1.2 - Memory

1.2 - Memory

1. Flash Memory

   • Retains data in the absence of a power supply.
   • Advantages
     • Very reliable as no parts move.
     • Won't break if dropped or exposed to eat.
     • Compact and stores lots of data in a small space.
     • Fast access time to a hard disk.
     • Low cost and reliable.
     • Easily portable.
   • Disadvantages
     • Easily lost.
     • Wears out over time.
     • More expensive than DVD or CD.
     • Metal part can be damaged or broken.

2. Solid State

   • Doesn't move.
   • A drive using non-volatile memory as a means of storing and accessing data.

3. ROM

   • Permanent and secure.
   • Holds instructions for booting-up the computer.
   • Data is permanent, pre-written and come with a computer.

4. Disk Thrashing

   • Depends on how often it is used.
   • The process of moving apps back and forth from cache, RAM and Virtual Memory.

5. POST

   • BIOS chip performs checks.
   • Checks that components like peripheral devices are present and functioning correctly.
   • Once checks are completed, CPU starts OS.
   • If checks fail, it shows error message.

6. RAM

   • Stores programs and data currently in use.
   • Volatile.
   • Holds cache, OS apps and GUI.
   • DRAM
     • A chip that is dependant on power.
   • SRAM
     • Faster DRAM with less power.

7. Virtual Memory

   • Supports apps that can't be held by RAM.
   • Helps CPU run quicker.
   • Lots more memory to be used than there is in the system.