VT52s, VT61s lots of DEC and DG keyboards- return trip through Maine, MA, NY, PA, OH, IN to IL

[tony duell]

>
> Paul, if you come across any VT52s that have the built-in screen
> printer could you take some pictures please.
> 
> Has anyone ever seen one? I had an idea it used a silvered-paper and
> burned it off? or am I mis-remembering.

I have one. Well, in a VT55, but that is a VT52 with a graph-plotting board, so
I guess it counts :-)

It appears to be electrolytic. You have to keep the paper damp (there is a wick
inside that you put water on. The paper goes between a helical electrode on
a spinning drum and a straight strip, the latter being replaced when you fit a new
roll of paper. Whether it is some chemical in the paper that changes colour, or metal
depositied from the electrode I don't know (the former seems more likely). 

I have never got it to work. Whether that is due to electronic problems (that I can
fix) or chemical problems with the old paper (which I can't) I don't yet know.

-tony