CRC Description of HotDraw

With the expansion of Memory as Computation we found the need for a better way to talk about programs. We stepped away from the computer, return to paper, but chose index cards, long used by authors to organize complex subjects.

Each index card would represent the entities of a given class. They could be handled while considering how the entities would work together. With one card in hand, it represented an instance, but on the table, organized with others, it represented all instances of the class.

The first ever CRC cards were made to represent an interactive drawing program called Hot Draw. These cards have been scanned and made available online. Other graphic editors have been built from this design. page