The equipment, in the early days, when the game was played with music:

“A frame, modeled on a child’s abacus, a frame with several dozen wires on which could be strung glass beads of various sizes, shapes, and colors. The wires corresponded to lines of the music staff, the beads to the time-values of the notes, and so on.”

Matt Webb, S&W, posted 2006-04-06 (talk on 2006-02-23)