[HN Gopher] Personal calculator has key to solve any equation f(...
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Personal calculator has key to solve any equation f(x)=0 (1979)
[pdf]
Author : todsacerdoti
Score : 50 points
Date : 2022-01-17 06:55 UTC (1 days ago)
(HTM) web link (people.eecs.berkeley.edu)
(TXT) w3m dump (people.eecs.berkeley.edu)
| mauricioc wrote:
| There's a very long interview with Kahan on ACM's YouTube
| channel. Here's a link to the part where he talks about the
| "Solve" button: https://youtu.be/smrs6FfnCzs?t=8670
| mikecarlton wrote:
| Check out the author. For those not in the know, Kahan was the
| driving architect behind IEEE 754 -- pretty much the basis of all
| computer floating point now. See
| https://en.wikipedia.org/wiki/William_Kahan
|
| I remember seminars at Berkeley where equipment manufactures show
| up to talk about their gear and Kahan would sit in the front row
| and grill them over their floating point implementations.
| antman wrote:
| So that is where Kahan summation algorthm comes from!
|
| https://en.m.wikipedia.org/wiki/Kahan_summation_algorithm
| tagoregrtst wrote:
| When you watch Sussman and Steele give the MIT 6001 course the
| audience are seasoned HP calculator guys and gals
|
| These must be the team who were designing the HP-28S and user rpl
| - the beautiful love child of Forth and Lisp.
|
| And what a calculator they put out!
| whartung wrote:
| RPL is just magic. It's really fun to work with.
|
| It's hard to appreciate what you're holding in your hand when
| you have one of these machines. When I learned the 48s had both
| Kermit and a serial port, the clouds parted and the sun came
| out. Really extraordinary capability in a $99 calculator.
|
| Always liked the form factor of the 28s, just needed a way to
| get code on and off (besides the printer port) of them.
| tagoregrtst wrote:
| And a better battery port. Also, dont confuse A23 batteries
| for N.
|
| But ya, i always like the 28 more than the 48.
|
| Have you heard of RPL/2? A modern implementation of RPL meant
| for scientific computing? Its annoying to compile but its
| quite nice!
| bluenose69 wrote:
| I had one of these way back when, and loved it.
|
| This is a great article, and reading it might give younger folks
| an idea of why HP users from the 1900s loved their calculators so
| much. They were designed for people who needed to get things
| done. And it wasn't just the algorithms inside. The physical
| machines were terrific, too. The pivoting keys left no doubt as
| to whether you had entered a digit (or whether, as in
| competitors' machines, the keystroke had entered the digit twice
| by mistake). And then there's RPN. Oh, lovely RPN -- trusty
| friend to those who needed correct answers and needed them in a
| rush.
|
| Such elegance (of machines and writing) is rare nowadays.
|
| Thanks for posting this, which brought back good memories.
| madengr wrote:
| People from 2020 still love the too, ha ha. I have several 35s
| at work and just got a Swiss Micros DM42 from xmas. Then again,
| I'm 50 and used these all through EE school and my profession.
| I have four 32sii still sealed in clamshell package. Went out
| and bought a bunch years ago when they discontinued them.
|
| https://www.swissmicros.com/product/dm42
| buescher wrote:
| I didn't realize at the time how much I learned from my HP-15c
| manual, which had a similar treatment of its numerical
| algorithms. Thanks HP!
| jcrawfordor wrote:
| Some years ago I bought a printing desk calculator. The
| manufacturer apparently wanted to minimize their translation
| bill for the manual, so it almost completely avoided any
| textual explanation, instead illustrating how to use all of the
| functions by showing number lines with arrows and the
| corresponding calculator buttons. At first it was frustrating
| but after getting used to it I actually thought it was pretty
| neat, as it encouraged a more intuitive understanding of
| exactly what the calculator buttons did.
|
| Relatedly I learned a whole lot of algebra from reading a slide
| rule manual. I don't think I had a good intuitive understanding
| of logarithms until I saw them as pictures with arrows showing
| how they work on the slide rule. And then the manual was full
| of practical ways to reduce various common math problems to
| problems that are easy to solve with the slide rule, usually by
| figuring out how to express them as powers or logarithms.
| ahmedfromtunis wrote:
| I'm really interested in reading these manuals. Do you recall
| what were they for?
| jcrawfordor wrote:
| For the former I unfortunately cannot find a copy and I
| don't have the calculator any more... my hazy recollection
| is that it was a Panasonic printing desk calculator I
| bought at Staples but that could be wrong. Fwiw the newer
| desk calculators seem to all have pretty bad keypads so if
| you want a calculator that's really comfortable to use for
| fast totaling you might want to get a "vintage" one from
| when they were using mechanical key switches. Part of the
| reason I got rid of the one I had is because I was having
| issues with it not always registering keypresses when I
| thought it would have.
|
| As for the slide rule, I believe it was a Pickett booklet,
| likely one of the ones that have fortunately been archived
| here:
| https://www.sliderulemuseum.com/SR_Library_Pickett.htm
|
| The Asimov slide rule book is also very good and I have a
| copy. I believe I inherited it, along with several slide
| rules, from my grandfather who had been an EE at the NIST
| and also fastidiously kept a lot of things he had bought
| for grad school. One of the slide rules has "US Government
| Property" silkscreened on with the scales which is fairly
| neat, I assume DoD or someone had had a large number made
| on contract like they used to do with office supplies. I
| also have a US Government Property set of drafting tools
| that I use when hand-drafting sewing patterns.
| pjmorris wrote:
| I had a similar experience with slide rule books I checked
| out from the public library in the 1970s. Looking on Amazon
| now, I see 'An Easy Introduction to the Slide Rule' by none
| other than Issac Asimov. It's entirely possible that this
| is the book I used, and I think it might fit your bill.
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