|Re: Is there something going on out there? (or Getting Back to My Roots...)|
Message #23 Posted by Vieira, Luiz C. (Brazil) on 26 Apr 2010, 9:51 p.m.,
in response to message #21 by Martin Pinckney
Quote:I always applied the 'postfix notation' reference to the calculator core, I mean, math and arithmetic operations. If we consider algebraic notation, RPN is homogeneous in terms of math and arithmetic operations. In calculators operating with algebraic notation we have either postfixed (e.g.: 45 COS for COS(45), no need for [=] key) or infixed operation (e.g. 4 + 5 [=]) or, in some newer machines, prefixed operations (e.g.: [COS] 45 [=]; in these machines, COS( appears in the display when [COS] is pressed). Because algebric notation allows such distinctive keystroke sequences without loosing algebraic correspondence, chances are that RPN-based calculators have easier, simpler rules to be remembered.
(about RPN) the type of operation used by the certain traditional HP machines, which is really a combination of prefix and postfix.
All of the rest, namely structural operations like FIX, STO & RCL, program-addressed operations like LBL, GTO and GSB and others, are essentially prefixed in the early RPN models. With the HP67/97 the indexed -or indirect- addressing allowed prefixed operations to behave like postfixed operations.
But I guess all of this is mainly known, it is just a matter of putting things together. When the HP28C was introduced, two particular chapters in its Owner´s Manual deal with that: Notes for Algebraic Calculator Users and its counterpart for RPN, too. The softbound, thick HP48 Owner´s manual also brings a dedicated appendix: Comparing the HP 48 and HP 41. The PDF file in the link was created over scanned images of the original HP48 manual. Page #3 in this PDF (page #F6 in the original manual) has a very concise explanation about these differences.
Also, we must notice that Willian C. Wickes 'Insights' books are 'THE' source of information for these matters, if I may.
Well, I see I wrote too much, sorry! Chances are that users with the need of extra clarification may find in these texts some guidance. And I hope my writings will not get readers into confusion...
Edited: 26 Apr 2010, 10:00 p.m.