Read only memory
ROM Edit Watch this page Read in another language Read-only memory Page issues The concept of read-only data can also refer to file system permissions . For British book publisher, see Read-Only Memory (publisher) . For other uses, see ROM (disambiguation) . an EPROM Read-only memory ( ROM ) is a type of non-volatile memory used in computers and other electronic devices. Data stored in ROM can only be modified slowly, with difficulty, or not at all, so it is mainly used to store firmware ( software that is closely tied to specific hardware , and unlikely to need frequent updates) or application software in plug-in cartridges . Strictly, read-only memory refers to memory that is hard-wired, such as diode matrix and the later mask ROM (MROM), which cannot be changed after manufacture. Although discrete circuits can be altered in principle, integrated circuits (ICs) cannot, and are useless if the data is bad or requir