Computer Studies Made Simple : Types of ROM / Read only Memory

Types of ROM / Read only Memory

1.PROM / Programmable Read Only Memory

This form of ROM is initially blank.

The user or manufacturer can write data and programmes on it using special devices.

The user can write data and instructions on it only once.

If there is an error in writing these instructions,the error cannot be removed from it and the chip becomes 

unusable.

2.EPROM/ Erasable Programmable Read Only memory:

This form of ROM is again initially blank.

The user or manufacturer can write data and programmes on it using special devices.

The data and programmes written on it can be erased with special devices using ultraviolet rays.

The user can write new programmes on it as well.

3.EEPROM / Electronically Erasable Programmable Read  Only memory:

In this memory,user can erase and write instructions with the help of electrical pulses.

If there is any error in writing instructions,the user can erase the contents electronically.

The contents of EEPROPM canbe modified easily.