Archival storage

[Brent Hilpert]

Chuck Guzis wrote:
> 
> Back when small printers were hard to come by, there was at least one technology
> that used a "paper' made of a black layer on a paper substrate covered by a very
> thin layer of aluminum.  The printer burned through the aluminum, leaving the black
> spots exposed.  Oddly enough, this sounds like a fiarly permanent process.  Was the
> stuff called "electrographic" paper?

The Canon EP151 calculator used this technique as early as 1971.
A rotating stylus is fed with 120 VDC driven by the output of an
early MOS character generator ROM.

Even earlier though: Western-Union/Seeburg TeleFax FAX machines circa 1960 used
the technique. The paper is placed on a rotating drum for scanning and output.
The output paper is similar to carbon paper with an additional aluminised coating
or an aluminum-carbon amalgam.
All tubes. Signal is analog, mechanically chopped for Pulse-Amplitude-Modulation
transmission over the telcom line.
(.. got two of them, but they don't work simply connected back-to-back, have to
figure out what was in the 'cloud' in between, someday.)