[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();

  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 8
#define PS_STEP_S68K 13

static __inline void SekRunPS(int cyc_m68k, int cyc_s68k)
{
  int cyc_do_m68k, cyc_do_s68k, it=0;
  int cyc_done_m68k=0, cyc_done_s68k=0;
  SekCycleAim+=cyc_m68k;
  SekCycleAimS68k+=cyc_s68k;
  cyc_do_m68k=SekCycleAim-SekCycleCnt;
  cyc_do_s68k=SekCycleAimS68k-SekCycleCntS68k;
  while (cyc_done_m68k < cyc_do_m68k || cyc_done_s68k < cyc_do_s68k) {
    it++;
    if (cyc_done_m68k < cyc_do_m68k && it*PS_STEP_M68K > cyc_done_m68k) {
#if defined(EMU_C68K)
      PicoCpu.cycles = PS_STEP_M68K;
      CycloneRun(&PicoCpu);
      cyc_done_m68k += PS_STEP_M68K - PicoCpu.cycles;
#elif defined(EMU_M68K)
      m68k_set_context(&PicoM68kCPU);
      cyc_done_m68k += m68k_execute(PS_STEP_M68K);
#endif
    } //else dprintf("m68k skipping it #%i", it);
    if (cyc_done_s68k < cyc_do_s68k && it*PS_STEP_S68K > cyc_done_s68k) {
#if defined(EMU_C68K)
      PicoCpuS68k.cycles = PS_STEP_S68K;
      CycloneRun(&PicoCpuS68k);
      cyc_done_s68k += PS_STEP_S68K - PicoCpuS68k.cycles;
#elif defined(EMU_M68K)
      m68k_set_context(&PicoS68kCPU);
      cyc_done_s68k += m68k_execute(PS_STEP_S68K);
#endif
    } //else dprintf("s68k skipping it #%i", it);
  }
  SekCycleCnt += cyc_done_m68k;
  SekCycleCntS68k += cyc_done_s68k;
  //dprintf("== end SekRunPS, it=%i ==", it);
}


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); // "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();
cc68a136	52
	53	return 0;
	54	}
	55
	56	static __inline void SekRun(int cyc)
	57	{
	58	int cyc_do;
	59	SekCycleAim+=cyc;
	60	if((cyc_do=SekCycleAim-SekCycleCnt) < 0) return;
b837b69b	61	#if defined(EMU_C68K)
	62	PicoCpu.cycles=cyc_do;
	63	CycloneRun(&PicoCpu);
	64	SekCycleCnt+=cyc_do-PicoCpu.cycles;
	65	#elif defined(EMU_M68K)
cc68a136	66	m68k_set_context(&PicoM68kCPU);
	67	SekCycleCnt+=m68k_execute(cyc_do);
	68	#endif
	69	}
	70
	71	static __inline void SekRunS68k(int cyc)
	72	{
	73	int cyc_do;
	74	SekCycleAimS68k+=cyc;
	75	if((cyc_do=SekCycleAimS68k-SekCycleCntS68k) < 0) return;
b837b69b	76	#if defined(EMU_C68K)
	77	PicoCpuS68k.cycles=cyc_do;
	78	CycloneRun(&PicoCpuS68k);
	79	SekCycleCntS68k+=cyc_do-PicoCpuS68k.cycles;
	80	#elif defined(EMU_M68K)
cc68a136	81	m68k_set_context(&PicoS68kCPU);
	82	SekCycleCntS68k+=m68k_execute(cyc_do);
	83	#endif
	84	}
	85
68cba51e	86	#define PS_STEP_M68K 8
	87	#define PS_STEP_S68K 13
	88
	89	static __inline void SekRunPS(int cyc_m68k, int cyc_s68k)
	90	{
	91	int cyc_do_m68k, cyc_do_s68k, it=0;
	92	int cyc_done_m68k=0, cyc_done_s68k=0;
	93	SekCycleAim+=cyc_m68k;
	94	SekCycleAimS68k+=cyc_s68k;
	95	cyc_do_m68k=SekCycleAim-SekCycleCnt;
	96	cyc_do_s68k=SekCycleAimS68k-SekCycleCntS68k;
	97	while (cyc_done_m68k < cyc_do_m68k \|\| cyc_done_s68k < cyc_do_s68k) {
	98	it++;
	99	if (cyc_done_m68k < cyc_do_m68k && it*PS_STEP_M68K > cyc_done_m68k) {
	100	#if defined(EMU_C68K)
	101	PicoCpu.cycles = PS_STEP_M68K;
	102	CycloneRun(&PicoCpu);
	103	cyc_done_m68k += PS_STEP_M68K - PicoCpu.cycles;
	104	#elif defined(EMU_M68K)
	105	m68k_set_context(&PicoM68kCPU);
	106	cyc_done_m68k += m68k_execute(PS_STEP_M68K);
	107	#endif
	108	} //else dprintf("m68k skipping it #%i", it);
	109	if (cyc_done_s68k < cyc_do_s68k && it*PS_STEP_S68K > cyc_done_s68k) {
	110	#if defined(EMU_C68K)
	111	PicoCpuS68k.cycles = PS_STEP_S68K;
	112	CycloneRun(&PicoCpuS68k);
	113	cyc_done_s68k += PS_STEP_S68K - PicoCpuS68k.cycles;
	114	#elif defined(EMU_M68K)
	115	m68k_set_context(&PicoS68kCPU);
	116	cyc_done_s68k += m68k_execute(PS_STEP_S68K);
	117	#endif
	118	} //else dprintf("s68k skipping it #%i", it);
	119	}
	120	SekCycleCnt += cyc_done_m68k;
	121	SekCycleCntS68k += cyc_done_s68k;
	122	//dprintf("== end SekRunPS, it=%i ==", it);
	123	}
	124
	125
bf098bc5	126	static __inline void check_cd_dma(void)
	127	{
	128	int ddx;
	129
c459aefd	130	if (!(Pico_mcd->scd.Status_CDC & 0x08)) return;
bf098bc5	131
	132	ddx = Pico_mcd->s68k_regs[4] & 7;
	133	if (ddx < 2) return; // invalid
c459aefd	134	if (ddx < 4) {
	135	Pico_mcd->s68k_regs[4] \|= 0x40; // Data set ready in host port
	136	return;
	137	}
bf098bc5	138	if (ddx == 6) return; // invalid
	139
	140	Update_CDC_TRansfer(ddx); // now go and do the actual transfer
	141	}
	142
4f265db7	143	static __inline void update_chips(void)
	144	{
	145	int counter_timer, int3_set;
	146	int counter75hz_lim = Pico.m.pal ? 2080 : 2096;
	147
	148	// 75Hz CDC update
	149	if ((Pico_mcd->m.counter75hz+=10) >= counter75hz_lim) {
	150	Pico_mcd->m.counter75hz -= counter75hz_lim;
	151	Check_CD_Command();
	152	}
	153
	154	// update timers
	155	counter_timer = Pico.m.pal ? 0x21630 : 0x2121c; // 136752 : 135708;
	156	Pico_mcd->m.timer_stopwatch += counter_timer;
	157	if ((int3_set = Pico_mcd->s68k_regs[0x31])) {
	158	Pico_mcd->m.timer_int3 -= counter_timer;
	159	if (Pico_mcd->m.timer_int3 < 0) {
	160	if (Pico_mcd->s68k_regs[0x33] & (1<<3)) {
	161	dprintf("s68k: timer irq 3");
	162	SekInterruptS68k(3);
	163	Pico_mcd->m.timer_int3 += int3_set << 16;
	164	}
	165	// is this really what happens if irq3 is masked out?
	166	Pico_mcd->m.timer_int3 &= 0xffffff;
	167	}
	168	}
	169
	170	// update gfx chip
	171	if (Pico_mcd->rot_comp.Reg_58 & 0x8000)
	172	gfx_cd_update();
	173	}
	174
b837b69b	175
cc68a136	176	static int PicoFrameHintsMCD(void)
	177	{
	178	struct PicoVideo *pv=&Pico.video;
4f265db7	179	int total_z80=0,lines,y,lines_vis = 224,z80CycleAim = 0,line_sample;
cc68a136	180	const int cycles_68k=488,cycles_z80=228,cycles_s68k=795; // both PAL and NTSC compile to same values
	181	int skip=PicoSkipFrame \|\| (PicoOpt&0x10);
	182	int hint; // Hint counter
	183
	184	if(Pico.m.pal) { //
	185	//cycles_68k = (int) ((double) OSC_PAL / 7 / 50 / 312 + 0.4); // should compile to a constant (488)
	186	//cycles_z80 = (int) ((double) OSC_PAL / 15 / 50 / 312 + 0.4); // 228
	187	lines = 312; // Steve Snake says there are 313 lines, but this seems to also work well
	188	line_sample = 68;
	189	if(pv->reg[1]&8) lines_vis = 240;
	190	} else {
	191	//cycles_68k = (int) ((double) OSC_NTSC / 7 / 60 / 262 + 0.4); // 488
	192	//cycles_z80 = (int) ((double) OSC_NTSC / 15 / 60 / 262 + 0.4); // 228
	193	lines = 262;
	194	line_sample = 93;
	195	}
	196
	197	SekCyclesReset();
	198	SekCyclesResetS68k();
	199	//z80ExtraCycles = 0;
	200
	201	if(PicoOpt&4)
	202	z80CycleAim = 0;
	203	// z80_resetCycles();
	204
	205	pv->status&=~0x88; // clear V-Int, come out of vblank
	206
	207	hint=pv->reg[10]; // Load H-Int counter
	208	//dprintf("-hint: %i", hint);
	209
	210	for (y=0;y<lines;y++)
	211	{
	212	Pico.m.scanline=(short)y;
	213
	214	// pad delay (for 6 button pads)
	215	if(PicoOpt&0x20) {
	216	if(Pico.m.padDelay[0]++ > 25) Pico.m.padTHPhase[0]=0;
	217	if(Pico.m.padDelay[1]++ > 25) Pico.m.padTHPhase[1]=0;
	218	}
	219
bf098bc5	220	check_cd_dma();
bf098bc5	221
cc68a136	222	// H-Interrupts:
	223	if(y <= lines_vis && --hint < 0) // y <= lines_vis: Comix Zone, Golden Axe
	224	{
	225	//dprintf("rhint:old @ %06x", SekPc);
	226	hint=pv->reg[10]; // Reload H-Int counter
	227	pv->pending_ints\|=0x10;
	228	if (pv->reg[0]&0x10) SekInterrupt(4);
	229	//dprintf("rhint: %i @ %06x [%i\|%i]", hint, SekPc, y, SekCycleCnt);
	230	//dprintf("hint_routine: %x", ((unsigned short)(Pico.ram+0x0B84)<<16)\|(unsigned short)(Pico.ram+0x0B86));
	231	}
	232
	233	// V-Interrupt:
	234	if (y == lines_vis)
	235	{
	236	//dprintf("vint: @ %06x [%i\|%i]", SekPc, y, SekCycleCnt);
	237	pv->status\|=0x88; // V-Int happened, go into vblank
	238	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)
	239	/*if(Pico.m.z80Run && (PicoOpt&4)) {
	240	z80CycleAim+=cycles_z80/2;
	241	total_z80+=z80_run(z80CycleAim-total_z80);
	242	z80CycleAim-=cycles_z80/2;
	243	}*/
	244	pv->pending_ints\|=0x20;
	245	if(pv->reg[1]&0x20) SekInterrupt(6);
	246	if(Pico.m.z80Run && (PicoOpt&4)) // ?
	247	z80_int();
	248	//dprintf("zint: [%i\|%i] zPC=%04x", Pico.m.scanline, SekCyclesDone(), mz80GetRegisterValue(NULL, 0));
	249	}
	250
	251	// decide if we draw this line
	252	#if CAN_HANDLE_240_LINES
	253	if(!skip && ((!(pv->reg[1]&8) && y<224) \|\| ((pv->reg[1]&8) && y<240)) )
	254	#else
	255	if(!skip && y<224)
	256	#endif
	257	PicoLine(y);
	258
	259	if(PicoOpt&1)
	260	sound_timers_and_dac(y);
	261
	262	// get samples from sound chips
7a93adeb	263	if (y == 224 && PsndOut) {
	264	int len = sound_render(0, PsndLen);
	265	if (PicoWriteSound) PicoWriteSound(len);
	266	// clear sound buffer
	267	sound_clear();
	268	}
cc68a136	269
	270	// Run scanline:
	271	//dprintf("m68k starting exec @ %06x", SekPc);
672ad671	272	if(Pico.m.dma_bytes) SekCycleCnt+=CheckDMA();
68cba51e	273	if((PicoOpt & 0x2000) && (Pico_mcd->m.busreq&3) == 1) {
	274	SekRunPS(cycles_68k, cycles_s68k); // "perfect sync"
	275	} else {
	276	SekRun(cycles_68k);
	277	if ((Pico_mcd->m.busreq&3) == 1) // no busreq/no reset
	278	SekRunS68k(cycles_s68k);
cc68a136	279	}
	280
	281	if((PicoOpt&4) && Pico.m.z80Run) {
	282	Pico.m.z80Run\|=2;
	283	z80CycleAim+=cycles_z80;
	284	total_z80+=z80_run(z80CycleAim-total_z80);
	285	}
	286
4f265db7	287	update_chips();
cc68a136	288	}
	289
	290	// draw a frame just after vblank in alternative render mode
	291	if(!PicoSkipFrame && (PicoOpt&0x10))
	292	PicoFrameFull();
	293
	294	return 0;
	295	}
	296
	297
	298	int PicoFrameMCD(void)
	299	{
	300	if(!(PicoOpt&0x10))
	301	PicoFrameStart();
	302
	303	PicoFrameHintsMCD();
	304
	305	return 0;
	306	}
	307
	308