Cahill, Jakobe (2012) Mechanical calculators. Orange Apple, Delhi, India. ISBN 978-81-323-2996-1
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Abstract
A mechanical calculator was a device used to perform the basic operations of arithmetic. The last mechanical calculators were comparable in size to desktop computers and were rendered obsolete by the advent of the electronic calculator. Description of the illustrated calculator: This is a pinwheel rotary type, operated by the hand crank at the right. Tips of the setting levers extend through the slots in the brass cover; pinwheels are inside. The result dials are inside the carriage at the front, which can be shifted sidewise. The right array of dials shows sums and differences, as well as the dividend for division. The other set of dials shows the number of cycles at each carriage position. This displayed number serves as a check on multiplication, and shows the quotient from division. "Butterfly" knobs clear the dials to zeros when rotated. The mechanical calculator was invented in 1642 and the first commercially successful device was manufactured from 1851. Machines with columns of keys were introduced in 1887 while 10 key calculators and electric motors appeared in 1902. The use of electric motors allowed for the design of very powerful machines during the first half of the 20th century. In 1961, A full-keyboard machine like the comptometer, called the Anita, became the first mechanical calculator to receive an all electronic calculator engine, creating the link in between these two industries and marking the beginning of its decline. The Anita was the only full-keyboard electronic calculator of any commercial significance. The last mechanical calculators were built in the middle of the 1970s. The mechanical calculator was preceded by and competed against clerical aids such as abaci, Napier's bones and slide rules, and various books of mathematical tables. The true precursors to the mechanical calculator were machines made of toothed gears linked by carry mechanisms like odometers, astrolabes, clocks and pedometers. Stylus-operated adders with circular slots for the stylus, and side-by -side wheels, as made by Sterling Plastics (USA), had an ingenious anti-overshoot mechanism to ensure accurate carries.
| Item Type: | Book |
|---|---|
| Subjects: | Q Science > QA Mathematics > QA75 Electronic computers. Computer science |
| Divisions: | Electronic Books |
| Depositing User: | Practical Student 02 |
| Date Deposited: | 09 Mar 2022 08:57 |
| Last Modified: | 28 Jul 2022 01:05 |
| URI: | http://odlsystem2.utm.my/id/eprint/2915 |
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