RAM and ROM in Computer Organization

In this tutorial, we are going to learn about RAM and ROM in computer organization.

What Are RAM and ROM in Computer Organization


RAM (Random Access Memory) is the internal memory of the CPU, which stores data, programs, and program results. It’s a read-only memory that stores data until the machine boots up. When the machine is shut off, all data is erased. In RAM, the address has no effect on the access time. It is feasible to have random access to RAM data, but it is highly expensive. RAM is volatile, which means that when the computer is shut off or if there is a power outage, the data contained in it is gone. It is little, both in terms of physical size and the quantity of data it can store.
RAM is of two types –
Static RAM (SRAM) – The term “static” refers to the fact that the memory’s contents are retained as long as power is available.
Dynamic RAM (DRAM) – DRAM, unlike SRAM, needs to be refreshed on a regular basis to keep the data current. This is accomplished by connecting the memory to a refresh circuit, which rewrites the data hundreds of times per second.


Stores critical information needed to run the system, such as the application required to start the machine. It isn’t flammable. Its data is always saved. Used in embedded systems or in situations where the programming does not need to be changed. Calculators and other peripheral devices use it. MROM (Mask ROM), PROM (Programmable read-only memory), EPROM (Erasable Programmable read-only memory), and EEPROM (Electrically erasable programmable read-only memory) are the four different types of ROM.
PROM – It can be programmed by the user. The data and instructions in it cannot be modified once they have been programmed.
EPROM – This type of memory may be reprogrammed. Expose it to UV light to delete the data on it. Delete all prior data to reprogram it.
EEPROM – Data can be wiped without the use of UV light by applying an electric field. Only a piece of the chip can be erased.
MROM – Mask ROM is a type of read-only memory that is masked off during the manufacturing process. Mask ROM, like other varieties of ROM, does not allow the user to alter the data stored in it. The process would be difficult or sluggish if it could.