30 Jan
2009
30 Jan
'09
3:20 p.m.
I remember one article that described an incredibly
creative, low cost digital camera-like device.
Instead of a CCD, the thing used an ordinary DRAM chip with the cover pried off. The
light would
affect the cells of the DRAM, and then the 'image' could be read by the computer.
Of course, the
thing was incredibly primitive - the pictures weren't great, but it was an ingenous
hack, and a
clever utilization of the light-sensitive nature of these things.
This topic seems to come up here every few years...
In case anyone wants it, I have a scan of a two-part 1983 Circuit Cellar
artical called "Build the Micro D-CAM" which is essentally this, except
that he uses the IS32 "Optic RAM" from Micron.
I have the datasheet for the IS32 scanned as well, which says "Improved cost
standards for binary image sensing (less than $.0003 / element) are delivered
through Micron's MT4264 64K dynamic RAM memory chip as the sensing device.
The OpticRAM(tm) image sensor is differentiated by packaging with a glass lid
(vs the opaque lid used in memory chips) and connection of the normally unused
pin 1 for optical threshold reference adjustment".
So they actually state that they are using their standard 64k DRAM as the
sensor, but it's not clear how modified it is ... ie: what are they doing with
pin1 at the die?).
I've also got a scan of a 1975 Popular Electronics artical titled "Build CYCLOPS
first all solid-state TV camera for experimenters" - it's not clear what he used
for the sensor, he just referrs to it as a "1024 element MOS sensor" and
mentions
that it's packed in "a conventional 16 pin DIP". It's only a 32x32
display, and
he uses an oscilloscope for the display device...
Dave
--
dave09 (at) Dave Dunfield
dunfield (dot) Firmware development services & tools: www.dunfield.com
com Collector of vintage computing equipment:
http://www.classiccmp.org/dunfield/index.html