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 [timeline of computing](https://www.computerhistory.org/timeline/computers/)
 
 
+### The Complex Number Calculator (CNC) (1940)
+
+The Complex Number Calculator (CNC) was a mechanical device invented by George R. Stibitz in 1940. It used electrical relays to perform complex arithmetic operations on binary-encoded complex numbers, allowing for faster and more accurate calculations than by hand or with analog computers. 
+
+
+The machine had two input registers, one for the real part of a complex number and another for the imaginary part. The output of the calculation was displayed on a series of light bulbs. The CNC was groundbreaking in its ability to perform complex arithmetic in real-time using a mechanical device and paved the way for the development of electronic digital computers. 
 
 ### Model K Adder (1937)