One thing I miss is RPN-string input. Unlike normal RPN where you load the "stack," for RPN string you can enter > 2 3 + 4 * as one line, press enter, and get

One thing I miss is RPN-string input. Unlike normal RPN where you load the "stack," for RPN string you can enter > 2 3 + 4 * as one line, press enter, and get 20. This lets you take advantage of the no-parens nature of RPN while viewing the expression on one line rather than flipping through the stack. Only Windows PowerToy scientific calculator had this mode, that I know of.