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My TI 36X pro recently died so I started researching a new calculator when I came across the HP style RPN, that’s where I am now at the Swissmicro line of calculator. I am a field engineer for a heavy civil company so am looking for a general day to day calculator for finding dimensions, volume etc. I have never used a calculator for DMS but do either the DM41X or DM42 have a DMS feature? For my use what would y’all recommend between the two? Thanks[/code][/php]

Just quick clarification when I say DMS I am referring to degrees minutes seconds, my fault for not including this from the start.
I would say that a person for no prior experience of HP rpn machines, go with DM42. The is no algebraic entry at all (41 or 42) everything is done with postfix operations:
1 1 + is the same as 1 + 1

That said there might be full professional module for HP41 and DM41 for your field of engineering.

You can try out Free42 from Thomas Okken in your phone to evaluate if you like it or not. Dm42 from Swiss Micros is actually a physical device running Free42.

What do acronym DMS stand for?

DM41 and HP41xx are more "hackable" and it is more like a microcontroller in a box (a hobby project with endles modules etc. what I have understood, a fine machine especially for those who have prior experience of HP41xx).
(04-04-2021 09:20 PM)rjl2015 Wrote: [ -> ]I have never used a calculator for DMS but do either the DM41X or DM42 have a DMS feature? For my use what would y’all recommend between the two?

In case you mean Degrees, Minutes, and Seconds: the DM41X and DM42 both have the same set of functions for working with times and angles in that format. HR and HMS (DM41X) or →HR and →HMS (DM42) for converting between Hours (or Degrees), minutes, and seconds, and decimal hours (or degrees), and HMS+ and HMS- for adding and subtracting hours/degrees, minutes, and seconds.
Of the models you have listed I would recommend the DM42 for its speed, precision (34 digits!) and support for solve, integrate, complex numbers and matrices. There are a seemingly endless number of modules available for the DM41X but utilizing them can be difficult for those who are not familiar with the HP-41. Also accuracy is limited to 10 digits.

If you use unit conversion in your work, the HP48/HP50 are unbeatable. They also handle complex numbers and matrices in a more intuitive way. However it is hard to find an HP48 or HP50 at a reasonable price.
(04-04-2021 11:22 PM)Thomas Okken Wrote: [ -> ]In case you mean Degrees, Minutes, and Seconds: the DM41X and DM42 both have the same set of functions for working with times and angles in that format. HR and HMS (DM41X) or →HR and →HMS (DM42) for converting between Hours (or Degrees), minutes, and seconds, and decimal hours (or degrees), and HMS+ and HMS- for adding and subtracting hours/degrees, minutes, and seconds.

And the SM44 [SandMath] module, for the 41, adds HMS*; there's no need for an HMS/, since that may easily be done with 1/x and HMS*, to save module space.
I will be the heretic and suggest a Casio. Many of their scientific calculators have a dedicated DMS (° ' ") key right on the keyboard allowing you to enter values and calculate with them directly with no other conversion steps or special HMS+ functions required.

DMS calculations on the fx-991EX are far more convenient than on the TI-36X Pro, which requires you to dig into a menu to enter the DMS symbols. On a Casio, you can do something like entering 6°25°30°×9°21°18° using the [° ' "] key to denote degrees, minutes, and seconds, and get a result of 60.105875, then press the DMS key once more to convert to 60°6'21.15".

You might also consider getting the fx-5800P, though you'll have to import one if you're in the US. It's programmable, has 32 KB RAM, a dedicated DMS key, and Casio's engineering symbol display/entry mode.
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