OpticRam

[Terry King]

At 06:08 AM 1/29/2006 -0600, you wrote:
>Ayone else remember the 'Optic RaM', a poor-man's image sensor.
>
> >From what I remember they were a normal DRAM chip with a quartz lid to
>the package (it's been suggested you could take a cerdip 4116 or 4164,
>knock off the top and replkce it with a window).
>
>The idea was you focussed an image onto the chip. Stored 1's in all
>locations, waited a bit and read out the contents. Those cells which had
>been exposed to enough light would read out as 0's. Do it again with
>different waiting times (note, once you've read out a pattern, you've
>lost the charge stored in the cells, you have to start again, you can't
>read the chip repeatedly without filling it with 1's), combine the
>resulting bit patterns to get a sort-of grey scale image.

I designed some instant-display chip-fail display systems years ago.  We 
were probing
full wafers of chips.  First thing I saw, first image that worked, was a 
image of the
probes reaching in from all sides, to the chip.  We forgot to turn off the 
microscope illuminator, which was BRIGHT!

Guys got into scratching their initials on a chip, and saving the bitmap...




Regards, Terry King  ...On The Mediterranean in Carthage, Tunisia
terry at terryking.us