System Memory and Storage

System Memory and Storage

1. Main Memory/Storage

   • ROM
     • Read Only Memory
     • Is a constant, non-volatile memory which contains instructions that boots the computer up.
     • Contains BIOS (Basic Input/Output system) which contains programs to load the hardware
     • Contains Firmware (Permanent Software embedded into ROM) e.g. a Microcontroller, a part of the microprocessor that tells it what actions to take.
   • RAM
     • Is a temporary, volatile memory which stores data and programs you are working on
     • Two Types of RAM
       • DRAM
         • Dynamic RAM is a type of memory that is typically used for data or program code that a computer processor needs to function and refreshes periodically.
       • SRAM
         • Static RAM is a type of memory which retains bits of data in its memory as long as power is being supplied. It does not have to be periodically refreshed.
     • Random Access Memory
   • The main storage region of a computer, to which the CPU has immediate or direct access to

2. Secondary Storage

   • Three Types of Storage
     • Optical
       • Data recorded by marking patterns with a laser light on a disk. Patterns can be translated and read again with said laser light e.g. DVDs , CDs
     • Magnetic
       • Data is stored by using different patterns of magnetization in a magnetizable material to store data. Non-Volatile e.g. Hard Drive
     • Solid State
       • Made out of Microchips which store data electronically e.g. SD Cards, Memory Cards
   • Virtual Memory
     • An area of secondary storage that is used like RAM; Is temporary storage and is located on the hard disk