Can we have RPN back?

[John R. Graham]

Thanks for taking the time to explain. The first HP calculator I laid my fingers on was one of the 9100 series (3-level stack; it was my father's and I must've been about 10). I've since used the 35, 67, 97, 41 series, and 48 – 50 series.

Although I definitely took advantage of the shortcuts that automatic stack lift enabled (e.g., "number [ENTER] [x]" for \(x^2\)), I think the version of RPN as exemplified by the 28 – 50 series is definitely my favorite. (Han has convinced me that this should be called Entry RPN.) I've certainly been using it the longest.

- John