HP 9100A 50th Anniversary

[pier4r]

Thanks to this thread I checked again the hp journal and I found some more issues about calculators that I did not read before. Especially about the 9100.

The hp journal is pretty nice.

One thing that captured my attention (journal 1969-09) was the following picture and explanation.

https://i.imgur.com/oyhIGN5.png




I was like "woah". I am pretty sure that some advanced computer system in 1969 could draw that picture (otherwise, well, it wouldn't be there). But was it done with 9100 with the plotter? Wow!

I am quite sure that the 9100 could compute the points of the function, but with so smooth curves? In other words, with such a resolution? (a lot of points computed, to achieve a very smooth curve on paper)

Furthermore, unless they let the 9100 process the values and then process them later with another system - and that would falsify the cover description - they even computed the 3D to 2D transformation that such surface would produce? (the isometric projection)

Would be someone able to replicate the 9100 program to get that picture or an approximation of it? (If not the 9100, a RPN calculator close to that model) It seems not that trivial.