1. Hard Disk Geometry

2. Physical Sizes ( Also called Form Factor) Hard Drives currently come in 2 main sizes: 2.5” and 3.5” 2.5” Drives are for laptop computers. 3.5” drives are for desktop computers. Both sizes can be placed into cases and used as external drives that connect to the computer with a USB cable.

3. What is a hard drive for?

4. Back to Binary – 0s & 1s, off & on, + & -, positive & negative Every document, every picture, every game, every website, every computer program is made up of one or more files. Every file is a block of arbitrary information, or resource for storing information. Information is described using groups of words, symbols, and numbers. Words are made of letters. or symbols. and, along with numbers are made of characters. J ɶ 3 % c * ) 43 ╠ ~ abc ¥ ξ Every character is made of bytes. Every byte is made up of bits A bit is either a 0 or a 1, on or off, + or -, positive or negative. A hard disk drive is a magnetic storage device. It records with positive and negative charges, thus recording information.

5. Hard Disk – Internal Geometry Disks are first divided into concentric circles called Tracks are then divided into blocks called Sectors typically hold 512 bytes of data The disk spins at RPMs. Current drives operate at 5,400 RPM, 7,200RPM, 10,000PRM and 15,000RPM. Data is magnetized on the disk at either positive or negative charges (just like binary)