[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
 * - RAM support in mapper
 * - region support
 * - 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 ((d & 0x90) == 0x90 && PsndPsgLine < Pico.m.scanline)
        PsndDoPSG(Pico.m.scanline);
      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();
      }
    }

    // 224 because of how it's done for MD...
    if (y == 224 && PsndOut)
      PsndGetSamplesMS();

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

  if (PsndOut && PsndPsgLine < lines)
    PsndDoPSG(lines - 1);
}

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

  PicoFrameStartMode4();

  for (y = 0; y < lines_vis; y++)
    PicoLineMode4(y);
}

// vim:ts=2:sw=2:expandtab
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	* - RAM support in mapper
	12	* - region support
	13	* - H counter
	14	*/
	15	#include "pico_int.h"
	16	#include "memory.h"
	17	#include "sound/sn76496.h"
	18
	19	static unsigned char vdp_data_read(void)
	20	{
	21	struct PicoVideo *pv = &Pico.video;
	22	unsigned char d;
	23
	24	d = PicoMem.vramb[pv->addr];
	25	pv->addr = (pv->addr + 1) & 0x3fff;
	26	pv->pending = 0;
	27	return d;
	28	}
	29
	30	static unsigned char vdp_ctl_read(void)
	31	{
	32	struct PicoVideo *pv = &Pico.video;
	33	unsigned char d;
	34
	35	d = pv->status \| (pv->pending_ints << 7);
	36	pv->pending = pv->pending_ints = 0;
	37	pv->status = 0;
	38
	39	elprintf(EL_SR, "VDP sr: %02x", d);
	40	return d;
	41	}
	42
	43	static void vdp_data_write(unsigned char d)
	44	{
	45	struct PicoVideo *pv = &Pico.video;
	46
	47	if (pv->type == 3) {
	48	PicoMem.cram[pv->addr & 0x1f] = d;
	49	Pico.m.dirtyPal = 1;
	50	} else {
	51	PicoMem.vramb[pv->addr] = d;
	52	}
	53	pv->addr = (pv->addr + 1) & 0x3fff;
	54
	55	pv->pending = 0;
	56	}
	57
	58	static void vdp_ctl_write(unsigned char d)
	59	{
	60	struct PicoVideo *pv = &Pico.video;
	61
	62	if (pv->pending) {
	63	if ((d >> 6) == 2) {
	64	pv->reg[d & 0x0f] = pv->addr;
	65	elprintf(EL_IO, " VDP r%02x=%02x", d & 0x0f, pv->addr & 0xff);
	66	}
	67	pv->type = d >> 6;
	68	pv->addr &= 0x00ff;
	69	pv->addr \|= (d & 0x3f) << 8;
	70	} else {
	71	pv->addr &= 0x3f00;
	72	pv->addr \|= d;
	73	}
	74	pv->pending ^= 1;
	75	}
	76
	77	static unsigned char z80_sms_in(unsigned short a)
	78	{
	79	unsigned char d = 0;
	80
	81	elprintf(EL_IO, "z80 port %04x read", a);
	82	a &= 0xc1;
	83	switch (a)
	84	{
	85	case 0x00:
	86	case 0x01:
	87	d = 0xff;
	88	break;
	89
	90	case 0x40: /* V counter */
	91	d = Pico.video.v_counter;
	92	elprintf(EL_HVCNT, "V counter read: %02x", d);
	93	break;
	94
	95	case 0x41: /* H counter */
	96	d = Pico.m.rotate++;
	97	elprintf(EL_HVCNT, "H counter read: %02x", d);
	98	break;
	99
	100	case 0x80:
	101	d = vdp_data_read();
	102	break;
	103
	104	case 0x81:
	105	d = vdp_ctl_read();
	106	break;
	107
	108	case 0xc0: /* I/O port A and B */
	109	d = ~((PicoIn.pad[0] & 0x3f) \| (PicoIn.pad[1] << 6));
	110	break;
	111
	112	case 0xc1: /* I/O port B and miscellaneous */
	113	d = (Pico.ms.io_ctl & 0x80) \| ((Pico.ms.io_ctl << 1) & 0x40) \| 0x30;
	114	d \|= ~(PicoIn.pad[1] >> 2) & 0x0f;
	115	break;
	116	}
	117
	118	elprintf(EL_IO, "ret = %02x", d);
	119	return d;
	120	}
	121
	122	static void z80_sms_out(unsigned short a, unsigned char d)
	123	{
	124	elprintf(EL_IO, "z80 port %04x write %02x", a, d);
	125	a &= 0xc1;
	126	switch (a)
	127	{
	128	case 0x01:
	129	Pico.ms.io_ctl = d;
	130	break;
	131
	132	case 0x40:
	133	case 0x41:
	134	if ((d & 0x90) == 0x90 && PsndPsgLine < Pico.m.scanline)
	135	PsndDoPSG(Pico.m.scanline);
	136	SN76496Write(d);
	137	break;
	138
	139	case 0x80:
	140	vdp_data_write(d);
	141	break;
	142
	143	case 0x81:
	144	vdp_ctl_write(d);
	145	break;
	146	}
	147	}
	148
	149	static int bank_mask;
	150
	151	static void write_bank(unsigned short a, unsigned char d)
	152	{
	153	elprintf(EL_Z80BNK, "bank %04x %02x @ %04x", a, d, z80_pc());
	154	switch (a & 0x0f)
	155	{
	156	case 0x0c:
	157	elprintf(EL_STATUS\|EL_ANOMALY, "%02x written to control reg!", d);
	158	break;
	159	case 0x0d:
	160	if (d != 0)
	161	elprintf(EL_STATUS\|EL_ANOMALY, "bank0 changed to %d!", d);
	162	break;
	163	case 0x0e:
	164	d &= bank_mask;
	165	z80_map_set(z80_read_map, 0x4000, 0x7fff, Pico.rom + (d << 14), 0);
	166	#ifdef _USE_CZ80
	167	Cz80_Set_Fetch(&CZ80, 0x4000, 0x7fff, (FPTR)Pico.rom + (d << 14));
	168	#endif
	169	break;
	170	case 0x0f:
	171	d &= bank_mask;
	172	z80_map_set(z80_read_map, 0x8000, 0xbfff, Pico.rom + (d << 14), 0);
	173	#ifdef _USE_CZ80
	174	Cz80_Set_Fetch(&CZ80, 0x8000, 0xbfff, (FPTR)Pico.rom + (d << 14));
	175	#endif
	176	break;
	177	}
	178	Pico.ms.carthw[a & 0x0f] = d;
	179	}
	180
	181	static void xwrite(unsigned int a, unsigned char d)
	182	{
	183	elprintf(EL_IO, "z80 write [%04x] %02x", a, d);
	184	if (a >= 0xc000)
	185	PicoMem.zram[a & 0x1fff] = d;
	186	if (a >= 0xfff8)
	187	write_bank(a, d);
	188	}
	189
	190	void PicoResetMS(void)
	191	{
	192	z80_reset();
	193	PsndReset(); // pal must be known here
	194	}
	195
	196	void PicoPowerMS(void)
	197	{
	198	int s, tmp;
	199
	200	memset(&PicoMem,0,sizeof(PicoMem));
	201	memset(&Pico.video,0,sizeof(Pico.video));
	202	memset(&Pico.m,0,sizeof(Pico.m));
	203	Pico.m.pal = 0;
	204
	205	// calculate a mask for bank writes.
	206	// ROM loader has aligned the size for us, so this is safe.
	207	s = 0; tmp = Pico.romsize;
	208	while ((tmp >>= 1) != 0)
	209	s++;
	210	if (Pico.romsize > (1 << s))
	211	s++;
	212	tmp = 1 << s;
	213	bank_mask = (tmp - 1) >> 14;
	214
	215	Pico.ms.carthw[0x0e] = 1;
	216	Pico.ms.carthw[0x0f] = 2;
	217
	218	PicoReset();
	219	}
	220
	221	void PicoMemSetupMS(void)
	222	{
	223	z80_map_set(z80_read_map, 0x0000, 0xbfff, Pico.rom, 0);
	224	z80_map_set(z80_read_map, 0xc000, 0xdfff, PicoMem.zram, 0);
	225	z80_map_set(z80_read_map, 0xe000, 0xffff, PicoMem.zram, 0);
	226
	227	z80_map_set(z80_write_map, 0x0000, 0xbfff, xwrite, 1);
	228	z80_map_set(z80_write_map, 0xc000, 0xdfff, PicoMem.zram, 0);
	229	z80_map_set(z80_write_map, 0xe000, 0xffff, xwrite, 1);
	230
	231	#ifdef _USE_DRZ80
	232	drZ80.z80_in = z80_sms_in;
	233	drZ80.z80_out = z80_sms_out;
	234	#endif
	235	#ifdef _USE_CZ80
	236	Cz80_Set_Fetch(&CZ80, 0x0000, 0xbfff, (FPTR)Pico.rom);
	237	Cz80_Set_Fetch(&CZ80, 0xc000, 0xdfff, (FPTR)PicoMem.zram);
	238	Cz80_Set_Fetch(&CZ80, 0xe000, 0xffff, (FPTR)PicoMem.zram);
	239	Cz80_Set_INPort(&CZ80, z80_sms_in);
	240	Cz80_Set_OUTPort(&CZ80, z80_sms_out);
	241	#endif
	242	}
	243
	244	void PicoStateLoadedMS(void)
	245	{
	246	write_bank(0xfffe, Pico.ms.carthw[0x0e]);
	247	write_bank(0xffff, Pico.ms.carthw[0x0f]);
	248	}
	249
	250	void PicoFrameMS(void)
	251	{
	252	struct PicoVideo *pv = &Pico.video;
	253	int is_pal = Pico.m.pal;
	254	int lines = is_pal ? 313 : 262;
	255	int cycles_line = is_pal ? 58020 : 58293; /* (226.6 : 227.7) * 256 */
	256	int cycles_done = 0, cycles_aim = 0;
	257	int skip = PicoIn.skipFrame;
	258	int lines_vis = 192;
	259	int hint; // Hint counter
	260	int nmi;
	261	int y;
	262
	263	PsndStartFrame();
	264
	265	nmi = (PicoIn.pad[0] >> 7) & 1;
	266	if (!Pico.ms.nmi_state && nmi)
	267	z80_nmi();
	268	Pico.ms.nmi_state = nmi;
	269
	270	PicoFrameStartMode4();
	271	hint = pv->reg[0x0a];
	272
	273	for (y = 0; y < lines; y++)
	274	{
	275	pv->v_counter = Pico.m.scanline = y;
	276	if (y > 218)
	277	pv->v_counter = y - 6;
	278
	279	if (y < lines_vis && !skip)
	280	PicoLineMode4(y);
	281
	282	if (y <= lines_vis)
	283	{
	284	if (--hint < 0)
	285	{
	286	hint = pv->reg[0x0a];
	287	pv->pending_ints \|= 2;
	288	if (pv->reg[0] & 0x10) {
	289	elprintf(EL_INTS, "hint");
	290	z80_int();
	291	}
	292	}
	293	}
	294	else if (y == lines_vis + 1) {
	295	pv->pending_ints \|= 1;
	296	if (pv->reg[1] & 0x20) {
	297	elprintf(EL_INTS, "vint");
	298	z80_int();
	299	}
	300	}
	301
	302	// 224 because of how it's done for MD...
	303	if (y == 224 && PsndOut)
	304	PsndGetSamplesMS();
	305
	306	cycles_aim += cycles_line;
	307	cycles_done += z80_run((cycles_aim - cycles_done) >> 8) << 8;
	308	}
	309
	310	if (PsndOut && PsndPsgLine < lines)
	311	PsndDoPSG(lines - 1);
	312	}
	313
	314	void PicoFrameDrawOnlyMS(void)
	315	{
	316	int lines_vis = 192;
	317	int y;
	318
	319	PicoFrameStartMode4();
	320
	321	for (y = 0; y < lines_vis; y++)
	322	PicoLineMode4(y);
	323	}
	324
	325	// vim:ts=2:sw=2:expandtab