> > > I had a little Comprint printer in the 1970s/1980s that used something > sort of like this. The paper was aluminum coated, thus conductive. The > head was a high voltage electrode unit that burned away the aluminum > layer. (I can't imagine any kind of deposition technology in that > era...). The head flew back and forth really fast, doing one pixel-line > at a time.
That is how the Sinclair ZX printer works and also things like the Axiom EX820. Spark (about 80-100V IIRC) to aluminium-coated paper. The VT52 printer is not like that. The raw paper looks like paper (slightly yellow, but that might just be age), it is not metal-coated. Another odd one is the Olivetti JP101 Sparkjet which drew a spark (a few hundred volts?) from a carbon electrode to a fixed metal one and in the process got some of the carbon flying across the gap and landing on the paper just above the metal electrode. The result was poor quality output that smudged if you looked at it wrongly... -tony
