On 8/4/2010 8:09 AM, Mike Harrison wrote:
>
> ISTR that you could reliably crash a system running from EPROM by firing =
a flashgun nearby - I think
> light messes up the read amplifier thresholds.
>

Absolutely.

Light into eprom windows can and usually does affect the operation.  I=20
have seen A/D counts vary when light shines into the window.

And once had a system fail in a spectacular fashion from a camera flash=20
going off.  In a development environment, the windows are usually left=20
open ready for another trip through the uv eraser.  A windowed PIC was=20
driving some fets for motor control.  The customer came to see how=20
things were going and whipped out a camera and snapped a photo. Bang!=20
All fets were turned on at once and shorted the nicad battery pack=20
blowing out the fets.

In a related area, early video camera elements were made from DRAMs with=20
out covers over the chips.
--=20
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