Sun Hemmi 259D, HP-34C, Keuffel & Esser 4181-1, HP-41CX

Welcome!

I have a weakness for old technology. It's not that I don't understand the new technology (I'm a software architect for a leading developer of high-end mathematical software) but there's something I find charming and elegant about the devices used in simpler times.

Just before the turn of the century, my trusty HP-42S calculator began having troubles so I set out to find a replacement. I was surprised to find that HP no longer made an equivalent RPN calculator. A colleague responded to my plight by giving me his retired HP-19C and HP-41CX calculators, both of which were in need of minor repairs.

Shortly thereafter, I discovered that there was a healthy trade in used HP calculators dating back to their earliest models from 1972, and I casually started collecting them. After a while, I got interested in slide rules as well, and have built up a small collection of those.

On this site (one of several I maintain), I plan to showcase my collection and post articles of use or interest to fellow collectors and users of slide rules and calculators.

Articles

• Review: HP 35s Programmable Scientific Calculator
• A Matrix Multi-Tool for the HP 35s Programmable Calculator
• Curve Fitting for the HP 35s
• A Tale of Two Whiz Wheels: E6-B versus CR Wind Solutions
• Repairing an HP-41CX Calculator

My collection of slide rules and calculators is small by most standards, but I actually try to use them all, so there isn't much of a point having too many of them. As I write a page for each slide rule and calculator below, its entry in the list will become a link. If one that you're interested in isn't a link yet, please check back soon.

Slide Rules: Aero Products Research E6-B9 Aristo Darmstadt Nr. 867U Aristo Pocket Multilog Nr. 870 Aristo Multilog Nr. 970 Aristo 970 Simulator Concise No. 300 Faber-Castell 111/54A Faber-Castell 2/82 Faber-Castell 2/83N Faber-Castell 62/83N Hughes-Owens 1777 (Post 1460) Jeppesen CR-3 and CR-5 Keuffel & Esser 4181-1 Lawrence Engineering No. 10-B Pickett N600-ES Pickett N3-T Sun Hemmi No. 259D

Calculators and Computers: Hewlett-Packard 19C Hewlett-Packard 32E Hewlett-Packard 34C Hewlett-Packard 41CX Hewlett-Packard 42S Hewlett-Packard 67 Sharp PC-1211 Pocket Computer Not Quite Historical Yet: As well as these vintage calculators, I own an HP 35s, made by Hewlett-Packard to mark the 35th anniversary of the first scientific calculator. Here is my review of the HP 35s, and two programs I've written: Matrix Multi-Tool and Curve Fitting.

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Visit My Other Sites

Collecting slide rules and calculators isn't my only hobby. I'm also interested in electric powered model airplanes, full-scale aviation, building my own full-scale plane, and electronics, all of which I maintain web sites about:

• Electric R/C Model Aircraft
• General Aviation
• Volksplane Construction Log
• Electronic Projects and Reviews
• MotoCalc Software for Electric R/C
• Stefan's Blog
• Stefan's Home Page