Definition

Noun 1. A type of computer memory that permanently stores data or instructions: The stored information can be retrieved (read) by a computer but cannot be modified, erased, or rewritten under normal operating conditions. It is non-volatile, meaning it retains its contents even when the power is turned off.

Usage

Read-only memory is used to store essential, permanent data that a computer needs to function, such as the firmware that boots up the system. - It is often contrasted with random-access memory (RAM), which is volatile and used for temporary data storage. - The term is frequently abbreviated as ROM.

Examples

• Noun:
  • The computer's basic input/output system (BIOS) is stored on a read-only memory chip.
  • Early video game cartridges used read-only memory to store the game software.
  • Unlike RAM, the data in read-only memory is not lost when you shut down your device.

Advanced Usage

• "Mask ROM": A type of ROM where the data is physically encoded during the chip's manufacturing and is absolutely immutable.
• "Programmable ROM (PROM)": A blank ROM chip that can be written to once by a user with a special device, after which it becomes read-only.
• "Erasable Programmable ROM (EPROM)": A PROM that can be erased (usually by exposure to ultraviolet light) and reprogrammed multiple times.
• "Electrically Erasable Programmable ROM (EEPROM)": A type of ROM that can be erased and rewritten electrically, without needing to be removed from the circuit. Modern flash memory is a form of EEPROM.

Variants and Related Words

• ROM (n): The standard abbreviation for .
  • The firmware update was flashed to the device's ROM.
• Firmware (n): Software that is permanently stored on a ROM chip, providing low-level control for a device's hardware.
  • The router's firmware needed an update.

Synonyms

• Non-volatile memory: A broader category of memory that retains data without power, which includes ROM.
• Fixed storage: Emphasizes the permanent, unchangeable nature of the data storage.

Related Phrases and Concepts

• "Hard-wired": Sometimes used informally to describe instructions or data that are permanently set, like in ROM.
  • The startup sequence is hard-wired into the chip.
• "Flash memory": A modern, versatile type of non-volatile memory that can be electrically erased and rewritten. While it is technically a type of EEPROM and not strictly , it is often used in roles traditionally filled by ROM (e.g., storing device firmware).

Noun

1. (computer science) memory whose contents can be accessed and read but cannot be changed