Bye bye Prime

[Joe Horn]

(08-28-2014 11:27 PM)rprosperi Wrote:  I never thought about this way before, but Walter may have captured the essence of what is 'classic' RPN by adding 'top level replication and roll'.

Unfortunately, even that phrase is ambiguous; it doesn't distinguish between X-entry RPN and some recent 4-level entry line RPN models which also have top level replication and roll, e.g. the HP 20b and 30b in RPN mode. For example, in classic RPN, 1 ENTER 2 ENTER + yields 4, but it yields 3 on the HP 20b and 30b. Also, on the 20b and 30b, Clear stack, 5 ENTER CE (clear entry) 6 ENTER results in 0, 0, 0, 6 on the stack, whereas in classic RPN you'd get 0, 5, 6, 6. Huge difference. But they both have top level replication and roll. So that's not a defining difference.