We also had a black and heavy Remington Rand electromechanical printing calculator which also had a name: "La Máquina Negra." I loved listening to the cranking sound of its vertical bars crunching numbers while a division was performed. Yes, it was noise, but noise was a natural part of the shop’s environment.

Years later, during the 70’s at school, I became familiar with slide-rules and, of course, I was lucky to witness the appearance of the first pocket calculators. "La Chocolatera" and "La Máquina Negra" were still in use when my father closed the factory by the middle 80’s.

I knew about Burroughs machines and even saw a Comptometer or two in my life. I thought I had first hand experience with non-electronic calculating devices; so, when I decided to write an article on the history of mechanical calculators some weeks ago, I was not expecting the unexpected. Of course I didn’t know about Schickard but, although I was not aware of their involvement with the calculating machines, Pascal and Leibniz were very familiar to me. I like math, history and technology, so it was a pleasure to read about the Pascaline, the Arithmometer, the Curta, and so on… But then, suddenly, the unexpected occurred! Lots of little devices of whose very existence I was not aware started to appear all over the sites I was researching on the Internet. I am talking about the slide adders and "Troncets." The more I learned about them, the more I knew this was a completely new kind of device for me.

I must confess at this point that initially I had a hard time trying to understand how they worked internally. The materials I saw described how to use them, but no details were given about its internals. I want to take this opportunity to thank Eusebio Huélamo, a collector from Spain, for his patience in trying to describe with words how they work internally, and Robert Otnes for his helpful information. I’m still waiting for the pleasure to have one of those devices in my hands and make it work. I know the time will come.

I also want to take this opportunity to express my gratitude to Skip Godfrey, Eusebio Huélamo, Daniel Lewin, Andries de Man and my daughter Marisol, for the review and valuable suggestions they made to my initial drafts, and to Guy Ball for his help in gathering information for this site.

A web site about the history of calculators cannot be complete without a fairly large amount of pictures used to illustrate the most important milestones. David Hicks, Erez Kaplan, David Weil, Harold Layer, Theo Lumens, Ingo Heeskens, Hub Kockelkorn, Bob Roswell, Guy Ball, Andries de Man, Gerold Becker, Guy Renard, Tim Bergin and Seth Gordon, were very kind in letting me use the wonderful pictures exhibited on their web sites.

I also want to say thank you to Nicholas Bodley, Bruce Flamm, Ernie Jorgenson, Enrico Tedeshi, Jay Respler, Yves Serra, Michel Bardel, Tim Bergin, Andreas Lanz, Steven Feiner, Miha Podlogar, Ralph Beckman, Shawn Kelsey, Gerno Kaufmann, Timo Leipala, Louis Skelton, Richard Rose, Frank Rauck, and Kevin Corbitt for their contributions, information and materials they sent me in response to my request for information.

Through Erez Kaplan’s and Kevan Heydon's mailing lists I have discovered there are many friends who share this interest in calculators. This area of my web site is dedicated to all of them.

James Redin.

December, 1997