cff531af |
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 | */ |
87b0845f |
8 | /* |
9 | * TODO: |
10 | * - start in a state as if BIOS ran |
87b0845f |
11 | * - RAM support in mapper |
12 | * - region support |
87b0845f |
13 | * - H counter |
14 | */ |
3e49ffd0 |
15 | #include "pico_int.h" |
af37bca8 |
16 | #include "memory.h" |
2ec9bec5 |
17 | #include "sound/sn76496.h" |
3e49ffd0 |
18 | |
2ec9bec5 |
19 | static unsigned char vdp_data_read(void) |
3e49ffd0 |
20 | { |
2ec9bec5 |
21 | struct PicoVideo *pv = &Pico.video; |
22 | unsigned char d; |
23 | |
88fd63ad |
24 | d = PicoMem.vramb[pv->addr]; |
2ec9bec5 |
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 | { |
1c25c32c |
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; |
2ec9bec5 |
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) { |
88fd63ad |
48 | PicoMem.cram[pv->addr & 0x1f] = d; |
200772b7 |
49 | Pico.m.dirtyPal = 1; |
2ec9bec5 |
50 | } else { |
88fd63ad |
51 | PicoMem.vramb[pv->addr] = d; |
2ec9bec5 |
52 | } |
53 | pv->addr = (pv->addr + 1) & 0x3fff; |
2ec9bec5 |
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; |
200772b7 |
65 | elprintf(EL_IO, " VDP r%02x=%02x", d & 0x0f, pv->addr & 0xff); |
2ec9bec5 |
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; |
3e49ffd0 |
75 | } |
76 | |
2ec9bec5 |
77 | static unsigned char z80_sms_in(unsigned short a) |
3e49ffd0 |
78 | { |
2ec9bec5 |
79 | unsigned char d = 0; |
80 | |
200772b7 |
81 | elprintf(EL_IO, "z80 port %04x read", a); |
2ec9bec5 |
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; |
87b0845f |
92 | elprintf(EL_HVCNT, "V counter read: %02x", d); |
2ec9bec5 |
93 | break; |
94 | |
95 | case 0x41: /* H counter */ |
96 | d = Pico.m.rotate++; |
87b0845f |
97 | elprintf(EL_HVCNT, "H counter read: %02x", d); |
2ec9bec5 |
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 */ |
93f9619e |
109 | d = ~((PicoIn.pad[0] & 0x3f) | (PicoIn.pad[1] << 6)); |
2ec9bec5 |
110 | break; |
111 | |
112 | case 0xc1: /* I/O port B and miscellaneous */ |
b4db550e |
113 | d = (Pico.ms.io_ctl & 0x80) | ((Pico.ms.io_ctl << 1) & 0x40) | 0x30; |
93f9619e |
114 | d |= ~(PicoIn.pad[1] >> 2) & 0x0f; |
2ec9bec5 |
115 | break; |
116 | } |
117 | |
200772b7 |
118 | elprintf(EL_IO, "ret = %02x", d); |
2ec9bec5 |
119 | return d; |
120 | } |
121 | |
122 | static void z80_sms_out(unsigned short a, unsigned char d) |
123 | { |
200772b7 |
124 | elprintf(EL_IO, "z80 port %04x write %02x", a, d); |
2ec9bec5 |
125 | a &= 0xc1; |
126 | switch (a) |
127 | { |
128 | case 0x01: |
b4db550e |
129 | Pico.ms.io_ctl = d; |
2ec9bec5 |
130 | break; |
131 | |
132 | case 0x40: |
133 | case 0x41: |
6311a3ba |
134 | if ((d & 0x90) == 0x90 && Pico.snd.psg_line < Pico.m.scanline) |
075672bf |
135 | PsndDoPSG(Pico.m.scanline); |
136 | SN76496Write(d); |
2ec9bec5 |
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 | |
87b0845f |
149 | static int bank_mask; |
150 | |
2ec9bec5 |
151 | static void write_bank(unsigned short a, unsigned char d) |
152 | { |
460603fa |
153 | elprintf(EL_Z80BNK, "bank %04x %02x @ %04x", a, d, z80_pc()); |
2ec9bec5 |
154 | switch (a & 0x0f) |
155 | { |
156 | case 0x0c: |
87b0845f |
157 | elprintf(EL_STATUS|EL_ANOMALY, "%02x written to control reg!", d); |
2ec9bec5 |
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: |
87b0845f |
164 | d &= bank_mask; |
2ec9bec5 |
165 | z80_map_set(z80_read_map, 0x4000, 0x7fff, Pico.rom + (d << 14), 0); |
166 | #ifdef _USE_CZ80 |
b8a1c09a |
167 | Cz80_Set_Fetch(&CZ80, 0x4000, 0x7fff, (FPTR)Pico.rom + (d << 14)); |
2ec9bec5 |
168 | #endif |
169 | break; |
170 | case 0x0f: |
87b0845f |
171 | d &= bank_mask; |
2ec9bec5 |
172 | z80_map_set(z80_read_map, 0x8000, 0xbfff, Pico.rom + (d << 14), 0); |
173 | #ifdef _USE_CZ80 |
b8a1c09a |
174 | Cz80_Set_Fetch(&CZ80, 0x8000, 0xbfff, (FPTR)Pico.rom + (d << 14)); |
2ec9bec5 |
175 | #endif |
176 | break; |
177 | } |
b4db550e |
178 | Pico.ms.carthw[a & 0x0f] = d; |
3e49ffd0 |
179 | } |
180 | |
553c3eaa |
181 | static void xwrite(unsigned int a, unsigned char d) |
2ec9bec5 |
182 | { |
200772b7 |
183 | elprintf(EL_IO, "z80 write [%04x] %02x", a, d); |
2ec9bec5 |
184 | if (a >= 0xc000) |
88fd63ad |
185 | PicoMem.zram[a & 0x1fff] = d; |
b4db550e |
186 | if (a >= 0xfff8) |
2ec9bec5 |
187 | write_bank(a, d); |
3e49ffd0 |
188 | } |
189 | |
2ec9bec5 |
190 | void PicoResetMS(void) |
3e49ffd0 |
191 | { |
2ec9bec5 |
192 | z80_reset(); |
193 | PsndReset(); // pal must be known here |
3e49ffd0 |
194 | } |
195 | |
196 | void PicoPowerMS(void) |
197 | { |
87b0845f |
198 | int s, tmp; |
199 | |
88fd63ad |
200 | memset(&PicoMem,0,sizeof(PicoMem)); |
2ec9bec5 |
201 | memset(&Pico.video,0,sizeof(Pico.video)); |
202 | memset(&Pico.m,0,sizeof(Pico.m)); |
203 | Pico.m.pal = 0; |
204 | |
87b0845f |
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 | |
b4db550e |
215 | Pico.ms.carthw[0x0e] = 1; |
216 | Pico.ms.carthw[0x0f] = 2; |
217 | |
2ec9bec5 |
218 | PicoReset(); |
3e49ffd0 |
219 | } |
220 | |
221 | void PicoMemSetupMS(void) |
222 | { |
223 | z80_map_set(z80_read_map, 0x0000, 0xbfff, Pico.rom, 0); |
88fd63ad |
224 | z80_map_set(z80_read_map, 0xc000, 0xdfff, PicoMem.zram, 0); |
225 | z80_map_set(z80_read_map, 0xe000, 0xffff, PicoMem.zram, 0); |
3e49ffd0 |
226 | |
2ec9bec5 |
227 | z80_map_set(z80_write_map, 0x0000, 0xbfff, xwrite, 1); |
88fd63ad |
228 | z80_map_set(z80_write_map, 0xc000, 0xdfff, PicoMem.zram, 0); |
3e49ffd0 |
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 |
b8a1c09a |
236 | Cz80_Set_Fetch(&CZ80, 0x0000, 0xbfff, (FPTR)Pico.rom); |
88fd63ad |
237 | Cz80_Set_Fetch(&CZ80, 0xc000, 0xdfff, (FPTR)PicoMem.zram); |
238 | Cz80_Set_Fetch(&CZ80, 0xe000, 0xffff, (FPTR)PicoMem.zram); |
3e49ffd0 |
239 | Cz80_Set_INPort(&CZ80, z80_sms_in); |
240 | Cz80_Set_OUTPort(&CZ80, z80_sms_out); |
241 | #endif |
242 | } |
243 | |
b4db550e |
244 | void PicoStateLoadedMS(void) |
245 | { |
246 | write_bank(0xfffe, Pico.ms.carthw[0x0e]); |
247 | write_bank(0xffff, Pico.ms.carthw[0x0f]); |
248 | } |
249 | |
3e49ffd0 |
250 | void PicoFrameMS(void) |
251 | { |
2ec9bec5 |
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; |
93f9619e |
257 | int skip = PicoIn.skipFrame; |
2ec9bec5 |
258 | int lines_vis = 192; |
87b0845f |
259 | int hint; // Hint counter |
835122bc |
260 | int nmi; |
2ec9bec5 |
261 | int y; |
262 | |
4f2cdbf5 |
263 | PsndStartFrame(); |
264 | |
93f9619e |
265 | nmi = (PicoIn.pad[0] >> 7) & 1; |
835122bc |
266 | if (!Pico.ms.nmi_state && nmi) |
267 | z80_nmi(); |
268 | Pico.ms.nmi_state = nmi; |
269 | |
200772b7 |
270 | PicoFrameStartMode4(); |
87b0845f |
271 | hint = pv->reg[0x0a]; |
200772b7 |
272 | |
2ec9bec5 |
273 | for (y = 0; y < lines; y++) |
274 | { |
275 | pv->v_counter = Pico.m.scanline = y; |
03065bb6 |
276 | if (y > 218) |
277 | pv->v_counter = y - 6; |
2ec9bec5 |
278 | |
19954be1 |
279 | if (y < lines_vis && !skip) |
200772b7 |
280 | PicoLineMode4(y); |
87b0845f |
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 | } |
200772b7 |
294 | else if (y == lines_vis + 1) { |
87b0845f |
295 | pv->pending_ints |= 1; |
296 | if (pv->reg[1] & 0x20) { |
2ec9bec5 |
297 | elprintf(EL_INTS, "vint"); |
298 | z80_int(); |
299 | } |
300 | } |
301 | |
075672bf |
302 | // 224 because of how it's done for MD... |
6311a3ba |
303 | if (y == 224 && PicoIn.sndOut) |
075672bf |
304 | PsndGetSamplesMS(); |
305 | |
2ec9bec5 |
306 | cycles_aim += cycles_line; |
307 | cycles_done += z80_run((cycles_aim - cycles_done) >> 8) << 8; |
308 | } |
309 | |
6311a3ba |
310 | if (PicoIn.sndOut && Pico.snd.psg_line < lines) |
075672bf |
311 | PsndDoPSG(lines - 1); |
3e49ffd0 |
312 | } |
313 | |
87b0845f |
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 | |
075672bf |
325 | // vim:ts=2:sw=2:expandtab |