Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!gatech!bloom-beacon!eru!luth!sunic!mcsun!ukc!axion!galadriel!pcf
From: pcf@galadriel.bt.co.uk (Pete French)
Newsgroups: sci.electronics
Subject: Re: Batty monitors and cheap video
Message-ID: <371@galadriel.bt.co.uk>
Date: 2 Oct 89 09:47:13 GMT
References: <57732@psuecl.bitnet>
Distribution: sci.electronics
Organization: RT6115, BTRL, Martlesham Heath, England
Lines: 31

From article <57732@psuecl.bitnet>, by peg@psuecl.bitnet:
>> Now, regarding a cheap lo-rez video input, a mech eng friend of mine once
>> told me of this thing called a RAMera....
> 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.

No - they aint CCDS. CCDs are designer for use as a camera - and you cant
access each bit individualy like you can with RAM, you have to shift them
out serially. In low lighting conditions you can get bits lost in the shifting
which explains the smears accross the picture ou get from CCDs in bad light.

You dont have to open the DRAM yourself anyway - there is a company that makes
normal DRAMS with transparent lids. They are just standard production DRAMS
but can be used as cameras. They are a pain to use however since there are
odities like 50% of the bits are stored inverted and to get a picture you
have to jump about in memory since the bits are not stored linearly accross
the silicon.

This does give a useable picture - dont ask me how, but a friend of mine
interfaced one to a PC as a project and it worked for him.

-Pete.

-- 
       -Pete French.               | "I'm just a vision on your TV screen,
  British Telecom Research Labs.   |  Just something conjoured from a dream"
 Martlesham Heath, East Anglia.    |
All my own thoughts (of course)    |                       -SIOUXSIE.