It wasn't programmed because it was never built (in his time anyway). I am assuming you are talking about the Analytical Engine, rather than the Difference Engi

It wasn't programmed because it was never built (in his time anyway). I am assuming you are talking about the Analytical Engine, rather than the Difference Engine, since the latter is not a Turing machine. The method of programming was to be via punched cards, whose contents was roughly analogous to machine code.