[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;

  z80_int_assert(0);
  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 NOINLINE void vdp_reg_write(struct PicoVideo *pv, u8 a, u8 d)
{
  int l;

  pv->reg[a] = d;
  switch (a) {
  case 0:
    l = pv->pending_ints & (d >> 3) & 2;
    elprintf(EL_INTS, "hint %d", l);
    z80_int_assert(l);
    break;
  case 1:
    l = pv->pending_ints & (d >> 5) & 1;
    elprintf(EL_INTS, "vint %d", l);
    z80_int_assert(l);
    break;
  }
}

static void vdp_ctl_write(u8 d)
{
  struct PicoVideo *pv = &Pico.video;

  if (pv->pending) {
    if ((d >> 6) == 2) {
      elprintf(EL_IO, "  VDP r%02x=%02x", d & 0x0f, pv->addr & 0xff);
      if (pv->reg[d & 0x0f] != (u8)pv->addr)
        vdp_reg_write(pv, d & 0x0f, pv->addr);
    }
    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 && Pico.snd.psg_line < 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_assert(1);
        }
      }
    }
    else if (y == lines_vis + 1) {
      pv->pending_ints |= 1;
      if (pv->reg[1] & 0x20) {
        elprintf(EL_INTS, "vint");
        z80_int_assert(1);
      }
    }

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

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

  if (PicoIn.sndOut && Pico.snd.psg_line < 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	z80_int_assert(0);
	36	d = pv->status \| (pv->pending_ints << 7);
	37	pv->pending = pv->pending_ints = 0;
	38	pv->status = 0;
	39
	40	elprintf(EL_SR, "VDP sr: %02x", d);
	41	return d;
	42	}
	43
	44	static void vdp_data_write(unsigned char d)
	45	{
	46	struct PicoVideo *pv = &Pico.video;
	47
	48	if (pv->type == 3) {
	49	PicoMem.cram[pv->addr & 0x1f] = d;
	50	Pico.m.dirtyPal = 1;
	51	} else {
	52	PicoMem.vramb[pv->addr] = d;
	53	}
	54	pv->addr = (pv->addr + 1) & 0x3fff;
	55
	56	pv->pending = 0;
	57	}
	58
	59	static NOINLINE void vdp_reg_write(struct PicoVideo *pv, u8 a, u8 d)
	60	{
	61	int l;
	62
	63	pv->reg[a] = d;
	64	switch (a) {
	65	case 0:
	66	l = pv->pending_ints & (d >> 3) & 2;
	67	elprintf(EL_INTS, "hint %d", l);
	68	z80_int_assert(l);
	69	break;
	70	case 1:
	71	l = pv->pending_ints & (d >> 5) & 1;
	72	elprintf(EL_INTS, "vint %d", l);
	73	z80_int_assert(l);
	74	break;
	75	}
	76	}
	77
	78	static void vdp_ctl_write(u8 d)
	79	{
	80	struct PicoVideo *pv = &Pico.video;
	81
	82	if (pv->pending) {
	83	if ((d >> 6) == 2) {
	84	elprintf(EL_IO, " VDP r%02x=%02x", d & 0x0f, pv->addr & 0xff);
	85	if (pv->reg[d & 0x0f] != (u8)pv->addr)
	86	vdp_reg_write(pv, d & 0x0f, pv->addr);
	87	}
	88	pv->type = d >> 6;
	89	pv->addr &= 0x00ff;
	90	pv->addr \|= (d & 0x3f) << 8;
	91	} else {
	92	pv->addr &= 0x3f00;
	93	pv->addr \|= d;
	94	}
	95	pv->pending ^= 1;
	96	}
	97
	98	static unsigned char z80_sms_in(unsigned short a)
	99	{
	100	unsigned char d = 0;
	101
	102	elprintf(EL_IO, "z80 port %04x read", a);
	103	a &= 0xc1;
	104	switch (a)
	105	{
	106	case 0x00:
	107	case 0x01:
	108	d = 0xff;
	109	break;
	110
	111	case 0x40: /* V counter */
	112	d = Pico.video.v_counter;
	113	elprintf(EL_HVCNT, "V counter read: %02x", d);
	114	break;
	115
	116	case 0x41: /* H counter */
	117	d = Pico.m.rotate++;
	118	elprintf(EL_HVCNT, "H counter read: %02x", d);
	119	break;
	120
	121	case 0x80:
	122	d = vdp_data_read();
	123	break;
	124
	125	case 0x81:
	126	d = vdp_ctl_read();
	127	break;
	128
	129	case 0xc0: /* I/O port A and B */
	130	d = ~((PicoIn.pad[0] & 0x3f) \| (PicoIn.pad[1] << 6));
	131	break;
	132
	133	case 0xc1: /* I/O port B and miscellaneous */
	134	d = (Pico.ms.io_ctl & 0x80) \| ((Pico.ms.io_ctl << 1) & 0x40) \| 0x30;
	135	d \|= ~(PicoIn.pad[1] >> 2) & 0x0f;
	136	break;
	137	}
	138
	139	elprintf(EL_IO, "ret = %02x", d);
	140	return d;
	141	}
	142
	143	static void z80_sms_out(unsigned short a, unsigned char d)
	144	{
	145	elprintf(EL_IO, "z80 port %04x write %02x", a, d);
	146	a &= 0xc1;
	147	switch (a)
	148	{
	149	case 0x01:
	150	Pico.ms.io_ctl = d;
	151	break;
	152
	153	case 0x40:
	154	case 0x41:
	155	if ((d & 0x90) == 0x90 && Pico.snd.psg_line < Pico.m.scanline)
	156	PsndDoPSG(Pico.m.scanline);
	157	SN76496Write(d);
	158	break;
	159
	160	case 0x80:
	161	vdp_data_write(d);
	162	break;
	163
	164	case 0x81:
	165	vdp_ctl_write(d);
	166	break;
	167	}
	168	}
	169
	170	static int bank_mask;
	171
	172	static void write_bank(unsigned short a, unsigned char d)
	173	{
	174	elprintf(EL_Z80BNK, "bank %04x %02x @ %04x", a, d, z80_pc());
	175	switch (a & 0x0f)
	176	{
	177	case 0x0c:
	178	elprintf(EL_STATUS\|EL_ANOMALY, "%02x written to control reg!", d);
	179	break;
	180	case 0x0d:
	181	if (d != 0)
	182	elprintf(EL_STATUS\|EL_ANOMALY, "bank0 changed to %d!", d);
	183	break;
	184	case 0x0e:
	185	d &= bank_mask;
	186	z80_map_set(z80_read_map, 0x4000, 0x7fff, Pico.rom + (d << 14), 0);
	187	#ifdef _USE_CZ80
	188	Cz80_Set_Fetch(&CZ80, 0x4000, 0x7fff, (FPTR)Pico.rom + (d << 14));
	189	#endif
	190	break;
	191	case 0x0f:
	192	d &= bank_mask;
	193	z80_map_set(z80_read_map, 0x8000, 0xbfff, Pico.rom + (d << 14), 0);
	194	#ifdef _USE_CZ80
	195	Cz80_Set_Fetch(&CZ80, 0x8000, 0xbfff, (FPTR)Pico.rom + (d << 14));
	196	#endif
	197	break;
	198	}
	199	Pico.ms.carthw[a & 0x0f] = d;
	200	}
	201
	202	static void xwrite(unsigned int a, unsigned char d)
	203	{
	204	elprintf(EL_IO, "z80 write [%04x] %02x", a, d);
	205	if (a >= 0xc000)
	206	PicoMem.zram[a & 0x1fff] = d;
	207	if (a >= 0xfff8)
	208	write_bank(a, d);
	209	}
	210
	211	void PicoResetMS(void)
	212	{
	213	z80_reset();
	214	PsndReset(); // pal must be known here
	215	}
	216
	217	void PicoPowerMS(void)
	218	{
	219	int s, tmp;
	220
	221	memset(&PicoMem,0,sizeof(PicoMem));
	222	memset(&Pico.video,0,sizeof(Pico.video));
	223	memset(&Pico.m,0,sizeof(Pico.m));
	224	Pico.m.pal = 0;
	225
	226	// calculate a mask for bank writes.
	227	// ROM loader has aligned the size for us, so this is safe.
	228	s = 0; tmp = Pico.romsize;
	229	while ((tmp >>= 1) != 0)
	230	s++;
	231	if (Pico.romsize > (1 << s))
	232	s++;
	233	tmp = 1 << s;
	234	bank_mask = (tmp - 1) >> 14;
	235
	236	Pico.ms.carthw[0x0e] = 1;
	237	Pico.ms.carthw[0x0f] = 2;
	238
	239	PicoReset();
	240	}
	241
	242	void PicoMemSetupMS(void)
	243	{
	244	z80_map_set(z80_read_map, 0x0000, 0xbfff, Pico.rom, 0);
	245	z80_map_set(z80_read_map, 0xc000, 0xdfff, PicoMem.zram, 0);
	246	z80_map_set(z80_read_map, 0xe000, 0xffff, PicoMem.zram, 0);
	247
	248	z80_map_set(z80_write_map, 0x0000, 0xbfff, xwrite, 1);
	249	z80_map_set(z80_write_map, 0xc000, 0xdfff, PicoMem.zram, 0);
	250	z80_map_set(z80_write_map, 0xe000, 0xffff, xwrite, 1);
	251
	252	#ifdef _USE_DRZ80
	253	drZ80.z80_in = z80_sms_in;
	254	drZ80.z80_out = z80_sms_out;
	255	#endif
	256	#ifdef _USE_CZ80
	257	Cz80_Set_Fetch(&CZ80, 0x0000, 0xbfff, (FPTR)Pico.rom);
	258	Cz80_Set_Fetch(&CZ80, 0xc000, 0xdfff, (FPTR)PicoMem.zram);
	259	Cz80_Set_Fetch(&CZ80, 0xe000, 0xffff, (FPTR)PicoMem.zram);
	260	Cz80_Set_INPort(&CZ80, z80_sms_in);
	261	Cz80_Set_OUTPort(&CZ80, z80_sms_out);
	262	#endif
	263	}
	264
	265	void PicoStateLoadedMS(void)
	266	{
	267	write_bank(0xfffe, Pico.ms.carthw[0x0e]);
	268	write_bank(0xffff, Pico.ms.carthw[0x0f]);
	269	}
	270
	271	void PicoFrameMS(void)
	272	{
	273	struct PicoVideo *pv = &Pico.video;
	274	int is_pal = Pico.m.pal;
	275	int lines = is_pal ? 313 : 262;
	276	int cycles_line = is_pal ? 58020 : 58293; /* (226.6 : 227.7) * 256 */
	277	int cycles_done = 0, cycles_aim = 0;
	278	int skip = PicoIn.skipFrame;
	279	int lines_vis = 192;
	280	int hint; // Hint counter
	281	int nmi;
	282	int y;
	283
	284	PsndStartFrame();
	285
	286	nmi = (PicoIn.pad[0] >> 7) & 1;
	287	if (!Pico.ms.nmi_state && nmi)
	288	z80_nmi();
	289	Pico.ms.nmi_state = nmi;
	290
	291	PicoFrameStartMode4();
	292	hint = pv->reg[0x0a];
	293
	294	for (y = 0; y < lines; y++)
	295	{
	296	pv->v_counter = Pico.m.scanline = y;
	297	if (y > 218)
	298	pv->v_counter = y - 6;
	299
	300	if (y < lines_vis && !skip)
	301	PicoLineMode4(y);
	302
	303	if (y <= lines_vis)
	304	{
	305	if (--hint < 0)
	306	{
	307	hint = pv->reg[0x0a];
	308	pv->pending_ints \|= 2;
	309	if (pv->reg[0] & 0x10) {
	310	elprintf(EL_INTS, "hint");
	311	z80_int_assert(1);
	312	}
	313	}
	314	}
	315	else if (y == lines_vis + 1) {
	316	pv->pending_ints \|= 1;
	317	if (pv->reg[1] & 0x20) {
	318	elprintf(EL_INTS, "vint");
	319	z80_int_assert(1);
	320	}
	321	}
	322
	323	// 224 because of how it's done for MD...
	324	if (y == 224 && PicoIn.sndOut)
	325	PsndGetSamplesMS();
	326
	327	cycles_aim += cycles_line;
	328	cycles_done += z80_run((cycles_aim - cycles_done) >> 8) << 8;
	329	}
	330
	331	if (PicoIn.sndOut && Pico.snd.psg_line < lines)
	332	PsndDoPSG(lines - 1);
	333	}
	334
	335	void PicoFrameDrawOnlyMS(void)
	336	{
	337	int lines_vis = 192;
	338	int y;
	339
	340	PicoFrameStartMode4();
	341
	342	for (y = 0; y < lines_vis; y++)
	343	PicoLineMode4(y);
	344	}
	345
	346	// vim:ts=2:sw=2:expandtab