egl2020 6 minutes ago

I still have the wooden 10" Keuffel and Esser that I inherited from my father and that I used in college. These days I use my HP15C unless I want to provoke glee and amusement in my younger colleagues by sporting my Pickett slide rule in my shirt pocket.

watersb 11 minutes ago

A sort of non-logarithmic slide rule, the E6B Flight Computer, was still in use when I was a student pilot 20 years ago. I still carry one: they don't require electricity (although using one in the dark requires a light source).

https://en.wikipedia.org/wiki/E6B

JKCalhoun 2 hours ago

Deep dive, for sure. I suspect Cliff Stoll is enjoying this site.

I played with creating a logarithmic slider thing [1] in Javascript that I hoped I could package up as a kind of "widget" people could use on their web pages. But I don't really know Javascript that well—or rather how to make an API out of a Javascript thing.

Anyway, to test it I tried to make an Ohm's Law calculator [2].

I would love to see a site like the one in this post have some kind of interactive slide rule on the web page itself.

[1] https://github.com/EngineersNeedArt/SlideRule

[2] https://www.engineersneedart.com/ohmslaw/index.html (the yellow slider is not directly user-moveable in this example)

jamesgill 42 minutes ago

Last week I donated several slide rules to Goodwill; a few were very nice. Meanwhile, I still have a pristine HP-41cx and HP-15c, and an HP-25 app on my iPhone.

  • incanus77 7 minutes ago

    I have an HP-15c as well as a 16c and I've been using the latter on a daily basis while writing a byte-level network protocol client. I'm getting faster by the day and on the verge of writing some programs for shortcuts on the calculator. I still use the excellent PCalc as well, but seem to be faster on the physical calculator, which is kind of surprising.

clickety_clack 2 hours ago

Slide rules are super cool. Such an easy gift to give the engineer in your life.

I never spent the time to get quick with it, but I could absolutely see it being quicker than a calculator. You’d just have to be aware of the limits to its precision if you were in a field that required it.

fjfaase an hour ago

I have one at home, which is the one we had to buy to use in highschool. In the math classrooms we had a 6 feet version that could be mounted on the blackboard such that the teacher could used for instruction. See for a picture on the Dutch page https://rekenlat.barneveld.com/rekenliniaal.htm

  • watersb 18 minutes ago

    These TMSLs were also reasonably common in classrooms in the United States in the 1950s.

    Two Meter Slide Rule

gerdesj an hour ago

It is worth keeping one around.

When the "cloud" is raining and your laptop and phone batteries are drained and you suddenly need to navigate your 4823 times table - its got you covered.

You will also need to work out how to write with a pen or pencil on paper or try and fix up your atrophied ability to remember arbitrary "facts" short term.

NetMageSCW 2 hours ago

The HP-35 wasn’t programmable- it was just a scientific calculator.

kingforaday 2 hours ago

This would have been helpful for Sam Cooke.