Batty: Routine at C064

C064: Sounds: Find Empty Slot

Used by the routines at 965D and 974A.
Sounds_FindEmptySlot	C064	LD IX,$C0B8	IX=Sounds_Queue.
There are 05 slots in total, obviously the first slot is accounted for on the first pass, so only 04 loops are necessary.
	C068	LD B,$04	B=04 (counter).
	C06A	LD DE,$0007	Each slot is 0007 bytes.
Found an empty slot, so return.
Sounds_FindEmptySlot_Loop	C06D	LD A,(IX+$00)	Return if *IX+00 is zero.
	C070	AND A
	C071	RET Z
	C072	ADD IX,DE	IX+=DE.
	C074	DJNZ Sounds_FindEmptySlot_Loop	Decrease counter by one and loop back to Sounds_FindEmptySlot_Loop until counter is zero.
	C076	RET	Return.