If it doesn't have an Enter key, it's not RPN

[MarkHaysHarris777]

(02-05-2015 08:25 PM)Michael de Estrada Wrote:  Every single one of my many non-HP RPN calculators have some sort of Enter key on them, although I do know of a few exceptions such as the National Semiconductor NS600.

RPN really does not have anything to do with whether the calculator has an equals key (strictly speaking); it is only really about whether the operator is 'postfix' or not. By definition, all ten-key adding machines are RPN. My wife is an accountant in the States, and we have several ten-key machines around the house. The classic TI5630, and the TI5033, are two examples worthy of note; and both have an equals key.... but, no one (accountants) ever press it! Those two machines have ONE very large key marked with a plus (+) which is strictly a 'postfix' operator (the minus operator works the same way). She will fly over that little box(s) clicking away at some gigantic list of tax receipts (or the credit card statement) and NEVER presses the equals key (not ever).
The other key she uses heavily is the (* T) key which is equivalent to the CLSTK function on the WP34s. The running totals (all postfix) need a grandtotal|clear in order to begin adding the next gigantic column of numbers (sometimes for the 11th zillionth time, just looking for that lost penny) Is that like a farthing six-pence in the U.K? <sorry random>
Well, there is a reason they are called 'adding machines,' at least here State-side. As it happens, she can multiply on her 'adding machines' (with the equals key) but she doesn't ever do it!
In fact, I was showing her the WP34s (bragging about not killing it with my soldering iron) and explaining the whole RPN thing thinking she wouldn't get it... she said something like, "of course, how else would you add on a calculator?" "... how come your (+) plus key is soooo small?" "... why didn't they call that big ENTER key over there the (+) plus key and put it down there on the lower right where it belongs?"
Some people's accountants! :-}

HP was not the first to build a calculator with RPN (although they are the ones to make RPN famous). Very honestly I think the quirks of the HP four level stack make the machines more famous than RPN, frankly. But certainly they go together. Adding machines do not have a stack (nor do they need one). Adding machines don't need to multiply or divide either (although just because its easy to make an adding machine into a four-banger, they do) and most people who 'need' an adding machine because they pound their large postfix (+) key all day long could care less whether their adding machine multiplies or not, let alone whether the * and / are postfix or not.

I say, RPN is as RPN does. RPN is in the eye of the beholder.

cheers,