Version 5.1.00, Build 6608
© 2026 Torsten Manz
HP-15C Simulator
For Windows, Linux and macOS

# Introduction

This guide describes the features of the HP-15C Simulator. It provides the basic knowledge required to perform simple calculations with the Simulator. To take full advantage of all HP-15C functions, you should already be familiar with HP calculators using RPN or, even better, own a real HP-15C. This guide is not a manual for the real HP-15C pocket calculator.

In this guide, the term HP-15C is used to refer to both the Simulator and the real HP-15C when there is no difference between the two. Features that only apply to the real HP-15C or the Simulator are clearly marked.

## The Real HP-15C

In 1982, Hewlett-Packard introduced the HP-15C pocket calculator as the top scientific model of the Voyagers series. This series also included the 10C, 11C, 12C, and 16C models. One attribute that, in my opinion, distinguished and still distinguishes the Voyager series is its case format. Almost all pocket calculators before and after the Voyager series had a portrait format case. The Voyager series, on the other hand, came in a landscape format case. Not only did this case make them look incredibly expensive and professional, but it was also very handy. If you hold a Voyager series model with both hands, you can use your thumbs to press the keys. This, together with the RPN (Reverse Polish Notation) input logic, allows very fast and easy operation.

The design, the colour of the case, the gold and blue labels for the secondary functions, the haptics; this altogether made it a real Hewlett-Packard device.

More information about the HP-15C, the Voyager series, and HP pocket calculators in general can be found on the Internet (see the Links page).

## The Simulator

### What It Is

The Simulator mimics the behaviour of the real HP-15C. It does not emulate any hardware, such as CPU, ROM or memory, of the real HP-15C. That is why it is a simulator and not an emulator.

The Simulator is intended to be a useful RPN calculator for your PC desktop. It therefore takes advantage of the features of the underlying operating system and its GUI: programs can be saved to files so that you only have to key them in once. Pop-up menus provide quick and easy access to many of functions and features of the HP-15C. However, no new features have been added that are not supported by the real HP-15C.

The Simulator supports almost all functions and features of the real HP-15C. The Differences between the real HP-15C and the Simulator are rather small.

### History

Back in 1984, during my studies, I was looking for a professional pocket calculator. At first I thought about buying a TI-59 because it had magnetic cards, but it was no longer sold. The best money could buy at the time was the HP-41C series, but I found it too expensive. Then I discovered the Voyager series, with the HP-15C as the top model. It looked incredibly professional, so I bought one (Serial-No. 2442A03334).

Eleven years later, in 1995, I bought a PC on which I installed Linux and soon discovered Tcl/Tk. I played around a bit and wrote some really small applications. It was a lot of fun, but I was missing a real "challenge". In other words: I wanted to work on a serious project.

I cannot remember the exact date, but it must have been around 1996/1997 when I started designing the HP-15C interface with Tcl/Tk. The basic functions were quickly added and I was able to do simple calculations. Over the next two years I added more and more features and functionality. I had started simple and so was the code. At some point in the development I realised that I had to do a complete redesign. Otherwise it would not have been possible to implement all the functions of the real HP-15C (e.g. programming). I rewrote all the code, but had no time to test it. For about two years I did not work on the simulator at all.

In 2001, I was involved in a project using TkGnats as a frontend to Gnats. Someone complained that the scrollbars were all on the left side of the list boxes. As I was "fixing" this, I remembered that I once had my own Tcl/Tk project and restarted the simulator project. Over the next few months I tested it out, doubled the lines of code and, in June 2002, I showed it to someone for the first time. Then I started writing the documentation, fixing bugs and adding missing functions. Here now is the result of all this.

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## HP-15C Limited Edition

On the 1st of September 2011, Hewlett-Packard announced that they would be re-releasing the HP 15C scientific calculator as a Limited Edition. What they call "popular demand" was the wish, or should I say the dream, of thousands of fans of the HP-15C who signed a petition. I signed the petition and I of course bought one: Limited Edition Number 17697.

The HP-15C Limited Edition Owner's Handbook is available as a PDF file from the HP Inc. web site. It is an almost exact reprint of the original HP-15C Owner's Handbook. It can therefore also serve as a manual for the Simulator!

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## HP 15C Collector's Edition

In July 2023, the latest and final edition of the HP-15C, the "Collector's Edition", was released. It runs on the current HP-12C platform with updated firmware. This allows for up to 192 registers. A connection to a PC is possible via a POGO connector in the battery compartment and a suitable USB cable. The connection can be used to update the firmware and exchange data with other devices.

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## Requirements

The Simulator is written in the Tcl/Tk scripting language. It should run on all operating systems supported by Tcl/Tk 8.6.6 or higher.

It has been tested on several UNIX/Linux flavours, Vista/7/8/10/11 and macOS (from Sierra up to Ventura). Windows 95/98/ME/NT4/2000/XP are no longer supported. 32 bit systems are also no longer supported.

The packages for a specific operating system each contain an executable program for that platform. No additional software is required to run the executable. The source code distribution contains the Tcl/Tk source code only and not binary extensions. Tcl/Tk version 8.6.6 or higher is required to run the simulator source file. See the links page for where to download Tcl/Tk.

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Usage ▶