1.2 memory

1.2 memory

1. primary memory

   • memory used to store data and instructions that are required by the CPU

2. R.A.M

   • Random access memory
     • volatile memory
       • used to store data and instructions which are needed by the CPU
         • refered to as main memory
           • stores the user data
             • part of the operating system
               • memory can be written to or read from

3. R.O.M

   • Read only memory
     • used to store the boot sequence as this should never be changed
       • non-volatile
         • used to store Bios
           • Memory can only be read from and not written to

4. Flash-memory

   • Electrons are forced into a layer between tow barriers
     • use high electric current

5. secondary storage

   • R.A.M
     • Cache memory
       • CPU

6. Volatile

   • storage which needs to have power to store data
     • if power is lost data is lost
       • R.A.M is volatile

7. non-volatile

   • storage which does not lose its contents when the power is lost
     • R.O.M is non-volatile

8. static R.A.M

   • Uses 5 transistors which are wired together to represent each bit
     • no need to be refreshed
       • more wiring per bit

9. Dynamic R.A.M

   • Contains 1 transistors and capacitor that hold charge briefly
     • this needs to be refreshed every few milliseconds

10. bootstrap loader

    • a small program
      • loads the operating system
        • once the operating system is loaded it takes care of the rest

11. viirtual memory

    • when R.A.M is full a selection of the hard drive can be used to store data
      • if power is lost data is lost