What is ROM in Computer? Types of ROM

What is ROM in Computer? 

ROM stands for Read Only Memory. One of the most important Read Only Memory function is preparing the computer system for usage. The instructions provided by ROM can only be read by users. Users are not allowed to change or delete these instructions. Computer users are unable to write any new information into the ROM.

Unlike Random Access Memory, ROM can store data and instructions permanently. It is a non-volatile memory as data and instructions are not lost in case the computer shuts down. Instead the instructions are loaded automatically when we switch on a computer system.

Types of ROM

Let's talk about different types of ROM. Read Only Memory consists of three basic types given below:

1. PROM

PROM is abbreviated as Programmable Read Only Memory. Initially, a PROM is blank. However; with the help of special devices, the manufacturer can write data and instructions into this memory. There is a considerable drawback of using a PROM that PROM allows a manufacturer to write data and instructions on it only once. That's why manufacturers find it really difficult to work with PROM because the errors in the instructions cannot be removed if a user has written the instructions once and. Consequently, the chip becomes unusable.

2. EPROM

This is one of the useful types of ROM. EPROM stands for Erasable Programmable Read Only Memory. Like a PROM, we find an EPROM initially blank and by using special devices, users or manufacturers can write the data and instructions into EPROM. This type of ROM is really favorable for the manufacturers as the data written on EPROM can be erased if manufacturer finds any mistake in his written instructions. Thus it’s more convenient to work with this type of ROM.

3. EEPROM

EEPROM stands for Electronically Erasable Programmable Read Only Memory. This is the advanced type of ROM. A manufacturer can write or erase the data and instructions into an EEPROM with the help of electrical pulses. The user can erase the written contents electronically if he finds any error in written data later on. It's no sweat to erase or modify the data of EEPROM.