HP 41 advantage module


Hi guys

Couple of months ago I bought my 1st 41-series model (41CV), the calculator I could not afford when it was in production. I am an RPN enthousiast and I am one of those guys who actually use their vintage calcs (even use a 67 sometimes). What I sometimes miss in the 41 series however (in contrast to my 34C, 15C, 32SII and 48G) is a build-in numerical integration routine. OK, you can write a program for it, but user-programs run more slowly than (hardware-implemented) build-in functions, at least that is my experience. However, I know there exists this so-called advantage-module which HP introduced to allow the 41-series to remain a top of the line calc even after the introduction of later models.
My questions are: do the advantage modules have integration (and solve) routines, and if so, how fast are these routines. Finally, how easy/difficult is it to obtain an advantage module and how expensive are they.
Thank in advance



Jan --

Quick answer: Yes, the HP Advantage has machine-coded INTEG and SOLVE that are basically the same routines of the HP-15C/HP-34C. They run about twice as fast on the HP-41. Check my Article #556 in the HP Museum Articles Forum (this website) for background.

Expect to pay > US$40 on eBay. They are frequently offered. The scanned manual is available on CD/DVD from this website, if none is included in the eBay auction.

-- KS

Edited: 2 Oct 2006, 10:22 p.m.



" do the advantage modules have integration (and solve) routines"

    Yes and yes, plus full microcoded matrix functionality and assorted goodies.
", and if so, how fast are these routines."
    Microcode speed, i.e, 41C-assembly language implementations, i.e., as fast as they go.
"Finally, how easy/difficult is it to obtain an advantage module"
    Pretty easy.
"and how expensive are they."
    Mine were $70 and $80 at eBay. Including pretty good, comprehensive spiral-bound manual.
"Thank in advance"
    You're welcome. Have a look at my 8-page article in PDF format about the Advantage ROM ("Long Live the Advantage ROM"), including a 62-step demonstrative program using Advantage ROM fuctions, and full examples here.
Best regard from V.

Edited: 29 Sept 2006, 4:37 p.m.


I lucked out at got an Advantage Module along with the 41 that I got off of eBay. Actually, it came with both the Advantage and the Math/Stat. There seems to be some overlap - and the Math and/or Math/Stat modules seem to go for a lower price.

Does anyone know how these modules compare?

BTW, I've found downloading the V41 emulator and evaluating the ROMs on a PC/41 emulator before I decide which ones to buy great fun.




I have both the Math (not Math/Stat) and Advantage module and yes there are overlaps, such as the Runge-Kutta differential equation solver and the coordinate transformation and complex number routines.

Of interest to the OP is that the Numerical Integrators are not the same. The Math module implements the classic Simpson's Rule, whereas Advantage uses the more sophisticated Romberg method. The Matrix routines in each seem pretty different too.

On can always download a good HP41 emulator that emulates all of the modules with it and compare and contrast for oneself. I have P41CX on my Palm--not a perfect handheld emulation of the HP41, but the cheaper shareware version includes an emulation of most of the commonly emulated modules, including Math, Stat, and Advantage.



Kevin --

I have both; here's a comparison:

The Advantage Pac contains 12 kB of code, much of which is machine code, and the rest is RPN routines. The Math Pac is a 4 kB module containing only RPN routines.

The Advantage Pac contains the following RPN-program functionality copied or adapted from routines in the Math Pac:

  • Polynomial Solutions and Evaluations
  • Differential Equations
  • Operations with Complex Numbers
  • Coordinate Transformations

The Advantage Pac contains the following functionality that was implemented completely or primarily as machine-coded programs, while the Math Pac contains related but limited functionality as RPN routines:

  • Matrix Operations
  • Roots of an Equation
  • Numerical Integration

(See NOTE 1 below.)

The Math Pac contains the following functionality that is not present on the Advantage Pac:

  • Fourier Series
  • Hyperbolics (see NOTE 2 below)
  • Triangle Solutions

The Advantage Pac contains the following functionality that is not present in the Math Pac or any other official HP-41 module by Hewlett-Packard:

  • Vector Operations
  • Numerical (base integer) Conversions and Boolean Logic

The Advantage Pac contains the following functionality that was adapted from other HP-41 Pacs:

  • Curve Fitting (adapted from Stat Pac)
  • Time Value of Money (TVM) (adapted from Finance Pac)

NOTE 1: From the Acknowledgments section of the Advantage manual:

"The matrix operations in this pac were based on the CCD ROM, written by W & W Software Products GmbH [of Germany]..."

The root-finding and numerical-integration routines in theis pac were adapted from those in the HP-15C by Firmware Specialists [of Corvallis, Oregon]..."

NOTE 2: RPN code for hyperbolic functions (but not their inverses) in the Advantage Pac was copied from the Math Pac, but the function entry points (external labels) were not provided. More about that:



-- KS

Edited: 2 Oct 2006, 10:26 p.m.


I suggest you get a Clonix or MLDL2000 so you can play with all the modules in the world



Hi Meindert,

are there still MLDL2000 on sale? What are your conditions?

Best regards,


I am thinking about doing that, actually. Could you compare and contrast the Clonix to the MLDL2000. Also, how much do they cost?




Hi Kevin, guys;

I own two MLDL2000 and two NoV-series modules (1 NoVRAM and 1 NoV32). Although they are meant to be HP41 programmable/updatable ROM extensions, I think that a direct comparison does not actually reflect their relation with each other.

The MLDL2000 may store up to 127 different ROM images in FLASH ROM and has space enough to hold up to 63 blocks (SRAM) of up to 4KByte each. The user can program up to eight different configurations, ranging pages #0 to #F (full range). Based on the MLDL2000 specifications, it would be possible to run an HP41 without the ROM chips if you have a MLDL2000 configured to emulate such ROM images (system rom chips, pages # 0, 1 and 2). The MLDL2000 is housed in a regular HP82104A case (HP41 card reader).

Eech of the Clonix-series module allows six ROM images to be configured in any page ranging page #5 (or #6, I do not remember) to page #F. Clonix has 512bytes of user programmable nonvlatile RAM, NoVRAM has 16K (equivalent to one HEPAX memory module, or 4X4K pages) and the NoV32 has 32K (two times the NoVRAM user memory). Any Clonix-family module fits in a single port, it comes in a regular ROM-module case.

I do not know how much each of these marvelous achievements cost today. Anyway, every time I talk about them I must add: Thanks Meindert, Thanks Diego. Althought these are your achievements, we are the ones who actually feel gifted. Any HP41 user might be forever thanked to you both.

Best regards.

Luiz (Brazil)

Edited: 1 Oct 2006, 2:30 p.m.


All info about the MLDL2000 can be found at hp41.kuipers.to. There is currently still a waiting list, but I will probably be able to have a small batch manufactered to satisfy my waiting list. The problem was that several failed the production test and cannot be repaired anymore. I made a deal with the company that produced the MLDL2000 and can offer some new units at the same price.

For the CLonix modules go see www.clonix41.org


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