Review: Swiss Micros DM41X

 Review: Swiss Micros DM41X

General Information

Company:  SwissMicros, https://www.swissmicros.com

Type:  Programmable Scientific

Memory:  319 registers (at default) - calculator; 32 MB external flash

Battery:  CR 2032

Date:  September 2020 - current

Cost:  229 CHF, about $257.34 according to currency converter on December 12, 2020 (https://www.xe.com/currencyconverter/convert/?Amount=229&From=CHF&To=USD)

Current Software Version:  2.1 (November 13, 2020)

Case Included?  Yes

The DM41X is a long waited calculator, and joins the DM 41L and DM41 family.  The family runs HP-41CX firmware, including a clock, time, and date functions.    On February 23, 2018, I reviewed the DM 41L which you can see here:

http://edspi31415.blogspot.com/2018/02/review-swissmicros-dm41l.html

I am going to address the features that are specific to the DM41X, which is added to all the great features of the DM41 and DM41L.  

A Return to the Original Layout

The DM41X's keyboard is in a portrait design, like the original Hewlett Packard HP-41C family (HP-41C, HP-41CV, HP-41CX)

Instead of the row of ON, USER, PRGM, and ALPHA keys on the top row, the DM41X adds a column of keys to the right of the main keyboard:

ON/CLK:  ON/OFF button, the shifted CLK displays the current time

USR/SETUP:  The user keyboard.  SETUP shows the DM41X's system menu where stve states and RAW progams can be saved, USB communication can be activated, modules can be saved and loaded, system settings can be changed, and accessing the About screen.

Blue Key:  This is the ALPHA key

Backspace Key

Up Arrow: for program scrolling and debugging

Down Arrow: for program scrolling and debugging

PRG/SIZE:  The PRGM button.  The shifted function allows the user set the number of registers to be set for numerical constants.

R/S/VIEW:  Run/Stop Key, View prompts for a view of a register's value without affecting the stack.

The Big Screen

The DM41X has three screen settings that is set by the DSP key:

1.  All four stacks, T, Z, Y, and X are displayed.  This is my preferred display. 

2.  The X stack and the Alpha Register are displayed.  On the top of the screen:  alarms, the number of storage registers designated for numerical constants, free memory, the current program loaded and it's pointer location.  

3.  Two stacks, Y and X are displayed. On the top of the screen:  alarms, the number of storage registers designated for numerical constants, free memory, the current program loaded and it's pointer location.  

Connectivity

The DM41X's connectivity interface is in line with the DM42's connectivity interface.  Simply plug the DM41X with a USB-Micro B port, then on the calculator press [shift], [USR] (SETUP), 1 for File, 5 for Activate USB Disk.  The DM41X now acts as a USB storage device like a smart phone.  

You can take screenshots by pressing and holding [SHIFT] and [DSP].  Screen shots are saved as .bmp files under the disk's SCREEN folder.

Black and white images of 400 x 240 pixels, 1 bit depth, .bmp format, can be saved to the disk's OFFIMG folder.  Every picture in the folder will be shown on a rotated basis every time the calculator is turned off.  

Custom Menu

Pressing the CST key will give you access to a custom menu 16 available slots for commands and programs.  CST also gives access to Help, ROM Map, and USB Disk activation.  To learn about how to set up the custom menu, click here:  https://edspi31415.blogspot.com/2020/10/swiss-micros-dm41x-custom-menus.html.

Programming

The DM41X operates like the HP-41CX in its programming language except the DM41X has a lot more room for ROM modules.

Verdict

Like the DM41L, the DM41X is a winner.  The keys feel good, I love seeing all four stack levels on the screen, and I am fan of the custom menu built into the DM41X.  This is definitely worth a purchase.

If the price tag of DM41X is too high, consider the DM41 or DM41L.  They may not have a four line display or a custom menu, but the high-quality calculator software and firmware is still present.  Currently only the DM41L is in stock from Swiss Micros, at CHF 129.  

- - - - - -

Announcement

This is the last post for 2020.  I want to wish everyone Merry Christmas, Happy Holidays, and Happy New Year.  2020 has been a brutal year in every respect.  May 2021 be free from disease, war, economic, social, and spiritual struggle; and be full of joy, health, and happiness.  Thank you to my blog's followers and readers; I appreciate all of you!  Take care, and the next schedule blog will be on January 2, 2021.  

Eddie

All original content copyright, © 2011-2020.  Edward Shore.   Unauthorized use and/or unauthorized distribution for commercial purposes without express and written permission from the author is strictly prohibited.  This blog entry may be distributed for noncommercial purposes, provided that full credit is given to the author. 

HP 41C and DM41: Operations by Test, Messages, Block Storage

 HP 41C and DM41: Operations by Test, Messages, Block Storage  

The programs are inspired from a great calculator resource, "Calculator Tips & Routines Especially For The HP-41C/41CV", edited by John Dearing (see source below).   

Operations by Test

One of the tips presented is the selection of one of two opposite arithmetic operations based on a comparison between X and Y values.  This tip was provided by Bill Kolb (tip 2-7).  They are:

X?Y

CHS  (subtract if test is true)

+   (add if test is false)

X?Y

1/X  (divide if the test is true)

*  (multiply if the test is false)

X?Y

1/X   (take the root if the test is true)

Y↑X  (take the power if the test is false)

The following programs uses the test X<Y:

TESTAS:  X<Y  (subtract, y - x),  X≥Y (adding, y + x)

(^T represent the beginning of an alpha string)

01 LBL^T TESTAS

02 X<Y?

03 CHS

04 + 

05 END

Example:  

45, 13, XEQ TESTAS returns 32  (45 - 13)

13, 45, XEQ TESTAS returns 58  (13 + 45)

TESTMD:  X<Y  (divide, y/x),  X≥Y (mulitply, y * x)

01 LBL^T TESTMD

02 X<Y?

03 1/X

04 * 

05 END

Example:  

45, 13, XEQ TESTMD returns 3.4615  ( ≈ 45 / 13)

13, 45, XEQ TESTMD returns 585  (13 * 45)

TESTPR:  X<Y  (root, y^1/x),  X≥Y (power, y^x)

01 LBL^T TESTPR

02 X<Y?

03 1/X

04 Y↑X 

05 END

Example:  

49, 3, XEQ TESTPR returns 3.6593  ( ≈ 49 ^ 1/3)

3, 49, XEQ TESTPR returns 2.3930E23  (≈ 3 ^ 49)

Messages

With the use of AVIEW during a loop, you can display a loop up to 12 characters while the loop is running.   A CLD (clear display) is added after the loop's completion to clear the alpha display and show the stack. (tip 2-25)

The program TESTSUM adds a message while the 41C is summing numbers from 1 to X.   While this is not the most efficient way to tackle the problem, this illustrates the use of messages.  

01 LBL^T TESTSUM

02 STO 01

03 0

04 STO 02

05 LBL 01   // loop begins

06 RCL 01

07 ST+ 02

08 ^T ADDING...  // message

09 AVIEW   // display the message

10 DSE 01

11 GTO 01

12 CLD  // clear display

13 RCL 02

14 END

Example:

50, XEQ TESTSUM  

Display: ADDING..., then 1275

Block Storage

You can use indirect storage and the stack to store a constant in a block of consecutive storage registers.  A sample loop:

LBL %%

STO IND Y

ISG Y

GTO %%

Where %% is a label, and the loop variable is B.EEE  (B:  beginning register, E:  ending register) stored in this case, Stack Y.  (tip 10-1)

The program LOADBLK, prompts the user enter the value, beginning register number, and ending register number.

01 LBL^LOADBLK

02 ^T VALUE

03 PROMPT

04 STO Z     // keystrokes:  [ STO ]  [ . ]  ( Y )

05 ^T R%% BGN?

06 PROMPT

07 ^T R%% END?

08 PROMPT

09 1E3

10 /

11 +

12 STO Y  

13 RDN   // R↓

14 X<>Y

15 LBL 01

16 STO IND Y   // keystrokes:  [ STO ] [ shift ] [ . ] ( Y )

17 ^T STORING...    // message

18 AVIEW

19 ISG Y    // keystrokes:  [ shift ] ( ISG ) [ . ] ( Y )

20 GTO 01

21 ^T DONE

22 AVIEW

23 PSE

24 CLD

25 END

Try this:

Store π in R00 to R03 and e^1 in R04 to R07.

 

Results:  (Fix 4)

R00:  3.1416

R01:  3.1416

R02:  3.1416

R03:  3.1416

R04:  2.7183

R05:  2.7183

R06:  2.7183

R07:  2.7183

Source:

Dearing, John.  "Calculator Tips & Routines Especially for the HP-41C/41CV"  Corvallis Software, Inc.   Corvallis, OR.  1981 

Link on HP41.org (account needed):  http://www.hp41.org/LibView.cfm?Command=View&ItemID=320

Eddie

All original content copyright, © 2011-2020.  Edward Shore.   Unauthorized use and/or unauthorized distribution for commercial purposes without express and written permission from the author is strictly prohibited.  This blog entry may be distributed for noncommercial purposes, provided that full credit is given to the author. 

HP 41C and DM41L: Basic EKG Calculations

HP 41C and DM41L: Basic EKG Calculations

Introduction

The program calculates the following:

*  Lead II magnification, in mm

*  The mean axis deviation

*  The mean axis magnitude 

Given:

*  Lead I positive deflection, in mm

*  Lead III negative deflection, in mm

The mean axis deviation and magnitude are calculated by a rectangular conversion by the following coordinates:

X: Lead I positive deflection - Lead I negative deflection

Y:  Net Lead I deflection * 0.5774 + Net Lead III deflection * 1.1547

Mean axis deviation:  θ - 57°

The program also:

* Converts between the heart rate (rpm) and the R-R interval

* Use either parameter to calculate the Q-T interval, in seconds

heart rate = 60/R-R

Q-T interval = √(R-R)*0.39

The program is a translation of HP 67/HP 97 Basic EKG Determination, which itself is a translation of Steven A. Conrad's HP-65 program (HP-65 Users' Library Program).  See the source listed below.

Notes:

1.  Clear the assignments of keys A (Σ+) through E (LN) before running the program.  This must be done outside the programming environment.  Clear assignments to keys by ASN (blank) (designated key).  

Example:  Clear assignment from A: [ shift ] (ASN)  [ALPHA] [ALPHA] [ Σ+ ]

2.  Running EKG will turn the User Keyboard on.

3.  The program will set the calculator to degrees mode. 

4.  This program was entered on an HP 41C, and it should work on any simulator and Swiss Micros DM41.  

Instructions

1.  Run EKG.

2.  Determine Lead I net deviation and store it to register 01:

(in User's Mode) positive deviation Lead I [ENTER] negative deviation Lead I ( A )  

3.  Determine Lead II net deviation, storing net Lead III net deviation to register 03 and Lead II net deviation to register 02:

(in User's Mode)  positive deviation Lead III [ENTER] negative deviation Lead III ( B )

Result:  Lead II net deviation

4.  Compute Mean Axis:

(in User's Mode)   ( C )  deviation is displayed [ R/S ] magnitude is displayed

5a.  Convert heart rate to R-R:   

(in User's Mode) heart rate (bpm) ( D )

-or-

5b.  Convert R-R to heart rate:

(in User's Mode)  R-R ( D )

6.  Compute Q-T.  

(in User's Mode)  ( E )

HP 41C/DM41 Program:  EKG

01 LBL T^EKG

02 SF 27

03 GTO 00

04 LBL A

05 - 

06 STO 01

07 ^T III:_ 

08 ARCL X

09 AVIEW

10 RTN

11 LBL B

12 -

13 STO 03

14 RCL 01

15 +

16 STO 02

17 ^T II:_ 

18 ARCL X

19 AVIEW

20 RTN

21 LBL C

22 RCL 01

23 ENTER↑

24 0.5774

25 *

26 RCL 03

27 ENTER↑

28 1.1547

29 *

30 +

31 ENTER↑

32 RCL 01

33 R-P

34 X<>Y

35 57

36 -

37 ^T DEV=

38 ARCL X

39 AVIEW 

40 STOP

41 X<>Y

42 ABS

43 ^T MAG=

44 ARCL X

45 AVIEW

46 RTN

47 LBL D

48 ENTER↑

49 ENTER↑

50 60

51 X<>Y

52 /

53 X<=Y?

54 GTO 05

55 ^T RATE=

56 ARCL X

57 AVIEW

58 RTN

59 LBL 05

60 ^T R-R=

61 ARCL X

62 AVIEW

63 RTN

64 LBL E

65 X>Y?

66 X<>Y

67 SQRT

68 0.39

69 *

70 ^T Q-T=

71 ARCL X

72 AVIEW 

73 RTN

74 LBL 00

75 RTN

76 END

Example

I+ = 2.8 mm,  I- = 1.1 mm

III+ = 2.5 mm, III- = 1.4 mm

Heart Rate = 86 bpm

Keystrokes:

XEQ "EKG"

(User Mode is On)

2.8 [ENTER] 1.1 ( A ) 

Display:  III: 1.7000

2.5 [ENTER] 1.4 ( B )

Display:  II:  2.8000

( C )

Display:  DEV=-4.0516

[ R/S ]

Display:  MAG=2.8214

86 (D)

Display:  R-R=0.6977

(E)

Display:  Q-T=0.3258

Source:

"Basic EKG Determinations"  HP-67/97 User's Library Solutions:  Cardiac.  Hewlett Packard.  Corvallis, OR.  (no date given, but I estimate this to be circa 1974)

Eddie

All original content copyright, © 2011-2019.  Edward Shore.   Unauthorized use and/or unauthorized distribution for commercial purposes without express and written permission from the author is strictly prohibited.  This blog entry may be distributed for noncommercial purposes, provided that full credit is given to the author. 

DM 41L and HP 41C: Schur-Cohn Algorithm

DM 41L and HP 41C:  Schur-Cohn Algorithm

Introduction

The Schur-Cohn Algorithm tests whether the roots of a polynomial p(x) lies with in the unit circle.  That is for the polynomial p(x):

p(x) = a_0 * x^n + a_1 * x^(n - 1) + a_2 * x^(n - 2) + ... + a_n

For all the roots of p(x), r_0, r_1, r_2, ... , r_n ,   |r_k| < 1.    The test covers both real and complex roots.  Keep in mind that this test doesn't tell us what the roots are, only a clue to whether the roots lie in the unit circle or not.

The Schur-Cohn Algorithm returns the test answers b_0, b_1, etc.  If |b_k| < 1 holds true for each b_k for k = 0 to n, then we can conclude that |r_k| <  1.

The following program is adopted from Peter Henrici's book Computational Analysis With the HP-25 Pocket Calculator [Henrici, 111] for the HP 41C and the Swiss Micros DM 41L.  The program deals with polynomials up to the fourth order, but can be expanded on an RPN calculator with more program space and memory registers.

Instructions:

For the fourth order polynomial:

p(x) = a_0 * x^4 + a_1 * x^3 + a_2 * x^2 + a_1 * x + a_4

To the coefficients in the following registers:

R00 = a_0
R01 = a_1
R02 = a_2
R03 = a_3
R04 = a_4

The test results will pop momentarily during execution.  The program is done when after four test values, 4 is in the display.  The last test value is stored in R05.

DM 41L and HP 41C Program:  SCHUR (77 bytes, 11 registers of memory) 

01  LBL^T SCHUR
02  CLX
03  STO 07
04  LBL 03
05  STO 06
06  RCL 04
07  RCL 00 
08  /
09  STO 05    
10 PSE   // show test values
11 RCL 04
12  *
13 ST- 00
14 RCL 01
15 RCL 02
16 RCL 03
17 LBL 15
18 RCL 06
19 X=0?
20 GTO 24
21 RDN   // R↓
22 RCL 04
23 1
24 ST- 06
25 RDN
26 GTO 15
27 LBL 24
28 RDN
29 RCL 05
30 *
31 ST- 01
32 RDN
33 RCL 05
34 *
35 ST- 02
36 RDN
37 RCL 05
38  *
39 ST- 03
40 RCL 03
41 STO 04
42 RCL 02
43 STO 03
44 RCL 01
45 STO 02
46 RCL 00
47 STO 01
48 1
49 ST+ 07
50 4
51 RCL 07
52 X
53 GTO 03

Example

p(x) = 20 * x^4 - 16 * x^3 - 2 * x^2 + 2.08 * x + 0.21

Store the following values:
R0 = 20
R1 = -16
R2 = -2
R3 = 2.08
R4 = 0.21

Test Values:
0.0105
0.1124
-0.0090
-0.8074

For the record the roots of p(x) are 0.5, -0.1, 0.7, and -0.3.

This blog entry is not for use for commercial purposes.

Source:

Henrici, Peter.  Computational Analysis With the HP-25 Calculator  A Wiley-Interscience Publication. John Wiley & Sons: New York 1977 .  ISBN 0-471-02938-6

Eddie

Pi Day 2018

Happy Pi Day!  Here I am celebrating with a couple of 41s (Hewlett Packard HP 41C, Swiss Micros DM41L).

Happy Birthday Albert Einstein

RIP Stephen Hawking

π = 3.1415926535...

If you want to calculate many digits of pi, there are many ways to do this.  If you have a TI-89 or HP Prime, please check out this blog from November 2016: https://edspi31415.blogspot.com/2016/11/ti-89-and-hp-prime-approximation-digits.html

Happy Pi Day!

Eddie


This blog is property of Edward Shore, 2018

Review: SwissMicros DM41L

Review: SwissMicros DM41L

General Information

Company:  SwissMicros, https://www.swissmicros.com/

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).

Keyboard

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.

Connectivity

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:  https://www.swissmicros.com/instructions.php

Programming

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 (http://www.hpmuseum.org/forum/forum-11.html ), 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:  http://www.greendyk.nl/hp41c-manual/index.php?s=J&p=7  Special thanks to Greendyk!   ( www.greendyk.nl )

Verdict

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.

Eddie

This blog is property of Edward Shore, 2018.