Charles Babbage invented his analytical engine between 1833 and 1871. The first freely programmable calculator, considered the first digital computer, was called the Z1 and was created in 1936 by Konrad Zuse. It spurred computer development around the world.
The Atanasoff-Berry Computer, or ABC, was created in 1937. Unlike the Z1, the ABC relied on vacuum tubes, which would become standard until transistors took over. While these later devices differed in how they were constructed, the Boolean logic and programming pioneered on these early valve devices stayed the same, and much of the research done on early computers still forms the basis for modern computer science.