From 961c9773789c2183eafd257bb3afbc3376304724 Mon Sep 17 00:00:00 2001
From: tildearrow <tildearrow@protonmail.com>
Date: Fri, 13 Jan 2023 00:07:56 -0500
Subject: [PATCH] OPM/OPZ: custom clocks

finally
---
 src/engine/platform/arcade.cpp | 8 +++++---
 src/engine/platform/tx81z.cpp  | 7 ++++---
 2 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/src/engine/platform/arcade.cpp b/src/engine/platform/arcade.cpp
index f9a2e7cb..1984e5a1 100644
--- a/src/engine/platform/arcade.cpp
+++ b/src/engine/platform/arcade.cpp
@@ -19,6 +19,7 @@
 
 #include "arcade.h"
 #include "../engine.h"
+#include "../../ta-log.h"
 #include <string.h>
 #include <math.h>
 
@@ -868,17 +869,18 @@ void DivPlatformArcade::setFlags(const DivConfig& flags) {
   switch (flags.getInt("clockSel",0)) {
     case 1:
       chipClock=COLOR_PAL*4.0/5.0;
-      baseFreqOff=12;
       break;
     case 2:
       chipClock=4000000.0;
-      baseFreqOff=-122;
       break;
     default:
       chipClock=COLOR_NTSC;
-      baseFreqOff=0;
       break;
   }
+  CHECK_CUSTOM_CLOCK;
+
+  baseFreqOff=round(768.0*(log((COLOR_NTSC/(double)chipClock))/log(2.0)));
+
   rate=chipClock/64;
   for (int i=0; i<8; i++) {
     oscBuf[i]->rate=rate;
diff --git a/src/engine/platform/tx81z.cpp b/src/engine/platform/tx81z.cpp
index 2b119abb..fa3d4d18 100644
--- a/src/engine/platform/tx81z.cpp
+++ b/src/engine/platform/tx81z.cpp
@@ -941,14 +941,15 @@ void DivPlatformTX81Z::setFlags(const DivConfig& flags) {
   int clockSel=flags.getInt("clockSel",0);
   if (clockSel==2) {
     chipClock=4000000.0;
-    baseFreqOff=-122;
   } else if (clockSel==1) {
     chipClock=COLOR_PAL*4.0/5.0;
-    baseFreqOff=12;
   } else {
     chipClock=COLOR_NTSC;
-    baseFreqOff=0;
   }
+  CHECK_CUSTOM_CLOCK;
+
+  baseFreqOff=round(768.0*(log((COLOR_NTSC/(double)chipClock))/log(2.0)));
+
   rate=chipClock/64;
   for (int i=0; i<8; i++) {
     oscBuf[i]->rate=rate;