From d7ec3b13c5db274b7dfde0385311c74d118bf8fd Mon Sep 17 00:00:00 2001
From: tildearrow <tildearrow@protonmail.com>
Date: Fri, 13 May 2022 22:43:00 -0500
Subject: [PATCH] ADPCM-B: fixes to compatible mode

---
 src/engine/platform/ym2608.cpp  | 11 +++++++----
 src/engine/platform/ym2610.cpp  |  7 +++++--
 src/engine/platform/ym2610b.cpp |  7 +++++--
 3 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/src/engine/platform/ym2608.cpp b/src/engine/platform/ym2608.cpp
index 31ecba9c..ec41a8c6 100644
--- a/src/engine/platform/ym2608.cpp
+++ b/src/engine/platform/ym2608.cpp
@@ -797,10 +797,11 @@ int DivPlatformYM2608::dispatch(DivCommand c) {
           int end=s->offB+s->lengthB-1;
           immWrite(0x104,(end>>5)&0xff);
           immWrite(0x105,(end>>13)&0xff);
-          immWrite(0x101,isMuted[c.chan]?0:(chan[c.chan].pan<<6));
-          immWrite(0x100,(s->loopStart>=0)?0x90:0x80); // start/repeat
-          chan[c.chan].baseFreq=(((unsigned int)s->rate)<<16)/(chipClock/144);
-          chan[c.chan].freqChanged=true;
+          immWrite(0x101,(isMuted[c.chan]?0:(chan[c.chan].pan<<6))|2);
+          immWrite(0x100,(s->loopStart>=0)?0xb0:0xa0); // start/repeat
+          int freq=(65536.0*(double)s->rate)/((double)chipClock/144.0);
+          immWrite(0x109,freq&0xff);
+          immWrite(0x10a,(freq>>8)&0xff);
         }
         break;
       }
@@ -942,6 +943,7 @@ int DivPlatformYM2608::dispatch(DivCommand c) {
       break;
     }
     case DIV_CMD_PITCH: {
+      if (c.chan==15 && !chan[c.chan].furnacePCM) break;
       chan[c.chan].pitch=c.value;
       chan[c.chan].freqChanged=true;
       break;
@@ -1022,6 +1024,7 @@ int DivPlatformYM2608::dispatch(DivCommand c) {
       iface.sampleBank=sampleBank;
       break;
     case DIV_CMD_LEGATO: {
+      if (c.chan==15 && !chan[c.chan].furnacePCM) break;
       chan[c.chan].baseFreq=NOTE_OPNB(c.chan,c.value);
       chan[c.chan].freqChanged=true;
       break;
diff --git a/src/engine/platform/ym2610.cpp b/src/engine/platform/ym2610.cpp
index 397f6a8f..ba29263b 100644
--- a/src/engine/platform/ym2610.cpp
+++ b/src/engine/platform/ym2610.cpp
@@ -840,8 +840,9 @@ int DivPlatformYM2610::dispatch(DivCommand c) {
           immWrite(0x15,end>>16);
           immWrite(0x11,isMuted[c.chan]?0:(chan[c.chan].pan<<6));
           immWrite(0x10,(s->loopStart>=0)?0x90:0x80); // start/repeat
-          chan[c.chan].baseFreq=(((unsigned int)s->rate)<<16)/(chipClock/144);
-          chan[c.chan].freqChanged=true;
+          int freq=(65536.0*(double)s->rate)/((double)chipClock/144.0);
+          immWrite(0x19,freq&0xff);
+          immWrite(0x1a,(freq>>8)&0xff);
         }
         break;
       }
@@ -997,6 +998,7 @@ int DivPlatformYM2610::dispatch(DivCommand c) {
       break;
     }
     case DIV_CMD_PITCH: {
+      if (c.chan==13 && !chan[c.chan].furnacePCM) break;
       chan[c.chan].pitch=c.value;
       chan[c.chan].freqChanged=true;
       break;
@@ -1077,6 +1079,7 @@ int DivPlatformYM2610::dispatch(DivCommand c) {
       iface.sampleBank=sampleBank;
       break;
     case DIV_CMD_LEGATO: {
+      if (c.chan==13 && !chan[c.chan].furnacePCM) break;
       chan[c.chan].baseFreq=NOTE_OPNB(c.chan,c.value);
       chan[c.chan].freqChanged=true;
       break;
diff --git a/src/engine/platform/ym2610b.cpp b/src/engine/platform/ym2610b.cpp
index cd40fe13..b5afce5e 100644
--- a/src/engine/platform/ym2610b.cpp
+++ b/src/engine/platform/ym2610b.cpp
@@ -818,8 +818,9 @@ int DivPlatformYM2610B::dispatch(DivCommand c) {
           immWrite(0x15,end>>16);
           immWrite(0x11,isMuted[c.chan]?0:(chan[c.chan].pan<<6));
           immWrite(0x10,(s->loopStart>=0)?0x90:0x80); // start/repeat
-          chan[c.chan].baseFreq=(((unsigned int)s->rate)<<16)/(chipClock/144);
-          chan[c.chan].freqChanged=true;
+          int freq=(65536.0*(double)s->rate)/((double)chipClock/144.0);
+          immWrite(0x19,freq&0xff);
+          immWrite(0x1a,(freq>>8)&0xff);
         }
         break;
       }
@@ -975,6 +976,7 @@ int DivPlatformYM2610B::dispatch(DivCommand c) {
       break;
     }
     case DIV_CMD_PITCH: {
+      if (c.chan==15 && !chan[c.chan].furnacePCM) break;
       chan[c.chan].pitch=c.value;
       chan[c.chan].freqChanged=true;
       break;
@@ -1055,6 +1057,7 @@ int DivPlatformYM2610B::dispatch(DivCommand c) {
       iface.sampleBank=sampleBank;
       break;
     case DIV_CMD_LEGATO: {
+      if (c.chan==15 && !chan[c.chan].furnacePCM) break;
       chan[c.chan].baseFreq=NOTE_OPNB(c.chan,c.value);
       chan[c.chan].freqChanged=true;
       break;