Graphic 84, a block that carries him up. It keeps its state in +17: bit 0 while it is moving, bit 1 while it is on the way down, and bit 7, set by the collision code when he (or the heavy block, HEAVY_BLOCK) lands on it (MARK_STOOD_ON).

At rest, it waits for him: landing on it passes his Z step down to it (ADJ_DZ_FOR_OBJ_INTERSECT), it moves, bumps the floor, and with bit 7 set it starts to rise. Rising, it asks for two units a turn, gives him a Z step of 3 and tells his code he is standing on something (bit 2 of PLAYER_BUMPED); it rises only while it keeps bumping into something above it -- him -- so the moment he steps off it turns round. At a height of 176 it stops, and he is given a Z step of -2. On the way down it sinks one a turn until it bumps into something below, and then it is at rest again.

Measured in the simulator in room 2: he landed on it at Z 128 and it rose one unit a turn with him on top, 12 above it; at 176 he fell, pushing the lift down with him faster and faster, and at the floor it started up again, and so on for as long as he stood there.