The earliest form of Minesweeper was a gambling game that was briefly popular during the 1950s. The player would buy a punchboard, which was made of paper and cardboard. The top layer was cardboard with a square lattice of holes, each of which corresponded to one of the buttons in the present-day Minesweeper game. The holes were blocked by a layer of paper underneath. The player could choose to punch the paper through any hole, and would then see what was printed on a third layer of cardboard underneath that hole. It revealed color-coded information equivalent to that which Minesweeper reveals from a button-click.