early digital image sensing / was Re: enough already...

[Rick Bensene]

This is on topic.

I have an old BYTE magazine that talks about the use of DRAMs with the
covers removed and a piece of glass placed over the chip, and using the
memory chip as an image sensor.  If I recall correctly, the first chip
used was an early Mostek MK5009.  They weren't great in terms of
resolution, but making multiple passes through reading, could gain a
couple of bits of grayscale resolution.  They needed pretty high light
levels, but served as usable image sensors.

Many years ago, I knew a guy that made a small business out of using
early 64Kx1 (256 x 256 array) DRAM chips, suitably modified, as image
sensors for PDP-11 based product inspection systems. 


-----Original Message-----
From: cctalk-bounces at classiccmp.org
[mailto:cctalk-bounces at classiccmp.org] On Behalf Of Brent Hilpert
Sent: Tuesday, May 29, 2007 9:23 PM
To: General at priv-edmwaa06.telusplanet.net; On-Topic and Off-Topic Posts
Subject: early digital image sensing / was Re: enough already...

Chuck Guzis wrote:
> 
> On 29 May 2007 at 17:27, Rick Bensene wrote:
> 
> > Motion seconded.  I can't see how anything related to digital
cameras
> > (except some of the very early video digitizing stuff) has anything
to
> > do with classic computing.
> 
> To put the subject back in the domain of "vintage"...
> 
> What outfit first sold digital cameras where the sensor consisted of
> a cermet-package DRAM with the chip cover replaced by a piece of
> glued-on glass?  Does anyone own one?
> 
> Cheers,
> Chuck

Don't know if this is the answer you're looking for, but it reminds me
of the
"Cyclops" camera: a peripheral for the computer hobbyist market,
contemporary
with the Altair/IMSAI . I assembled one for a friend who had an IMSAI in
1976
or 1977. I don't think we ever got it to work.

My recollection is that the sensor was a CCD array, but the occasional
mention
of these modified-DRAMs on the list leaves me wondering. I don't
remember what
the matrix size was: 256^2 seems too large, 16^2 seems too small,
perhaps 64^2.

I'm sure there must be adverts in Byte of the period. It would be a
pretty
rare find to come across one today.