Memory

Memory

1. RAM

   • The main memory in the computer
   • Required for...
     • Operating system
     • Loaded applications
     • Any data currently in use
   • Volatile
   • Types
     • Static
       • More complicated
       • Use four or five transistors wired together
         • Don't lose charge so can store data without refreshing while powered
         • Used for cache memory
     • Dynamic
       • Has one transistor and a capacitor
       • Has to be refreshed every few milliseconds

2. ROM

   • Read only memory
   • Non volatile
   • Stores the boot up sequence in the computer
   • Cannot be over written by the computer

3. Virtual memory

   • An allocated part of your hard drive to act as an over-run for your RAM

4. ROM chips and flash memory

   • Uses a group of transistors wired together so that they can retain data
   • ROM chips are programmed during manufacture
   • Flash memory
     • Low cost
     • Portable
     • Removable storage
     • Not as fast as RAM, but faster than magnetic hard disk