Computers - EdexcelRead only memory

The CPU is the part of a computer system that runs programs and processes data. CPUs use the fetch-decode-execute cycle to do this. The CPU is an internal component of the computer hardware. Operating systems and utilities are programs used to manage and maintain the computer system.

Part ofComputer SciencePrinciples of computer science

Read only memory

Read only memory (ROM) is non-volatile. Its contents are not lost when the computer is switched off.

ROM can be read from, but not written to, hence the term ‘read only’. This makes ROM ideal for storing and that are needed for the computer to run. These instructions and data are usually programmed by the computer's manufacturer and cannot be overwritten.

The Basic Input Output System (BIOS) is an example of a program that is stored in ROM. The BIOS runs as soon as the computer is switched on. It checks that the is functioning correctly, then loads the computer's operating system (OS). Because the BIOS is always needed, it is stored in ROM.

Next page
Secondary storage
Previous page
The role of main memory

More guides on this topic

Related links