From 4aef32bccabb2030569a76d66ad5a932f06db4c8 Mon Sep 17 00:00:00 2001
From: qwertymodo <qwertymodo@qwertymodo.com>
Date: Fri, 27 Sep 2019 20:34:21 -0700
Subject: [PATCH] Don't allow SPC mute/unmute commands to be executed during
 NMI

---
 msu.asm | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/msu.asm b/msu.asm
index 153b9a1..d82cd97 100644
--- a/msu.asm
+++ b/msu.asm
@@ -530,7 +530,10 @@ command_f1:
 
 command_f0:
     CPX !VAL_COMMAND_STOP_PLAYBACK : !BLT load_track
-    JML spc_continue
+    CPX !VAL_COMMAND_MUTE_SPC : BEQ +       ; Don't allow executing the mute/umute
+    CPX !VAL_COMMAND_UNMUTE_SPC : BNE ++    ; commands during NMI like this
+        + : LDA.b #$00 : STA !REG_MUSIC_CONTROL
+    ++ : JML spc_continue
 
 load_track:
     CPX !REG_CURRENT_MSU_TRACK : BNE +