All the ideal from people creative inventions in the pasted.
I would say mathematician calculations machines was the brain behind the development of the early computers.
The word "computer" was used in the 1600's which means Humans that could perform calculations and computations.
The computer in the 1800's weren't the same "computer" we have today. It was more of a machine base.
In the 1940's was when the first Digital Computer was built, called ENIAC from J. Presper Eckert and John Mauchly.
First computer was build in the 1930's, called ABC from Atanasoff-Berry Computer.
Charles Babbage actually made the First mathematician machine basic computer in the 1833-1871.