Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!rutgers!uwm.edu!uakari.primate.wisc.edu!ginosko!brutus.cs.uiuc.edu!psuvax1!psuvm!psuecl!peg
From: peg@psuecl.bitnet
Newsgroups: sci.electronics
Subject: Re: Batty monitors and cheap video
Message-ID: <57732@psuecl.bitnet>
Date: 30 Sep 89 02:20:01 GMT
References: <1989Sep28.122217.26867@watcsc.waterloo.edu>
Distribution: sci.electronics
Organization: Engineering Computer Lab, Pennsylvania State University
Lines: 36

> Now, regarding a cheap lo-rez video input, a mech eng friend of mine once
> told me of this thing called a RAMera....

Yes, and you can see why he is an ME, can't you?  ;-)

> First of all, take a 4kX1 bit DRAM and somehow expose the silicon.  I suppsose
> you could pop the top of  an old ceramic or plane the top layer off a plastic.

Do you have a clean room handy? :-)

> To use the thing as a camera, just charge up the thing to all 1's, wait for a
> bit, and then check which bits are discharged by the ambient light.

Well, this actually works, in a manner of speaking.  The devices are called
CCD's, charged coupled devices, and are used for picture tubes in most
camcorders and video cameras.  As for making one from an actual RAM, I
seriously, seriously, seriously doubt that you can get ANYTHING useful by
opening up a RAM chip, but you are welcome to try.

If it helps, though, I recently saw single-dimension CCD's in a catalog.
These were strip type image sensing devices, that I think they use in
optical scanners (like the hand held scanners for computers) and in
optical character recognition devices.  The catalog was either Newark
or Allied Electronics.  I just looked for a while and  didn't find
them, but I know I didn't imagine them.  I seem to recall they were
fairly cheap ( < $100 ).  That might be something for you to fiddle
with, if you are interested in image sensing.

Also, I seem to recall that Don Lancaster spent some time discussing
these devices (as used in camcorders), their availability, etc.  Look
through back issues of Radio-Electronics, or get Don's address from
one and write him.  BTW, Don writes the Hardware Hacker column.

Well, good imaging!!

Paul