1 Jun
2000
1 Jun
'00
9:38 a.m.
2. About 1982 I started hearing that it was possible
to
build a camera for your pc by "cooking" an EPROM under
UV light for an extended period until the memory cells
were still light sensitive but would no long hold a
charge. Then by placing a len over the EPROM's window,
you had a real time low-res video image mapped right into
memory. Again this is one that quite a few people had
heard about but no one knew anyone that had ever done it.
I don't think that would work. I've cooked EPROMs for months
without any change in their functioning.
More likely, you could marginally program all the bits, or program
them solidly then erase until they're marginal. Then outside light
would move them across the threshold. However, this would be
*extremely* sensitive to temperature and supply voltage. I doubt
it could be made even slightly practical.
On the other hand, if you pop the top off an old DRAM (made before
they started adding opaque passivation layers), they make a
servicable imaging element, if you don't mind the gaps between the
quadrants (which would also be found in EPROMs). There were actually
some products that used this technique, and Micron sold DRAMs packaged
for this purpose.