From 79e7fca8242ad7a04a75f758b4071c9342229cec Mon Sep 17 00:00:00 2001
From: Peter Ferrie <peter.ferrie@gmail.com>
Date: Sat, 1 Jun 2019 00:07:00 -0400
Subject: [PATCH] optimize mockingboard code

---
 pt3_player/mockingboard_a.s | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/pt3_player/mockingboard_a.s b/pt3_player/mockingboard_a.s
index fff7ca78..67ddca70 100644
--- a/pt3_player/mockingboard_a.s
+++ b/pt3_player/mockingboard_a.s
@@ -66,6 +66,7 @@ reset_ay_both:
 	; Reset Right AY-3-8910
 	;======================
 ;reset_ay_right:
+;could be merged with both
 	lda	#MOCK_AY_RESET
 	sta	MOCK_6522_ORB2
 	lda	#MOCK_AY_INACTIVE
@@ -164,6 +165,41 @@ mb_not_in_this_slot:
 	ldx	#00
 	beq	done_mb_detect
 
+;alternative MB detection from Nox Archaist
+;	lda	#$04
+;	sta	MB_ADDRL
+;	ldx	#$c7
+;
+;find_mb:
+;	stx	MB_ADDRH
+;
+;	;detect sound I
+;
+;	sec
+;	ldy	#$00
+;	lda	(MB_ADDRL), y
+;	sbc	(MB_ADDRL), y
+;	cmp	#$05
+;	beq	found_mb
+;	dex
+;	cpx	#$c0
+;	bne	find_mb
+;	ldx	#$00 ;no mockingboard found
+;	rts
+;
+;found_mb:
+;	ldx	#$01 ;mockingboard found
+;	rts
+;
+;	;optionally detect sound II
+;
+;	sec
+;	ldy	#$80
+;	lda	(MB_ADDRL), y
+;	sbc	(MB_ADDRL), y
+;	cmp	#$05
+;	beq	found_mb
+
 
 	;=======================================
 	; Detect a Mockingboard card in Slot4