So I bought an HP 7475A RS232C plotter at a yard sale with a box of 're-inked' pens. To my pleasant surprise it worked and drew a nice ANSI A plot when powered on in demonstration mode.

Then I connected it to my Windows 10 Professional PC with a USB to RS232 converter. The interface device showed up in Device Manager but my DraftSight 2017 Professional doesn't see the plotter. 

Is there any hope that a DraftSight compatible driver is somewhere in the cloud? I know it's an ancient instrument but then I am too. I thought it would be fun to show my son how we generated drawings before there were even cell phones. :-)

Did I just waste \\\$20?