EPROMEEPROM

EPROMEEPROM, often stylized as EPROM/EEPROM, refers to two types of non-volatile computer memory. EPROM, which stands for Erasable Programmable Read-Only Memory, is a type of memory chip that can be erased by exposure to ultraviolet light and then reprogrammed. EEPROM, or Electrically Erasable Programmable Read-Only Memory, is a similar type of memory but can be erased and reprogrammed electrically, making it more convenient for data updates.

Both EPROM and EEPROM are used to store firmware or other data that needs to persist even when the power is turned off. EPROM chips typically have a quartz window on the top, allowing the ultraviolet light to reach the memory cells for erasure. Once erased, the chip can be reprogrammed. EEPROM, on the other hand, does not require physical exposure to light. Instead, a higher voltage is applied to specific pins to erase and rewrite individual bytes or blocks of data.

EEPROM offers more flexibility for in-system reprogramming compared to EPROM, which often requires removal from the device for erasure. EPROM was a common choice for storing BIOS in early personal computers and for embedded systems where infrequent updates were expected. EEPROM found applications in storing configuration settings, calibration data, and firmware in a wider range of devices, including printers, automotive systems, and consumer electronics, due to its easier update process. While newer non-volatile memory technologies like Flash memory have largely superseded both EPROM and EEPROM in many applications due to their higher density and faster write speeds, understanding these foundational memory types provides insight into the evolution of digital storage.