From 26e7d2f99001ffaaa809f3002bcee7422c125111 Mon Sep 17 00:00:00 2001
From: Peter Ferrie <peter.ferrie@gmail.com>
Date: Fri, 7 Jun 2019 23:23:29 -0400
Subject: [PATCH] pt3_player: optimize mockingboard writes

---
 pt3_player/interrupt_handler.s |  9 ++++-----
 pt3_player/mockingboard_a.s    | 22 ++++++++++------------
 2 files changed, 14 insertions(+), 17 deletions(-)

diff --git a/pt3_player/interrupt_handler.s b/pt3_player/interrupt_handler.s
index 78691e18..107c14c9 100644
--- a/pt3_player/interrupt_handler.s
+++ b/pt3_player/interrupt_handler.s
@@ -105,15 +105,14 @@ mb_not_13:
 	; address
 	stx	MOCK_6522_ORA1		; put address on PA1		; 4
 	stx	MOCK_6522_ORA2		; put address on PA2		; 4
-	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
+	ldy	#MOCK_AY_LATCH_ADDR	; latch_address for PB1		; 2
+	sty	MOCK_6522_ORB1		; latch_address on PB1          ; 4
+	sty	MOCK_6522_ORB2		; latch_address on PB2		; 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
 	sta	MOCK_6522_ORA1		; put value on PA1		; 4
 	sta	MOCK_6522_ORA2		; put value on PA2		; 4
 	lda	#MOCK_AY_WRITE		;				; 2
@@ -122,7 +121,7 @@ mb_not_13:
 	sty	MOCK_6522_ORB1						; 4
 	sty	MOCK_6522_ORB2						; 4
 								;===========
-								; 	60
+								; 	56
 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 bf8b7cdd..20bd5b8f 100644
--- a/pt3_player/mockingboard_a.s
+++ b/pt3_player/mockingboard_a.s
@@ -74,6 +74,15 @@ reset_ay_both:
 	rts
 
 
+	;=======================================
+	; clear ay -- clear all 14 AY registers
+	; should silence the card
+	;=======================================
+clear_ay_both:
+	ldx	#14
+	lda	#0
+	sta	MB_VALUE
+clear_ay_left_loop:
 ;	Write sequence
 ;	Inactive -> Latch Address -> Inactive -> Write Data -> Inactive
 
@@ -104,19 +113,8 @@ write_ay_both:
 	sty	MOCK_6522_ORB1						; 3
 	sty	MOCK_6522_ORB2						; 3
 
-	rts								; 6
 								;===========
-								;       51
-	;=======================================
-	; clear ay -- clear all 14 AY registers
-	; should silence the card
-	;=======================================
-clear_ay_both:
-	ldx	#14
-	lda	#0
-	sta	MB_VALUE
-clear_ay_left_loop:
-	jsr	write_ay_both
+								;       45
 	dex
 	bpl	clear_ay_left_loop
 	rts