To add to this topic: the fast hardware adder, patented by IBM in 1957, now in some forms present in all fast CPUs, was already invented by Charles Babbage betw

To add to this topic: the fast hardware adder, patented by IBM in 1957, now in some forms present in all fast CPUs, was already invented by Charles Babbage between 1820 and 1830, before the middle of 19th (!) century as he designed his mechanical computing "difference" engine: https://en.wikipedia.org/wiki/Carry-lookahead_adder https://en.wikipedia.org/wiki/Carry-lookahead_adder Apparently, he was proud of that invention, only almost nobody was able to appreciate it then. From "Passages from the Life of a Philosopher (1864) by Charles Babbage" https://en.wikisource.org/wiki/Passages_from_the_Life_of_a_Philosopher/Chapter_V https://en.wikisource.org/wiki/Passages_from_the_Life_of_a_P... "The first idea was, naturally, to add each digit successively. This, however, would occupy much time if the numbers added together consisted of many places of figures. The next step was to add all the digits of the two numbers each to each at the same instant, but reserving a certain mechanical memorandum, wherever a carriage became due. These carriages were then to be executed successively. " A 3D model: https://www.youtube.com/watch?v=B2EDE8Srdcw https://www.youtube.com/watch?v=B2EDE8Srdcw by the author of: https://en.wikipedia.org/wiki/The_Thrilling_Adventures_of_Lovelace_and_Babbage https://en.wikipedia.org/wiki/The_Thrilling_Adventures_of_Lo...