Analog computers still exist but they are neither general-purpose nor easily programmable. Their big strength is solving differential equations, which they do b

Analog computers still exist but they are neither general-purpose nor easily programmable. Their big strength is solving differential equations, which they do better than digital computers in some cases. General-purpose reprogrammability is the key advance of modern computers. Although it can be argued that Babbage and Lovelace had this idea in mind, they never built a complete working model.