Pinwheel mechanical calculator Pinwheel is a program which simulates an old fashioned mechanical calculator. Below you see a half size image: This type of calculators was invented around 1850 and they were in use until about 1970. Electronic calculators allready existed at that time, but they were very expensive. The mechanical calulator is build around a rotating drum with pins that can shift in or out. As the drum turns, an outward pin advances a gearwheel one step. A gearwheel position shows a digit. Pinwheel calculators may be found at antique shops, but they are becoming expensive and in most cases they are defective. If you search the web with phrases like "mechanical", "calculator", "pinwheel" you will discover private collections or musea showing beautifull machines. Using a Pinwheel calculator you can add, subtract, multiply or divide numbers with or without decimal points. My simulator features: control by mouse or keyboard In-Line help information and examples optional "step by step" operation, showing carry or borrow propagation Pinwheel is written for Windows. Programming language is Delphi-7. There is no installation procedure. Download pinwheel by clicking the download icon (lightning) at the top of this page. Just copy Pinwheel to a map of choice.