Applied patch #725152 - Sky Music driver by LavosSpawn

svn-id: r7069

9 files changed, 746 insertions, 5 deletions

diff --git a/sky/cd_intro.cpp b/sky/cd_intro.cpp
index b4561b9456..a5901f469b 100644
--- a/sky/cd_intro.cpp
+++ b/sky/cd_intro.cpp
@@ -822,7 +822,7 @@ void SkyState::doCDIntro() {
 	cd2_seq_data_1 = _skyDisk->loadFile(cd_104, NULL);
 	WAIT_SEQUENCE; //103
 
-	//fn_start_music(2);
+	_music->startMusic(2);
 	fnFadeDown(0);
 	COPY_SCREEN;
 	showScreen();
diff --git a/sky/intro.cpp b/sky/intro.cpp
index fc24158410..ccbec1082f 100644
--- a/sky/intro.cpp
+++ b/sky/intro.cpp
@@ -237,12 +237,12 @@ void SkyState::intro(void) {
 	_workScreen = _skyDisk->loadFile(60112, NULL); //while virgin screen is up, load rev screen
 	_tempPal = _skyDisk->loadFile(60113, NULL);
 
-	//loadSectionMusic(0);
+	_music->loadSectionMusic(0);
 	
 	delay(3000); //keep virgin screen up for 3 seconds
 
 	//if (!isCDVersion(_gameVersion))
-	//	fn_start_music();
+	//	_music->startMusic(1);
 	
 	delay(3000); //and another 3 seconds.
 	fnFadeDown(0); //remove virgin screen
diff --git a/sky/module.mk b/sky/module.mk
index 03d17ef31e..99c9f06d99 100644
--- a/sky/module.mk
+++ b/sky/module.mk
@@ -11,6 +11,8 @@ MODULE_OBJS = \
 	sky/rnc_deco.o \
 	sky/grid.o \
 	sky/sound.o \
+	sky/skychannel.o \
+	sky/skymusic.o \
 
 # Include common rules 
 include common.rules
diff --git a/sky/sky.cpp b/sky/sky.cpp
index 7fcddd6e71..0e9dc2239f 100644
--- a/sky/sky.cpp
+++ b/sky/sky.cpp
@@ -83,6 +83,7 @@ void SkyState::go() {
 		_dump_file = stdout;
 
 	initialise();
+	
 	if (!isDemo(_gameVersion) || isCDVersion(_gameVersion))
 		intro();
 	
@@ -95,11 +96,10 @@ void SkyState::initialise(void) {
 
 	//initialise_memory();
 	initTimer();
-	//init_music(); 
 
 	_sound = new SkySound(_mixer);
-
 	_skyDisk = new SkyDisk(_gameDataPath);
+	_music = new SkyMusic(_mixer,_skyDisk);
 	_gameVersion = _skyDisk->determineGameVersion();
 	_skyText = getSkyText();
 	
diff --git a/sky/sky.h b/sky/sky.h
index 9386f79e7c..24d9ec5e7d 100644
--- a/sky/sky.h
+++ b/sky/sky.h
@@ -30,6 +30,7 @@
 #include "sky/sound.h"
 #include "sky/text.h"
 #include "sky/disk.h"
+#include "sky/skymusic.h"
 
 class SkyState : public Engine {
 	void errorString(const char *buf_input, char *buf_output);
@@ -67,6 +68,7 @@ protected:
 
 	SkySound *_sound;
 	SkyDisk *_skyDisk;
+	SkyMusic *_music;
 	
 	byte *_workScreen;
 	byte *_backScreen;
diff --git a/sky/skychannel.cpp b/sky/skychannel.cpp
new file mode 100644
index 0000000000..07b2001735
--- /dev/null
+++ b/sky/skychannel.cpp
@@ -0,0 +1,310 @@
+/* ScummVM - Scumm Interpreter
+ * Copyright (C) 2003 The ScummVM project
+ * Copyright (C) 2003 Robert "LavosSpawn" Goeffringmann
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ *
+ * $Header$
+ *
+ */
+
+#include "skychannel.h"
+#include "sound/fmopl.h"
+
+SkyChannel::SkyChannel(uint8 *pMusicData, uint16 startOfData, FM_OPL *pOpl)
+{
+	_musicData = pMusicData;
+	_opl = pOpl;
+	_channelData.startOfData = startOfData;
+	_channelData.eventDataPtr = startOfData;
+	_channelData.channelActive = 1;
+	_channelData.freqDataSize = 2;
+	_channelData.tremoVibro = 0;
+	_channelData.assignedInstrument = 0xFF;
+	_channelData.channelVolume = 0x7F;
+	_channelData.nextEventTime = getNextEventTime();
+
+	_channelData.adlibChannelNumber = _channelData.lastCommand = _channelData.note =
+		_channelData.adlibReg1 = _channelData.adlibReg2 = _channelData.freqOffset = 0;
+	_channelData.frequency = 0;
+	_channelData.instrumentData = NULL;
+
+	uint16 instrumentDataLoc = (_musicData[0x1206] << 8) | _musicData[0x1205];
+	_instrumentMap = _musicData+instrumentDataLoc;
+	_instruments = (InstrumentStruct*)(_instrumentMap+0x80);
+
+	_frequenceTable = (uint16*)(_musicData+0x7FE);
+	_registerTable = _musicData+0xDFE;
+	_opOutputTable = _musicData+0xE10;
+	_adlibRegMirror = _musicData+0xF5F;
+	_musicVolume = 0x100;
+}
+
+void SkyChannel::updateVolume(uint16 pVolume) {
+
+	_musicVolume = pVolume;
+}
+
+/*	This class uses the same area for the register mirror as the original
+	asm driver did (_musicData[0xF5F..0x105E]), so the cache is indeed shared
+	by all instances of the class.
+*/
+void SkyChannel::setRegister(uint8 regNum, uint8 value) {
+
+	if (_adlibRegMirror[regNum] != value) {
+		OPLWriteReg(_opl,regNum,value);
+		_adlibRegMirror[regNum] = value;
+	}
+}
+
+void SkyChannel::stopNote(void) {
+
+	if (_channelData.note & 0x20) {
+		_channelData.note &= ~0x20;
+		setRegister(0xB0 | _channelData.adlibChannelNumber, _channelData.note);
+	}
+}
+
+int32 SkyChannel::getNextEventTime(void)
+{
+	int32 retV = 0; 
+	uint8 cnt, lVal;
+	for (cnt = 0; cnt < 4; cnt++) {
+		lVal = _musicData[_channelData.eventDataPtr];
+		_channelData.eventDataPtr++;
+		retV = (retV << 7) | (lVal & 0x7F);
+		if (!(lVal & 0x80)) break;
+	}
+	if (lVal & 0x80) { // should never happen
+		return -1;
+	} else return retV;
+
+}
+
+uint8 SkyChannel::process(uint16 aktTime) {
+
+	if (!_channelData.channelActive) {
+		return 0;
+	}
+	
+	uint8 returnVal = 0;
+
+	_channelData.nextEventTime -= aktTime;
+	uint8 opcode;
+	while ((_channelData.nextEventTime < 0) && (_channelData.channelActive)) {
+		opcode = _musicData[_channelData.eventDataPtr];
+		_channelData.eventDataPtr++;
+		if (opcode&0x80) {
+			if (opcode == 0xFF) {
+				// dummy opcode
+			} else if (opcode > 0x9D) {
+                
+			} else if (opcode >= 0x90) {
+				switch (opcode&0xF) {
+					case 0: com90_caseNoteOff(); break;
+					case 1: com90_stopChannel(); break;
+					case 2: com90_setupInstrument(); break;
+					case 3: 
+						returnVal = com90_updateTempo();
+						break;
+					case 5: com90_getFreqOffset(); break;
+					case 6: com90_getChannelVolume(); break;
+					case 7: com90_getTremoVibro(); break;
+					case 8: com90_rewindMusic(); break;
+					case 9: com90_keyOff(); break;
+					case 12: com90_setStartOfData(); break;
+					case 4: //com90_dummy();
+					case 10: //com90_error();
+					case 11: //com90_doLodsb();
+					case 13: //com90_do_two_Lodsb();
+						error("SkyChannel: dummy music routine 0x%02X was called",opcode);
+						_channelData.channelActive = 0;
+						break;
+					default:
+						// these opcodes aren't implemented in original music driver
+						error("SkyChannel: Not existant routine 0x%02X was called",opcode);
+						_channelData.channelActive = 0;
+						break;
+				}
+			} else {
+				// new adlib channel assignment
+				_channelData.adlibChannelNumber = opcode&0xF;
+				_channelData.adlibReg1 = _registerTable[(opcode&0xF)<<1];
+				_channelData.adlibReg2 = _registerTable[((opcode&0xF)<<1)|1];
+			}
+		} else {
+			_channelData.lastCommand = opcode;
+			stopNote();
+			setupInstrument(opcode);
+
+			opcode = _musicData[_channelData.eventDataPtr];
+			_channelData.eventDataPtr++;
+			setupChannelVolume(opcode);
+		}
+		if (_channelData.channelActive)
+			_channelData.nextEventTime += getNextEventTime();
+	}
+	return returnVal;
+}
+
+void SkyChannel::setupInstrument(uint8 opcode) {
+
+	uint16 nextNote;
+	if (_channelData.tremoVibro) {
+		uint8 newInstrument = _instrumentMap[opcode];
+		if (newInstrument != _channelData.assignedInstrument) {
+			_channelData.assignedInstrument = newInstrument;
+			_channelData.instrumentData = _instruments + newInstrument;
+			adlibSetupInstrument();
+		}
+		_channelData.lastCommand = _channelData.instrumentData->bindedEffect;
+		nextNote = getNextNote(_channelData.lastCommand);
+	} else {
+		nextNote = getNextNote(opcode - 0x18 + _channelData.instrumentData->bindedEffect);
+	}
+	_channelData.frequency = nextNote;
+	setRegister(0xA0 | _channelData.adlibChannelNumber, (uint8)nextNote);
+	setRegister(0xB0 | _channelData.adlibChannelNumber, (uint8)((nextNote >> 8) | 0x20));
+	_channelData.note = (uint8)((nextNote >> 8) | 0x20);
+}
+
+void SkyChannel::setupChannelVolume(uint8 volume) {
+
+	uint8 resultOp;
+	uint32 resVol = ((volume + 1) * (_channelData.instrumentData->totOutLev_Op2 + 1)) << 1;
+	resVol &= 0xFFFF;
+	resVol *= (_channelData.channelVolume+1)<<1;
+	resVol >>= 8;
+	resVol *= _musicVolume;
+	resVol >>= 16;
+	resultOp = ((_channelData.instrumentData->scalingLevel << 6) & 0xC0) | _opOutputTable[resVol];
+	setRegister(0x40 | _channelData.adlibReg2, resultOp);
+	if (_channelData.instrumentData->feedBack & 1) {
+		resVol = ((volume + 1) * (_channelData.instrumentData->totOutLev_Op1 + 1)) << 1;
+		resVol &= 0xFFFF;
+		resVol *= (_channelData.channelVolume + 1)<<1;
+		resVol >>= 8;
+		resVol *= (_musicVolume & 0xFF);
+		resVol >>= 16;
+	} else resVol = _channelData.instrumentData->totOutLev_Op1;
+	resultOp = ((_channelData.instrumentData->scalingLevel << 2) & 0xC0) | _opOutputTable[resVol];
+	setRegister(0x40 | _channelData.adlibReg1, resultOp);
+}
+
+void SkyChannel::adlibSetupInstrument(void) {
+
+	setRegister(0x60 | _channelData.adlibReg1, _channelData.instrumentData->ad_Op1);
+	setRegister(0x60 | _channelData.adlibReg2, _channelData.instrumentData->ad_Op2);
+	setRegister(0x80 | _channelData.adlibReg1, _channelData.instrumentData->sr_Op1);
+	setRegister(0x80 | _channelData.adlibReg2, _channelData.instrumentData->sr_Op2);
+	setRegister(0xE0 | _channelData.adlibReg1, _channelData.instrumentData->waveSelect_Op1);
+	setRegister(0xE0 | _channelData.adlibReg2, _channelData.instrumentData->waveSelect_Op2);
+	setRegister(0xC0 | _channelData.adlibChannelNumber, _channelData.instrumentData->feedBack);
+	setRegister(0x20 | _channelData.adlibReg1, _channelData.instrumentData->ampMod_Op1);
+	setRegister(0x20 | _channelData.adlibReg2, _channelData.instrumentData->ampMod_Op2);
+}
+
+#ifdef SCUMM_BIG_ENDIAN
+#define ENDIAN16(x) ((x>>8)|((x&0xFF)<<8))
+#else
+#define ENDIAN16(x) (x)
+#endif
+
+uint16 SkyChannel::getNextNote(uint8 param) {
+
+	int16 freqIndex = ((int16)_channelData.freqOffset)-0x40;
+	if (freqIndex >= 0x3F) freqIndex++;
+	freqIndex *= _channelData.freqDataSize;
+	freqIndex += param<<6;
+	uint16 freqData = ENDIAN16(_frequenceTable[freqIndex%0x300]);
+	if ((freqIndex%0x300 >= 0x1C0) || (freqIndex/0x300 > 0)) {
+		return (((freqIndex/0x300)-1)<<10)+(freqData&0x7FF);
+	} else {
+		// looks like a bug. dunno why. It's what the ASM code says.
+		return (uint16)(((int16)freqData) >> 1);
+	}
+}
+
+//- command 90h routines
+
+void SkyChannel::com90_caseNoteOff(void) {
+
+	if (_musicData[_channelData.eventDataPtr] == _channelData.lastCommand)
+		stopNote();
+	_channelData.eventDataPtr++;
+}
+
+void SkyChannel::com90_stopChannel(void) {
+
+	stopNote();
+	_channelData.channelActive = 0;
+}
+
+void SkyChannel::com90_setupInstrument(void) {
+
+	_channelData.channelVolume = 0x7F;
+	_channelData.freqOffset = 0x40;
+	_channelData.assignedInstrument = _musicData[_channelData.eventDataPtr];
+	_channelData.eventDataPtr++;
+	_channelData.instrumentData = _instruments + _channelData.assignedInstrument;
+	adlibSetupInstrument();
+}
+
+uint8 SkyChannel::com90_updateTempo(void) {
+
+	uint8 retV = _musicData[_channelData.eventDataPtr];
+	_channelData.eventDataPtr++;
+	return retV;
+}
+
+void SkyChannel::com90_getFreqOffset(void) {
+
+	_channelData.freqOffset = _musicData[_channelData.eventDataPtr];
+	_channelData.eventDataPtr++;
+	if (_channelData.note) {
+		uint16 nextNote = getNextNote(
+			_channelData.lastCommand - 0x18 + _channelData.instrumentData->bindedEffect);
+		setRegister(0xA0|_channelData.adlibChannelNumber, (uint8)nextNote);
+		setRegister(0xB0|_channelData.adlibChannelNumber, (uint8)((nextNote>>8)|0x20));
+		_channelData.note = (uint8)(nextNote>>8)|0x20;
+	}
+}
+
+void SkyChannel::com90_getChannelVolume(void) {
+
+	_channelData.channelVolume = _musicData[_channelData.eventDataPtr];
+	_channelData.eventDataPtr++;
+}
+
+void SkyChannel::com90_getTremoVibro(void) {
+
+	_channelData.tremoVibro = _musicData[_channelData.eventDataPtr];
+	_channelData.eventDataPtr++;
+}
+
+void SkyChannel::com90_rewindMusic(void) {
+
+	_channelData.eventDataPtr = _channelData.startOfData;
+}
+
+void SkyChannel::com90_keyOff(void) {
+
+	stopNote();
+}
+
+void SkyChannel::com90_setStartOfData(void) {
+
+	_channelData.startOfData = _channelData.eventDataPtr;
+}
diff --git a/sky/skychannel.h b/sky/skychannel.h
new file mode 100644
index 0000000000..e4134652ea
--- /dev/null
+++ b/sky/skychannel.h
@@ -0,0 +1,102 @@
+/* ScummVM - Scumm Interpreter
+ * Copyright (C) 2003 The ScummVM project
+ * Copyright (C) 2003 Robert "LavosSpawn" Goeffringmann
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ *
+ * $Header$
+ *
+ */
+
+#ifndef __SkyChannel__
+#define __SkyChannel__
+
+#include "stdafx.h"
+#include "sound/fmopl.h"
+#include "common/engine.h"
+
+typedef struct {
+	uint8 ad_Op1, ad_Op2;
+	uint8 sr_Op1, sr_Op2;
+	uint8 ampMod_Op1, ampMod_Op2;
+	uint8 waveSelect_Op1, waveSelect_Op2;
+	uint8 bindedEffect;
+	uint8 feedBack;
+	uint8 totOutLev_Op1, totOutLev_Op2;
+	uint8 scalingLevel;
+	uint8 pad1, pad2, pad3;
+} InstrumentStruct;
+
+typedef struct {
+	uint16 eventDataPtr;
+	int32 nextEventTime;
+	uint16 startOfData;
+	uint8 adlibChannelNumber;
+	uint8 lastCommand;
+	uint8 channelActive;
+	uint8 note;
+	uint8 adlibReg1, adlibReg2;
+	InstrumentStruct *instrumentData;
+	uint8 assignedInstrument;
+	uint8 channelVolume;
+	uint8 padding; // field_12 / not used by original driver
+	uint8 tremoVibro;
+	uint8 freqDataSize;
+	uint8 freqOffset;
+	uint16 frequency;
+} ChannelType;
+
+class SkyChannel {
+public:
+	SkyChannel(uint8 *pMusicData, uint16 startOfData, FM_OPL *pOpl);
+	void stopNote(void);
+	uint8 process(uint16 aktTime);
+	void updateVolume(uint16 pVolume);
+private:
+	uint8 *_musicData;
+	uint16 _musicVolume;
+	FM_OPL *_opl;
+	ChannelType _channelData;
+	//-
+	InstrumentStruct *_instruments;
+	uint16 *_frequenceTable;
+	uint8 *_instrumentMap;
+    uint8 *_registerTable, *_opOutputTable;
+	uint8 *_adlibRegMirror;
+	//-                          normal subs
+	void setRegister(uint8 regNum, uint8 value);
+	int32 getNextEventTime(void);
+	uint16 getNextNote(uint8 param);
+	void adlibSetupInstrument(void);
+	void setupInstrument(uint8 opcode);
+	void setupChannelVolume(uint8 volume);
+    //-                          Streamfunctions from Command90hTable
+	void com90_caseNoteOff(void);       // 0
+	void com90_stopChannel(void);       // 1
+	void com90_setupInstrument(void);   // 2
+	uint8 com90_updateTempo(void);       // 3
+	//void com90_dummy(void);           // 4
+	void com90_getFreqOffset(void);     // 5
+	void com90_getChannelVolume(void);  // 6
+	void com90_getTremoVibro(void);     // 7
+	void com90_rewindMusic(void);       // 8
+	void com90_keyOff(void);            // 9
+	//void com90_error(void);           // 10
+	//void com90_doLodsb(void);         // 11
+	void com90_setStartOfData(void);    // 12
+	//void com90_do_two_Lodsb(void);    // 13
+};
+
+#endif //__SkyChannel__
diff --git a/sky/skymusic.cpp b/sky/skymusic.cpp
new file mode 100644
index 0000000000..b546a08464
--- /dev/null
+++ b/sky/skymusic.cpp
@@ -0,0 +1,241 @@
+/* ScummVM - Scumm Interpreter
+ * Copyright (C) 2003 The ScummVM project
+ * Copyright (C) 2003 Robert "LavosSpawn" Goeffringmann
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ *
+ * $Header$
+ *
+ */
+
+#include "skymusic.h"
+
+void SkyMusic::passMixerFunc(void *param, int16 *buf, uint len) {
+
+	((SkyMusic*)param)->premixerCall(buf, len);
+}
+
+void SkyMusic::premixerCall(int16 *buf, uint len) {
+
+	if (_musicData == NULL) {
+		// no music loaded
+		memset(buf, 0, len * sizeof(int16));
+		return;
+	} else if ((_currentMusic == 0) || (_numberOfChannels == 0)) {
+		// music loaded but not played as of yet
+		memset(buf, 0, len * sizeof(int16));
+		// poll anyways as pollMusic() can activate the music
+		pollMusic();
+		_nextMusicPoll = _sampleRate/50;
+		return;
+	}
+	uint32 render;
+	while (len) {
+		render = (len > _nextMusicPoll) ? (_nextMusicPoll) : (len);
+		len -= render;
+		_nextMusicPoll -= render;
+		YM3812UpdateOne(_opl, buf, render);
+		buf += render;
+		if (_nextMusicPoll == 0) {
+			pollMusic();
+			_nextMusicPoll = _sampleRate/50;
+		}
+	}
+}
+
+SkyMusic::SkyMusic(SoundMixer *mixer, SkyDisk *pSkyDisk) {
+
+	_musicData = NULL;
+	_allowedCommands = 0;
+	_mixer = mixer;
+	_sampleRate = g_system->property(OSystem::PROP_GET_SAMPLE_RATE, 0);
+	int env_bits = g_system->property(OSystem::PROP_GET_FMOPL_ENV_BITS, NULL);
+	int eg_ent = g_system->property(OSystem::PROP_GET_FMOPL_EG_ENT, NULL);
+	OPLBuildTables((env_bits ? env_bits : FMOPL_ENV_BITS_HQ), (eg_ent ? eg_ent : FMOPL_EG_ENT_HQ));
+	_opl = OPLCreate(OPL_TYPE_YM3812, 3579545, _sampleRate);
+	_mixer->setupPremix(this, passMixerFunc);
+	_skyDisk = pSkyDisk;
+}
+
+SkyMusic::~SkyMusic(void)
+{
+	if (_currentMusic) stopMusic();
+	_mixer->setupPremix(NULL, NULL);
+	if (_musicData) free(_musicData);
+	OPLDestroy(_opl);
+}
+
+void SkyMusic::loadSectionMusic(uint8 pSection)
+{
+	if (_currentMusic) stopMusic();
+	if (_musicData) free(_musicData);
+	_musicData = _skyDisk->loadFile(MUSIC_BASE_FILE + FILES_PER_SECTION*pSection,NULL);
+	_allowedCommands = 0;
+	_musicTempo0 = 0x78; // init constants taken from idb file, area ~0x1060
+	_musicTempo1 = 0xC0;
+	_musicVolume = 0x100;
+	_numberOfChannels = _currentMusic = 0;
+	_musicDataLoc = (_musicData[0x1202]<<8)|_musicData[0x1201];
+	_initSequence = _musicData+0xE91;
+	_onNextPoll.doReInit = false;
+	_onNextPoll.doStopMusic = false;
+	_onNextPoll.musicToProcess = 0;
+	_tempo = _aktTime = 0x10001;
+	_nextMusicPoll = 0;
+	startAdlibDriver();
+}
+
+/*void SkyMusic::loadData(uint8 *pMusicData)
+{
+	if (_currentMusic) stopMusic();
+	if (_musicData) free(_musicData);
+	_musicData = pMusicData;
+	_allowedCommands = 0;
+	_musicTempo0 = 0x78; // init constants taken from idb file, area ~0x1060
+	_musicTempo1 = 0xC0;
+	_musicVolume = 0x100;
+	_numberOfChannels = _currentMusic = 0;
+	_musicDataLoc = (_musicData[0x1202]<<8)|_musicData[0x1201];
+	_initSequence = _musicData+0xE91;
+	_onNextPoll.doReInit = false;
+	_onNextPoll.doStopMusic = false;
+	_onNextPoll.musicToProcess = 0;
+	_tempo = _aktTime = 0x10001;
+	_nextMusicPoll = 0;
+}*/
+
+void SkyMusic::musicCommand(uint16 command)
+{
+	if (_musicData == NULL) {
+		debug(1,"Got music command but driver is not yet loaded.\n");
+		return ;
+	}
+	if ((command >> 8) > _allowedCommands) {
+		debug(1,"got musicCommand %d while expecting <= %d\n", command >> 8, _allowedCommands);
+		return ;
+	}
+	switch(command >> 8) {
+		case 0: 
+			//startAdlibDriver(); break;
+			debug(1,"SkyMusic: got call to startAdlibDriver(). Not necessary in this implementation.\n");
+			break;
+		case 1: 
+			//StopDriver(command&0xFF); break;
+			debug(1,"SkyMusic: got call to stopDriver(). Not necessary in this implementation.\n");
+			break;
+		case 2:
+			debug(1,"SkyMusic: got call to SetTempo(). Tempo is fixed in this implementation.\n");
+			break;
+		case 3: 
+			debug(1,"SkyMusic: ignored direct call to driverPoll().\n");
+			break;
+		case 4: 
+			startMusic(command&0xFF);
+			break;
+		case 6:
+			reinitFM();
+			break;
+		case 7:
+			stopMusic();
+			break;
+		case 13: 
+			setFMVolume(command&0xFF); 
+			break;
+		default: 
+			debug(1,"musicCommand %d ignored.\n",command>>8);
+	}
+}
+
+void SkyMusic::setFMVolume(uint16 param)
+{
+	_musicVolume = param;
+	for (uint8 cnt = 0; cnt < _numberOfChannels; cnt++)
+		_channels[cnt]->updateVolume(_musicVolume);
+}
+
+void SkyMusic::startAdlibDriver(void)
+{
+	uint16 cnt = 0;
+	while (_initSequence[cnt] || _initSequence[cnt+1]) {
+		OPLWriteReg(_opl, _initSequence[cnt], _initSequence[cnt+1]);
+		cnt += 2;
+	}
+	_allowedCommands = 0xD;
+}
+
+void SkyMusic::stopMusic(void)
+{
+	for (uint8 cnt = 0; cnt < _numberOfChannels; cnt++) {
+		_channels[cnt]->stopNote();
+		delete _channels[cnt];
+	}
+	_numberOfChannels = 0;
+}
+
+void SkyMusic::updateTempo(void)
+{
+	uint16 tempoMul = _musicTempo0*_musicTempo1;
+	uint16 divisor = 0x4446390/23864;
+	_tempo = (tempoMul / divisor)<<16;
+	_tempo |= (((tempoMul%divisor)<<16) | (tempoMul/divisor)) / divisor;
+}
+
+void SkyMusic::loadNewMusic(void)
+{
+	uint16 musicPos;
+	if (_onNextPoll.musicToProcess > _musicData[_musicDataLoc]) {
+		error("Music %d requested but doesn't exist in file.\n", _onNextPoll.musicToProcess);
+		return;
+	}
+	if (_currentMusic != 0) stopMusic();
+
+	_currentMusic = _onNextPoll.musicToProcess;
+	_onNextPoll.musicToProcess = 0;
+
+	if (_currentMusic != 0) {
+		musicPos = (_musicData[_musicDataLoc+2]<<8) | _musicData[_musicDataLoc+1];
+		musicPos += _musicDataLoc+((_currentMusic-1)<<1);
+		musicPos = ((_musicData[musicPos+1]<<8) | _musicData[musicPos]) + _musicDataLoc;
+
+		_musicTempo1 = _musicData[musicPos+1];
+		_musicTempo0 = _musicData[musicPos];
+		_numberOfChannels = _musicData[musicPos+2];
+		musicPos += 3;
+
+		for (uint8 cnt = 0; cnt < _numberOfChannels; cnt++) {
+			uint16 chDataStart = ((_musicData[musicPos+1]<<8) | _musicData[musicPos]) + _musicDataLoc;
+			_channels[cnt] = new SkyChannel(_musicData, chDataStart, _opl);
+			musicPos += 2;		
+		}
+		updateTempo();
+	}
+}
+
+void SkyMusic::pollMusic(void)
+{
+	uint8 newTempo;
+	if (_onNextPoll.doReInit) startAdlibDriver();
+	if (_onNextPoll.doStopMusic) stopMusic();
+	if (_onNextPoll.musicToProcess) loadNewMusic();
+	_aktTime += _tempo;
+	for (uint8 cnt = 0; cnt < _numberOfChannels; cnt++) {
+		newTempo = _channels[cnt]->process((uint16)(_aktTime >> 16));
+		if (newTempo) {
+			_musicTempo1 = newTempo;
+			updateTempo();
+		}
+	}
+	_aktTime &= 0xFFFF;
+}
diff --git a/sky/skymusic.h b/sky/skymusic.h
new file mode 100644
index 0000000000..d81b7f65ba
--- /dev/null
+++ b/sky/skymusic.h
@@ -0,0 +1,84 @@
+/* ScummVM - Scumm Interpreter
+ * Copyright (C) 2003 The ScummVM project
+ * Copyright (C) 2003 Robert "LavosSpawn" Goeffringmann
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ *
+ * $Header$
+ *
+ */
+
+
+#ifndef __SkyMusicDriver__
+#define __SkyMusicDriver__
+
+#include "stdafx.h"
+#include "sound/fmopl.h"
+#include "sound/mixer.h"
+#include "common/engine.h"
+#include "skychannel.h"
+#include "disk.h"
+
+#define MUSIC_BASE_FILE 60202 // usually 60200 ( + 0 for Roland and +2 for Adlib)
+#define FILES_PER_SECTION 4
+
+typedef struct {
+	bool doReInit, doStopMusic;
+	uint8 musicToProcess;
+} Actions;
+
+class SkyMusic {
+public:
+	SkyMusic(SoundMixer *mixer, SkyDisk *pSkyDisk);
+	~SkyMusic(void);
+	//void loadData(uint8 *pMusicData);
+	void loadSectionMusic(uint8 pSection);
+	void musicCommand(uint16 command);
+	void startMusic(uint16 param) { _onNextPoll.musicToProcess = param & 0xF; }; // 4
+	
+private:
+	SoundMixer *_mixer;
+	SkyDisk *_skyDisk;
+	FM_OPL *_opl;
+	uint8 *_musicData;
+	uint8 *_initSequence;
+	uint8 _allowedCommands;
+	uint16 _musicDataLoc;
+	SkyChannel *_channels[10];
+
+	uint16 _musicVolume, _numberOfChannels;
+	uint8 _currentMusic;
+	uint8 _musicTempo0; // can be changed by music stream
+	uint8 _musicTempo1; // given once per music
+	uint32 _tempo;      // calculated from musicTempo0 and musicTempo1
+	uint32 _aktTime;
+	uint32 _sampleRate, _nextMusicPoll;
+	Actions _onNextPoll;
+	
+	void premixerCall(int16 *buf, uint len);
+	static void passMixerFunc(void *param, int16 *buf, uint len);
+	void updateTempo(void);
+	void loadNewMusic(void);
+	//-                           functions from CommandTable @0x90 (the main interface)
+	void startAdlibDriver(void);                                                 // 0
+	void StopDriver(void);                                                       // 1
+	void setTempo(uint16 newTempo);                                              // 2
+	void pollMusic();                                                            // 3
+	void reinitFM(void) { _onNextPoll.doReInit = true; };                        // 6
+	void stopMusic();                                                            // 7
+	void setFMVolume(uint16 param);                                              // 13
+};
+
+#endif //__SkyMusicDriver__