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Version: 1.06
Author: David Bernazzani
Release: January 10, 2001
Download file size: 812 kB
OS: Windows all



Excalibur for Windows 32-bit version is a freeware full featured RPN-only calculator. This is a serious calculator for serious users. Excalibur takes up a small amount of resources for all it does so well.

Excalibur does not use more conventional "algebraic" notation like many low-end calculators on the market. Instead it uses the high-powered parenthesis-free RPN notation (Reverse Polish Notation). This notation was named in honor of a Polish mathematician and logician named Jan Lukasiewicz. Polish notation places the operators in an expression before the numbers. RPN places them after the numbers (which is why they call it Reverse Polish Notation)

RPN is really nothing more than the method of entry of numbers and operators into the calculator.

Precision Notes (Overflow and Underflow)

Excalibur for Windows uses an 8 byte IEEE floating point representation of all numbers. This means that there are approximately 15 significant digits.

Excalibur uses 8 byte IEEE floating point representation. Because of this Excalibur will NOT be as accurate as a hand-held calculator. This is because floating point decimal values using IEEE floating point representation generally do not have an exact binary representation. This is a side effect of how the CPU represents floating point data. For this reason, you may experience some loss of precision, and some floating point operations may produce unexpected results.

Tool Tips and Key Help

By default (you can turn it on and off in the Settings dialog box) each function key outside of the typical numbers and ordinary arithmetic operations has a tool tip associated with it. If you rest the mouse cursor over a button, the tool tip will show in a small window below the mouse cursor. The tool tip will tell you a the full name of the key (the key names are often abbreviated to save space). If you want more help on how to use a particular key, you can click the Help button then click any button to get a better description for that key. As a shortcut, you can right-click on any key for additional information (saves having to hit the Help key first).

Programming Basics

Recording programs is very easy. On the primary keypad you will see a button labeled REC and one labeled PLAY. The REC key puts the calculator into program record mode. A "Rec" indicator will appear in the status bar near the bottom to indicate this and the stack will change and will show normal X, Y but the Z, T will now show the current program line and function. It is important to note that when you are in Programming REC mode, the keystrokes are being recorded but also the stack is still "live" and you are actually performing the calculations you are entering. I feel this is superior to the more traditional method of only showing the user the key values as they are pressed but not actually taking action on them until the program is run. In this way, you can feel your way though the programming effort and end up with less bugs in your program sequence. Every calculator key pressed (clicked) is stored in sequence until "Rec" is hit again which will turn off the record feature. Pressing PLAY will then cause the key sequence recorded to playback in rapid succession. So, for example, you could hit REC, 9, * and REC which would effectively multiply the X value by 9 every time PLAY is hit. Several hundred Excalibur keys can be recorded in this way. Once recorded, it will stay with the calculator (even between sessions - its saved to disk) until a new REC takes place. If you want to save your program more permanently, simply use the "Program Manager" menu selection from the File menu.

Technical Information

Because Excalibur was written using mostly straight ANSI C with Win32 API calls (for the Windows functions), the main program EXCAL32.EXE is reasonably small (341 kB) and is completely standalone. It does not require additional DLLs or other files to run (well except EXCAL32.HLP 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 (812 kB) 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.

Download Excalibur 1.06 (812 kB)

UPDATE - June 22, 2006: Excalibur 2.00 is finally out!

This is the long awaited update to the venerable 1.06 that has been out for years. This new 2.00 version contains a host of new features and better Win 2K and XP support.

There is no longer an automated install for Excalibur 2.00. You simply extract it to any directory and run it from there. Excalibur 2.00 is not designed to install any components or modify the registry. It will write a small Excal32.dat file to save settings, etc. You can remove older versions of Excalibur (1.06, 1.05, etc) using the stanard Windows Add/Remove Programs (since those older versions used a standard Installer).

Download Excalibur 2.00 (188 kB)

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