HP 7475A Plotter: Pen Performance and a Backup

By now, I have half a dozen baggies each containing half a dozen plotter pens, plus a demo program that can produce good-looking Superformula plots, so I can do this without any hassle:

HP 7475A 2541A 68465 - Random pens

HP 7475A 2541A 68465 – Random pens

And this:

HP 7475A 2641V 26599 - Random pens

HP 7475A 2641V 26599 – Random pens

I must confess to not being good at withstanding temptation; the second plot comes from another HP 7475A plotter that I won on eBay:

Stacked HP 7475A Plotters

Stacked HP 7475A Plotters

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:

HP 7475A 2641V 26588 - Firmware Demo Plot

HP 7475A 2641V 26588 – Firmware 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…


  1. #1 by Andrew on 2015-09-12 - 07:35


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