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HP-35A/21 D.MS<-->Decimal degrees routines
Message #1 Posted by Matt Agajanian on 28 Mar 2012, 8:50 p.m.

Hello all,

In that the HP-21 (Woodstock) and HP-35 (Classic) do not have conversions to and from degrees to degrees/minutes/seconds, has anyone devised a method to convert the decimal degree value to degrees-minutes-seconds? Please let me know.

Thanks

Edited: 28 Mar 2012, 8:50 p.m.

      
Re: HP-35A/21 D.MS<-->Decimal degrees routines
Message #2 Posted by Eric Smith on 28 Mar 2012, 9:02 p.m.,
in response to message #1 by Matt Agajanian

Not anything automatic. You can obviously do it by working through the calculations manually.

      
Re: HP-35A/21 D.MS<-->Decimal degrees routines
Message #3 Posted by Gerson W. Barbosa on 28 Mar 2012, 10:15 p.m.,
in response to message #1 by Matt Agajanian

From Hewlett-Packard's HP-35 MATH PAC, available in the HP Museum DVD 1, Calculator Manuals:

Degrees, minutes and seconds to decimal degrees

LINE	DATA	OPERATIONS		DISPLAY		REMARKS
 1    Seconds	ENTER^ 6 0 STO /
 2    Minutes   + RCL /
 3    Degrees   +

Example 

      32.6      ENTER^ 6 0 STO /     .5433333333
       17       + RCL /              .2923888888
       46       +                    46.29238889       46°17'32.6" = 46.29°

  
Decimal degrees to degrees, minutes and seconds

LINE	DATA	OPERATIONS		DISPLAY		REMARKS
 1       X	ENTER^                                  Let D = integer part of X
 2       D                              Degrees
 3              - 6 0 STO *                A            Let M = integer part of A
 4       M                              Minutes
 5              - RCL *                    B            Let S = nearest integer to B
 6       S                              Seconds

 
Example   

  23.32916667	ENTER^                  23.32916667                 
       23                               23.             Degrees (integer part of X)
               - 6 0 STO *              19.7500002      
       19                               19.             Minutes (integer part of X)
               - RCL *                  45.000012       
       45                               45              Seconds (nearest integer to X)
                                                        23.32916667° = 23°19'45"

            
Re: HP-35A/21 D.MS<-->Decimal degrees routines
Message #4 Posted by Paul Dale on 28 Mar 2012, 10:54 p.m.,
in response to message #3 by Gerson W. Barbosa

Quote:
LINE	DATA	OPERATIONS		DISPLAY		REMARKS
 1    Seconds	ENTER^ 6 0 STO /
 2    Minutes   + RCL /
 3    Degrees   +

Interesting, using the single storage register and saving no keystrokes in doing so....

Likewise for the reverse conversion.

- Pauli

Edited: 28 Mar 2012, 10:54 p.m.

                  
Re: HP-35A/21 D.MS<-->Decimal degrees routines
Message #5 Posted by Gerson W. Barbosa on 29 Mar 2012, 7:39 a.m.,
in response to message #4 by Paul Dale

Quote:
Interesting, using the single storage register and saving no keystrokes in doing so....

...unless more than one conversion is performed, but then the instructions should be updated:

LINE	DATA	OPERATIONS		DISPLAY		REMARKS
 1    Seconds	ENTER^ 6 0 STO /                        for the second and subsequent conversions
                                                        execute the following operations instead:   
                                                        ENTER^ RCL /                                
 2    Minutes   + RCL /   
 3    Degrees   +

Gerson.

Edited: 29 Mar 2012, 7:52 a.m.

                        
Re: HP-35A/21 D.MS<-->Decimal degrees routines
Message #6 Posted by Marcus von Cube, Germany on 29 Mar 2012, 9:52 a.m.,
in response to message #5 by Gerson W. Barbosa

RCL should make ENTER^ superfluous.

                              
Re: HP-35A/21 D.MS<-->Decimal degrees routines
Message #7 Posted by Gerson W. Barbosa on 29 Mar 2012, 2:05 p.m.,
in response to message #6 by Marcus von Cube, Germany

Right you are! This means more keystroke saving on multiple conversions. I guess surveyors appreciated the successor of the HP-35, the HP-45, when it was released.
Still not programmable, but it had ->D.MS and D.MS-> built-in :-)
Also, a nice feature: no matter the current display mode, ->D.MS would leave the calculator temporarily in FIX 4 mode.

Edited: 29 Mar 2012, 2:12 p.m.

      
Re: HP-35A/21 D.MS<-->Decimal degrees routines
Message #8 Posted by dbatiz on 29 Mar 2012, 1:47 a.m.,
in response to message #1 by Matt Agajanian

There was a tread not too long ago where somebody posted equations that accomplish this. He made his posting as a guessing game, something about "Try to identify these" or something like that. I did a quick search, but came up empty handed. Does this ring any bells?

Very respectfully,

David

            
Re: HP-35A/21 D.MS<-->Decimal degrees routines
Message #9 Posted by Gerson W. Barbosa on 29 Mar 2012, 7:17 a.m.,
in response to message #8 by dbatiz

Here it is:

Do you know these 2 functions ?

Regards,

Gerson.

      
Re: HP-35A/21 D.MS<-->Decimal degrees routines
Message #10 Posted by Matt Agajanian on 29 Mar 2012, 11:03 a.m.,
in response to message #1 by Matt Agajanian

Hello all. Fantastic job on the D.MS<-->D.DDD conversion routines. I tried developing some algorithms last night. In comparison, yours were quite streamlined.

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