John's Vademecum - public:calculator:guides

DM41X 41z Module

anonymous@undisclosed.example.com (Anonymous) — Tue, 17 Feb 2026 15:42:44 +0000

←Calculators

DM41X 41z Module

Keyboard Overlay

Setup

assign the complex keyboard Z i.e. function ΣZL to USER menu on key Σ+
- SHIFT ASN ALPHA SHIFT F Z L ALPHA Σ+
  - SHIFT F is the method of getting Σ from the ALPHA keyboard (see the back of calculator)
- Enter USER mode with USR key
- The Σ+ now activates a complex number function when it's pressed - for one operation only

The rest of the guide was written without the use of full-time ZKEYS in mind

in the forum thread dealing with the factorization bug in the deluxe version Angel recommended I use the ΣZL method. He fears that occasionally ZKEYS might be broken with incorrect/missing USER assignments - so I'll try to stick to the normal ΣZL method.

Quick Ref

Z = Σ+

↑IM/AG = Z XEQ
ZREAL↑ = Z Z RCL
ZIMAG↑ = Z Z XEQ
ZINV = Z 1/X
POLAR = Z Z R→P (i.e. 6)
RECT = Z Z P→R (i.e. 5)
ZCONJ = Z SHIFT CHS (complex conjugate)
Z ^ X = Z EEX
Z ^ 1/X = Z Z EEX (root(s) of complex number) : see Cubic Roots
- ZNXTNRT _ = Z Z SHIFT √x NEXT ROOT enter the root you want
ZWDOT = ZZ. : dot product of 2 vectors/complex numbers
ZWCROSS = ZZ2 : Magnitude of the Cross Product of 2 vectors/complex numbers (no sign)
ZWDET = ZZ7 : Determinant (Cross Product) of 2 vectors/complex numbers, incl. sign/direction

Basic Operation

enter two numbers and add them together

The ''natural'' entry method

Enter a complex number to the stack
- 5 + j 20
  - 5 Z XEQ 2 0 ENTER
    - Z XEQ is ^IM/AG - set the imaginary part
add a second number to the stack
- 10 - j 32
  - 10 Z XEQ 3 2 CHS ENTER
add the two numbers together
- Z +
15 - j 12

Enter a real number

2.75 + j 0
- 2.75 Z Z RCL

Enter an imaginary number

0 + j 3.1415 (i Pi)
- SHIFT π Z Z XEQ

Use it to calculate with....

calculate e^iπ
- Z SHIFT e^x
- - 1 + j 0
- e^iπ = -1

Parallel Impedances

This involves the complex inverse function Z 1/x

Z1 = 50 + j 13 in parallel with Z2 = 23 - j 85
- enter Z1 50 Z XEQ 13 ENTER and invert it Z 1/X
  - 0.02 - j 4.87E-3
- enter Z2 23 Z XEQ 85 CHS ENTER and invert it Z 1/X
  - 2.97E-3 + j0.01
- add them together Z +
  - 0.02 +j0.01 and invert Z 1/X
    - 42.72 - j 11.99

convert to Rectangular ⇔ Polar operation

Z = 50 - j 23
initially in rectangular form…¹⁾
- enter Z as usual
  - 50 Z XEQ 23CHS ENTER
- convert to Polar format
  - Z Z 6 ( 6 is R→P but needs two presses of Z to activate it)
  - 55.04 ∠ -24.70
- convert back to Rectangular operation
  - Z Z 5
  - 50 - j 23

enter a number directly in Polar format

To enter 5 ∠ 53.13 directly
- switch to Polar format Z Z 6
- enter Mag / Angle:
  - 5 Z XEQ 53.13 ENTER
  - display : 5 ∠ 53.13
convert to Rect
- Z Z 5
  - display : 3.00 + j 4.00

Cubic Roots

Rectangular

enter complex real number -8 + j 0
- 8 CHS Z Z RCL
  - -8 + j 0
- enter 3 (goes into the normal X register)
- find the result of Z↑1/x
  - Z ZEEX
    - 1 + j 1.732 (the first of the cube-roots of -8)
- find the next root with the function ZNXTNRT
  - Z Z SHIFT√x
  - enter 3 at the _ prompt
    - -2 + j 0
- find the next root with the function ZNXTNRT
  - Z Z SHIFT √x
  - enter 3 at the _ prompt
    - 1 - j 1.732

The 3 cube roots of -8 are

1 + j 1.732
-2 + j 0 (the basic real cube root)
1 - j 1.732

Polar

enter complex real number -8 + j 0
- 8 CHS Z Z RCL
  - -8 + j 0
  - convert to POLAR
    - Z Z6
      - 8 ∠ 180
- enter 3 (goes into the normal X register)
- find the result of Z↑1/x
  - Z Z EEX
    - 2 ∠ 60.000 (the first of the cube-roots of -8)
- find the next root with the function ZNXTNRT
  - Z Z SHIFT √x
  - enter 3 at the _ prompt
    - 2 ∠ 180
- find the next root with the function ZNXTNRT
  - ZZSHIFT√x
  - enter 3 at the _ prompt
    - 2 ∠ -60.000

The 3 cube roots (in POLAR) of -8 are

2 ∠ 60.000
2 ∠ 180
2 ∠ -60.000

Alternate input method

BEWARE

key Imaginary part first & press normal ENTER
key real part (and no ENTER)
do complex enter (Z ENTER) or another complex function (e.g. Z +) (be careful with the stack lift or it gets confusing)
e.g. 52 + j 36
- 36 ENTER 52 Z ENTER
- 52 + j 36 is now in Stack
enter second number
e.g. 23 - j 15
- 15 CHS ENTER 23 (don't Z ENTER this…!!)
to add them together use Z + now (instead of Z ENTER)
result : 75 + j 21

gotcha

pressing Z ENTER after the second number (instead of the required complex function) will give you

Stack value	Stack
	U
52 + j 36	V
23 - j 15	W
23 - j 15	Z

doing a Z + now will add the second number to itself and the result will be 46 - j 30

This is normal RPN stack behaviour, but is confusing when you're building complex numbers.

use ↑IM/AG instead

The natural entry mode is much better

you enter the real and imaginary parts in the order you expect them
the stack operation is less obscure.
It just seems more intuitive.

Page created Wed May 25 15:14:29 2022 by John Pumford-Green

Page last updated: 17/02/26 15:41 GMT

calculator, dm41x

¹⁾

Z Z 5 to make sure!

DM41X Advantage Pac

anonymous@undisclosed.example.com (Anonymous) — Sat, 07 Feb 2026 08:43:14 +0000

←Hints & Tips

DM41X Advantage Pac

The HP Advantage Pac module

Useful Functions

The Advantage Pac Module adds several features not normally found on the HP41.

The most useful to me are

MATRX : Simple square matrix “Simultaneous Equation” solutions
CFIT : Fitting data to various curves : LIN/LOG/E^x/Power
SOLVE and INTEGrate : similar to the HP15C/DM15L functions
PLY Polynomial Solver
Matrix (more extensive than the one above)
TVM : Finance calculations

Also available are

Complex Numbers
Number Bases and Boolean Logic

- these are better handled in the Angel Martin modules DM41X 41z Module and DM41X HP16C Module

These are less useful to me (at the moment)

Vector
Differential Equations
Co-ordinate Transformations

Flag 21

Remember to Clear FLAG 21 after using any Advantage Pac programs - by turning the DM41X OFF and ON again….

— John Pumford-Green 05/08/22 14:26

Further Information

calculator, dm41x

DM15L Non-linear Curve Fit

anonymous@undisclosed.example.com (Anonymous) — Mon, 06 Apr 2026 12:40:53 +0000

←Hints & Tips

DM15L Non-linear Curve Fit

Using DM15L/HP15C built-in L.R function to fit non-linear curves

Background

The idea is that the 3 different non-linear function forms can be expressed as linear expression y = m.x + c if we manipulate the x or y values before adding them to the statistics accumulator.

The different curves require different treatment of the data to linearize, and the resulting coefficients may require treatment too.

Tl;dr

Method for Exponential

y = b.e^ax

Ln(y) = a.x + Ln(b)

Enter Accumulation data	`y_i gLn x_i ∑+`
Calculate coefficients	`fL.R.e^x`
Estimate ŷ & r for a new `x`	`x fŷ.r e^x`

Method for Logarithmic

y=a.ln(x)+b

y = a.Ln(x) + b

Enter Accumulation data	`y_i Enter x_i gLn∑+`
Calculate coefficients	`fL.R.`
Estimate ŷ & r for a new `x`	`xgLn fŷ.r`

Method for Power

y=b.x^a

Ln(y) = a.Ln(x) + Ln(b)

Enter Accumulation data	`y_i gLn x_i gLn∑+`
Calculate coefficients	`fL.R.e^x`
Estimate ŷ & r for a new `x`	`x gLnfŷ.re^x`

Exponential

y = b.e^ax

This can be expressed as Ln(y) = Ln(b) + a.x

Ln(y) = a.x + ln(b)

compare with a linear expression y = m.x + c

Using Ln(y) and x as data points and running the L.R. function will give coefficients equal to a and ln(b)

You can obtain the actual value of b finding its antilog with e^x.

Once the L.R. has run you can find estimates of ŷ by running the fŷ.r to get the estimate of Ln(y) and then finding its antilog with e^x

Mechanism

To enter the data points you convert the y data to its Ln first, then accumulate as normal

y_i gLn x_i ∑+

Once all the data has been entered you get the Linear Regression coefficients a & b fL.R. and e^x to correct the b LR coefficient.

Example Data

y	2.8	3.6	5.8	8.0
x	0.8	1.1	1.7	2.1

fClear ∑

2.8 gLn 0.8 ∑+

3.6 gLn 1.1 ∑+

5.8 gLn 1.7 ∑+

8.0 gLn 2.1 ∑+

All data is in the accumulator, now do the Linear Regression fL.R.

This gives a and Ln b coefficients

Y: 0.805 = a

X: 0.3897 = ln b

so we need to find b so e^x

Y: 0.805 = a

X: 1.476 = b

Equation estimation is therefore y = 1.476 e ^0.805x

I made the data table by using the equation y = 1.5 e ^0.8x and then used approx. y values for the data table…. so the estimate looks pretty good

To do an estimation of y when x = 0.9

0.9 fŷ.r e^x

Y: 0.999962 = r correlation coefficient

X: 3.047425 = ŷ estimation

Method for Exponential

Enter Accumulation data	`y_i gLn x_i ∑+`
Calculate coefficients	`fL.R.e^x`
Estimate ŷ & r for a new `x`	`x fŷ.r e^x`

Logarithmic

y = a.ln(x) + b

Compare to a linear expression y = m.x + c shows the logarithmic curve is linear if we use Ln(x) as we accumulate data points.

The L.R. will provide the actual a and b coefficients.

To estimate ŷ first find the Ln of x then use the fŷ.r

Mechanism

y_i Enter x_i gLn∑+

Calculate LR Coefficients

fL.R.

Calculate estimated ŷ by finding the Ln of your x value first and then using fŷ.r

xgLnfŷ.r

Example Data

y	1.5	1.7	1.8	2.1
x	0.8	1.7	2.6	4.9

fClear ∑

1.5 Enter 0.8 gLn∑+

1.7 Enter 1.7 gLn∑+

1.8 Enter 2.6 gLn∑+

2.1 Enter 4.9 gLn∑+

Linear Regression Coefficients : fL.R.

Y: 0.324 = a

X: 1.544 = b

Equation y = 0.324 . Ln(x) + 1.544

Estimate ŷ for X = 3

3 gLn fŷ.r

Y: 0.985 = r, correlation coefficient

X: 1.900 = ŷ, estimation

Method for Logarithmic

Enter Accumulation data	`y_i Enter x_i gLn∑+`
Calculate coefficients	`fL.R.`
Estimate ŷ & r for a new `x`	`xgLn fŷ.r`

Power

y = b.x^a

This can be rearranged as Ln(y) = Ln(b) + a.Ln(x) or Ln(y) = a.Ln(x) + Ln(b)

Compare to a linear expression y = m.x + c

Our expression will be a straight line if we accumulate Ln(y) and Ln(x)

The coefficients given by the L.R. function will be a and Ln(b) - so to get the real b coefficient we find its antilog e^x

We get the estimate for ŷ we first find the Ln of our chosen x and then use the ŷ.r to get Ln(ŷ) and then e^x to get ŷ

Mechanism

Accumulate using

y_i gLn x_i gLn∑+

Calculate LR Coefficients

fL.R.e^x

Calculate estimated ŷ

xgLnfŷ.re^x

Example Data

y	1.3	2.2	3.3	4.4
x	0.6	1.3	2.4	3.6

fClear ∑

1.3 gLn 0.6 gLn∑+

2.2 gLn 1.3 gLn∑+

3.3 gLn 2.4 gLn∑+

4.4 gLn 3.6 gLn∑+

Linear Regression Coefficients : fL.R.e^x

Y: 0.678 = a

X: 1.837 = b

Equation : y = 1.837x^0.678

Estimate ŷ for X = 3

3 gLnfŷ.re^x

Y: 1.000 = r, correlation coefficient

X: 3.869 = ŷ, estimation

Method for Power

Enter Accumulation data	`y_i gLn x_i gLn∑+`
Calculate coefficients	`fL.R.e^x`
Estimate ŷ & r for a new `x`	`x gLnfŷ.re^x`

— John Pumford-Green 01/02/26 08:42 GMT

Further Information

calculator, dm15l

DM15L/41X/41L "Multi-Variable" Solve

anonymous@undisclosed.example.com (Anonymous) — Sat, 07 Feb 2026 08:53:34 +0000

←Hints & Tips

DM15L/41X/41L "Multi-Variable" Solve

Using multi-variable equations in SOLVE

Source

https://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/articles.cgi?read=556

In order to conveniently employ SOLVE or INTEG on the HP-34C/15C/41C for multiple-input, single-output (MISO) user-defined functions, the user's program should emulate the way SOLVE and INTEG manage input variables on the three Pioneer-series models and the HP-33s.

Assume that a MISO function is to be programmed as an RPN routine on a HP-34C, HP-15C, or HP-41C/CV/CX. A user may wish to use SOLVE or INTEG successively for any selected “focus” variable with all others held constant, and without having to edit the RPN routine. Here is a simple procedure for this purpose:

Choose a numbered storage register for each variable in the function. On the 41C/CV/CX, choose another numbered register as the indirect storage register. (Do not use a stack register, as it will be overwritten by SOLVE or INTEG.) In PROGRAM mode:

Program the function as an RPN routine that not only meets the basic requirements, but also retrieves each variable from its chosen storage register when it is used. (On the 41C/CV/CX, the label beginning the routine must be an external label.) The second instruction of the routine (immediately after LBL) should store the stack x-register value to the indirectly-referenced register. This instruction is “STO (i)” on the HP-34C and HP-15C; it is “STO IND nn” on the HP-41C/CV/CX. In RUN mode:

Store the desired constant values of the fixed-value variables to their storage registers. Store the register number containing the floating variable to the indirect storage register. Invoke SOLVE or INTEG in the usual manner. This procedure utilizes indirect storage to make the RPN program more flexible. SOLVE and INTEG feed the each value of the floating variable as input to the user program, which immediately stores the value indirectly to its user-chosen register. Each variable in the function is then recalled for use in calculations, so the user program need not be structured to receive any particular variable from the stack.
EXAMPLE:

f(x, y, z) = 2*x - ln y + 1/z

x in R1; y in R2; z in R3
indirect in R00 (HP-41 only)


HP-15C/HP-34C program:      HP-41C/CV/CX program:


LBL A                       LBL "AA"
STO (i)                     STO IND 00
RCL 1                       RCL 01
2                           2
*                           *
RCL 2                       RCL 02
LN                          LN
-                           -
RCL 3                       RCL 03
1/x                         1/x
+                           +
RTN                         RTN


In RUN mode, solve for x such that f(x, y=15.1, z=5.3) = 0


HP-15C/HP-34C:              HP-41C/CV/CX:


15.1                        15.1
STO 2                       STO 02
5.3                         5.3
STO 3                       STO 03
1                           1
STO I                       STO 00
0.5                         0.5
ENTER                       ENTER
5                           5
SOLVE A                     "AA"  (enter AA in alpha mode)
                            XEQ "SOLVE"


(Answer is 1.263007749)


Next, solve for y such that f(x=0.7, y, z=3.3) = 0


HP-15C/HP-34C:              HP-41C/CV/CX:


0.7                         0.7
STO 1                       STO 01
3.3                         3.3
STO 3                       STO 03
2                           2
STO I                       STO 00
0.5                         0.5
ENTER                       ENTER
6                           6
SOLVE A                     "AA"  (enter AA in alpha mode)
                            XEQ "SOLVE"


(Answer is 5.490560270)


Finally, integrate f(x=1.7, y=4.1, z) over z = 1.0 to 6.0.
Specify 5 decimal-digit absolute function accuracy:


HP-15C/HP-34C:              HP-41C/CV/CX:


FIX 5                       FIX 5
1.7                         1.7
STO 1                       STO 01
4.1                         4.1
STO 2                       STO 02
3                           3
STO I                       STO 00
1                           1
ENTER                       ENTER
6                           6
INTEG A                     "AA"  (enter AA in alpha mode)
                            XEQ "INTEG"


(answer is 11.73682)
https://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/articles.cgi?read=556

Example : OHMS LAW

from https://www.hpmuseum.org/forum/thread-1212.html

So, can I write an equation in programming, such as

(I* R) - E = 0

(or however one should program it in)

and use SOLVE to find the unknown?

Code:
LBL A
STO (i) 
RCL 0
RCL* 1
RCL- 2
RTN
Example:
<I> STO 0
<E> STO 2
1 STO I
SOLVE A
from https://www.hpmuseum.org/forum/thread-1212.html

Example : Nano-VNA TDR settings

F = (Points^2 x v.f x 0.284 ) / distance

Points → R01
Distance → R02
V.F → R03
Frequency → R04

LBL 71
Sto(i)
RCL 01
x^2
RCL* 03
0.284
*
RCL/ 02
RCL- 04
RTN

Example

Find the Frequency sweep width needed for a distance of 35m with the following settings:

Distance = 35m
Points = 101
V.F = 0.66

101 STO01
35 STO02
.66 STO03
4 STO I
solve 71

Result = 54.63MHz

— John Pumford-Green 02/08/22 11:50

Further Information

calculator, dm15l

DM15L Startup Keys & Serial Console

anonymous@undisclosed.example.com (Anonymous) — Sat, 24 Jan 2026 08:10:32 +0000

←Hints & Tips

DM15L Startup Keys & Serial Console

Start Keys

The DM15L has a few options which are set by holding certain keys at power on
In the Update from V33 onwards these settings can also be modified directly via the “Setup Menu”
- press fON then the key for the function as below….

Key	Function description
A	Display time/date for 5 minutes
B	Benchmark. Evaluate speed compared to original calculator
C	Switch to serial console
D	Start Bootloader
E	System info. Firmware version, battery voltage, CPU frequency, etc.
CHS	Change LCD contrast.¹⁾
EEX	Reset LCD contrast to default values.
STO	Adjust RTC: decrement -1h
RCL	Adjust RTC: increment +1h
7	Cycle through available fonts
1	One Line Display
2	Two Line Display
9	Configure CPU speed. Toggle between 12MHz and 48MHz
÷	Keyboard self test
⨯	Self test
−	Power reset
+	Endless test
.	Toggle decimal delimiter
SST	Time/date adjustment.²⁾
GTO	Toggle annunciator position

Serial Console

Settings

Speed : 38400
Data bits : 8
Stop bits : 1
Parity : None
Flow control : XON/XOFF (or none)

Commands

 
VOYAGER >> ?
Firmware DM15_M80_V32

?          Help
p          Key press
s          Dump memory
l          Load memory
ct         Console timeout
bootloader Invoke Bootloader
t          Get time
ts         Set time
td         Update time
kb         Toggle keyboard output to console
d          Toggle display output to console
b          Read battery voltage

Type '<command> ?' for params
VOYAGER >>

The calculator can be programmed using the dumps, via the Serial Console, by copy & paste of the text of dump using the Serial Console command l

An example session

Memory dump captured by Copy & Paste from the console session above.

DM15_M1B
00  03000007146000  03999994641000  03999994641000  00000000000000
04  49828382834000  00000000000008  0000000000000c  00002005999eae
08  00000000000000  39fa0ffffaea8f  dba083fce4bf80  00000000000000
10  00000000000000  00000000000000  00000000000000  05000000000000
14  f0000000000089  20323232323232  000000000001f2  00000000000000
18  00000000000000  0000000000007f  00000000a00000  05313010235001
1c  00000000000000  00000000000000  00000000000000  01844692622004
f0  00000000000000  00000000000000  000000000000b2  fdfbf132faf142
f4  ccfdf0f20cb2c3  fcf0f2bcfdfaf1  32fbf1420bb233  44fcc3f0f2bcfd
f8  faf133fbf143fd  a2cff182cff142  cafd0ab21282df  f1cafdf5c0f3fc
fc  31fd30fb31fc30  310241f5f4f3c0  f240f6c6f4f3f2  f1f0c0f142f00e
A: 49828382834000  B: 49828382834eae  C: 00002005999eae
S: 00000000001000
M: 01844692622004  N: 99828382834004  G: 06

This dump pasted into the Swiss Micro decoder

The decoded dump, showing the actual program commands

001  LBL E        | 42,21,15
002  0            |        0
003  STO 2        |    44  2
004  1            |        1
005  .            |       48
006  0            |        0
007  1            |        1
008  2            |        2
009  3            |        3
010  4            |        4
011  EEX          |       26
012  6            |        6
013  STO 0        |    44  0
014  2            |        2
015  .            |       48
016  3            |        3
017  4            |        4
018  5            |        5
019  STO 1        |    44  1
020  LBL 2        | 42,21, 2
021  RCL 1        |    45  1
022  RCL 0        |    45  0
023  *            |       20
024  RCL 1        |    45  1
025  -            |       30
026  RCL 0        |    45  0
027  /            |       10
028  RCL 1        |    45  1
029  *            |       20
030  3            |        3
031  .            |       48
032  5            |        5
033  /            |       10
034  sqrt         |       11
035  1            |        1
036  STO+2        | 44,40, 2
037  GTO 2        |    22  2
038  RTN          |   43  32
039  LBL A        | 42,21,11
040  /            |       10
041  sqrt         |       11
042  STO 2        |    44  2
043  1            |        1
044  RCL+2        | 45,40, 2
045  1            |        1
046  RCL-2        | 45,30, 2
047  /            |       10
048  STO 3        |    44  3
049  1            |        1
050  -            |       30
051  RCL 3        |    45  3
052  1            |        1
053  +            |       40
054  /            |       10
055  LOG          |   43  13
056  2            |        2
057  0            |        0
058  CHS          |       16
059  *            |       20
060  STO 4        |    44  4
061  RCL 3        |    45  3
062  RTN          |   43  32
063  LBL B        | 42,21,12
064  STO 2        |    44  2
065  1            |        1
066  -            |       30
067  RCL 2        |    45  2
068  1            |        1
069  +            |       40
070  /            |       10
071  LOG          |   43  13
072  2            |        2
073  0            |        0
074  *            |       20
075  CHS          |       16
076  RTN          |   43  32
077  LBL C        | 42,21,13
078  2            |        2
079  0            |        0
080  /            |       10
081  10^x         |       13
082  STO 2        |    44  2
083  1            |        1
084  +            |       40
085  RCL 2        |    45  2
086  1            |        1
087  -            |       30
088  /            |       10
089  RTN          |   43  32

Page created Thu May 26 17:41:19 2022 by John Pumford-Green

Page last updated: 24/01/26 08:10 GMT

calculator, dm15l

¹⁾

LCD Setting : Param1: up +, down −, Param2: up Σ+, down 3

²⁾

Date Adjustment Usage: Up +, Down −, Next ⨯, Prev ÷, ENTER to Set, ON to Cancel

DM16L Startup Keys

anonymous@undisclosed.example.com (Anonymous) — Mon, 08 Apr 2024 15:15:45 +0000

←Hints & Tips

DM16L Startup Keys

Start Keys

The DM16L has a few options which are set by holding certain keys at power on

Key	Function description
`A`	Display time/date for 5 minutes
`C`	Switch to serial console
`E`	System info. Firmware version, battery voltage, current frequency, etc.
`F`	Change LCD contrast.¹⁾
`BIN`	Reset LCD contrast to default values.
`STO`	Adjust RTC: decrement -1h
`RCL`	Adjust RTC: increment +1h
`7`	Cycle through available fonts
`9`	Configure CPU speed. Toggle between 12MHz and 48MHz
`÷`	Keyboard self test
`⨯`	Self test
`−`	Power reset
`+`	Endless test
`.`	Toggle decimal delimiter
`GSB`	Time/date adjustment.²⁾
`GTO`	Toggle annunciator position

Further Information

¹⁾

LCD Setting : Param1: up +, down −, Param2: up CHS, down 3

²⁾

Date Adjustment Usage: Up +, Down −, Next ⨯, Prev ÷, ENTER to Set, ON to Cancel

DM41X Catalogues

anonymous@undisclosed.example.com (Anonymous) — Sun, 07 Apr 2024 23:10:25 +0000

←Hints & Tips

DM41X Catalogues

What the different Catalogues show

SHIFT ENTER & enter the number of the catalogue. R/S to stop the auto-scrolling and use SST or ⇑ / ⇓ to step through the listing of items.

Catalogue 1 is User Programs
Catalogue 2 is External Functions
Catalogue 3 is Standard Functions
Catalogue 4 is Extended Memory Directory (is usually empty. After running Cat 4 the current free-size of extended memory is left in X)
Catalogue 5 is Alarms
Catalogue 6 is USR Keyboard assignments

Page created Wed May 25 16:57:27 2022 by John Pumford-Green

Page last updated: 08/04/24 00:10 BST

calculator, dm41x

DM41X Curve Fitting

anonymous@undisclosed.example.com (Anonymous) — Tue, 17 Feb 2026 15:48:49 +0000

←Hints & Tips

DM41X Curve Fitting

The Advantage Pac CFIT program requires all data values to be positive/non-zero

This is quite limiting and perhaps a better method is the PPC ROM's CV program.

CV does the same curve fitting (including selecting the best fit ) without this restriction for curves where negative co-ordinates are appropriate.

It also gives the function of calculating an estimated x value from an entered y, which CFIT doesn't do.

DM41X PPC ROM Curve Fit

Advantage Pac functions for statistical curve fitting.

CFIT program provides the functions to fit statistics data to LIN, Exp, LOG, Power and Best Fit

XEQALPHACFITALPHA

Save CFIT to a CST menu entry to make it easier to access

Clear Statistics Registers with C (CLΣ)
Enter Statistics in usual way with Y, ENTER, X, A(Σ+)
Don't use any data points ≤0
When all data pairs are entered press E (FIT)
Now choose which type of fit to use
- L = Linear
- LOG = Logarithmic
- Ex = Exponential
- P = Power
- B = Best Fit
R/S to cycle through the coefficients of the curve fit a, b, R^2 (error ratio)
You can next enter an x value to find the curve-fitted y value
pressing R/S can exit back to the Curves menu L LOG Ex P B to try a different fit to the same data
pressing R/S can exit back to the main menu to clear and enter a new set of data

Curve Fit values

Linear y = a + bx
Ex y = ae^bx
Log y = a + b ln(x)
Power y = a x^b

Example of a Best Fit (LOG)

X	0.72	1.31	1.95	2.58	3.14
Y	2.16	1.61	1.16	0.85	0.5

CFIT
CLΣ
2.16 ENTER 0.72 A (Σ+)
1.61 ENTER 1.31 A (Σ+)
1.16 ENTER 1.95 A (Σ+)
0.85 ENTER 2.58 A (Σ+)
0.5 ENTER 3.14 A (Σ+)
E (FIT)
E (B) best fit
display : LOG
R/S`
display : a = 1.8515
R/S`
display : b = -1.1021
R/S`
display : r^2 = 0.9893
R/S`
display : X=?
- enter an X value if wanted, to get a y
- 1.5 R/S
- display : Y=1.4046
- R/S`
- enter another, or press R/S again to exit to the curve fitting menu
try a different curve fit…. (L, Ex etc) or
R/S to exit to the top menu

the curve found is y = 1.8515 - 1.1021 ln(x)

— John Pumford-Green 31/07/24 14:46 BST

Further Information

calculator, dm41x

DM41X Ladybug Module

anonymous@undisclosed.example.com (Anonymous) — Mon, 12 Jan 2026 14:35:58 +0000

←Hints & Tips

DM41X Ladybug Module

Another HP16 emulation

Ladybug Key Overlay

Details

Ladybug is a more user-friendly, if less versatile, “HP16C programmer's calculator” module than the fully-featured HP16 module by Angel Martin. Both have their uses, but for a simple calculator for bit-banging while writing 6502 assembly code Ladybug does everything, with a less convoluted User Interface.

Although I also have a DM16L, the Swiss Micros modern clone of the original HP16C, I am finding that having Ladybug on the DM41X allows me to quickly switch between “normal” floating point calculations and integer “programming” calculations, and have access to the best of both worlds.

The DM16L/HP16C has very limited (basically unusable) floating point support.

The Ladybug module is more intuitive and usable than the Angel Martin HP16 emulator module and having Ladybug for INTEGER and the rest of the DM41X/HP41CX functionality for other tasks makes the DM41X my go-to calculator. The DM16L is fantastic as a single-minded programmer's calculator, and is used extensively when I'm engrossed in writing assembly code, but the DM41X is much more versatile and is carried with me at all times when I'm away from the workbench.

Launching

modules needed:
- Ladybug
- Boost
- OS/4

To switch to “Ladybug Integer” mode : XEQALPHAINTEGERALPHA

To leave (and return to normal mode) : XEQALPHAEXITAPPALPHA

Using the DM41X CST menu simplifies this, set 2 Custom menu entries for INTEGER and EXITAPP

Nice features

A “CMP” function akin to 6502 - sets flags in the same way but doesn't change the register(s)
Status Flags : C, Z, N and V equivalent to 6502 flags and set in the same way after various operations.
- Flag 0 = Zero Z
- Flag 1 = Sign N
- Flag 3 = Carry C
- Flag 4 = Overflow V
2's-complement mode is set with Flag 2
Leading Zeros display is set with Flag 5

Word Size is set with Shift+R/S
Windowing is selected with .
Bits can be set Shift+4, reset Shift+5 and tested Shift+6

Boolean Operations on values in X and Y registers
- AND Shift+1
- OR Shift+2
- XOR Shift+3

NOT Shift+CHS (invert each bit, on the value in the X register)

Shift and Rotate functions are conveniently accessible - see Overlay picture above - without delving into menus or launchers

— John Pumford-Green 23/09/22 13:40

Further Information

See DM41X Hits & Tips for idea on Module Switching

calculator, dm41x

DM41X Matrix

anonymous@undisclosed.example.com (Anonymous) — Sun, 08 Feb 2026 08:26:58 +0000

←Hints & Tips

DM41X Matrix

Matrix functions in the Advantage Pac

Background

The matrix functionality isn't a standalone program, with a menu, like CFIT and PLY.

It's a collection of individual programs that can be used for many matrix tasks. Each one has to be called individually as needed.

There are many commands, the most used are those for

Dimensioning a new matrix MATDIM
Editing a matrix to enter values - there are 2 versions
- Real Matrix MEDIT
- Complex Matrix CMEDIT
Inverting a matrix MINV
Transposing a matrix TRNPS
Finding the determinant MDET
Multiplying two matrices together M*M
Solving a system of equations defined by 2 matrices MSYS

Shortcuts to Matrix Commands

To make things easier it's best to use the DM41X CST custom command shortcut mechanism.

Start with a blank CST and add the commands you need. Then save this CST so that it's easy to switch to other CST setups, and then return to the Matrix setup later.

I have the following

A	`MATDIM`	I
B	`MEDIT`	J
C	`CMEDIT`	K
D	`MINV`	L
E	`M*M`	M	`ZK?YN`
F	`MDET`	N	`EMDIR`
G	`TRNPS`	O	`EMDIRX`
H	`MSYS`	P	`PURFL`

Matrices are saved in Extended Memory, and I put commands in CST to find and remove them once I'm finished: EMDIR, EMDIRX and PURFL and I have ZK?YN to quickly access DM41X 41z Module complex number functions (assuming the module is plugged-in).

Basic Workflow

All matrix addressing is done via the ALPHA register

Dimension a new Matrix

Put the name of the matrix in the ALPHA register.
- Use single letters A, B, C etc. - these will create the matrix in Extended Memory
- ALPHA A ALPHA
Put the dimensions in the X register
- this is in the form r.ccc with 3 decimal places for the column
- for a 3×3 : 3.003 (3 rows, 3 columns)
- for a 4×2 : 4.002 (4 rows, 2 columns)
- 3.003
  - puts the dimensions in the X register ready for MATDIM to assign to the matrix named in ALPHA
Execute the MATDIM command from the CST menu A
- CST A
- This creates matrix A in extended memory

Populate a new Matrix

Populate the matrix with values using MEDIT from the CST menu B

For a 3×3 matrix

| 1 1 -1 | | 4 6 6 | | 1 8 9 |

CST B
1:1= 1R/S
1:2= 1R/S
1:3= 1CHSR/S
2:1= 4R/S
2:2= 6R/S
2:3= 6R/S
3:1= 1R/S
3:2= 8R/S
3:3= 9R/S

Determinant

With A still in the ALPHA register use the MDET command from the CST menu F

CST F
-50.000

Matrix A will now be in LU Decomposition form.
It can be used in this form for some other functions, but it's possible to get it back to normal form by Inverting twice using MINV from CST menu D
- CST D
- CST D
- You can check the element values by using MEDIT again, but just cycling through each with R/S and not changing any values
  - it's possible to set flag 08 which prevents any changes to values

Multiplication

Using M*M

For matrix multiplication you need 3 matrix definitions:

Matrix A and Matrix B are the two matrices to be multiplied
- Matrix A and Matrix B are dimensioned with MATDIM and populated with MEDIT
Matrix C is the matrix to hold the result
- Matrix C is simply dimensioned with MATDIM and will be filled automatically by the function M*M

To multiply two matrices together they must have the correct dimensions

Columns in A must equal Rows in B
Results matrix C will have the dimensions Rows of A x Columns of B

Create Matrix A

Follow the same procedure as above.

Make sure ALPHA has only the letter A

A different numerical example

A will be a 3×2 matrix

use MATDIM via CST menu
- 3.002 CSTA

| 2 3 | | 4 5 | | 7 6 |

Use MEDIT via CST menu
- CST B
- 1:1= 2R/S
- 1:2= 3R/S
- 2:1= 4R/S
- 2:2= 5R/S
- 3:1= 7R/S
- 3:2= 6R/S

Create Matrix B

B will be a 2×2 matrix

Make sure ALPHA only has B and then dimension B with MATDIM from CST menu A

ALPHA B ALPHA
2.002 CSTA

| 2 3 | | 4 5 |

* Use MEDIT via CST menu

CST B
1:1= 2R/S
1:2= 3R/S
2:1= 4R/S
2:2= 5R/S

We now have defined the matrices to be multiplied together.

Create Matrix C

We need a results matrix C

The dimensions of C will be rows of A and columns of B which is 3 rows and 2 columns : 3.002

Make sure ALPHA only has C and dimension C with MATDIM from CST menu A

ALPHA C ALPHA
3.002 CSTA

That's enough to create the results matrix

Multiply the matrices

Put the matrix names in ALPHA in the form Matrix 1,Matrix2,Results Matrix
- ALPHA = A,B,C
ALPHA A , B , CALPHA
Execute M*M from the CST menu
- CST E
C will now hold the answer

View the result

Put C in the ALPHA register
ALPHA C ALPHA
Use MEDIT from the CST menu and cycle through the elements (it's a 3×2 matrix)
CST B
- 1:1= 16.000? R/S
- 1:2= 21.000? R/S
- 2:1= 28.000? R/S
- 2:2= 37.000? R/S
- 3:1= 38.000? R/S
- 3:2= 51.000? R/S

The result in C is

| 16 21 | | 28 37 | | 38 51 |

System of Equations

A simple example first

Set of Equations

3 unknowns

3x + 4y + 6z = 39.7 2x - 4y - 3z = -7.0 y + 8z = 63.4

Matrix representation

Matrix A

| 3 4 6 | | 2 -4 -3 | | 0 1 8 |

Dimensions 3.003

Matrix B

| 39.7 | | -7.0 | | 63.4 |

Dimensions 3.001

Simultaneous Equations represented in Matrix Form

|A| x |C| = |B| | 3 4 6 | | x | | 39.7 | | 2 -4 -3 | x | y | = | -7.0 | | 0 1 8 | | z | | 63.4 |

Create Matrix A

ALPHA A ALPHA
3.003 CST A (MATDIM)
CST B (MEDIT)
- 1:1= 3 R/S
- 1:2= 4 R/S
- 1:3= 6 R/S
- 2:1= 2 R/S
- 2:2= 4 CHS R/S
- 2:3= 3 CHS R/S
- 3:1= 0R/S
- 3:2= 1R/S
- 3:3= 8R/S

Create Matrix B

ALPHA B ALPHA
3.001 CST A (MATDIM)
CST B (MEDIT)
- 1:1= 39.7 R/S
- 2:1= 7 CHS R/S
- 3:1= 63.4 R/S

Run MSYS

Put A,B in ALPHA
- ALPHA A , B ALPHA
Run MSYS - the solution matrix for x, y and z will be placed in Matrix B
- CST H

Examine Matrix B

Put B in ALPHA
- ALPHA B ALPHA
Run MEDIT from CST menu
- CST B (MEDIT)
  - 1:1= 1.500 'R/S/
  - 2:1= -3.800 R/S
  - 3:1= 8.400 'R/S

The solution

x = 1.5 y = -3.8 z = 8.4

Matrix A

A is now in LU-decomposed format
It can be restored to normal by Inverting Twice
Put A in ALPHA
Run MINV via CST menu twice
- CST D CST D
A is now back to normal and can be inspected and edited by MEDIT via the CST menu

Another way to solve a system

Instead of the MSYS function you could do it manually by entering Matrix A and Matrix B, and define Matrix C such that

A X C = B

C = B / A

C = A* X B where A* is Inverse A

Create Matrix C with dimensions 3.001 in the usual way then and do:

Put A in ALPHA
Invert A using MINV from CST menu (A is replaced by its inverse)
Put A,B,C in ALPHA
Multiply using M*M
- this multiplies B by the inverse of A which is effectively dividing B by the original A
C now contains the solutions for x, y and z
Put C in ALPHA
Examine C with MEDIT
- 1:1= 1.500 R/S
- 2:1= -3.800 R/S
- 3:1= 8.400 R/s
This preserves B unlike the MSYS method.
The Inverse of A can be reversed by repeating MINV with A in ALPHA
We can even run M*M on A and C to re-create B
- Put A,C,B in ALPHA
- Run M*M from CST menu
- B will be re-created

The Complex Matrix

It is possible to define, edit and carry out operations with matrices containing Complex Numbers.

The matrix is defined with twice as many rows and columns as appears necessary, and edited with the function CMEDIT, in CST menu C

Example Definition

| 1+j2 5+j6 | | 3+j4 7+j8 |

Two rows and two columns 2×2 containing complex numbers, so the definition/dimension is 4.004

The numbers are actually saved as if in a larger real matrix as

| 1 -2 5 -6 | | 2 1 6 5 | | 3 -4 7 -8 | | 4 3 8 7 |

The entry is via CMEDIT via CST menu C, which asks for each Real and Imaginary part in turn

ALPHA A ALPHA
4.004 CST A
CST C
- RE. 1:1= 1 R/S
- IM. 1:1= 2 R/S
- RE. 1:2= 5 R/S
- IM. 1:2= 6 R/S
- RE. 2:1= 3 R/S
- IM. 2:1= 4 R/S
- RE. 2:2= 7 R/S
- IM. 2:2= 8 R/S

Multiplication of Complex Matrices

Create a second matrix

Matrix B of size 2×1 which can be multiplied by A as A x B

| 3+j4 | | 2+j6 |

Dimension second matrix

This is dimensioned as double the basic size of 2×1 : 4.002 and then populated with CMEDIT

ALPHA B ALPHA
4.002 CST A
CST C
- RE. 1:1= 3 R/S
- IM. 1:1= 4 R/S
- RE. 2:1= 2 R/S
- IM. 2:1= 6 R/S

Create a result matrix

Matrix 'C' which will be also be a 2×1 complex with dimension :4.002

ALPHA C ALPHA
4.002 CST A

Multiply A X B = C

ALPHA A , B , C ALPHA
CST E

Inspect Result Matrix C

ALPHA C
CST C
- RE. 1:1= -31.000 R/S
- IM. 1:1= 52.000 R/S
- RE. 2:1= -41.000 R/S
- IM. 2:1= 82.000 R/S

The result matrix is therefore

| -31+j52 | | -41+j82 |

Which agrees with my long-hand calculation (thanks to DM41X 41z Module )

|(1+j2).(3+j4) + (5+j6).(2+j6)| |(3+J4).(3+J4) + (7+J8).(2+J6)|

| (-5+j10) + (-26+j42) | | (-7+j24) + (-34+j58) |

| -31+j52 | | -41+j82 |

Systems of Complex Equations....

Once you can enter and manipulate Complex Matrices you can also use MSYS to solve systems with complex matrices in the same way as usual - the only difference is entering the matrices as Complex.

Clearing Up Extended Memory

After creating and manipulating (and some finger trouble) there will be a bunch of files in Extended Memory.

Most will be simple matrix definitions with obvious names A, B, C etc. but occasionally you'll accidentally have run MATDIM with some nonsense in the ALPHA register and created a nonsensical filename in extended memory, which it's tricky to spell out correctly in ALPHA in order to run PURLF - this is where EMDIRX comes in.

To simplify clearing up I include EMDIR, EMDIRX and PURFL in the CST menu.

Assuming you have other files in Extended Memory, the quickest way is to find the number of files in EM with EMDIR.

Run EMDIR from CST menu
- CST N
Count the files to find the number of the first file you've created using MATDIM - i.e. the first one after your other EM files
Put this number in x
Run EMDIRX from CST menu
- CST O
- this puts the name of the specified-numbered file in ALPHA and means you don't have to type it in yourself
Run PURFL from CST menu to delete this filename
- CST P
Run EMDIRX again (with the same number in X)
- If X returns as non-zero we've found another junk-matrix file in EM and ALPHA will have its name
- Run PURFL again
Keep doing this until EMDIRX returns 0.00 in X which means there are no more files to delete
- all your original files are still safe, as they are numbered below the number we were searching for

Further Information

calculator, dm41x

DM41X PPC ROM Solve & Integrate

anonymous@undisclosed.example.com (Anonymous) — Tue, 17 Feb 2026 07:59:17 +0000

←Hints & Tips

DM41X PPC ROM Solve & Integrate

Solve (SV)

Similar to other Solvers (e.g. the Advantage Pac Solve) but with some minor differences to be aware of.

ASTO the Global Label (name) of the program (in this example it's LBL AA) containing the expression to be solved in Register 06
- ALPHAAAALPHA
- XEQALPHAASTOALPHA06
The program with the expression to be solved must be written as though unknown x is on the x-stack only
- other solvers “fill the stack” with x
- here you need to manipulate the stack to get x as needed. It's easiest is to just ENTER ENTER ENTER and then treat the stack the same as other solvers (i.e. as if it's filled with x and you use x<>y to pull a fresh copy of x as needed in the expression).
Put a “step size” in y and a “start value” in x (e.g. -3)
- 0 ENTER -3
run SV

example

2x² + 3x - 4 = 0

Prog “AA”

LBL AA
ENTER
ENTER
ENTER
x^2
2
*
x<>y
3
*
+
4
-
RTN

for the first root

0 ENTER 1
XEQALPHA SV ALPHA

and the answer comes…..

0.850781059

for the second root

0 ENTER -3
XEQALPHA SV ALPHA

and the answer comes…..

-2.350781060

Integrate (IG)

This is very similar to SV - the main difference is that the Global Label for the program containing the expression to be integrated is stored with ASTO in Register 10.

I'm using AA as a general scratchpad Program label for use with Solve and Integrate…

ALPHAAAALPHA
XEQALPHAASTOALPHA10

For SV it's R06.

Otherwise carry out the same procedure for storing the expression.

Time taken for integration, and the accuracy obtained, is set by the display format - the more digits the longer the integration takes.

Set SCI 04 for most cases.

Set the name of the prog. in Reg 10
Edit the prog. for the expression to be integrated
Set the display format/accuracy to SCI 04
The limits of integration are set
- lowerENTER upper
Then the IG routine is executed
- XEQALPHAIGALPHA

Further Information

DM41X Solve

anonymous@undisclosed.example.com (Anonymous) — Sun, 18 Jan 2026 15:59:28 +0000

←Hints & Tips

DM41X Solve

Advantage Pac solver

Advantage Pac Solver

The Advantage Pac has a solver function which can find the roots of polynomials. The function to be solved is written as a normal keystroke program and then SOLVE uses it to find the roots.

To set it up

Write the program that defines the function to be solved
Put the Global Label of that program in the ALPHA register
Put estimates/range values in the y and x stack
Excecute solve

Example

— John Pumford-Green 17/01/26 18:28 GMT

Further Information

calculator, dm41x

DM41 Save/Restore Statistics

anonymous@undisclosed.example.com (Anonymous) — Tue, 10 Feb 2026 18:01:25 +0000

←Hints & Tips

DM41 Save/Restore Statistics

Using Extended Memory to save Statistics Registers

Background

Statistics use 6 regular registers to keep track of data for calculating Mean and Standard Deviations.

Keeping a long-term record of a set of variables means not being able to use the Statistics functions for anything else unless steps are taken to save and restore the registers.

It is possible to save the 6 registers in a data file in Extended Memory and then use the statistics for other things, and restore the saved Statistics back to Main Memory when required.

By Default the Statistics registers start at R11 but this can be changed with the command ∑REG

This is the default list of Statistics Registers and contents

R11	∑x	Summation of x-values
R12	∑x²	Summation of squares of x-values.
R13	∑y	Summation of y-values.
R14	∑y²	Summation of squares of y-values.
R15	∑xy	Summation of products of x- and y-values.
R16	n	Number of data points accumulated.

Advantage Pac : CFIT application seems to reset ∑REG to 12

Extended Memory Data File

The statistics registers use 6 Main Memory registers, usually R11 → R16

We need to create a Data File in Extended Memory to hold these.

Put the name in ALPHA e.g. REGS
Put 6 in x register
excecute CRFLD to create the Data File REGS in Extended Memory

Once it's created it can be used to hold the contents of the 6 Statistics Registers

Save Registers to Extended Memory

We need to make sure our Data File is the current file and that the pointer is at the beginning of the file
- Put REGS in ALPHA
- Put 0 in X so that we put the pointer at the first register record in the data file.
- Execute SEEKPTA
Now we need to copy the 6 Registers R11 → R16 to the Data File REGS
- ensure REGS is still in ALPHA
- put a number in X to indicate which range of Registers to save, this is bbb.eee where b is the beginning register and e is the end
  - put 11.016 in X
- execute SAVERX

Restore Registers from Extended Memory to Main Memory

We need to make sure our Data File is the current file and that the pointer is at the beginning of the file
- Put REGS in ALPHA
- Put 0 in X
- Execute SEEKPTA
We can copy the 6 registers held in the Data File REGS back to R11 → R16
- ensure REGS is still in ALPHA
- put a number in X to indicate where the recovered registers will be put in Main Memory
  - put 11.016 in X
- execute GETRX

A program to make it easier

It is possible to change the base register of the 6 Statistics Registers, away from the default of R11.

We need to take this into account.

This uses the query ∑REG? to find the base register, then create bbb.eee using simple arithmetic.

When used in SAVER (saveRegs) we ensure we copy the current Statistics Registers data.

When used in GETR (getRegs) we ensure we restore our data to the Registers currently set to be the active Statistics Registers (they may have changed since first saving them)

LBL ¬SAVER
¬REGS
0
SEEKPTA
∑REG?
1.001
*
.005
+
SAVERX
¬REGS SAVED
AVIEW
PSE
CLD
RTN
LBL ¬GETR
¬REGS
0
SEEKPTA
∑REG?
1.001
*
.005
+
GETRX
¬REGS OK
AVIEW
PSE
CLD
RTN

Multiple Saved Files

It's possible to have more than one Extended Memory file with Stats registers.

This could keep track of different sets of statistics and allow restore, update, save for many sets of statistical data.

I've set up two data files : REGS and CHESS in extended memory and made two version of the simple program above, the only change is to alter the lines which put the name of the file in ALPHA

Then I thought of adding a 7th Register holding the DATE of the latest SAVE for the CHESS statistics, so I can keep track of whether I'm up to date in entering the scores.

Delete the original CHESS Data File & make a new one with 7 registers

ALPHA → CHESS
execute PURFL
X = 7
ALPHA still → CHESS
execute CRFLD to create the new 7-register data file

The date is automatically stored in the register just after the Stats - in general in R18 when ΣREG is 12 - and automatically adapts the register used depending on ΣREG?

Here is SAVEC and GETC for saveChess and getChess

LBL ¬SAVEC
¬CHESS
0
SEEKPTA
∑REG?
STO 01
6
+
STO 00
DATE
STO IND 00
RCL 01
1.001
*
.006
+
SAVERX
¬CHESS SAVED
AVIEW
PSE
CLD
RTN
END

LBL ¬GETC
¬CHESS
0
SEEKPTA
∑REG?
STO 01
6
+
STO 00
RCL 01
1.001
*
.006
+
GETRX
CLA
RCL IND 00
¬LAST 
ADATE
AVIEW
PSE
CLD
RTN
END

Further Ideas

I might make a better version which prompts for a Data File name rather than having one separate program for each scenario

calculator, dm41x, dm41l

DM41X Hints & Tips

anonymous@undisclosed.example.com (Anonymous) — Sat, 24 Jan 2026 08:09:46 +0000

←Hints & Tips

DM41X Hints & Tips

Module Switching

Using the Ladybug module for Integer/Base calculations means it's impossible to also have the 41Z complex number module or the HP16C simulator module and the necessary library “plugged in” at the same time. There is a clash between Library 4 needed for 41z (and also needed for 16C) and OS/4 which is needed for Ladybug.

I've used the DM41X “module save/load” function to have different module-plugged states:

41z.m41 : with 41Z 2×2 Deluxe and Library 4 modules active
16c.m41 : with HP16 C Simulator and Library 4 modules active
lady.m41 : with Boost, OS/4 and Ladybug modules active
adv.m41 : with Advantage Pac module active

These are accessed via setup → 2. Module → 4. Load Modules → 1. Load AM list

Choosing the required *.m41 file will automatically unplug/plug whichever modules were active when the config. was saved.

This makes it easier to remember which supporting library/module are needed to use each particular module's functions.

It's possible to also save the flash state - which modules have been pre-loaded into the DM41X's Flash Memory making them available to be plugged in using different options at the setup 2. Module choices…. you'll work it out.

Advantage Pac : Flag 21

I found that using some of the Advantage Pac programs (e.g. MATRX or CFIT) would lead to AVIEW instructions in programs run subsequently to cause a HALT - requiring use of the R/S key.

I was told via a question on the Swiss Micros Forum that this was likely to be due to the Advantage Pac setting FLAG 21 (printer active) to help in its own presentation of information on the display.

FLAG 21 SET while FLAG 55 is CLEAR (since there's no Printer Module active) causes AVIEW instructions to halt awaiting user intervention (R/S key)

To restore things to normal : either CLEAR Flag 21 via CF or simply turn the calculator off and on again.

See APPENDIX D in the HP41CX User Manual Volume 2 for a better explanation of the use of Flag 21 to control AVIEW behaviour.

Extended Memory

Copy a program to Extended Memory:

Put Prog's name in Alpha register
XEQ storep
The prog remains in main memory but can be deleted (CLP) if memory needed
To restore to main memory put name in Alpha and then XEQ GETSUB

DDAYS

To find the number of days between two dates

enter 1^st date into Y-stack as dd.mmyyyy
key in 2^nd date into X-stack as dd.mmyyyy
XEQ ALPHA D D A Y S ALPHA
result is the difference in days.
DDAYS can be added to the CST program chooser to make it easier if multiple calculations are required

Example

Days between 27/2/66 and 31/5/22

27.021966 ENTER 31.052022 XEQ ALPHA D D A Y S ALPHA

Result = 20,547

Check :

365 ÷

Result 56.293

I'm 56 and a bit… sounds right…

XYZALM

Various Alarm functions

Put any message for the Alarm into the ALHPA register

Load the stack registers with:

Z : Repeat Interval HHHH.MMSSs or 0
Y : Date DD.MMYYYY or 0
X : Time HH.MMSSs

Execute XYZALM to set the alarm

When alarm goes off it is acknowledged by pressing any key except STO.

Acknowledging a non-repeating (i.e. Z was 0) alarm cancels it.
Acknowledging a repeating alarm cancels it and re-arms it, adding the Repeat Interval to create the new alarm time.
Pressing STO cancels the alarm but makes it a PAST DUE alarm.

Example

Set alarm for 22:20, today, not repeating, called Supper

ALPHA S U P PER ALPHA
0 ENTER (for Z = repeat interval)
0 ENTER (for Y = Date = Today)
22.20 XEQ ALPHA X Y Z A L M ALPHA

At 22:20 the alarm is activated. ALPHA shows SUPPER.

Alarm is cancelled by pressing any key but STO

Pressing STO creates a PAST DUE alarm which means it gets re-triggered if the calculator is turned off. It can be cancelled and deleted by pressing any key (except STO) and then the calculator will turn off. Pressing STO will create a new Past Due alarm, and allow the calculator to turn off. On turn on the Past Due alarm will still exist and turning off will trigger it again.

A Past Due alarm is useful to remind you that something happened previously and turning the calculator off is a memory-jogger.

CATALOGUE 5 R/S and ⇑ ⇓ steps through all alarms.

To clear an alarm from the Catalogue: SHIFT C ( where C is √ on top row )

— John Pumford-Green 31/05/22 13:13

Page last updated: 24/01/26 08:09 GMT

calculator, dm41x

DM41X HP16C Module

anonymous@undisclosed.example.com (Anonymous) — Tue, 10 Feb 2026 16:15:00 +0000

←Hints & Tips

DM41X HP16C Module

Keyboard Overlay

Background

The HP16C Programmer's Calculator is made for manipulating numbers in Binary/Octal/Hexadecimal/Decimal to help with programming and other areas that rely on the nitty-gritty of bit-twiddling.

Swiss Micros make a modern hardware emulation (similar in form to the DM15L I already own) but rather than adding another calculator to my (growing) collection I found there is a ROM/Module method to add all (and more) the same features to the DM41X (and presumably the HP41, if you can find a hardware ROM plugin with it).

I occasionally need to do some conversions/calculations into Hex and Binary (thinking of TCP/IP networking, subnet masks etc. or perhaps debugging RS232 serial data, or when writing rig control software?) and being able to do everything on the DM41X (along with the Complex Number module) means the DM41X will become even more useful day-to-day.

The manual for the HP16C Module hp_16c_emulator_manual.pdf

The versions of modules I'm using : hp-16c_rev.1a.zip

The HP16C

The HP16C Manual : https://literature.hpcalc.org/community/hp16c-oh-en.pdf

The DM16L

https://www.swissmicros.com/product/dm16l

I bought a DM16L in August 2022

Basic Operation

Like the 41Z Complex Number module, a USER keyboard assignment is made to a trigger command which then automagically re-maps the whole keyboard for one command, then it reverts to normal. A mental image of the re-mapped keyboard starts to develop with use, making operation easier with time.

I've assigned the LN key to the trigger command 16C for the USER keyboard

SHIFT ASN ALPHA SHIFT 1 SHIFT 6 C ALPHA LN

User Keyboard comments

With USER keyboard active I generally won't miss the loss of LN as I rarely use it.

If I do need LN I can simply turn off the USER keyboard.

The same applies for using the ∑+ key for entering Statistical Data - it's assigned to the Complex Keyboard trigger ΣZL.

I won't ever be using statistics at the same time as complex numbers (or HP16C functions).

The USER keyboard can generally remain active all the time except when I want to do statistics or calculate a natural logarithm. Two easy sacrificed keys. Are there others I can do without for additional assignments to frequently used functions or modules?

I've noticed that it's possible to assign the 16C command to the ∑+ key.

This allows a single key to be used both to trigger 16C mode, and then to trigger input mode 16NPT.

It means less hopping around.

The ∑+ key is doing double duty but ∑+ ∑+ seems a little more user friendly than LN∑+ for inputting numbers.

SHIFT ASN ALPHA SHIFT 1 SHIFT 6 C ALPHA ∑+

16KEYS?

16KEYS? info

I played with the LADYBUG module recently ( see DM41X Ladybug Module ) and enjoyed the more “immediate” keyboard input - with the whole keyboard re-mapped while using the module (in “INTEGER” mode). No need to preface each instruction with a trigger to enable the special keyboard for one command at a time.

I found that the HP16C Module can be switched to “full-time” 16KEYS mode too….

You need to get to the ∑BITS launcher and then select Y (for 16KEYS) and answer Y or N.

The 16KEYS function can't be reached any other way, that I've found. The simplest way is to use the DM41X CST menu to run the 16C ∑MOD launcher, then press SHIFT to switch to the ∑BITS launcher, then select Y (for 16KEYS).

You'll need to enable USER key mode, and then the 16C module can be used without the the need to trigger every command with 16C (normally ASN'd to LN key).

You still need to use 16NPT to input numbers (this is mapped to the A (∑+) key. Otherwise most things are just more intuitive. No need to use 16C before an arithmetic operation like + or - etc.

Example

Switch to BIN view

B

Enter a binary number 10111011

16NPT10111011ENTER

Convert to HEX

E

H: bb

Convert to DEC

D

d: 187

Enter a Decimal Number 23

16NPT23ENTER

d : 23

Add them

+

d: 210

Convert to BIN

B

b: 11010010

Much more intuitive….

Select the Base

USER keyboard active.

16C is USER assigned to LN - referred to as 16C hereafter.

I'll use the alpha letter for the top-row keys to describe them for Base Selection

16C B = BINARY

16C C = OCTAL

16C D = DECIMAL

16C E = HEX

Enter a number

HEX

Enter HEX value 5F

Use the 16NPT function which lives on the Σ+ button (it switches from the complex assigned ΣZL to 16NPT when the 16C is invoked)

16C E (to get into HEX mode)

16C 16NPT 5 F ENTER

Convert to BIN

16C B gives 1011111

Enter a new BIN number

16C 16NPT (i.e. Σ+) 1101100 ENTER

Add them together

16C + gives 11001011

Convert to HEX

16C E gives Cb

Convert to DEC

16C D gives 203

always enter numbers with 16C 16NPT the number ENTER

always use the 16 versions of mathematical functions

16C +

16C X

etc.

NOT, OR, AND, XOR

These are on shifted (and triggered with 16C) math keys:

- = NOT

+ = OR

x = AND

÷ = XOR

Example, in binary….

AND two numbers:

11011101 AND 10001001 →

16C B (to get into Binary mode if needed)

16C 16NPT 11011101 ENTER

16C 16NPT 10001001 ENTER

16C SHIFT X gives 10001001

In HEX…. XOR →

16C E (to get into HEX)

16C 16NPT BEEF ENTER (first number) (make sure at least 16-bit word size for this example Word Size

16C 16NPT CAFE ENTER (second number)

16C SHIFT ÷ (XOR) gives 7411

Convert answer to DEC

16C D gives 29713

Convert answer to BIN

16C B gives a long string of 1 and 0 that scroll across the screen…

Window

View the long BIN number using a WINDOW to look at 8 bits at a time…

16C SHIFT R/S

This asks WINDOW _ and enter 0 for the 1^st (MSB) 8 bits:

W0: 11101000:b

Scroll to sequential WINDOW slices with + and - →

+ →

W1: 0010001:b

+ →

W2: :b

The full 16-bit number is therefore:

111010000010001

Setting Word Size and negative number convention

The word size can be up to 64 bits. In general most stuff is 4, 8 or 16 bits wide, so you can set the size of the binary number in the ∑MOD launcher:

16C USR (one of several different ways of getting to ∑MOD)

16KEYS methods

There is then a choice of settings

B:O:D:H:F - 0: 1:2:W:S:?

The first four can set the mode to Binary, Octal, Decimal, Float.

0 sets UNSIGNED integers
1 sets ONE'S COMPLEMENT
2 sets TWO'S COMPLEMENT

Word size is checked with S

Word size is set with W then enter (eg) 16 to set 16-bit words.

Word Size can also be set directly from a 16C keyboard function 16WSZ accessed via 16C SHIFT 5 rather than via the ∑MOD menu/launcher

? displays the current settings (press ? then quickly press and hold it to read the displayed info)

0c - 16 - DEC

This means unsigned integers, 16-bit words, DECIMAL mode.

Other Launchers

Lots of functions are available in launcher sub-menus, eg a menu of rotate functions, or shift functions.

The various launchers are available cyclically via the 16C XEQ along with SHIFT and A

Some trial and error is needed to find what you want, but it starts:

16C XEQ → R: L LN RN R which is a menu to do bit-rotations.

Rotate 1-bit Left by pressing top-row button B

Rotate N-bits left with top-row button C (and enter the number of bits)

Rotate N-bits Right with top-row button D (and enter the number of bits)

Rotate 1-bit Right with top-row button E.

From the R menu:

A give the S: L LN RN R menu to SHIFT bits Left or Right

From the S menu:

XEQ gives ∑R : …………………. which gives lots of options to do things rightwards with the bits. list them

This goes on via XEQ and SHIFT (ORANGE button) to access several menu launchers. Trial and Error and muscle memory.

A brief map/list of launchers

16CXEQ → ∑ROT

∑ROT → XEQ → ∑LEFT → XEQ → ∑MOD → XEQ → ∑ROT

∑ROT → A → ∑SHF

∑SHF → XEQ → ∑RIGHT → XEQ → ∑BIT → XEQ → ∑SHF

∑LEFT ↔ SHIFT ↔ ∑RIGHT

∑MOD ↔ SHIFT ↔ ∑BIT

∑SHF ↔ SHIFT ↔ S“:

∑ROT ↔ SHIFT ↔ RC:

Registers etc

Numbers can be saved in 16C registers via 16C STO NN

e.g. save a subnet mask of 11111100 into 16C REG 00 (i.e. the last octet of a /30 network 255.255.255.252)

16C B (go to BINARY mode)

16C 16NPT 11111100 ENTER 16C STO 00

Use the stored value

What is 123 AND MASK ? (what's the network base number for host address of 123 using a netmask of 252?)

16C D (decimal so you can enter 123 rather than a BINARY number)

16C 16NPT 123 ENTER

recall mask (it doesn't matter that it was initially stored as a BINARY number, it's displayed in whatever base you are currently using)

16C RCL 00

AND them

16C SHIFT x

answer is 120

The MASK is still in 16-Register 00 if needed again….

Net address of a host with address 43?

16C D

16C 16NPT 43 ENTER

16C RCL 00

16C SHIFT x

answer : 40

xxx.xxx.xxx.43 has a network address of xxx.xxx.xxx.40

Most Used Functions

16C = LN (i.e. E on top-row)

16NPT = ∑+ (i.e. A on top-row, must be triggered with 16C) ²⁾

16C 16NPT type in a number ENTER (enter a number in whatever base is currently selected)

BIN OCT DEC HEX = 16C then one of top-row buttons B, C, D, E (select the required base)

∑MOD = 16C USR …. or 16C SHIFT 2 (open a settings menu to set the choice of mode/word/signed)

NOT / OR / AND / XOR = 16C SHIFT then one of - + x ÷ (logic functions)

RL / RR = 16C then one of SIN or COS (rotate Left or Right 1-bit)

RLN / RRN = 16C SHIFT then one of SIN or COS (rotate Left or Right N-bits _ _)

SLN = 16C TAN (shift Left N-bits _ _)

SRN = 16C SHIFT TAN (shift Right N-bits _ _)

Sb = 16C SHIFT 7 (set a bit _ _)

Cb = 16C SHIFT 8 (clear a bit _ _)

B? = 16C SHIFT 9 (is a bit _ _ set or not?)

#BITS = 16C SHIFT ∑+ (i.e. A on top-row) (how many bits are high?)

See Keyboard Overlay Pic above for more hints on 16C key assignments

EVERYTHING STARTS WITH ''16C''

It is recommended to change the assigned key occasionally to prevent wearing it out…..

DM41X MATRX Simultaneous Equations

anonymous@undisclosed.example.com (Anonymous) — Mon, 08 Apr 2024 10:50:33 +0000

←Hints & Tips

DM41X MATRX Simultaneous Equations

Advantage Pac Matrix manipulaltions (simple version)

Background: MATRX function

The Advantage Pac has quite extensive Matrix handling functions, mostly beyond anything I ever would need….

The simple MATRX program allows the entry of a square matrix (real or complex), and can calculate the INVERSE and DETERMINANT of it.

The square matrix entered can be the coefficients of a set of simultaneous equations, and entering a second matrix allows the system to be solved.

Use of MATRX

Simple 2x2 Matrix

| 2  -3 |
| -4  8 |

Run the MATRX program ( XEQ ALPHA MATRX ALPHA)

Options presented :

RL  CX

Press RL A

Option presented :

ORDER=?

2R/S

Options presented:

A  I  DT  B  SE

A

Enter the Matrix elements

2 R/S
3 CHS R/S
4 CHS R/S
8 R/S

Options presented :

A  I  DT  B  SE

If A is part of a system of equations, for example

2x - 3y = 6
-4x + 8y = -2

Then enter matrix B

| 6 |
|-2 |

B

6 R/S
2 CHS R/S

Solve the System of Equations with SE

SE

Result is now in B

B

1:1 = 10.5 R/S
2:1 = 5 R/S

This means if

2x - 3y = 6
-4x + 8y = -2

Then X = 10.5 and y = 5

Check

(2 * 10.5) - (3*5) = 6
-(4 * 10.5) + (8 * 5) = -2

CORRECT!

A now holds the LU-Decomposition version of the original A To restore the contents of A to normal simply INVERT A twice

I I

Check A

A

1:1 = 2.00
1:2 = -3.00
2:1 = -4.00
2:2 = 8.00

Find the Determinant of A

DT

DET = 4.00

That's pretty much all for MATRX with a real matrix.

Complex Matrix

You can chose CX at the beginning, and enter the Real and Imaginary parts of each Matrix element if you are dealing with a complex matrix.

— John Pumford-Green 05/08/22 11:55

Further Information

DM41X Polynomial Solver

anonymous@undisclosed.example.com (Anonymous) — Mon, 16 Feb 2026 08:51:52 +0000

←Hints & Tips

DM41X Polynomial Solver

Advantage Pac Polynomials

Assuming Advantage Pac is plugged in…

Finds all roots, including complex ones.

Save to registers

To save the discovered roots in registers

Enter the polynomial coefficients as normal
prior to pressing RT to do the solve SET FLAG 06
- ShiftSF06
This will save the discovered roots in R24 upwards
- saves in pairs as REAL and IMAGINARY
  - R24 = REAL root 1
  - R25 = IMAG root 1
  - R26 = REAL root 2
  - R27 = IMAG root 2
  - etc
  - etc

Roots of a quadratic

To find the roots of a simple quadratic (with 2 real roots)

x² - 3x + 2 = 0

XEQ ALPHAPLYALPHA
Asks for DEGREE=?
- this is the highest power of x in the polynomial
- enter 2 R/S
Asks for a2=?
- the coefficient of x²
- enter 1 R/S
Asks for a1=?
- the coefficient of x
- enter 3 CHS R/S
Asks for a0=?
- the constant term
- enter 2 R/S
Display shows FX RT NEW
- FX = Function value at your choice of x
- RT = Root(s) of the entered polynomial
- NEW = Enter a new polynomial
- Choose RT B
Display shows ROOT = 2.0000
- to see next root press R/S
Display shows ROOT = 1.0000

The roots of our quadratic are 2 and 1

Higher order with complex roots

Either press TAN (J) to get the menu, and then NEW (LN) or XEQ PLY again

4x⁴ - 8x³ - 13x² - 10x + 22 = 0

This should have 4 roots, and most likely some will be complex.

DEGREE=?
- 4 R/S
a4=?
- 4 R/S
a3=?
- 8CHSR/S
a2=?
- 13 CHSR/S
a1=?
- 10 CHSR/S
a0=?
- 22R/S
FX RT NEW
- RT B

Roots are displayed:

U = -1.0000 R/S
V = 1.0000 R/S
U = -1.0000 R/S
V = -1.0000 R/S
ROOT = 3.1180 R/S
ROOT = 0.8820 R/S
FX RT NEW

The 4 roots are

-1 + j 1
-1 - j 1
3.1180
0.8820

Cube Roots of minus 8

If x is the cube root of minus 8 then x³ = -8 and as a polynomial x³ + 8 = 0

Simply use 0 as the coefficient of X² and x

XEQ ALPHAPLYALPHA
Degree=? 3 R/S
a3=? 1 R/S
a2=? 0 R/S
a1=? 0 R/S
a0=? 8 R/S

RT B
- ROOT = -2.0000 R/S
- U = 1.0000 R/S V = 1.7321
- U = 1.0000 R/S V = -1.7321

Roots are
- 2.0000
- 1 + j 1.7321
- 1 - j 1.7321

— John Pumford-Green 26/01/26 09:55 GMT

Further Information

calculator, dm41x

Page updated : 10/02/26 17:40 GMT

DM41X PPC ROM Curve Fit

anonymous@undisclosed.example.com (Anonymous) — Tue, 17 Feb 2026 08:00:01 +0000

←Hints & Tips

DM41X PPC ROM Curve Fit

The PPC ROM's CV function does similar Curve Fitting to the Advantage Pac CFIT program, without the limitation on negative data point values.

Negative X values are acceptable for Linear and Exponential curves

Negative Y values are acceptable for Linear and Logarithmic

If any data point has BOTH X and Y negative then only Linear is possible.

Running CV

XEQ ALPHACVALPHA

Unlike CFIT there is no displayed menu for the top-row buttons, so you need to remember the functions.

Key	A	B	C	D	E
Shift	∑-				Initialize
	Σ+	Solve Type J	Y	X	Solve Best Type

Unlike normal Stats entry (where Y-value is entered first, then ENTER, then X-value is entered second, so that the X-value is in the X register before pressing ∑+) here we enter in “conventional” order.

Clear old data SHIFT E (Initialize)
X ENTER Y Σ+
X ENTER Y Σ+
X ENTER Y Σ+
X ENTER Y Σ+
etc…..

once the data is accumulated either

enter a fit-type digit (J)
- 1 : Linear : Y = b*X + a
- 2 : Exponential : Y = a*e^bX
- 3 : Logarithmic : Y = b*Ln(X) + a
- 4 : Power : Y = a*X^b
then press B to Solve Type J

press E to Solve Best Type

The solution appears as

Z : r correlation coefficient Y : a coefficient X : b coefficient

You can now get estimates of Y (for a given X) or X (for a given Y)

You can accumulate more data (to add to what's already there) and do another FIT calculation.

If you want equally spaced X coordinates for single variable Y-data CV puts incrementing digit in X so you simply

ENTER Y₁ Σ+

ENTER Y₂ Σ+

ENTER Y₃ Σ+

ENTER Y₄ Σ+

…

and you accumulate as if you'd entered (1,Y₁), (2,Y₂), (3,Y₃), (4,Y₄)…

If you have X and Y data then the automatically incrementing X is overwritten by the manually entered real X values.

Examples

Manual Linear Fit

Data

Negative X and Y values allowed for a Linear Fit

X	Y
-1.5	-3
1.1	5.2
4.5	12.6
8.0	20.0
10.0	23.0
15.6	34.0

Entry procedure

SHIFT E Initialize
1.5CHS ENTER 3CHS ∑+
1.1ENTER 5.2 ∑+
4.5ENTER 12.6 ∑+
8ENTER 20 ∑+
10ENTER 23 ∑+
15.6ENTER 34 ∑+

Fit to Linear

1 (for Linear Fit J = 1) B

Results

Z : 0.995734680 : r correlation coefficient
Y : 2.017167182 : a coefficient (y-intercept)
X : 2.113978698 : b coefficient (gradient)

Linear Equation : Y = 2.114 X + 2.017

Estimations

Predict Y for X = 20

20 C
- 44.9674114

Predict X for Y = 25

25 D
- 10.87183747

Best Fit Method

Further Information

calculator, dm41x

Page created : 16/02/26 20:13 GMT

Page updated : 17/02/26 08:00 GMT

Hints & Tips

anonymous@undisclosed.example.com (Anonymous) — Tue, 04 Mar 2025 07:27:15 +0000

←Calculators

Hints & Tips

Page Info

Page created Wed May 25 16:03:44 2022 by John Pumford-Green

Page last updated: 04/03/25 07:27 GMT

calculator

John's Vademecum - public:calculator:guides

DM41X 41z Module

DM41X 41z Module

Keyboard Overlay

Setup

Module

User Guide

ZK?YN (UPDATE 5/8/22)

Some commands still require the Z prefix to access sub-functions

Quick Ref

Basic Operation

enter two numbers and add them together

The ''natural'' entry method

Enter a real number

Enter an imaginary number

Use it to calculate with....

Parallel Impedances

convert to Rectangular ⇔ Polar operation

enter a number directly in Polar format

Cubic Roots

Rectangular

Polar

Alternate input method

gotcha

use ↑IM/AG instead

DM41X Advantage Pac

DM41X Advantage Pac

Useful Functions

The most useful to me are

Also available are

These are less useful to me (at the moment)

Flag 21

Further Information

DM15L Non-linear Curve Fit

DM15L Non-linear Curve Fit

Background

Tl;dr

Method for Exponential

Method for Logarithmic

Method for Power

Exponential

Mechanism

Example Data

Method for Exponential

Logarithmic

Mechanism

Example Data

Method for Logarithmic

Power

Mechanism

Example Data

Method for Power

Further Information

DM15L/41X/41L "Multi-Variable" Solve

DM15L/41X/41L "Multi-Variable" Solve

Source

Example : OHMS LAW

Example : Nano-VNA TDR settings

Example

Further Information

DM15L Startup Keys & Serial Console

DM15L Startup Keys & Serial Console

Start Keys

Serial Console

Settings

Commands

An example session

DM16L Startup Keys

DM16L Startup Keys

Start Keys

Further Information

DM41X Catalogues

DM41X Catalogues

What the different Catalogues show

DM41X Curve Fitting

DM41X Curve Fitting

Curve Fit values

Example of a Best Fit (LOG)

Further Information

DM41X Ladybug Module