The first modern computer was invented in 1941 by German engineer Konrad Zuse and was called the Z3. It was used to help design German airplanes and missiles. Shortly after, in 1943, the Allied forces developed the Colossus computer to help decode German messages. First generation computers had operating instructions made specifically for each task and used machine language programming, making them difficult to program and limiting versatility. They also used vacuum tubes, which made them very large, and magnetic drums for data storage.