The Museum of HP Calculators

HP Forum Archive 20

 RPN TutorialMessage #1 Posted by Eddie W. Shore on 25 Sept 2011, 1:49 a.m. In light of the HP 15C LE, it is my hope that there are new users of RPN calculators, either through the HP 15C, or by an Andriod (sp?) or iPhone/iPad app. This is a short "do by example" tutorial on basic RPN that I posted on my blog. It is not towards any specific calculator in hopes that newbies can learn from it whatever RPN machines/emulators they have. I am thinking of doing a basic keystroke programming tutorial (15C, 12C, or if anyone has a request, I'll try cater to that calculator instead - note my 41C is in repairs, I don't have a 42 (but I have Free42), and I don't have an Andriod device). Please check out the blog and me know what you think. Eddie Edited: 25 Sept 2011, 1:56 a.m.

 Re: RPN TutorialMessage #2 Posted by Xavier A. (Brazil) on 25 Sept 2011, 9:39 a.m.,in response to message #1 by Eddie W. Shore Hello Eddie, Nice. You may include this graph: RPN STACK PERMUTATIONS Regards.

 Re: RPN TutorialMessage #3 Posted by Dieter on 25 Sept 2011, 11:47 a.m.,in response to message #1 by Eddie W. Shore Hi Eddie, I think it's a good idea to familiarize others with the benefits of RPN. However, some errors should be removed: RPN uses one stack that consists of (usually) four registers X, Y, Z and T. Your text however says: "Typically, RPN calculators uses four stacks, named X, Y, Y, and Z." Instead, it should read: "Typically, RPN calculators use a stack consisting of four registers, named X, Y, Z, and T." So, X, Y, Z and T are four registers (not stacks), each register stacked on top of the other. That's why the whole arrangement is called a stack. Maybe an RPN novice will get the idea behind the stack more quickly if the examples show intermediate results. For instance like this (example #5): 2 [1/x] 0,5000 3 [ENTER] 7 [÷] 0,4286 [+] 0,9286 25 [ENTER] 64 [÷] 0,3906 [sqrt] 0,6250 ; use the symbol instead - there is no key labelled "sqrt" [-] 0,3036 ; do not omit the leading zero - it's displayed Re. Enter: about 30 years ago I had a book on RPN that described the idea behind the ENTER key in two-argument calculations this way: ENTER is required to tell the calculator that you have completed number entry. So 5 ENTER 3 enters two numbers five and three instead of a 53, thus separating the 5 from the 3. This also means that an ENTER is not required before or after a numeric operation, before or after a STO or RCL, before or after Pi, etc.: in all these cases it's clear that the current number resp. result is complete, and everything keyed in next will belong to a new number. So the first ENTER in your example #5 is obsolete since after 1/x the calculator knows that the result (1/2) is complete and the following 3 belongs to a new number. This idea was very helpful for me in the first weeks after I aquired my brand new 34C back then. Maybe you will find it useful as well. I really like the idea to help new RPN users the way you intended. That's why I suggest these improvements. :-) Dieter

 Re: RPN TutorialMessage #4 Posted by Eddie W. Shore on 26 Sept 2011, 1:34 a.m.,in response to message #3 by Dieter Thanks Dieter and Xaiver not only for the suggestions but also finding the errors. Xaiver, I want to study the diagram closer so I can understand it.

 Re: RPN TutorialMessage #5 Posted by Walter B on 26 Sept 2011, 1:54 a.m.,in response to message #4 by Eddie W. Shore Nice work :-) For the example with the square root of the sum of squares, however, I'd prefer 3 ENTER x 4 ENTER x + [sqrt] instead of using y^x.

 Re: RPN TutorialMessage #6 Posted by Marcus von Cube, Germany on 27 Sept 2011, 12:15 a.m.,in response to message #5 by Walter B ... which will not work on the 20b or 30b in RPN mode.

 Re: RPN TutorialMessage #7 Posted by Walter B on 27 Sept 2011, 1:50 a.m.,in response to message #6 by Marcus von Cube, Germany One more reason why I dislike RPL, also camouflaged.

 Re: RPN TutorialMessage #8 Posted by Eddie W. Shore on 27 Sept 2011, 9:34 a.m.,in response to message #7 by Walter B However, the above method (3 ENTER X etc...) works on the WP-34S.

 Re: RPN TutorialMessage #9 Posted by Walter B on 27 Sept 2011, 2:43 p.m.,in response to message #8 by Eddie W. Shore Since we did our best to make it RPN :-)

 Re: RPN TutorialMessage #10 Posted by Dieter on 27 Sept 2011, 11:11 a.m.,in response to message #5 by Walter B Eight keystrokes!!! That's way too complicated, Walter. ;-) In cases like these I usually type 3 ENTER 4 R-P or even 3 i 4 ABS Both suggested methods also provide better precision than a manual calculation. So this rectangular-polar conversion stuff (which I don't use at all otherwise) finally makes some sense to me. ;-) Dieter

 Re: RPN TutorialMessage #11 Posted by Walter B on 27 Sept 2011, 2:49 p.m.,in response to message #10 by Dieter You're right absolutely, Dieter :-) Please compare, however, also with the ten keystrokes in Eddie's original tutorial, take 2. After all, your solution is the best :-)

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