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History behind importation of User Solutions to this site
Message #1 Posted by Les Wright on 3 Jan 2007, 5:09 a.m.

This question flows from my recent query regarding barcode reading.

In the process I have discovered that it would be far more reliable just to take the *.raw files I want from this site and convert them to barcode with the excellent Leo Duran utility.

I have started off my exploration with this code, originally from the HP41 High Level Math solution book:

16 Point Gaussian Quadrature for HP41

There is an interesting thing, though--the code (and associated *.raw file) on this site is very different from the original program listing in the High Level Math book (DVD owners can check it out). Since the use of the program involves the pre-storing of sixteen decimal constants (weights and sampling points), the re-rendering of the routine makes the supporting documentation wrong in this case, since it appears to me that in the rewrite register usage has been switched around. User key assignments given in the documentation are also irrelevant to the code as posted.

It will take me little time to look at the code and figure out the changes, so this isn't a criticism by any means. But I do have a question--when these User Library Solutions listings were imported to this site by Tony Duell et al., were they as a rule substantially rewritten, as this listing appears to have been? If so, for what purpose?--copyright? improved efficiency? And in the cases where big changes were made (indeed the Gaussian Quadrature routine is really a different program from the original), is there any altenate documentation to that refered to on the DVD?

I hope someone can confer wisdom upon me, as I am new around here and gather that there is a very good and probably well known story behind this. I have seen such differences before in some other listings, but this is the first time I have seen that the program posted is actually such a big departure from the published HP original. Since backengineering someone else's code does not come easy to me, I am always grateful for guidance.

There! and not a word about coburlin or high prices on eBay!

best,

Les

      
Re: History behind importation of User Solutions to this site
Message #2 Posted by Les Wright on 4 Jan 2007, 8:41 a.m.,
in response to message #1 by Les Wright

Just thought I would keep this thread active before it gets overtaken by other stuff.

Anybody have any idea about the observations/queries I offered in the original post? I guess the ultimate authority is Tony Duell himself, but I haven't seen him post lately.

Grateful, as always, for insight and wisdom of others who have gone before--

Les

Edited: 4 Jan 2007, 8:41 a.m.

            
Re: History behind importation of User Solutions to this site
Message #3 Posted by james summers on 4 Jan 2007, 3:16 p.m.,
in response to message #2 by Les Wright

Hi Les

I think that the version Tony posted is from the original High Level Maths User Solutions as it appears to be as listed in the book I have which although not dated is coded 00041-90083.

The version that is in the Museum's CD4 (and also the library on TOS) is coded 00041-90083 Rev D 11/82 and is titled HP-41 Users' Library Solutions. It has 83 pages and includes bar codes whereas my copy only has 63 pages and no bar codes and is titled HP-41C Users' Library Solutions. I'm guessing that at some stage someone must have submitted a more elegant version (or at least a slightly shorter version - 102 steps v 116 steps)

Best wishes

James

                  
Re: History behind importation of User Solutions to this site
Message #4 Posted by Les Wright on 4 Jan 2007, 4:34 p.m.,
in response to message #3 by james summers

Ah, so i have it backwards!

The code available in *.raw format is actually OLDER, not newer, from an earlier incarnation of the Solutions book.

This explains a lot. There are some differences in other programs too, sometimes a little more subtle, like the computation of the Gamma function which is the next program in the book.

Thank you for going to the trouble for looking that up for me. I must admit the explanation is not what I expected.

Les


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