The 20b / 30b has been repurposed into a scientific calculator - The 34s ! (5667 Views)
Valued Contributor
Posts: 58
Registered: ‎09-11-2002
Message 1 of 6 (5,667 Views)

The 20b / 30b has been repurposed into a scientific calculator - The 34s !

[ Edited ]

You can find out much more about this by going to these two places:


The HP Museum Forum:


HP Museum Forum


and the Sourceforce location for the new calculator binary and documentation:


Sourceforge for 34s


For more information, please go and read information posted at these two sites.


NOTE: I do not work for HP despite my screen name AND more importantly... this repurposed calculator rom is in NO WAY connected to HP. It requires reflashing your 20b or 30b and can possibly result in trouble getting your 20b or 30b back to its original state.


That said, many have already flashed their 20b or 30b into a remarkably capable calculator that is full of functionality and is very fast! The developers of the firmware have called their machine the WP 34s. WP are the initials of the first names of the two developers.


The WP 34S features over 100 general purpose registers, more than 100 user flags, 506 program steps, 4 programmable hotkeys for your favorite functions or routines, and a 31 byte alpha register for message generation.


In addition to the RAM provided, the WP34S allows you accessing flash memory for voltage-fail safe storage of user programs and data. Flash memory features four segments (regions, banks) of 1 kB each. Segment 0 is the backup region, holding the image of the entire program memory, registers and calculator state as soon as you completed a SAVE. Segments 1 ... 3 hold programs only. Alphanumeric labels (see below) in flash can be called via XEQ like in RAM. This allows creating program libraries in flash. Use CAT to see the labels defined already.
Flash memory is ideal for backups or other long-living data, but shall not be used for repeated transient storage like in programmed loops (since it will not survive more than approximately 10,000 flashes). Registers and standard user program memory, residing in RAM on the opposite, are designed for frequent data changes – but will not hold data with the batteries removed. So both kinds of memory have specific advantages and disadvantages you shall take into account for optimum benefit and long lasting joy with your WP 34S.


Here is a picture of a 20b that has been reflashed as a 34s AND that has an overlay with the new key functions included:


Here is information from the owner's manual for the 34s:


"Dear user, now you have got your own WP 34S. It uses the mechanics and hardware of the HP-20b Business Consultant or the new HP-30b Business Professional, so you get their unexcelled processor speed and with the HP-30b also the famous rotate- and-click keys giving the tactile feedback appreciated in vintage Hewlett-Packard cal- culators for decades. On the other hand, the firmware and the user interface of the WP34S are carefully new designed and written from scratch to give you a fast and compact scientific calculator like you have never had before.

Its function set is based on the one of the renowned HP-42S RPN Scientific, the most powerful programmable RPN calculator built so far. We expanded this set, incorporating the functionality of the famous programmer‘s calculator HP-16C, the fraction mode of the HP-32SII, probability distributions as featured by the HP-21S, and added many more useful functions for mathematics, statistics, physics, engineering, programming etc. like

+ Euler‘s Beta function, Fibonacci number calculation, Lambert‘s W (all of these in the real and complex domains), the error function, incomplete regularized Beta and Gamma, Riemann‘s Zeta, the most  ̳popular‘ orthogonal polynomials, testing for primality,
+ many statistical distributions and their inverses like Poisson, Binomial, Geome- tric as well as Cauchy-Lorentz, Exponential, Logistic, Weibull for reliability analysis, Lognormal and Gaussian with arbitrary means and standard deviations,
+ programmable sums and products, first and second derivatives,
+ extended date and time calculations based on a real time clock,
+ integer computing in arbitrary bases from binary to hexadecimal,
+ financial operations like mean rate of return and margin calculations,
+ 80 conversions, mainly between universal SI and old Imperial units,
+ nearly 50 fundamental physical constants as precise as known today by nation- al standards institutes like NIST or PTB,
+ complete Greek and extended Latin letter fonts covering many languages (upper and lower case in two font sizes each).

The WP 34S is the first RPN calculator overcoming the limits of a 4-level stack

– forget worries about stack overflow in calculations. It features a choice of two stack sizes expanded by a complex LASTx register: traditional 4 stack levels for HP compatibility, 8 levels for convenient calculations in complex domain, for more advanced real formulas, or for whatever application you have in your mind. The WP 34S features a full command set for navigation in either size.


Firmware-wise, we have carefully checked everything we could think of to our best knowledge, so our hope may be justified the WP 34S is bug-free. We cannot guarantee this, however, nor can we bear any liability for errors in calculations nor their possible consequences. Nevertheless, we promise we will improve the WP 34S whenever it turns out being necessary – so if you discover any strange result, please report it to us, and if it is revealed to be an internal error we will provide you with an update as soon as we have one ourselves."



I have been using a 20b reflashed as a 34s for about a month now and it is VERY nice indeed. Well worth checking out.

Esteemed Contributor
Posts: 422
Registered: ‎02-04-2010
Message 2 of 6 (5,594 Views)

Re: The 20b / 30b has been repurposed into a scientific calculator - The 34s !

[ Edited ]

All my 30b functions gone ..... and a 34s is born!


I have re-flashed my 30b (which I could get cheaper on the e-fleamarket than a 20b), and now I go on the voyage of discovery.  :smileyhappy:


Much thanks to Pauli, Walter and Marcus for all their wonderful efforts and to the hpmuseum forum members for their contributions.




EDIT: NOTE, I believe that the programming cables are no longer available. I am in the UK and will be happy to re-programme a 20b/30b. I can install the crystal too (required for some options, please read the manual on Sourceforge). Your only cost will be the return postage of the calculator. Feel free to send me a private message from this forum.

Valued Contributor
Posts: 58
Registered: ‎09-11-2002
Message 3 of 6 (5,545 Views)

Re: The 20b / 30b has been repurposed into a scientific calculator - The 34s !

This really is a fantastic machine. Anyone with a 20b / 30b who wants to play should try it.


If you want an incredibly capable scientific programmable machine, you should consider buying a 20b / 30b and giving this a try.


Other than having less memory than the 35s, this machine is more capable in a large number of areas.

Valued Contributor
Posts: 58
Registered: ‎09-11-2002
Message 4 of 6 (5,376 Views)

Re: The 20b / 30b has been repurposed into a scientific calculator - The 34s !

The HP 34s continues to evolve and improve.


In addition to the 506 merged program steps in the main programming area, there are now 8 banks of "flash" memory available where you can store programs/routines you have copied there and execute them as if it is main program memory. Since it is VERY easy to transfer programs from your PC (or Mac) to the 34s over the serial cable, this means you can have access to any and all software written for the machine very easily.


This is one fabulous machine and will be the talk of HHC 2011 held at the end of September.

Occasional Visitor
Posts: 3
Registered: ‎03-07-2008
Message 5 of 6 (5,296 Views)

Re: The 20b / 30b has been repurposed into a scientific calculator - The 34s !

Besides the choice of initials, was there a determining reason for the model number?  I owned... well, still do, though it isn't working anymore... a HP-34C, and I loved using it.  I was wondering if there was any kind of functional resemblance to it.  I noticed that there were some familiar-looking labels on the overlay, like L.R. (linear regression), a THIRD shift key (g), etc.  I hope to successfully flash my HP-30b.

Valued Contributor
Posts: 58
Registered: ‎09-11-2002
Message 6 of 6 (5,255 Views)

Re: The 20b / 30b has been repurposed into a scientific calculator - The 34s !

Yes, download the manual and read about it.

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