The PROM stands for Programmable Read-Only Memory, which is a type of non-volatile computer memory that can be programmed only once. Unlike RAM (Random Access Memory), which is volatile and can be read and written to repeatedly, the contents of a PROM are permanent and cannot be changed once they have been written.
PROMs are used to store permanent data such as firmware, boot codes, and other types of low-level software that are required to run a computer or device. They are also commonly used in embedded systems, such as those found in automobiles and consumer electronics.
PROMs can be programmed by a user or manufacturer using a specialized device, such as a PROM programmer, which uses high voltage to write the data onto the PROM. The data written onto the PROM is stored permanently, even when the power to the device is turned off.
PROMs come in a variety of sizes and capacities, with some being as small as a few kilobits and others being as large as several megabytes. The contents of a PROM can also be read by a computer or device, but they cannot be changed once they have been written.
In conclusion, PROM is a type of non-volatile computer memory that is used to store permanent data such as firmware, boot codes, and other types of low-level software. Unlike RAM, the contents of a PROM cannot be changed once they have been written and are stored permanently, even when the power to the device is turned off. PROMs are commonly used in embedded systems and come in a variety of sizes and capacities.