Nothing happens, when the player isn't above the stairs, the table in ram is restored.
the stairs diagonal speech is similar but with a small difference:
the player can't go up to the stairs, when the player go to left or right the stairs, do a diagonal movement of 2 blocks!
083756A4, this table is consists of 9 "entries", one for each movement. Each part is composed of a 32bit word. 9 movement??? yes: right, left, up, down, firm and 4 for diagonal movement!
the routine, through the coordinates of the player, is able to identify the behavior of the block to the right or left of the player.
if it has particular behavior, change the bytes movement (right word or left word). after repoint table in RAM, you can write bytes!