What is ROM | Tyoes of ROM

What is a ROM and Types of ROMs | 2020

What is a ROM?

• ROM full form is Read Only Memory.
• ROM stores data without electrical current.
• It is the ROM (Read Only Memory) or us sometime called non-volatile (Permanent) Memory. As it is Not erased when the system is switched off.
• Has contents which are fixed when the chip is manufactured.
• Holds the Bootstrap loader part of the operating system.

Types of ROMs :

1. PROM (Programmable Read Only Memory)
2. EPROM (Erasable Programmable Read Only Memory)
3. EEPROM (Electrically Erasable Programmable Read Only Memory)

1. PROM :

• PROM is blank ROM chip on which a programmer can write permanently but once written cannot be changed or modified.
• Once the PROM has been written is permanent and cannot be erased or deleted.
• ROM use for important program like BIOS of a device.

2. EPROM :

• Erasable Programmable Read Only Memory, EPROM is a non-volatile memory chip.
• If exposed to ultraviolet light an EPROM can be reprogrammed if needed , but otherwise does not accept or save any new data.
• Hardware manufacturers use EPROM when it may be needed that the data contained on the EPROM neecded to be changed .

3. EEPROM 

• EEPROM full form is a Electrically Erasable Programmable Read Only Memory.
• It allows its entire contents to be electrically erased then rewritten electrically , so that they can not been removed from the computer.