Tuesday, September 16, 2008

The iPhone HP 41C emulator (i41CX) - because sometimes madness must be honored

An obsessed madman has created a full emulation of a legendary scientific calculator ...

Advanced programmable and expandable RPN scientific calculator with virtual thermal printer/plotter suitable for a wide variety of scientific, engineering, mathematical, financial, and academic applications.

  • RPN logic with 4 element stack
  • Powerful rich set of numeric and mathematical functions
  • Time, calendar, alarm, and stopwatch functions
  • 12 character display with alphanumeric capability
  • User definable keyboard with support for overlays
  • Expandability: four module ports provide access to additional functions (e.g. matrix operations, programmer functions, equation solvers, etc.) beyond the standard built-in functions
  • Ability to download module files from the internet
  • Program features: automatic line numbering, labels, branching, subroutines, interactive alphanumeric input/output, loop operations, indirect addressing, flag operations, and synthetic operations...
Note the word "HP" does not appear anywhere on this page or on the screens. It's just an "scientific calculator". Nudge-nudge.

It cost me $8 to buy this. I might use the timer, and I might use the calculator every few weeks.

I bought it because sometimes glorious madness must be honored.

Update 12/23/09: There's a comprehensive (of course) FAQ on the AL Software site and a mini-manual. The original HP 41C manual is probably a bit hard to come buy, but, inevitably, another wonderfully insane geek has an online version and the i41CX manual points to PDF scans of the original manuals (252 pages!). Yes, and there's anHP41.org domain.

The only mystery remaining is who wrote this incredible application. The answer can be found on the HP-41 archive website emulation page. (Or you could just look at the author credits on the "mini manual").

I must add that I've recently scanned the "mini-manual" and "staggering" comes to mind. For example:
... Need to solve first- or second-order differential equations? Need to perform complex number operations and functions? Need to perform vector operations? Coordinate transformations? Number conversions and Boolean logic? Curve fitting? Solve time value of money problems? These are essentially the problems for which the HP-15C and HP-16C were developed. The Advantage Pac provides these capabilities to the HP-41CX. Thus, by loading the Advantage Pac and creating the appropriate key assignments, you can turn the i41CX+ into a virtual HP-15C or HP-16C!...
Oookaay. And let's not mention the GPS tools.


Jodohl said...

Gordon, thanks for leading me to the madman's cave. I will urge every person whon ever enjoyed the pleasure of owning and using the HP 41 masterpiece tool to support this insane project. My HP M-code programming days are long gone, but it sure will do me good making the odd average value calculation the good ol' RPN way :-) Support this man (assume somehow this is a He...) before HP decides to squeeze the lemon for a few more bucks (they've started with the HP 12/15/16!).

John Gordon said...

It's wonderful, isn't it? Sometimes madness is so extreme it becomes quite reasonable.

There's an FAQ from the author with a lot more detail on features:


I too assumed the developer was a guy -- but, yo know, there's no gender reference on the web site ...