HP 9100A 50th Anniversary

[teenix]

(03-15-2018 12:31 PM)pier4r Wrote:  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.

I couldn't replicate the 3D image as I don't have the math, but it appears to be some sort of Bessel function.

I plotted a 2D slice of it though with the 9100B and plotter simulator using a file from the Model9125A Plotter Programs manual - Plot of Y = f(x), Part No. 09100-70027

It took about 50 seconds to plot.

cheers

Tony