Computer Hardware

Computer Hardware

1. Devices

   • Input
   • Output
   • Hybrid
   • Assistive Technology

2. Secondary Storage

   • Purpose
     • Non-volatile device that holds data until it is deleted or overwritten.
     • Secondary storage is about two orders of magnitude cheaper than primary storage.
   • Types
     • Magnetic
       • Examples
         • Magnetic tape
         • Floppy Disk
         • Hard Disk Drives
       • How it works
         • It is coated with iron oxide.
         • This oxide is a ferromagnetic material.
         • As it is a ferromagnetic material, meaning that if you expose it to a magnetic field it becomes permanently magnetized.
     • Optical
       • How it works
         • The spiral bumps on a CD starts in the center. CD tracks are so small that they have to be measured in microns which are millionths