Both are kinds of ROM (Random Access Memory), but there are some distinctions between EPROM and EEPROM memory. But before going about the EPROM and EEPROM, let a little more about ROM. It is a kind of non-volatile memory that you cannot modify or only partially manipulate. However, you may erase and reprogram the modern ROM in different ways. EPROM and EEPROM are two customized forms of RAM. Both can be easily erased and reprogrammed, but the speed with which they can be done is rather slow. The erasing process needs some specific equipment. So, you may only do it a specific number of times.

In this article, you will learn about the difference between EPROM and EEPROM. But before discussing the differences, you must know about EPROM and EEPROM.

What is EPROM?

EPROM stands for “Erasable Programmable Read-Only Memory”. It was developed by Dov Frohman at Intel in 1971. It is a non-volatile memory that keeps data even after the power is switched off. It contains the computer BIOS utilized during the system’s start. It is a read-only memory that contents may be removed by exposing ultraviolet light on the EPROM chip. It may be recognized easily because this chip has a transparent quartz crystal window lid on top.

It is a collection of floating gate transistors. Each transistor is individually programmed using an electrical device that provides a greater voltage than the standard voltage used in digital circuits. Once programmed, the EPROM preserves its data for at least 10 years, and many of them retain data for 35 or more years. The adhesive label hides the quartz crystal window slits to protect them from the contact of camera flashes or UV lights.

EPROM may only be removed a specific number of times. After several thousand erasures, the chip becomes unreliable because the damage is accumulated in the silicon dioxide around the gates during each erasure.

Advantages and Disadvantages of EPROM

There are various advantages and disadvantages of EPROM. Some main advantages and disadvantages of EPROM are as follows:

Advantages

1. It may be reprogrammed.
2. It is very cost-effective than others.
3. It doesn’t need external memory.
4. It is very effective for testing and debugging.
5. The data may be retained even when there is no electricity.

Disadvantages

1. It is very expensive than PROMs.
2. It takes some time to remove the data.
3. It has high power consumption.
4. It uses a transistor which has greater resistance.
5. It uses ultraviolet light to erase the data.

What is EEPROM?

EEPROM stands for “Electrically Erasable Programmable Read-Only Memory”. It uses electricity to remove the content. It is a non-volatile ROM chip that is utilized in computer systems and other electronic devices to store a small quantity of data. A single data byte may be completely erased and reprogrammed using EEPROM, not just some parts of it.

It was developed by George Perlegos in 1978 at Intel. But Eli Harari developed it for the first time in 1977 at Hughes Aircraft. It is utilized as a replacement for PROM and EPROM. Removing the EEPROM chip from the computer system is not required to modify it. EEPROM executes read and write cycles very slowly than the RAM’s read and write cycles. The erase and write operations are done byte by byte.

Advantages and Disadvantages of EEPROM

There are various advantages and disadvantages of EEPROM. Some main advantages and disadvantages of EEPROM are as follows:

Advantages

1. There is no need for extra equipment to modify the contents.
2. The data is erased in an instant and electrically.
3. You may delete data from EEPROM byte by byte basis.
4. You may program and remove the contents without removing the EEPROM chip from the computer system.
5. You may reprogram the EEPROM indefinitely.

Disadvantages

1. It is quite expensive than PROM and EPROM.
2. It has a limited retention time.
3. The erasing, reading, and writing data onto the EEPROM memory require different voltages.
4. The execution time for the serial EEPROM memory is longer.

Main Differences between the EPROM and EEPROM

Here, you will learn the main differences between EPROM and EEPROM. Some main differences between EPROM and EEPROM are as follows:

1. The EEPROM content is removed using an electric signal. In contrast, the EPROM content is erased through UV rays.
2. EPROM was the first reprogrammable ROM. In contrast, EEPROM is the replacement for EPROM.
3. EPROM is easily distinguished by its appearance since it features a transparent quartz crystal window lid at the top of the chip for UV light exposure. In contrast, EEPROM is completely enclosed inside an opaque plastic case.
4. The EPROM chip has to be disconnected from the computer circuit to remove and reprogram the computer’s BIOS. In contrast, the EEPROM chip will be removed and reprogrammed within the electrical circuit to remove and reprogram the computer’s BIOS content.
5. EPROM’s transistor consumes 5 volts. In contrast, the EEPROM transistor consumes 5 volts.
6. The hot electron injection programming technique is employed in EPROM. In contrast, the tunnel effect is employed as a programming mechanism in EEPROM.
7. In EPROM, an erasure takes 15 to 20 minutes to erase the contents. In contrast, an EEPROM erasure takes 5 milliseconds to erase the contents.
8. In EPROM, the relative size of the cell is 1. In contrast, in EEPROM, the relative cell size is 3.

Head-to-head comparison between EPROM and EEPROM

Here, you will learn the head-to-head comparisons between EPROM and EEPROM. The main differences between EPROM and EEPROM are as follows:

Features	EPROM	EEPROM
Full Forms	EPROM is an abbreviation for Erasable Programmable Read-Only Memory.	EEPROM is an abbreviation for Electrically Erasable Programmable Read-Only Memory.
Basics	It uses Ultraviolet Light to remove the content.	It uses the electric signal to remove the content.
Versions	It is an older version.	It is a modern version.
Appearance	It contains a transparent quartz crystal window at the top.	It is completely encased in an opaque plastic case.
Erased and Reprogrammed	It has to be disconnected from the computer circuit to remove and reprogram the computer’s BIOS.	It will be removed and reprogrammed within the electrical circuit to remove and reprogram the computer’s BIOS content.
Transistor	Its transistor consumes 12.5 volts.	Its transistor consumes 5 volts.
Programming Technique	The hot electron injection programming technique is employed in EPROM.	The tunnel effect is employed as a programming mechanism in EEPROM.
Erasure Time	An erasure takes 15 to 20 minutes to erase the contents in EPROM.	An EEPROM erasure takes 5 milliseconds to erase the contents.
Cell Size	Its relative cell size is 1.	Its relative cell size is 3.

Conclusion

EPROM and EEPROM were designed to solve the difficulties associated with ROM and PROM. Using EPROM and EEPROM to remove and reprogram data provides chip reusability at a much faster and lower cost, providing an advantage over the limited benefits of ROM and PROM. EPROM is a modified version of PROM and ROM. In contrast, EEPROM is an even more advanced version of EPROM.