Here you will find a wealth of data I have collected over the years on general calculators, HPs calculators, TIs calculators, and on my all time favorite mechanical calculator, the CURTA.

I recent years I have become an expert with the amazing Curta calculator. And it's mechanical not electronic! But it represents a final ultimate, state-of-the-art achievement in the mechanical world before the electronic calculator revolution took over and over night obsoleted all mechanical machines. Interestingly the Curta held on for many years because it was so popular among road rallyest and surveyors.

I do collect and study the manufacturing variations of the two models of the Curta calculator. My two exploded view Curta posters are wildly popular around the world and have been featured in museum displays and displayed in the halls and offices of NASA.

My favorite electronic calculators are HPs but I don't plan on this page even starting to compete with "The Museum"! HP introduced the 1st scientific calculator (HP-35) then introduced the first business calculator (HP-80). To this day the all time most popular calculator is the HP-12 Business calculator. I still like to gripe about why HP abandoned the scientific calculator (HP-11, HP-15) in this wonderfully convenient format.

My Calculators of HP poster is another popular poster I created. It even serves as a reference in the support offices of HP.

Finally my newest posters of the History of the Telephone and Modern US Currency are the latest additions to my poster line up. Yes, a slight deviation from calculators but I always remembered touring the phone company as a child and receiving a poster that showed the history of the telephone. My Telephone poster is an updated tribute to this now 45 year old poster.

I also find the art and design that is in the US currency amazing. My Modern US Currency poster arranges all the major version of all the denominations. Showing both the front and back side of each bill so you can study and appreciate the art and changes that have happened to the US currency over the past 100 years or so. I also hope this poster can serve as a teaching aid for school teachers.

Look around, enjoy yourself, and marvel over how calculators (both steel and silicon) have changed our world.

-Rick Furr-

Morse Code Click Here
The Telephone Story Click Here
Modern US Currency Click Here
The Curta Poster Click Here	The HP Poster Click Here
The Curta German Poster Click Here

(Click Here)

HP CALCULATORS

Learn more about the HP-12C Platinum, HP-32C, and the HP-33CS on the HP Reference page.

	HELP!!! Frequently Asked Questions Here are places that will help you with your most frequently asked questions concerning repairs, spare parts, and manuals.
	Calculator Collectors, Data, Classifieds, Mail Distribution Lists, and Forums The title says it all, this is a collection of Collector Lists, Data Lists, Classified Lists, Mail Distribution Lists, and Forums.  If you are wanting to buy or sell a calculator then reference the Classified Lists, Mail Distribution Lists, and Forums section.
	Free 42 (HP-42S for your PC) Free42 is a re-implementation of the HP-42S Scientific Programmable Calculator and HP-82240 Printer. It is a complete rewrite, not using any HP code. It does not require an HP-42S ROM image. Even though it contains significant enhancements compared to the original calculator, Free42 remains fully compatible with the HP-42S, both in its user interface and in its ability to run programs written for the HP-42S. Free42 is an Open Source project. The executables and source code are released under the terms of the GNU General Public License, version 2.
	Calc 98 Over a million PC users have already downloaded Calc98, our popular free engineering, scientific and financial calculator for Windows. The calculator includes functions for statistics, use of different number bases (binary, octal, hexadecimal and base-n), metric units conversions and physical properties and constants. It has financial functions including investment, loan and mortgage calculations. It also calculates time functions and has a stopwatch feature and RPN (Reverse Polish Notation). It runs on Microsoft Windows (WindowsNT, Windows95/98/ME, Windows2000/XP) and WindowsCE (Pocket PC).
	Desktop Calculators Here is some information on some very interesting and some very common desktops that I own.
	Keyboard Trivia Why is the telephone touch-tone key pad arranged differently from the calculator key pad? Why is the keypad arrangement different for a telephone and a calculator? Doing the Numbers - Why Calculator and Phone Number Layouts Differ
	Electronic Displays This is my article on Electronic Displays that appeared in the Winter-Spring 1997 International Calculator Collector.
	The Calculating Machines Numbers If you've ever been to Erez Kaplan's -- Calculating Machines page (now available at the Wayback Machine--thanks Angelica Landicho) then you will have noticed his cool rolling numbers image. Click this title if you would like to see all of the different numbers used in this cool image. Go to his page if you want to see the real thing.
	The Collector's Guide to Pocket Calculators "This is another must have for ANY calculator collector." - Rick Furr. "The Collector's Guide to Pocket Calculators" by Guy Ball and Bruce Flamm is back from the printer and now being shipped. This 200+ page, softcover book contains a detailed listing of over 1500 known portable/pocket calculators from the early 1970's (the "Golden Age of Pocket Calculators"), as well as historical information from the 1960's and 1970's. The book features over 470 photographs of various models from over 220 manufacturers around the world (including calculators from lesser-known companies in England, Switzerland, Netherlands, Spain, Germany, Bulgaria, and Russia). "The Collector's Guide to Pocket Calculators" also includes a comprehensive value guide to help you gauge rarity and desirability of the various models -- especially as they relate to each other. The book can be purchased for $23.95 plus $4 for USA first class mailing ($6 to Canada and Mexico, $8 for airmail to other countries). California residents please add $1.86 state sales tax. Mail to: Wilson/Barnett Publishing P.O. Box 345 Tustin, CA 92781-0345 USA For additional information, contact Guy Ball

Other Links

CURTA

• The CURTA Reference by Rick Furr
  
  
  
• See the Curta Page for more links

CALCULATORS

• Christophe Mery's Calculating Machine Documents
  
  
  
• Calculators' Pages by Walter Szrek
  
  
  
• Calculator History and Technology Archive Page by Alex Knight
  
  
  
• Calculator Technical Information by Mike Sebastian
  
  
  
• HISTORY OF THE CALCULATOR - by Josep Balsach
  
  
  
• Museum of Pocket Calculating Devices by Gerhard Wenzel
  
  
  
• Old HP and TI Calculators by Gene Wright
  
  
  
• Programmable Calculators by Viktor T. Toth
  
  
  
• The Old Calculator Web Meseum by Rick Bensene
  
  
  
• Vintage Calculators Web Page by Nigel Tout
  
  
  

Mechanical Info

• Calculating Machines - Illustrated by Herbert & Walter
  
  
  
• Mechanische Rechenhilfsmittel (Mechanical Calculating Equipment) by Wolf-G. Blümich
  
  
  

HP

• The HP Reference by Rick Furr
  
  
  
• The Calculator Store (Barcelona, Spain) by Jose Gonzalez
  
  
  
• HP calculators in Brazil by William
  
  
  
• Bring Back the HP-15C by Chris W
  
  
  
• HP-41 PROGRAMMABLE CALCULATOR by Warren Furlow
  
  
  
• HPPC - HANDHELD AND PORTABLE COMPUTER CLUB by HPPC (formerly PPC (UK))
  
  
  
• Making New Battery Packs for the HP-35 Calculator by Douglas W. Jones
  
  
  
• The Museum of HP Calculators by Dave Hicks
  
  
  

TI

• The TI Reference by Rick Furr
  
  
  
• DATAMATH CALCULATOR MUSEUM by Joerg Woerner
  
  
  
• TI 84 Online Calculator by Marcus
  
  
  

SLIDE RULES

• The Moonstick by Sean Barton
  
  
  
• The Oughtred Society by Jon J Cverna
  
  
  
• The Slide Rule Universe by Walter
  
  
  

OTHER

• Pigly
  
  
  Pigly is a free math and finance guide offering over 100 interactive calculators to help teach students about math and money.
  We also created a featured guide about the history of calculators for kids which shows all the different ways we use calculators in our day to day lives.
• Had TO Know
  
  
  Had2Know.com delivers information and online calculators for a wide variety of applications – finance, science, home & garden, mathematics, health & fitness, games, and much more. Is there something you just had to know? We hope we have what you're looking for. Put our extensive collection of online calculators to use, or browse our expertly written articles and how-to guides.
  
  
• Everyday Financial Calculators
  
  
  
• Easy Unit Converter
  
  
  
• Table/Maker Five
  
  
  
• Calculators Edge Web Page - Lots of web based calculator solutions by Rick Modi
  
  
  
• A collection of really good online calculators for use in every day domestic and commercial use! by John S
  
  
  
• Since its founding in 2003, AAC has grown into one of the largest online electrical engineering communities. by Kent Dresser
  
  
  
• The Nixie Universe by Walter
  
  
  
• Electronic Artwork by Guy Marsden
  
  
  

RALLY

• Rally Racing News -- Rally Odometer/Clock Manuals by Bill Jonesi
  
  
  
• "PEPPERMILL" OPERATIONS (15 Place Curta)
  A Rallyists Guide for the Use and Operation of a Curta Calculator by Diane E. Houseal
  
  
  

For Sale

• Antique Scientific Instruments on the Internet -- The Gemmary by R.C. Blankenhorn & Vince Austin