Hi,
your experiment was unsuccessfull, because of normal window glasses filter
the UV component out. That's why EPROM's have special quartz window. A
direct exposure can tamper the EPROM's content in less than one hour I
guess (at least at us, in a Summer Noon).

Regards,
Imre


On Thu, 23 Sep 1999, Keelan Lightfoot wrote:

> >Is it possible to erase a windowed PIC with sun light ??
> >How much do I have to wait ?
> >Bye and thanks
>
> Yes, it is possible. For EPROMs (27xxx series), some datasheets state that
> erasure in the sun requires 1 week of constant direct exposure. I left a AMD
> 2732 EPROM in a south facing window for 2 months, and nothing changed. An
> intel datasheet says "constant exposure to room level fluorescent lighting
> could erase the EPROM in approximately 3 years."
>
> I finally broke down and bought a $150 canadian EPROM eraser, that can eat
> about 20 EPROMs at a time, meaning about 80 8 pin PICs at a time.
>
> If you are looking for alternative erasure methods, have a look at:
> http://www.intermarket.net/~don/uvbulb.html
>
> - Keelan Lightfoot
>
>