disk backwards

What happens when you turn off a computer?

What happens when you turn off a computer?

• When ever a computer is powering down, the hard drive heads to the “landing zone”. This is an area where no data is stored. After about 50,000 landings, hard drives have a significant chance of failing.

About the AuthorAbout the Author• I’m Tommy Spaventa. I

was born in Argentina on October 26, 1990. I have one brother and enjoy tennis, swimming and soccer.

BibliographyBibliography• Gookin, Dan, and Sandra Clemons. PCs For Dummies 2nd Edition.

New York: Wiley Publishing, 2003.

• Norton, Peter. Essential Concepts. Columbus: Glencoe/McGraw-Hill, 1999.

• Wales, Jimmy. Hard Disk. Wikipedia. 28 Apr. 2004. <http://en.wikipedia.org/wiki/Hard_disk>

• “Computer”. World Book Encyclopedia. New York. 2003.

• Hard Disk Drives. PC Guide. 28 Apr. 2004. <http://www.pcguide.com/ref/hdd/index-c/html>