[picodrive.git] / Pico / cd / Pico.c

// This is part of Pico Library

// (c) Copyright 2004 Dave, All rights reserved.
// (c) Copyright 2007 notaz, All rights reserved.
// Free for non-commercial use.

// For commercial use, separate licencing terms must be obtained.


#include "../PicoInt.h"
#include "../sound/sound.h"


extern unsigned char formatted_bram[4*0x10];


int PicoInitMCD(void)
{
  SekInitS68k();
  Init_CD_Driver();

  return 0;
}


void PicoExitMCD(void)
{
  End_CD_Driver();
}

int PicoResetMCD(int hard)
{
  memset(Pico_mcd->prg_ram,    0, sizeof(Pico_mcd->prg_ram));
  memset(Pico_mcd->word_ram2M, 0, sizeof(Pico_mcd->word_ram2M));
  memset(Pico_mcd->pcm_ram,    0, sizeof(Pico_mcd->pcm_ram));
  if (hard) {
	  int fmt_size = sizeof(formatted_bram);
	  memset(Pico_mcd->bram, 0, sizeof(Pico_mcd->bram));
	  memcpy(Pico_mcd->bram + sizeof(Pico_mcd->bram) - fmt_size, formatted_bram, fmt_size);
  }
  memset(Pico_mcd->s68k_regs, 0, sizeof(Pico_mcd->s68k_regs));
  memset(&Pico_mcd->pcm, 0, sizeof(Pico_mcd->pcm));

  *(unsigned int *)(Pico_mcd->bios + 0x70) = 0xffffffff; // reset hint vector (simplest way to implement reg6)
  Pico_mcd->m.state_flags |= 2; // s68k reset pending
  Pico_mcd->s68k_regs[3] = 1; // 2M word RAM mode with m68k access after reset
  Pico_mcd->m.counter75hz = 0;

  LC89510_Reset();
  Reset_CD();
  gfx_cd_reset();
#ifdef _ASM_CD_MEMORY_C
  PicoMemResetCD(1);
#endif

  return 0;
}

static __inline void SekRun(int cyc)
{
  int cyc_do;
  SekCycleAim+=cyc;
  if((cyc_do=SekCycleAim-SekCycleCnt) < 0) return;
#if defined(EMU_C68K)
  PicoCpu.cycles=cyc_do;
  CycloneRun(&PicoCpu);
  SekCycleCnt+=cyc_do-PicoCpu.cycles;
#elif defined(EMU_M68K)
  m68k_set_context(&PicoM68kCPU);
  SekCycleCnt+=m68k_execute(cyc_do);
#endif
}

static __inline void SekRunS68k(int cyc)
{
  int cyc_do;
  SekCycleAimS68k+=cyc;
  if((cyc_do=SekCycleAimS68k-SekCycleCntS68k) < 0) return;
#if defined(EMU_C68K)
  PicoCpuS68k.cycles=cyc_do;
  CycloneRun(&PicoCpuS68k);
  SekCycleCntS68k+=cyc_do-PicoCpuS68k.cycles;
#elif defined(EMU_M68K)
  m68k_set_context(&PicoS68kCPU);
  SekCycleCntS68k+=m68k_execute(cyc_do);
#endif
}

#define PS_STEP_M68K ((488<<16)/20) // ~24
//#define PS_STEP_S68K 13

#ifndef _ASM_CD_PICO_C
static __inline void SekRunPS(int cyc_m68k, int cyc_s68k)
{
  int cycn, cycn_s68k, cyc_do;
  int d_cm = 0, d_cs = 0, ex;
  SekCycleAim+=cyc_m68k;
  SekCycleAimS68k+=cyc_s68k;

//  fprintf(stderr, "=== start %3i/%3i [%3i/%3i] {%05i.%i} ===\n", cyc_m68k, cyc_s68k,
//  		SekCycleAim-SekCycleCnt, SekCycleAimS68k-SekCycleCntS68k, Pico.m.frame_count, Pico.m.scanline);

  /* loop 488 downto 0 in steps of PS_STEP */
  for (cycn = (488<<16)-PS_STEP_M68K; cycn >= 0; cycn -= PS_STEP_M68K)
  {
    ex = 0;
    cycn_s68k = (cycn + cycn/2 + cycn/8) >> 16;
//fprintf(stderr, "%3i/%3i:  ", cycn>>16, cycn_s68k);
    if ((cyc_do = SekCycleAim-SekCycleCnt-(cycn>>16)) > 0) {
#if defined(EMU_C68K)
      PicoCpu.cycles = cyc_do;
      CycloneRun(&PicoCpu);
      SekCycleCnt += cyc_do - PicoCpu.cycles;
#elif defined(EMU_M68K)
      m68k_set_context(&PicoM68kCPU);
      SekCycleCnt += (ex = m68k_execute(cyc_do));
#endif
    }
//fprintf(stderr, "%3i ", ex); d_cm += ex; ex = 0;
    if ((cyc_do = SekCycleAimS68k-SekCycleCntS68k-cycn_s68k) > 0) {
#if defined(EMU_C68K)
      PicoCpuS68k.cycles = cyc_do;
      CycloneRun(&PicoCpuS68k);
      SekCycleCntS68k += cyc_do - PicoCpuS68k.cycles;
#elif defined(EMU_M68K)
      m68k_set_context(&PicoS68kCPU);
      SekCycleCntS68k += (ex = m68k_execute(cyc_do));
#endif
    }
//fprintf(stderr, "%3i\n", ex); d_cs += ex;
  }

//fprintf(stderr, "==    end %3i/%3i    ==\n", d_cm, d_cs);
}
#else
void SekRunPS(int cyc_m68k, int cyc_s68k);
#endif


static __inline void check_cd_dma(void)
{
	int ddx;

	if (!(Pico_mcd->scd.Status_CDC & 0x08)) return;

	ddx = Pico_mcd->s68k_regs[4] & 7;
	if (ddx <  2) return; // invalid
	if (ddx <  4) {
		Pico_mcd->s68k_regs[4] |= 0x40; // Data set ready in host port
		return;
	}
	if (ddx == 6) return; // invalid

	Update_CDC_TRansfer(ddx); // now go and do the actual transfer
}

static __inline void update_chips(void)
{
	int counter_timer, int3_set;
	int counter75hz_lim = Pico.m.pal ? 2080 : 2096;

	// 75Hz CDC update
	if ((Pico_mcd->m.counter75hz+=10) >= counter75hz_lim) {
		Pico_mcd->m.counter75hz -= counter75hz_lim;
		Check_CD_Command();
	}

	// update timers
	counter_timer = Pico.m.pal ? 0x21630 : 0x2121c; // 136752 : 135708;
	Pico_mcd->m.timer_stopwatch += counter_timer;
	if ((int3_set = Pico_mcd->s68k_regs[0x31])) {
		Pico_mcd->m.timer_int3 -= counter_timer;
		if (Pico_mcd->m.timer_int3 < 0) {
			if (Pico_mcd->s68k_regs[0x33] & (1<<3)) {
				dprintf("s68k: timer irq 3");
				SekInterruptS68k(3);
				Pico_mcd->m.timer_int3 += int3_set << 16;
			}
			// is this really what happens if irq3 is masked out?
			Pico_mcd->m.timer_int3 &= 0xffffff;
		}
	}

	// update gfx chip
	if (Pico_mcd->rot_comp.Reg_58 & 0x8000)
		gfx_cd_update();
}


static int PicoFrameHintsMCD(void)
{
  struct PicoVideo *pv=&Pico.video;
  int total_z80=0,lines,y,lines_vis = 224,z80CycleAim = 0,line_sample;
  const int cycles_68k=488,cycles_z80=228,cycles_s68k=795; // both PAL and NTSC compile to same values
  int skip=PicoSkipFrame || (PicoOpt&0x10);
  int hint; // Hint counter

  if(Pico.m.pal) { //
    //cycles_68k = (int) ((double) OSC_PAL  /  7 / 50 / 312 + 0.4); // should compile to a constant (488)
    //cycles_z80 = (int) ((double) OSC_PAL  / 15 / 50 / 312 + 0.4); // 228
    lines  = 312;    // Steve Snake says there are 313 lines, but this seems to also work well
    line_sample = 68;
    if(pv->reg[1]&8) lines_vis = 240;
  } else {
    //cycles_68k = (int) ((double) OSC_NTSC /  7 / 60 / 262 + 0.4); // 488
    //cycles_z80 = (int) ((double) OSC_NTSC / 15 / 60 / 262 + 0.4); // 228
    lines  = 262;
    line_sample = 93;
  }

  SekCyclesReset();
  SekCyclesResetS68k();
  //z80ExtraCycles = 0;

  if(PicoOpt&4)
    z80CycleAim = 0;
//    z80_resetCycles();

  pv->status&=~0x88; // clear V-Int, come out of vblank

  hint=pv->reg[10]; // Load H-Int counter
  //dprintf("-hint: %i", hint);

  for (y=0;y<lines;y++)
  {
    Pico.m.scanline=(short)y;

    // pad delay (for 6 button pads)
    if(PicoOpt&0x20) {
      if(Pico.m.padDelay[0]++ > 25) Pico.m.padTHPhase[0]=0;
      if(Pico.m.padDelay[1]++ > 25) Pico.m.padTHPhase[1]=0;
    }

    check_cd_dma();

    // H-Interrupts:
    if(y <= lines_vis && --hint < 0) // y <= lines_vis: Comix Zone, Golden Axe
    {
      //dprintf("rhint:old @ %06x", SekPc);
      hint=pv->reg[10]; // Reload H-Int counter
      pv->pending_ints|=0x10;
      if (pv->reg[0]&0x10) SekInterrupt(4);
      //dprintf("rhint: %i @ %06x [%i|%i]", hint, SekPc, y, SekCycleCnt);
      //dprintf("hint_routine: %x", (*(unsigned short*)(Pico.ram+0x0B84)<<16)|*(unsigned short*)(Pico.ram+0x0B86));
    }

    // V-Interrupt:
    if (y == lines_vis)
    {
      //dprintf("vint: @ %06x [%i|%i]", SekPc, y, SekCycleCnt);
      pv->status|=0x88; // V-Int happened, go into vblank
      SekRun(128); SekCycleAim-=128; // there must be a gap between H and V ints, also after vblank bit set (Mazin Saga, Bram Stoker's Dracula)
      /*if(Pico.m.z80Run && (PicoOpt&4)) {
        z80CycleAim+=cycles_z80/2;
        total_z80+=z80_run(z80CycleAim-total_z80);
        z80CycleAim-=cycles_z80/2;
      }*/
      pv->pending_ints|=0x20;
      if(pv->reg[1]&0x20) SekInterrupt(6);
      if(Pico.m.z80Run && (PicoOpt&4)) // ?
        z80_int();
      //dprintf("zint: [%i|%i] zPC=%04x", Pico.m.scanline, SekCyclesDone(), mz80GetRegisterValue(NULL, 0));
    }

    // decide if we draw this line
#if CAN_HANDLE_240_LINES
    if(!skip && ((!(pv->reg[1]&8) && y<224) || ((pv->reg[1]&8) && y<240)) )
#else
    if(!skip && y<224)
#endif
      PicoLine(y);

    if(PicoOpt&1)
      sound_timers_and_dac(y);

    // get samples from sound chips
    if (y == 224 && PsndOut) {
      int len = sound_render(0, PsndLen);
      if (PicoWriteSound) PicoWriteSound(len);
      // clear sound buffer
      sound_clear();
    }

    // Run scanline:
      //dprintf("m68k starting exec @ %06x", SekPc);
    if(Pico.m.dma_bytes) SekCycleCnt+=CheckDMA();
    if((PicoOpt & 0x2000) && (Pico_mcd->m.busreq&3) == 1) {
      SekRunPS(cycles_68k, cycles_s68k); // "better/perfect sync"
    } else {
      SekRun(cycles_68k);
      if ((Pico_mcd->m.busreq&3) == 1) // no busreq/no reset
        SekRunS68k(cycles_s68k);
    }

    if((PicoOpt&4) && Pico.m.z80Run) {
      Pico.m.z80Run|=2;
      z80CycleAim+=cycles_z80;
      total_z80+=z80_run(z80CycleAim-total_z80);
    }

    update_chips();
  }

  // draw a frame just after vblank in alternative render mode
  if(!PicoSkipFrame && (PicoOpt&0x10))
    PicoFrameFull();

  return 0;
}


int PicoFrameMCD(void)
{
  if(!(PicoOpt&0x10))
    PicoFrameStart();

  PicoFrameHintsMCD();

  return 0;
}
Commit	Line	Data
cc68a136	1	// This is part of Pico Library
	2
	3	// (c) Copyright 2004 Dave, All rights reserved.
672ad671	4	// (c) Copyright 2007 notaz, All rights reserved.
cc68a136	5	// Free for non-commercial use.
	6
	7	// For commercial use, separate licencing terms must be obtained.
	8
	9
	10	#include "../PicoInt.h"
	11	#include "../sound/sound.h"
	12
	13
76276b0b	14	extern unsigned char formatted_bram[4*0x10];
cc68a136	15
	16
	17	int PicoInitMCD(void)
	18	{
	19	SekInitS68k();
	20	Init_CD_Driver();
	21
	22	return 0;
	23	}
	24
	25
	26	void PicoExitMCD(void)
	27	{
	28	End_CD_Driver();
	29	}
	30
	31	int PicoResetMCD(int hard)
	32	{
fa1e5e29	33	memset(Pico_mcd->prg_ram, 0, sizeof(Pico_mcd->prg_ram));
	34	memset(Pico_mcd->word_ram2M, 0, sizeof(Pico_mcd->word_ram2M));
	35	memset(Pico_mcd->pcm_ram, 0, sizeof(Pico_mcd->pcm_ram));
51a902ae	36	if (hard) {
76276b0b	37	int fmt_size = sizeof(formatted_bram);
51a902ae	38	memset(Pico_mcd->bram, 0, sizeof(Pico_mcd->bram));
76276b0b	39	memcpy(Pico_mcd->bram + sizeof(Pico_mcd->bram) - fmt_size, formatted_bram, fmt_size);
51a902ae	40	}
51a902ae	41	memset(Pico_mcd->s68k_regs, 0, sizeof(Pico_mcd->s68k_regs));
4f265db7	42	memset(&Pico_mcd->pcm, 0, sizeof(Pico_mcd->pcm));
51a902ae	43
d1df8786	44	(unsigned int )(Pico_mcd->bios + 0x70) = 0xffffffff; // reset hint vector (simplest way to implement reg6)
51a902ae	45	Pico_mcd->m.state_flags \|= 2; // s68k reset pending
672ad671	46	Pico_mcd->s68k_regs[3] = 1; // 2M word RAM mode with m68k access after reset
51a902ae	47	Pico_mcd->m.counter75hz = 0;
cc68a136	48
	49	LC89510_Reset();
	50	Reset_CD();
51a902ae	51	gfx_cd_reset();
4ff2d527	52	#ifdef _ASM_CD_MEMORY_C
	53	PicoMemResetCD(1);
	54	#endif
cc68a136	55
	56	return 0;
	57	}
	58
	59	static __inline void SekRun(int cyc)
	60	{
	61	int cyc_do;
	62	SekCycleAim+=cyc;
	63	if((cyc_do=SekCycleAim-SekCycleCnt) < 0) return;
b837b69b	64	#if defined(EMU_C68K)
	65	PicoCpu.cycles=cyc_do;
	66	CycloneRun(&PicoCpu);
	67	SekCycleCnt+=cyc_do-PicoCpu.cycles;
	68	#elif defined(EMU_M68K)
cc68a136	69	m68k_set_context(&PicoM68kCPU);
	70	SekCycleCnt+=m68k_execute(cyc_do);
	71	#endif
	72	}
	73
	74	static __inline void SekRunS68k(int cyc)
	75	{
	76	int cyc_do;
	77	SekCycleAimS68k+=cyc;
	78	if((cyc_do=SekCycleAimS68k-SekCycleCntS68k) < 0) return;
b837b69b	79	#if defined(EMU_C68K)
	80	PicoCpuS68k.cycles=cyc_do;
	81	CycloneRun(&PicoCpuS68k);
	82	SekCycleCntS68k+=cyc_do-PicoCpuS68k.cycles;
	83	#elif defined(EMU_M68K)
cc68a136	84	m68k_set_context(&PicoS68kCPU);
	85	SekCycleCntS68k+=m68k_execute(cyc_do);
	86	#endif
	87	}
	88
7336a99a	89	#define PS_STEP_M68K ((488<<16)/20) // ~24
7336a99a	90	//#define PS_STEP_S68K 13
68cba51e	91
7336a99a	92	#ifndef _ASM_CD_PICO_C
68cba51e	93	static __inline void SekRunPS(int cyc_m68k, int cyc_s68k)
68cba51e	94	{
7336a99a	95	int cycn, cycn_s68k, cyc_do;
7336a99a	96	int d_cm = 0, d_cs = 0, ex;
68cba51e	97	SekCycleAim+=cyc_m68k;
68cba51e	98	SekCycleAimS68k+=cyc_s68k;
7336a99a	99
	100	// fprintf(stderr, "=== start %3i/%3i [%3i/%3i] {%05i.%i} ===\n", cyc_m68k, cyc_s68k,
	101	// SekCycleAim-SekCycleCnt, SekCycleAimS68k-SekCycleCntS68k, Pico.m.frame_count, Pico.m.scanline);
	102
	103	/* loop 488 downto 0 in steps of PS_STEP */
	104	for (cycn = (488<<16)-PS_STEP_M68K; cycn >= 0; cycn -= PS_STEP_M68K)
	105	{
	106	ex = 0;
	107	cycn_s68k = (cycn + cycn/2 + cycn/8) >> 16;
	108	//fprintf(stderr, "%3i/%3i: ", cycn>>16, cycn_s68k);
	109	if ((cyc_do = SekCycleAim-SekCycleCnt-(cycn>>16)) > 0) {
68cba51e	110	#if defined(EMU_C68K)
7336a99a	111	PicoCpu.cycles = cyc_do;
68cba51e	112	CycloneRun(&PicoCpu);
7336a99a	113	SekCycleCnt += cyc_do - PicoCpu.cycles;
68cba51e	114	#elif defined(EMU_M68K)
68cba51e	115	m68k_set_context(&PicoM68kCPU);
7336a99a	116	SekCycleCnt += (ex = m68k_execute(cyc_do));
68cba51e	117	#endif
7336a99a	118	}
	119	//fprintf(stderr, "%3i ", ex); d_cm += ex; ex = 0;
	120	if ((cyc_do = SekCycleAimS68k-SekCycleCntS68k-cycn_s68k) > 0) {
68cba51e	121	#if defined(EMU_C68K)
7336a99a	122	PicoCpuS68k.cycles = cyc_do;
68cba51e	123	CycloneRun(&PicoCpuS68k);
7336a99a	124	SekCycleCntS68k += cyc_do - PicoCpuS68k.cycles;
68cba51e	125	#elif defined(EMU_M68K)
68cba51e	126	m68k_set_context(&PicoS68kCPU);
7336a99a	127	SekCycleCntS68k += (ex = m68k_execute(cyc_do));
68cba51e	128	#endif
7336a99a	129	}
7336a99a	130	//fprintf(stderr, "%3i\n", ex); d_cs += ex;
68cba51e	131	}
7336a99a	132
7336a99a	133	//fprintf(stderr, "== end %3i/%3i ==\n", d_cm, d_cs);
68cba51e	134	}
7336a99a	135	#else
	136	void SekRunPS(int cyc_m68k, int cyc_s68k);
	137	#endif
68cba51e	138
68cba51e	139
bf098bc5	140	static __inline void check_cd_dma(void)
	141	{
	142	int ddx;
	143
c459aefd	144	if (!(Pico_mcd->scd.Status_CDC & 0x08)) return;
bf098bc5	145
	146	ddx = Pico_mcd->s68k_regs[4] & 7;
	147	if (ddx < 2) return; // invalid
c459aefd	148	if (ddx < 4) {
	149	Pico_mcd->s68k_regs[4] \|= 0x40; // Data set ready in host port
	150	return;
	151	}
bf098bc5	152	if (ddx == 6) return; // invalid
	153
	154	Update_CDC_TRansfer(ddx); // now go and do the actual transfer
	155	}
	156
4f265db7	157	static __inline void update_chips(void)
	158	{
	159	int counter_timer, int3_set;
	160	int counter75hz_lim = Pico.m.pal ? 2080 : 2096;
	161
	162	// 75Hz CDC update
	163	if ((Pico_mcd->m.counter75hz+=10) >= counter75hz_lim) {
	164	Pico_mcd->m.counter75hz -= counter75hz_lim;
	165	Check_CD_Command();
	166	}
	167
	168	// update timers
	169	counter_timer = Pico.m.pal ? 0x21630 : 0x2121c; // 136752 : 135708;
	170	Pico_mcd->m.timer_stopwatch += counter_timer;
	171	if ((int3_set = Pico_mcd->s68k_regs[0x31])) {
	172	Pico_mcd->m.timer_int3 -= counter_timer;
	173	if (Pico_mcd->m.timer_int3 < 0) {
	174	if (Pico_mcd->s68k_regs[0x33] & (1<<3)) {
	175	dprintf("s68k: timer irq 3");
	176	SekInterruptS68k(3);
	177	Pico_mcd->m.timer_int3 += int3_set << 16;
	178	}
	179	// is this really what happens if irq3 is masked out?
	180	Pico_mcd->m.timer_int3 &= 0xffffff;
	181	}
	182	}
	183
	184	// update gfx chip
	185	if (Pico_mcd->rot_comp.Reg_58 & 0x8000)
	186	gfx_cd_update();
	187	}
	188
b837b69b	189
cc68a136	190	static int PicoFrameHintsMCD(void)
	191	{
	192	struct PicoVideo *pv=&Pico.video;
4f265db7	193	int total_z80=0,lines,y,lines_vis = 224,z80CycleAim = 0,line_sample;
cc68a136	194	const int cycles_68k=488,cycles_z80=228,cycles_s68k=795; // both PAL and NTSC compile to same values
	195	int skip=PicoSkipFrame \|\| (PicoOpt&0x10);
	196	int hint; // Hint counter
	197
	198	if(Pico.m.pal) { //
	199	//cycles_68k = (int) ((double) OSC_PAL / 7 / 50 / 312 + 0.4); // should compile to a constant (488)
	200	//cycles_z80 = (int) ((double) OSC_PAL / 15 / 50 / 312 + 0.4); // 228
	201	lines = 312; // Steve Snake says there are 313 lines, but this seems to also work well
	202	line_sample = 68;
	203	if(pv->reg[1]&8) lines_vis = 240;
	204	} else {
	205	//cycles_68k = (int) ((double) OSC_NTSC / 7 / 60 / 262 + 0.4); // 488
	206	//cycles_z80 = (int) ((double) OSC_NTSC / 15 / 60 / 262 + 0.4); // 228
	207	lines = 262;
	208	line_sample = 93;
	209	}
	210
	211	SekCyclesReset();
	212	SekCyclesResetS68k();
	213	//z80ExtraCycles = 0;
	214
	215	if(PicoOpt&4)
	216	z80CycleAim = 0;
	217	// z80_resetCycles();
	218
	219	pv->status&=~0x88; // clear V-Int, come out of vblank
	220
	221	hint=pv->reg[10]; // Load H-Int counter
	222	//dprintf("-hint: %i", hint);
	223
	224	for (y=0;y<lines;y++)
	225	{
	226	Pico.m.scanline=(short)y;
	227
	228	// pad delay (for 6 button pads)
	229	if(PicoOpt&0x20) {
	230	if(Pico.m.padDelay[0]++ > 25) Pico.m.padTHPhase[0]=0;
	231	if(Pico.m.padDelay[1]++ > 25) Pico.m.padTHPhase[1]=0;
	232	}
	233
bf098bc5	234	check_cd_dma();
bf098bc5	235
cc68a136	236	// H-Interrupts:
	237	if(y <= lines_vis && --hint < 0) // y <= lines_vis: Comix Zone, Golden Axe
	238	{
	239	//dprintf("rhint:old @ %06x", SekPc);
	240	hint=pv->reg[10]; // Reload H-Int counter
	241	pv->pending_ints\|=0x10;
	242	if (pv->reg[0]&0x10) SekInterrupt(4);
	243	//dprintf("rhint: %i @ %06x [%i\|%i]", hint, SekPc, y, SekCycleCnt);
	244	//dprintf("hint_routine: %x", ((unsigned short)(Pico.ram+0x0B84)<<16)\|(unsigned short)(Pico.ram+0x0B86));
	245	}
	246
	247	// V-Interrupt:
	248	if (y == lines_vis)
	249	{
	250	//dprintf("vint: @ %06x [%i\|%i]", SekPc, y, SekCycleCnt);
	251	pv->status\|=0x88; // V-Int happened, go into vblank
	252	SekRun(128); SekCycleAim-=128; // there must be a gap between H and V ints, also after vblank bit set (Mazin Saga, Bram Stoker's Dracula)
	253	/*if(Pico.m.z80Run && (PicoOpt&4)) {
	254	z80CycleAim+=cycles_z80/2;
	255	total_z80+=z80_run(z80CycleAim-total_z80);
	256	z80CycleAim-=cycles_z80/2;
	257	}*/
	258	pv->pending_ints\|=0x20;
	259	if(pv->reg[1]&0x20) SekInterrupt(6);
	260	if(Pico.m.z80Run && (PicoOpt&4)) // ?
	261	z80_int();
	262	//dprintf("zint: [%i\|%i] zPC=%04x", Pico.m.scanline, SekCyclesDone(), mz80GetRegisterValue(NULL, 0));
	263	}
	264
	265	// decide if we draw this line
	266	#if CAN_HANDLE_240_LINES
	267	if(!skip && ((!(pv->reg[1]&8) && y<224) \|\| ((pv->reg[1]&8) && y<240)) )
	268	#else
	269	if(!skip && y<224)
	270	#endif
	271	PicoLine(y);
	272
	273	if(PicoOpt&1)
	274	sound_timers_and_dac(y);
	275
	276	// get samples from sound chips
7a93adeb	277	if (y == 224 && PsndOut) {
	278	int len = sound_render(0, PsndLen);
	279	if (PicoWriteSound) PicoWriteSound(len);
	280	// clear sound buffer
	281	sound_clear();
	282	}
cc68a136	283
	284	// Run scanline:
	285	//dprintf("m68k starting exec @ %06x", SekPc);
672ad671	286	if(Pico.m.dma_bytes) SekCycleCnt+=CheckDMA();
68cba51e	287	if((PicoOpt & 0x2000) && (Pico_mcd->m.busreq&3) == 1) {
7336a99a	288	SekRunPS(cycles_68k, cycles_s68k); // "better/perfect sync"
68cba51e	289	} else {
	290	SekRun(cycles_68k);
	291	if ((Pico_mcd->m.busreq&3) == 1) // no busreq/no reset
	292	SekRunS68k(cycles_s68k);
cc68a136	293	}
	294
	295	if((PicoOpt&4) && Pico.m.z80Run) {
	296	Pico.m.z80Run\|=2;
	297	z80CycleAim+=cycles_z80;
	298	total_z80+=z80_run(z80CycleAim-total_z80);
	299	}
	300
4f265db7	301	update_chips();
cc68a136	302	}
	303
	304	// draw a frame just after vblank in alternative render mode
	305	if(!PicoSkipFrame && (PicoOpt&0x10))
	306	PicoFrameFull();
	307
	308	return 0;
	309	}
	310
	311
	312	int PicoFrameMCD(void)
	313	{
	314	if(!(PicoOpt&0x10))
	315	PicoFrameStart();
	316
	317	PicoFrameHintsMCD();
	318
	319	return 0;
	320	}
	321
	322