[picodrive.git] / pico / sms.c

/*
 * SMS emulation
 * (C) notaz, 2009-2010
 *
 * This work is licensed under the terms of MAME license.
 * See COPYING file in the top-level directory.
 */
/*
 * TODO:
 * - start in a state as if BIOS ran
 * - remaining status flags (OVR/COL)
 * - RAM support in mapper
 * - region support
 * - SN76496 DAC-like usage
 * - H counter
 */
#include "pico_int.h"
#include "memory.h"
#include "sound/sn76496.h"

static unsigned char vdp_data_read(void)
{
  struct PicoVideo *pv = &Pico.video;
  unsigned char d;

  d = PicoMem.vramb[pv->addr];
  pv->addr = (pv->addr + 1) & 0x3fff;
  pv->pending = 0;
  return d;
}

static unsigned char vdp_ctl_read(void)
{
  struct PicoVideo *pv = &Pico.video;
  unsigned char d;

  d = pv->status | (pv->pending_ints << 7);
  pv->pending = pv->pending_ints = 0;
  pv->status = 0;

  elprintf(EL_SR, "VDP sr: %02x", d);
  return d;
}

static void vdp_data_write(unsigned char d)
{
  struct PicoVideo *pv = &Pico.video;

  if (pv->type == 3) {
    PicoMem.cram[pv->addr & 0x1f] = d;
    Pico.m.dirtyPal = 1;
  } else {
    PicoMem.vramb[pv->addr] = d;
  }
  pv->addr = (pv->addr + 1) & 0x3fff;

  pv->pending = 0;
}

static void vdp_ctl_write(unsigned char d)
{
  struct PicoVideo *pv = &Pico.video;

  if (pv->pending) {
    if ((d >> 6) == 2) {
      pv->reg[d & 0x0f] = pv->addr;
      elprintf(EL_IO, "  VDP r%02x=%02x", d & 0x0f, pv->addr & 0xff);
    }
    pv->type = d >> 6;
    pv->addr &= 0x00ff;
    pv->addr |= (d & 0x3f) << 8;
  } else {
    pv->addr &= 0x3f00;
    pv->addr |= d;
  }
  pv->pending ^= 1;
}

static unsigned char z80_sms_in(unsigned short a)
{
  unsigned char d = 0;

  elprintf(EL_IO, "z80 port %04x read", a);
  a &= 0xc1;
  switch (a)
  {
    case 0x00:
    case 0x01:
      d = 0xff;
      break;

    case 0x40: /* V counter */
      d = Pico.video.v_counter;
      elprintf(EL_HVCNT, "V counter read: %02x", d);
      break;

    case 0x41: /* H counter */
      d = Pico.m.rotate++;
      elprintf(EL_HVCNT, "H counter read: %02x", d);
      break;

    case 0x80:
      d = vdp_data_read();
      break;

    case 0x81:
      d = vdp_ctl_read();
      break;

    case 0xc0: /* I/O port A and B */
      d = ~((PicoIn.pad[0] & 0x3f) | (PicoIn.pad[1] << 6));
      break;

    case 0xc1: /* I/O port B and miscellaneous */
      d = (Pico.ms.io_ctl & 0x80) | ((Pico.ms.io_ctl << 1) & 0x40) | 0x30;
      d |= ~(PicoIn.pad[1] >> 2) & 0x0f;
      break;
  }

  elprintf(EL_IO, "ret = %02x", d);
  return d;
}

static void z80_sms_out(unsigned short a, unsigned char d)
{
  elprintf(EL_IO, "z80 port %04x write %02x", a, d);
  a &= 0xc1;
  switch (a)
  {
    case 0x01:
      Pico.ms.io_ctl = d;
      break;

    case 0x40:
    case 0x41:
      if (PicoIn.opt & POPT_EN_PSG)
        SN76496Write(d);
      break;

    case 0x80:
      vdp_data_write(d);
      break;

    case 0x81:
      vdp_ctl_write(d);
      break;
  }
}

static int bank_mask;

static void write_bank(unsigned short a, unsigned char d)
{
  elprintf(EL_Z80BNK, "bank %04x %02x @ %04x", a, d, z80_pc());
  switch (a & 0x0f)
  {
    case 0x0c:
      elprintf(EL_STATUS|EL_ANOMALY, "%02x written to control reg!", d);
      break;
    case 0x0d:
      if (d != 0)
        elprintf(EL_STATUS|EL_ANOMALY, "bank0 changed to %d!", d);
      break;
    case 0x0e:
      d &= bank_mask;
      z80_map_set(z80_read_map, 0x4000, 0x7fff, Pico.rom + (d << 14), 0);
#ifdef _USE_CZ80
      Cz80_Set_Fetch(&CZ80, 0x4000, 0x7fff, (FPTR)Pico.rom + (d << 14));
#endif
      break;
    case 0x0f:
      d &= bank_mask;
      z80_map_set(z80_read_map, 0x8000, 0xbfff, Pico.rom + (d << 14), 0);
#ifdef _USE_CZ80
      Cz80_Set_Fetch(&CZ80, 0x8000, 0xbfff, (FPTR)Pico.rom + (d << 14));
#endif
      break;
  }
  Pico.ms.carthw[a & 0x0f] = d;
}

static void xwrite(unsigned int a, unsigned char d)
{
  elprintf(EL_IO, "z80 write [%04x] %02x", a, d);
  if (a >= 0xc000)
    PicoMem.zram[a & 0x1fff] = d;
  if (a >= 0xfff8)
    write_bank(a, d);
}

void PicoResetMS(void)
{
  z80_reset();
  PsndReset(); // pal must be known here
}

void PicoPowerMS(void)
{
  int s, tmp;

  memset(&PicoMem,0,sizeof(PicoMem));
  memset(&Pico.video,0,sizeof(Pico.video));
  memset(&Pico.m,0,sizeof(Pico.m));
  Pico.m.pal = 0;

  // calculate a mask for bank writes.
  // ROM loader has aligned the size for us, so this is safe.
  s = 0; tmp = Pico.romsize;
  while ((tmp >>= 1) != 0)
    s++;
  if (Pico.romsize > (1 << s))
    s++;
  tmp = 1 << s;
  bank_mask = (tmp - 1) >> 14;

  Pico.ms.carthw[0x0e] = 1;
  Pico.ms.carthw[0x0f] = 2;

  PicoReset();
}

void PicoMemSetupMS(void)
{
  z80_map_set(z80_read_map, 0x0000, 0xbfff, Pico.rom, 0);
  z80_map_set(z80_read_map, 0xc000, 0xdfff, PicoMem.zram, 0);
  z80_map_set(z80_read_map, 0xe000, 0xffff, PicoMem.zram, 0);

  z80_map_set(z80_write_map, 0x0000, 0xbfff, xwrite, 1);
  z80_map_set(z80_write_map, 0xc000, 0xdfff, PicoMem.zram, 0);
  z80_map_set(z80_write_map, 0xe000, 0xffff, xwrite, 1);
 
#ifdef _USE_DRZ80
  drZ80.z80_in = z80_sms_in;
  drZ80.z80_out = z80_sms_out;
#endif
#ifdef _USE_CZ80
  Cz80_Set_Fetch(&CZ80, 0x0000, 0xbfff, (FPTR)Pico.rom);
  Cz80_Set_Fetch(&CZ80, 0xc000, 0xdfff, (FPTR)PicoMem.zram);
  Cz80_Set_Fetch(&CZ80, 0xe000, 0xffff, (FPTR)PicoMem.zram);
  Cz80_Set_INPort(&CZ80, z80_sms_in);
  Cz80_Set_OUTPort(&CZ80, z80_sms_out);
#endif
}

void PicoStateLoadedMS(void)
{
  write_bank(0xfffe, Pico.ms.carthw[0x0e]);
  write_bank(0xffff, Pico.ms.carthw[0x0f]);
}

void PicoFrameMS(void)
{
  struct PicoVideo *pv = &Pico.video;
  int is_pal = Pico.m.pal;
  int lines = is_pal ? 313 : 262;
  int cycles_line = is_pal ? 58020 : 58293; /* (226.6 : 227.7) * 256 */
  int cycles_done = 0, cycles_aim = 0;
  int skip = PicoIn.skipFrame;
  int lines_vis = 192;
  int hint; // Hint counter
  int nmi;
  int y;

  PsndStartFrame();

  nmi = (PicoIn.pad[0] >> 7) & 1;
  if (!Pico.ms.nmi_state && nmi)
    z80_nmi();
  Pico.ms.nmi_state = nmi;

  PicoFrameStartMode4();
  hint = pv->reg[0x0a];

  for (y = 0; y < lines; y++)
  {
    pv->v_counter = Pico.m.scanline = y;
    if (y > 218)
      pv->v_counter = y - 6;

    if (y < lines_vis && !skip)
      PicoLineMode4(y);

    if (y <= lines_vis)
    {
      if (--hint < 0)
      {
        hint = pv->reg[0x0a];
        pv->pending_ints |= 2;
        if (pv->reg[0] & 0x10) {
          elprintf(EL_INTS, "hint");
          z80_int();
        }
      }
    }
    else if (y == lines_vis + 1) {
      pv->pending_ints |= 1;
      if (pv->reg[1] & 0x20) {
        elprintf(EL_INTS, "vint");
        z80_int();
      }
    }

    cycles_aim += cycles_line;
    cycles_done += z80_run((cycles_aim - cycles_done) >> 8) << 8;
  }

  if (PsndOut)
    PsndGetSamplesMS();
}

void PicoFrameDrawOnlyMS(void)
{
  int lines_vis = 192;
  int y;

  PicoFrameStartMode4();

  for (y = 0; y < lines_vis; y++)
    PicoLineMode4(y);
}
Commit	Line	Data
	1	/*
	2	* SMS emulation
	3	* (C) notaz, 2009-2010
	4	*
	5	* This work is licensed under the terms of MAME license.
	6	* See COPYING file in the top-level directory.
	7	*/
	8	/*
	9	* TODO:
	10	* - start in a state as if BIOS ran
	11	* - remaining status flags (OVR/COL)
	12	* - RAM support in mapper
	13	* - region support
	14	* - SN76496 DAC-like usage
	15	* - H counter
	16	*/
	17	#include "pico_int.h"
	18	#include "memory.h"
	19	#include "sound/sn76496.h"
	20
	21	static unsigned char vdp_data_read(void)
	22	{
	23	struct PicoVideo *pv = &Pico.video;
	24	unsigned char d;
	25
	26	d = PicoMem.vramb[pv->addr];
	27	pv->addr = (pv->addr + 1) & 0x3fff;
	28	pv->pending = 0;
	29	return d;
	30	}
	31
	32	static unsigned char vdp_ctl_read(void)
	33	{
	34	struct PicoVideo *pv = &Pico.video;
	35	unsigned char d;
	36
	37	d = pv->status \| (pv->pending_ints << 7);
	38	pv->pending = pv->pending_ints = 0;
	39	pv->status = 0;
	40
	41	elprintf(EL_SR, "VDP sr: %02x", d);
	42	return d;
	43	}
	44
	45	static void vdp_data_write(unsigned char d)
	46	{
	47	struct PicoVideo *pv = &Pico.video;
	48
	49	if (pv->type == 3) {
	50	PicoMem.cram[pv->addr & 0x1f] = d;
	51	Pico.m.dirtyPal = 1;
	52	} else {
	53	PicoMem.vramb[pv->addr] = d;
	54	}
	55	pv->addr = (pv->addr + 1) & 0x3fff;
	56
	57	pv->pending = 0;
	58	}
	59
	60	static void vdp_ctl_write(unsigned char d)
	61	{
	62	struct PicoVideo *pv = &Pico.video;
	63
	64	if (pv->pending) {
	65	if ((d >> 6) == 2) {
	66	pv->reg[d & 0x0f] = pv->addr;
	67	elprintf(EL_IO, " VDP r%02x=%02x", d & 0x0f, pv->addr & 0xff);
	68	}
	69	pv->type = d >> 6;
	70	pv->addr &= 0x00ff;
	71	pv->addr \|= (d & 0x3f) << 8;
	72	} else {
	73	pv->addr &= 0x3f00;
	74	pv->addr \|= d;
	75	}
	76	pv->pending ^= 1;
	77	}
	78
	79	static unsigned char z80_sms_in(unsigned short a)
	80	{
	81	unsigned char d = 0;
	82
	83	elprintf(EL_IO, "z80 port %04x read", a);
	84	a &= 0xc1;
	85	switch (a)
	86	{
	87	case 0x00:
	88	case 0x01:
	89	d = 0xff;
	90	break;
	91
	92	case 0x40: /* V counter */
	93	d = Pico.video.v_counter;
	94	elprintf(EL_HVCNT, "V counter read: %02x", d);
	95	break;
	96
	97	case 0x41: /* H counter */
	98	d = Pico.m.rotate++;
	99	elprintf(EL_HVCNT, "H counter read: %02x", d);
	100	break;
	101
	102	case 0x80:
	103	d = vdp_data_read();
	104	break;
	105
	106	case 0x81:
	107	d = vdp_ctl_read();
	108	break;
	109
	110	case 0xc0: /* I/O port A and B */
	111	d = ~((PicoIn.pad[0] & 0x3f) \| (PicoIn.pad[1] << 6));
	112	break;
	113
	114	case 0xc1: /* I/O port B and miscellaneous */
	115	d = (Pico.ms.io_ctl & 0x80) \| ((Pico.ms.io_ctl << 1) & 0x40) \| 0x30;
	116	d \|= ~(PicoIn.pad[1] >> 2) & 0x0f;
	117	break;
	118	}
	119
	120	elprintf(EL_IO, "ret = %02x", d);
	121	return d;
	122	}
	123
	124	static void z80_sms_out(unsigned short a, unsigned char d)
	125	{
	126	elprintf(EL_IO, "z80 port %04x write %02x", a, d);
	127	a &= 0xc1;
	128	switch (a)
	129	{
	130	case 0x01:
	131	Pico.ms.io_ctl = d;
	132	break;
	133
	134	case 0x40:
	135	case 0x41:
	136	if (PicoIn.opt & POPT_EN_PSG)
	137	SN76496Write(d);
	138	break;
	139
	140	case 0x80:
	141	vdp_data_write(d);
	142	break;
	143
	144	case 0x81:
	145	vdp_ctl_write(d);
	146	break;
	147	}
	148	}
	149
	150	static int bank_mask;
	151
	152	static void write_bank(unsigned short a, unsigned char d)
	153	{
	154	elprintf(EL_Z80BNK, "bank %04x %02x @ %04x", a, d, z80_pc());
	155	switch (a & 0x0f)
	156	{
	157	case 0x0c:
	158	elprintf(EL_STATUS\|EL_ANOMALY, "%02x written to control reg!", d);
	159	break;
	160	case 0x0d:
	161	if (d != 0)
	162	elprintf(EL_STATUS\|EL_ANOMALY, "bank0 changed to %d!", d);
	163	break;
	164	case 0x0e:
	165	d &= bank_mask;
	166	z80_map_set(z80_read_map, 0x4000, 0x7fff, Pico.rom + (d << 14), 0);
	167	#ifdef _USE_CZ80
	168	Cz80_Set_Fetch(&CZ80, 0x4000, 0x7fff, (FPTR)Pico.rom + (d << 14));
	169	#endif
	170	break;
	171	case 0x0f:
	172	d &= bank_mask;
	173	z80_map_set(z80_read_map, 0x8000, 0xbfff, Pico.rom + (d << 14), 0);
	174	#ifdef _USE_CZ80
	175	Cz80_Set_Fetch(&CZ80, 0x8000, 0xbfff, (FPTR)Pico.rom + (d << 14));
	176	#endif
	177	break;
	178	}
	179	Pico.ms.carthw[a & 0x0f] = d;
	180	}
	181
	182	static void xwrite(unsigned int a, unsigned char d)
	183	{
	184	elprintf(EL_IO, "z80 write [%04x] %02x", a, d);
	185	if (a >= 0xc000)
	186	PicoMem.zram[a & 0x1fff] = d;
	187	if (a >= 0xfff8)
	188	write_bank(a, d);
	189	}
	190
	191	void PicoResetMS(void)
	192	{
	193	z80_reset();
	194	PsndReset(); // pal must be known here
	195	}
	196
	197	void PicoPowerMS(void)
	198	{
	199	int s, tmp;
	200
	201	memset(&PicoMem,0,sizeof(PicoMem));
	202	memset(&Pico.video,0,sizeof(Pico.video));
	203	memset(&Pico.m,0,sizeof(Pico.m));
	204	Pico.m.pal = 0;
	205
	206	// calculate a mask for bank writes.
	207	// ROM loader has aligned the size for us, so this is safe.
	208	s = 0; tmp = Pico.romsize;
	209	while ((tmp >>= 1) != 0)
	210	s++;
	211	if (Pico.romsize > (1 << s))
	212	s++;
	213	tmp = 1 << s;
	214	bank_mask = (tmp - 1) >> 14;
	215
	216	Pico.ms.carthw[0x0e] = 1;
	217	Pico.ms.carthw[0x0f] = 2;
	218
	219	PicoReset();
	220	}
	221
	222	void PicoMemSetupMS(void)
	223	{
	224	z80_map_set(z80_read_map, 0x0000, 0xbfff, Pico.rom, 0);
	225	z80_map_set(z80_read_map, 0xc000, 0xdfff, PicoMem.zram, 0);
	226	z80_map_set(z80_read_map, 0xe000, 0xffff, PicoMem.zram, 0);
	227
	228	z80_map_set(z80_write_map, 0x0000, 0xbfff, xwrite, 1);
	229	z80_map_set(z80_write_map, 0xc000, 0xdfff, PicoMem.zram, 0);
	230	z80_map_set(z80_write_map, 0xe000, 0xffff, xwrite, 1);
	231
	232	#ifdef _USE_DRZ80
	233	drZ80.z80_in = z80_sms_in;
	234	drZ80.z80_out = z80_sms_out;
	235	#endif
	236	#ifdef _USE_CZ80
	237	Cz80_Set_Fetch(&CZ80, 0x0000, 0xbfff, (FPTR)Pico.rom);
	238	Cz80_Set_Fetch(&CZ80, 0xc000, 0xdfff, (FPTR)PicoMem.zram);
	239	Cz80_Set_Fetch(&CZ80, 0xe000, 0xffff, (FPTR)PicoMem.zram);
	240	Cz80_Set_INPort(&CZ80, z80_sms_in);
	241	Cz80_Set_OUTPort(&CZ80, z80_sms_out);
	242	#endif
	243	}
	244
	245	void PicoStateLoadedMS(void)
	246	{
	247	write_bank(0xfffe, Pico.ms.carthw[0x0e]);
	248	write_bank(0xffff, Pico.ms.carthw[0x0f]);
	249	}
	250
	251	void PicoFrameMS(void)
	252	{
	253	struct PicoVideo *pv = &Pico.video;
	254	int is_pal = Pico.m.pal;
	255	int lines = is_pal ? 313 : 262;
	256	int cycles_line = is_pal ? 58020 : 58293; /* (226.6 : 227.7) * 256 */
	257	int cycles_done = 0, cycles_aim = 0;
	258	int skip = PicoIn.skipFrame;
	259	int lines_vis = 192;
	260	int hint; // Hint counter
	261	int nmi;
	262	int y;
	263
	264	PsndStartFrame();
	265
	266	nmi = (PicoIn.pad[0] >> 7) & 1;
	267	if (!Pico.ms.nmi_state && nmi)
	268	z80_nmi();
	269	Pico.ms.nmi_state = nmi;
	270
	271	PicoFrameStartMode4();
	272	hint = pv->reg[0x0a];
	273
	274	for (y = 0; y < lines; y++)
	275	{
	276	pv->v_counter = Pico.m.scanline = y;
	277	if (y > 218)
	278	pv->v_counter = y - 6;
	279
	280	if (y < lines_vis && !skip)
	281	PicoLineMode4(y);
	282
	283	if (y <= lines_vis)
	284	{
	285	if (--hint < 0)
	286	{
	287	hint = pv->reg[0x0a];
	288	pv->pending_ints \|= 2;
	289	if (pv->reg[0] & 0x10) {
	290	elprintf(EL_INTS, "hint");
	291	z80_int();
	292	}
	293	}
	294	}
	295	else if (y == lines_vis + 1) {
	296	pv->pending_ints \|= 1;
	297	if (pv->reg[1] & 0x20) {
	298	elprintf(EL_INTS, "vint");
	299	z80_int();
	300	}
	301	}
	302
	303	cycles_aim += cycles_line;
	304	cycles_done += z80_run((cycles_aim - cycles_done) >> 8) << 8;
	305	}
	306
	307	if (PsndOut)
	308	PsndGetSamplesMS();
	309	}
	310
	311	void PicoFrameDrawOnlyMS(void)
	312	{
	313	int lines_vis = 192;
	314	int y;
	315
	316	PicoFrameStartMode4();
	317
	318	for (y = 0; y < lines_vis; y++)
	319	PicoLineMode4(y);
	320	}
	321