I developed a familiy tree for the machines and I would like to share the idea with our friends in The Museum. The
diagram was prepared based on the one available in Craig Finseth's site with added information taken from The Journal and other sources. There is a lot of personal opinion, like the idea that the whole thing started with
the HP-35 model. You can see it at:
http://www.hpmuseum.org/guest/goncalv/hptree.pdf
As for the "instantaneous" development suggested by the vertical lines, they are mostly due to HP company information that some models were released in the first months of a certain year while some other models were available only later in the same year. They also represent models that belong in the same group of development, as far as the available information is concerned.
Anyway, I think the diagram shows very clearly the impetus that once drove HP company which is one of the reasons why we are so deeply involved with their products. Hence the big title I gave the diagram.
I'm trying to improve the vertical dimension as to make the diagram more complete and easy to understand.