Color and sound in algorithm animation

The techniques developed by M. M. Brown and R. Sedgewick (1985) in using the Balsa algorithm-animation system are reviewed. Techniques that focus on color and sound, areas just opening up in workstation-based interactive algorithm-animation systems, are described. Color is used for encoding the state of data structures, highlighting activity, trying multiple views together, emphasizing patterns, and making an algorithm´s history visible in a single static image. Sound is used for reinforcing visuals, conveying patterns, replacing visuals, and signaling exceptional conditions. The techniques are based on work done with the Zeus algorithm-animation system. Six screen dumps from six different algorithm animations that are representative of the was Zeus was used are presented.<>