That’s not the only difference. ENIAC weighed more than 30 tons, filled an 1,800-square-foot room and included 6,000 manual switches. It used so much electricity that it sometimes caused power shortages in its home city of Philadelphia. By contrast, a notebook PC today might weigh in at about 3 pounds. You may know that “booting” your computer means starting it up. But did you know the word comes from “pulling yourself up by your bootstraps”? That’s an expression that means taking charge of yourself, which is what a computer seems to do when it starts up! The term “bug” has been used for problems in machinery since electricity was invented. But the first computer bug was actually a moth! In 1945, a computer being tested at Harvard University stalled when a moth got caught inside. The engineers taped the moth into their computer log with the note, “First actual case of bug being found.”