Computer Dictionary of Information Technology

Programmable Read-Only Memory

(PROM) A kind of ROM which can be written using a PROM programmer. The contents of each bit is determined by a fuse or antifuse. The memory can be programmed once after manufacturing by "blowing" the fuses, which is an irreversible process. Blowing a fuse opens a connection while blowing an antifuse closes a connection (hence the name). Programming is done by applying high-voltage pulses which are not encountered during normal operation.