SOUND: Move CMS emulator to sound/softsynth.

svn-id: r52778

4 files changed, 438 insertions, 383 deletions

diff --git a/engines/scumm/player_v2cms.cpp b/engines/scumm/player_v2cms.cpp
index e3e7bc1901..ba60a31061 100644
--- a/engines/scumm/player_v2cms.cpp
+++ b/engines/scumm/player_v2cms.cpp
@@ -28,6 +28,7 @@
 #include "scumm/scumm.h"
 #include "sound/mididrv.h"
 #include "sound/mixer.h"
+#include "sound/softsynth/cms.h"
 
 namespace Scumm {
 
@@ -40,395 +41,13 @@ namespace Scumm {
 #define FB_WNOISE 0x12000       /* feedback for white noise */
 #define FB_PNOISE 0x08000       /* feedback for periodic noise */
 
-// CMS/Gameblaster Emulation taken from DosBox
-
-#define LEFT	0x00
-#define RIGHT	0x01
-#define MAX_OUTPUT 0x7fff
-#define MIN_OUTPUT -0x8000
-//#define CMS_BUFFER_SIZE 128
-#define CMS_RATE 22050
-
 #define PROCESS_ATTACK 1
 #define PROCESS_RELEASE 2
 #define PROCESS_SUSTAIN 3
 #define PROCESS_DECAY 4
 #define PROCESS_VIBRATO 5
 
-/* this structure defines a channel */
-struct saa1099_channel {
-	int frequency;				/* frequency (0x00..0xff) */
-	int freq_enable;			/* frequency enable */
-	int noise_enable;			/* noise enable */
-	int octave;				/* octave (0x00..0x07) */
-	int amplitude[2];			/* amplitude (0x00..0x0f) */
-	int envelope[2];			/* envelope (0x00..0x0f or 0x10 == off) */
-
-	/* vars to simulate the square wave */
-	double counter;
-	double freq;
-	int level;
-};
-
-/* this structure defines a noise channel */
-struct saa1099_noise {
-	/* vars to simulate the noise generator output */
-	double counter;
-	double freq;
-	int level;				/* noise polynomal shifter */
-};
-
-/* this structure defines a SAA1099 chip */
-struct SAA1099 {
-	int stream;				/* our stream */
-	int noise_params[2];			/* noise generators parameters */
-	int env_enable[2];			/* envelope generators enable */
-	int env_reverse_right[2];		/* envelope reversed for right channel */
-	int env_mode[2];			/* envelope generators mode */
-	int env_bits[2];			/* non zero = 3 bits resolution */
-	int env_clock[2];			/* envelope clock mode (non-zero external) */
-	int env_step[2];			/* current envelope step */
-	int all_ch_enable;			/* all channels enable */
-	int sync_state;				/* sync all channels */
-	int selected_reg;			/* selected register */
-	struct saa1099_channel channels[6];	/* channels */
-	struct saa1099_noise noise[2];		/* noise generators */
-};
-
-static byte envelope[8][64] = {
-	/* zero amplitude */
-	{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
-	/* maximum amplitude */
-	{15,15,15,15,15,15,15,15,15,15,15,15,15,15,15,15,
-	 15,15,15,15,15,15,15,15,15,15,15,15,15,15,15,15,
-	 15,15,15,15,15,15,15,15,15,15,15,15,15,15,15,15,
-	 15,15,15,15,15,15,15,15,15,15,15,15,15,15,15,15, },
-	/* single decay */
-	{15,14,13,12,11,10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0,
-	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
-	/* repetitive decay */
-	{15,14,13,12,11,10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0,
-	 15,14,13,12,11,10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0,
-	 15,14,13,12,11,10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0,
-	 15,14,13,12,11,10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0 },
-	/* single triangular */
-	{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,10,11,12,13,14,15,
-	 15,14,13,12,11,10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0,
-	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
-	/* repetitive triangular */
-	{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,10,11,12,13,14,15,
-	 15,14,13,12,11,10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0,
-	  0, 1, 2, 3, 4, 5, 6, 7, 8, 9,10,11,12,13,14,15,
-	 15,14,13,12,11,10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0 },
-	/* single attack */
-	{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,10,11,12,13,14,15,
-	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
-	/* repetitive attack */
-	{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,10,11,12,13,14,15,
-	  0, 1, 2, 3, 4, 5, 6, 7, 8, 9,10,11,12,13,14,15,
-	  0, 1, 2, 3, 4, 5, 6, 7, 8, 9,10,11,12,13,14,15,
-	  0, 1, 2, 3, 4, 5, 6, 7, 8, 9,10,11,12,13,14,15 }
-};
-
-static int amplitude_lookup[16] = {
-	 0*32767/16,  1*32767/16,  2*32767/16,	3*32767/16,
-	 4*32767/16,  5*32767/16,  6*32767/16,	7*32767/16,
-	 8*32767/16,  9*32767/16, 10*32767/16, 11*32767/16,
-	12*32767/16, 13*32767/16, 14*32767/16, 15*32767/16
-};
-
-class CMSEmulator {
-public:
-	CMSEmulator(uint32 sampleRate) {
-		_sampleRate = sampleRate;
-		memset(_saa1099, 0, sizeof(SAA1099)*2);
-	}
-
-	~CMSEmulator() { }
-
-	void portWrite(int port, int val);
-	void readBuffer(int16 *buffer, const int numSamples);
-private:
-	uint32 _sampleRate;
-
-	SAA1099 _saa1099[2];
-
-	void envelope(int chip, int ch);
-	void update(int chip, int16 *buffer, int length);
-	void portWriteIntern(int chip, int offset, int data);
-};
-
-void CMSEmulator::portWrite(int port, int val) {
-	switch (port) {
-		case 0x220:
-			portWriteIntern(0, 1, val);
-			break;
-
-		case 0x221:
-			_saa1099[0].selected_reg = val & 0x1f;
-			if (_saa1099[0].selected_reg == 0x18 || _saa1099[0].selected_reg == 0x19) {
-				/* clock the envelope channels */
-				if (_saa1099[0].env_clock[0]) envelope(0, 0);
-				if (_saa1099[0].env_clock[1]) envelope(0, 1);
-			}
-			break;
-
-		case 0x222:
-			portWriteIntern(1, 1, val);
-			break;
-
-		case 0x223:
-			_saa1099[1].selected_reg = val & 0x1f;
-			if (_saa1099[1].selected_reg == 0x18 || _saa1099[1].selected_reg == 0x19) {
-				/* clock the envelope channels */
-				if (_saa1099[1].env_clock[0]) envelope(1, 0);
-				if (_saa1099[1].env_clock[1]) envelope(1, 1);
-			}
-			break;
-
-		default:
-			warning("CMSEmulator got port: 0x%X", port);
-			break;
-	}
-}
-
-void CMSEmulator::readBuffer(int16 *buffer, const int numSamples) {
-	update(0, &buffer[0], numSamples);
-	update(1, &buffer[0], numSamples);
-}
-
-void CMSEmulator::envelope(int chip, int ch) {
-	SAA1099 *saa = &_saa1099[chip];
-	if (saa->env_enable[ch]) {
-		int step, mode, mask;
-		mode = saa->env_mode[ch];
-		/* step from 0..63 and then loop in steps 32..63 */
-		step = saa->env_step[ch] = ((saa->env_step[ch] + 1) & 0x3f) | (saa->env_step[ch] & 0x20);
-
-		mask = 15;
-		if (saa->env_bits[ch])
-			mask &= ~1; 	/* 3 bit resolution, mask LSB */
-
-		saa->channels[ch*3+0].envelope[ LEFT] =
-		saa->channels[ch*3+1].envelope[ LEFT] =
-		saa->channels[ch*3+2].envelope[ LEFT] = Scumm::envelope[mode][step] & mask;
-		if (saa->env_reverse_right[ch] & 0x01) {
-			saa->channels[ch*3+0].envelope[RIGHT] =
-			saa->channels[ch*3+1].envelope[RIGHT] =
-			saa->channels[ch*3+2].envelope[RIGHT] = (15 - Scumm::envelope[mode][step]) & mask;
-		} else {
-			saa->channels[ch*3+0].envelope[RIGHT] =
-			saa->channels[ch*3+1].envelope[RIGHT] =
-			saa->channels[ch*3+2].envelope[RIGHT] = Scumm::envelope[mode][step] & mask;
-		}
-	} else {
-		/* envelope mode off, set all envelope factors to 16 */
-		saa->channels[ch*3+0].envelope[ LEFT] =
-		saa->channels[ch*3+1].envelope[ LEFT] =
-		saa->channels[ch*3+2].envelope[ LEFT] =
-		saa->channels[ch*3+0].envelope[RIGHT] =
-		saa->channels[ch*3+1].envelope[RIGHT] =
-		saa->channels[ch*3+2].envelope[RIGHT] = 16;
-	}
-}
-
-void CMSEmulator::update(int chip, int16 *buffer, int length) {
-	struct SAA1099 *saa = &_saa1099[chip];
-	int j, ch;
-
-	/* if the channels are disabled we're done */
-	if (!saa->all_ch_enable) {
-		/* init output data */
-		if (chip == 0) {
-			memset(buffer, 0, sizeof(int16)*length*2);
-		}
-		return;
-	}
-
-	if (chip == 0) {
-		memset(buffer, 0, sizeof(int16)*length*2);
-	}
-
-	for (ch = 0; ch < 2; ch++) {
-		switch (saa->noise_params[ch]) {
-			case 0: saa->noise[ch].freq = 31250.0 * 2; break;
-			case 1: saa->noise[ch].freq = 15625.0 * 2; break;
-			case 2: saa->noise[ch].freq =  7812.5 * 2; break;
-			case 3: saa->noise[ch].freq = saa->channels[ch * 3].freq; break;
-		}
-	}
-
-	/* fill all data needed */
-	for (j = 0; j < length; ++j) {
-		int output_l = 0, output_r = 0;
-
-		/* for each channel */
-		for (ch = 0; ch < 6; ch++) {
-			if (saa->channels[ch].freq == 0.0)
-				saa->channels[ch].freq = (double)((2 * 15625) << saa->channels[ch].octave) /
-				(511.0 - (double)saa->channels[ch].frequency);
-
-			/* check the actual position in the square wave */
-			saa->channels[ch].counter -= saa->channels[ch].freq;
-			while (saa->channels[ch].counter < 0) {
-				/* calculate new frequency now after the half wave is updated */
-				saa->channels[ch].freq = (double)((2 * 15625) << saa->channels[ch].octave) /
-					(511.0 - (double)saa->channels[ch].frequency);
-
-				saa->channels[ch].counter += _sampleRate;
-				saa->channels[ch].level ^= 1;
-
-				/* eventually clock the envelope counters */
-				if (ch == 1 && saa->env_clock[0] == 0)
-					envelope(chip, 0);
-				if (ch == 4 && saa->env_clock[1] == 0)
-					envelope(chip, 1);
-			}
-
-			/* if the noise is enabled */
-			if (saa->channels[ch].noise_enable) {
-				/* if the noise level is high (noise 0: chan 0-2, noise 1: chan 3-5) */
-				if (saa->noise[ch/3].level & 1) {
-					/* subtract to avoid overflows, also use only half amplitude */
-					output_l -= saa->channels[ch].amplitude[ LEFT] * saa->channels[ch].envelope[ LEFT] / 16 / 2;
-					output_r -= saa->channels[ch].amplitude[RIGHT] * saa->channels[ch].envelope[RIGHT] / 16 / 2;
-				}
-			}
-
-			/* if the square wave is enabled */
-			if (saa->channels[ch].freq_enable) {
-				/* if the channel level is high */
-				if (saa->channels[ch].level & 1) {
-					output_l += saa->channels[ch].amplitude[ LEFT] * saa->channels[ch].envelope[ LEFT] / 16;
-					output_r += saa->channels[ch].amplitude[RIGHT] * saa->channels[ch].envelope[RIGHT] / 16;
-				}
-			}
-		}
-
-		for (ch = 0; ch < 2; ch++) {
-			/* check the actual position in noise generator */
-			saa->noise[ch].counter -= saa->noise[ch].freq;
-			while (saa->noise[ch].counter < 0) {
-				saa->noise[ch].counter += _sampleRate;
-				if (((saa->noise[ch].level & 0x4000) == 0) == ((saa->noise[ch].level & 0x0040) == 0) )
-					saa->noise[ch].level = (saa->noise[ch].level << 1) | 1;
-				else
-					saa->noise[ch].level <<= 1;
-			}
-		}
-		/* write sound data to the buffer */
-		buffer[j*2] += output_l / 6;
-		buffer[j*2+1] += output_r / 6;
-	}
-}
-
-void CMSEmulator::portWriteIntern(int chip, int offset, int data) {
-	SAA1099 *saa = &_saa1099[chip];
-	int reg = saa->selected_reg;
-	int ch;
-
-	switch (reg) {
-		/* channel i amplitude */
-		case 0x00:
-		case 0x01:
-		case 0x02:
-		case 0x03:
-		case 0x04:
-		case 0x05:
-			ch = reg & 7;
-			saa->channels[ch].amplitude[LEFT] = amplitude_lookup[data & 0x0f];
-			saa->channels[ch].amplitude[RIGHT] = amplitude_lookup[(data >> 4) & 0x0f];
-			break;
-
-		/* channel i frequency */
-		case 0x08:
-		case 0x09:
-		case 0x0a:
-		case 0x0b:
-		case 0x0c:
-		case 0x0d:
-			ch = reg & 7;
-			saa->channels[ch].frequency = data & 0xff;
-			break;
-
-		/* channel i octave */
-		case 0x10:
-		case 0x11:
-		case 0x12:
-			ch = (reg - 0x10) << 1;
-			saa->channels[ch + 0].octave = data & 0x07;
-			saa->channels[ch + 1].octave = (data >> 4) & 0x07;
-			break;
-
-		/* channel i frequency enable */
-		case 0x14:
-			saa->channels[0].freq_enable = data & 0x01;
-			saa->channels[1].freq_enable = data & 0x02;
-			saa->channels[2].freq_enable = data & 0x04;
-			saa->channels[3].freq_enable = data & 0x08;
-			saa->channels[4].freq_enable = data & 0x10;
-			saa->channels[5].freq_enable = data & 0x20;
-			break;
-
-		/* channel i noise enable */
-		case 0x15:
-			saa->channels[0].noise_enable = data & 0x01;
-			saa->channels[1].noise_enable = data & 0x02;
-			saa->channels[2].noise_enable = data & 0x04;
-			saa->channels[3].noise_enable = data & 0x08;
-			saa->channels[4].noise_enable = data & 0x10;
-			saa->channels[5].noise_enable = data & 0x20;
-			break;
-
-		/* noise generators parameters */
-		case 0x16:
-			saa->noise_params[0] = data & 0x03;
-			saa->noise_params[1] = (data >> 4) & 0x03;
-			break;
-
-		/* envelope generators parameters */
-		case 0x18:
-		case 0x19:
-			ch = reg - 0x18;
-			saa->env_reverse_right[ch] = data & 0x01;
-			saa->env_mode[ch] = (data >> 1) & 0x07;
-			saa->env_bits[ch] = data & 0x10;
-			saa->env_clock[ch] = data & 0x20;
-			saa->env_enable[ch] = data & 0x80;
-			/* reset the envelope */
-			saa->env_step[ch] = 0;
-			break;
-
-		/* channels enable & reset generators */
-		case 0x1c:
-			saa->all_ch_enable = data & 0x01;
-			saa->sync_state = data & 0x02;
-			if (data & 0x02) {
-				int i;
-				/* Synch & Reset generators */
-				for (i = 0; i < 6; i++) {
-					saa->channels[i].level = 0;
-					saa->channels[i].counter = 0.0;
-				}
-			}
-			break;
-
-		default:	/* Error! */
-			error("CMS Unkown write to reg %x with %x",reg, data);
-	}
-}
-
-#pragma mark -
-#pragma mark - Player_V2CMS
-#pragma mark -
+#define CMS_RATE 22050
 
 const uint8 note_lengths[] = {
 	0,
diff --git a/sound/module.mk b/sound/module.mk
index 70bffb13d2..7992d3822b 100644
--- a/sound/module.mk
+++ b/sound/module.mk
@@ -33,6 +33,7 @@ MODULE_OBJS := \
 	mods/soundfx.o \
 	mods/tfmx.o \
 	softsynth/adlib.o \
+	softsynth/cms.o \
 	softsynth/opl/dbopl.o \
 	softsynth/opl/dosbox.o \
 	softsynth/opl/mame.o \
diff --git a/sound/softsynth/cms.cpp b/sound/softsynth/cms.cpp
new file mode 100644
index 0000000000..974db0dea8
--- /dev/null
+++ b/sound/softsynth/cms.cpp
@@ -0,0 +1,343 @@
+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * $URL$
+ * $Id$
+ */
+
+#include "sound/softsynth/cms.h"
+
+#include "common/textconsole.h"
+
+// CMS/Gameblaster Emulation taken from DosBox
+
+#define LEFT	0x00
+#define RIGHT	0x01
+
+static byte envelope[8][64] = {
+	/* zero amplitude */
+	{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
+	/* maximum amplitude */
+	{15,15,15,15,15,15,15,15,15,15,15,15,15,15,15,15,
+	 15,15,15,15,15,15,15,15,15,15,15,15,15,15,15,15,
+	 15,15,15,15,15,15,15,15,15,15,15,15,15,15,15,15,
+	 15,15,15,15,15,15,15,15,15,15,15,15,15,15,15,15, },
+	/* single decay */
+	{15,14,13,12,11,10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0,
+	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
+	/* repetitive decay */
+	{15,14,13,12,11,10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0,
+	 15,14,13,12,11,10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0,
+	 15,14,13,12,11,10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0,
+	 15,14,13,12,11,10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0 },
+	/* single triangular */
+	{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,10,11,12,13,14,15,
+	 15,14,13,12,11,10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0,
+	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
+	/* repetitive triangular */
+	{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,10,11,12,13,14,15,
+	 15,14,13,12,11,10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0,
+	  0, 1, 2, 3, 4, 5, 6, 7, 8, 9,10,11,12,13,14,15,
+	 15,14,13,12,11,10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0 },
+	/* single attack */
+	{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,10,11,12,13,14,15,
+	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
+	/* repetitive attack */
+	{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,10,11,12,13,14,15,
+	  0, 1, 2, 3, 4, 5, 6, 7, 8, 9,10,11,12,13,14,15,
+	  0, 1, 2, 3, 4, 5, 6, 7, 8, 9,10,11,12,13,14,15,
+	  0, 1, 2, 3, 4, 5, 6, 7, 8, 9,10,11,12,13,14,15 }
+};
+
+static int amplitude_lookup[16] = {
+	 0*32767/16,  1*32767/16,  2*32767/16,	3*32767/16,
+	 4*32767/16,  5*32767/16,  6*32767/16,	7*32767/16,
+	 8*32767/16,  9*32767/16, 10*32767/16, 11*32767/16,
+	12*32767/16, 13*32767/16, 14*32767/16, 15*32767/16
+};
+
+void CMSEmulator::portWrite(int port, int val) {
+	switch (port) {
+		case 0x220:
+			portWriteIntern(0, 1, val);
+			break;
+
+		case 0x221:
+			_saa1099[0].selected_reg = val & 0x1f;
+			if (_saa1099[0].selected_reg == 0x18 || _saa1099[0].selected_reg == 0x19) {
+				/* clock the envelope channels */
+				if (_saa1099[0].env_clock[0]) envelope(0, 0);
+				if (_saa1099[0].env_clock[1]) envelope(0, 1);
+			}
+			break;
+
+		case 0x222:
+			portWriteIntern(1, 1, val);
+			break;
+
+		case 0x223:
+			_saa1099[1].selected_reg = val & 0x1f;
+			if (_saa1099[1].selected_reg == 0x18 || _saa1099[1].selected_reg == 0x19) {
+				/* clock the envelope channels */
+				if (_saa1099[1].env_clock[0]) envelope(1, 0);
+				if (_saa1099[1].env_clock[1]) envelope(1, 1);
+			}
+			break;
+
+		default:
+			warning("CMSEmulator got port: 0x%X", port);
+			break;
+	}
+}
+
+void CMSEmulator::readBuffer(int16 *buffer, const int numSamples) {
+	update(0, &buffer[0], numSamples);
+	update(1, &buffer[0], numSamples);
+}
+
+void CMSEmulator::envelope(int chip, int ch) {
+	SAA1099 *saa = &_saa1099[chip];
+	if (saa->env_enable[ch]) {
+		int step, mode, mask;
+		mode = saa->env_mode[ch];
+		/* step from 0..63 and then loop in steps 32..63 */
+		step = saa->env_step[ch] = ((saa->env_step[ch] + 1) & 0x3f) | (saa->env_step[ch] & 0x20);
+
+		mask = 15;
+		if (saa->env_bits[ch])
+			mask &= ~1; 	/* 3 bit resolution, mask LSB */
+
+		saa->channels[ch*3+0].envelope[ LEFT] =
+		saa->channels[ch*3+1].envelope[ LEFT] =
+		saa->channels[ch*3+2].envelope[ LEFT] = ::envelope[mode][step] & mask;
+		if (saa->env_reverse_right[ch] & 0x01) {
+			saa->channels[ch*3+0].envelope[RIGHT] =
+			saa->channels[ch*3+1].envelope[RIGHT] =
+			saa->channels[ch*3+2].envelope[RIGHT] = (15 - ::envelope[mode][step]) & mask;
+		} else {
+			saa->channels[ch*3+0].envelope[RIGHT] =
+			saa->channels[ch*3+1].envelope[RIGHT] =
+			saa->channels[ch*3+2].envelope[RIGHT] = ::envelope[mode][step] & mask;
+		}
+	} else {
+		/* envelope mode off, set all envelope factors to 16 */
+		saa->channels[ch*3+0].envelope[ LEFT] =
+		saa->channels[ch*3+1].envelope[ LEFT] =
+		saa->channels[ch*3+2].envelope[ LEFT] =
+		saa->channels[ch*3+0].envelope[RIGHT] =
+		saa->channels[ch*3+1].envelope[RIGHT] =
+		saa->channels[ch*3+2].envelope[RIGHT] = 16;
+	}
+}
+
+void CMSEmulator::update(int chip, int16 *buffer, int length) {
+	struct SAA1099 *saa = &_saa1099[chip];
+	int j, ch;
+
+	/* if the channels are disabled we're done */
+	if (!saa->all_ch_enable) {
+		/* init output data */
+		if (chip == 0) {
+			memset(buffer, 0, sizeof(int16)*length*2);
+		}
+		return;
+	}
+
+	if (chip == 0) {
+		memset(buffer, 0, sizeof(int16)*length*2);
+	}
+
+	for (ch = 0; ch < 2; ch++) {
+		switch (saa->noise_params[ch]) {
+			case 0: saa->noise[ch].freq = 31250.0 * 2; break;
+			case 1: saa->noise[ch].freq = 15625.0 * 2; break;
+			case 2: saa->noise[ch].freq =  7812.5 * 2; break;
+			case 3: saa->noise[ch].freq = saa->channels[ch * 3].freq; break;
+		}
+	}
+
+	/* fill all data needed */
+	for (j = 0; j < length; ++j) {
+		int output_l = 0, output_r = 0;
+
+		/* for each channel */
+		for (ch = 0; ch < 6; ch++) {
+			if (saa->channels[ch].freq == 0.0)
+				saa->channels[ch].freq = (double)((2 * 15625) << saa->channels[ch].octave) /
+				(511.0 - (double)saa->channels[ch].frequency);
+
+			/* check the actual position in the square wave */
+			saa->channels[ch].counter -= saa->channels[ch].freq;
+			while (saa->channels[ch].counter < 0) {
+				/* calculate new frequency now after the half wave is updated */
+				saa->channels[ch].freq = (double)((2 * 15625) << saa->channels[ch].octave) /
+					(511.0 - (double)saa->channels[ch].frequency);
+
+				saa->channels[ch].counter += _sampleRate;
+				saa->channels[ch].level ^= 1;
+
+				/* eventually clock the envelope counters */
+				if (ch == 1 && saa->env_clock[0] == 0)
+					envelope(chip, 0);
+				if (ch == 4 && saa->env_clock[1] == 0)
+					envelope(chip, 1);
+			}
+
+			/* if the noise is enabled */
+			if (saa->channels[ch].noise_enable) {
+				/* if the noise level is high (noise 0: chan 0-2, noise 1: chan 3-5) */
+				if (saa->noise[ch/3].level & 1) {
+					/* subtract to avoid overflows, also use only half amplitude */
+					output_l -= saa->channels[ch].amplitude[ LEFT] * saa->channels[ch].envelope[ LEFT] / 16 / 2;
+					output_r -= saa->channels[ch].amplitude[RIGHT] * saa->channels[ch].envelope[RIGHT] / 16 / 2;
+				}
+			}
+
+			/* if the square wave is enabled */
+			if (saa->channels[ch].freq_enable) {
+				/* if the channel level is high */
+				if (saa->channels[ch].level & 1) {
+					output_l += saa->channels[ch].amplitude[ LEFT] * saa->channels[ch].envelope[ LEFT] / 16;
+					output_r += saa->channels[ch].amplitude[RIGHT] * saa->channels[ch].envelope[RIGHT] / 16;
+				}
+			}
+		}
+
+		for (ch = 0; ch < 2; ch++) {
+			/* check the actual position in noise generator */
+			saa->noise[ch].counter -= saa->noise[ch].freq;
+			while (saa->noise[ch].counter < 0) {
+				saa->noise[ch].counter += _sampleRate;
+				if (((saa->noise[ch].level & 0x4000) == 0) == ((saa->noise[ch].level & 0x0040) == 0) )
+					saa->noise[ch].level = (saa->noise[ch].level << 1) | 1;
+				else
+					saa->noise[ch].level <<= 1;
+			}
+		}
+		/* write sound data to the buffer */
+		buffer[j*2] += output_l / 6;
+		buffer[j*2+1] += output_r / 6;
+	}
+}
+
+void CMSEmulator::portWriteIntern(int chip, int offset, int data) {
+	SAA1099 *saa = &_saa1099[chip];
+	int reg = saa->selected_reg;
+	int ch;
+
+	switch (reg) {
+		/* channel i amplitude */
+		case 0x00:
+		case 0x01:
+		case 0x02:
+		case 0x03:
+		case 0x04:
+		case 0x05:
+			ch = reg & 7;
+			saa->channels[ch].amplitude[LEFT] = amplitude_lookup[data & 0x0f];
+			saa->channels[ch].amplitude[RIGHT] = amplitude_lookup[(data >> 4) & 0x0f];
+			break;
+
+		/* channel i frequency */
+		case 0x08:
+		case 0x09:
+		case 0x0a:
+		case 0x0b:
+		case 0x0c:
+		case 0x0d:
+			ch = reg & 7;
+			saa->channels[ch].frequency = data & 0xff;
+			break;
+
+		/* channel i octave */
+		case 0x10:
+		case 0x11:
+		case 0x12:
+			ch = (reg - 0x10) << 1;
+			saa->channels[ch + 0].octave = data & 0x07;
+			saa->channels[ch + 1].octave = (data >> 4) & 0x07;
+			break;
+
+		/* channel i frequency enable */
+		case 0x14:
+			saa->channels[0].freq_enable = data & 0x01;
+			saa->channels[1].freq_enable = data & 0x02;
+			saa->channels[2].freq_enable = data & 0x04;
+			saa->channels[3].freq_enable = data & 0x08;
+			saa->channels[4].freq_enable = data & 0x10;
+			saa->channels[5].freq_enable = data & 0x20;
+			break;
+
+		/* channel i noise enable */
+		case 0x15:
+			saa->channels[0].noise_enable = data & 0x01;
+			saa->channels[1].noise_enable = data & 0x02;
+			saa->channels[2].noise_enable = data & 0x04;
+			saa->channels[3].noise_enable = data & 0x08;
+			saa->channels[4].noise_enable = data & 0x10;
+			saa->channels[5].noise_enable = data & 0x20;
+			break;
+
+		/* noise generators parameters */
+		case 0x16:
+			saa->noise_params[0] = data & 0x03;
+			saa->noise_params[1] = (data >> 4) & 0x03;
+			break;
+
+		/* envelope generators parameters */
+		case 0x18:
+		case 0x19:
+			ch = reg - 0x18;
+			saa->env_reverse_right[ch] = data & 0x01;
+			saa->env_mode[ch] = (data >> 1) & 0x07;
+			saa->env_bits[ch] = data & 0x10;
+			saa->env_clock[ch] = data & 0x20;
+			saa->env_enable[ch] = data & 0x80;
+			/* reset the envelope */
+			saa->env_step[ch] = 0;
+			break;
+
+		/* channels enable & reset generators */
+		case 0x1c:
+			saa->all_ch_enable = data & 0x01;
+			saa->sync_state = data & 0x02;
+			if (data & 0x02) {
+				int i;
+				/* Synch & Reset generators */
+				for (i = 0; i < 6; i++) {
+					saa->channels[i].level = 0;
+					saa->channels[i].counter = 0.0;
+				}
+			}
+			break;
+
+		default:	/* Error! */
+			error("CMS Unkown write to reg %x with %x",reg, data);
+	}
+}
+
diff --git a/sound/softsynth/cms.h b/sound/softsynth/cms.h
new file mode 100644
index 0000000000..d5bb7f0a42
--- /dev/null
+++ b/sound/softsynth/cms.h
@@ -0,0 +1,92 @@
+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * $URL$
+ * $Id$
+ */
+
+#ifndef SOUND_SOFTSYNTH_CMS_H
+#define SOUND_SOFTSYNTH_CMS_H
+
+#include "common/scummsys.h"
+
+/* this structure defines a channel */
+struct saa1099_channel {
+	int frequency;				/* frequency (0x00..0xff) */
+	int freq_enable;			/* frequency enable */
+	int noise_enable;			/* noise enable */
+	int octave;				/* octave (0x00..0x07) */
+	int amplitude[2];			/* amplitude (0x00..0x0f) */
+	int envelope[2];			/* envelope (0x00..0x0f or 0x10 == off) */
+
+	/* vars to simulate the square wave */
+	double counter;
+	double freq;
+	int level;
+};
+
+/* this structure defines a noise channel */
+struct saa1099_noise {
+	/* vars to simulate the noise generator output */
+	double counter;
+	double freq;
+	int level;				/* noise polynomal shifter */
+};
+
+/* this structure defines a SAA1099 chip */
+struct SAA1099 {
+	int stream;				/* our stream */
+	int noise_params[2];			/* noise generators parameters */
+	int env_enable[2];			/* envelope generators enable */
+	int env_reverse_right[2];		/* envelope reversed for right channel */
+	int env_mode[2];			/* envelope generators mode */
+	int env_bits[2];			/* non zero = 3 bits resolution */
+	int env_clock[2];			/* envelope clock mode (non-zero external) */
+	int env_step[2];			/* current envelope step */
+	int all_ch_enable;			/* all channels enable */
+	int sync_state;				/* sync all channels */
+	int selected_reg;			/* selected register */
+	struct saa1099_channel channels[6];	/* channels */
+	struct saa1099_noise noise[2];		/* noise generators */
+};
+
+class CMSEmulator {
+public:
+	CMSEmulator(uint32 sampleRate) {
+		_sampleRate = sampleRate;
+		memset(_saa1099, 0, sizeof(SAA1099)*2);
+	}
+
+	~CMSEmulator() { }
+
+	void portWrite(int port, int val);
+	void readBuffer(int16 *buffer, const int numSamples);
+private:
+	uint32 _sampleRate;
+
+	SAA1099 _saa1099[2];
+
+	void envelope(int chip, int ch);
+	void update(int chip, int16 *buffer, int length);
+	void portWriteIntern(int chip, int offset, int data);
+};
+
+
+#endif