Courtesy of Jason Foose, the Mohave County Arizona County Surveyor: "I found these in a dusty corner of our facility. Click on any particular issue to view. It will pop up with a blue “open” button on the lower right and page thumbnails on the left after you hit open."
https://drive.google.com/folderview?id=0Byv79l1-tINAemtZM1Njek1VWU0#
These issues of HP’s Insight publication span the time from 1972 to 1976, and are pre-3820, HP85 and 7500 series carousel pen plotters. I fondly remember the daisy-wheel 9871 printer shown in Vol4No1. We used the heck out of that because it was a mini-plotter.
I have written a lot about my experiences with Hewlett Packard, most notably here: http://www.profsurv.com/magazine/pdf/archives/xyzworks_200302.pdf
Everything you ever wanted to know about the 3820 can be found in an 8Mb PDF here: https://amerisurv.com/docs/HewlettPackardJournal.pdf. Truly an instrument way ahead of its time, some of its technology has never been duplicated, and it wasn’t until Roger Höglund (from Geodimeter and then Trimble) introduced the S6 total station that the idea of bouncing a light to determine level was duplicated. The 3820 used a quarter ounce of liquid mercury covered with an optical flat, but because mercury is hazardous the new instruments use a pool of liquid silicone. Figure 9 in this PDF shows how the unique tilt sensor worked.
There’s a picture and explanation of the S6 level-sensing apparatus on the last page in this article: https://amerisurv.com/PDF/TheAmericanSurveyor_Cheves-TrimbleSweden_November2007.pdf
and more about the S6 here: https://amerisurv.com/PDF/TheAmericanSurveyor_EditorsCorner_March-April2005.pdf