Algorithm for entering numbers?

[Thomas Okken]

(08-12-2019 08:34 AM)Ángel Martin Wrote:  BTW I did a check on Free42 and it appears to follow your option, so you're in good company as supposedly that's also how HP did it on the original HP-42S, is it correct?
And on the DM-42 by extension it should also behave the same way... does it?

RCL arithmetic behaves like unary functions: no stack lift or drop, and the old contents of X are preserved in LASTX. Even if Free42 wasn't written to be compatible with the HP-42S, I'd still have implemented those functions that way, because it's logically consistent *and* more useful than the alternative, as grsbanks pointed out. If you want the semantics of RCL nn +, just do RCL nn +, not RCL+ nn.