Mark's description is
missing, so I'll briefly describe his project. His
automated Tic Tac Toe mechanism, similar to Ken
Drewe's automated checkers, moved "X's" and "O's" around the board
as indicated by his program to automate the game of "Tic Tac
Toe." An interesting difference in his design was how he decided
to grip and release the playing pieces. In the chess
mechanism, Ken used an electromagnet to pick up his
checkers. Mark decided to use another approach in his Tic
Tac Toe game: Each of the "X's" and "O's" had magnets
cleverly built into their design that attached themselves to his
gripper, also an electromagnet, when they came into close proximity to
it. In order to "release" the pieces, Mark energized the
electromagnet to the opposite polarity from the pieces, thus repelling them and effectively
releasing them from the gripper!