This is the start of an occasional series of postings on cool stuff (I’ve bought) from Ebay …

HP41cx – The Citroen DS (DS is a French pun for Godess ;-) ) of Calculators

I think as long as I’ve been a gadget geek, I’ve wanted an HP41 of some description. My first experience of any calculator at all was in about 1975 or so when my father brought home some kind of TI calculator. Sadly it wasn’t working reliably, and I wasn’t smart enough to work out what was wrong.

The HP41 series of calculators was the keystone of a complete computer system, including the HPIL serial interface bus (similar to USB), various printers, backing store and other equipment. Every 41 has four module slots which allow additional memory and pre-programmed ‘pacs’ to be plugged in. Most surveyors are probably using HP48gx’s or laptops by now, but back in the day, the HP41 was a great tool for people who needed a tough, preprogrammed calculating asistant.

Here’s a pic of a HP41cv (This pic lives at the wonderful Museum of HP Calculators) :

My HP-41Ccx is physically the same, but has some additional features inside, including a timer and alarm facilities.

The display on the calculator was Hewlett-Packard’s first foray into using liquid crystal, and they did a great design job. The display is very very clear with good contrast and a very distinctive font.

The keyboard is fairly soft to the touch with a nice soft over-center action. There is no audible click, mechanical or otherwise, but there’s no doubt that a key was pressed.

Unlike other calculators of the time, a button is used to toggle the calculator on and off. This is great since the switches on many calculators from this era have most likely failed or getting ready to.

Aside from the on/off toggle, the other buttons on the top row provide the ‘user’ mode, ‘prgm’ mode and ‘alpha’ mode. These allow a customised keyboard, program editing and alphanumeric input respectively.

It is a little smaller in the hand than it appears in pictures. The main thing though, is the sheer quality and appeal of this great design.

This is really hard to believe, but this calculator was designed back in the late 1970′s. As a further testament, production only ended in 1990. It really does seem that great pieces of design never, ever go out of fashion.

I’ll post some more when I’ve worked out how to do some programming.

Date adopted: 06/14/2005
Condition: Mint, with HP zipper case, original manuals, keyboard overlays, stickers and HP promo materials.