From 69bb628a8b9dad0ee48a44fdd7dffc9f59118f94 Mon Sep 17 00:00:00 2001
From: tildearrow <tildearrow@protonmail.com>
Date: Thu, 10 Nov 2022 04:48:15 -0500
Subject: [PATCH] PC speaker: add PC-98 clock rate options

---
 src/engine/platform/pcspkr.cpp | 12 +++++++++++-
 src/gui/sysConf.cpp            | 16 ++++++++++++++++
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/src/engine/platform/pcspkr.cpp b/src/engine/platform/pcspkr.cpp
index 42a9ac5c..226ee98c 100644
--- a/src/engine/platform/pcspkr.cpp
+++ b/src/engine/platform/pcspkr.cpp
@@ -587,7 +587,17 @@ bool DivPlatformPCSpeaker::keyOffAffectsArp(int ch) {
 }
 
 void DivPlatformPCSpeaker::setFlags(const DivConfig& flags) {
-  chipClock=COLOR_NTSC/3.0;
+  switch (flags.getInt("clockSel",0)) {
+    case 1: // PC-98
+      chipClock=38400*52;
+      break;
+    case 2: // PC-98
+      chipClock=38400*64;
+      break;
+    default: // IBM PC
+      chipClock=COLOR_NTSC/3.0;
+      break;
+  }
   rate=chipClock/PCSPKR_DIVIDER;
   speakerType=flags.getInt("speakerType",0)&3;
   oscBuf->rate=rate;
diff --git a/src/gui/sysConf.cpp b/src/gui/sysConf.cpp
index 79d7344c..f1b6822f 100644
--- a/src/gui/sysConf.cpp
+++ b/src/gui/sysConf.cpp
@@ -683,8 +683,23 @@ bool FurnaceGUI::drawSysConf(int chan, DivSystem type, DivConfig& flags, bool mo
       break;
     }
     case DIV_SYSTEM_PCSPKR: {
+      int clockSel=flags.getInt("clockSel",0);
       int speakerType=flags.getInt("speakerType",0);
 
+      ImGui::Text("Clock rate:");
+      if (ImGui::RadioButton("1.19MHz (PC)",clockSel==0)) {
+        clockSel=0;
+        altered=true;
+      }
+      if (ImGui::RadioButton("1.99MHz (PC-98)",clockSel==1)) {
+        clockSel=1;
+        altered=true;
+      }
+      if (ImGui::RadioButton("2.46MHz (PC-98)",clockSel==2)) {
+        clockSel=2;
+        altered=true;
+      }
+
       ImGui::Text("Speaker type:");
       if (ImGui::RadioButton("Unfiltered",speakerType==0)) {
         speakerType=0;
@@ -705,6 +720,7 @@ bool FurnaceGUI::drawSysConf(int chan, DivSystem type, DivConfig& flags, bool mo
 
       if (altered) {
         e->lockSave([&]() {
+          flags.set("clockSel",clockSel);
           flags.set("speakerType",speakerType);
         });
       }