Flash memory is the king of today. Our microcontroller embeds it in the chip. Mobile phones, tablets, and computers run through flash memory. If you need rewritable long-term storage, flash memory is the best choice. However, this has not always been the case. Just a few years ago, EPROM was the only fair in town. EPROM is usually burned in the programming fixture. When you need to erase the EPROM, just place it under an ultraviolet (UV) bulb for 30 minutes, and you can use it again. The quartz window of EPROM allows ultraviolet light to irradiate the silicon wafer and erase the memory.

When you want to use EPROM for long-term storage, problems arise. The EPROM eraser is not the only way to clear the chip. The sun will do this in a few weeks. Even fluorescent lights can do it-although this may take years.

[TechEkspert] wanted to understand the essence of erasing EPROM with the sun, so he took out an old EPROM and started hacking. (Translation link) [TechEkspert] programmed EPROM with known 1 and 0 patterns. A pair of 74HC4040 counters will address the entire 32 KB of EPROM memory. Arduino Mini reads the data and stores it in the SD card. Some Python code converts the data into PNG files and then combines them to render the video.

The entire installation is placed on a sunny roof. Then began to wait. Nothing happened for two weeks. Then some bits start to flash. This means that sometimes they will read as 0 and sometimes as 1. The sun began to destroy the stored data. At the 3rd week mark, all remaining data quickly started to disappear. Finally the entire chip is erased.

Although [TechEkspert's] chip can be reprogrammed, EEPROM and flash memory are not always the case. Check out this EEPROM killer, which counts the number of cycles required to destroy the electronically erasable storage in the Atmel ATmega328.

Heyyyyyyy, you can have a roof full of EPROM to generate RNG entropy from bit rot LOL

I bought one of them to erase some EPROMs. Work like a champion. It took about 8 minutes. https://www.amazon.com/GermGuardian-GG1000-Pluggable-Sanitizer-Reducer/dp/B000G2BESO/ref=sr_1_4_a_it?ie=UTF8&qid=1473852778&sr=8-4&keywords=uv+air+purifier

http://www.ebay.com/itm/New-High-Speed-110V-to-240V-UV-Light-Lamp-EPROM-Data-Eraser-Eraseable-Timer-/112111280074?hash=item1a1a5a5fca:g:1LEAAOSw65FXwiY2

I have this, it works fine, and it is done in a few minutes. It has a transparent tube, so it needs to be handled with care. Other things that can be used are nail polish dryers. They are also cheap and have a larger UV exposure area, so they are very suitable for making PCBs.

lmao gets an ultraviolet light strip. In addition to erasing EPROM, you can also put it in a PC case to let the smooth UV-reactive coolant glow.

Here I have some interesting website information (though not written by myself...) https://translate.google.co.jp/translate?sl=auto&tl=en&js=y&prev=_t&hl=en&ie=UTF-8&u=https% 3A% 2F%2Fvintagechips.wordpress.com%2F2016%2F05%2F11%2Feprom no elimination successfully%2F&edit-text=

Can it be blank for 15 hours? Is this normal time?

In my case, it only takes 5 seconds to erase, just like in this video...

By the way, it's this season... "Black Light" bulbs appeared in Halloween shops, and the price was quite cheap.

I'm afraid the effect is not good. You need UV-B or UV-C to erase EPROM.

I think they are UVb.. But the output is a bit low at 400nm, so it may take a while.

You need UV-B, just like a mercury arc quartz lamp, but the black light—as you said—is 400nm. This is at the boundary between visible light and UV-A. You don't want to-and don't-get sunburned by the dark light.

Usually, you need "hard" UV to erase EPROM. If light does not burn your skin and kill bacteria and other living cells, it lacks the energy to effectively erase EPROM.

Traditionally, a 254nm mercury fluorescent tube is used, but this is only because it is the cheapest and easiest thing to design in this UV stadium, not because the exact wavelength is special for EEPROM.

Ordinary nightclub black lights will not work. Anything with a mercury lamp, anything sold for sterilization, with warnings to protect the skin and eyes, should work well.

With the lens, you can start taking pictures. The earliest self-made/consumer computer digital cameras more or less relied on this effect.

Bad articles are bad, confuse DRAM with EEPROM.

Damn it, EPROM, my fingers stammered. EEPROM is different.

This is equivalent to watching the paint dry.

But microcontrollers are more patient than humans. :-)

I happened to find a Donkey Machine next to the trash can, so I grabbed it and put it in the warehouse. It needs work because I can clearly see that the CRT has a broken neck, so this is a minor project. After a few years, I finally understood. I realized that the sticker had fallen off the EPROM, and a small amount of direct sunlight in the storage area had wiped out all the data.

One of the early Bell Labs BLIT terminals had an overheating problem. (I forgot whether it was the 68000 or WE32000 version.) Someone at Murray Hill Lab implemented a standard solution for this, which was to cancel the backing for better cooling. But their desks are facing the windows (this building is old enough, all offices have working windows and beams for cooling.) A few weeks after the sun shines on the back of the terminal, the EPROM is erased and the terminal The machine forgot to become a terminal.

What is a donkey machine?

Think he meant Donkey Kong arcade.

I guess EPROM is not infinitely erasable (just like EEPROM and NAND/NOR flash). But because it takes 1,230,163 cycles to kill an EEPROM, and each cycle takes 3 weeks, I guess you can use it for nearly 500,000 years.

Damn it, learn to spell fluorescent correctly! This is not a damn cooking show! In addition, many years ago, before I got a suitable UV lamp, I had a technique for erasing EPROM. Has anyone used a carbon arc welding torch? They have two 45-degree carbon electrodes connected to an arc welding machine. The arc behaves like a high-temperature flame, and you can use it for brazing. Dirty hell, but relatively convenient if you don't have a gas supply. They also emit a lot of ultraviolet light-I found that at a distance of about 1 foot from the flashlight, about 5 seconds is enough to erase most EPROMs. Not exactly a laboratory technique, but you go ;-)

Haha, I bet it will work for me to put EPROM near the soldering station.

I am used to sunbathing for three days? Maybe it's altitude? (1700m above sea level) Different manufacturers?

Cover these tags or tapes on those chips and cover the devices outdoors or even in sunny windows and rooms! I just determined that 11 of the 12 of these 128k EPROMs were burned when lightning struck the organ. They are available, we have a second set to copy, and someone else is looking for it. They are waveform samples of the sound in the organ.

X-rays will also kill them... if the discharge is large enough.

In the early days of IBM PC cloning, motherboards with unlabeled EPROM would crash when photographers took flash photos. Enough time happened at the trade show.

Not long ago, Rapsberry Pi also exhibited such behavior. The culprit is the voltage regulator in the CSP (almost bare chip flip chip).

interesting! ! ! When I couldn't afford my own UV eraser in the 90s, I tried drying for a few hours, but gave up and borrowed an eraser. The mystery is finally solved :)

I used an old UV sun lamp and I converted it to PCB exposure. I have removed the infrared heating element, which is also used as a mercury lamp ballast, and replaced it with two parallel 60W fluorescent tube chokes. Because it emits enough ozone smell when turned on, I would rather leave the room than deliberately expose my skin to radiation-this is the original purpose of this lamp.

Can we add some lenses and make the slowest digital camera in the world?

Daisy chain a bunch of power and ground pins on the board. Solar energy! :) (very small amount of solar energy...)

If the EPROM is all erased, why is the pattern not all yellow or all red, but two colors? What is the ribbon about 1/3 down?

It is like a diffraction grating, or look at the reflection of a CD. Iridescent.

No, he was talking about video. It uses red and yellow in the EPROM data chart. I am not sure about it myself.

What is the best USB programmer compatible with these EPROMs available today? I have an old Willem 3.1 parallel port programmer, and it can read them, but never managed to get it to write them correctly.

Thwy used to have a write pin that required a high voltage, such as 15-20V. No programmer is used, just a parallel printer port and a string of 1.5v batteries with a switch to enable writing.

I find it surprising that it takes two weeks before any bit flips.

Thirty-five years ago, we used chips such as the 2716 UV-EPROM chip. Under direct sunlight, on a cloudless day, on the roof of the campus EE building, we regularly erase them within 20 to 30 minutes. . We often did this for several months before we received a laboratory eraser based on a germicidal UV lamp. The germicidal lamp usually also takes 30 minutes.

The technique is basically the same as 27256 (in the article), so I am confused about the two-week sunlight conditions described in the article.

First of all, it is energized, which I think may add an additional energy barrier to overcome.

Secondly, I wonder if they didn't put it in the bag, because exposing the solderless breadboard to the element for 2 weeks doesn't seem to be something you would do. Then we want to know how well plastics can block UV rays.

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