diff --git a/asm_routines/mockingboard_a.s b/asm_routines/mockingboard_a.s
index 29423d46..54d06e19 100644
--- a/asm_routines/mockingboard_a.s
+++ b/asm_routines/mockingboard_a.s
@@ -84,19 +84,19 @@ reset_ay_both:
 
 write_ay_both:
 	; address
-	stx	MOCK_6522_ORA1		; put address on PA
-	lda	#MOCK_AY_LATCH_ADDR	; latch_address on PB
-	sta	MOCK_6522_ORB1
-	lda	#MOCK_AY_INACTIVE	; go inactive
-	sta	MOCK_6522_ORB1
+	stx	MOCK_6522_ORA1		; put address on PA		; 3
+	lda	#MOCK_AY_LATCH_ADDR	; latch_address on PB		; 2
+	sta	MOCK_6522_ORB1						; 3
+	lda	#MOCK_AY_INACTIVE	; go inactive			; 2
+	sta	MOCK_6522_ORB1						; 3
 
 	; value
-	lda	MB_VALUE
-	sta	MOCK_6522_ORA1		; put value on PA
-	lda	#MOCK_AY_WRITE		; write on PB
-	sta	MOCK_6522_ORB1
-	lda	#MOCK_AY_INACTIVE	; go inactive
-	sta	MOCK_6522_ORB1
+	lda	MB_VALUE						; 3
+	sta	MOCK_6522_ORA1		; put value on PA		; 3
+	lda	#MOCK_AY_WRITE		; write on PB			; 2
+	sta	MOCK_6522_ORB1						; 3
+	lda	#MOCK_AY_INACTIVE	; go inactive			; 2
+	sta	MOCK_6522_ORB1						; 3
 
 	;=======================
 	; Write Left AY-3-8910
@@ -104,22 +104,23 @@ write_ay_both:
 
 ;write_ay_left:
 	; address
-	stx	MOCK_6522_ORA2		; put address on PA
-	lda	#MOCK_AY_LATCH_ADDR	; latch_address on PB
-	sta	MOCK_6522_ORB2
-	lda	#MOCK_AY_INACTIVE	; go inactive
-	sta	MOCK_6522_ORB2
+	stx	MOCK_6522_ORA2		; put address on PA		; 3
+	lda	#MOCK_AY_LATCH_ADDR	; latch_address on PB		; 2
+	sta	MOCK_6522_ORB2						; 3
+	lda	#MOCK_AY_INACTIVE	; go inactive			; 2
+	sta	MOCK_6522_ORB2						; 3
 
 	; value
-	lda	MB_VALUE
-	sta	MOCK_6522_ORA2		; put value on PA
-	lda	#MOCK_AY_WRITE		; write on PB
-	sta	MOCK_6522_ORB2
-	lda	#MOCK_AY_INACTIVE	; go inactive
-	sta	MOCK_6522_ORB2
-
-	rts
+	lda	MB_VALUE						; 3
+	sta	MOCK_6522_ORA2		; put value on PA		; 3
+	lda	#MOCK_AY_WRITE		; write on PB			; 2
+	sta	MOCK_6522_ORB2						; 3
+	lda	#MOCK_AY_INACTIVE	; go inactive			; 2
+	sta	MOCK_6522_ORB2						; 3
 
+	rts								; 6
+								;===========
+								;       61
 	;=======================================
 	; clear ay -- clear all 14 AY registers
 	; should silence the card
diff --git a/chiptune_player/chiptune_player.s b/chiptune_player/chiptune_player.s
index f0edbfda..b93ab0c6 100644
--- a/chiptune_player/chiptune_player.s
+++ b/chiptune_player/chiptune_player.s
@@ -302,10 +302,11 @@ mb_not_13:
 	and	#$f							; 2
 	sta	REGISTER_DUMP,X						; 4
 
-					; INLINE this?
+					; INLINE this (could save 72 cycles)
 	jsr	write_ay_both		; assume 3 channel (not six)	; 6
 					; so write same to both
 					; left/right
+									; 61
 
 	clc				; point to next interleaved	; 2
 	lda	INH			; page by adding $300		; 3
@@ -341,7 +342,7 @@ chunk_good:
 done_interrupt:
 	pla			; restore a				; 4
 
-	rti								; 6
+	rti			; return from interrupt			; 6
 
 
 	;=================
diff --git a/chiptune_player/zp.inc b/chiptune_player/zp.inc
index 4ec04f7f..50f78371 100644
--- a/chiptune_player/zp.inc
+++ b/chiptune_player/zp.inc
@@ -51,6 +51,22 @@ SCREEN_Y	EQU $62
 				;DY_I		EQU $6E
 				;DY_F		EQU $6F
 
+REGISTER_DUMP	EQU $70
+A_FINE_TONE	EQU $70
+A_COARSE_TONE	EQU $71
+B_FINE_TONE	EQU $72
+B_COARSE_TONE	EQU $73
+C_FINE_TONE	EQU $74
+C_COARSE_TONE	EQU $75
+NOISE		EQU $76
+ENABLE		EQU $77
+A_VOLUME	EQU $78
+B_VOLUME	EQU $79
+C_VOLUME	EQU $7A
+ENVELOPE_FINE	EQU $7B
+ENVELOPE_COARSE	EQU $7C
+ENVELOPE_SHAPE  EQU $7D
+
 				;SPACEY_I	EQU $70
 				;SPACEY_F	EQU $71
 				;CY_I		EQU $72
@@ -68,9 +84,7 @@ SCREEN_Y	EQU $62
 				;NUM1L		EQU $7E
 				;NUM1H		EQU $7F
 
-A_VOLUME	EQU $80
-B_VOLUME	EQU $81
-C_VOLUME	EQU $82
+
 A_COLOR		EQU $83
 B_COLOR		EQU $84
 C_COLOR		EQU $85