"Butterfinger" from the Stanford AI Project describes a robot that integrates a six degree of freedom prosthetic arm with a TV-based vision system to enable it to separate a collection of blocks and stack them into stacks of red and blue blocks. Feedback is by a sensor in the fingers that can detect if, for example, the block it has just placed is not where it placed it and by visual examination that can identify modest placement errors. The work was done in fall 1967 and the film is produced and directed by Gary Feldman. The end of the film also mentions Karl Pingle, Jeff Singer and Bill Wichman as programmers and developers, and the camera operator was Randy Benedict.