Author Topic: EEVblog #1159 - World's Most Precise Pocket Calculator  (Read 21419 times)

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Online EEVblogTopic starter

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EEVblog #1159 - World's Most Precise Pocket Calculator
« on: December 17, 2018, 12:58:33 pm »
One item mailbag!
A look at the Swissmicro DM42, the world's most precise pocket calculator.
A clone and improvement of the famous HP42S, with open source firmware based on the Free42 platform.

https://www.swissmicros.com/dm42.php
http://thomasokken.com/free42/


 
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Offline dr.diesel

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Re: EEVblog #1159 - World's Most Precise Pocket Calculator
« Reply #1 on: December 17, 2018, 01:39:50 pm »
That is quite nice!  Is the display cover glass or plastic?

Offline iMo

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Re: EEVblog #1159 - World's Most Precise Pocket Calculator
« Reply #2 on: December 17, 2018, 05:27:58 pm »
I think the "most precise pocket calculator" is the WP-34S.
https://sourceforge.net/projects/wp34s/
It uses DecNumber library with up to 50 decimal places precision.
« Last Edit: December 17, 2018, 05:32:15 pm by imo »
 

Offline bsudbrink

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Re: EEVblog #1159 - World's Most Precise Pocket Calculator
« Reply #3 on: December 17, 2018, 09:19:13 pm »
Just so you know, YouTube has this video marked as "unlisted".  I'm not sure what this means, but I don't see it on my YouTube account subscription page.
 

Offline darik

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Re: EEVblog #1159 - World's Most Precise Pocket Calculator
« Reply #4 on: December 17, 2018, 11:53:41 pm »
To show the full precision, use shift-decimal (SHOW).
 

Offline Dubbie

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Re: EEVblog #1159 - World's Most Precise Pocket Calculator
« Reply #5 on: December 18, 2018, 12:56:26 am »
I have this calculator, the only issue I have with it is that the button feel is not as nice as it could be. It is my daily driver at work though.
 

Online EEVblogTopic starter

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Re: EEVblog #1159 - World's Most Precise Pocket Calculator
« Reply #6 on: December 18, 2018, 02:13:37 am »
To show the full precision, use shift-decimal (SHOW).

Ah, that works, but unfortunately does not show up long enough to read it!
UPDATE: You have to continue to hold down the button to keep it showing

« Last Edit: December 18, 2018, 02:15:55 am by EEVblog »
 
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Online EEVblogTopic starter

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Re: EEVblog #1159 - World's Most Precise Pocket Calculator
« Reply #7 on: December 18, 2018, 02:17:54 am »
Actual Calculator Forensics result:
 
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Offline iMo

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Re: EEVblog #1159 - World's Most Precise Pocket Calculator
« Reply #8 on: December 18, 2018, 03:35:20 am »
It seems Dave's buttons died :)
A big pain all these recent attempts to mimic the original HP-clicky buttons. The WP-34s (HP-30b hw) I own still clicks, but mostly because I stopped using it in order to save the buttons :)
The thin plastic pins (about 2.5mm long 1mm dia) pushing onto the metal dome usually bend/broke when pushing a little harder.

The DM-42 does not use such long pins, it may last a little bit longer. Not sure you get such HP-feel with it, however.
And my HP-25 and HP-48GX is still clicky..
« Last Edit: December 18, 2018, 03:39:08 am by imo »
 

Online BrianHG

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Re: EEVblog #1159 - World's Most Precise Pocket Calculator
« Reply #9 on: December 18, 2018, 03:52:42 am »
Holly cow Dave!  Your enthusiasm shines through to the moon.  :-+
 

Offline inOr

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Re: EEVblog #1159 - World's Most Precise Pocket Calculator
« Reply #10 on: December 18, 2018, 05:41:53 am »
Once I tried to write a DEC Fortran program to solve a quadratic the high school way, the exact formula you know -b+/- sqrt(b^2 ...., I got a ridiculous answer, so I tried a numeric routine from the DEC collection and wow was that wrong!  So I programmed my own numeric routine and that worked.  Meanwhile, I used my HP xx scientific calculator.  I can't remember the precision, but the answer was bang-on.  They do have their uses...
 

Offline johnlsenchak

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Re: EEVblog #1159 - World's Most Precise Pocket Calculator
« Reply #11 on: December 18, 2018, 05:49:01 am »

Years ago,   I had a  real nice  programmable HP scientific    calculator    where I  wrote a programs  to  calculate  A/C   circuits when  it came to inductors and  capacitors   .
John Senchak "Daytona  Beach  Florida "
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Offline Fungus

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Re: EEVblog #1159 - World's Most Precise Pocket Calculator
« Reply #12 on: December 18, 2018, 11:55:17 am »
To show the full precision, use shift-decimal (SHOW).
I was shouting that at the screen while the video was running.  :popcorn:

Ah, that works, but unfortunately does not show up long enough to read it!
UPDATE: You have to continue to hold down the button to keep it showing

How many does it show? 12 digits?
 

Offline NivagSwerdna

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Re: EEVblog #1159 - World's Most Precise Pocket Calculator
« Reply #13 on: December 18, 2018, 01:38:24 pm »
Nice.  I have a poor man's version WP 34S .  I know 42S is super popular with the fanboys but IMHO it's a bit hard to live with unless you use it every day since the functions are hidden away... I think I prefer the ones that just have lots of functions on the buttons...

I also have a HP35S which is a nice compromise and not bad for a modern device.

 

Offline Gribo

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Re: EEVblog #1159 - World's Most Precise Pocket Calculator
« Reply #14 on: December 18, 2018, 04:07:32 pm »
Does anyone knows who manufactures the display? I have been looking for an E-paper display with fast response time for quite a while.
I am available for freelance work.
 

Offline iMo

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Re: EEVblog #1159 - World's Most Precise Pocket Calculator
« Reply #15 on: December 18, 2018, 06:28:00 pm »
LS027B7DH01 from Sharp Microelectronics..
 

Offline pauli

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Re: EEVblog #1159 - World's Most Precise Pocket Calculator
« Reply #16 on: December 18, 2018, 09:33:30 pm »
It's off by one in the last digit :)

Refer: http://www.hpmuseum.org/forum/archive/index.php?thread-10355.html


Pauli
 

Offline rsjsouza

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Re: EEVblog #1159 - World's Most Precise Pocket Calculator
« Reply #17 on: December 18, 2018, 09:44:04 pm »
I also have a HP35S which is a nice compromise and not bad for a modern device.
:-+ :-+ :-+
Although a bit more cumbersome to do base conversion when compared to my 48GX, the 35S is quite nice. (I leave my 48GX at home as I am afraid it will be stolen).
Vbe - vídeo blog eletrônico http://videos.vbeletronico.com

Oh, the "whys" of the datasheets... The information is there not to be an axiomatic truth, but instead each speck of data must be slowly inhaled while carefully performing a deep search inside oneself to find the true metaphysical sense...
 

Online EEVblogTopic starter

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Re: EEVblog #1159 - World's Most Precise Pocket Calculator
« Reply #18 on: December 18, 2018, 09:44:25 pm »
It's off by one in the last digit :)
Refer: http://www.hpmuseum.org/forum/archive/index.php?thread-10355.html
Pauli

Hey Pauli, long time no see, welcome to the forum!
 

Offline Spirit532

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Re: EEVblog #1159 - World's Most Precise Pocket Calculator
« Reply #19 on: December 19, 2018, 01:52:00 am »
I believe the display is a Sharp Memory LCD with the model number LS027B7DH01
It's a ridiculously low retention power graphical LCD, but it comes at a hefty price premium.
 

Offline Fungus

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Re: EEVblog #1159 - World's Most Precise Pocket Calculator
« Reply #20 on: December 19, 2018, 10:36:19 pm »
there is nothing like a portable scientific calc with a 10" screen and buttons the size of a thumb. I repeat, buttons with the size of a thumb.

 :wtf:

Some of us still have good eyesight and a bit of hand-eye coordination.
 

Offline floobydust

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Re: EEVblog #1159 - World's Most Precise Pocket Calculator
« Reply #21 on: December 19, 2018, 10:39:18 pm »
All these app-based calculators still suck compared to old tech.
I have a Sharp EL5103-S that rounds results to engineering units (milli, micro, nano, kilo etc.).
It's great instead for EE work, instead of converting exponents.

The pocket calc speed test I did was always 69! (69 factorial), I wonder how long that takes on this calculator. TI-30 LED was 2 seconds lol.
 

Offline rsjsouza

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Re: EEVblog #1159 - World's Most Precise Pocket Calculator
« Reply #22 on: December 20, 2018, 03:27:50 am »
there is nothing like using thumbs to press them, the satisfaction (or fun). and there is no printed words to rub off like casios.
My old Kindle Fire HD still has a beautifully coded HP-12C in voyager style. Although its size and functionality are quite nice, pressing virtual buttons is not the same at all. YMMV, though.

The pocket calc speed test I did was always 69! (69 factorial), I wonder how long that takes on this calculator. TI-30 LED was 2 seconds lol.
Heh, I did the same. My old Casio fx-39 took about 10 seconds! My dad's TI-59 did not have a built-in factorial function, and the best program I could make at the time took somewhere between 10 and 15 seconds.
Vbe - vídeo blog eletrônico http://videos.vbeletronico.com

Oh, the "whys" of the datasheets... The information is there not to be an axiomatic truth, but instead each speck of data must be slowly inhaled while carefully performing a deep search inside oneself to find the true metaphysical sense...
 

Offline Fungus

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Re: EEVblog #1159 - World's Most Precise Pocket Calculator
« Reply #23 on: December 20, 2018, 07:49:09 am »
My old Kindle Fire HD still has a beautifully coded HP-12C in voyager style. Although its size and functionality are quite nice, pressing virtual buttons is not the same at all. YMMV, though.

12C? Ew! That's a calculator for bankers.

HP does the 15C (scientific) for Android:

https://play.google.com/store/apps/details?id=com.hp.hp15c15&hl=en_US

(it turns into an RPN  four-banger when you rotate to portrait mode, too)
 

Offline rsjsouza

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Re: EEVblog #1159 - World's Most Precise Pocket Calculator
« Reply #24 on: December 20, 2018, 09:39:58 am »
My old Kindle Fire HD still has a beautifully coded HP-12C in voyager style. Although its size and functionality are quite nice, pressing virtual buttons is not the same at all. YMMV, though.

12C? Ew! That's a calculator for bankers.
It wasn't for me...

In reality, it is a great calculator for the real-world issues and served me well to go through the pitfalls of house financing back in 2010 and still is sporadically used for the eventual finance/investment.

Hey, a dude's gotta do what it is gotta do to offset the fact money does not grow in trees...

HP does the 15C (scientific) for Android:

https://play.google.com/store/apps/details?id=com.hp.hp15c15&hl=en_US
For scientific I will keep my HP48 simulator instead, though. It does not replace my physical calculator, but it is darn convenient.
Vbe - vídeo blog eletrônico http://videos.vbeletronico.com

Oh, the "whys" of the datasheets... The information is there not to be an axiomatic truth, but instead each speck of data must be slowly inhaled while carefully performing a deep search inside oneself to find the true metaphysical sense...
 


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