Computing 1.3

Computing 1.3

1. Secondary storage is the long term storage of data and files

   • We need to store these things in order to access them again later
     • And to interact with the computer
   • Without secondary storage you couldn't save anything
     • And software would need to be installed each time we use it

2. Types of storage are Optical

   • Magnetic
     • Read/write move across the medium and change how magnetised that part of the medium is
       • Cheapest
       • ok reliability
       • Not good durability
       • Not good portability
       • Ok speed
       • Big capacity
   • Solid state
     • Made of microchips (switches)
       • Most expensive
       • Most reliable
       • Most durable
       • Most portable
       • Fastest
       • Ok capacity
   • A laser light creates marks in a pattern on the disk
     • A laser light detects where marks are and translates this into a readable format
       • Not very good capacity
       • Ok cost
       • Not very reliable
       • Ok durability
       • Ok portability
       • Not very good speed
       • Not very good capacity

3. 1KB=1000 bytes

   • Traditionally it =1024 but in exams we use =1000