fredtoo wrote:
sort of reminds me of the old computer-driven HP pen plotters we used for A/E drawings 30+ years ago. We would be 45 minutes into a drawing and one of the pens would run out of ink, or get plugged-up and you would have to trash it and start over. With those is was a matter of the paper moving N-S and the pens moving E-W. But they could create a perfect circle with that technique.
I hope they solved those kind of problems.
But its still amazing to watch.
Years ago, MANY years ago, at Sperry Univac I used an X-Y plotter connected to a sampling scope for recording signal waveforms that were used for ECL (Emitter Coupled Logic) signal analysis.