Knight Lore: Routine at C685

C685: Start a portcullis falling

Used by the routine at upd_8.

Input
A	the number of falls so far
HL	$5BAF

init_portcullis_down

C685

INC A

one more fall

C686

LD ($5BB0),A

C689

SET 0,(IX+$00)

type 9: moving

C68D

LD (IX+$0B),$FF

dz = -1