Stairs/DV

All but cut copper stairs:
Bits 	Description
0x10x2	A two-bit field containing a value from 0 to 3 specifying the direction of the stairs' full-block side:
* 0: East
* 1: West
* 2: South
* 3: North
0x4 	Set if stairs are upside-down
0x8 	(unused)