1.3 storage v2

1.3 storage v2

1. secondary storage

   • long term storage ofdata,files,software,OS
   • why do we need to store these things?
     • to access it again
     • to use software
     • to interact
   • what would happen is we didn't have secondary storage?
     • software would need to be installed every time we used it
       • you cannot save any data or files

2. Optical storage

   • a laser light creates marks in a pattern on a disk
   • a laser light detects where the marks are and translates it into a readable format
   • moderately priced
   • slow to access data
   • Types :
     • DVD
     • Blu-Ray
     • DVD ROM

3. Magnetic storage

   • move across the medium and change how magnetised that part of the medium is
     • E.g one level of the magnetism will be a 1, a second will be 0

4. Solid state

   • this is made of microchips (switches)
   • the state of the switches determine if a 1, or 0 is stored

5. Data capacity

   • traditionally 1KB = 1,024 bytes
   • GB
   • Byte
   • MB
   • Nibble
   • Bit

6. Characteristics of a storage device

   • capacity
   • speed
   • Portability
   • Durability
   • reliability

7. keywords

   • Portability
   • Durability
     • How "Strong" something is
   • Capacity
   • reliability

8. Over heads

   • 10% added to a file size
   • 1 Character = 1 byte
   • E.g. 2000 bytes = 10% 200 bytes = 2200 bytes