From 7bafd10348a8315a9a1cbb3dfd095a40e19cd2ea Mon Sep 17 00:00:00 2001
From: =?utf8?q?Herm=C3=A8s=20B=C3=A9lusca-Ma=C3=AFto?=
 <hermes.belusca-maito@reactos.org>
Date: Sat, 27 Sep 2014 15:33:27 +0000
Subject: [PATCH 1/1] [NTVDM] - When writing to port 61h, reset the PIT 2 gate
 only when needed. - When the PIT 2 out signal is set, notify the speaker when
 there is really a change. - PC speaker: Do not replay the same sound if it is
 the same.

svn path=/trunk/; revision=64345
---
 reactos/subsystems/ntvdm/emulator.c         | 22 +++++++++++----------
 reactos/subsystems/ntvdm/hardware/speaker.c | 19 ++++++++++++++++--
 2 files changed, 29 insertions(+), 12 deletions(-)

diff --git a/reactos/subsystems/ntvdm/emulator.c b/reactos/subsystems/ntvdm/emulator.c
index 42b5f19c8d4..ff01f259810 100644
--- a/reactos/subsystems/ntvdm/emulator.c
+++ b/reactos/subsystems/ntvdm/emulator.c
@@ -262,7 +262,7 @@ static BYTE WINAPI Port61hRead(ULONG Port)
 
 static VOID WINAPI Port61hWrite(ULONG Port, BYTE Data)
 {
-    // BOOLEAN SpeakerChange = FALSE;
+    // BOOLEAN SpeakerStateChange = FALSE;
     BYTE OldPort61hState = Port61hState;
 
     /* Only the four lowest bytes can be written */
@@ -271,18 +271,17 @@ static VOID WINAPI Port61hWrite(ULONG Port, BYTE Data)
     if ((OldPort61hState ^ Port61hState) & 0x01)
     {
         DPRINT("PIT 2 Gate %s\n", Port61hState & 0x01 ? "on" : "off");
-        // SpeakerChange = TRUE;
+        PitSetGate(2, !!(Port61hState & 0x01));
+        // SpeakerStateChange = TRUE;
     }
 
-    PitSetGate(2, !!(Port61hState & 0x01));
-
     if ((OldPort61hState ^ Port61hState) & 0x02)
     {
         /* There were some change for the speaker... */
         DPRINT("Speaker %s\n", Port61hState & 0x02 ? "on" : "off");
-        // SpeakerChange = TRUE;
+        // SpeakerStateChange = TRUE;
     }
-    // if (SpeakerChange) SpeakerChange();
+    // if (SpeakerStateChange) SpeakerChange();
     SpeakerChange();
 }
 
@@ -316,7 +315,7 @@ static VOID WINAPI PitChan1Out(LPVOID Param, BOOLEAN State)
 
 static VOID WINAPI PitChan2Out(LPVOID Param, BOOLEAN State)
 {
-    // BYTE OldPort61hState = Port61hState;
+    BYTE OldPort61hState = Port61hState;
 
 #if 0
     if (State)
@@ -332,9 +331,12 @@ static VOID WINAPI PitChan2Out(LPVOID Param, BOOLEAN State)
 #else
     Port61hState = (Port61hState & 0xDF) | (State << 5);
 #endif
-    DPRINT("Speaker PIT out\n");
-    // if ((OldPort61hState ^ Port61hState) & 0x20)
-        // SpeakerChange();
+
+    if ((OldPort61hState ^ Port61hState) & 0x20)
+    {
+        DPRINT("PitChan2Out -- Port61hState changed\n");
+        SpeakerChange();
+    }
 }
 
 
diff --git a/reactos/subsystems/ntvdm/hardware/speaker.c b/reactos/subsystems/ntvdm/hardware/speaker.c
index 542e57d8b93..46eb09e0672 100644
--- a/reactos/subsystems/ntvdm/hardware/speaker.c
+++ b/reactos/subsystems/ntvdm/hardware/speaker.c
@@ -29,6 +29,9 @@ static HANDLE hBeep = NULL;
 
 /* PRIVATE FUNCTIONS **********************************************************/
 
+static DWORD OldReloadValue = 0;
+static PIT_MODE OldMode = 0;
+
 /* PUBLIC FUNCTIONS ***********************************************************/
 
 VOID SpeakerChange(VOID)
@@ -47,9 +50,18 @@ VOID SpeakerChange(VOID)
         DWORD PitChannel2ReloadValue = PitChannel2->ReloadValue;
         if (PitChannel2ReloadValue == 0) PitChannel2ReloadValue = 65536;
 
+        DPRINT("(1) PitChannel2(Bcd = %s, Mode = %d ; ReloadValue = %d)\n", PitChannel2->Bcd ? "true" : "false", PitChannel2->Mode, PitChannel2ReloadValue);
+
+        if (OldMode == PitChannel2->Mode && OldReloadValue == PitChannel2ReloadValue)
+            return;
+
+        OldMode = PitChannel2->Mode;
+        OldReloadValue = PitChannel2ReloadValue;
+
+        DPRINT("(2) PitChannel2(Bcd = %s, Mode = %d ; ReloadValue = %d)\n", PitChannel2->Bcd ? "true" : "false", PitChannel2->Mode, PitChannel2ReloadValue);
+
         /* Set beep data */
-        BeepSetParameters.Frequency = (PIT_BASE_FREQUENCY / PitChannel2ReloadValue)
-                                          /* * (PitChannel2->Mode == PIT_MODE_SQUARE_WAVE ? 2 : 1) */;
+        BeepSetParameters.Frequency = (PIT_BASE_FREQUENCY / PitChannel2ReloadValue);
         BeepSetParameters.Duration  = INFINITE;
 
         /* Send the beep */
@@ -78,6 +90,9 @@ VOID SpeakerChange(VOID)
         IO_STATUS_BLOCK IoStatusBlock;
         BEEP_SET_PARAMETERS BeepSetParameters;
 
+        OldMode = 0;
+        OldReloadValue = 0;
+
         /* Set beep data */
         BeepSetParameters.Frequency = 0x00;
         BeepSetParameters.Duration  = 0x00;
-- 
2.17.1