A site of endless curiosity

The World of Calculator Emulation – things to see and try

with 3 comments

Did you know that you can buy a brand new HP-12C calculator for $58?  The HP-12C.  If you were around back in the 1980’s you might know about the HP-12C.  Yes, Virginia, the HP-12C – the great RPN financial calculator in 2010 is the same HP-12C of 1981.  Nearly 30 years and this calculator remains, essentially, unchanged.  How can this be?  What’s the magic?  (Note: click any of the images to enlarge)


So what’s the big deal?  I don’t know.  I didn’t have a HP-12C back in the 1980’s.  But, through the magic of modern emulation we can find out about the magical HP-12C.  I checked the internet and in fact, there are quite a few HP-12C emulators out there that you can get for free.

Amazingly, I found a Windows 7 Gadget and a stand-alone application that emulates a HP-12C.  This is what the gadget looks like on the desktop along with some other gadgets.

On the web site where you can get this emulated HP-12C (see links below) it says that this is a toy.  Well, is it?    I spent about 30 minutes playing with this emulated calculator trying various financial calculations related to TVM (Time Value of Money), IRR (Internal Rate of Return), cash flow calculations, loan  payments, and a few more financial calculations.  The real HP-12C is programmable.  I did some simple programming on this emulated HP-12C and that works as well.  Also note, this is a RPN (Reverse Polish Notation) calculator.  So, if you have never done some basic arithmetic using RPN, well, here is your chance.

You can get the HP-12C Gadget and the HP-12C manual at these links

For Win 7, Mac OS, Stand-alone and Win 7 Gadget –
And you will need the manual from HP –

The World of Calculator Emulation

Now I was on a roll.  What other calculators can I emulate?  What about a high-end calculator like the Texas Instruments TI-84 Plus Silver Edition Graphing Calculator?  Feast your  eyes.  Here it is running on my Windows 7 machine.

I gave this calculator quite a workout including programming this emulated calculator in TI-BASIC.  The real version of this calculator can also be programmed in Z80 assembler language.  The real calculator has a USB interface allowing you to exchange programs between the calculator and a personal computer.  The emulated TI-84 to the left does not seen capable of this data transfer.  If it was, I would have tried some Z80 assembler code which I was able to snag on the Internet.

Someone put quite a bit of effort into writing this emulator.  In fact, the TI-84 is only one of a number of TI calculators that the underlying emulator can emulate.

What is questionable is that, it would seem, the ROM that the emulator needs to work would be Texas Instruments IP (Intellectual Property).

When installing the this emulator you have the option of getting the ROM from a real TI calculator or “Create a ROM image using open source software”.

You really need to use your own judgement on this.

You can get eveything you need to play “hands-on” with the emulator here –

You can get the emulator here –
Here is the Texas Instruments TI-84 manual –

If you really want to geek-out on this, the emulator also has a built-in debugger that runs alongside the emulated calculator.  (Click to enlarge)


You can find a ton of emulators of all sorts here –
HP Simulators –
Vintage Calculators –


I really don’t know the market for the HP-12C financial calculator that is presently available in 2010.  It would seem that even the smallest business owner would be using Microsoft EXCEL for financial models.  It is unimaginable for anyone working in a Fortune 500 corporate environment to be sitting at a desk working out any kind of financial calculations or models using a calculator – Microsoft EXCEL is the defacto standard.

The basic financial capability of the TI-84 far exceeds that of the HP12-C.  Not only can the TI-84 do the same financial calculations (and more) compared to the HP-12C but it can also graphically display the results and transfer data to and from a personal computer.

As for the emulators – especially Wabbitemu, these are amazing pieces of work.

In about 1981 or so I was able to meet Richard Stallman.  I and a few others spent a day with him when he was visiting Chicago from MIT.  During that time we all listened to Stallman’s vision of a world filled with Free Software and why it should be so.  Stallman was one of the most idealistic, driven, and tenacious people I have ever met.  It is good to meet such people from time to time in one’s life.

Wabbitemu, which represents a considerable amount of work is Open Source, free to use, free to modify and free to redistribute.  The source code is freely available.

Wabbitemu is licensed under Richard Stallman’s Free Software Foundation GNU Public License.  I want to belive that all the free software that is available today is the realization of Stallman’s vision that I heard way back in 1981.

Below is the preamble to the GNU General Public License and Stallman’s concept of “freedom” – or sometimes referred as “copy-left” – a play against copyright.

So, when you play with the emulators mentioned in this posting or use software licensed under a Free Software License take a minute to think about the people behind the vision, technology, and effort.


The licenses for most software are designed to take away your freedom to share and change it. By contrast, the GNU General Public License is intended to guarantee your freedom to share and change free software–to make sure the software is free for all its users. This General Public License applies to most of the Free Software Foundation’s software and to any other program whose authors commit to using it. (Some other Free Software Foundation software is covered by the GNU Library General Public License instead.) You can apply it to your programs, too.

When we speak of free software, we are referring to freedom, not price. Our General Public Licenses are designed to make sure that you have the freedom to distribute copies of free software (and charge for this service if you wish), that you receive source code or can get it if you want it, that you can change the software or use pieces of it in new free programs; and that you know you can do these things.

To protect your rights, we need to make restrictions that forbid anyone to deny you these rights or to ask you to surrender the rights. These restrictions translate to certain responsibilities for you if you distribute copies of the software, or if you modify it.

For example, if you distribute copies of such a program, whether gratis or for a fee, you must give the recipients all the rights that you have. You must make sure that they, too, receive or can get the source code. And you must show them these terms so they know their rights.

We protect your rights with two steps: (1) copyright the software, and (2) offer you this license which gives you legal permission to copy, distribute and/or modify the software.

Also, for each author’s protection and ours, we want to make certain that everyone understands that there is no warranty for this free software. If the software is modified by someone else and passed on, we want its recipients to know that what they have is not the original, so that any problems introduced by others will not reflect on the original authors’ reputations.

Finally, any free program is threatened constantly by software patents. We wish to avoid the danger that redistributors of a free program will individually obtain patent licenses, in effect making the program proprietary. To prevent this, we have made it clear that any patent must be licensed for everyone’s free use or not licensed at all.

The precise terms and conditions for copying, distribution and modification follow…

Written by frrl

October 23, 2010 at 7:27 am

Posted in Uncategorized

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3 Responses

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  1. Good recollection! I bought one in the late sixties. The HP I used the more was a HP 12c bought in the eighties (which I misled a few days ago and that’s why I am looking for an emulator, and happen to have a loook on HP 35, thanks to your site).
    Used a HP 71 too, even for detailed business plans.
    Do you happen to know whether exists a HP12C emulator working with Windows 7 64bits, and easy to desinstall? Thanks VT

    val trentew

    September 18, 2015 at 2:55 pm

  2. How did you get the TI – 84 emulator to have no window surrounding it? It looks clean that way!


    June 16, 2015 at 6:44 pm

  3. The first HP hand-held calculator was the HP-35. You can still play with one here: . I bought one new in 1973 for $400. At the time, it was amazing for its size.

    Elwood Downey

    October 24, 2010 at 2:27 am

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