This isn't related to the 6502, but it might be a topic of interest on this forum --- both generally considered to be obsolete technology!


I would that thought PC boards would be too thin, but this might be an idea.
I had been thinking of making the slide-rule out of aluminum bars. I agree that the cursor is the most difficult part.

If anybody wants my software for generating slide-rule images, I can provide that. I generate two formats:

• gcode for a CNC milling machine --- the idea is to use a scribe to scratch off the dark anodized aluminum (black or dark blue anodization for contrast)
• .PDF for photo-lithography --- Don Lancaster suggested this

I'm dubious of a binary or hex slide-rule --- non-decimal floating-point is going to be confusing!

My software can do any length. There are limitations though. For a 10" or thereabouts, you have one level of precision. For a 6" pocket slide-rule, you have less precision. I support both. I also support round slide-rules, using the pocket slide-rule precision.

For a wall slide-rule, you could use either precision. This was done in paint stores in the past ---a wall slide-rule was used to calculate the ratios of paints, and this was done so the customer could see the calculation being made.
There have also been wall slide-rules built in the past that provided high precision (a huge slide-rule with tiny markings and a magnifying glass on the cursor to read the marks). This doesn't work very well because the slide-rule has to be 10 times larger to provide 1 extra digit of precision. My software doesn't support high precision --- it could be upgraded in the unlikely event that somebody wants this.

More useful (if the word "useful" can even be applied to a slide-rule) is to make the scale roll over at a specific point to make division by that number fast. Slide-rules normally have scales that roll over at pi, but other numbers can be used. For example, when traveling to a foreign country, make a custom slide-rule before you go that has the current currency exchange rate hard-coded. Also, this can be done with marks on the scales. I designed a slide-rule that could be used at the poker table to calculate pot-odds for Texas Hold'em --- be the uber-nerd who whips out a slide-rule at the poker table!

There are some great slide rules for Android. Including a copy of a russian one. They feel very much like the real thing, at least on my tablet. And then there's those with inifinite length.. something you can't do with a physical slide rule.