Memory

Memory

1. RAM

   • Used as main memory in the computer - stores file/data/programs that are being used
   • Read and write
   • Operating system is copied from secondary storage to RAM when the computer is turned on
   • Volatile
   • When software and files are open, they are copied secondary storage to the RAM
   • Slower than the cache but faster than the secondary storage

2. ROM

   • Volatile
   • Read and Write
   • Chip built into the motherboard
   • contains all the instructions a computer needs to boot up. This is called the BIOS
   • Computer turns on - CPU reads instructions from the ROM - performs self checks and sets up the computer e.g. checks memory is working, what hardware devices are attached and copies the operating system to the RAM

3. Virtual Memory

   • When Ram is full it moves data that has not been recently used to secondary storage called virtual memory
   • Used if too many applications are open at one time
   • If the CPU wants to read data on the virtual memory it must move it back to the RAM