Charlie wrote:
> "Michael J. Mahon"  wrote in message 
> news:9980d$492a52fd$29937{at}news.teranews.com...
> 
>>Charlie wrote:
>>
>>> wrote in message 
>>>news:ad98bdc8-a8ab-4434-b831-64a992cc4633{at}a37g2000pre.googlegroups.com...
>>>On Nov 14, 6:11 pm, "Michael J. Mahon"
 wrote:
>>>
>>>
>>>>Toinet wrote:
>>>>
>>>>
>>>>>Dear All,
>>>>
>>>>>I own a Microneye camera but I lack its software. I
would like to know
>>>>>whether some of you could provide me with a link to download it.
>>>>
>>>>>A search among the archive of csa2 brought me to
several threads and
>>>>>links but all return in error.
>>>>
>>>>>I thank you in advance for your help.
>>>>
>>>>Wasn't that the de-capped DRAM chip adapted for use as a camera
>>>>(from back when CCDs were very expensive)?
>>>>
>>>>Circuit Cellar (Byte Magazine) ran an article on it, IIRC, but
>>>>the principle should be:
>>>>
>>>>1. Write all 1's (or all 0's) to the DRAM,
>>>>2. Wait for the desired exposure time,
>>>>3. Read back the DRAM--any differences are proportional
>>>>to the received illumination.
>>>>
>>>>The relationship between address and the image geometry
>>>>will need to be determined empirically.
>>>>
>>>>-michael
>>>>
>>>>******** Note new website URL ********
>>>>
>>>>NadaNet and AppleCrate II for Apple II parallel computing!
>>>>Home page: http://home.comcast.net/~mjmahon/
>>>>
>>>>"The wastebasket is our most important design
>>>>tool--and it's seriously underused."
>>>
>>>
>>>| Yep, it's a de-capped RAM chip. Wouldn't there be a threshold per bit
>>>| - no "proportional"? Or maybe you could scan at
different exposure
>>>| times to assemble a gray scale image.
>>
>>This would be the natural way to proceed with a 1-bit threshold, but
>>it would take 2^n-1 exposures to get n bits, so anything beyond crude
>>grayscale would take a while.
>>
>>On the other hand, making multiple exposures and examining the
>>average number of 0's and 1's would allow for pretty good "automatic
>>exposure" adjustment by the software.
>>
>>
>>>| Does anyone know if capped non-Micron RAM chips also be used this way?
>>>| (I've got a box of "iffy" capped RAM chips)
>>>
>>>If I recall correctly, in the Circuit Cellar article a Micron RAM chip 
>>>was used because it was the only one that Steve found that had
the memory 
>>>cells laid out in a regular order 2 sets of 256 x 128 (Steve only used 
>>>one). Other chips at the time had the cells in different orders
such that 
>>>the position in the chip didn't correspond with the memory
address.  That 
>>>would have required a more complex program to put the pixels in the 
>>>correct order.
>>
>>True, and I can see how a "wirehead" like Steve Ciarcia would have
>>though that was a big deal.  But Apple II programmers know that *any*
>>permutation of bits in pixel addressing is a small matter of software
>>or tables.  ;-)  It would be almost as easy to use *any* DRAM in this
>>way.
>>
>>-michael
> 
> 
> Yes, I think you are right.  I asked Steve Ciarcia about the use of other 
> RAM chips shortly after his Circuit Cellar article appeared in Byte 
> Magazine.  At the time I had grandiose ideas of using several chips with 
> filters to make a color version of the camera but could not find a source 
> for the Micron chips at anywhere near the price of other makes.  We had a 
> long conversation on the subject but unfortunately my memory is not what it 
> used to be so I can't tell you any specifics.  I did however come away with 
> the impression that he thought it was too much trouble to use other chips. 
> By trouble I believe he meant not just the program to use the other chips 
> but also to determine where each cell was initially.  I believe he said that 
> each manufacture used a different pattern of cells some of which were very 
> illogical (at least when using the chip as an image sensor).
> I however, being more into software than hardware, thought that both 
> problems could be solved easily with software.
> I also thought it would be possible to use both sets of memory cells in the 
> Micron chip.  Steve didn't use both because there would be a 'dead zone' 
> between the two sets.  I figured that you could split the beam with prisms 
> or mirrors and merge the two images programmatically.
> Alas, my ideas got put on the back burner at the time and I never got back 
> to them.

With suitable beam splitting (with attenuation) it would be possible to
get two exposures at once, allowing for a crude (3-level) grayscale
capture in a single "shot"--or, with filtering, a 2-color rendition.
;-)

-michael

NadaNet and AppleCrate II: parallel computing for Apple II computers!
Home page: http://home.comcast.net/~mjmahon

"The wastebasket is our most important design
tool--and it's seriously underused."
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