DM42 (SwissMicros) - Solving Various Engineering Problems
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- čas přidán 4. 07. 2024
- Using the DM42 to solve the same sorts of engineering problems that I previously solved using the HP48GX and the HP Prime (czcams.com/users/playlist?list....
To learn more about the DM42 and all kinds of other calculators you can have a look around my channel, but be sure to also check out Logan West's channel: / loganswest
Here's what is covered in this video:
- Solve an equation for x [1:07]
- Solve a multi-variable equation for a specified variable [2:56]
- Solve a system of simultaneous equations [6:41]
- Given f(x), find f(7) [7:51]
- Find the resultant of three 2D vectors [9:35]
- Degrees-Minutes-Seconds (DMS) to Decimal Degrees (and vice versa) [11:21]
- Converting Rectangular to Polar Coordinates [12:33]
- Miscellaneous other problems [14:54]
Whoah, I was intrigued to see a DM42 video recommended, I didn't realize I'd get mentioned in it. Nice video!
Thanks! Yes, I have definitely watched my fair share of your videos. Thanks for leaving a comment and for the good content you have shared on your channel.
Forgot to mention; the idea to preface solver programs with a dot is very clever! I immediately adopted that convention as well.
I recently purchased a DM42 and this video was helpful in learning how to use it - thank you.
Glad you found it helpful. Thanks for letting me know. Enjoy your DM42 -- it's a cool little calculator.
Great video/reminder on how to solve different problems with the DM42… Thanks Scott!
Appreciate you leaving a comment - glad you found it helpful. Take care, Scanito.
Just got my DM42 and am learning lots of cool little things about it which have just been done very thoughtfully. For example, for your polar/rectangular conversions, as you showed, if you have two real numbers in X and Y and you do convert to polar or rectangular treats them as the two parts of a complex number and then does the conversion as you would expect. If you have a complex number in X (eg you had two real numbers in X and Y and hit "Complex" or got it by taking a negative square root or whatever), and do the conversion to polar or rectangular it will work just on the complex number in X.
There were geniuses at work at hp back in the day -- the hp 28, 48, and 42 are all amazing devices.
another great video ! Free42 : An HP-42S Calculator Simulator for Linux, Android, IOS, Windows too
Thanks for the encouragement. Good point about Free42. That’s actually what I used before deciding to buy the DM42.
@@scottcollins7513 DM42 is based on Free42 code. Please thank Mr. Thomas Okken, and he'll be happy.
Very useful, and easy to follow! Thanks!
Appreciate the encouraging comment -- good to know there are people out there who like this sort of thing.
Great video. Used along with Logan West's. Lost all my old programs due to a inadvertent buttons getting pressed while 42 was in briefcase. (Keep Button Side In lol). This was a great help in getting me up to speed again. Thanks!
Glad it was helpful, Harmon. Thanks for letting me know! Cool that you have an original (presumably) 42S.
I recommend backing up all files, states, off images etc. and keep a usb cable with you (in your briefcase). I use the DM42 daily at work and can connect to my work laptop without having IT involved.... I owned tons of calculators (graphing and scientific) and the DM42 is like my laptop, it goes wherever I go.
Thanks that was awesome, Finally learning how to use mine.
Appreciate you saying so. Thanks for the encouraging words. The DM42 is superb.
Nice video. Watching this reminded me of one of the idiosyncrasies of the 42S that bothered me. When you are entering a complex number, you enter the magnitude first, then the angle. When you are entering a vector, it's the reverse.
Thank you for the kind words. YES, I agree that the inconsistency is strange. Was not aware of the vector behavior you are describing, but I have run into the same thing when using CONVERT from rectangular to polar and vice versa.
It is because the stack is upside down (bottom-up). If the stack was the other direction (top-down) then the apparent inconsistency goes away.
There may still feel like an inconsistency, but it's introduced by the COMPLEX function not following previously established input convention.
Interesting video as usual. Although the DM42 has roots in the HP41 which I had may years ago, I find it difficult to follow the keystrokes. Entering matrix seems quite tedious, the solver is clunky. I guess I have been spoiled by graphing calculators like my current favourite, the HP Prime
First, thank you for letting me know you found the video interesting.
Following the keystrokes is made worse bc the DM has a setting for alpha mode that changes things up from the normal HP 42S (e.g. using shift-1 to enter 1). It’s a bit less intuitive, too, than the HP 28 and 48 in terms of when ENTER is required and when not, but that’s a minor quibble. Also, I’m going fast bc the video is already long enough. Wonder if I am striking the right balance?
I disagree about matrix entry. I think it works well. I actually prefer entering matrix on this calc compared w the HP Prime, but the Prime has the big advantage of showing the contents of the matrix once entered (the DM42 does not).
100% agree that the solve function is clunky compared w the Prime and 28/48 and the Casio 991EX and TI-36X Pro. It’s fine for entering something you know you’ll use again and again. But, for a quick, one time use it is too keystroke-intensive to want to use.
Are they keys stiff or they are comparable to the 48GX? I saw in other videos that the keys were stiff?
Cheers
They feel fine to me and not too stiff. There was a design improvement that happened right around the time mine was purchased - but, I’m not sure if I have the new and improved keyboard (probably) or the original. That said, the keys on my HP48GX and HP28S are somewhat better.
My HP48GX died earlier this year and I got the SwissMicros DM42 to use as a replacement. The 48GX was awesome.
The display and simplicity of the DM42 (and the hp 42S) are both advantages, but it is no 48GX. It really depends what you use it for. For me, the DM42 is better. But, I've been thinking I might give my old hp 28S another whirl.
@@scottcollins7513 My HP 48GX was most useful for matrix operations solving a system of equations, but where it really rocked was phasors for AC circuit analysis
@@stevebjee I understand the matrix operations bit, but have no experience w/ the AC circuit analysis (phasors). 48GX is great w/ matrices and vectors -- better than DM42. If you really miss your 48GX, you might explore either buying a used one (they are quite pricey generally) *or* investigate some of the people who are modifying their DM42 to become a 48 as I understand. There was a Droid48 app for android that worked well -- but you'll miss the awesome keyboard of the 48. One other idea would be to get an old 28S which is like a 48GX "lite" - costs significantly less and better display than 48, but also very old at this point - they are out there, though.
@@scottcollins7513o comprar una hp 50G de segunda mano.
la hp 48GX, es muy buena (yo tengo una), sobre todo el teclado ; pero la hp 50G, está 3 pasos arriba, y lo mejor no te costará nada acostumbrarte a ella.
5:56 ...My hp 17bII+ solved the universal gravitation equation instantaneously-and without having to rearrange the equation; hp 17b solver is SO intuitive and easy!
/hp solve
DM42 is definitely not efficient in this regard -- my TI-36X PRO and CASIO fx-115ES 2nd ed are both much more intuitive. Thanks for the comment.
@@scottcollins7513 ----Today, there are only two calcs that I really need, and for very specific reasons: the TI-36X Pro and the venerable hp 17bII+
..... The TI-36X Pro, because it saves enormous amounts of scrollable calculation/answer history, far more than Casio scientifics, and especially because no Casio even saves calculation history after power-down.
..... The hp 17bII+ because the Solver is out-of-this-world easy, intuitive, and when you key-in an equation, the hp 17 instantly creates elegant soft menus at the bottom of the LCD of all the variables in the equation; so beautiful!
..... Furthermore, the hp 17bII+ ensures that any equation you key-in is mathematically valid before you attempt to solve it. So handy! ...I keyed-in the complex Colebrook-White equation for determining the friction factor in a pipe carrying water. Colebrook-White equation is an implicit equation such that it has the friction factor variable "f" on BOTH sides of the equation. But my hp 17bII+ handled it with engineering agility, --this in a compact shirt-pocket sized calculator the way God intended!
/Silicon Valley Regards
@@GeoCalifornian I just made a video today showing the way TI-36X Pro excels in handling past expressions and results, making them easily accessible for subsequent usage AND keeping them when you power off or switch modes (here's a link in case any one is curious: czcams.com/video/beUZrvdnPG8/video.html).
As for the hp 17bII+, I've never used it, but what you are describing and from what I can see in images of the calculator, it sounds very similar to the approach used w/ the hp 28S and 48GX. What's subtle, but great about the approach is that you can make in-between calculations and then save those to the variables as you go. Agree that it is very intuitive.
Thanks for the Silicon Valley Regards... next time please send some of the weather -- tired of snow/cold in my part of the US!
@@scottcollins7513 ----Scott I will check out your newest TI-36X Pro video!
.... In the meantime, I witnessed the engineering prowess of my pocket hp 17bII+ by solving the Colebrook-White equation for friction factor in a pipe.
/hp solve
@@GeoCalifornian Just looked that equation up. That's a bit of a beast (flashback to fluid mechanics). Cool that the 17bII+ solves it with ease. I may have to give that one a try on the lesser calculators to see if they can handle it.
I need a Degrees, Minutes & Seconds button this calculator does not seem to have one. Is it in a menu someplace? Can it be called up quickly?
Hi, Bill. It does have the function that's easily accessed. Look under "CONVERT" menu. The only weird bit is that, for example, 12 deg 34 min 56 sec is entered as 12.3456.
Nice handwriting too!
The handwriting tool was a Version 1 reMarkable. The Version 2 has a better casing, rest is the same.
Any chance of doing this with the DM41X?
I do not own that calculator (DM's are nice but they are not cheap!). Perhaps Logan West would be willing to put it together -- his channel is at czcams.com/users/loganswest
Hi, it is possible to add grades, minutes and seconds?
Your speaking of gradians (e.g. 50 gradians = 45 degrees)? Regardless, I believe you would have to write a program to do that, but it would be relatively simple and you would only have to select that program (function) any time you wanted to do the conversion.
Is it a graphing calculator?
It is not. There may be some special programs that allow it to graph, but it is/was not designed as a graphing calculator.
i cannot update it, and now it is stuck in the bootloader screen, even when I reset and/or remove the battery.
Reach out to SwissMicros. They are small enough to actually help out customers.
@@scottcollins7513
they are not answering
Where can I buy it?
I bought mine directly from SwissMicros (www.swissmicros.com/). I think that is the only way in US to buy new.
2:33 "Hopefully you can visualize that" ... No I can't, without writing the rearranged equation down on paper... the solver on the HP17BII is more intuitive in this regard.
Agree -- RPN takes some getting used to, and even then, it's more intuitive to use a solver that allows you to type in the equation exactly as it appears on your paper and then solve for the variable of your choice. Casio fx-991EX and TI-36X Pro are both strong at this.
@@scottcollins7513 --I am bidding on an HP17BII right now... the Solver function is so functional for engineers, contractors, nurses, et al... I don't know how I missed it all these years...
...Take a look at how elegant and intuitive it is:
(Variables in your equation are shown on the soft menu, and any variable can be solved WITHOUT the need to rearrange the equation; simple and elegant!)
Just scroll over to the 1 1 : 5 5 minute in the video for the fun to begin...
czcams.com/video/fVO6HoT2pCE/video.html
/Silicon Valley Regards
@@GeoCalifornian Agree that it is a better approach. The HP28S and 48GX have the same general sort of solvers.
the 42 is excellent for finding roots. you are supposed to use the solver, which you didn't use.
Correct me if I'm misunderstanding you, but the solver is good for finding a single root, but to find the other roots requires knowing where to look for them -- in other words, you have to provide the 42 with a starting point from which to iterate.
@@scottcollins7513
Yes, correct. I have not used the other brand you mentioned, but I assume it finds all the roots at the same time? I guess that might be better in a classroom environment.
@@tallswede80 Yes, as you correctly stated, there are other calculators that will just give the various roots at the same time which is great for a math class.
@@scottcollins7513
Then again, classroom environment is artificial, so it is a mistake to design tools that are only to be used inside a classroom. Ultimately the classroom is a means to an end, but teachers these days act like it is an end in itself.
@@tallswede80 In defense of teachers, they are told "you will teach to these standards" which removes so much flexibility from the process. 100% agree that teaching is meant to equip, not to be an end in and of itself.
The 27S solver is sooooooo much faster and easier than the 42.
I loved the hp 28s solver, too. Definitely better than the 42s.
Why don't you mention that it cannot communicate with a computer because the USB port is defective on the calculator!
Mine works. I have both exported and imported programs via USB.
In what way would a 48 "blow this away"?
First, know that I really like the DM42 and appreciate its overall simplicity (and superb display).
Some things the 48 offers that the 42 does not:
- Infinite stack
- Full-blown directory structure (you can organize all your programs by topic, etc.)
- Solver - super powerful and easy to use - can embed/nest formulas within formulas
- Units and Unit Conversions (as complex as you want, it can handle them)
- Vectors that you can work directly with - 42 can do similar ops, but the 48 is simpler
@@scottcollins7513 Thx for the follow up.
I hate this calculator because why would you put pi as a second option
Probably b/c its designers regard pi as highly irrational.
@@scottcollins7513 Casio has the same issue as well and some HP models. For a frequently used button the second shift is an insult
@@gvi341984 It does seem like there is always some design decision that makes us scratch our heads. I have never minded pi being shifted function, but I would if I did a lot of work w/ it (one cool thing about the 42 is that you can write little programs -- to compute the area of a circle for example). Even the TI-30X Pro Mathprint has factorial as a primary key, but square root as a shifted function. But, the layout of the keyboard is very logical. I'm sure there is a lot of debate going on when these devices are getting designed. And, it is one of those things where you are never going to make everyone happy.
@@scottcollins7513 Shift function doesn't make sense for root and pi since they are used so often.
@@gvi341984 this is your feeling. Many people will find this design really equilibrated. I do ;-) (I do own Prime , 48GX, 28s, even a Casio 991EX oops!) I really like this DM42 even if it's not perfect)