Excalibur for Windows
Version:           2.05 released April 26, 2026
Requires:          Windows 9x, NT, ME, 2K, XP, Win7, Win8, Win10, Win11 (and probably later)

Welcome to Excalibur for Windows! Excalibur is a full featured RPN calculator for Windows 32-bit operating systems. 
It was designed exclusively as a Reverse-Polish-Notation (RPN) calculating machine and is crafted for both the 
beginner and the advanced user. Many users will enjoy the ease of use given the basic functions. For those more 
advanced needs, Excalibur has enough computational power to satisfy even the most experienced RPN aficionado.
Logical banks of functions cover everything from scientific calculations to business formulas to computer science
logic. The calculator also provides a robust programming mode which allows you to save time by automating number
entry, formulas and computational algorithms. But don’t let the vast features of Excalibur cause you to worry.
Beginners will also feel at home with Excalibur. Those new to RPN notation, please see the description on how 
to use the RPN notation with this calculator in the RPN Quick Start Guide so you can get up to speed on using
this computational tool.

Using the RPN notation greatly facilitated the programming effort. However, this was not the reason RPN was chosen.
I fully believe that RPN is superior to the more common algebraic notation for long or complex equations. I also 
feel that, given some practice to undo the old method, this method is more natural and more similar to how you 
would work out an equation given just a pencil and paper. I hope that using RPN has not turned any potential users
from trying this tool and I think the small effort in learning RPN may be worth the investment. Learning RPN does
not mean that you will forget how to use other calculators which use the standard algebraic notation but will 
give you the ability to use either variety with ease.

Excalibur was written over the course of 1994 to 2010. It grew from an antiquated DOS program I wrote called 
FCALC (1992) which, at the time, was switchable from RPN to algebraic. Although incomplete, this was a tool 
I used daily as I did not have the cash outlay for a good quality RPN calculator. In early 1994 work was started
on Excalibur for Windows 3.1. Most of the code was abandoned and rewritten for this new effort. For several years, 
it grew steadily but it was not released to the public. In 1995 I switched to Windows 95 and the Microsoft Visual C
compiler. For the next couple of years, Excalibur was enhanced and improved until I was ready to release it officially 
in the summer of 1997. Excalibur has become more than a hobby project. I receive a steady stream of email regarding 
the calculator. I’m always pleased to hear how this tool is being used out in the real world. The amount of effort 
taken to create Excalibur has been astonishing. I estimate that Excalibur has taken close to 800 hours to develop. 
My patient wife will attest that this is probably a conservative estimate! Although I require nothing in terms of 
compensation for use of this calculating tool, I’m still open to donations. If you want to learn how you can 
donate to support the effort, please see the Donations page.

Because Excalibur was written using mostly standard ANSI C with Win32 API calls (for the Windows functions), the main 
program EXCAL32.EXE is reasonably small (about 450Kb) and is completely standalone. It does not require additional DLLs 
or other files to run (well except EXCAL32.CHM which is the help file but even that is not technically needed). You can
simply place the small EXCAL32.EXE file onto a floppy and move it to any other computer with no hassle. The reason the
distribution file for Excalibur is larger (about 1MB) is simply because of the installation program (which many users 
prefer rather than installing Excalibur manually). In any event, once Excalibur is installed the single EXCAL32.EXE 
is all that is required.

Use the Table of Contents pane or the Index to navigate this help file. And be sure to read the disclaimer.

If you find a bug in this program or just want to let me know you enjoyed using Excalibur, please email me at daveber@gmail.com 
If you contact me, please include your Excalibur version number and your operating system (Win98, Win2000, XP, Win10, etc).

I would like to take this opportunity to thank everyone who took the time to download and try this program in its previous version.
The many emails and excellent feedback I got gave me the inspiration to continue developing this tool. Always feel free to let me
know what you liked and didn't like about Excalibur so that I can keep it as up-to-date and useful as possible. I especially want
to thank my Beta testers who took pre-release versions of this program and put it through its paces.

Enjoy Excalibur!
