From a14cca074678fbe319ccc1a704ca0635eed0a3e3 Mon Sep 17 00:00:00 2001
From: Vince Weaver <vincent.weaver@maine.edu>
Date: Wed, 12 Sep 2018 11:50:44 -0400
Subject: [PATCH] fireworks: can toggle sound now

---
 fireworks/fireworks.s | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/fireworks/fireworks.s b/fireworks/fireworks.s
index 54623bb6..a774d800 100644
--- a/fireworks/fireworks.s
+++ b/fireworks/fireworks.s
@@ -287,13 +287,25 @@ check_keyboard:
 
 	lda	KEYPRESS				; 4
 	bpl	no_keypress				; 3
-	jmp	loop_forever
+	jmp	restart
 no_keypress:
 
 	jmp	display_loop				; 3
 
-loop_forever:
-	jmp	loop_forever
+
+	; Restart and toggle sound
+restart:
+	; self mofifying code, flip from bit C030 to bit 0030
+	lda	sound1+2
+	eor	#$C0
+	sta	sound1+2
+
+
+	lda	sound2+2
+	eor	#$C0
+	sta	sound2+2
+
+	jmp	setup_background
 
 
 jump_table: