Primary storage: RAM, ROM and virtual memory

Primary storage: RAM, ROM and virtual memory

Volatile RAM, non-volatile ROM with the boot program, and what virtual memory does when RAM is full.

Transcript

Primary storage is the memory the CPU can reach directly. It is much faster than secondary storage.

R A M, random access memory, holds the programs and data being used right now. It can be read and written, but it is volatile: when the power goes off, the contents are lost.

R O M, read only memory, holds the start up instructions, called the boot program. It is non volatile, so it keeps its contents without power, and it normally cannot be changed.

If R A M fills up, the computer uses virtual memory. Pages of data not needed right now are moved from R A M to the hard drive, and brought back when needed.

It works, but the drive is much slower than R A M, so the computer slows down.

R A M is fast and volatile. R O M is permanent. Virtual memory borrows disk space, when R A M runs out.

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