EPROM. The small quartz window admits UV light during erasure.

An EPROM, or erasable programmable read-only memory, is a type of computer memory chip that retains its data when its power supply is switched off. In other words, it is non-volatile. It is an array of floating gate transistors individually programmed by an electronic device that supplies higher voltages than those normally used in electronic circuits. Once programmed, an EPROM can be erased only by exposing it to strong ultraviolet light. EPROMs are easily recognisable by the transparent window in the top of the package, through which the silicon chip can be seen, and which admits UV light during erasing. Image File history File linksMetadata Download high resolution version (1275x665, 575 KB) Title : EEPROM : The first INTEL EPROM, the 1702 (1971). ... Image File history File linksMetadata Download high resolution version (1275x665, 575 KB) Title : EEPROM : The first INTEL EPROM, the 1702 (1971). ... Read-only memory (ROM) is a class of storage media used in computers and other electronic devices. ... Non-Volatile Random Access Memory (NVRAM) is a computer memory chip which will not lose its information when the power is lost. ... The floating gate transistor is a variant of transistor that is commonly used for non-volatile storage such as flash, EPROM and EEPROM memory. ... Ultraviolet (UV) light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than soft X-rays. ... General Name, Symbol, Number silicon, Si, 14 Chemical series metalloids Group, Period, Block 14, 3, p Appearance dark gray, bluish tinge Atomic mass 28. ...

As the quartz window is expensive to make, OTP (one-time programmable) chips were introduced; the only difference is that the EPROM chip is packed in an opaque package, so it can not be erased after programming. OTP versions are manufactured for both EPROMs themselves and EPROM-based microcontrollers. Quartz is amongst one of the most common minerals in the Earths continental crust. ... A One Time Programmable (or OTP) is an electronic chip that contains programmable read-only memory (PROM). ...

A 32KB (256Kbit) EPROM.

However, OTP EPROMs are being increasingly replaced by EEPROM chips, which offer similar price of silicon and reprogrammability in a windowless package. Image File history File linksMetadata Download high resolution version (1124x1550, 388 KB) This file is licensed under the Creative Commons Attribution ShareAlike 2. ... Image File history File linksMetadata Download high resolution version (1124x1550, 388 KB) This file is licensed under the Creative Commons Attribution ShareAlike 2. ... To meet Wikipedias quality standards, this article or section may require cleanup. ...

This 8749 Microcontroller stores its program in internal EPROM.

A programmed EPROM retains its data for about ten to twenty years and can be read an unlimited number of times. The erasing window must be kept covered to prevent accidental erasure by sunlight. Old PC BIOS chips were often EPROMs, and the erasing window was often covered with a label containing the BIOS publisher's name, the BIOS revision, and a copyright notice. Image File history File links Image of the `fabled 8048 with EPROM An Intel 8048 version (actually made by NEC) with UV EPROM. This one lived in a Timelapse traffic counter of some sort, which served with the California department of transportation before being downsized several years ago and sent... Image File history File links Image of the `fabled 8048 with EPROM An Intel 8048 version (actually made by NEC) with UV EPROM. This one lived in a Timelapse traffic counter of some sort, which served with the California department of transportation before being downsized several years ago and sent... The Intel 8048 microcontroller (µC), Intels first µC, was used in the Magnavox Odyssey² video game console and (in its 8042 variant) in the original IBM PC keyboard. ... A microcontroller (MCU) is a computer-on-a-chip used to control electronic devices. ... Phoenix AwardBIOS on a standard PC BIOS, in computing, stands for Basic Input/Output System or Basic Integrated Operating System. ... Phoenix AwardBIOS on a standard PC BIOS, in computing, stands for Basic Input/Output System or Basic Integrated Operating System. ...

Some microcontrollers, often those from before the era of EEPROMs and flash memory, use EPROM to store their program. This is useful for development, as using one-time programmable devices would be horribly wasteful for debugging. A microcontroller is a computer-on-a-chip optimised to control devices. ... A USB Flash Memory Device. ...

The EPROM was invented by engineer Dov Frohman. Invented the EPROM (Electrically eraseable programmable read only memory) ...

EPROMs come in several sizes both in physical packaging as well and storage capacity

NOTE: 1702 EPROMs were PMOS, 27x series EPROMs containing a C in the name are CMOS based, without the C are NMOS This article is about the unit of information. ... A byte is commonly used as a unit of storage measurement in computers, regardless of the type of data being stored. ... In mathematics and computer science, base-16, hexadecimal, or simply hex, is a numeral system with a radix or base of 16 usually written using the symbols 0–9 and A–F or a–f. ... A kibibit (a contraction of kilo binary bit) is a unit of information or computer storage, abbreviated Kibit, or sometimes Kib. ... According to the International Electrotechnical Commission a kibibyte (a contraction of kilo binary byte) is a unit of information or computer storage. ... A mebibit (a contraction of mega binary bit) is a unit of information or computer storage, abbreviated Mibit or sometimes Mib. ... Static CMOS Inverter CMOS (see-moss), which stands for complementary metal-oxide-semiconductor, is a major class of integrated circuits. ... nMOS logic uses n-type metal-oxide-semiconductor field effect transistors (MOSFETs) to implement logic gates and other digital circuits. ...

See also

• Programmable read-only memory
• EEPROM, like EPROM but electrically erasable
• Flash memory