Useful HP-28 Links

[tcab]

I've just been having a great time exploring the RPN 28x Calc for iOS https://tredje.se/rpn28xcalc.html as it recently added programming support. I think the innovations it has added in the area of stack manipulation are worthy additions to the "philosophy" of stack based parameter manipulation and RPN computation.

For example you can select any item in the stack and the next operation takes its parameter from the selected item, not the top of the stack. I don't believe this has ever been done?

You can modify any item in the stack, drag to reorder items etc. It makes the stack much more friendly. Any future stack based calculators should look closely at this "state of the art" and incorporate similar features - IMO. Personally I've succumbed to algebraic notation most of the time, but if stacks ever came back into fashion, they would surely be more like this.