Storage and communication devices

Storage and communication devices

1. ROM

   • contents are permanent
   • contents not loss when power = out
     • non - volatile
   • cannot be written to
   • data can't be altered
   • store instructions for use of comp on start up
   • Internal or main memory
   • read only memory

2. RAM

   • Internal or main memory
     • Main memory is usually used to store data temporarily.
     • Main memory is used to store data whilst it is being processed by the CPU. Data can be put into memory, and read back from it, very quickly.
   • contents can be changed
   • contents lost when power = off
     • volatile
   • can be written too
   • data can be altered
   • store data/software/code in use or about to be used
   • Random access memory

3. Secondary / backing storage memory

   • needed to store files / data when power = off
   • stores operating system / software applications and data files
   • e.g. Hard Disks