How do I learn RPL and solve this problem with it?

[Brad Barton]

(09-24-2017 12:48 PM)setq Wrote:  Any pointers appreciated. I explicitly don’t want hand holding, just a nudge in the right direction

If you want to learn RPL and how to use it to interact with the stack on the 50G, then the the 2 volumes by Bill Wickes are the go-to reference in my mind. The are titled "HP-48 Insights Part I" and "HP-48 Insights Part II" Both are available on the MoHP documents USB drive, which is available here http://www.hpmuseum.org/cd/cddesc.htm . This collection includes manuals for every HP calculator along with many useful documents. You may be able to find pdf's available on line as well. All example programs in the books can be downloaded from hpcalc.org http://www.hpcalc.org/details/8112

As a new user, you may not realize that the HP-50G is a grown up version of the HP-48, and the concepts that apply in the 48 will also apply in the 50G. The 50G has a larger command set, but the study of RPL implementations in the 48 will apply directly to what you'll need to program the 50G.

For a full explanation of the 50G command set you'll want to download a copy of the HP-50G Advanced User's Guide (AUR). It can be obtained at hpcalc.org http://www.hpcalc.org/details/7141

I find RPL a very useful language with many nuances. To make truly useful programs with it requires a bit of study, but it's very satisfying to craft an elegant solution to the problem at hand. A common complaint though is that it is difficult to debug or modify in the future, because keeping track of stack manipulations is an abstraction that requires effort to re-create in your mind once you've moved past the immediate problem.