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HP Forum Archive 19

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HP50g Units Conversions
Message #1 Posted by Elliott W Jackson on 27 Mar 2009, 10:27 p.m.

I recently got an HP50g and have been plowing through the (shockingly bad) manuals. I was reading about the units capability, and stumbled on a trick I thought I would pass along.

TASK: Convert a value from one unit to another. Example: Convert 100 cm to yards.

Assuming Flag117 is set (Soft menus), and RPN, and assuming the UNITS menu is already displayed (Rightshift UNITS)

the method documented in the manual is as follows:


    100 Length "cm"
    0 (or any value, this value is not actually used) "yd"
    Next Next Next Units Tools Convert

That "Next Next Next Units Tools Convert" sequence is clumsy. Here is a much simpler method, relying on the calcutor's ability to add dissimilar units and do unit conversion as needed on the fly:


    100 Length "cm"
    0 (this time the zero is important) "yd"
    +

I'm sure the 50g old-timers knew this, but I found it useful when I stumbled onto it.

Best, Elliott

      
Re: HP50g Units Conversions
Message #2 Posted by Michael de Estrada on 27 Mar 2009, 10:53 p.m.,
in response to message #1 by Elliott W Jackson

Even easier, once you are in the length soft menu:

100 cm <Left Shift> yd

Michael

            
Re: HP50g Units Conversions
Message #3 Posted by Elliott W Jackson on 28 Mar 2009, 10:02 a.m.,
in response to message #2 by Michael de Estrada

Quote:
Even easier, once you are in the length soft menu:

100 cm <Left Shift> yd

Michael

!!

Now why in the world is that not documented?!?!?!?

Thanks for sharing, elliott

                  
Re: HP50g Units Conversions
Message #4 Posted by Michael de Estrada on 28 Mar 2009, 10:50 a.m.,
in response to message #3 by Elliott W Jackson

Elliott,

You have only scratched the surface of all the information that is NOT included in the documentation for the HP-50g. The only reason I knew this is because I also own a 19 year old HP-48SX, which has wonderfully complete and clear spiral-bound printed documentation. Ah, those were the days!

BTW - Additional information is contained in the Advanced User's Reference Manual for the HP-49g+/48gII from the hp website (see here) This information also applies to the HP-50g.

Michael

Edited: 28 Mar 2009, 5:49 p.m.

                        
Re: HP50g Units Conversions
Message #5 Posted by Peter Klein on 28 Mar 2009, 5:57 p.m.,
in response to message #4 by Michael de Estrada

Michael: How applicable is this 49g+ "Advanced User's Reference Manual" to the 48S? I downloaded it, and a lot of what I skimmed over looks like it would apply, with perhaps a few keystroke differences. And the PDF has searchable text.

Quote:
Elliott,

...I also own a 19 year old HP-48SX, which has wonderfully complete and clear spiral-bound printed documentation. Ah, those were the days!

BTW - Additional information is contained in the Advanced User's Reference Manual for the HP-49g+/48gII from the hp website (see here) This information also applies to the HP-50g.

Michael

                              
Re: HP50g Units Conversions
Message #6 Posted by Michael de Estrada on 28 Mar 2009, 6:37 p.m.,
in response to message #5 by Peter Klein

Peter,

All the commands, functions and reserved variables used in the HP48 are listed in the HP49g+ reference manual in section 3. Of course, many commands have been added, which do not apply to the HP48. Also, the HP48 lacks the CAS (computer algebra system) and the development library, so chapters 4 and 6 in the reference guide do not apply. One section I find especially useful is Appendix C, which lists and explains all the system flags. Only flags -1 through -64 apply to the HP48.

Michael

                              
Re: HP50g Units Conversions
Message #7 Posted by Egan Ford on 28 Mar 2009, 6:48 p.m.,
in response to message #5 by Peter Klein

Quote:
Michael: How applicable is this 49g+ "Advanced User's Reference Manual" to the 48S? I downloaded it, and a lot of what I skimmed over looks like it would apply, with perhaps a few keystroke differences. And the PDF has searchable text.
Why not just use the 48G Series AUR. It is probably closer to the 48S.

http://www.hpcalc.org/details.php?id=6036

                                    
Re: HP50g Units Conversions
Message #8 Posted by Michael de Estrada on 28 Mar 2009, 7:23 p.m.,
in response to message #7 by Egan Ford

It is a graphical scan, and does not have searchable text.

                                          
Re: HP50g Units Conversions
Message #9 Posted by Marcus von Cube, Germany on 29 Mar 2009, 5:39 a.m.,
in response to message #8 by Michael de Estrada

I found a HTML version of the hp48gaur on my hard disk. I don't know where it came from, so I've put a copy here:

http://www.mvcsys.de/temp/hp48gaur_html.zip

      
Re: HP50g Units Conversions
Message #10 Posted by Frank Rottgardt on 28 Mar 2009, 8:38 a.m.,
in response to message #1 by Elliott W Jackson

I donīt own any HP-50g but a 48gx. My first HP calculator was a 28s that has been of great help during my university years. In my opinion the unit coversion on the 28 series is more straight forward compared with the 48gx (50g?). The unshifted alpha keyboard is very useful when entering units. There is no need to plow through any menus, not even if one wants to convert rather complex&combined units that could be written as simple strings. Of course the 28s could not "calculate" with units. But I never thought this is a limitation. Generally I think the complexity of the 28s is already borderline and the 48 series was one (maybe two) steps to far in terms of intuitive use. With the 48gx I always feel somehow lost without the manual.

with the 28s (no menus needed):

100 "cm" "yd" convert

            
Re: HP50g Units Conversions
Message #11 Posted by Peter Klein on 28 Mar 2009, 5:06 p.m.,
in response to message #10 by Frank Rottgardt

Frank: I know what you mean about the 48 series' complexity. After years with RPN calculators (25, 11C, 32S, 32Sii), I just found a 48S on Craig's List for $30, and couldn't resist. I don't have a printed manual yet, and the Museum DVD's 48S/SX manual is graphics only (no searchable text), so the learning curve has been a bit steep.

But I remembered what a friend of mine who has a 48GX told me--"I can't remember how to do most things with it anymore, but it's worth having around just for the unit conversions). This thread came at exactly the right time to inform me about using the left shift key for conversion--thanks, Michael!

So now I can answer the age-old question: "If a train leaves Chicago at 6:00 AM traveling 50 mph, and a second train leaves New York at the same time, and they meet in Buffalo, what is the speed of the second train in furlongs per fortnight?"

--Peter

                  
Re: HP50g Units Conversions
Message #12 Posted by Chuck on 29 Mar 2009, 2:25 p.m.,
in response to message #11 by Peter Klein

Quote:
So now I can answer the age-old question: "If a train leaves Chicago at 6:00 AM traveling 50 mph, and a second train leaves New York at the same time, and they meet in Buffalo, what is the speed of the second train in furlongs per fortnight?"

Hmmm. Depending on which Buffalo, somewhere around 86,738 f/f possibly?

Someone had to. ;)

                        
Re: HP50g Units Conversions
Message #13 Posted by Jeff Kearns on 29 Mar 2009, 8:09 p.m.,
in response to message #12 by Chuck

I get 93,930 furlongs/fortnight.

                  
Re: HP50g Units Conversions
Message #14 Posted by Martin Pinckney on 29 Mar 2009, 5:39 p.m.,
in response to message #11 by Peter Klein

Quote:
Frank: I know what you mean about the 48 series' complexity... But I remembered what a friend of mine who has a 48GX told me--"I can't remember how to do most things with it anymore, but it's worth having around just for the unit conversions).

I am glad to know that others are willing to admit that they keep this extremely complex and capable device around for one function only... although I do use my 48sx occasionally for other tasks, using "canned" programs I downloaded...

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