| 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 |