Mechanical computer

A mechanical computer is a <a href="/facts/Computer/SQe1aK05">computer</a> built from <a href="/facts/Machine/wTCxFRfs">mechanical</a> components such as <a href="/facts/Lever/HYDtMuAq">levers</a> and <a href="/facts/Gears/9KVHRfUR">gears</a> rather than <a href="/facts/Electronics/E4JhgISq">electronic</a> components. The most common examples are <a href="/facts/Adding_machine/oyHBLrrs">adding machines</a> and <a href="/facts/Mechanical_counter/yo7Rrx0Y">mechanical counters</a>, which use the turning of gears to increment output displays. More complex examples could carry out multiplication and division—Friden used a moving head which paused at each column—and even <a href="/facts/Differential_analyser/lgA1m3VS">differential analysis</a>. One model, the Ascota 170 accounting machine sold in the 1960s, calculated <a href="/facts/Square_root/AfrzfBdQ">square roots</a>.
Mechanical computers can be either <a href="/facts/Analog_computer/3NhYoCML">analog</a>, using <a href="/facts/Continuous_or_discrete_variable/TWl5feEw">continuous</a> or smooth mechanisms such as curved plates or <a href="/facts/Slide_rule/KzIEdWad">slide rules</a> for computations; or discrete, which use mechanisms like <a href="/facts/Pinwheel_calculator/8tL2J6Be">pinwheels</a> and gears.[clarify] 
Mechanical <a href="/facts/Computer/SQe1aK05">computers</a> reached their zenith during World War II, when they formed the basis of complex <a href="/facts/Bombsight/g2YSykBq">bombsights</a> including the <a href="/facts/Norden_bombsight/95QcXImB">Norden</a>, as well as the similar devices for ship computations such as the US <a href="/facts/Torpedo_Data_Computer/du3lLhsf">Torpedo Data Computer</a> or British <a href="/facts/Admiralty_Fire_Control_Table/F4FGDvK1">Admiralty Fire Control Table</a>. Noteworthy are mechanical flight instruments for early spacecraft, which provided their computed output not in the form of digits, but through the displacements of indicator surfaces. From <a href="/facts/Yuri_Gagarin/ucwoarjc">Yuri Gagarin</a>'s first <a href="/facts/Spaceflight/zPrnATzo">spaceflight</a> in 1961 until 2002, every crewed Soviet and Russian spacecraft <a href="/facts/Vostok_spacecraft/B25aaVjV">Vostok</a>, <a href="/facts/Voskhod_spacecraft/y3jTV72e">Voskhod</a> and <a href="/facts/Soyuz_spacecraft/meooRg7U">Soyuz</a> was equipped with a <a href="/facts/Voskhod_Spacecraft_%2522Globus%2522_IMP_navigation_instrument/To28TvqV">Globus instrument</a> showing the apparent movement of the Earth under the spacecraft through the displacement of a miniature <a href="/facts/Terrestrial_globe/8Pqs2IuQ">terrestrial globe</a>, plus <a href="/facts/Latitude/IBYqkjhU">latitude</a> and <a href="/facts/Longitude/HsC61ML9">longitude</a> indicators.
Mechanical computers continued to be used into the 1960s, but 
had steadily been losing ground to <a href="/facts/Digital_computer/SQe1aK05">digital computers</a> since their advent. By the mid-1960s dedicated <a href="/facts/Electronic_calculator/eeLfRS8L">electronic calculators</a> with <a href="/facts/Cathode-ray_tube/8NVGx5C7">cathode-ray tube</a> output emerged. The next step in the evolution occurred in the 1970s, with the introduction of inexpensive handheld electronic calculators. The use of mechanical computers declined in the 1970s and was rare by the 1980s.
In 2016, NASA announced that its <a href="/facts/Automaton_Rover_for_Extreme_Environments/DkASRook">Automaton Rover for Extreme Environments</a> program would use a mechanical computer to operate in the harsh environmental conditions found on <a href="/facts/Venus_(planet)/pADnueP6">Venus</a>.

Mechanical computer open-in-new

Mechanical computer