This is one example of many castles in the medieval time period. There were many parts to a castle. But, it depended on how the castle was built to recognize parts that did and did not appear on the castle built.
Like spray paint, these markers give off volatile organic compounds. Some of the most recently made permanent markers are made from recycled plastic.[citation needed] The permanent marker was invented in 1952 by Sidney Rosenthal.
The first light pen was created around 1955 as part of the Whirlwind project at MIT. During the 1960s light pens were common on graphics terminals such as the IBM 2250, and were also available for the IBM 3270 text-only terminal. The light pen was used in the early 1980s.