[PLUG-TALK] Curta mechanical calculator

[Keith Lofstrom]

On Fri, Dec 10, 2021 at 03:31:39PM -0800, Randy Bush wrote:
> > I guess my youthful age prevented me from knowing about this.  Looks
> > like a Mech E's dream.
> > 
> > <https://arstechnica.com/science/2021/12/the-remarkable-history-of-the-hand-cranked-curta-mechanical-calculator/>
> > 
> > YouTube video describing its operation.
> > <https://youtu.be/loI1Kwed8Pk>
> 
> i still have two, mine and my dad's.  same for K&E log log duplex

Sigh.  This Curta discussion has unleashed the irrational
desire I had in high school for a Curta; a couple of boys
(with prosperous parents) had them.   When the pandemic
subsides, perhaps Randy will let me fiddle with his. 
It was (and is) irrational to covet a Curta, though I am
glad that two are in good hands. 

Randy can tell us whether there is any practical reason 
or technique to use two Curtas simultaneously.  They seem
like a both-hands device.

I got my first cheap wooden slide rule around age 10.  By
high school, I had saved enough money for a plastic circular,
and by college a metal K&E circular, which I still have.  
That was when the first handheld scientific calculators 
began to appear; I couldn't afford an $800 HP-35, so I
designed and built my own calculators with surplus scrap.

The first was a hand-wired four function monster that I had
to plug into a wall socket.  I memorized the process to
compute 1% accurate sin/cos/exp functions with that.

The second was a sleeker scientific calculator in a welded
stainless steel case, about as big as a thick paperback
book.   A few more functions (like erf() ) than the modern
Sharp EL-501x calculators that I now purchase by the dozen
and leave in every room. 

I used the metal-box calculator for grad school at UC
Berkeley;  it is in a nice tool-leather belt case,
custom-made by a Telegraph Avenue street vendor. 

I should open it and clean out the leaky NiCd battery
gunk that has likely accumulated over the decades.

I'm writing this with vi in an xterm on a mate-gnome2
desktop on a store-bought T60 Lenovo thinkpad.  I don't
build computers and calculators from chips any more,
though I do mod and upgrade the commercial ones.  
I am a proud voider of warranties and EULAs.

Keith

-- 
Keith Lofstrom          keithl at keithl.com