On Tue, Oct 13, 2015 at 11:25 AM, Paul Koning <[email protected]> wrote:
> There are all sorts of oddball printing technologies from back then.  I 
> remember
> one (from a lab instrument, not a printer or terminal) that used 
> aluminum-coated
> paper, but the coating was on the back of the paper.  The writing was done 
> with
> a high voltage electrode just as you describe, but the result was that the 
> sparks
> would scorch the paper and leave a thin black mark.

That reminds me of a printer I worked with in 1986 or so, but this one
had multi-layer paper that could be selectively burned for true
16-level grey-scale printing.  It was expensive, but the customer
needed to render ultrasonic scans in high fidelity, and even a laser
printers wouldn't work in this application because the sample
size/pixel size was too small for that to be effective.

These days, an inkjet printer could probably dither small enough black
dots to be a cost-effective alternative, or perhaps a 1200dpi laser
printer.

-ethan


>
> I don't remember what the VT55 used.  Tony's comment does sound plausible; I 
> distinctly remember "electrolytic" printing technology though no details.  I 
> wonder if it might help to take a bit of the paper to a competent chemist for 
> analysis, to find out what the active ingredient is.  That might help give a 
> clue what is needed to make it work.
>
>         paul
>
>

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