HP EXL 7575A plotter and Winplot under ExpertCAD 1

There are sometimes conflicting standards for these settings.
You can get info from HP themselves on the pinouts and handshaking they think will work. Remember that this may be old data based on older computer operating systems.
Then you must read what your CAD program says will work.
Then you must also check the default settings for your particular OS.
If these are all different (as they often are, in my experience) then you have to use trial and error. Make up different cables and try each with different software settings.

I've made a cable according to both the User's Manual and HP website info. I does communicate with the plotter and some of the test plot features are plotted correctly, but not all features do so. I suspect the driver supplied with ExpertCAD is not complete or is inaccurate. With this in mind I'm looking at the "WinPlot .txt" file and trying to understand what is what and if it is all there. At present I do not see a relation between the codes given in the manual and the codes listed in other sources, futher readings may solve this. I seem to come across something new every few days.

One issue is the plotter is marked as a DraftPro EXL and according to current understanding it should be a 7575 or 7576 the name tag on the back side is stamped 7575A. WinPlot list only plotters with lower numbers (closest 7550) and Higher numbers (next closest7580), with an series of drivers listed as "7570 draftpro plotter" and these are the ones I comparing for analysis.

I'm hoping to find someone who has been thru all this and cut to the quick.

Thanks Mark