diff --git a/pt3_player/interrupt_handler.s b/pt3_player/interrupt_handler.s
index b5bfb733..e48d7716 100644
--- a/pt3_player/interrupt_handler.s
+++ b/pt3_player/interrupt_handler.s
@@ -99,9 +99,9 @@ mb_not_13:
 	lda	#MOCK_AY_LATCH_ADDR	; latch_address for PB1		; 2
 	sta	MOCK_6522_ORB1		; latch_address on PB1          ; 4
 	sta	MOCK_6522_ORB2		; latch_address on PB2		; 4
-	lda	#MOCK_AY_INACTIVE	; go inactive			; 2
-	sta	MOCK_6522_ORB1						; 4
-	sta	MOCK_6522_ORB2						; 4
+	ldy	#MOCK_AY_INACTIVE	; go inactive			; 2
+	sty	MOCK_6522_ORB1						; 4
+	sty	MOCK_6522_ORB2						; 4
 
         ; value
 	lda	AY_REGISTERS,X		; load register value		; 4
@@ -110,11 +110,10 @@ mb_not_13:
 	lda	#MOCK_AY_WRITE		;				; 2
 	sta	MOCK_6522_ORB1		; write on PB1			; 4
 	sta	MOCK_6522_ORB2		; write on PB2			; 4
-	lda	#MOCK_AY_INACTIVE	; go inactive			; 2
-	sta	MOCK_6522_ORB1						; 4
-	sta	MOCK_6522_ORB2						; 4
+	sty	MOCK_6522_ORB1						; 4
+	sty	MOCK_6522_ORB2						; 4
 								;===========
-								; 	62
+								; 	60
 mb_no_write:
 	inx				; point to next register	; 2
 	cpx	#14			; if 14 we're done		; 2
diff --git a/pt3_player/mockingboard_a.s b/pt3_player/mockingboard_a.s
index 67ddca70..bf8b7cdd 100644
--- a/pt3_player/mockingboard_a.s
+++ b/pt3_player/mockingboard_a.s
@@ -90,9 +90,9 @@ write_ay_both:
 	lda	#MOCK_AY_LATCH_ADDR	; latch_address on PB1		; 2
 	sta	MOCK_6522_ORB1		; latch_address on PB1		; 3
 	sta	MOCK_6522_ORB2		; latch_address on PB2		; 3
-	lda	#MOCK_AY_INACTIVE	; go inactive			; 2
-	sta	MOCK_6522_ORB1						; 3
-	sta	MOCK_6522_ORB2						; 3
+	ldy	#MOCK_AY_INACTIVE	; go inactive			; 2
+	sty	MOCK_6522_ORB1						; 3
+	sty	MOCK_6522_ORB2						; 3
 
 	; value
 	lda	MB_VALUE						; 3
@@ -101,13 +101,12 @@ write_ay_both:
 	lda	#MOCK_AY_WRITE		;				; 2
 	sta	MOCK_6522_ORB1		; write on PB1			; 3
 	sta	MOCK_6522_ORB2		; write on PB2			; 3
-	lda	#MOCK_AY_INACTIVE	; go inactive			; 2
-	sta	MOCK_6522_ORB1						; 3
-	sta	MOCK_6522_ORB2						; 3
+	sty	MOCK_6522_ORB1						; 3
+	sty	MOCK_6522_ORB2						; 3
 
 	rts								; 6
 								;===========
-								;       53
+								;       51
 	;=======================================
 	; clear ay -- clear all 14 AY registers
 	; should silence the card
diff --git a/pt3_player/pt3_timer.s b/pt3_player/pt3_timer.s
index 5ef887f7..6775d4c9 100644
--- a/pt3_player/pt3_timer.s
+++ b/pt3_player/pt3_timer.s
@@ -411,9 +411,9 @@ mb_not_13:
 	lda	#MOCK_AY_LATCH_ADDR	; latch_address for PB1		; 2
 	sta	MOCK_6522_ORB1		; latch_address on PB1          ; 4
 	sta	MOCK_6522_ORB2		; latch_address on PB2		; 4
-	lda	#MOCK_AY_INACTIVE	; go inactive			; 2
-	sta	MOCK_6522_ORB1						; 4
-	sta	MOCK_6522_ORB2						; 4
+	ldy	#MOCK_AY_INACTIVE	; go inactive			; 2
+	sty	MOCK_6522_ORB1						; 4
+	sty	MOCK_6522_ORB2						; 4
 
         ; value
 	lda	AY_REGISTERS,X		; load register value		; 4
@@ -422,11 +422,10 @@ mb_not_13:
 	lda	#MOCK_AY_WRITE		;				; 2
 	sta	MOCK_6522_ORB1		; write on PB1			; 4
 	sta	MOCK_6522_ORB2		; write on PB2			; 4
-	lda	#MOCK_AY_INACTIVE	; go inactive			; 2
-	sta	MOCK_6522_ORB1						; 4
-	sta	MOCK_6522_ORB2						; 4
+	sty	MOCK_6522_ORB1						; 4
+	sty	MOCK_6522_ORB2						; 4
 								;===========
-								; 	62
+								; 	60
 mb_no_write:
 	inx				; point to next register	; 2
 	cpx	#14			; if 14 we're done		; 2