You know it’s time to clean your computer, when it won’t turn on due to an infestation of cockroaches inside the case. Unfortunately, the computers you’re about to see only get worse, but there is one surprise, a creation that will make you feel at home. Continue reading to see them all.

The first electronic digital computers were developed between 1940 and 1945. Originally they were the size of a large room, consuming as much power as several hundred modern personal computers (PCs). In this era mechanical analog computers were used for military applications.