Used by the routine at DEADLY_BOBBER.

Used by graphic 86 through DEADLY_BOBBER, which makes it deadly first; graphic 85 comes here directly, but no room places one. It keeps its state in bit 2 of +D, which the kill bits (5 to 7) leave free: clear while it falls, set while it rises.

Falling, it drops one unit a turn; when it lands on something it starts rising, one unit a turn (the 2 it stores on landing is overwritten with 1 before any move uses it; measured in room 88: one unit a turn from the first), until its height reaches 176, when it falls again. If something above stops it rising, it falls at once. When the player (or the heavy block) is standing on it the rise is three a turn; a jump by him clears that.

Measured in the simulator in room 11 (graphic 86, nothing on it): it rose one unit a turn to 176 and fell back one a turn to where it had landed, over and over.