Abacus is the first counting device, developed by Chinese and Egyptians, 2500 years ago. It was a long journey to get to here from Abacus. This note contains a brief description on how computers have evolved.
Mark I is the first electro-mechanical computer developed by Howard Aiken in 1937. There after many computers were invented. This note provide us an information about the series of Electro-Mechanical Computers invented after Mark I.