Hook DBOPL into OPL library and remove FMOPL. Does not generate any

sound yet.

Subversion-branch: /trunk/chocolate-doom
Subversion-revision: 1956

6 files changed, 143 insertions, 1400 deletions

diff --git a/opl/Makefile.am b/opl/Makefile.am
index d099b875..be1619d8 100644
--- a/opl/Makefile.am
+++ b/opl/Makefile.am
@@ -15,5 +15,5 @@ libopl_a_SOURCES =                                \
         opl_timer.c         opl_timer.h           \
         opl_win32.c                               \
         ioperm_sys.c        ioperm_sys.h          \
-        fmopl.c             fmopl.h
+        dbopl.c             dbopl.h
 
diff --git a/opl/dbopl.c b/opl/dbopl.c
index 556c570d..a4bd6fe5 100644
--- a/opl/dbopl.c
+++ b/opl/dbopl.c
@@ -324,7 +324,7 @@ static const WaveHandler WaveHandlerTable[8] = {
 */
 
 //We zero out when rate == 0
-inline void Operator__UpdateAttack(Operator *self, const Chip* chip ) {
+static inline void Operator__UpdateAttack(Operator *self, const Chip* chip ) {
 	Bit8u rate = self->reg60 >> 4;
 	if ( rate ) {
 		Bit8u val = (rate << 2) + self->ksr;
@@ -335,7 +335,7 @@ inline void Operator__UpdateAttack(Operator *self, const Chip* chip ) {
 		self->rateZero |= (1 << ATTACK);
 	}
 }
-inline void Operator__UpdateDecay(Operator *self, const Chip* chip ) {
+static inline void Operator__UpdateDecay(Operator *self, const Chip* chip ) {
 	Bit8u rate = self->reg60 & 0xf;
 	if ( rate ) {
 		Bit8u val = (rate << 2) + self->ksr;
@@ -346,7 +346,7 @@ inline void Operator__UpdateDecay(Operator *self, const Chip* chip ) {
 		self->rateZero |= (1 << DECAY);
 	}
 }
-inline void Operator__UpdateRelease(Operator *self, const Chip* chip ) {
+static inline void Operator__UpdateRelease(Operator *self, const Chip* chip ) {
 	Bit8u rate = self->reg80 & 0xf;
 	if ( rate ) {
 		Bit8u val = (rate << 2) + self->ksr;
@@ -364,7 +364,7 @@ inline void Operator__UpdateRelease(Operator *self, const Chip* chip ) {
 	}
 }
 
-inline void Operator__UpdateAttenuation(Operator *self) {
+static inline void Operator__UpdateAttenuation(Operator *self) {
 	Bit8u kslBase = (Bit8u)((self->chanData >> SHIFT_KSLBASE) & 0xff);
 	Bit32u tl = self->reg40 & 0x3f;
 	Bit8u kslShift = KslShiftTable[ self->reg40 >> 6 ];
@@ -373,7 +373,7 @@ inline void Operator__UpdateAttenuation(Operator *self) {
 	self->totalLevel += ( kslBase << ENV_EXTRA ) >> kslShift;
 }
 
-void Operator__UpdateFrequency(Operator *self) {
+static void Operator__UpdateFrequency(Operator *self) {
 	Bit32u freq = self->chanData & (( 1 << 10 ) - 1);
 	Bit32u block = (self->chanData >> 10) & 0xff;
 #ifdef WAVE_PRECISION
@@ -396,7 +396,7 @@ void Operator__UpdateFrequency(Operator *self) {
 	}
 }
 
-void Operator__UpdateRates(Operator *self, const Chip* chip ) {
+static void Operator__UpdateRates(Operator *self, const Chip* chip ) {
 	//Mame seems to reverse this where enabling ksr actually lowers
 	//the rate, but pdf manuals says otherwise?
 	Bit8u newKsr = (Bit8u)((self->chanData >> SHIFT_KEYCODE) & 0xff);
@@ -489,7 +489,7 @@ static const VolumeHandler VolumeHandlerTable[5] = {
 };
 
 static inline Bitu Operator__ForwardVolume(Operator *self) {
-	return self->currentLevel + (self->volHandler)();
+	return self->currentLevel + (self->volHandler)(self);
 }
 
 
@@ -498,7 +498,7 @@ static inline Bitu Operator__ForwardWave(Operator *self) {
 	return self->waveIndex >> WAVE_SH;
 }
 
-void Operator__Write20(Operator *self, const Chip* chip, Bit8u val ) {
+static void Operator__Write20(Operator *self, const Chip* chip, Bit8u val ) {
 	Bit8u change = (self->reg20 ^ val );
 	if ( !change ) 
 		return;
@@ -523,14 +523,14 @@ void Operator__Write20(Operator *self, const Chip* chip, Bit8u val ) {
 	}
 }
 
-void Operator__Write40(Operator *self, const Chip *chip, Bit8u val ) {
+static void Operator__Write40(Operator *self, const Chip *chip, Bit8u val ) {
 	if (!(self->reg40 ^ val )) 
 		return;
 	self->reg40 = val;
 	Operator__UpdateAttenuation( self );
 }
 
-void Operator__Write60(Operator *self, const Chip* chip, Bit8u val ) {
+static void Operator__Write60(Operator *self, const Chip* chip, Bit8u val ) {
 	Bit8u change = self->reg60 ^ val;
 	self->reg60 = val;
 	if ( change & 0x0f ) {
@@ -541,7 +541,7 @@ void Operator__Write60(Operator *self, const Chip* chip, Bit8u val ) {
 	}
 }
 
-void Operator__Write80(Operator *self, const Chip* chip, Bit8u val ) {
+static void Operator__Write80(Operator *self, const Chip* chip, Bit8u val ) {
 	Bit8u change = (self->reg80 ^ val );
 	if ( !change ) 
 		return;
@@ -555,7 +555,7 @@ void Operator__Write80(Operator *self, const Chip* chip, Bit8u val ) {
 	}
 }
 
-void Operator__WriteE0(Operator *self, const Chip* chip, Bit8u val ) {
+static void Operator__WriteE0(Operator *self, const Chip* chip, Bit8u val ) {
 	if ( !(self->regE0 ^ val) ) 
 		return;
 	//in opl3 mode you can always selet 7 waveforms regardless of waveformselect
@@ -596,7 +596,7 @@ static inline void Operator__Prepare(Operator *self, const Chip* chip )  {
 	}
 }
 
-void Operator__KeyOn(Operator *self, Bit8u mask ) {
+static void Operator__KeyOn(Operator *self, Bit8u mask ) {
 	if ( !self->keyOn ) {
 		//Restart the frequency generator
 #if( DBOPL_WAVE > WAVE_HANDLER )
@@ -610,7 +610,7 @@ void Operator__KeyOn(Operator *self, Bit8u mask ) {
 	self->keyOn |= mask;
 }
 
-void Operator__KeyOff(Operator *self, Bit8u mask ) {
+static void Operator__KeyOff(Operator *self, Bit8u mask ) {
 	self->keyOn &= ~mask;
 	if ( !self->keyOn ) {
 		if ( self->state != OFF ) {
@@ -649,7 +649,7 @@ static inline Bits Operator__GetSample(Operator *self, Bits modulation ) {
 	}
 }
 
-void Operator__Operator(Operator *self) {
+static void Operator__Operator(Operator *self) {
 	self->chanData = 0;
 	self->freqMul = 0;
 	self->waveIndex = 0;
@@ -675,7 +675,7 @@ void Operator__Operator(Operator *self) {
 	Channel
 */
 
-void Channel__Channel(Channel *self) {
+static void Channel__Channel(Channel *self) {
         Operator__Operator(&self->op[0]);
         Operator__Operator(&self->op[1]);
 	self->old[0] = self->old[1] = 0;
@@ -693,7 +693,7 @@ static inline Operator* Channel__Op( Channel *self, Bitu index ) {
         return &( ( self + (index >> 1) )->op[ index & 1 ]);
 }
 
-void Channel__SetChanData(Channel *self, const Chip* chip, Bit32u data ) {
+static void Channel__SetChanData(Channel *self, const Chip* chip, Bit32u data ) {
 	Bit32u change = self->chanData ^ data;
 	self->chanData = data;
 	Channel__Op( self, 0 )->chanData = data;
@@ -711,7 +711,7 @@ void Channel__SetChanData(Channel *self, const Chip* chip, Bit32u data ) {
 	}
 }
 
-void Channel__UpdateFrequency(Channel *self, const Chip* chip, Bit8u fourOp ) {
+static void Channel__UpdateFrequency(Channel *self, const Chip* chip, Bit8u fourOp ) {
 	//Extrace the frequency bits
 	Bit32u data = self->chanData & 0xffff;
 	Bit32u kslBase = KslTable[ data >> 6 ];
@@ -729,7 +729,7 @@ void Channel__UpdateFrequency(Channel *self, const Chip* chip, Bit8u fourOp ) {
 	}
 }
 
-void Channel__WriteA0(Channel *self, const Chip* chip, Bit8u val ) {
+static void Channel__WriteA0(Channel *self, const Chip* chip, Bit8u val ) {
 	Bit8u fourOp = chip->reg104 & chip->opl3Active & self->fourMask;
 	//Don't handle writes to silent fourop channels
 	if ( fourOp > 0x80 )
@@ -741,7 +741,7 @@ void Channel__WriteA0(Channel *self, const Chip* chip, Bit8u val ) {
 	}
 }
 
-void Channel__WriteB0(Channel *self, const Chip* chip, Bit8u val ) {
+static void Channel__WriteB0(Channel *self, const Chip* chip, Bit8u val ) {
 	Bit8u fourOp = chip->reg104 & chip->opl3Active & self->fourMask;
 	//Don't handle writes to silent fourop channels
 	if ( fourOp > 0x80 )
@@ -772,7 +772,7 @@ void Channel__WriteB0(Channel *self, const Chip* chip, Bit8u val ) {
 	}
 }
 
-void Channel__WriteC0(Channel *self, const Chip* chip, Bit8u val ) {
+static void Channel__WriteC0(Channel *self, const Chip* chip, Bit8u val ) {
 	Bit8u change = val ^ self->regC0;
 	if ( !change )
 		return;
@@ -838,7 +838,7 @@ void Channel__WriteC0(Channel *self, const Chip* chip, Bit8u val ) {
 	}
 }
 
-void Channel__ResetC0(Channel *self, const Chip* chip ) {
+static void Channel__ResetC0(Channel *self, const Chip* chip ) {
 	Bit8u val = self->regC0;
 	self->regC0 ^= 0xff;
 	Channel__WriteC0( self, chip, val );
@@ -975,7 +975,7 @@ Channel* Channel__BlockTemplate(Channel *self, Chip* chip,
 		Bit32s mod = (Bit32u)((self->old[0] + self->old[1])) >> self->feedback;
 		self->old[0] = self->old[1];
 		self->old[1] = Operator__GetSample( Channel__Op(self, 0), mod );
-		Bit32s sample;
+		Bit32s sample = 0;
 		Bit32s out0 = self->old[0];
 		if ( mode == sm2AM || mode == sm3AM ) {
 			sample = out0 + Operator__GetSample( Channel__Op(self, 1), 0 );
@@ -1095,7 +1095,7 @@ static inline Bit32u Chip__ForwardLFO(Chip *self, Bit32u samples ) {
 }
 
 
-void Chip__WriteBD(Chip *self, Bit8u val ) {
+static void Chip__WriteBD(Chip *self, Bit8u val ) {
 	Bit8u change = self->regBD ^ val;
 	if ( !change )
 		return;
@@ -1240,7 +1240,7 @@ void Chip__WriteReg(Chip *self, Bit32u reg, Bit8u val ) {
 }
 
 
-Bit32u Chip__WriteAddr(Chip *self, Bit32u port, Bit8u val ) {
+static Bit32u Chip__WriteAddr(Chip *self, Bit32u port, Bit8u val ) {
 	switch ( port & 3 ) {
 	case 0:
 		return val;
@@ -1415,7 +1415,7 @@ void Chip__Setup(Chip *self, Bit32u rate ) {
 }
 
 static int doneTables = FALSE;
-void InitTables( void ) {
+void DBOPL_InitTables( void ) {
         int i, oct;
 
 	if ( doneTables )
diff --git a/opl/dbopl.h b/opl/dbopl.h
index f7d2e416..a5c10bfd 100644
--- a/opl/dbopl.h
+++ b/opl/dbopl.h
@@ -47,7 +47,7 @@ typedef Bits ( DB_FASTCALL *WaveHandler) ( Bitu i, Bitu volume );
 
 #define DB_FASTCALL
 
-typedef Bits (*VolumeHandler)();
+typedef Bits (*VolumeHandler)(Operator *self);
 typedef Channel* (*SynthHandler)(Channel *self, Chip* chip, Bit32u samples, Bit32s* output );
 
 //Different synth modes that can generate blocks of data
@@ -194,3 +194,10 @@ struct Handler : public Adlib::Handler {
 */
 
 
+void Chip__Setup(Chip *self, Bit32u rate );
+void DBOPL_InitTables( void );
+void Chip__Chip(Chip *self);
+void Chip__WriteReg(Chip *self, Bit32u reg, Bit8u val );
+void Chip__GenerateBlock2(Chip *self, Bitu total, Bit32s* output );
+
+
diff --git a/opl/fmopl.c b/opl/fmopl.c
deleted file mode 100644
index 1671244e..00000000
--- a/opl/fmopl.c
+++ /dev/null
@@ -1,1155 +0,0 @@
-/* This file is derived from fmopl.cpp from ScummVM.
- *
- * 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.
- *
- * LGPL licensed version of MAMEs fmopl (V0.37a modified) by
- * Tatsuyuki Satoh. Included from LGPL'ed AdPlug.
- */
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <stdarg.h>
-#include <math.h>
-
-#include "fmopl.h"
-
-#define PI 3.1415926539
-
-#define CLIP(value, min, max)                      \
-    ( (value) < (min) ? (min) :                    \
-      (value) > (max) ? (max) : (value) )
-
-/* -------------------- preliminary define section --------------------- */
-/* attack/decay rate time rate */
-#define OPL_ARRATE     141280  /* RATE 4 =  2826.24ms @ 3.6MHz */
-#define OPL_DRRATE    1956000  /* RATE 4 = 39280.64ms @ 3.6MHz */
-
-#define FREQ_BITS 24			/* frequency turn          */
-
-/* counter bits = 20 , octerve 7 */
-#define FREQ_RATE   (1<<(FREQ_BITS-20))
-#define TL_BITS    (FREQ_BITS+2)
-
-/* final output shift , limit minimum and maximum */
-#define OPL_OUTSB   (TL_BITS+3-16)		/* OPL output final shift 16bit */
-#define OPL_MAXOUT (0x7fff<<OPL_OUTSB)
-#define OPL_MINOUT (-0x8000<<OPL_OUTSB)
-
-/* -------------------- quality selection --------------------- */
-
-/* sinwave entries */
-/* used static memory = SIN_ENT * 4 (byte) */
-#define SIN_ENT_SHIFT 11
-#define SIN_ENT (1<<SIN_ENT_SHIFT)
-
-/* output level entries (envelope,sinwave) */
-/* envelope counter lower bits */
-static int ENV_BITS;
-/* envelope output entries */
-static int EG_ENT;
-
-/* used dynamic memory = EG_ENT*4*4(byte)or EG_ENT*6*4(byte) */
-/* used static  memory = EG_ENT*4 (byte)                     */
-static int EG_OFF;								 /* OFF */
-static int EG_DED;
-static int EG_DST;								 /* DECAY START */
-static int EG_AED;
-#define EG_AST   0                       /* ATTACK START */
-
-#define EG_STEP (96.0/EG_ENT) /* OPL is 0.1875 dB step  */
-
-/* LFO table entries */
-#define VIB_ENT 512
-#define VIB_SHIFT (32-9)
-#define AMS_ENT 512
-#define AMS_SHIFT (32-9)
-
-#define VIB_RATE_SHIFT 8
-#define VIB_RATE (1<<VIB_RATE_SHIFT)
-
-/* -------------------- local defines , macros --------------------- */
-
-/* register number to channel number , slot offset */
-#define SLOT1 0
-#define SLOT2 1
-
-/* envelope phase */
-#define ENV_MOD_RR  0x00
-#define ENV_MOD_DR  0x01
-#define ENV_MOD_AR  0x02
-
-/* -------------------- tables --------------------- */
-static const int slot_array[32] = {
-	 0, 2, 4, 1, 3, 5,-1,-1,
-	 6, 8,10, 7, 9,11,-1,-1,
-	12,14,16,13,15,17,-1,-1,
-	-1,-1,-1,-1,-1,-1,-1,-1
-};
-
-static uint32_t KSL_TABLE[8 * 16];
-
-static const double KSL_TABLE_SEED[8 * 16] = {
-	/* OCT 0 */
-	0.000, 0.000, 0.000, 0.000,
-	0.000, 0.000, 0.000, 0.000,
-	0.000, 0.000, 0.000, 0.000,
-	0.000, 0.000, 0.000, 0.000,
-	/* OCT 1 */
-	0.000, 0.000, 0.000, 0.000,
-	0.000, 0.000, 0.000, 0.000,
-	0.000, 0.750, 1.125, 1.500,
-	1.875, 2.250, 2.625, 3.000,
-	/* OCT 2 */
-	0.000, 0.000, 0.000, 0.000,
-	0.000, 1.125, 1.875, 2.625,
-	3.000, 3.750, 4.125, 4.500,
-	4.875, 5.250, 5.625, 6.000,
-	/* OCT 3 */
-	0.000, 0.000, 0.000, 1.875,
-	3.000, 4.125, 4.875, 5.625,
-	6.000, 6.750, 7.125, 7.500,
-	7.875, 8.250, 8.625, 9.000,
-	/* OCT 4 */
-	0.000, 0.000, 3.000, 4.875,
-	6.000, 7.125, 7.875, 8.625,
-	9.000, 9.750, 10.125, 10.500,
-	10.875, 11.250, 11.625, 12.000,
-	/* OCT 5 */
-	0.000, 3.000, 6.000, 7.875,
-	9.000, 10.125, 10.875, 11.625,
-	12.000, 12.750, 13.125, 13.500,
-	13.875, 14.250, 14.625, 15.000,
-	/* OCT 6 */
-	0.000, 6.000, 9.000, 10.875,
-	12.000, 13.125, 13.875, 14.625,
-	15.000, 15.750, 16.125, 16.500,
-	16.875, 17.250, 17.625, 18.000,
-	/* OCT 7 */
-	0.000, 9.000, 12.000, 13.875,
-	15.000, 16.125, 16.875, 17.625,
-	18.000, 18.750, 19.125, 19.500,
-	19.875, 20.250, 20.625, 21.000
-};
-
-/* sustain level table (3db per step) */
-/* 0 - 15: 0, 3, 6, 9,12,15,18,21,24,27,30,33,36,39,42,93 (dB)*/
-
-static int SL_TABLE[16];
-
-static const uint32_t SL_TABLE_SEED[16] = {
-	0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 31
-};
-
-#define TL_MAX (EG_ENT * 2) /* limit(tl + ksr + envelope) + sinwave */
-/* TotalLevel : 48 24 12  6  3 1.5 0.75 (dB) */
-/* TL_TABLE[ 0      to TL_MAX          ] : plus  section */
-/* TL_TABLE[ TL_MAX to TL_MAX+TL_MAX-1 ] : minus section */
-static int *TL_TABLE;
-
-/* pointers to TL_TABLE with sinwave output offset */
-static int **SIN_TABLE;
-
-/* LFO table */
-static int *AMS_TABLE;
-static int *VIB_TABLE;
-
-/* envelope output curve table */
-/* attack + decay + OFF */
-//static int ENV_CURVE[2*EG_ENT+1];
-//static int ENV_CURVE[2 * 4096 + 1];   // to keep it static ...
-static int *ENV_CURVE;
-
-
-/* multiple table */
-#define ML(a) (int)(a * 2)
-static const uint32_t MUL_TABLE[16]= {
-/* 1/2, 1, 2, 3, 4, 5, 6, 7, 8, 9,10,11,12,13,14,15 */
-	ML(0.50), ML(1.00), ML(2.00),  ML(3.00), ML(4.00), ML(5.00), ML(6.00), ML(7.00),
-	ML(8.00), ML(9.00), ML(10.00), ML(10.00),ML(12.00),ML(12.00),ML(15.00),ML(15.00)
-};
-#undef ML
-
-/* dummy attack / decay rate ( when rate == 0 ) */
-static int RATE_0[16]=
-{0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
-
-/* -------------------- static state --------------------- */
-
-/* lock level of common table */
-static int num_lock = 0;
-
-/* work table */
-static void *cur_chip = NULL;	/* current chip point */
-/* currenct chip state */
-/* static OPLSAMPLE  *bufL,*bufR; */
-static OPL_CH *S_CH;
-static OPL_CH *E_CH;
-static OPL_SLOT *SLOT7_1, *SLOT7_2, *SLOT8_1, *SLOT8_2;
-
-static int outd[1];
-static int ams;
-static int vib;
-static int *ams_table;
-static int *vib_table;
-static int amsIncr;
-static int vibIncr;
-static int feedback2;		/* connect for SLOT 2 */
-
-/* --------------------- rebuild tables ------------------- */
-
-#define ARRAYSIZE(x) (sizeof(x) / sizeof(*x))
-#define SC_KSL(mydb) ((uint32_t) (mydb / (EG_STEP / 2)))
-#define SC_SL(db) (int)(db * ((3 / EG_STEP) * (1 << ENV_BITS))) + EG_DST
-
-void OPLBuildTables(int ENV_BITS_PARAM, int EG_ENT_PARAM) {
-	int i;
-
-	ENV_BITS = ENV_BITS_PARAM;
-	EG_ENT = EG_ENT_PARAM;
-	EG_OFF = ((2 * EG_ENT)<<ENV_BITS);  /* OFF          */
-	EG_DED = EG_OFF;
-	EG_DST = (EG_ENT << ENV_BITS);     /* DECAY  START */
-	EG_AED = EG_DST;
-	//EG_STEP = (96.0/EG_ENT);
-
-	for (i = 0; i < ARRAYSIZE(KSL_TABLE_SEED); i++)
-		KSL_TABLE[i] = SC_KSL(KSL_TABLE_SEED[i]);
-
-	for (i = 0; i < ARRAYSIZE(SL_TABLE_SEED); i++)
-		SL_TABLE[i] = SC_SL(SL_TABLE_SEED[i]);
-}
-
-#undef SC_KSL
-#undef SC_SL
-
-/* --------------------- subroutines  --------------------- */
-
-/* status set and IRQ handling */
-static inline void OPL_STATUS_SET(FM_OPL *OPL, int flag) {
-	/* set status flag */
-	OPL->status |= flag;
-	if(!(OPL->status & 0x80)) {
-		if(OPL->status & OPL->statusmask) {	/* IRQ on */
-			OPL->status |= 0x80;
-			/* callback user interrupt handler (IRQ is OFF to ON) */
-			if(OPL->IRQHandler)
-				(OPL->IRQHandler)(OPL->IRQParam,1);
-		}
-	}
-}
-
-/* status reset and IRQ handling */
-static inline void OPL_STATUS_RESET(FM_OPL *OPL, int flag) {
-	/* reset status flag */
-	OPL->status &= ~flag;
-	if((OPL->status & 0x80)) {
-		if (!(OPL->status & OPL->statusmask)) {
-			OPL->status &= 0x7f;
-			/* callback user interrupt handler (IRQ is ON to OFF) */
-			if(OPL->IRQHandler) (OPL->IRQHandler)(OPL->IRQParam,0);
-		}
-	}
-}
-
-/* IRQ mask set */
-static inline void OPL_STATUSMASK_SET(FM_OPL *OPL, int flag) {
-	OPL->statusmask = flag;
-	/* IRQ handling check */
-	OPL_STATUS_SET(OPL,0);
-	OPL_STATUS_RESET(OPL,0);
-}
-
-/* ----- key on  ----- */
-static inline void OPL_KEYON(OPL_SLOT *SLOT) {
-	/* sin wave restart */
-	SLOT->Cnt = 0;
-	/* set attack */
-	SLOT->evm = ENV_MOD_AR;
-	SLOT->evs = SLOT->evsa;
-	SLOT->evc = EG_AST;
-	SLOT->eve = EG_AED;
-}
-
-/* ----- key off ----- */
-static inline void OPL_KEYOFF(OPL_SLOT *SLOT) {
-	if( SLOT->evm > ENV_MOD_RR) {
-		/* set envelope counter from envleope output */
-
-		// WORKAROUND: The Kyra engine does something very strange when
-		// starting a new song. For each channel:
-		//
-		// * The release rate is set to "fastest".
-		// * Any note is keyed off.
-		// * A very low-frequency note is keyed on.
-		//
-		// Usually, what happens next is that the real notes is keyed
-		// on immediately, in which case there's no problem.
-		//
-		// However, if the note is again keyed off (because the channel
-		// begins on a rest rather than a note), the envelope counter
-		// was moved from the very lowest point on the attack curve to
-		// the very highest point on the release curve.
-		//
-		// Again, this might not be a problem, if the release rate is
-		// still set to "fastest". But in many cases, it had already
-		// been increased. And, possibly because of inaccuracies in the
-		// envelope generator, that would cause the note to "fade out"
-		// for quite a long time.
-		//
-		// What we really need is a way to find the correct starting
-		// point for the envelope counter, and that may be what the
-		// commented-out line below is meant to do. For now, simply
-		// handle the pathological case.
-
-		if (SLOT->evm == ENV_MOD_AR && SLOT->evc == EG_AST)
-			SLOT->evc = EG_DED;
-		else if( !(SLOT->evc & EG_DST) )
-			//SLOT->evc = (ENV_CURVE[SLOT->evc>>ENV_BITS]<<ENV_BITS) + EG_DST;
-			SLOT->evc = EG_DST;
-		SLOT->eve = EG_DED;
-		SLOT->evs = SLOT->evsr;
-		SLOT->evm = ENV_MOD_RR;
-	}
-}
-
-/* ---------- calcrate Envelope Generator & Phase Generator ---------- */
-
-/* return : envelope output */
-static inline uint32_t OPL_CALC_SLOT(OPL_SLOT *SLOT) {
-	/* calcrate envelope generator */
-	if((SLOT->evc += SLOT->evs) >= SLOT->eve) {
-		switch( SLOT->evm ) {
-		case ENV_MOD_AR: /* ATTACK -> DECAY1 */
-			/* next DR */
-			SLOT->evm = ENV_MOD_DR;
-			SLOT->evc = EG_DST;
-			SLOT->eve = SLOT->SL;
-			SLOT->evs = SLOT->evsd;
-			break;
-		case ENV_MOD_DR: /* DECAY -> SL or RR */
-			SLOT->evc = SLOT->SL;
-			SLOT->eve = EG_DED;
-			if(SLOT->eg_typ) {
-				SLOT->evs = 0;
-			} else {
-				SLOT->evm = ENV_MOD_RR;
-				SLOT->evs = SLOT->evsr;
-			}
-			break;
-		case ENV_MOD_RR: /* RR -> OFF */
-			SLOT->evc = EG_OFF;
-			SLOT->eve = EG_OFF + 1;
-			SLOT->evs = 0;
-			break;
-		}
-	}
-	/* calcrate envelope */
-	return SLOT->TLL + ENV_CURVE[SLOT->evc>>ENV_BITS] + (SLOT->ams ? ams : 0);
-}
-
-/* set algorythm connection */
-static void set_algorythm(OPL_CH *CH) {
-	int *carrier = &outd[0];
-	CH->connect1 = CH->CON ? carrier : &feedback2;
-	CH->connect2 = carrier;
-}
-
-/* ---------- frequency counter for operater update ---------- */
-static inline void CALC_FCSLOT(OPL_CH *CH, OPL_SLOT *SLOT) {
-	int ksr;
-
-	/* frequency step counter */
-	SLOT->Incr = CH->fc * SLOT->mul;
-	ksr = CH->kcode >> SLOT->KSR;
-
-	if( SLOT->ksr != ksr ) {
-		SLOT->ksr = ksr;
-		/* attack , decay rate recalcration */
-		SLOT->evsa = SLOT->AR[ksr];
-		SLOT->evsd = SLOT->DR[ksr];
-		SLOT->evsr = SLOT->RR[ksr];
-	}
-	SLOT->TLL = SLOT->TL + (CH->ksl_base>>SLOT->ksl);
-}
-
-/* set multi,am,vib,EG-TYP,KSR,mul */
-static inline void set_mul(FM_OPL *OPL, int slot, int v) {
-	OPL_CH   *CH   = &OPL->P_CH[slot>>1];
-	OPL_SLOT *SLOT = &CH->SLOT[slot & 1];
-
-	SLOT->mul    = MUL_TABLE[v & 0x0f];
-	SLOT->KSR    = (v & 0x10) ? 0 : 2;
-	SLOT->eg_typ = (v & 0x20) >> 5;
-	SLOT->vib    = (v & 0x40);
-	SLOT->ams    = (v & 0x80);
-	CALC_FCSLOT(CH, SLOT);
-}
-
-/* set ksl & tl */
-static inline void set_ksl_tl(FM_OPL *OPL, int slot, int v) {
-	OPL_CH   *CH   = &OPL->P_CH[slot>>1];
-	OPL_SLOT *SLOT = &CH->SLOT[slot & 1];
-	int ksl = v >> 6; /* 0 / 1.5 / 3 / 6 db/OCT */
-
-	SLOT->ksl = ksl ? 3-ksl : 31;
-	SLOT->TL  = (int)((v & 0x3f) * (0.75 / EG_STEP)); /* 0.75db step */
-
-	if(!(OPL->mode & 0x80)) {	/* not CSM latch total level */
-		SLOT->TLL = SLOT->TL + (CH->ksl_base >> SLOT->ksl);
-	}
-}
-
-/* set attack rate & decay rate  */
-static inline void set_ar_dr(FM_OPL *OPL, int slot, int v) {
-	OPL_CH   *CH   = &OPL->P_CH[slot>>1];
-	OPL_SLOT *SLOT = &CH->SLOT[slot & 1];
-	int ar = v >> 4;
-	int dr = v & 0x0f;
-
-	SLOT->AR = ar ? &OPL->AR_TABLE[ar << 2] : RATE_0;
-	SLOT->evsa = SLOT->AR[SLOT->ksr];
-	if(SLOT->evm == ENV_MOD_AR)
-		SLOT->evs = SLOT->evsa;
-
-	SLOT->DR = dr ? &OPL->DR_TABLE[dr<<2] : RATE_0;
-	SLOT->evsd = SLOT->DR[SLOT->ksr];
-	if(SLOT->evm == ENV_MOD_DR)
-		SLOT->evs = SLOT->evsd;
-}
-
-/* set sustain level & release rate */
-static inline void set_sl_rr(FM_OPL *OPL, int slot, int v) {
-	OPL_CH   *CH   = &OPL->P_CH[slot>>1];
-	OPL_SLOT *SLOT = &CH->SLOT[slot & 1];
-	int sl = v >> 4;
-	int rr = v & 0x0f;
-
-	SLOT->SL = SL_TABLE[sl];
-	if(SLOT->evm == ENV_MOD_DR)
-		SLOT->eve = SLOT->SL;
-	SLOT->RR = &OPL->DR_TABLE[rr<<2];
-	SLOT->evsr = SLOT->RR[SLOT->ksr];
-	if(SLOT->evm == ENV_MOD_RR)
-		SLOT->evs = SLOT->evsr;
-}
-
-/* operator output calcrator */
-
-#define OP_OUT(slot,env,con)   slot->wavetable[((slot->Cnt + con)>>(24-SIN_ENT_SHIFT)) & (SIN_ENT-1)][env]
-/* ---------- calcrate one of channel ---------- */
-static inline void OPL_CALC_CH(OPL_CH *CH) {
-	uint32_t env_out;
-	OPL_SLOT *SLOT;
-
-	feedback2 = 0;
-	/* SLOT 1 */
-	SLOT = &CH->SLOT[SLOT1];
-	env_out=OPL_CALC_SLOT(SLOT);
-	if(env_out < (uint32_t)(EG_ENT - 1)) {
-		/* PG */
-		if(SLOT->vib)
-			SLOT->Cnt += (SLOT->Incr * vib) >> VIB_RATE_SHIFT;
-		else
-			SLOT->Cnt += SLOT->Incr;
-		/* connection */
-		if(CH->FB) {
-			int feedback1 = (CH->op1_out[0] + CH->op1_out[1]) >> CH->FB;
-			CH->op1_out[1] = CH->op1_out[0];
-			*CH->connect1 += CH->op1_out[0] = OP_OUT(SLOT, env_out, feedback1);
-		} else {
-			*CH->connect1 += OP_OUT(SLOT, env_out, 0);
-		}
-	} else {
-		CH->op1_out[1] = CH->op1_out[0];
-		CH->op1_out[0] = 0;
-	}
-	/* SLOT 2 */
-	SLOT = &CH->SLOT[SLOT2];
-	env_out=OPL_CALC_SLOT(SLOT);
-	if(env_out < (uint32_t)(EG_ENT - 1)) {
-		/* PG */
-		if(SLOT->vib)
-			SLOT->Cnt += (SLOT->Incr * vib) >> VIB_RATE_SHIFT;
-		else
-			SLOT->Cnt += SLOT->Incr;
-		/* connection */
-		outd[0] += OP_OUT(SLOT, env_out, feedback2);
-	}
-}
-
-/* ---------- calcrate rythm block ---------- */
-#define WHITE_NOISE_db 6.0
-static inline void OPL_CALC_RH(FM_OPL *OPL, OPL_CH *CH) {
-	uint32_t env_tam, env_sd, env_top, env_hh;
-	// This code used to do int(OPL->rnd.getRandomBit() * (WHITE_NOISE_db / EG_STEP)),
-	// but EG_STEP = 96.0/EG_ENT, and WHITE_NOISE_db=6.0. So, that's equivalent to
-	// int(OPL->rnd.getRandomBit() * EG_ENT/16). We know that EG_ENT is 4096, or 1024,
-	// or 128, so we can safely avoid any FP ops.
-	int whitenoise = (rand() & 1) * (EG_ENT>>4);
-
-	int tone8;
-
-	OPL_SLOT *SLOT;
-	int env_out;
-
-	/* BD : same as FM serial mode and output level is large */
-	feedback2 = 0;
-	/* SLOT 1 */
-	SLOT = &CH[6].SLOT[SLOT1];
-	env_out = OPL_CALC_SLOT(SLOT);
-	if(env_out < EG_ENT-1) {
-		/* PG */
-		if(SLOT->vib)
-			SLOT->Cnt += (SLOT->Incr * vib) >> VIB_RATE_SHIFT;
-		else
-			SLOT->Cnt += SLOT->Incr;
-		/* connection */
-		if(CH[6].FB) {
-			int feedback1 = (CH[6].op1_out[0] + CH[6].op1_out[1]) >> CH[6].FB;
-			CH[6].op1_out[1] = CH[6].op1_out[0];
-			feedback2 = CH[6].op1_out[0] = OP_OUT(SLOT, env_out, feedback1);
-		}
-		else {
-			feedback2 = OP_OUT(SLOT, env_out, 0);
-		}
-	} else {
-		feedback2 = 0;
-		CH[6].op1_out[1] = CH[6].op1_out[0];
-		CH[6].op1_out[0] = 0;
-	}
-	/* SLOT 2 */
-	SLOT = &CH[6].SLOT[SLOT2];
-	env_out = OPL_CALC_SLOT(SLOT);
-	if(env_out < EG_ENT-1) {
-		/* PG */
-		if(SLOT->vib)
-			SLOT->Cnt += (SLOT->Incr * vib) >> VIB_RATE_SHIFT;
-		else
-			SLOT->Cnt += SLOT->Incr;
-		/* connection */
-		outd[0] += OP_OUT(SLOT, env_out, feedback2) * 2;
-	}
-
-	// SD  (17) = mul14[fnum7] + white noise
-	// TAM (15) = mul15[fnum8]
-	// TOP (18) = fnum6(mul18[fnum8]+whitenoise)
-	// HH  (14) = fnum7(mul18[fnum8]+whitenoise) + white noise
-	env_sd = OPL_CALC_SLOT(SLOT7_2) + whitenoise;
-	env_tam =OPL_CALC_SLOT(SLOT8_1);
-	env_top = OPL_CALC_SLOT(SLOT8_2);
-	env_hh = OPL_CALC_SLOT(SLOT7_1) + whitenoise;
-
-	/* PG */
-	if(SLOT7_1->vib)
-		SLOT7_1->Cnt += (SLOT7_1->Incr * vib) >> (VIB_RATE_SHIFT-1);
-	else
-		SLOT7_1->Cnt += 2 * SLOT7_1->Incr;
-	if(SLOT7_2->vib)
-		SLOT7_2->Cnt += (CH[7].fc * vib) >> (VIB_RATE_SHIFT-3);
-	else
-		SLOT7_2->Cnt += (CH[7].fc * 8);
-	if(SLOT8_1->vib)
-		SLOT8_1->Cnt += (SLOT8_1->Incr * vib) >> VIB_RATE_SHIFT;
-	else
-		SLOT8_1->Cnt += SLOT8_1->Incr;
-	if(SLOT8_2->vib)
-		SLOT8_2->Cnt += ((CH[8].fc * 3) * vib) >> (VIB_RATE_SHIFT-4);
-	else
-		SLOT8_2->Cnt += (CH[8].fc * 48);
-
-	tone8 = OP_OUT(SLOT8_2,whitenoise,0 );
-
-	/* SD */
-	if(env_sd < (uint32_t)(EG_ENT - 1))
-		outd[0] += OP_OUT(SLOT7_1, env_sd, 0) * 8;
-	/* TAM */
-	if(env_tam < (uint32_t)(EG_ENT - 1))
-		outd[0] += OP_OUT(SLOT8_1, env_tam, 0) * 2;
-	/* TOP-CY */
-	if(env_top < (uint32_t)(EG_ENT - 1))
-		outd[0] += OP_OUT(SLOT7_2, env_top, tone8) * 2;
-	/* HH */
-	if(env_hh  < (uint32_t)(EG_ENT-1))
-		outd[0] += OP_OUT(SLOT7_2, env_hh, tone8) * 2;
-}
-
-/* ----------- initialize time tabls ----------- */
-static void init_timetables(FM_OPL *OPL, int ARRATE, int DRRATE) {
-	int i;
-	double rate;
-
-	/* make attack rate & decay rate tables */
-	for (i = 0; i < 4; i++)
-		OPL->AR_TABLE[i] = OPL->DR_TABLE[i] = 0;
-	for (i = 4; i <= 60; i++) {
-		rate = OPL->freqbase;						/* frequency rate */
-		if(i < 60)
-			rate *= 1.0 + (i & 3) * 0.25;		/* b0-1 : x1 , x1.25 , x1.5 , x1.75 */
-		rate *= 1 << ((i >> 2) - 1);						/* b2-5 : shift bit */
-		rate *= (double)(EG_ENT << ENV_BITS);
-		OPL->AR_TABLE[i] = (int)(rate / ARRATE);
-		OPL->DR_TABLE[i] = (int)(rate / DRRATE);
-	}
-	for (i = 60; i < 76; i++) {
-		OPL->AR_TABLE[i] = EG_AED-1;
-		OPL->DR_TABLE[i] = OPL->DR_TABLE[60];
-	}
-}
-
-/* ---------- generic table initialize ---------- */
-static int OPLOpenTable(void) {
-	int s,t;
-	double rate;
-	int i,j;
-	double pom;
-
-	/* allocate dynamic tables */
-	if((TL_TABLE = (int *)malloc(TL_MAX * 2 * sizeof(int))) == NULL)
-		return 0;
-
-	if((SIN_TABLE = (int **)malloc(SIN_ENT * 4 * sizeof(int *))) == NULL) {
-		free(TL_TABLE);
-		return 0;
-	}
-
-	if((AMS_TABLE = (int *)malloc(AMS_ENT * 2 * sizeof(int))) == NULL) {
-		free(TL_TABLE);
-		free(SIN_TABLE);
-		return 0;
-	}
-
-	if((VIB_TABLE = (int *)malloc(VIB_ENT * 2 * sizeof(int))) == NULL) {
-		free(TL_TABLE);
-		free(SIN_TABLE);
-		free(AMS_TABLE);
-		return 0;
-	}
-	/* make total level table */
-	for (t = 0; t < EG_ENT - 1 ; t++) {
-		rate = ((1 << TL_BITS) - 1) / pow(10.0, EG_STEP * t / 20);	/* dB -> voltage */
-		TL_TABLE[         t] =  (int)rate;
-		TL_TABLE[TL_MAX + t] = -TL_TABLE[t];
-	}
-	/* fill volume off area */
-	for (t = EG_ENT - 1; t < TL_MAX; t++) {
-		TL_TABLE[t] = TL_TABLE[TL_MAX + t] = 0;
-	}
-
-	/* make sinwave table (total level offet) */
-	/* degree 0 = degree 180                   = off */
-	SIN_TABLE[0] = SIN_TABLE[SIN_ENT /2 ] = &TL_TABLE[EG_ENT - 1];
-	for (s = 1;s <= SIN_ENT / 4; s++) {
-		pom = sin(2 * PI * s / SIN_ENT); /* sin     */
-		pom = 20 * log10(1 / pom);	   /* decibel */
-		j = (int) (pom / EG_STEP);         /* TL_TABLE steps */
-
-		/* degree 0   -  90    , degree 180 -  90 : plus section */
-		SIN_TABLE[          s] = SIN_TABLE[SIN_ENT / 2 - s] = &TL_TABLE[j];
-		/* degree 180 - 270    , degree 360 - 270 : minus section */
-		SIN_TABLE[SIN_ENT / 2 + s] = SIN_TABLE[SIN_ENT - s] = &TL_TABLE[TL_MAX + j];
-	}
-	for (s = 0;s < SIN_ENT; s++) {
-		SIN_TABLE[SIN_ENT * 1 + s] = s < (SIN_ENT / 2) ? SIN_TABLE[s] : &TL_TABLE[EG_ENT];
-		SIN_TABLE[SIN_ENT * 2 + s] = SIN_TABLE[s % (SIN_ENT / 2)];
-		SIN_TABLE[SIN_ENT * 3 + s] = (s / (SIN_ENT / 4)) & 1 ? &TL_TABLE[EG_ENT] : SIN_TABLE[SIN_ENT * 2 + s];
-	}
-
-
-	ENV_CURVE = (int *)malloc(sizeof(int) * (2*EG_ENT+1));
-
-	/* envelope counter -> envelope output table */
-	for (i=0; i < EG_ENT; i++) {
-		/* ATTACK curve */
-		pom = pow(((double)(EG_ENT - 1 - i) / EG_ENT), 8) * EG_ENT;
-		/* if( pom >= EG_ENT ) pom = EG_ENT-1; */
-		ENV_CURVE[i] = (int)pom;
-		/* DECAY ,RELEASE curve */
-		ENV_CURVE[(EG_DST >> ENV_BITS) + i]= i;
-	}
-	/* off */
-	ENV_CURVE[EG_OFF >> ENV_BITS]= EG_ENT - 1;
-	/* make LFO ams table */
-	for (i=0; i < AMS_ENT; i++) {
-		pom = (1.0 + sin(2 * PI * i / AMS_ENT)) / 2; /* sin */
-		AMS_TABLE[i]         = (int)((1.0 / EG_STEP) * pom); /* 1dB   */
-		AMS_TABLE[AMS_ENT + i] = (int)((4.8 / EG_STEP) * pom); /* 4.8dB */
-	}
-	/* make LFO vibrate table */
-	for (i=0; i < VIB_ENT; i++) {
-		/* 100cent = 1seminote = 6% ?? */
-		pom = (double)VIB_RATE * 0.06 * sin(2 * PI * i / VIB_ENT); /* +-100sect step */
-		VIB_TABLE[i]         = (int)(VIB_RATE + (pom * 0.07)); /* +- 7cent */
-		VIB_TABLE[VIB_ENT + i] = (int)(VIB_RATE + (pom * 0.14)); /* +-14cent */
-	}
-	return 1;
-}
-
-static void OPLCloseTable(void) {
-	free(TL_TABLE);
-	free(SIN_TABLE);
-	free(AMS_TABLE);
-	free(VIB_TABLE);
-	free(ENV_CURVE);
-}
-
-/* CSM Key Controll */
-static inline void CSMKeyControll(OPL_CH *CH) {
-	OPL_SLOT *slot1 = &CH->SLOT[SLOT1];
-	OPL_SLOT *slot2 = &CH->SLOT[SLOT2];
-	/* all key off */
-	OPL_KEYOFF(slot1);
-	OPL_KEYOFF(slot2);
-	/* total level latch */
-	slot1->TLL = slot1->TL + (CH->ksl_base>>slot1->ksl);
-	slot1->TLL = slot1->TL + (CH->ksl_base>>slot1->ksl);
-	/* key on */
-	CH->op1_out[0] = CH->op1_out[1] = 0;
-	OPL_KEYON(slot1);
-	OPL_KEYON(slot2);
-}
-
-/* ---------- opl initialize ---------- */
-static void OPL_initalize(FM_OPL *OPL) {
-	int fn;
-
-	/* frequency base */
-	OPL->freqbase = (OPL->rate) ? ((double)OPL->clock / OPL->rate) / 72 : 0;
-	/* Timer base time */
-	OPL->TimerBase = 1.0/((double)OPL->clock / 72.0 );
-	/* make time tables */
-	init_timetables(OPL, OPL_ARRATE, OPL_DRRATE);
-	/* make fnumber -> increment counter table */
-	for( fn=0; fn < 1024; fn++) {
-		OPL->FN_TABLE[fn] = (uint32_t)(OPL->freqbase * fn * FREQ_RATE * (1<<7) / 2);
-	}
-	/* LFO freq.table */
-	OPL->amsIncr = (int)(OPL->rate ? (double)AMS_ENT * (1 << AMS_SHIFT) / OPL->rate * 3.7 * ((double)OPL->clock/3600000) : 0);
-	OPL->vibIncr = (int)(OPL->rate ? (double)VIB_ENT * (1 << VIB_SHIFT) / OPL->rate * 6.4 * ((double)OPL->clock/3600000) : 0);
-}
-
-/* ---------- write a OPL registers ---------- */
-void OPLWriteReg(FM_OPL *OPL, int r, int v) {
-	OPL_CH *CH;
-	int slot;
-	uint32_t block_fnum;
-
-	switch(r & 0xe0) {
-	case 0x00: /* 00-1f:controll */
-		switch(r & 0x1f) {
-		case 0x01:
-			/* wave selector enable */
-			if(OPL->type&OPL_TYPE_WAVESEL) {
-				OPL->wavesel = v & 0x20;
-				if(!OPL->wavesel) {
-					/* preset compatible mode */
-					int c;
-					for(c=0; c<OPL->max_ch; c++) {
-						OPL->P_CH[c].SLOT[SLOT1].wavetable = &SIN_TABLE[0];
-						OPL->P_CH[c].SLOT[SLOT2].wavetable = &SIN_TABLE[0];
-					}
-				}
-			}
-			return;
-		case 0x02:	/* Timer 1 */
-			OPL->T[0] = (256-v) * 4;
-			break;
-		case 0x03:	/* Timer 2 */
-			OPL->T[1] = (256-v) * 16;
-			return;
-		case 0x04:	/* IRQ clear / mask and Timer enable */
-			if(v & 0x80) {	/* IRQ flag clear */
-				OPL_STATUS_RESET(OPL, 0x7f);
-			} else {	/* set IRQ mask ,timer enable*/
-				uint8_t st1 = v & 1;
-				uint8_t st2 = (v >> 1) & 1;
-				/* IRQRST,T1MSK,t2MSK,EOSMSK,BRMSK,x,ST2,ST1 */
-				OPL_STATUS_RESET(OPL, v & 0x78);
-				OPL_STATUSMASK_SET(OPL,((~v) & 0x78) | 0x01);
-				/* timer 2 */
-				if(OPL->st[1] != st2) {
-					double interval = st2 ? (double)OPL->T[1] * OPL->TimerBase : 0.0;
-					OPL->st[1] = st2;
-					if (OPL->TimerHandler) (OPL->TimerHandler)(OPL->TimerParam + 1, interval);
-				}
-				/* timer 1 */
-				if(OPL->st[0] != st1) {
-					double interval = st1 ? (double)OPL->T[0] * OPL->TimerBase : 0.0;
-					OPL->st[0] = st1;
-					if (OPL->TimerHandler) (OPL->TimerHandler)(OPL->TimerParam + 0, interval);
-				}
-			}
-			return;
-		}
-		break;
-	case 0x20:	/* am,vib,ksr,eg type,mul */
-		slot = slot_array[r&0x1f];
-		if(slot == -1)
-			return;
-		set_mul(OPL,slot,v);
-		return;
-	case 0x40:
-		slot = slot_array[r&0x1f];
-		if(slot == -1)
-			return;
-		set_ksl_tl(OPL,slot,v);
-		return;
-	case 0x60:
-		slot = slot_array[r&0x1f];
-		if(slot == -1)
-			return;
-		set_ar_dr(OPL,slot,v);
-		return;
-	case 0x80:
-		slot = slot_array[r&0x1f];
-		if(slot == -1)
-			return;
-		set_sl_rr(OPL,slot,v);
-		return;
-	case 0xa0:
-		switch(r) {
-		case 0xbd:
-			/* amsep,vibdep,r,bd,sd,tom,tc,hh */
-			{
-			uint8_t rkey = OPL->rythm ^ v;
-			OPL->ams_table = &AMS_TABLE[v & 0x80 ? AMS_ENT : 0];
-			OPL->vib_table = &VIB_TABLE[v & 0x40 ? VIB_ENT : 0];
-			OPL->rythm  = v & 0x3f;
-			if(OPL->rythm & 0x20) {
-				/* BD key on/off */
-				if(rkey & 0x10) {
-					if(v & 0x10) {
-						OPL->P_CH[6].op1_out[0] = OPL->P_CH[6].op1_out[1] = 0;
-						OPL_KEYON(&OPL->P_CH[6].SLOT[SLOT1]);
-						OPL_KEYON(&OPL->P_CH[6].SLOT[SLOT2]);
-					} else {
-						OPL_KEYOFF(&OPL->P_CH[6].SLOT[SLOT1]);
-						OPL_KEYOFF(&OPL->P_CH[6].SLOT[SLOT2]);
-					}
-				}
-				/* SD key on/off */
-				if(rkey & 0x08) {
-					if(v & 0x08)
-						OPL_KEYON(&OPL->P_CH[7].SLOT[SLOT2]);
-					else
-						OPL_KEYOFF(&OPL->P_CH[7].SLOT[SLOT2]);
-				}/* TAM key on/off */
-				if(rkey & 0x04) {
-					if(v & 0x04)
-						OPL_KEYON(&OPL->P_CH[8].SLOT[SLOT1]);
-					else
-						OPL_KEYOFF(&OPL->P_CH[8].SLOT[SLOT1]);
-				}
-				/* TOP-CY key on/off */
-				if(rkey & 0x02) {
-					if(v & 0x02)
-						OPL_KEYON(&OPL->P_CH[8].SLOT[SLOT2]);
-					else
-						OPL_KEYOFF(&OPL->P_CH[8].SLOT[SLOT2]);
-				}
-				/* HH key on/off */
-				if(rkey & 0x01) {
-					if(v & 0x01)
-						OPL_KEYON(&OPL->P_CH[7].SLOT[SLOT1]);
-					else
-						OPL_KEYOFF(&OPL->P_CH[7].SLOT[SLOT1]);
-				}
-			}
-			}
-			return;
-
-		default:
-			break;
-		}
-		/* keyon,block,fnum */
-		if((r & 0x0f) > 8)
-			return;
-		CH = &OPL->P_CH[r & 0x0f];
-		if(!(r&0x10)) {	/* a0-a8 */
-			block_fnum  = (CH->block_fnum & 0x1f00) | v;
-		} else {	/* b0-b8 */
-			int keyon = (v >> 5) & 1;
-			block_fnum = ((v & 0x1f) << 8) | (CH->block_fnum & 0xff);
-			if(CH->keyon != keyon) {
-				if((CH->keyon=keyon)) {
-					CH->op1_out[0] = CH->op1_out[1] = 0;
-					OPL_KEYON(&CH->SLOT[SLOT1]);
-					OPL_KEYON(&CH->SLOT[SLOT2]);
-				} else {
-					OPL_KEYOFF(&CH->SLOT[SLOT1]);
-					OPL_KEYOFF(&CH->SLOT[SLOT2]);
-				}
-			}
-		}
-		/* update */
-		if(CH->block_fnum != block_fnum) {
-			int blockRv = 7 - (block_fnum >> 10);
-			int fnum = block_fnum & 0x3ff;
-			CH->block_fnum = block_fnum;
-			CH->ksl_base = KSL_TABLE[block_fnum >> 6];
-			CH->fc = OPL->FN_TABLE[fnum] >> blockRv;
-			CH->kcode = CH->block_fnum >> 9;
-			if((OPL->mode & 0x40) && CH->block_fnum & 0x100)
-				CH->kcode |=1;
-			CALC_FCSLOT(CH,&CH->SLOT[SLOT1]);
-			CALC_FCSLOT(CH,&CH->SLOT[SLOT2]);
-		}
-		return;
-	case 0xc0:
-		/* FB,C */
-		if((r & 0x0f) > 8)
-			return;
-		CH = &OPL->P_CH[r&0x0f];
-		{
-			int feedback = (v >> 1) & 7;
-			CH->FB = feedback ? (8 + 1) - feedback : 0;
-			CH->CON = v & 1;
-			set_algorythm(CH);
-		}
-		return;
-	case 0xe0: /* wave type */
-		slot = slot_array[r & 0x1f];
-		if(slot == -1)
-			return;
-		CH = &OPL->P_CH[slot>>1];
-		if(OPL->wavesel) {
-			CH->SLOT[slot&1].wavetable = &SIN_TABLE[(v & 0x03) * SIN_ENT];
-		}
-		return;
-	}
-}
-
-/* lock/unlock for common table */
-static int OPL_LockTable(void) {
-	num_lock++;
-	if(num_lock>1)
-		return 0;
-	/* first time */
-	cur_chip = NULL;
-	/* allocate total level table (128kb space) */
-	if(!OPLOpenTable()) {
-		num_lock--;
-		return -1;
-	}
-	return 0;
-}
-
-static void OPL_UnLockTable(void) {
-	if(num_lock)
-		num_lock--;
-	if(num_lock)
-		return;
-	/* last time */
-	cur_chip = NULL;
-	OPLCloseTable();
-}
-
-/*******************************************************************************/
-/*		YM3812 local section                                                   */
-/*******************************************************************************/
-
-/* ---------- update one of chip ----------- */
-void YM3812UpdateOne(FM_OPL *OPL, int16_t *buffer, int length, int interleave) {
-	int i;
-	int data;
-	int16_t *buf = buffer;
-	uint32_t amsCnt = OPL->amsCnt;
-	uint32_t vibCnt = OPL->vibCnt;
-	uint8_t rythm = OPL->rythm & 0x20;
-	OPL_CH *CH, *R_CH;
-
-
-	if((void *)OPL != cur_chip) {
-		cur_chip = (void *)OPL;
-		/* channel pointers */
-		S_CH = OPL->P_CH;
-		E_CH = &S_CH[9];
-		/* rythm slot */
-		SLOT7_1 = &S_CH[7].SLOT[SLOT1];
-		SLOT7_2 = &S_CH[7].SLOT[SLOT2];
-		SLOT8_1 = &S_CH[8].SLOT[SLOT1];
-		SLOT8_2 = &S_CH[8].SLOT[SLOT2];
-		/* LFO state */
-		amsIncr = OPL->amsIncr;
-		vibIncr = OPL->vibIncr;
-		ams_table = OPL->ams_table;
-		vib_table = OPL->vib_table;
-	}
-	R_CH = rythm ? &S_CH[6] : E_CH;
-	for(i = 0; i < length; i++) {
-		/*            channel A         channel B         channel C      */
-		/* LFO */
-		ams = ams_table[(amsCnt += amsIncr) >> AMS_SHIFT];
-		vib = vib_table[(vibCnt += vibIncr) >> VIB_SHIFT];
-		outd[0] = 0;
-		/* FM part */
-		for(CH=S_CH; CH < R_CH; CH++)
-			OPL_CALC_CH(CH);
-		/* Rythn part */
-		if(rythm)
-			OPL_CALC_RH(OPL, S_CH);
-		/* limit check */
-		data = CLIP(outd[0], OPL_MINOUT, OPL_MAXOUT);
-		/* store to sound buffer */
-		buf[i << interleave] = data >> OPL_OUTSB;
-	}
-
-	OPL->amsCnt = amsCnt;
-	OPL->vibCnt = vibCnt;
-}
-
-/* ---------- reset a chip ---------- */
-void OPLResetChip(FM_OPL *OPL) {
-	int c,s;
-	int i;
-
-	/* reset chip */
-	OPL->mode = 0;	/* normal mode */
-	OPL_STATUS_RESET(OPL, 0x7f);
-	/* reset with register write */
-	OPLWriteReg(OPL, 0x01,0); /* wabesel disable */
-	OPLWriteReg(OPL, 0x02,0); /* Timer1 */
-	OPLWriteReg(OPL, 0x03,0); /* Timer2 */
-	OPLWriteReg(OPL, 0x04,0); /* IRQ mask clear */
-	for(i = 0xff; i >= 0x20; i--)
-		OPLWriteReg(OPL,i,0);
-	/* reset OPerator parameter */
-	for(c = 0; c < OPL->max_ch ;c++ ) {
-		OPL_CH *CH = &OPL->P_CH[c];
-		/* OPL->P_CH[c].PAN = OPN_CENTER; */
-		for(s = 0; s < 2; s++ ) {
-			/* wave table */
-			CH->SLOT[s].wavetable = &SIN_TABLE[0];
-			/* CH->SLOT[s].evm = ENV_MOD_RR; */
-			CH->SLOT[s].evc = EG_OFF;
-			CH->SLOT[s].eve = EG_OFF + 1;
-			CH->SLOT[s].evs = 0;
-		}
-	}
-}
-
-/* ----------  Create a virtual YM3812 ----------       */
-/* 'rate'  is sampling rate and 'bufsiz' is the size of the  */
-FM_OPL *OPLCreate(int type, int clock, int rate) {
-	char *ptr;
-	FM_OPL *OPL;
-	int state_size;
-	int max_ch = 9; /* normaly 9 channels */
-
-	if( OPL_LockTable() == -1)
-		return NULL;
-	/* allocate OPL state space */
-	state_size  = sizeof(FM_OPL);
-	state_size += sizeof(OPL_CH) * max_ch;
-
-	/* allocate memory block */
-	ptr = (char *)calloc(state_size, 1);
-	if(ptr == NULL)
-		return NULL;
-
-	/* clear */
-	memset(ptr, 0, state_size);
-	OPL       = (FM_OPL *)ptr; ptr += sizeof(FM_OPL);
-	OPL->P_CH = (OPL_CH *)ptr; ptr += sizeof(OPL_CH) * max_ch;
-
-	/* set channel state pointer */
-	OPL->type  = type;
-	OPL->clock = clock;
-	OPL->rate  = rate;
-	OPL->max_ch = max_ch;
-
-	/* init grobal tables */
-	OPL_initalize(OPL);
-
-	/* reset chip */
-	OPLResetChip(OPL);
-	return OPL;
-}
-
-/* ----------  Destroy one of vietual YM3812 ----------       */
-void OPLDestroy(FM_OPL *OPL) {
-	OPL_UnLockTable();
-	free(OPL);
-}
-
-/* ----------  Option handlers ----------       */
-void OPLSetTimerHandler(FM_OPL *OPL, OPL_TIMERHANDLER TimerHandler,int channelOffset) {
-	OPL->TimerHandler   = TimerHandler;
-	OPL->TimerParam = channelOffset;
-}
-
-void OPLSetIRQHandler(FM_OPL *OPL, OPL_IRQHANDLER IRQHandler, int param) {
-	OPL->IRQHandler     = IRQHandler;
-	OPL->IRQParam = param;
-}
-
-void OPLSetUpdateHandler(FM_OPL *OPL, OPL_UPDATEHANDLER UpdateHandler,int param) {
-	OPL->UpdateHandler = UpdateHandler;
-	OPL->UpdateParam = param;
-}
-
-/* ---------- YM3812 I/O interface ---------- */
-int OPLWrite(FM_OPL *OPL,int a,int v) {
-	if(!(a & 1)) {	/* address port */
-		OPL->address = v & 0xff;
-	} else {	/* data port */
-		if(OPL->UpdateHandler)
-			OPL->UpdateHandler(OPL->UpdateParam,0);
-		OPLWriteReg(OPL, OPL->address,v);
-	}
-	return OPL->status >> 7;
-}
-
-unsigned char OPLRead(FM_OPL *OPL,int a) {
-	if(!(a & 1)) {	/* status port */
-		return OPL->status & (OPL->statusmask | 0x80);
-	}
-
-	return 0;
-}
-
-int OPLTimerOver(FM_OPL *OPL, int c) {
-	if(c) {	/* Timer B */
-		OPL_STATUS_SET(OPL, 0x20);
-	} else {	/* Timer A */
-		OPL_STATUS_SET(OPL, 0x40);
-		/* CSM mode key,TL controll */
-		if(OPL->mode & 0x80) {	/* CSM mode total level latch and auto key on */
-			int ch;
-			if(OPL->UpdateHandler)
-				OPL->UpdateHandler(OPL->UpdateParam,0);
-			for(ch = 0; ch < 9; ch++)
-				CSMKeyControll(&OPL->P_CH[ch]);
-		}
-	}
-	/* reload timer */
-	if (OPL->TimerHandler)
-		(OPL->TimerHandler)(OPL->TimerParam + c, (double)OPL->T[c] * OPL->TimerBase);
-	return OPL->status >> 7;
-}
-
-FM_OPL *makeAdlibOPL(int rate) {
-	// We need to emulate one YM3812 chip
-	int env_bits = FMOPL_ENV_BITS_HQ;
-	int eg_ent = FMOPL_EG_ENT_HQ;
-
-	OPLBuildTables(env_bits, eg_ent);
-	return OPLCreate(OPL_TYPE_YM3812, 3579545, rate);
-}
-
diff --git a/opl/fmopl.h b/opl/fmopl.h
deleted file mode 100644
index 2bbe8363..00000000
--- a/opl/fmopl.h
+++ /dev/null
@@ -1,167 +0,0 @@
-/* This file is derived from fmopl.h from ScummVM.
- *
- * 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.
- *
- * LGPL licensed version of MAMEs fmopl (V0.37a modified) by
- * Tatsuyuki Satoh. Included from LGPL'ed AdPlug.
- */
-
-
-#ifndef OPL_FMOPL_H
-#define OPL_FMOPL_H
-
-#include "inttypes.h"
-
-enum {
-	FMOPL_ENV_BITS_HQ = 16,
-	FMOPL_ENV_BITS_MQ = 8,
-	FMOPL_ENV_BITS_LQ = 8,
-	FMOPL_EG_ENT_HQ = 4096,
-	FMOPL_EG_ENT_MQ = 1024,
-	FMOPL_EG_ENT_LQ = 128
-};
-
-typedef void (*OPL_TIMERHANDLER)(int channel,double interval_Sec);
-typedef void (*OPL_IRQHANDLER)(int param,int irq);
-typedef void (*OPL_UPDATEHANDLER)(int param,int min_interval_us);
-
-#define OPL_TYPE_WAVESEL   0x01  /* waveform select    */
-
-/* Saving is necessary for member of the 'R' mark for suspend/resume */
-/* ---------- OPL one of slot  ---------- */
-typedef struct fm_opl_slot {
-	int TL;		/* total level     :TL << 8				*/
-	int TLL;	/* adjusted now TL						*/
-	uint8_t KSR;	/* key scale rate  :(shift down bit)	*/
-	int *AR;	/* attack rate     :&AR_TABLE[AR<<2]	*/
-	int *DR;	/* decay rate      :&DR_TABLE[DR<<2]	*/
-	int SL;		/* sustain level   :SL_TABLE[SL]		*/
-	int *RR;	/* release rate    :&DR_TABLE[RR<<2]	*/
-	uint8_t ksl;	/* keyscale level  :(shift down bits)	*/
-	uint8_t ksr;	/* key scale rate  :kcode>>KSR			*/
-	unsigned int mul;	/* multiple        :ML_TABLE[ML]		*/
-	unsigned int Cnt;	/* frequency count						*/
-	unsigned int Incr;	/* frequency step						*/
-
-	/* envelope generator state */
-	uint8_t eg_typ;/* envelope type flag					*/
-	uint8_t evm;	/* envelope phase						*/
-	int evc;	/* envelope counter						*/
-	int eve;	/* envelope counter end point			*/
-	int evs;	/* envelope counter step				*/
-	int evsa;	/* envelope step for AR :AR[ksr]		*/
-	int evsd;	/* envelope step for DR :DR[ksr]		*/
-	int evsr;	/* envelope step for RR :RR[ksr]		*/
-
-	/* LFO */
-	uint8_t ams;		/* ams flag                            */
-	uint8_t vib;		/* vibrate flag                        */
-	/* wave selector */
-	int **wavetable;
-} OPL_SLOT;
-
-/* ---------- OPL one of channel  ---------- */
-typedef struct fm_opl_channel {
-	OPL_SLOT SLOT[2];
-	uint8_t CON;			/* connection type					*/
-	uint8_t FB;			/* feed back       :(shift down bit)*/
-	int *connect1;		/* slot1 output pointer				*/
-	int *connect2;		/* slot2 output pointer				*/
-	int op1_out[2];		/* slot1 output for selfeedback		*/
-
-	/* phase generator state */
-	unsigned int block_fnum;	/* block+fnum						*/
-	uint8_t kcode;		/* key code        : KeyScaleCode	*/
-	unsigned int fc;			/* Freq. Increment base				*/
-	unsigned int ksl_base;		/* KeyScaleLevel Base step			*/
-	uint8_t keyon;		/* key on/off flag					*/
-} OPL_CH;
-
-/* OPL state */
-typedef struct fm_opl_f {
-	uint8_t type;			/* chip type                         */
-	int clock;			/* master clock  (Hz)                */
-	int rate;			/* sampling rate (Hz)                */
-	double freqbase;	/* frequency base                    */
-	double TimerBase;	/* Timer base time (==sampling time) */
-	uint8_t address;		/* address register                  */
-	uint8_t status;		/* status flag                       */
-	uint8_t statusmask;	/* status mask                       */
-	unsigned int mode;			/* Reg.08 : CSM , notesel,etc.       */
-
-	/* Timer */
-	int T[2];			/* timer counter                     */
-	uint8_t st[2];		/* timer enable                      */
-
-	/* FM channel slots */
-	OPL_CH *P_CH;		/* pointer of CH                     */
-	int	max_ch;			/* maximum channel                   */
-
-	/* Rythm sention */
-	uint8_t rythm;		/* Rythm mode , key flag */
-
-	/* time tables */
-	int AR_TABLE[76];	/* atttack rate tables				*/
-	int DR_TABLE[76];	/* decay rate tables				*/
-	unsigned int FN_TABLE[1024];/* fnumber -> increment counter		*/
-
-	/* LFO */
-	int *ams_table;
-	int *vib_table;
-	int amsCnt;
-	int amsIncr;
-	int vibCnt;
-	int vibIncr;
-
-	/* wave selector enable flag */
-	uint8_t wavesel;
-
-	/* external event callback handler */
-	OPL_TIMERHANDLER  TimerHandler;		/* TIMER handler   */
-	int TimerParam;						/* TIMER parameter */
-	OPL_IRQHANDLER    IRQHandler;		/* IRQ handler    */
-	int IRQParam;						/* IRQ parameter  */
-	OPL_UPDATEHANDLER UpdateHandler;	/* stream update handler   */
-	int UpdateParam;					/* stream update parameter */
-} FM_OPL;
-
-/* ---------- Generic interface section ---------- */
-#define OPL_TYPE_YM3526 (0)
-#define OPL_TYPE_YM3812 (OPL_TYPE_WAVESEL)
-
-void OPLBuildTables(int ENV_BITS_PARAM, int EG_ENT_PARAM);
-
-FM_OPL *OPLCreate(int type, int clock, int rate);
-void OPLDestroy(FM_OPL *OPL);
-void OPLSetTimerHandler(FM_OPL *OPL, OPL_TIMERHANDLER TimerHandler, int channelOffset);
-void OPLSetIRQHandler(FM_OPL *OPL, OPL_IRQHANDLER IRQHandler, int param);
-void OPLSetUpdateHandler(FM_OPL *OPL, OPL_UPDATEHANDLER UpdateHandler, int param);
-
-void OPLResetChip(FM_OPL *OPL);
-int OPLWrite(FM_OPL *OPL, int a, int v);
-unsigned char OPLRead(FM_OPL *OPL, int a);
-int OPLTimerOver(FM_OPL *OPL, int c);
-void OPLWriteReg(FM_OPL *OPL, int r, int v);
-void YM3812UpdateOne(FM_OPL *OPL, int16_t *buffer, int length, int interleave);
-
-// Factory method
-FM_OPL *makeAdlibOPL(int rate);
-
-#endif
-
diff --git a/opl/opl_sdl.c b/opl/opl_sdl.c
index 1963d5cd..8b7d76e5 100644
--- a/opl/opl_sdl.c
+++ b/opl/opl_sdl.c
@@ -33,7 +33,7 @@
 #include "SDL.h"
 #include "SDL_mixer.h"
 
-#include "fmopl.h"
+#include "dbopl.h"
 
 #include "opl.h"
 #include "opl_internal.h"
@@ -42,6 +42,14 @@
 
 #define MAX_SOUND_SLICE_TIME 100 /* ms */
 
+typedef struct
+{
+    unsigned int rate;        // Number of times the timer is advanced per sec.
+    unsigned int enabled;     // Non-zero if timer is enabled.
+    unsigned int value;       // Last value that was set.
+    unsigned int expire_time; // Calculated time that timer will expire.
+} opl_timer_t;
+
 // When the callback mutex is locked using OPL_Lock, callback functions
 // are not invoked.
 
@@ -70,11 +78,20 @@ static unsigned int pause_offset;
 
 // OPL software emulator structure.
 
-static FM_OPL *opl_emulator = NULL;
+static Chip opl_chip;
 
 // Temporary mixing buffer used by the mixing callback.
 
-static int16_t *mix_buffer = NULL;
+static int32_t *mix_buffer = NULL;
+
+// Register number that was written.
+
+static int register_num = 0;
+
+// Timers; DBOPL does not do timer stuff itself.
+
+static opl_timer_t timer1 = { 12500, 0, 0, 0 };
+static opl_timer_t timer2 = { 3125, 0, 0, 0 };
 
 // SDL parameters.
 
@@ -153,14 +170,14 @@ static void FillBuffer(int16_t *buffer, unsigned int nsamples)
 
     assert(nsamples < mixing_freq);
 
-    YM3812UpdateOne(opl_emulator, mix_buffer, nsamples, 0);
+    Chip__GenerateBlock2(&opl_chip, nsamples, mix_buffer);
 
     // Mix into the destination buffer, doubling up into stereo.
 
     for (i=0; i<nsamples; ++i)
     {
-        buffer[i * 2] = mix_buffer[i];
-        buffer[i * 2 + 1] = mix_buffer[i];
+        buffer[i * 2] = (int16_t) (mix_buffer[i] / 65536);
+        buffer[i * 2 + 1] = (int16_t) (mix_buffer[i] / 65536);
     }
 }
 
@@ -179,7 +196,7 @@ static void OPL_Mix_Callback(void *udata,
     buffer = (int16_t *) byte_buffer;
     buffer_len = buffer_bytes / 4;
 
-    // Repeatedly call the FMOPL update function until the buffer is
+    // Repeatedly call the OPL emulator update function until the buffer is
     // full.
 
     while (filled < buffer_len)
@@ -235,11 +252,13 @@ static void OPL_SDL_Shutdown(void)
         sdl_was_initialized = 0;
     }
 
-    if (opl_emulator != NULL)
+/*
+    if (opl_chip != NULL)
     {
-        OPLDestroy(opl_emulator);
-        opl_emulator = NULL;
+        OPLDestroy(opl_chip);
+        opl_chip = NULL;
     }
+    */
 
     if (callback_mutex != NULL)
     {
@@ -254,29 +273,6 @@ static void OPL_SDL_Shutdown(void)
     }
 }
 
-// Callback when a timer expires.
-
-static void TimerOver(void *data)
-{
-    int channel = (int) data;
-
-    OPLTimerOver(opl_emulator, channel);
-}
-
-// Callback invoked when the emulator code wants to set a timer.
-
-static void TimerHandler(int channel, double interval_seconds)
-{
-    unsigned int interval_samples;
-
-    interval_samples = (int) (interval_seconds * mixing_freq);
-
-    SDL_LockMutex(callback_queue_mutex);
-    OPL_Queue_Push(callback_queue, TimerOver, (void *) channel,
-                   current_time - pause_offset + interval_samples);
-    SDL_UnlockMutex(callback_queue_mutex);
-}
-
 static unsigned int GetSliceSize(void)
 {
     int limit;
@@ -360,20 +356,13 @@ static int OPL_SDL_Init(unsigned int port_base)
 
     // Mix buffer:
 
-    mix_buffer = malloc(mixing_freq * 2);
+    mix_buffer = malloc(mixing_freq * sizeof(uint32_t));
 
     // Create the emulator structure:
 
-    opl_emulator = makeAdlibOPL(mixing_freq);
-
-    if (opl_emulator == NULL)
-    {
-        fprintf(stderr, "Failed to initialize software OPL emulator!\n");
-        OPL_SDL_Shutdown();
-        return 0;
-    }
-
-    OPLSetTimerHandler(opl_emulator, TimerHandler, 0);
+    DBOPL_InitTables();
+    Chip__Chip(&opl_chip);
+    Chip__Setup(&opl_chip, mixing_freq);
 
     callback_mutex = SDL_CreateMutex();
     callback_queue_mutex = SDL_CreateMutex();
@@ -386,21 +375,90 @@ static int OPL_SDL_Init(unsigned int port_base)
 
 static unsigned int OPL_SDL_PortRead(opl_port_t port)
 {
-    if (opl_emulator != NULL)
+    unsigned int result = 0;
+
+    if (timer1.enabled && current_time > timer1.expire_time)
     {
-        return OPLRead(opl_emulator, port);
+        result |= 0x80;   // Either have expired
+        result |= 0x40;   // Timer 1 has expired
     }
-    else
+
+    if (timer2.enabled && current_time > timer2.expire_time)
     {
-        return 0;
+        result |= 0x80;   // Either have expired
+        result |= 0x20;   // Timer 2 has expired
+    }
+
+    return result;
+}
+
+static void OPLTimer_CalculateEndTime(opl_timer_t *timer)
+{
+    int tics;
+
+    // If the timer is enabled, calculate the time when the timer
+    // will expire.
+
+    if (timer->enabled)
+    {
+        tics = 0x100 - timer->value;
+        timer->expire_time = current_time
+                           + (tics * opl_sample_rate) / timer->rate;
+    }
+}
+
+static void WriteRegister(unsigned int reg_num, unsigned int value)
+{
+    switch (reg_num)
+    {
+        case OPL_REG_TIMER1:
+            timer1.value = value;
+            OPLTimer_CalculateEndTime(&timer1);
+            break;
+
+        case OPL_REG_TIMER2:
+            timer2.value = value;
+            OPLTimer_CalculateEndTime(&timer2);
+            break;
+
+        case OPL_REG_TIMER_CTRL:
+            if (value & 0x80)
+            {
+                timer1.enabled = 0;
+                timer2.enabled = 0;
+            }
+            else
+            {
+                if ((value & 0x40) == 0)
+                {
+                    timer1.enabled = (value & 0x01) != 0;
+                    OPLTimer_CalculateEndTime(&timer1);
+                }
+
+                if ((value & 0x20) == 0)
+                {
+                    timer1.enabled = (value & 0x02) != 0;
+                    OPLTimer_CalculateEndTime(&timer2);
+                }
+            }
+
+            break;
+
+        default:
+            Chip__WriteReg(&opl_chip, reg_num, value);
+            break;
     }
 }
 
 static void OPL_SDL_PortWrite(opl_port_t port, unsigned int value)
 {
-    if (opl_emulator != NULL)
+    if (port == OPL_REGISTER_PORT)
+    {
+        register_num = value;
+    }
+    else if (port == OPL_DATA_PORT)
     {
-        OPLWrite(opl_emulator, port, value);
+        WriteRegister(register_num, value);
     }
 }