Friday, February 23, 2018

Review: SwissMicros DM41L

Review: SwissMicros DM41L

General Information

Company:  SwissMicros,
Type:  Programmable Scientific
Memory:  319 registers (2,233 steps),
(Firmware V 25 gives additional archive storage)
Battery:  CR 2032
Years:  Current (2015-)
Cost: $138 U.S. dollars (February 2018), 129 CHF

There are two models: the DM 41L and the DM41.  The DM41 is a credit card sized version of the DM 41L (99 CHF).  For me, I prefer the larger sized DM 41L as I do have large hands.  Both offer the same functionality. 

The size of the DM 41L is about the size of the Hewlett Packard HP 12C and HP 15C.

Note:  When I mention the DM 41L, this applies to both the DM 41L and the credit-card sized DM 41. 

The delivery for me (from Switzerland to the United States) was really fast, much faster than I expected.  I was motivated to purchase a DM 41L because I will turn 41 years old in March.  This is my first calculator from SwissMicros. 

The HP 41C Comes to the 21st Century

The DM 41L is a clone of the very popular HP 41CX calculator, but in a landscape form.  The HP 41CX was the final version of Hewlett Packard’s HP 41C series produced for most of the 1980s.  The HP 41CX included a time module, which gives the calculator a timer, stopwatch, and calendar operations.  Also the HP41CX included an extended functions and memory module.  The base HP 41C had 63 registers, while the HP41CX, and the DM 41L start you off with 319 registers.

Each register could either hold a number or seven program steps.  At any time you can designate how many registers to dedicate to holding numeric constants by executing the SIZE command.

The DM41L and DM 41 come with the following modules installed:

* Extended Memory and Functions (EX FCN 2D)
* Time Module (CX TIME)

I am so happy that the Time Module is included, because the DM41L has the days between dates function, so I don’t need to program the convert date to the Julian Date algorithm.  (I love the days between dates function, and I do feel that, and the date add functions should be standard on all calculators – OK, rant over).


The keyboard is a pleasure to use.  The colors of the fonts are beautiful, with the labels having great contrast between text and keyboard background.  The keys are very responsive and provide great feel for each press.  I have seen some reviewers comment that the keys are at first hard and need some breaking in, however, this is not the case for me. 

The only thing is that, I wish the ON button was the same height as the other keys, as the ON key is sunken a bit.  This could be personal preference as the ON key works just as well the rest of the keys.


The DM 41L can the connected to the computer where you can back up your memory, restore memory, load programs, and update the software.  The current version at the time of this review is Firmware 25.  Firmware 25 adds the X-Memory module, which allows for additional achieve memory. 

The cord used is a mini USB-RS232 cord, which is the same one used to connect the TI-84 Plus CE.

The Swiss Micros will have links to the required connectivity software and detailed instructions. It took me a little time to get the hang of it, it gets easier after I get the procedure. 

Get the DM 41L ready for connectivity use by having the calculator off, then holding the [ x ] (C) button and the [ ON ] button.

What Time Is It?

You can have the DM 41L tell you time and date by first having the calculator off, then holding the [ Σ+ ] (A) key, then the [ ON ]. 

In a similar fashion, you check the revision software by holding [ LN ] (E) then [ ON ].

SwissMicros’ other [ ON ] + key combos are listed here:


The DM 41L’s programming module is RPN keystroke, like the HP 41C.  If you know how to program the HP 41C, you can program the DM 41L.  Due to the popularity of the HP 41C, there is of ton of programming information online.  The Museum of HP Calculators has an entire software library thread dedicated to the HP 41C ( ), which should work on the DM 41L with no problems.

A great online source to the programming and operating the HP 41C and the DM 41L can be found here:  Special thanks to Greendyk!   ( )


Do I recommend the DM 41L to purchase? 

That would be a 100% YES!

SwissMicros deserves all the praise from their customers, high quality calculator and high quality work.  I have very happy with my purchase. 

SwissMicros has several other calculators, including the DM 42 which was just released.  Please feel to check it out.


This blog is property of Edward Shore, 2018.

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