ROMRead only memory. This is non-volatile memory or storage containing data that cannot be changed. is non-volatile memoryA form of computer memory that stores data even when not powered. primary memoryThe part of a computer that stores data.. Its contents are not lost when the computer is turned off.
The purpose of ROM in a computer system
ROM can be read from, but not written to, hence the term 'read-only'. This makes ROM ideal for storing instructionA single action that can be performed by a computer processor. and dataUnits of information. In computing there can be different data types, including integers, characters and Boolean. Data is often acted on by instructions. 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 BIOSBasic input output system - the basic firmware that is embedded in the computer ROM chip used to start a computer. 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 hardwareThe physical parts of a computer system, eg a graphics card, hard disk drive or CD drive. is functioning correctly, then runs a second program known as the bootup or bootstrap program that loads the computer's operating systemThe software that manages the hardware and software resources in a computer system. from the hard drive into the RAM. The BIOS is always needed so it is stored in ROM.
