- Computer memory, known as primary memory, is closely associated with the central processing unit but is a separate component.
- Primary memory is electronic memory without moving parts, allowing very fast access to data.
- This is important if the system is to keep up with the CPU.
- Primary memory consists of two kinds: random access memory (RAM) and read-only memory (ROM)
-
- RAM is read-write memory that can handle both data and instructions
- RAM is fast but volatile – meaning that it only function while there is a stable power flow; any power interruption will erase its content – when the power to the computer is turned off, contents of RAM disappears.
- RAM is not suitable for archiving purposes.
- ROM is read-only memory that typically contains the set of instructions needed to "boot" or start up the system when the power is turned on, e.g., Basic Input/Output System (BIOS).
- ROM contents are "burned in" to the chip and hence non-volatile – without the ROM and its contents, the computer will not be able to start anew because the CPU will not know what to do.
- Memory holds the data after it is input to the system and before it is processed; also, memory holds the data after it has been processed but before it has been released to the output device.
- Memory also holds the programs needed by the central processing unit – the stored program concept.