This document provides a summary of the history of early computers from ancient counting tools like the Ishango bone dated to 20,000 BC to the development of Boolean logic in the 19th century. Some of the key events and inventions discussed include the abacus from 2500 BC, the Antikythera mechanism from 150-100 BC, the Pascaline mechanical calculator from 1642, Gottfried Leibniz's Stepped Reckoner mechanical calculator from 1672-1694, Charles Babbage's Analytical Engine design from 1837, the first general purpose programmable computer, Ada Lovelace's notes on the Analytical Engine which are considered the first computer program, George Boole's development of