Mechanical calulating machines that were the true acestors of todays computers were invented by?

Answer 1

The first calculating machine that included the concepts of a modern computer (data storage, programming, I/O) was the Difference Engine, conceived by Charles Babbage in the mid-19th century. It was never fully constructed because the Metallurgy of the time did not permit exact enough casting and machining for it to work accurately. A 20th-century effort to reproduce Babbage's work using modern metalworking techniques showed that his Engine was in fact practical. Many companies developed and sold functional mechanical calculators in the 19th century. However they did nothing but add, subtract, multiply and divide, and could not store data or programs. As technology developed in the mid-20th century these firms moved into computers, but their calculators were not truly "ancestors" in the sense that their functions did not evolve into computers. Instead these firms stopped building mechanical calculators and began building computers as a separate line of business.