From bc32809ecb7ad3cce6765f57e11bc9599474daa7 Mon Sep 17 00:00:00 2001
From: tildearrow <tildearrow@protonmail.com>
Date: Fri, 21 Jan 2022 04:27:00 -0500
Subject: [PATCH] fix #46

---
 src/engine/platform/ay.cpp | 12 +++++++-----
 src/engine/playback.cpp    |  2 +-
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/src/engine/platform/ay.cpp b/src/engine/platform/ay.cpp
index 50e58703c..32a923aff 100644
--- a/src/engine/platform/ay.cpp
+++ b/src/engine/platform/ay.cpp
@@ -207,11 +207,13 @@ int DivPlatformAY8910::dispatch(DivCommand c) {
       break;
     }
     case DIV_CMD_STD_NOISE_MODE:
-      chan[c.chan].psgMode=(c.value+1)&7;
-      if (isMuted[c.chan]) {
-        rWrite(0x08+c.chan,0);
-      } else if (chan[c.chan].active) {
-        rWrite(0x08+c.chan,(chan[c.chan].outVol&15)|((chan[c.chan].psgMode&4)<<2));
+      if (c.value<16) {
+        chan[c.chan].psgMode=(c.value+1)&7;
+        if (isMuted[c.chan]) {
+          rWrite(0x08+c.chan,0);
+        } else if (chan[c.chan].active) {
+          rWrite(0x08+c.chan,(chan[c.chan].outVol&15)|((chan[c.chan].psgMode&4)<<2));
+        }
       }
       break;
     case DIV_CMD_STD_NOISE_FREQ:
diff --git a/src/engine/playback.cpp b/src/engine/playback.cpp
index 1e13b1a9d..10af75995 100644
--- a/src/engine/playback.cpp
+++ b/src/engine/playback.cpp
@@ -354,7 +354,7 @@ bool DivEngine::perSystemPostEffect(int ch, unsigned char effect, unsigned char
     case DIV_SYSTEM_AY8930:
       switch (effect) {
         case 0x12: // duty on 8930
-          dispatchCmd(DivCommand(DIV_CMD_STD_NOISE_MODE,ch,0x10+effectVal));
+          dispatchCmd(DivCommand(DIV_CMD_STD_NOISE_MODE,ch,0x10+(effectVal&15)));
           break;
         case 0x20: // mode
           dispatchCmd(DivCommand(DIV_CMD_STD_NOISE_MODE,ch,effectVal&15));