1.2 | Memory

1.2 | Memory

1. Key Words

   • RAM - Random Access Memory
   • ROM - Read Only Memory
   • CPU - Central Processing Unit
   • Volatile - gets emptied when the power is turned off
   • Firmware - permanent software programmed into RAM
   • Non-Volatile - doesn't leave the data when the device is turned off
   • BIOS - Basic Input Output System
     • Basic I/O system that contains programs to load the hardware
   • Disk Thrashing - when a computer's virtual memory subsystem is in a constant state of paging
     • Paging - moving programs from virtual memory to RAM / cache
     • Backup - to have a second copy of data and software

2. What is RAM?

   • RAM - Random Access Memory
   • Fast temporary memory
   • Stores applications and data
   • If a computer loses power, everything in RAM is lost
   • What is stored in RAM?
     • Operating System
     • Applications
     • GUI - Graphical User Interface
     • Programs & Data currently in use.
   • Volatile

3. What is ROM?

   • ROM - Read Only Memory
   • Memory that cannot be changed by a program or user.
   • Retains its memory even when the computer is turned off.
   • Non - Volatile
     • Flash memory is also non-volatile.
       • What is Flash Memory?
         • It is solid.
         • There are no moving parts.
         • AKA. EEPROM
         • Used in solid state media.
         • What are its uses?
           • USB Drive
           • Memory Card
           • Durable, reliable, low cost.
           • Can get lost, wear out.
   • What is in ROM?
     • Boot Strap - loads OS
     • BIOS - embedded in the ROM chip to start a computer

4. What is Virtual Memory?

   • A section of a computer storage drive which is temporarily used as RAM.
   • Written onto a file on hard drive / memory.
   • Secondary storage.
   • OS sets up virtual memory using VMM