text: /*
  **
  ** File: ym2413.c - software implementation of YM2413
  **                  FM sound generator type OPLL
  **
  ** Copyright (C) 2002 Jarek Burczynski
  **
  ** Version 1.0
  **
  
  
  to do:
  
  - make sure of the sinus amplitude bits
  
  - make sure of the EG resolution bits (looks like the biggest
    modulation index generated by the modulator is 123, 124 = no modulation)
  - find proper algorithm for attack phase of EG
  
  - tune up instruments ROM
  
  - support sample replay in test mode (it is NOT as simple as setting bit 0
    in register 0x0f and using register 0x10 for sample data).
    Which games use this feature ?
  
  
  */
  
  #include <stdio.h>
  #include <stdlib.h>
  #include <math.h>
  
  #include "driver.h"		/* use M.A.M.E. */
  #include "ym2413.h"
  
  #ifndef PI
  #define PI 3.14159265358979323846
  #endif
  
  
  
  /* output final shift */
  #define FINAL_SH	(0)
  #define MAXOUT		(+32767)
  #define MINOUT		(-32768)
  
  
  #define FREQ_SH			16  /* 16.16 fixed point (frequency calculations) */
  #define EG_SH			16  /* 16.16 fixed point (EG timing)              */
  #define LFO_SH			24  /*  8.24 fixed point (LFO calculations)       */
  
  #define FREQ_MASK		((1<<FREQ_SH)-1)
  
  /* envelope output entries */
  #define ENV_BITS		10
  #define ENV_LEN			(1<<ENV_BITS)
  #define ENV_STEP		(128.0/ENV_LEN)
  
  #define MAX_ATT_INDEX	((1<<(ENV_BITS-2))-1) /*255*/
  #define MIN_ATT_INDEX	(0)
  
  /* sinwave entries */
  #define SIN_BITS		10
  #define SIN_LEN			(1<<SIN_BITS)
  #define SIN_MASK		(SIN_LEN-1)
  
  #define TL_RES_LEN		(256)	/* 8 bits addressing (real chip) */
  
  
  
  /* register number to channel number , slot offset */
  #define SLOT1 0
  #define SLOT2 1
  
  /* Envelope Generator phases */
  
  #define EG_DMP			5
  #define EG_ATT			4
  #define EG_DEC			3
  #define EG_SUS			2
  #define EG_REL			1
  #define EG_OFF			0
  
  
  /* save output as raw 16-bit sample */
  
  /*#define SAVE_SAMPLE*/
  
  #ifdef SAVE_SAMPLE
  static INLINE signed int acc_calc(signed int value)
  {
  	if (value>=0)
  	{
  		if (value < 0x0200)
  			return (value & ~0);
  		if (value < 0x0400)
  			return (value & ~1);
  		if (value < 0x0800)
  			return (value & ~3);
  		if (value < 0x1000)
  			return (value & ~7);
  		if (value < 0x2000)
  			return (value & ~15);
  		if (value < 0x4000)
  			return (value & ~31);
  		return (value & ~63);
  	}
  	/*else value < 0*/
  	if (value > -0x0200)
  		return (~abs(value) & ~0);
  	if (value > -0x0400)
  		return (~abs(value) & ~1);
  	if (value > -0x0800)
  		return (~abs(value) & ~3);
  	if (value > -0x1000)
  		return (~abs(value) & ~7);
  	if (value > -0x2000)
  		return (~abs(value) & ~15);
  	if (value > -0x4000)
  		return (~abs(value) & ~31);
  	return (~abs(value) & ~63);
  }
  
  
  static FILE *sample[1];
  	#if 0	/*save to MONO file */
  		#define SAVE_ALL_CHANNELS \
  		{	signed int pom = acc_calc(mo); \
  			fputc((unsigned short)pom&0xff,sample[0]); \
  			fputc(((unsigned short)pom>>8)&0xff,sample[0]); \
  		}
  	#else	/*save to STEREO file */
  		#define SAVE_ALL_CHANNELS \
  		{	signed int pom = mo; \
  			fputc((unsigned short)pom&0xff,sample[0]); \
  			fputc(((unsigned short)pom>>8)&0xff,sample[0]); \
  			pom = ro; \
  			fputc((unsigned short)pom&0xff,sample[0]); \
  			fputc(((unsigned short)pom>>8)&0xff,sample[0]); \
  		}
  		#define SAVE_SEPARATE_CHANNEL(j) \
  		{	signed int pom = outchan; \
  			fputc((unsigned short)pom&0xff,sample[0]); \
  			fputc(((unsigned short)pom>>8)&0xff,sample[0]); \
  			pom = chip->instvol_r[j]>>4; \
  			fputc((unsigned short)pom&0xff,sample[0]); \
  			fputc(((unsigned short)pom>>8)&0xff,sample[0]); \
  		}
  	#endif
  #endif
  
  /*#define LOG_CYM_FILE*/
  #ifdef LOG_CYM_FILE
  	FILE * cymfile = NULL;
  #endif
  
  
  
  
  typedef struct{
  	UINT32	ar;			/* attack rate: AR<<2			*/
  	UINT32	dr;			/* decay rate:  DR<<2			*/
  	UINT32	rr;			/* release rate:RR<<2			*/
  	UINT8	KSR;		/* key scale rate				*/
  	UINT8	ksl;		/* keyscale level				*/
  	UINT8	ksr;		/* key scale rate: kcode>>KSR	*/
  	UINT8	mul;		/* multiple: mul_tab[ML]		*/
  
  	/* Phase Generator */
  	UINT32	phase;		/* frequency counter			*/
  	UINT32	freq;		/* frequency counter step		*/
  	UINT8   fb_shift;	/* feedback shift value			*/
  	INT32   op1_out[2];	/* slot1 output for feedback	*/
  
  	/* Envelope Generator */
  	UINT8	eg_type;	/* percussive/nonpercussive mode*/
  	UINT8	state;		/* phase type					*/
  	UINT32	TL;			/* total level: TL << 2			*/
  	INT32	TLL;		/* adjusted now TL				*/
  	INT32	volume;		/* envelope counter				*/
  	UINT32	sl;			/* sustain level: sl_tab[SL]	*/
  
  	UINT8	eg_sh_dp;	/* (dump state)					*/
  	UINT8	eg_sel_dp;	/* (dump state)					*/
  	UINT8	eg_sh_ar;	/* (attack state)				*/
  	UINT8	eg_sel_ar;	/* (attack state)				*/
  	UINT8	eg_sh_dr;	/* (decay state)				*/
  	UINT8	eg_sel_dr;	/* (decay state)				*/
  	UINT8	eg_sh_rr;	/* (release state for non-perc.)*/
  	UINT8	eg_sel_rr;	/* (release state for non-perc.)*/
  	UINT8	eg_sh_rs;	/* (release state for perc.mode)*/
  	UINT8	eg_sel_rs;	/* (release state for perc.mode)*/
  
  	UINT32	key;		/* 0 = KEY OFF, >0 = KEY ON		*/
  
  	/* LFO */
  	UINT32	AMmask;		/* LFO Amplitude Modulation enable mask */
  	UINT8	vib;		/* LFO Phase Modulation enable flag (active high)*/
  
  	/* waveform select */
  	unsigned int wavetable;
  } OPLL_SLOT;
  
  typedef struct{
  	OPLL_SLOT SLOT[2];
  	/* phase generator state */
  	UINT32  block_fnum;	/* block+fnum					*/
  	UINT32  fc;			/* Freq. freqement base			*/
  	UINT32  ksl_base;	/* KeyScaleLevel Base step		*/
  	UINT8   kcode;		/* key code (for key scaling)	*/
  	UINT8   sus;		/* sus on/off (release speed in percussive mode)*/
  } OPLL_CH;
  
  /* chip state */
  typedef struct {
  	OPLL_CH	P_CH[9];				/* OPLL chips have 9 channels*/
  	UINT8	instvol_r[9];			/* instrument/volume (or volume/volume in percussive mode)*/
  
  	UINT32	eg_cnt;					/* global envelope generator counter	*/
  	UINT32	eg_timer;				/* global envelope generator counter works at frequency = chipclock/72 */
  	UINT32	eg_timer_add;			/* step of eg_timer						*/
  	UINT32	eg_timer_overflow;		/* envelope generator timer overlfows every 1 sample (on real chip) */
  
  	UINT8	rhythm;					/* Rhythm mode					*/
  
  	/* LFO */
  	UINT32	lfo_am_cnt;
  	UINT32	lfo_am_inc;
  	UINT32	lfo_pm_cnt;
  	UINT32	lfo_pm_inc;
  
  	UINT32	noise_rng;				/* 23 bit noise shift register	*/
  	UINT32	noise_p;				/* current noise 'phase'		*/
  	UINT32	noise_f;				/* current noise period			*/
  
  
  /* instrument settings */
  /*
  	0-user instrument
  	1-15 - fixed instruments
  	16 -bass drum settings
  	17,18 - other percussion instruments
  */
  	UINT8 inst_tab[19][8];
  
  	/* external event callback handlers */
  	OPLL_UPDATEHANDLER UpdateHandler; /* stream update handler		*/
  	int UpdateParam;				/* stream update parameter		*/
  
  	UINT32	fn_tab[1024];			/* fnumber->increment counter	*/
  
  	UINT8 address;					/* address register				*/
  	UINT8 status;					/* status flag					*/
  
  	int clock;						/* master clock  (Hz)			*/
  	int rate;						/* sampling rate (Hz)			*/
  	double freqbase;				/* frequency base				*/
  } YM2413;
  
  /* key scale level */
  /* table is 3dB/octave, DV converts this into 6dB/octave */
  /* 0.1875 is bit 0 weight of the envelope counter (volume) expressed in the 'decibel' scale */
  #define DV (0.1875/1.0)
  static const UINT32 ksl_tab[8*16]=
  {
  	/* OCT 0 */
  	 0.000/DV, 0.000/DV, 0.000/DV, 0.000/DV,
  	 0.000/DV, 0.000/DV, 0.000/DV, 0.000/DV,
  	 0.000/DV, 0.000/DV, 0.000/DV, 0.000/DV,
  	 0.000/DV, 0.000/DV, 0.000/DV, 0.000/DV,
  	/* OCT 1 */
  	 0.000/DV, 0.000/DV, 0.000/DV, 0.000/DV,
  	 0.000/DV, 0.000/DV, 0.000/DV, 0.000/DV,
  	 0.000/DV, 0.750/DV, 1.125/DV, 1.500/DV,
  	 1.875/DV, 2.250/DV, 2.625/DV, 3.000/DV,
  	/* OCT 2 */
  	 0.000/DV, 0.000/DV, 0.000/DV, 0.000/DV,
  	 0.000/DV, 1.125/DV, 1.875/DV, 2.625/DV,
  	 3.000/DV, 3.750/DV, 4.125/DV, 4.500/DV,
  	 4.875/DV, 5.250/DV, 5.625/DV, 6.000/DV,
  	/* OCT 3 */
  	 0.000/DV, 0.000/DV, 0.000/DV, 1.875/DV,
  	 3.000/DV, 4.125/DV, 4.875/DV, 5.625/DV,
  	 6.000/DV, 6.750/DV, 7.125/DV, 7.500/DV,
  	 7.875/DV, 8.250/DV, 8.625/DV, 9.000/DV,
  	/* OCT 4 */
  	 0.000/DV, 0.000/DV, 3.000/DV, 4.875/DV,
  	 6.000/DV, 7.125/DV, 7.875/DV, 8.625/DV,
  	 9.000/DV, 9.750/DV,10.125/DV,10.500/DV,
  	10.875/DV,11.250/DV,11.625/DV,12.000/DV,
  	/* OCT 5 */
  	 0.000/DV, 3.000/DV, 6.000/DV, 7.875/DV,
  	 9.000/DV,10.125/DV,10.875/DV,11.625/DV,
  	12.000/DV,12.750/DV,13.125/DV,13.500/DV,
  	13.875/DV,14.250/DV,14.625/DV,15.000/DV,
  	/* OCT 6 */
  	 0.000/DV, 6.000/DV, 9.000/DV,10.875/DV,
  	12.000/DV,13.125/DV,13.875/DV,14.625/DV,
  	15.000/DV,15.750/DV,16.125/DV,16.500/DV,
  	16.875/DV,17.250/DV,17.625/DV,18.000/DV,
  	/* OCT 7 */
  	 0.000/DV, 9.000/DV,12.000/DV,13.875/DV,
  	15.000/DV,16.125/DV,16.875/DV,17.625/DV,
  	18.000/DV,18.750/DV,19.125/DV,19.500/DV,
  	19.875/DV,20.250/DV,20.625/DV,21.000/DV
  };
  #undef DV
  
  /* sustain level table (3dB per step) */
  /* 0 - 15: 0, 3, 6, 9,12,15,18,21,24,27,30,33,36,39,42,45 (dB)*/
  #define SC(db) (UINT32) ( db * (1.0/ENV_STEP) )
  static const UINT32 sl_tab[16]={
   SC( 0),SC( 1),SC( 2),SC(3 ),SC(4 ),SC(5 ),SC(6 ),SC( 7),
   SC( 8),SC( 9),SC(10),SC(11),SC(12),SC(13),SC(14),SC(15)
  };
  #undef SC
  
  
  #define RATE_STEPS (8)
  static const unsigned char eg_inc[15*RATE_STEPS]={
  
  /*cycle:0 1  2 3  4 5  6 7*/
  
  /* 0 */ 0,1, 0,1, 0,1, 0,1, /* rates 00..12 0 (increment by 0 or 1) */
  /* 1 */ 0,1, 0,1, 1,1, 0,1, /* rates 00..12 1 */
  /* 2 */ 0,1, 1,1, 0,1, 1,1, /* rates 00..12 2 */
  /* 3 */ 0,1, 1,1, 1,1, 1,1, /* rates 00..12 3 */
  
  /* 4 */ 1,1, 1,1, 1,1, 1,1, /* rate 13 0 (increment by 1) */
  /* 5 */ 1,1, 1,2, 1,1, 1,2, /* rate 13 1 */
  /* 6 */ 1,2, 1,2, 1,2, 1,2, /* rate 13 2 */
  /* 7 */ 1,2, 2,2, 1,2, 2,2, /* rate 13 3 */
  
  /* 8 */ 2,2, 2,2, 2,2, 2,2, /* rate 14 0 (increment by 2) */
  /* 9 */ 2,2, 2,4, 2,2, 2,4, /* rate 14 1 */
  /*10 */ 2,4, 2,4, 2,4, 2,4, /* rate 14 2 */
  /*11 */ 2,4, 4,4, 2,4, 4,4, /* rate 14 3 */
  
  /*12 */ 4,4, 4,4, 4,4, 4,4, /* rates 15 0, 15 1, 15 2, 15 3 (increment by 4) */
  /*13 */ 8,8, 8,8, 8,8, 8,8, /* rates 15 2, 15 3 for attack */
  /*14 */ 0,0, 0,0, 0,0, 0,0, /* infinity rates for attack and decay(s) */
  };
  
  
  #define O(a) (a*RATE_STEPS)
  
  /*note that there is no O(13) in this table - it's directly in the code */
  static const unsigned char eg_rate_select[16+64+16]={	/* Envelope Generator rates (16 + 64 rates + 16 RKS) */
  /* 16 infinite time rates */
  O(14),O(14),O(14),O(14),O(14),O(14),O(14),O(14),
  O(14),O(14),O(14),O(14),O(14),O(14),O(14),O(14),
  
  /* rates 00-12 */
  O( 0),O( 1),O( 2),O( 3),
  O( 0),O( 1),O( 2),O( 3),
  O( 0),O( 1),O( 2),O( 3),
  O( 0),O( 1),O( 2),O( 3),
  O( 0),O( 1),O( 2),O( 3),
  O( 0),O( 1),O( 2),O( 3),
  O( 0),O( 1),O( 2),O( 3),
  O( 0),O( 1),O( 2),O( 3),
  O( 0),O( 1),O( 2),O( 3),
  O( 0),O( 1),O( 2),O( 3),
  O( 0),O( 1),O( 2),O( 3),
  O( 0),O( 1),O( 2),O( 3),
  O( 0),O( 1),O( 2),O( 3),
  
  /* rate 13 */
  O( 4),O( 5),O( 6),O( 7),
  
  /* rate 14 */
  O( 8),O( 9),O(10),O(11),
  
  /* rate 15 */
  O(12),O(12),O(12),O(12),
  
  /* 16 dummy rates (same as 15 3) */
  O(12),O(12),O(12),O(12),O(12),O(12),O(12),O(12),
  O(12),O(12),O(12),O(12),O(12),O(12),O(12),O(12),
  
  };
  #undef O
  
  /*rate  0,    1,    2,    3,    4,   5,   6,   7,  8,  9, 10, 11, 12, 13, 14, 15 */
  /*shift 13,   12,   11,   10,   9,   8,   7,   6,  5,  4,  3,  2,  1,  0,  0,  0 */
  /*mask  8191, 4095, 2047, 1023, 511, 255, 127, 63, 31, 15, 7,  3,  1,  0,  0,  0 */
  
  #define O(a) (a*1)
  static const unsigned char eg_rate_shift[16+64+16]={	/* Envelope Generator counter shifts (16 + 64 rates + 16 RKS) */
  /* 16 infinite time rates */
  O(0),O(0),O(0),O(0),O(0),O(0),O(0),O(0),
  O(0),O(0),O(0),O(0),O(0),O(0),O(0),O(0),
  
  /* rates 00-12 */
  O(13),O(13),O(13),O(13),
  O(12),O(12),O(12),O(12),
  O(11),O(11),O(11),O(11),
  O(10),O(10),O(10),O(10),
  O( 9),O( 9),O( 9),O( 9),
  O( 8),O( 8),O( 8),O( 8),
  O( 7),O( 7),O( 7),O( 7),
  O( 6),O( 6),O( 6),O( 6),
  O( 5),O( 5),O( 5),O( 5),
  O( 4),O( 4),O( 4),O( 4),
  O( 3),O( 3),O( 3),O( 3),
  O( 2),O( 2),O( 2),O( 2),
  O( 1),O( 1),O( 1),O( 1),
  
  /* rate 13 */
  O( 0),O( 0),O( 0),O( 0),
  
  /* rate 14 */
  O( 0),O( 0),O( 0),O( 0),
  
  /* rate 15 */
  O( 0),O( 0),O( 0),O( 0),
  
  /* 16 dummy rates (same as 15 3) */
  O( 0),O( 0),O( 0),O( 0),O( 0),O( 0),O( 0),O( 0),
  O( 0),O( 0),O( 0),O( 0),O( 0),O( 0),O( 0),O( 0),
  
  };
  #undef O
  
  
  /* multiple table */
  #define ML 2
  static const UINT8 mul_tab[16]= {
  /* 1/2, 1, 2, 3, 4, 5, 6, 7, 8, 9,10,10,12,12,15,15 */
     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*ML
  };
  #undef ML
  
  /*	TL_TAB_LEN is calculated as:
  *	11 - sinus amplitude bits     (Y axis)
  *	2  - sinus sign bit           (Y axis)
  *	TL_RES_LEN - sinus resolution (X axis)
  */
  #define TL_TAB_LEN (11*2*TL_RES_LEN)
  static signed int tl_tab[TL_TAB_LEN];
  
  #define ENV_QUIET		(TL_TAB_LEN>>5)
  
  /* sin waveform table in 'decibel' scale */
  /* two waveforms on OPLL type chips */
  static unsigned int sin_tab[SIN_LEN * 2];
  
  
  /* LFO Amplitude Modulation table (verified on real YM3812)
     27 output levels (triangle waveform); 1 level takes one of: 192, 256 or 448 samples
  
     Length: 210 elements.
  
  	Each of the elements has to be repeated
  	exactly 64 times (on 64 consecutive samples).
  	The whole table takes: 64 * 210 = 13440 samples.
  
  We use data>>1, until we find what it really is on real chip...
  
  */
  
  #define LFO_AM_TAB_ELEMENTS 210
  
  static const UINT8 lfo_am_table[LFO_AM_TAB_ELEMENTS] = {
  0,0,0,0,0,0,0,
  1,1,1,1,
  2,2,2,2,
  3,3,3,3,
  4,4,4,4,
  5,5,5,5,
  6,6,6,6,
  7,7,7,7,
  8,8,8,8,
  9,9,9,9,
  10,10,10,10,
  11,11,11,11,
  12,12,12,12,
  13,13,13,13,
  14,14,14,14,
  15,15,15,15,
  16,16,16,16,
  17,17,17,17,
  18,18,18,18,
  19,19,19,19,
  20,20,20,20,
  21,21,21,21,
  22,22,22,22,
  23,23,23,23,
  24,24,24,24,
  25,25,25,25,
  26,26,26,
  25,25,25,25,
  24,24,24,24,
  23,23,23,23,
  22,22,22,22,
  21,21,21,21,
  20,20,20,20,
  19,19,19,19,
  18,18,18,18,
  17,17,17,17,
  16,16,16,16,
  15,15,15,15,
  14,14,14,14,
  13,13,13,13,
  12,12,12,12,
  11,11,11,11,
  10,10,10,10,
  9,9,9,9,
  8,8,8,8,
  7,7,7,7,
  6,6,6,6,
  5,5,5,5,
  4,4,4,4,
  3,3,3,3,
  2,2,2,2,
  1,1,1,1
  };
  
  /* LFO Phase Modulation table (verified on real YM2413) */
  static const INT8 lfo_pm_table[8*8] = {
  
  /* FNUM2/FNUM = 0 00xxxxxx (0x0000) */
  0, 0, 0, 0, 0, 0, 0, 0,
  
  /* FNUM2/FNUM = 0 01xxxxxx (0x0040) */
  1, 0, 0, 0,-1, 0, 0, 0,
  
  /* FNUM2/FNUM = 0 10xxxxxx (0x0080) */
  2, 1, 0,-1,-2,-1, 0, 1,
  
  /* FNUM2/FNUM = 0 11xxxxxx (0x00C0) */
  3, 1, 0,-1,-3,-1, 0, 1,
  
  /* FNUM2/FNUM = 1 00xxxxxx (0x0100) */
  4, 2, 0,-2,-4,-2, 0, 2,
  
  /* FNUM2/FNUM = 1 01xxxxxx (0x0140) */
  5, 2, 0,-2,-5,-2, 0, 2,
  
  /* FNUM2/FNUM = 1 10xxxxxx (0x0180) */
  6, 3, 0,-3,-6,-3, 0, 3,
  
  /* FNUM2/FNUM = 1 11xxxxxx (0x01C0) */
  7, 3, 0,-3,-7,-3, 0, 3,
  };
  
  
  
  
  
  
  /* This is not 100% perfect yet but very close */
  /*
   - multi parameters are 100% correct (instruments and drums)
   - LFO PM and AM enable are 100% correct
   - waveform DC and DM select are 100% correct
  */
  
  static unsigned char table[19][8] = {
  /* MULT  MULT modTL DcDmFb AR/DR AR/DR SL/RR SL/RR */
  /*   0     1     2     3     4     5     6    7    */
    {0x49, 0x4c, 0x4c, 0x12, 0x00, 0x00, 0x00, 0x00 },	/*0*/
  
    {0x61, 0x61, 0x1e, 0x17, 0xf0, 0x78, 0x00, 0x17 },	/*1*/
    {0x13, 0x41, 0x1e, 0x0d, 0xd7, 0xf7, 0x13, 0x13 },	/*2*/
    {0x13, 0x01, 0x99, 0x04, 0xf2, 0xf4, 0x11, 0x23 },	/*3*/
    {0x21, 0x61, 0x1b, 0x07, 0xaf, 0x64, 0x40, 0x27 },	/*4*/
  
  /*{0x22, 0x21, 0x1e, 0x09, 0xf0, 0x76, 0x08, 0x28 },	*/ /*5*/
    {0x22, 0x21, 0x1e, 0x06, 0xf0, 0x75, 0x08, 0x18 },	/*5*/
  
  /*{0x31, 0x22, 0x16, 0x09, 0x90, 0x7f, 0x00, 0x08 },	*/ /*6*/
    {0x31, 0x22, 0x16, 0x05, 0x90, 0x71, 0x00, 0x13 },	/*6*/
  
    {0x21, 0x61, 0x1d, 0x07, 0x82, 0x80, 0x10, 0x17 },	/*7*/
    {0x23, 0x21, 0x2d, 0x16, 0xc0, 0x70, 0x07, 0x07 },	/*8*/
    {0x61, 0x61, 0x1b, 0x06, 0x64, 0x65, 0x10, 0x17 },	/*9*/
  
  /*{0x61, 0x61, 0x0c, 0x08, 0x85, 0xa0, 0x79, 0x07 },	*/ /*A*/
    {0x61, 0x61, 0x0c, 0x18, 0x85, 0xf0, 0x70, 0x07 },	/*A*/
  
    {0x23, 0x01, 0x07, 0x11, 0xf0, 0xa4, 0x00, 0x22 },	/*B*/
    {0x97, 0xc1, 0x24, 0x07, 0xff, 0xf8, 0x22, 0x12 },	/*C*/
  
  /*{0x61, 0x10, 0x0c, 0x08, 0xf2, 0xc4, 0x40, 0xc8 },	*/ /*D*/
    {0x61, 0x10, 0x0c, 0x05, 0xf2, 0xf4, 0x40, 0x44 },	/*D*/
  
    {0x01, 0x01, 0x55, 0x03, 0xf3, 0x92, 0xf3, 0xf3 },	/*E*/
    {0x61, 0x41, 0x89, 0x03, 0xf1, 0xf4, 0xf0, 0x13 },	/*F*/
  
  /* drum instruments definitions */
  /* MULTI MULTI modTL  xxx  AR/DR AR/DR SL/RR SL/RR */
  /*   0     1     2     3     4     5     6    7    */
    {0x01, 0x01, 0x16, 0x00, 0xfd, 0xf8, 0x2f, 0x6d },/* BD(multi verified, modTL verified, mod env - verified(close), carr. env verifed) */
    {0x01, 0x01, 0x00, 0x00, 0xd8, 0xd8, 0xf9, 0xf8 },/* HH(multi verified), SD(multi not used) */
    {0x05, 0x01, 0x00, 0x00, 0xf8, 0xba, 0x49, 0x55 },/* TOM(multi,env verified), TOP CYM(multi verified, env verified) */
  };
  
  /* lock level of common table */
  static int num_lock = 0;
  
  /* work table */
  static void *cur_chip = NULL;	/* current chip pointer */
  static OPLL_SLOT *SLOT7_1,*SLOT7_2,*SLOT8_1,*SLOT8_2;
  
  static signed int output[2];
  static signed int outchan;
  
  static UINT32	LFO_AM;
  static INT32	LFO_PM;
  
  /* advance LFO to next sample */
  static INLINE void advance_lfo(YM2413 *chip)
  {
  	/* LFO */
  	chip->lfo_am_cnt += chip->lfo_am_inc;
  	if (chip->lfo_am_cnt >= (LFO_AM_TAB_ELEMENTS<<LFO_SH) )	/* lfo_am_table is 210 elements long */
  		chip->lfo_am_cnt -= (LFO_AM_TAB_ELEMENTS<<LFO_SH);
  
  	LFO_AM = lfo_am_table[ chip->lfo_am_cnt >> LFO_SH ] >> 1;
  
  	chip->lfo_pm_cnt += chip->lfo_pm_inc;
  	LFO_PM = (chip->lfo_pm_cnt>>LFO_SH) & 7;
  }
  
  /* advance to next sample */
  static INLINE void advance(YM2413 *chip)
  {
  	OPLL_CH *CH;
  	OPLL_SLOT *op;
  	unsigned int i;
  
  /*profiler_mark(PROFILER_USER3);*/
  
  	/* Envelope Generator */
  	chip->eg_timer += chip->eg_timer_add;
  
  	while (chip->eg_timer >= chip->eg_timer_overflow)
  	{
  		chip->eg_timer -= chip->eg_timer_overflow;
  
  		chip->eg_cnt++;
  
  		for (i=0; i<9*2; i++)
  		{
  			CH  = &chip->P_CH[i/2];
  
  			op  = &CH->SLOT[i&1];
  
  			switch(op->state)
  			{
  
  			case EG_DMP:		/* dump phase */
  			/*dump phase is performed by both operators in each channel*/
  			/*when CARRIER envelope gets down to zero level,
  			**  phases in BOTH opearators are reset (at the same time ?)
  			*/
  				if ( !(chip->eg_cnt & ((1<<op->eg_sh_dp)-1) ) )
  				{
  					op->volume += eg_inc[op->eg_sel_dp + ((chip->eg_cnt>>op->eg_sh_dp)&7)];
  
  					if ( op->volume >= MAX_ATT_INDEX )
  					{
  						op->volume = MAX_ATT_INDEX;
  						op->state = EG_ATT;
  						/* restart Phase Generator  */
  						op->phase = 0;
  					}
  				}
  			break;
  
  			case EG_ATT:		/* attack phase */
  				if ( !(chip->eg_cnt & ((1<<op->eg_sh_ar)-1) ) )
  				{
  					op->volume += (~op->volume *
  	                        		           (eg_inc[op->eg_sel_ar + ((chip->eg_cnt>>op->eg_sh_ar)&7)])
          			                          ) >>2;
  
  					if (op->volume <= MIN_ATT_INDEX)
  					{
  						op->volume = MIN_ATT_INDEX;
  						op->state = EG_DEC;
  					}
  				}
  			break;
  
  			case EG_DEC:	/* decay phase */
  				if ( !(chip->eg_cnt & ((1<<op->eg_sh_dr)-1) ) )
  				{
  					op->volume += eg_inc[op->eg_sel_dr + ((chip->eg_cnt>>op->eg_sh_dr)&7)];
  
  					if ( op->volume >= op->sl )
  						op->state = EG_SUS;
  				}
  			break;
  
  			case EG_SUS:	/* sustain phase */
  				/* this is important behaviour:
  				one can change percusive/non-percussive modes on the fly and
  				the chip will remain in sustain phase - verified on real YM3812 */
  
  				if(op->eg_type)		/* non-percussive mode (sustained tone) */
  				{
  									/* do nothing */
  				}
  				else				/* percussive mode */
  				{
  					/* during sustain phase chip adds Release Rate (in percussive mode) */
  					if ( !(chip->eg_cnt & ((1<<op->eg_sh_rr)-1) ) )
  					{
  						op->volume += eg_inc[op->eg_sel_rr + ((chip->eg_cnt>>op->eg_sh_rr)&7)];
  
  						if ( op->volume >= MAX_ATT_INDEX )
  							op->volume = MAX_ATT_INDEX;
  					}
  					/* else do nothing in sustain phase */
  				}
  			break;
  
  			case EG_REL:	/* release phase */
  			/* exclude modulators in melody channels from performing anything in this mode*/
  			/* allowed are only carriers in melody mode and rhythm slots in rhythm mode */
  
  			/*This table shows which operators and on what conditions are allowed to perform EG_REL:
  			(a) - always perform EG_REL
  			(n) - never perform EG_REL
  			(r) - perform EG_REL in Rhythm mode ONLY
  				0: 0 (n),  1 (a)
  				1: 2 (n),  3 (a)
  				2: 4 (n),  5 (a)
  				3: 6 (n),  7 (a)
  				4: 8 (n),  9 (a)
  				5: 10(n),  11(a)
  				6: 12(r),  13(a)
  				7: 14(r),  15(a)
  				8: 16(r),  17(a)
  			*/
  				if ( (i&1) || ((chip->rhythm&0x20) && (i>=12)) )/* exclude modulators */
  				{
  					if(op->eg_type)		/* non-percussive mode (sustained tone) */
  					/*this is correct: use RR when SUS = OFF*/
  					/*and use RS when SUS = ON*/
  					{
  						if (CH->sus)
  						{
  							if ( !(chip->eg_cnt & ((1<<op->eg_sh_rs)-1) ) )
  							{
  								op->volume += eg_inc[op->eg_sel_rs + ((chip->eg_cnt>>op->eg_sh_rs)&7)];
  								if ( op->volume >= MAX_ATT_INDEX )
  								{
  									op->volume = MAX_ATT_INDEX;
  									op->state = EG_OFF;
  								}
  							}
  						}
  						else
  						{
  							if ( !(chip->eg_cnt & ((1<<op->eg_sh_rr)-1) ) )
  							{
  								op->volume += eg_inc[op->eg_sel_rr + ((chip->eg_cnt>>op->eg_sh_rr)&7)];
  								if ( op->volume >= MAX_ATT_INDEX )
  								{
  									op->volume = MAX_ATT_INDEX;
  									op->state = EG_OFF;
  								}
  							}
  						}
  					}
  					else				/* percussive mode */
  					{
  						if ( !(chip->eg_cnt & ((1<<op->eg_sh_rs)-1) ) )
  						{
  							op->volume += eg_inc[op->eg_sel_rs + ((chip->eg_cnt>>op->eg_sh_rs)&7)];
  							if ( op->volume >= MAX_ATT_INDEX )
  							{
  								op->volume = MAX_ATT_INDEX;
  								op->state = EG_OFF;
  							}
  						}
  					}
  				}
  			break;
  
  			default:
  			break;
  			}
  		}
  	}
  
  /*profiler_mark(PROFILER_END);*/
  
  /*profiler_mark(PROFILER_USER4);*/
  
  	for (i=0; i<9*2; i++)
  	{
  		CH  = &chip->P_CH[i/2];
  		op  = &CH->SLOT[i&1];
  
  		/* Phase Generator */
  		if(op->vib)
  		{
  			UINT8 block;
  
  			unsigned int fnum_lfo   = 8*((CH->block_fnum&0x01c0) >> 6);
  			unsigned int block_fnum = CH->block_fnum * 2;
  			signed int lfo_fn_table_index_offset = lfo_pm_table[LFO_PM + fnum_lfo ];
  
  			if (lfo_fn_table_index_offset)	/* LFO phase modulation active */
  			{
  				block_fnum += lfo_fn_table_index_offset;
  				block = (block_fnum&0x1c00) >> 10;
  				op->phase += (chip->fn_tab[block_fnum&0x03ff] >> (7-block)) * op->mul;
  			}
  			else	/* LFO phase modulation  = zero */
  			{
  				op->phase += op->freq;
  			}
  		}
  		else	/* LFO phase modulation disabled for this operator */
  		{
  			op->phase += op->freq;
  		}
  	}
  
  	/*	The Noise Generator of the YM3812 is 23-bit shift register.
  	*	Period is equal to 2^23-2 samples.
  	*	Register works at sampling frequency of the chip, so output
  	*	can change on every sample.
  	*
  	*	Output of the register and input to the bit 22 is:
  	*	bit0 XOR bit14 XOR bit15 XOR bit22
  	*
  	*	Simply use bit 22 as the noise output.
  	*/
  
  	chip->noise_p += chip->noise_f;
  	i = chip->noise_p >> FREQ_SH;		/* number of events (shifts of the shift register) */
  	chip->noise_p &= FREQ_MASK;
  	while (i)
  	{
  		/*
  		UINT32 j;
  		j = ( (chip->noise_rng) ^ (chip->noise_rng>>14) ^ (chip->noise_rng>>15) ^ (chip->noise_rng>>22) ) & 1;
  		chip->noise_rng = (j<<22) | (chip->noise_rng>>1);
  		*/
  
  		/*
  			Instead of doing all the logic operations above, we
  			use a trick here (and use bit 0 as the noise output).
  			The difference is only that the noise bit changes one
  			step ahead. This doesn't matter since we don't know
  			what is real state of the noise_rng after the reset.
  		*/
  
  		if (chip->noise_rng & 1) chip->noise_rng ^= 0x800302;
  		chip->noise_rng >>= 1;
  
  		i--;
  	}
  /*profiler_mark(PROFILER_END);*/
  }
  
  
  static INLINE signed int op_calc(UINT32 phase, unsigned int env, signed int pm, unsigned int wave_tab)
  {
  	UINT32 p;
  
  	p = (env<<5) + sin_tab[wave_tab + ((((signed int)((phase & ~FREQ_MASK) + (pm<<17))) >> FREQ_SH ) & SIN_MASK) ];
  
  	if (p >= TL_TAB_LEN)
  		return 0;
  	return tl_tab[p];
  }
  
  static INLINE signed int op_calc1(UINT32 phase, unsigned int env, signed int pm, unsigned int wave_tab)
  {
  	UINT32 p;
  	INT32  i;
  
  	i = (phase & ~FREQ_MASK) + pm;
  
  /*logerror("i=%08x (i>>16)&511=%8i phase=%i [pm=%08x] ",i, (i>>16)&511, phase>>FREQ_SH, pm);*/
  
  	p = (env<<5) + sin_tab[ wave_tab + ((i>>FREQ_SH) & SIN_MASK)];
  
  /*logerror("(p&255=%i p>>8=%i) out= %i\n", p&255,p>>8, tl_tab[p&255]>>(p>>8) );*/
  
  	if (p >= TL_TAB_LEN)
  		return 0;
  	return tl_tab[p];
  }
  
  
  #define volume_calc(OP) ((OP)->TLL + ((UINT32)(OP)->volume) + (LFO_AM & (OP)->AMmask))
  
  /* calculate output */
  static INLINE void chan_calc( OPLL_CH *CH )
  {
  	OPLL_SLOT *SLOT;
  	unsigned int env;
  	signed int out;
  	signed int phase_modulation;	/* phase modulation input (SLOT 2) */
  
  
  	/* SLOT 1 */
  	SLOT = &CH->SLOT[SLOT1];
  	env  = volume_calc(SLOT);
  	out  = SLOT->op1_out[0] + SLOT->op1_out[1];
  
  	SLOT->op1_out[0] = SLOT->op1_out[1];
  	phase_modulation = SLOT->op1_out[0];
  
  	SLOT->op1_out[1] = 0;
  
  	if( env < ENV_QUIET )
  	{
  		if (!SLOT->fb_shift)
  			out = 0;
  		SLOT->op1_out[1] = op_calc1(SLOT->phase, env, (out<<SLOT->fb_shift), SLOT->wavetable );
  	}
  
  	/* SLOT 2 */
  
  outchan=0;
  
  	SLOT++;
  	env = volume_calc(SLOT);
  	if( env < ENV_QUIET )
  	{
  		signed int outp = op_calc(SLOT->phase, env, phase_modulation, SLOT->wavetable);
  		output[0] += outp;
  		outchan = outp;
  		/*output[0] += op_calc(SLOT->phase, env, phase_modulation, SLOT->wavetable);*/
  	}
  }
  
  /*
  	operators used in the rhythm sounds generation process:
  
  	Envelope Generator:
  
  channel  operator  register number   Bass  High  Snare Tom  Top
  / slot   number    TL ARDR SLRR Wave Drum  Hat   Drum  Tom  Cymbal
   6 / 0   12        50  70   90   f0  +
   6 / 1   15        53  73   93   f3  +
   7 / 0   13        51  71   91   f1        +
   7 / 1   16        54  74   94   f4              +
   8 / 0   14        52  72   92   f2                    +
   8 / 1   17        55  75   95   f5                          +
  
  	Phase Generator:
  
  channel  operator  register number   Bass  High  Snare Tom  Top
  / slot   number    MULTIPLE          Drum  Hat   Drum  Tom  Cymbal
   6 / 0   12        30                +
   6 / 1   15        33                +
   7 / 0   13        31                      +     +           +
   7 / 1   16        34                -----  n o t  u s e d -----
   8 / 0   14        32                                  +
   8 / 1   17        35                      +                 +
  
  channel  operator  register number   Bass  High  Snare Tom  Top
  number   number    BLK/FNUM2 FNUM    Drum  Hat   Drum  Tom  Cymbal
     6     12,15     B6        A6      +
  
     7     13,16     B7        A7            +     +           +
  
     8     14,17     B8        A8            +           +     +
  
  */
  
  /* calculate rhythm */
  
  static INLINE void rhythm_calc( OPLL_CH *CH, unsigned int noise )
  {
  	OPLL_SLOT *SLOT;
  	signed int out;
  	unsigned int env;
  	signed int phase_modulation;	/* phase modulation input (SLOT 2) */
  
  
  	/* Bass Drum (verified on real YM3812):
  	  - depends on the channel 6 'connect' register:
  	      when connect = 0 it works the same as in normal (non-rhythm) mode (op1->op2->out)
  	      when connect = 1 _only_ operator 2 is present on output (op2->out), operator 1 is ignored
  	  - output sample always is multiplied by 2
  	*/
  
  
  	/* SLOT 1 */
  	SLOT = &CH[6].SLOT[SLOT1];
  	env = volume_calc(SLOT);
  
  	out = SLOT->op1_out[0] + SLOT->op1_out[1];
  	SLOT->op1_out[0] = SLOT->op1_out[1];
  
  	phase_modulation = SLOT->op1_out[0];
  
  	SLOT->op1_out[1] = 0;
  	if( env < ENV_QUIET )
  	{
  		if (!SLOT->fb_shift)
  			out = 0;
  		SLOT->op1_out[1] = op_calc1(SLOT->phase, env, (out<<SLOT->fb_shift), SLOT->wavetable );
  	}
  
  	/* SLOT 2 */
  	SLOT++;
  	env = volume_calc(SLOT);
  	if( env < ENV_QUIET )
  		output[1] += op_calc(SLOT->phase, env, phase_modulation, SLOT->wavetable) * 2;
  
  
  	/* Phase generation is based on: */
  	/* HH  (13) channel 7->slot 1 combined with channel 8->slot 2 (same combination as TOP CYMBAL but different output phases)*/
  	/* SD  (16) channel 7->slot 1*/
  	/* TOM (14) channel 8->slot 1*/
  	/* TOP (17) channel 7->slot 1 combined with channel 8->slot 2 (same combination as HIGH HAT but different output phases)*/
  
  	/* Envelope generation based on: */
  	/* HH  channel 7->slot1*/
  	/* SD  channel 7->slot2*/
  	/* TOM channel 8->slot1*/
  	/* TOP channel 8->slot2*/
  
  
  	/* The following formulas can be well optimized.
  	   I leave them in direct form for now (in case I've missed something).
  	*/
  
  	/* High Hat (verified on real YM3812) */
  	env = volume_calc(SLOT7_1);
  	if( env < ENV_QUIET )
  	{
  
  		/* high hat phase generation:
  			phase = d0 or 234 (based on frequency only)
  			phase = 34 or 2d0 (based on noise)
  		*/
  
  		/* base frequency derived from operator 1 in channel 7 */
  		unsigned char bit7 = ((SLOT7_1->phase>>FREQ_SH)>>7)&1;
  		unsigned char bit3 = ((SLOT7_1->phase>>FREQ_SH)>>3)&1;
  		unsigned char bit2 = ((SLOT7_1->phase>>FREQ_SH)>>2)&1;
  
  		unsigned char res1 = (bit2 ^ bit7) | bit3;
  
  		/* when res1 = 0 phase = 0x000 | 0xd0; */
  		/* when res1 = 1 phase = 0x200 | (0xd0>>2); */
  		UINT32 phase = res1 ? (0x200|(0xd0>>2)) : 0xd0;
  
  		/* enable gate based on frequency of operator 2 in channel 8 */
  		unsigned char bit5e= ((SLOT8_2->phase>>FREQ_SH)>>5)&1;
  		unsigned char bit3e= ((SLOT8_2->phase>>FREQ_SH)>>3)&1;
  
  		unsigned char res2 = (bit3e | bit5e);
  
  		/* when res2 = 0 pass the phase from calculation above (res1); */
  		/* when res2 = 1 phase = 0x200 | (0xd0>>2); */
  		if (res2)
  			phase = (0x200|(0xd0>>2));
  
  
  		/* when phase & 0x200 is set and noise=1 then phase = 0x200|0xd0 */
  		/* when phase & 0x200 is set and noise=0 then phase = 0x200|(0xd0>>2), ie no change */
  		if (phase&0x200)
  		{
  			if (noise)
  				phase = 0x200|0xd0;
  		}
  		else
  		/* when phase & 0x200 is clear and noise=1 then phase = 0xd0>>2 */
  		/* when phase & 0x200 is clear and noise=0 then phase = 0xd0, ie no change */
  		{
  			if (noise)
  				phase = 0xd0>>2;
  		}
  
  		output[1] += op_calc(phase<<FREQ_SH, env, 0, SLOT7_1->wavetable) * 2;
  	}
  
  	/* Snare Drum (verified on real YM3812) */
  	env = volume_calc(SLOT7_2);
  	if( env < ENV_QUIET )
  	{
  		/* base frequency derived from operator 1 in channel 7 */
  		unsigned char bit8 = ((SLOT7_1->phase>>FREQ_SH)>>8)&1;
  
  		/* when bit8 = 0 phase = 0x100; */
  		/* when bit8 = 1 phase = 0x200; */
  		UINT32 phase = bit8 ? 0x200 : 0x100;
  
  		/* Noise bit XOR'es phase by 0x100 */
  		/* when noisebit = 0 pass the phase from calculation above */
  		/* when noisebit = 1 phase ^= 0x100; */
  		/* in other words: phase ^= (noisebit<<8); */
  		if (noise)
  			phase ^= 0x100;
  
  		output[1] += op_calc(phase<<FREQ_SH, env, 0, SLOT7_2->wavetable) * 2;
  	}
  
  	/* Tom Tom (verified on real YM3812) */
  	env = volume_calc(SLOT8_1);
  	if( env < ENV_QUIET )
  		output[1] += op_calc(SLOT8_1->phase, env, 0, SLOT8_1->wavetable) * 2;
  
  	/* Top Cymbal (verified on real YM2413) */
  	env = volume_calc(SLOT8_2);
  	if( env < ENV_QUIET )
  	{
  		/* base frequency derived from operator 1 in channel 7 */
  		unsigned char bit7 = ((SLOT7_1->phase>>FREQ_SH)>>7)&1;
  		unsigned char bit3 = ((SLOT7_1->phase>>FREQ_SH)>>3)&1;
  		unsigned char bit2 = ((SLOT7_1->phase>>FREQ_SH)>>2)&1;
  
  		unsigned char res1 = (bit2 ^ bit7) | bit3;
  
  		/* when res1 = 0 phase = 0x000 | 0x100; */
  		/* when res1 = 1 phase = 0x200 | 0x100; */
  		UINT32 phase = res1 ? 0x300 : 0x100;
  
  		/* enable gate based on frequency of operator 2 in channel 8 */
  		unsigned char bit5e= ((SLOT8_2->phase>>FREQ_SH)>>5)&1;
  		unsigned char bit3e= ((SLOT8_2->phase>>FREQ_SH)>>3)&1;
  
  		unsigned char res2 = (bit3e | bit5e);
  		/* when res2 = 0 pass the phase from calculation above (res1); */
  		/* when res2 = 1 phase = 0x200 | 0x100; */
  		if (res2)
  			phase = 0x300;
  
  		output[1] += op_calc(phase<<FREQ_SH, env, 0, SLOT8_2->wavetable) * 2;
  	}
  
  }
  
  
  /* generic table initialize */
  static int init_tables(void)
  {
  	signed int i,x;
  	signed int n;
  	double o,m;
  
  
  	for (x=0; x<TL_RES_LEN; x++)
  	{
  		m = (1<<16) / pow(2, (x+1) * (ENV_STEP/4.0) / 8.0);
  		m = floor(m);
  
  		/* we never reach (1<<16) here due to the (x+1) */
  		/* result fits within 16 bits at maximum */
  
  		n = (int)m;		/* 16 bits here */
  		n >>= 4;		/* 12 bits here */
  		if (n&1)		/* round to nearest */
  			n = (n>>1)+1;
  		else
  			n = n>>1;
  						/* 11 bits here (rounded) */
  		tl_tab[ x*2 + 0 ] = n;
  		tl_tab[ x*2 + 1 ] = -tl_tab[ x*2 + 0 ];
  
  		for (i=1; i<11; i++)
  		{
  			tl_tab[ x*2+0 + i*2*TL_RES_LEN ] =  tl_tab[ x*2+0 ]>>i;
  			tl_tab[ x*2+1 + i*2*TL_RES_LEN ] = -tl_tab[ x*2+0 + i*2*TL_RES_LEN ];
  		}
  
      log_cb(RETRO_LOG_DEBUG, LOGPRE "tl %04i", x*2);
      for (i=0; i<11; i++)
        log_cb(RETRO_LOG_DEBUG, LOGPRE ", [%02i] %5i", i*2, tl_tab[ x*2 /*+1*/ + i*2*TL_RES_LEN ] );
      log_cb(RETRO_LOG_DEBUG, LOGPRE "\n");
  	}
  	/*logerror("ym2413.c: TL_TAB_LEN = %i elements (%i bytes)\n",TL_TAB_LEN, (int)sizeof(tl_tab));*/
  
  
  	for (i=0; i<SIN_LEN; i++)
  	{
  		/* non-standard sinus */
  		m = sin( ((i*2)+1) * PI / SIN_LEN ); /* checked against the real chip */
  
  		/* we never reach zero here due to ((i*2)+1) */
  
  		if (m>0.0)
  			o = 8*log(1.0/m)/log(2);	/* convert to 'decibels' */
  		else
  			o = 8*log(-1.0/m)/log(2);	/* convert to 'decibels' */
  
  		o = o / (ENV_STEP/4);
  
  		n = (int)(2.0*o);
  		if (n&1)						/* round to nearest */
  			n = (n>>1)+1;
  		else
  			n = n>>1;
  
  		/* waveform 0: standard sinus  */
  		sin_tab[ i ] = n*2 + (m>=0.0? 0: 1 );
  
  		/*logerror("ym2413.c: sin [%4i (hex=%03x)]= %4i (tl_tab value=%5i)\n", i, i, sin_tab[i], tl_tab[sin_tab[i]] );*/
  
  
  		/* waveform 1:  __      __     */
  		/*             /  \____/  \____*/
  		/* output only first half of the sinus waveform (positive one) */
  		if (i & (1<<(SIN_BITS-1)) )
  			sin_tab[1*SIN_LEN+i] = TL_TAB_LEN;
  		else
  			sin_tab[1*SIN_LEN+i] = sin_tab[i];
  
  		/*logerror("ym2413.c: sin1[%4i]= %4i (tl_tab value=%5i)\n", i, sin_tab[1*SIN_LEN+i], tl_tab[sin_tab[1*SIN_LEN+i]] );*/
  	}
  
    log_cb(RETRO_LOG_DEBUG, LOGPRE "YM2413.C: ENV_QUIET= %08x (*32=%08x)\n", ENV_QUIET, ENV_QUIET*32 );
  	for (i=0; i<ENV_QUIET; i++)
  	{
  		log_cb(RETRO_LOG_DEBUG, LOGPRE "tl_tb[%4x(%4i)]=%8x\n", i<<5, i, tl_tab[i<<5] );
  	}
  #ifdef SAVE_SAMPLE
  	sample[0]=fopen("sampsum.pcm","wb");
  #endif
  
  	return 1;
  }
  
  static void OPLCloseTable( void )
  {
  #ifdef SAVE_SAMPLE
  	fclose(sample[0]);
  #endif
  }
  
  
  
  static void OPLL_initalize(YM2413 *chip)
  {
  	int i;
  
  	/* frequency base */
  	chip->freqbase  = (chip->rate) ? ((double)chip->clock / 72.0) / chip->rate  : 0;
  #if 0
  	chip->rate = (double)chip->clock / 72.0;
  	chip->freqbase  = 1.0;
  	log_cb(RETRO_LOG_DEBUG, LOGPRE "freqbase=%f\n", chip->freqbase);
  #endif
  
  
  
  	/* make fnumber -> increment counter table */
  	for( i = 0 ; i < 1024; i++ )
  	{
  		/* OPLL (YM2413) phase increment counter = 18bit */
  
  		chip->fn_tab[i] = (UINT32)( (double)i * 64 * chip->freqbase * (1<<(FREQ_SH-10)) ); /* -10 because chip works with 10.10 fixed point, while we use 16.16 */
  #if 0
  		logerror("ym2413.c: fn_tab[%4i] = %08x (dec=%8i)\n",
  				 i, chip->fn_tab[i]>>6, chip->fn_tab[i]>>6 );
  #endif
  	}
  
  #if 0
  	for( i=0 ; i < 16 ; i++ )
  	{
  		log_cb(RETRO_LOG_DEBUG, LOGPRE "ym2413.c: sl_tab[%i] = %08x\n", i, sl_tab[i] );
  	}
  	for( i=0 ; i < 8 ; i++ )
  	{
  		int j;
  		log_cb(RETRO_LOG_DEBUG, LOGPRE "ym2413.c: ksl_tab[oct=%2i] =",i);
  		for (j=0; j<16; j++)
  		{
  			log_cb(RETRO_LOG_DEBUG, LOGPRE "%08x ", ksl_tab[i*16+j] );
  		}
  		log_cb(RETRO_LOG_DEBUG, LOGPRE "\n");
  	}
  #endif
  
  
  	/* Amplitude modulation: 27 output levels (triangle waveform); 1 level takes one of: 192, 256 or 448 samples */
  	/* One entry from LFO_AM_TABLE lasts for 64 samples */
  	chip->lfo_am_inc = (1.0 / 64.0 ) * (1<<LFO_SH) * chip->freqbase;
  
  	/* Vibrato: 8 output levels (triangle waveform); 1 level takes 1024 samples */
  	chip->lfo_pm_inc = (1.0 / 1024.0) * (1<<LFO_SH) * chip->freqbase;
  
  	/*logerror ("chip->lfo_am_inc = %8x ; chip->lfo_pm_inc = %8x\n", chip->lfo_am_inc, chip->lfo_pm_inc);*/
  
  	/* Noise generator: a step takes 1 sample */
  	chip->noise_f = (1.0 / 1.0) * (1<<FREQ_SH) * chip->freqbase;
  	/*logerror("YM2413init noise_f=%8x\n", chip->noise_f);*/
  
  	chip->eg_timer_add  = (1<<EG_SH)  * chip->freqbase;
  	chip->eg_timer_overflow = ( 1 ) * (1<<EG_SH);
  	/*logerror("YM2413init eg_timer_add=%8x eg_timer_overflow=%8x\n", chip->eg_timer_add, chip->eg_timer_overflow);*/
  
  }
  
  static INLINE void KEY_ON(OPLL_SLOT *SLOT, UINT32 key_set)
  {
  	if( !SLOT->key )
  	{
  		/* do NOT restart Phase Generator (verified on real YM2413)*/
  		/* phase -> Dump */
  		SLOT->state = EG_DMP;
  	}
  	SLOT->key |= key_set;
  }
  
  static INLINE void KEY_OFF(OPLL_SLOT *SLOT, UINT32 key_clr)
  {
  	if( SLOT->key )
  	{
  		SLOT->key &= key_clr;
  
  		if( !SLOT->key )
  		{
  			/* phase -> Release */
  			if (SLOT->state>EG_REL)
  				SLOT->state = EG_REL;
  		}
  	}
  }
  
  /* update phase increment counter of operator (also update the EG rates if necessary) */
  static INLINE void CALC_FCSLOT(OPLL_CH *CH,OPLL_SLOT *SLOT)
  {
  	int ksr;
  	UINT32 SLOT_rs;
  	UINT32 SLOT_dp;
  
  	/* (frequency) phase increment counter */
  	SLOT->freq = CH->fc * SLOT->mul;
  	ksr = CH->kcode >> SLOT->KSR;
  
  	if( SLOT->ksr != ksr )
  	{
  		SLOT->ksr = ksr;
  
  		/* calculate envelope generator rates */
  		if ((SLOT->ar + SLOT->ksr) < 16+62)
  		{
  			SLOT->eg_sh_ar  = eg_rate_shift [SLOT->ar + SLOT->ksr ];
  			SLOT->eg_sel_ar = eg_rate_select[SLOT->ar + SLOT->ksr ];
  		}
  		else
  		{
  			SLOT->eg_sh_ar  = 0;
  			SLOT->eg_sel_ar = 13*RATE_STEPS;
  		}
  		SLOT->eg_sh_dr  = eg_rate_shift [SLOT->dr + SLOT->ksr ];
  		SLOT->eg_sel_dr = eg_rate_select[SLOT->dr + SLOT->ksr ];
  		SLOT->eg_sh_rr  = eg_rate_shift [SLOT->rr + SLOT->ksr ];
  		SLOT->eg_sel_rr = eg_rate_select[SLOT->rr + SLOT->ksr ];
  
  	}
  
  	if (CH->sus)
  		SLOT_rs  = 16 + (5<<2);
  	else
  		SLOT_rs  = 16 + (7<<2);
  
  	SLOT->eg_sh_rs  = eg_rate_shift [SLOT_rs + SLOT->ksr ];
  	SLOT->eg_sel_rs = eg_rate_select[SLOT_rs + SLOT->ksr ];
  
  	SLOT_dp  = 16 + (13<<2);
  	SLOT->eg_sh_dp  = eg_rate_shift [SLOT_dp + SLOT->ksr ];
  	SLOT->eg_sel_dp = eg_rate_select[SLOT_dp + SLOT->ksr ];
  }
  
  /* set multi,am,vib,EG-TYP,KSR,mul */
  static INLINE void set_mul(YM2413 *chip,int slot,int v)
  {
  	OPLL_CH   *CH   = &chip->P_CH[slot/2];
  	OPLL_SLOT *SLOT = &CH->SLOT[slot&1];
  
  	SLOT->mul     = mul_tab[v&0x0f];
  	SLOT->KSR     = (v&0x10) ? 0 : 2;
  	SLOT->eg_type = (v&0x20);
  	SLOT->vib     = (v&0x40);
  	SLOT->AMmask  = (v&0x80) ? ~0 : 0;
  	CALC_FCSLOT(CH,SLOT);
  }
  
  /* set ksl, tl */
  static INLINE void set_ksl_tl(YM2413 *chip,int chan,int v)
  {
  	int ksl;
  	OPLL_CH   *CH   = &chip->P_CH[chan];
  /* modulator */
  	OPLL_SLOT *SLOT = &CH->SLOT[SLOT1];
  
  	ksl = v>>6; /* 0 / 1.5 / 3.0 / 6.0 dB/OCT */
  
  	SLOT->ksl = ksl ? 3-ksl : 31;
  	SLOT->TL  = (v&0x3f)<<(ENV_BITS-2-7); /* 7 bits TL (bit 6 = always 0) */
  	SLOT->TLL = SLOT->TL + (CH->ksl_base>>SLOT->ksl);
  }
  
  /* set ksl , waveforms, feedback */
  static INLINE void set_ksl_wave_fb(YM2413 *chip,int chan,int v)
  {
  	int ksl;
  	OPLL_CH   *CH   = &chip->P_CH[chan];
  /* modulator */
  	OPLL_SLOT *SLOT = &CH->SLOT[SLOT1];
  	SLOT->wavetable = ((v&0x08)>>3)*SIN_LEN;
  	SLOT->fb_shift  = (v&7) ? (v&7) + 8 : 0;
  
  /*carrier*/
  	SLOT = &CH->SLOT[SLOT2];
  	ksl = v>>6; /* 0 / 1.5 / 3.0 / 6.0 dB/OCT */
  
  	SLOT->ksl = ksl ? 3-ksl : 31;
  	SLOT->TLL = SLOT->TL + (CH->ksl_base>>SLOT->ksl);
  
  	SLOT->wavetable = ((v&0x10)>>4)*SIN_LEN;
  }
  
  /* set attack rate & decay rate  */
  static INLINE void set_ar_dr(YM2413 *chip,int slot,int v)
  {
  	OPLL_CH   *CH   = &chip->P_CH[slot/2];
  	OPLL_SLOT *SLOT = &CH->SLOT[slot&1];
  
  	SLOT->ar = (v>>4)  ? 16 + ((v>>4)  <<2) : 0;
  
  	if ((SLOT->ar + SLOT->ksr) < 16+62)
  	{
  		SLOT->eg_sh_ar  = eg_rate_shift [SLOT->ar + SLOT->ksr ];
  		SLOT->eg_sel_ar = eg_rate_select[SLOT->ar + SLOT->ksr ];
  	}
  	else
  	{
  		SLOT->eg_sh_ar  = 0;
  		SLOT->eg_sel_ar = 13*RATE_STEPS;
  	}
  
  	SLOT->dr    = (v&0x0f)? 16 + ((v&0x0f)<<2) : 0;
  	SLOT->eg_sh_dr  = eg_rate_shift [SLOT->dr + SLOT->ksr ];
  	SLOT->eg_sel_dr = eg_rate_select[SLOT->dr + SLOT->ksr ];
  }
  
  /* set sustain level & release rate */
  static INLINE void set_sl_rr(YM2413 *chip,int slot,int v)
  {
  	OPLL_CH   *CH   = &chip->P_CH[slot/2];
  	OPLL_SLOT *SLOT = &CH->SLOT[slot&1];
  
  	SLOT->sl  = sl_tab[ v>>4 ];
  
  	SLOT->rr  = (v&0x0f)? 16 + ((v&0x0f)<<2) : 0;
  	SLOT->eg_sh_rr  = eg_rate_shift [SLOT->rr + SLOT->ksr ];
  	SLOT->eg_sel_rr = eg_rate_select[SLOT->rr + SLOT->ksr ];
  }
  
  static void load_instrument(YM2413 *chip, UINT32 chan, UINT32 slot, UINT8* inst )
  {
  	set_mul			(chip, slot,   inst[0]);
  	set_mul			(chip, slot+1, inst[1]);
  	set_ksl_tl		(chip, chan,   inst[2]);
  	set_ksl_wave_fb	(chip, chan,   inst[3]);
  	set_ar_dr		(chip, slot,   inst[4]);
  	set_ar_dr		(chip, slot+1, inst[5]);
  	set_sl_rr		(chip, slot,   inst[6]);
  	set_sl_rr		(chip, slot+1, inst[7]);
  }
  static void update_instrument_zero(YM2413 *chip, UINT8 r )
  {
  	UINT8* inst = &chip->inst_tab[0][0]; /* point to user instrument */
  	UINT32 chan;
  	UINT32 chan_max;
  
  	chan_max = 9;
  	if (chip->rhythm & 0x20)
  		chan_max=6;
  
  	switch(r)
  	{
  	case 0:
  		for (chan=0; chan<chan_max; chan++)
  		{
  			if ((chip->instvol_r[chan]&0xf0)==0)
  			{
  				set_mul			(chip, chan*2, inst[0]);
  			}
  		}
          break;
  	case 1:
  		for (chan=0; chan<chan_max; chan++)
  		{
  			if ((chip->instvol_r[chan]&0xf0)==0)
  			{
  				set_mul			(chip, chan*2+1,inst[1]);
  			}
  		}
          break;
  	case 2:
  		for (chan=0; chan<chan_max; chan++)
  		{
  			if ((chip->instvol_r[chan]&0xf0)==0)
  			{
  				set_ksl_tl		(chip, chan,   inst[2]);
  			}
  		}
          break;
  	case 3:
  		for (chan=0; chan<chan_max; chan++)
  		{
  			if ((chip->instvol_r[chan]&0xf0)==0)
  			{
  				set_ksl_wave_fb	(chip, chan,   inst[3]);
  			}
  		}
          break;
  	case 4:
  		for (chan=0; chan<chan_max; chan++)
  		{
  			if ((chip->instvol_r[chan]&0xf0)==0)
  			{
  				set_ar_dr		(chip, chan*2, inst[4]);
  			}
  		}
          break;
  	case 5:
  		for (chan=0; chan<chan_max; chan++)
  		{
  			if ((chip->instvol_r[chan]&0xf0)==0)
  			{
  				set_ar_dr		(chip, chan*2+1,inst[5]);
  			}
  		}
          break;
  	case 6:
  		for (chan=0; chan<chan_max; chan++)
  		{
  			if ((chip->instvol_r[chan]&0xf0)==0)
  			{
  				set_sl_rr		(chip, chan*2, inst[6]);
  			}
  		}
          break;
  	case 7:
  		for (chan=0; chan<chan_max; chan++)
  		{
  			if ((chip->instvol_r[chan]&0xf0)==0)
  			{
  				set_sl_rr		(chip, chan*2+1,inst[7]);
  			}
  		}
          break;
      }
  }
  
  /* write a value v to register r on chip chip */
  static void OPLLWriteReg(YM2413 *chip, int r, int v)
  {
  	OPLL_CH *CH;
  	OPLL_SLOT *SLOT;
  	UINT8 *inst;
  	int chan;
  	int slot;
  
  	/* adjust bus to 8 bits */
  	r &= 0xff;
  	v &= 0xff;
  
  
  #ifdef LOG_CYM_FILE
  	if ((cymfile) && (r!=8) )
  	{
  		fputc( (unsigned char)r, cymfile );
  		fputc( (unsigned char)v, cymfile );
  	}
  #endif
  
  
  	switch(r&0xf0)
  	{
  	case 0x00:	/* 00-0f:control */
  	{
  		switch(r&0x0f)
  		{
  		case 0x00:	/* AM/VIB/EGTYP/KSR/MULTI (modulator) */
  		case 0x01:	/* AM/VIB/EGTYP/KSR/MULTI (carrier) */
  		case 0x02:	/* Key Scale Level, Total Level (modulator) */
  		case 0x03:	/* Key Scale Level, carrier waveform, modulator waveform, Feedback */
  		case 0x04:	/* Attack, Decay (modulator) */
  		case 0x05:	/* Attack, Decay (carrier) */
  		case 0x06:	/* Sustain, Release (modulator) */
  		case 0x07:	/* Sustain, Release (carrier) */
  			chip->inst_tab[0][r & 0x07] = v;
  			update_instrument_zero(chip,r&7);
  		break;
  
  		case 0x0e:	/* x, x, r,bd,sd,tom,tc,hh */
  		{
  			if(v&0x20)
  			{
  				if ((chip->rhythm&0x20)==0)
  				/*rhythm off to on*/
  				{
  					log_cb(RETRO_LOG_DEBUG, LOGPRE "YM2413: Rhythm mode enable\n");
  
  	/* Load instrument settings for channel seven(chan=6 since we're zero based). (Bass drum) */
  					chan = 6;
  					inst = &chip->inst_tab[16][0];
  					slot = chan*2;
  
  					load_instrument(chip, chan, slot, inst);
  
  	/* Load instrument settings for channel eight. (High hat and snare drum) */
  					chan = 7;
  					inst = &chip->inst_tab[17][0];
  					slot = chan*2;
  
  					load_instrument(chip, chan, slot, inst);
  
  					CH   = &chip->P_CH[chan];
  					SLOT = &CH->SLOT[SLOT1]; /* modulator envelope is HH */
  					SLOT->TL  = ((chip->instvol_r[chan]>>4)<<2)<<(ENV_BITS-2-7); /* 7 bits TL (bit 6 = always 0) */
  					SLOT->TLL = SLOT->TL + (CH->ksl_base>>SLOT->ksl);
  
  	/* Load instrument settings for channel nine. (Tom-tom and top cymbal) */
  					chan = 8;
  					inst = &chip->inst_tab[18][0];
  					slot = chan*2;
  
  					load_instrument(chip, chan, slot, inst);
  
  					CH   = &chip->P_CH[chan];
  					SLOT = &CH->SLOT[SLOT1]; /* modulator envelope is TOM */
  					SLOT->TL  = ((chip->instvol_r[chan]>>4)<<2)<<(ENV_BITS-2-7); /* 7 bits TL (bit 6 = always 0) */
  					SLOT->TLL = SLOT->TL + (CH->ksl_base>>SLOT->ksl);
  				}
  				/* BD key on/off */
  				if(v&0x10)
  				{
  					KEY_ON (&chip->P_CH[6].SLOT[SLOT1], 2);
  					KEY_ON (&chip->P_CH[6].SLOT[SLOT2], 2);
  				}
  				else
  				{
  					KEY_OFF(&chip->P_CH[6].SLOT[SLOT1],~2);
  					KEY_OFF(&chip->P_CH[6].SLOT[SLOT2],~2);
  				}
  				/* HH key on/off */
  				if(v&0x01) KEY_ON (&chip->P_CH[7].SLOT[SLOT1], 2);
  				else       KEY_OFF(&chip->P_CH[7].SLOT[SLOT1],~2);
  				/* SD key on/off */
  				if(v&0x08) KEY_ON (&chip->P_CH[7].SLOT[SLOT2], 2);
  				else       KEY_OFF(&chip->P_CH[7].SLOT[SLOT2],~2);
  				/* TOM key on/off */
  				if(v&0x04) KEY_ON (&chip->P_CH[8].SLOT[SLOT1], 2);
  				else       KEY_OFF(&chip->P_CH[8].SLOT[SLOT1],~2);
  				/* TOP-CY key on/off */
  				if(v&0x02) KEY_ON (&chip->P_CH[8].SLOT[SLOT2], 2);
  				else       KEY_OFF(&chip->P_CH[8].SLOT[SLOT2],~2);
  			}
  			else
  			{
  				if ((chip->rhythm&0x20)==1)
  				/*rhythm on to off*/
  				{
  					log_cb(RETRO_LOG_DEBUG, LOGPRE "YM2413: Rhythm mode disable\n");
  	/* Load instrument settings for channel seven(chan=6 since we're zero based).*/
  					chan = 6;
  					inst = &chip->inst_tab[chip->instvol_r[chan]>>4][0];
  					slot = chan*2;
  
  					load_instrument(chip, chan, slot, inst);
  
  	/* Load instrument settings for channel eight.*/
  					chan = 7;
  					inst = &chip->inst_tab[chip->instvol_r[chan]>>4][0];
  					slot = chan*2;
  
  					load_instrument(chip, chan, slot, inst);
  
  	/* Load instrument settings for channel nine.*/
  					chan = 8;
  					inst = &chip->inst_tab[chip->instvol_r[chan]>>4][0];
  					slot = chan*2;
  
  					load_instrument(chip, chan, slot, inst);
  				}
  				/* BD key off */
  				KEY_OFF(&chip->P_CH[6].SLOT[SLOT1],~2);
  				KEY_OFF(&chip->P_CH[6].SLOT[SLOT2],~2);
  				/* HH key off */
  				KEY_OFF(&chip->P_CH[7].SLOT[SLOT1],~2);
  				/* SD key off */
  				KEY_OFF(&chip->P_CH[7].SLOT[SLOT2],~2);
  				/* TOM key off */
  				KEY_OFF(&chip->P_CH[8].SLOT[SLOT1],~2);
  				/* TOP-CY off */
  				KEY_OFF(&chip->P_CH[8].SLOT[SLOT2],~2);
  			}
  			chip->rhythm  = v&0x3f;
  		}
  		break;
  		}
  	}
  	break;
  
  	case 0x10:
  	case 0x20:
  	{
  		int block_fnum;
  
  		chan = r&0x0f;
  
  		if (chan >= 9)
  			chan -= 9;	/* verified on real YM2413 */
  
  		CH = &chip->P_CH[chan];
  
  		if(r&0x10)
  		{	/* 10-18: FNUM 0-7 */
  			block_fnum  = (CH->block_fnum&0x0f00) | v;
  		}
  		else
  		{	/* 20-28: suson, keyon, block, FNUM 8 */
  			block_fnum = ((v&0x0f)<<8) | (CH->block_fnum&0xff);
  
  			if(v&0x10)
  			{
  				KEY_ON (&CH->SLOT[SLOT1], 1);
  				KEY_ON (&CH->SLOT[SLOT2], 1);
  			}
  			else
  			{
  				KEY_OFF(&CH->SLOT[SLOT1],~1);
  				KEY_OFF(&CH->SLOT[SLOT2],~1);
  			}
  
  
  			if (CH->sus!=(v&0x20))
  				log_cb(RETRO_LOG_DEBUG, LOGPRE "chan=%i sus=%2x\n",chan,v&0x20);
  
  			CH->sus = v & 0x20;
  		}
  		/* update */
  		if(CH->block_fnum != block_fnum)
  		{
  			UINT8 block;
  
  			CH->block_fnum = block_fnum;
  
  			/* BLK 2,1,0 bits -> bits 3,2,1 of kcode, FNUM MSB -> kcode LSB */
  			CH->kcode    = (block_fnum&0x0f00)>>8;
  
  			CH->ksl_base = ksl_tab[block_fnum>>5];
  
  			block_fnum   = block_fnum * 2;
  			block        = (block_fnum&0x1c00) >> 10;
  			CH->fc       = chip->fn_tab[block_fnum&0x03ff] >> (7-block);
  
  			/* refresh Total Level in both SLOTs of this channel */
  			CH->SLOT[SLOT1].TLL = CH->SLOT[SLOT1].TL + (CH->ksl_base>>CH->SLOT[SLOT1].ksl);
  			CH->SLOT[SLOT2].TLL = CH->SLOT[SLOT2].TL + (CH->ksl_base>>CH->SLOT[SLOT2].ksl);
  
  			/* refresh frequency counter in both SLOTs of this channel */
  			CALC_FCSLOT(CH,&CH->SLOT[SLOT1]);
  			CALC_FCSLOT(CH,&CH->SLOT[SLOT2]);
  		}
  	}
  	break;
  
  	case 0x30:	/* inst 4 MSBs, VOL 4 LSBs */
  	{
  		UINT8 old_instvol;
  
  		chan = r&0x0f;
  
  		if (chan >= 9)
  			chan -= 9;	/* verified on real YM2413 */
  
  		old_instvol = chip->instvol_r[chan];
  		chip->instvol_r[chan] = v;	/* store for later use */
  
  		CH   = &chip->P_CH[chan];
  		SLOT = &CH->SLOT[SLOT2]; /* carrier */
  		SLOT->TL  = ((v&0x0f)<<2)<<(ENV_BITS-2-7); /* 7 bits TL (bit 6 = always 0) */
  		SLOT->TLL = SLOT->TL + (CH->ksl_base>>SLOT->ksl);
  
  
  		/*check wether we are in rhythm mode and handle instrument/volume register accordingly*/
  		if ((chan>=6) && (chip->rhythm&0x20))
  		{
  			/* we're in rhythm mode*/
  
  			if (chan>=7) /* only for channel 7 and 8 (channel 6 is handled in usual way)*/
  			{
  				SLOT = &CH->SLOT[SLOT1]; /* modulator envelope is HH(chan=7) or TOM(chan=8) */
  				SLOT->TL  = ((chip->instvol_r[chan]>>4)<<2)<<(ENV_BITS-2-7); /* 7 bits TL (bit 6 = always 0) */
  				SLOT->TLL = SLOT->TL + (CH->ksl_base>>SLOT->ksl);
  			}
  		}
  		else
  		{
  			if ( (old_instvol&0xf0) == (v&0xf0) )
  				return;
  
  			inst = &chip->inst_tab[chip->instvol_r[chan]>>4][0];
  			slot = chan*2;
  
  			load_instrument(chip, chan, slot, inst);
  
  			log_cb(RETRO_LOG_DEBUG, LOGPRE "YM2413: chan#%02i inst=%02i:  (r=%2x, v=%2x)\n",chan,v>>4,r,v);
  			log_cb(RETRO_LOG_DEBUG, LOGPRE "  0:%2x  1:%2x\n",inst[0],inst[1]);	logerror("  2:%2x  3:%2x\n",inst[2],inst[3]);
  			log_cb(RETRO_LOG_DEBUG, LOGPRE "  4:%2x  5:%2x\n",inst[4],inst[5]);	logerror("  6:%2x  7:%2x\n",inst[6],inst[7]);
  		}
  	}
  	break;
  
  	default:
  	break;
  	}
  }
  
  #ifdef LOG_CYM_FILE
  static void cymfile_callback (int n)
  {
  	if (cymfile)
  	{
  		fputc( (unsigned char)8, cymfile );
  	}
  }
  #endif
  
  /* lock/unlock for common table */
  static int OPLL_LockTable(void)
  {
  	num_lock++;
  	if(num_lock>1) return 0;
  
  	/* first time */
  
  	cur_chip = NULL;
  	/* allocate total level table (128kb space) */
  	if( !init_tables() )
  	{
  		num_lock--;
  		return -1;
  	}
  
  #ifdef LOG_CYM_FILE
  	cymfile = fopen("2413_.cym","wb");
  	if (cymfile)
  		timer_pulse ( TIME_IN_HZ(110), 0, cymfile_callback); /*110 Hz pulse timer*/
  	else
  		log_cb(RETRO_LOG_DEBUG, LOGPRE "Could not create file 2413_.cym\n");
  #endif
  
  	return 0;
  }
  
  static void OPLL_UnLockTable(void)
  {
  	if(num_lock) num_lock--;
  	if(num_lock) return;
  
  	/* last time */
  
  	cur_chip = NULL;
  	OPLCloseTable();
  
  #ifdef LOG_CYM_FILE
  	fclose (cymfile);
  	cymfile = NULL;
  #endif
  
  }
  
  static void OPLLResetChip(YM2413 *chip)
  {
  	int c,s;
  	int i;
  
  	chip->eg_timer = 0;
  	chip->eg_cnt   = 0;
  
  	chip->noise_rng = 1;	/* noise shift register */
  
  
  	/* setup instruments table */
  	for (i=0; i<19; i++)
  	{
  		for (c=0; c<8; c++)
  		{
  			chip->inst_tab[i][c] = table[i][c];
  		}
  	}
  
  
  	/* reset with register write */
  	OPLLWriteReg(chip,0x0f,0); /*test reg*/
  	for(i = 0x3f ; i >= 0x10 ; i-- ) OPLLWriteReg(chip,i,0x00);
  
  	/* reset operator parameters */
  	for( c = 0 ; c < 9 ; c++ )
  	{
  		OPLL_CH *CH = &chip->P_CH[c];
  		for(s = 0 ; s < 2 ; s++ )
  		{
  			/* wave table */
  			CH->SLOT[s].wavetable = 0;
  			CH->SLOT[s].state     = EG_OFF;
  			CH->SLOT[s].volume    = MAX_ATT_INDEX;
  		}
  	}
  }
  
  /* Create one of virtual YM2413 */
  /* 'clock' is chip clock in Hz  */
  /* 'rate'  is sampling rate  */
  static YM2413 *OPLLCreate(int clock, int rate)
  {
  	char *ptr;
  	YM2413 *chip;
  	int state_size;
  
  	if (OPLL_LockTable() ==-1) return NULL;
  
  	/* calculate chip state size */
  	state_size  = sizeof(YM2413);
  
  	/* allocate memory block */
  	ptr = malloc(state_size);
  
  	if (ptr==NULL)
  		return NULL;
  
  	/* clear */
  	memset(ptr,0,state_size);
  
  	chip  = (YM2413 *)ptr;
  
  	chip->clock = clock;
  	chip->rate  = rate;
  
  	/* init global tables */
  	OPLL_initalize(chip);
  
  	/* reset chip */
  	OPLLResetChip(chip);
  	return chip;
  }
  
  /* Destroy one of virtual YM3812 */
  static void OPLLDestroy(YM2413 *chip)
  {
  	OPLL_UnLockTable();
  	free(chip);
  }
  
  /* Option handlers */
  
  static void OPLLSetUpdateHandler(YM2413 *chip,OPLL_UPDATEHANDLER UpdateHandler,int param)
  {
  	chip->UpdateHandler = UpdateHandler;
  	chip->UpdateParam = param;
  }
  
  /* YM3812 I/O interface */
  static void OPLLWrite(YM2413 *chip,int a,int v)
  {
  	if( !(a&1) )
  	{	/* address port */
  		chip->address = v & 0xff;
  	}
  	else
  	{	/* data port */
  		if(chip->UpdateHandler) chip->UpdateHandler(chip->UpdateParam,0);
  		OPLLWriteReg(chip,chip->address,v);
  	}
  }
  
  static unsigned char OPLLRead(YM2413 *chip,int a)
  {
  	if( !(a&1) )
  	{
  		/* status port */
  		return chip->status;
  	}
  	return 0xff;
  }
  
  
  
  
  
  #define MAX_OPLL_CHIPS 4
  
  
  static YM2413 *OPLL_YM2413[MAX_OPLL_CHIPS];	/* array of pointers to the YM2413's */
  static int YM2413NumChips = 0;				/* number of chips */
  
  int YM2413Init(int num, int clock, int rate)
  {
  	int i;
  
  	if (YM2413NumChips)
  		return -1;	/* duplicate init. */
  
  	YM2413NumChips = num;
  
  	for (i = 0;i < YM2413NumChips; i++)
  	{
  		/* emulator create */
  		OPLL_YM2413[i] = OPLLCreate(clock, rate);
  		if(OPLL_YM2413[i] == NULL)
  		{
  			/* it's really bad - we run out of memeory */
  			YM2413NumChips = 0;
  			return -1;
  		}
  	}
  
  	return 0;
  }
  
  void YM2413Shutdown(void)
  {
  	int i;
  
  	for (i = 0;i < YM2413NumChips; i++)
  	{
  		/* emulator shutdown */
  		OPLLDestroy(OPLL_YM2413[i]);
  		OPLL_YM2413[i] = NULL;
  	}
  	YM2413NumChips = 0;
  }
  
  void YM2413ResetChip(int which)
  {
  	OPLLResetChip(OPLL_YM2413[which]);
  }
  
  void YM2413Write(int which, int a, int v)
  {
  	OPLLWrite(OPLL_YM2413[which], a, v);
  }
  
  unsigned char YM2413Read(int which, int a)
  {
  	return OPLLRead(OPLL_YM2413[which], a) & 0x03 ;
  }
  
  void YM2413SetUpdateHandler(int which,OPLL_UPDATEHANDLER UpdateHandler,int param)
  {
  	OPLLSetUpdateHandler(OPLL_YM2413[which], UpdateHandler, param);
  }
  
  
  /*
  ** Generate samples for one of the YM2413's
  **
  ** 'which' is the virtual YM2413 number
  ** '*buffer' is the output buffer pointer
  ** 'length' is the number of samples that should be generated
  */
  void YM2413UpdateOne(int which, INT16 **buffers, int length)
  {
  	YM2413		*chip  = OPLL_YM2413[which];
  	UINT8		rhythm = chip->rhythm&0x20;
  	SAMP		*bufMO = buffers[0];
  	SAMP		*bufRO = buffers[1];
  
  	int i;
  
  	if( (void *)chip != cur_chip ){
  		cur_chip = (void *)chip;
  		/* rhythm slots */
  		SLOT7_1 = &chip->P_CH[7].SLOT[SLOT1];
  		SLOT7_2 = &chip->P_CH[7].SLOT[SLOT2];
  		SLOT8_1 = &chip->P_CH[8].SLOT[SLOT1];
  		SLOT8_2 = &chip->P_CH[8].SLOT[SLOT2];
  	}
  
  
  	for( i=0; i < length ; i++ )
  	{
  		int mo,ro;
  
  		output[0] = 0;
  		output[1] = 0;
  
  		advance_lfo(chip);
  
  		/* FM part */
  		chan_calc(&chip->P_CH[0]);
  /*SAVE_SEPARATE_CHANNEL(0);*/
  		chan_calc(&chip->P_CH[1]);
  		chan_calc(&chip->P_CH[2]);
  		chan_calc(&chip->P_CH[3]);
  		chan_calc(&chip->P_CH[4]);
  		chan_calc(&chip->P_CH[5]);
  
  		if(!rhythm)
  		{
  			chan_calc(&chip->P_CH[6]);
  			chan_calc(&chip->P_CH[7]);
  			chan_calc(&chip->P_CH[8]);
  		}
  		else		/* Rhythm part */
  		{
  			rhythm_calc(&chip->P_CH[0], (chip->noise_rng>>0)&1 );
  		}
  
  		mo = output[0];
  		ro = output[1];
  
  		mo >>= FINAL_SH;
  		ro >>= FINAL_SH;
  
        MAME_CLAMP_SAMPLE(mo);
        MAME_CLAMP_SAMPLE(ro);
  
  		#ifdef SAVE_SAMPLE
  		if (which==0)
  		{
  			SAVE_ALL_CHANNELS
  		}
  		#endif
  
  		/* store to sound buffer */
  		bufMO[i] = mo;
  		bufRO[i] = ro;
  
  		advance(chip);
  	}
  
  }
  