Memory

Memory

1. Virtual Memory

2. ROM

   • Read Only Memory
   • Used to store to BIOS on the computer
     • The basic software that starts the computer before the operating system loads
   • Non-Volatile
     • Even after power is lost, data is kept

3. RAM

   • Random Access Memory
     • It's possible to directly access any memory location in a random order
   • Volatile
     • Loses data when power is lost
   • Although other types of memory are also random access, the volatile nature and primary storage of RAM defines it
   • Increasing the cache reduces the need to access RAM so often, and therefore the computer speeds up
     • Increasing the RAM reduces the need to access slower Secondary Storage so often, and the computer speeds up more
   • Static RAM [SRAM]
     • Uses transistors to store the data
     • Doesn't need to be constantly refreshed
     • Faster
   • Dynamic RAM [DRAM]
     • Uses capacitors to store data in 'bits'
     • As capacitors lose their charge, DRAM must constantly read and write back what is in RAM
   • When you run a program, it is first copied from secondary storage to RAM
     • It is then run by the CPU which can access RAM directly.