DM41X Info - John's Vademecum

Try to learn something about everything, and everything about somethingThomas Huxley “Darwin's bulldog” (1824-1895)
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<-[[.:]]
====== DM41X Info ======

<WRAP col2>

{{ :public:calculator:dm41_1.jpg?400 |}}


{{ :public:calculator:dm41_2.jpg?400 |}}


{{ :public:calculator:dm41_3.jpg?400 |}}

{{ :public:calculator:2022-05-24_23.23.38.jpg?400 |}}

</WRAP>

===== Purchase Information =====

  * Date   : February 2022
  * From   : Swiss Micros (Direct)
  * Price  : £185
  * Serial : 01266
  * Battery Swap
    * 22/9/22
    * 11/02/25
 


===== Firmware =====

^Date^Serial No.^DM41X Version^DMCP Version^Firmware Files^
|24/05/22 |01266| 2.1 | 3.20 |{{ :public:calculator:dmcp_flash_3.20_dm41x-2.1.zip |}}|
|27/07/24| 01266| 2.2 | 3.25 | {{ :public:calculator:info:dmcp_flash_3.25_dm41x-2.2.zip |}}|
|21/12/25 | 01266 | 2.3 | 3.28 | {{ :public:calculator:info:dmcp_flash_3.28_dm41x-2.3.zip |}}|

===== RTC Correction =====

  * approx. error +3.5s/d = +40.5ppm
  * Correction factor C from ''C = 2^20 P /(10^6 + P)''
  * Approximations : 
    * ''C = 1.04858 P''
    * ''P = 0.953674 C''
  * Calculated ''C = -42.47''

Put a text file ''/rtccalib.cfg'' in root directory of FAT drive with contents:
<code>
-42.47
</code>

==== Update 28/5/22 ====
After a period of observation the rate is now over-corrected. Try reducing correction to ''-37.5'' which corresponds to a ppm error of ''35.76ppm'', or ''3.26 s/d''.



^Date Start^Date Check^Accumulated Error (s)^Rate Error (s/d)^Comments^
|28/3/22 |24/5/22 | |-0.1 |correction applied (C=40). Uncorrected error +3.5|
|24/5/22| | |  |new correction C=-42.47 |
|24/5/22|25/5/22| |-0.3 |new correction in wrong direction? |
|28/5/22|  | |-0.3|still over-corrected. New factor: -37.5. DM41X reports this is a correction of -35.3ppm |
|28/5/22|31/5/22 |  |+0.2 | Now under-corrected? Difference across 3 days is only 0.5 seconds, so perhaps needs longer to reduce reaction-time-error|
|28/5/22 |28/6/22 |  | +0.1 |Almost 1 month later. Delta 31/5/22 = -15.7s, Delta 28/6/22 = -11.6s. +4.1s in 28 days  |
|28/5/22| 8/7/22|  | +0.1 |Delta -10.1s |
|28/5/22 | 21/9/22 | | + 0.2 | Delta +1.2s. Still slightly under-corrected but good enough  |
|28/5/22 | 15/4/23| -7.6 | +0.0 | Delta -7.6s in 322 days = 0.02 s/d |
|15/04/23 | 22/11/23 | +33.3   | +0.2   | 33.3s in 221 days = 0.15 s/d |

==== Update January 2026 ====

^Date Start^Date Check^Delta^Latest Rate Error^Average Rate Error^Comments^
|23/01/26 |  | +2.7 |  | | New Period: correction-35.3ppm |
|23/01/26| 24/01/26 | +2.6 | -0.1 | -0.1 | After 24 hours |
|23/01/26| 26/01/26 | +3.0 | +0.2 | +0.1 | After 3 days |
|23/01/26| 27/01/26 | +3.2 | +0.3 | +0.1 | After 4 days |


===== Notes =====

==== Complex Numbers ====

I'm using the ''41Z complex number'' module by Angel Martin to add a 4-level complex number stack. It's a bit confusing at first to get to grips with, but adds a lot of functionality to the the DM41x.

After a bit of trial and error (this is my first play with a "plug-in module" after all) I discovered the simplest way to make the keyboard function normally, and get easy access when needed to the complex functions, was to assign a USER key (usually the statistics summation key ''∑+'' to the 41Z module function ''∑ZL''. 

Each press of ''∑+'' now temporarily modifies all the keys to access specific 41Z functions. The functions available are extensive, through the use of the <key>SHIFT</key> key and by multiple presses of the ''∑+'' (henceforth referred to as  ''Z'') key. 

I drew out a diagram to show the various functions available. 

{{ :public:calculator:2022-02-18_23.03.17.jpg?400 |}}

Once a selection is made the keyboard switches back to its normal behaviour, so all the usual functionality is available.

Most of these are unlikely to be used often - and it's also possible to make a much narrow selection of 41Z functions and make your own ''USER'' assignments, rather than use the ''∑ZL'' keyboard - although this might mean you block access to inbuilt functions you might want - which would mean switching out of USER keyboard mode at times. At the moment the ''∑ZL'' option seems the most versatile.

Many of the 41Z functions available are beyond my pay grade and unlikely to ever find a use, but the Complex Keyboard still makes things much easier to deal with.

For example the two keypresses:

<key>Z</key>  <key>1\x</key>

is much easier than the 7 it would otherwise need to invert a complex number 

<key>XEQ</key><key>ALPHA</key><key>Z</key><key>I</key><key>N</key><key>V</key><key>ALPHA</key>
I need to practice finding the right function (the main ones printed on the keyboard as well as the new ones provided by 41Z's ''∑ZL'' keyboard, but my fingers are slowly starting to move in the right direction.

One thing I do notice, though, as that due to the need to press various keys (''XEQ, ALPHA, SHIFT'' etc) it's sometimes possible to make a real mess if you miss a vital key in the middle of entering lots of data & instructions and find your stack totally screwed up, or several lines of program code full of nonsense....  

I'm sure it'll all become second nature soon enough.

/*
<WRAP group>

<WRAP half column>
{{:public:calculator:2022-02-18_23.42.07.jpg?300 |}}
</WRAP>

<WRAP half column>
{{:public:calculator:2022-02-18_23.41.20.jpg?300 |}}
</WRAP>

</WRAP>
 
*/

{{:public:calculator:2022-02-18_23.42.07.jpg?300 |}}
{{:public:calculator:2022-02-18_23.41.20.jpg?300 |}}

----

==== HP16C Emulator module ====

This is another interesting module to add the functionality of the HP16C - the **Programmer's Calculator** designed to handle calculations in various mathematical bases as used in computer programming and networking : Binary, Octal, Hexadecimal and Decimal. I adds much more value than the rather basic functions in the //Advantage Pac// module.

After much trial and error I found a combination of HP16C module and //Library 4// library that worked correctly. The ''HP16C'' module //needs// the ''Library 4'' module, but I found some problems with different versions. Using the versions contained in the //Swiss Micros// package had a weird bug - the **16* ** (multiplication) function simply didn't work. I found a post by Angel Martin on the HP Calculator Forum with a ZIP file containing the 2 modules that //**worked**// correctly.

Here is the zip file : {{ :public:calculator:hp-16c_rev.1a.zip}}

I'll make a separate guide to using the main features here [[public:calculator:guides:hp16c_emulator|]] 


===== Guides =====

[[public:calculator:guides:start|]]



===== Swiss Micros Info =====

  * Firmware      : [[https://technical.swissmicros.com/dm41x/firmware/]]
  * Documentation : [[https://technical.swissmicros.com/dm41x/doc/dm41x_user_manual.html|User Manual]]
  * Product Page  : [[https://www.swissmicros.com/product/dm41x|DM41X]]


===== Issues =====

  * Arrived new with a speck of dirt behind the glass in front of the LCD. 
    * Able to remove by carefully prising the glass from its bezel (it's held in with double-sided tape)

====41Z Deluxe Module ====

++++ Weird behaviour with its "common factor" display | 

  * A number such as ''10 + j 1'' //displays// as ''10(1 + j)'' which is **wrong**
  * example:
    * ''( 5 + j 10 ) + ( 45 - j 5 ) '' is really ''( 50 + j 5)''
    * calculator displays ''50(1 + j)''
    * the actual numbers in the registers are correct (50 for Real in X and 5 for imaginary in Y) but the answer displayed as ''50( 1 + j )'' is badly misleading.
    * doing further calculations with the number on the stack is correct, as long as the answer doesn't have the same display-factorisation bug to mislead you. The only way to be sure is to look at the underlying X and Y stack registers. This spoils the nice ''ALPHA'' display of complex numbers, though.
    * it appears whenever the real and imaginary numbers are related by factors of 10 (e.g. 5 and 50, 2 and 20, 3 and 3000, 25 and 250)
  * __My__ Solution is to abandon the ''deluxe'' module and revert to a previous version, __not deluxe__ : ''HP41Z Complex Number Module'' version ''4L'' and the appropriate ''library4'' module.
    * This module seems to handle the ''common factor'' display correctly. 
      * it **does not** show ''50 + j 5'' as ''50( 1 + j )''
      * it **does** show ''50 + j 50 '' as ''50( 1 + j )''
    * It requires a different ''USER KEY'' assignment:

 <key>SHIFT</key> <key>ASN</key><key>ALPHA</key><key>Z</key><key>K</key><key>B</key><key>R</key><key>D</key><key>ALPHA</key><key>'Σ+'</key> 

=== Module files that work (for me) ===

  * {{ :public:calculator:info:41z.mod |}}
  * {{ :public:calculator:info:library4.mod |}}
  * See [[public:calculator:guides:41z_module|]]

++++

=== Update September 2024 ===

The factorization error in the ''deluxe'' version has been fixed by Angel.... 

[[https://forum.swissmicros.com/viewtopic.php?f=26&t=4029 | Swiss Micros forum discussion about the issue ]]

  * the fixed version {{ :public:calculator:info:41z_bs_2x2_2_.zip |}}
  * My page [[public:calculator:guides:41z_module|]]




===== DM41X Program Listings =====

  * See [[public:calculator:progs:dm41x_progs|]]



Page Updated : ~~LASTMOD~~

{{tag>calculator dm41x}}
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