Difference between PROM and EPROM

PROM (Programmable Read-Only Memory) is a type of ROM that is written only once. It was meant to fulfill the requirement of a group of ROMs which may contain a selected memory content. It’s memory is written just the once and programmed electrically by the user at the time or when the initial chip fabrication. the required content file is equipped by the user and inserted within the machine referred to as storage coder. There exist a fuse at every programmable association and it’s blown once the association isn’t required. 

EPROM (Erasable Programmable Read-Only Memory) is a type of ROM that is read and written optically. To write associate EPROM, its storage cells should stay within the same initial state. EPROM provides reduced storage permanency as compared to PROM as a result of the EPROM being receptive to radiation and electrical noise. in the construction of EPROM, MOS transistors are used. 

The main distinction between PROM and EPROM is that PROM may be programmed just once as it may be written only 1 time, whereas EPROM is erasable and therefore may be reprogrammed. 

Let’s see the difference between PROM and EPROM: 

S.NO	PROM	EPROM
1.	PROM is not reusable.	EPROM is reusable multiple times.
2.	PROM is inexpensive.	EPROM is costlier than PROM.
3.	Writing to PROMS is irreversible, which means its memory is permanent.	EPROM’s processes can be reversed.
4.	The storage endurance of PROM is high.	EPROM’s storage endurance of PROM is less than PROM.
5.	PROM is totally sheathed during a plastic cowl.	EPROM is boxed in during a rock crystal window so the ultraviolet radiation rays will transfer through it.
6.	PROM is a type of ROM that is written only.	EPROM is a type of ROM that is read and written optically.
7.	If there’s a miscalculation or error or bug while writing on PROM, it becomes unusable.	If there’s a miscalculation or error or bug while writing on EPROM, it will still be used once more.
8.	PROM is the older version of EPROM.	EPROM is the modern version of PROM.
9.	PROM is better than EPROM in terms of flexibility and scale.	EPROM has less flexibility and scalability.
10.	In PROM, bipolar transistors are used.	In EPROM, MOS transistors are used.