Tinkertoys and tic-tac-toe, p. 120indirectly kicks an "output duck," a bird-shaped construction. The output duck swings down from its perch so that its beak points at a number- which identifies the computer's next move in a game of tic~tac-toe. What precisely does the read head scan as it feels its way down the monolith? Nothing less than 48 rows of Tinkertoy "memory spindles" encoding all the critical combinations of X's and O's
