FACTUAL REFERENCE
CAMS: SHAPE AS INSTRUCTION

A cam converts rotation into a controlled motion determined by its profile.

Imagine a follower resting against a rotating cam. Where the cam rises, the
follower rises. Where it falls, the follower falls. A carefully shaped cam can
therefore encode timing and displacement around a full rotation.

Multiple cams on one shaft can coordinate several actions.

This is one of the clearest examples of a "program" existing as physical shape.
The cam does not read instructions. Its geometry IS the instruction.

In an automaton, cams can coordinate arms, head, eyes, pen position, bell hammers,
or other mechanisms. In a later computer, a sequence may be encoded in bits. In a
cam machine, the sequence is encoded in metal.