I must confess to not being good at withstanding temptation; the second plot comes from another HP 7475A plotter that I won on eBay:
Apparently, nobody else wanted a plotter advertised as “non-working”, leaving me as the sole bidder. The photos showed that it powered up properly, sported a serial (not HPIB) interface, had an (empty) carousel with rubber pen boots (that were, oddly enough, not fossilized), and came with a complete set of manuals. Turns out any one of those items sells for more than the entire package, so I can part it out, flip the pieces, and Profit! if I were so inclined.
Load the carousel with a handful of restored pens, insert a sheet of paper, hold down the P1 + P2 buttons, flip the power switch, and out comes a perfectly drawn demo plot:
Compared with the first plot from the first plotter, I’m plotting like it’s 1989!
Which was the title of my Lightning Talk for the MHV LUG: MHVLUG – HP 7475A Demo – Plot Like Its 1989
Anyway, now I have a backup…