Swissmicros DM42 Calculator

[jyl]

We have talked about calculators here. I finally did it and ordered a Swissmicros DM42 which is a modernized HP42S. I’ll post when it arrives - shipping from Switzerland (!).

There is a WP43S project, intended to create an emulator for the ultimate RPN calculator with loads of math, stat and engineering fx. The plan is to sell this as a physical calculator, manufactured by Swissmicros. I figured I should see what the quality of these Swissmicros calculator is like, on this DM42, before getting ready to plunk down $ for the DM43 or whatever it will be called.

Oddly, I have no use at all for any advanced math, stat or engineering functions. I just like calculators. If I can find time to fumble through it, I’ll probably write some financial programs for my DM42.

[fanaudical]

https://forums.pelicanparts.com/off-topic-discussions/1063611-hp-rpn-geeks-what-do-we-think.html

I expect a full review - am still thinking about buying one...

[Nostril Cheese]

[masraum]

Very cool. Can't wait to hear what you think.

[jyl]

The calculator looks and feels good. It is solid and surprisingly heavy. On the back and upper side there are IR transmitter, micro USB, and reset button.




The screen is reasonably high resolution and decent contrast.



The buttons are fine, though not as good as the old school HP calculator buttons. The printing is ditto.

[jyl]

I forgot to attach this image to the previous post.

I haven’t started playing with it yet.

[tadd]

Looks like the HP my first wife (passed away many years ago) got me when I started school and we were getting serious. It was a lot of money back then for two young(ish) broke people.

[Captain Ahab Jr]

Originally Posted by Nostril Cheese

I'm not cleverer or knowledgeable enough to contribute so here's a re-post just because it was so funny

[MBAtarga]

$230 on Amazon - and I think I paid a little less than that for my HP 42CV back in 1980 as a EE major at GaTech. Impressive 34 decimal digits of precision - I think that 5 or 6 would be plenty unless you're designing nuclear reactors or something....

[arcsine]

My wife just put batteries in her HP 15C for the first time in decades. I've never got the reverse-logic HP programming but she was very happy. To each their own I guess.

[vash]

I kinda want one! 230$ hurts

[RWebb]

nice - I'd like a modern hp97 (I had a 67 which was better for skiing it up a mtn. to run heat exchange models...)

[masraum]

I'm super bummed that my old College HP 32S II died. I think one of the batteries leaked and the screen was trashed. It was probably at least 25 years old.

I've got RPN on my PC and phone, so I don't see a reason to buy another. If I did, I'd probably try to get an HP 35S. If I couldn't get that, then I'd probably go with the Swissmicros, and then I'd go for the big daddy HP 50 at $499. Again, no reason to get one. (But I really do miss my old one).

[jyl]

So right off the bat, I need to learn to write and store programs, because this thing has no financial functions built in.

[jyl]

Lawdy, the HP42S manual is over 200 pages long. Then there’s the programming guide and the supplemental Swissmicros manual. I just want to compute yield to worst! Waaah!

Oh, I figured out why it is heavier than I expected. The case is stainless steel with a PVD coating. Cool.

[fanaudical]

Very cool. If I remember correctly, the programming portion isn't too difficult (though I haven't written one in years). I have a couple of the 42S programming books; will look to see if I have any good examples of the financial functions.

Do the keys "click" or have otherwise satisfying tactile feedback when you push them?

What's it use for batteries?

[masraum]

I would think you could find a program for just about anything you needed/wanted online someplace. I'm sure there's a forum or something for HP RPN geeks.

[jyl]

Originally Posted by masraum

I would think you could find a program for just about anything you needed/wanted online someplace. I'm sure there's a forum or something for HP RPN geeks.

There isn’t that much of what I want. RPN/HP geeks are mathy and sciency, seldom interested in finance. There’s some basic amortization etc programs. Unless I’m missing it.

What I think I need to write.
1. Value of bond at given discount rate.
2. Yield to maturity of bond (use #1 as subroutine, recursively)
3. Yield to call and to put of bond (use #1 as sub)
4. Yield to worst (use #2 and #3)
5. Value, greeks of option
6. Value, greeks of combination of options and underlying stock (use #5)
7. Implied volatility of stock at given option value (use #5 as sub, recursive)
8. Value of convertible bond (use #1, 5)
9. Option position to hedge given stock position to desired greek (use #6)
10. Value of equity given growth, margins, capital structure, discount rate, multiple
11. Implied growth or margins at given equity value (use #11)
12. Basic loan amortization, present values
13. Basic IRR (this could be sub for #2)

This will be just for fun, I don’t see actually using most of this stuff, and certainly not on a calculator.

A lot of this is backing into a number, so I see doing a lot of it recursively, unless I can use Solver. I tend to think that way - does X make sense, what would that imply for Y and Z?

The DM42 has expanded DATE functions that the HP42S didn’t, which will make this easier. It also has far more memory and a far faster processor. You can develop the programs using the Free42 emulator on your PC or Mac, then upload to the calculator. I feel like I need to plan all this out ahead of time as I’d like the various programs to use the same set of variables and registers.

[jyl]

Originally Posted by fanaudical

Very cool. If I remember correctly, the programming portion isn't too difficult (though I haven't written one in years). I have a couple of the 42S programming books; will look to see if I have any good examples of the financial functions.

Do the keys "click" or have otherwise satisfying tactile feedback when you push them?

What's it use for batteries?

They don’t audibly click though I think there is a beep you can enable, there is a tactile click so it isnt mushy, but it isn’t as distinct a tactile click or as tall a key as, say, an HP12C or other older HP. I’d say the keys are okay but not the pleasuresome experience of a vintage HP calculator.

Internal, rechargeable battery, charged using USB [edit - not sure about that, USB powers the calc but unclear if it charges it], I read it is supposed to last a very long time between charges.

If you find financial programs, I’d love to see them. I just realized I should look for HP41CX financial programs too.

[fanaudical]

If you primarily intend to back into a number then I do recommend using the solver. It's generally easier to setup than an executable program. Let me know if you need some solver examples.

I did find my 42s supplemental programming books this morning; it's all ME and EE stuff. Thought I had a financial book in the stack but was incorrect.

Kinda disappointed about the feel of the keys - that is, oddly enough, one of my primary reasons for wanting a calculator again - the nostalgic process of working through problems by hand. I still do that when it's important. Math is a tool to gain insight to the problem - it's not just about the numbers...