31 Jan
2009
31 Jan
'09
5:34 p.m.
Dave,
The Cyclops you mentioned below ( from 1975 ) used a MOSTEK 4008 with an
Optical window. There is a guy still selling them for a " mere " $35 if you
are so inclined.
You cannot just use a standard 64K DRAM chip for an imager because the cells
are not necessarily contiguous ( because of yield problems there is
redundancy and sections are added or subtracted to yield a usable device ).
They're also usually built into at least two 32K sections.
Best regards, Steven
cost
> 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 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