Hard Drives

• Ryan 2005

What it Does

• Stores info magnetically

• hard “platter” holds info

Cassette Tape vs.

Hard Drive

• must fast forward or rewind to reach specific point

• can reach info magnetically

Performance

• Data is stored in files

• Most hold 10-40 gigabytes

• most can deliver 5-40 bytes per second to CPU

Inside It

• Sealed aluminum box

• underneath board-connections for motor that spins platters

• platters hold info

• arm holds read/write heads

Tracks and Sectors

• track is a concentric circle on a platter

• sector is pie-shaped wedge on track

How it Stores Data

• Magnetically

Platters

• Hold info

Arms

• Hold read/write heads

• glide over platters and retrieve/change info

“Deleted” Info

• Hard drive like book: info stored on “pages” and “index”

• when info deleted, “index” erased of info, but is still on page

More about Deleted Data

• People can still get info off of computer after deleted unless wiping software is used and drive destroyed

Misc. Info

• Hard drives invented in 1950s

• lots of units of measurement for drive

• bit: unit of 0 or 1

• byte: 8 bits

• gigabyte: 1,000,000,000 bytes

• yottabyte: 1024 bytes

About the Author

• I am Ryan Minster, and I enjoy playing with Rubik’s Cubes and card games, such as Spades and Poker.

Bibliography• “Computer Hardware.” Apr 28 2005

<http://www.computerhope.com/help/hdd.htm>• How Stuff Works “How Hard Disks Work.” Brain,

Marshall. 25 Apr 2005. <http://www.computer.howstuffworks.com/harddisk.htm>

• “Skeletons on your hard drive.” News.com. 3 May 2005. <http://news.com.com/Skeletons+on+your+hard+drive/21001029_676995.html>