Why did I do it

For two main reasons: Not willing to spend money on the real thing I decided to build my own.

Because I do not like to get tired or dirty I soon settled for a virtual one.

I already did a few things in VRML, so it was a logical choice to use it for the slide rule.
VRML 2.0 allows for basic animations, and for more complex things you can use JavaScript Nodes.

All you need is a PC, and a little time :-)

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