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Sharp Models EL8 and EL-8M, portable, battery powered, 1971-72.Olivetti Divisumma 18, printing, portable, 1973.Olivetti Logos 58, printing, 3 chip MOS-LSI, 1973.Olivetti Logos 240, printing, 157 chip DTL-SSI, 1970.Friden/Singer/Hitachi Model EC-1115, 12 digit, 46 chip MOS-SSI/MSI, 1970.Facit Model 1135J, 16 digit, 7 chip MOS-LSI, 1971.
#Friden calculator patent series#
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Compucorp Model 155 "Surveyor", programmable, scientific, 1971-2.Casio Model AL-2000, programmable (core memory), 1970.Canon Model SE-600, 16 digit, TTL, programmable, 1971.Anita (Bell Punch) Model 1011-LSI, 1971.Of a selection of early electronic calculators. The following pages describe the internal construction and operation Rebuilding the Odhner 239 pinwheel calculatorĮarly electronic calculators - technical descriptions.Rebuilding the Odhner 127 pinwheel calculator.Rebuilding the Multo 113 pinwheel calculator.Rebuilding the Facit C1-13 pinwheel calculator.Rebuilding the Felt & Tarrant Comptometer.Notes on overhauling a mechanical calculator.Workshop, I would welcome your feedback via the You (and especially if they don't), or if you know of the originalįactory procedures, or of methods more suitable for an amateur The procedures that I use, and they work well for me. In rebuilding a significant number of machines of each type. The instructions are based entirely on my own experiences The complete disassembling and rebuilding of several common mechanicalĬalculators. The following pages provide detailed step-by-step instructions for Mechanical calculators - rebuilding instructions Original-Odhner pinwheel calculator, 1950s to 1970s.Multo Model 113 pinwheel calculator, manual, 1949-66.Monroe Model K full-keyboard rotary calculator, 1921."Millionaire" calculating machine, direct multiplying, 1895-1920s.Marchant "Figurematic" Model 10DRX fully automatic rotary calculator.Madas Model 20ATG fully automatic rotary calculator.Felt & Tarrant "Comptometer" key-driven calculator.Facit Model CA2-16 pinwheel calculator (fully-automatic).Facit Model C1-13 pinwheel calculator (hand-cranked).Often equally applicable (at least in principle) to other models from The descriptions are obviously based on a specific example, they are The internal mechanisms of a selection of mechanical calculators. The following pages provide illustrated technical descriptions of Mechanical calculators - mechanism descriptions Or technical enquiries from like-minded enthusiasts. I would be happy to receive corrections, further information, The expectation that my notes alone will get it back together! Please do not disassemble your machine in If you are planning to repair or rebuild a calculator, please read theĬalculator before commencing, especially the section on taking Responsibility for any consequences arising from their use by others. I do not guarantee that they are entirely accurate orĬomplete, or even applicable to any other machine. While I believe my descriptions to be substantially correct, Important part of our engineering heritage. Will assist others in the understanding and preservation of this These technical notes are presented in the hope that they Years old, and may reasonably be considered a part of the historical The calculators described here range from 30 to more than 100 On how keen I was to get to the bottom of things. The amount and type of detail varies, depending Software, and supplemented by published manuals, patent descriptions,Īnd third-party data. Observations, often involving reverse-engineering of both hardware and Understanding (and remembering) the technology and the operation of The notes were written originally for my own use, to assist me in Reference material that goes beyond the basic information on a Technical notes, mechanism descriptions, repair instructions, and This "Technical and Reference" section includes a variety of Early electronic calculators - technical descriptions.Mechanical calculators - rebuilding instructions.Mechanical calculators - mechanism descriptions.John Wolff's Web Museum - Calculator Technical Section John Wolff's Web Museum Calculator Technical and Reference Section