Programmable Read Only Memory

From Computing Knowledgebase

PROM is short for Programmable Read Only Memory, a memory chip on which data can be written only once. Once a program has been written onto a PROM, it remains there forever. Unlike RAM, PROMs retain their contents when the computer is turned off.

The difference between a PROM and a ROM (Read Only Memory) is that a PROM is manufactured as blank memory, whereas a ROM is physically programmed during the manufacturing process. To write data onto a PROM chip, you need a special device called a PROM programmer or PROM burner. The process of programming a PROM is sometimes called burning the PROM.

An EPROM (Erasable Programmable Read Only Memory) is a special type of PROM that can be erased by exposing it to Ultraviolet Light. Once it is erased, it can be reprogrammed. An EEPROM is similar to a PROM, but requires only an Electric Current for it to be erased.