1.3 storage mind map

1.3 storage mind map

1. The location of the POST sequence

   • Power On Self- Test
     • BIOS chip performs checks
     • Makes sure components are present and fuctional
     • Once completed successfully, the OS boots up
   • Uses the BIOS instructions
     • Basic Input Output System

2. ROM

   • Non Volatile form of memory
   • Retains its information through power off
   • Contains data that is pre-written and permanently written on a ROM chip
   • Considered as permanent
   • Read-Only Memory

3. RAM

   • A volatile form of memory
   • Contains the data and programs currently in use
   • Can be DRAM or SRAM
     • DRAM - Dynamic RAM
       • Slower as needs to be refreshed thousands of times per second
     • SRAM - Static RAM
       • Faster as doesnt need to refresh
       • Expensive and Less Common
   • Random Access Memory

4. Flash Memory

   • Can be easily broken
   • Relatively Cheap
   • Examples include USB drives and Memory Cards
   • Can very easily be broken and/or stolen
   • Can be used to back up computational data

5. Virtual Memory

   • A simulated form of memory found on the hard drive
   • Created by the Operating System (OS)
   • It is needed to make more memory than is actually in the system
   • Creates the virtual memory manager
     • Which then creates a file on the hard drive
       • Now the OS can address the memory
   • It's needed when you need to run things that RAM can't support.

6. Solid State Media

   • no moving parts
   • Uses Flash Memory

7. Disc Thrashing - The process the system uses to move data between Virtual Memory, RAM and Cache.

   • Depends on the frequency of the data, how often it's used.