87b0845f |
1 | /* |
2 | * TODO: |
3 | * - start in a state as if BIOS ran |
4 | * - remaining status flags (OVR/COL) |
5 | * - RAM support in mapper |
6 | * - region support |
7 | * - Pause button (NMI) |
8 | * - SN76496 DAC-like usage |
9 | * - H counter |
10 | */ |
3e49ffd0 |
11 | #include "pico_int.h" |
2ec9bec5 |
12 | #include "sound/sn76496.h" |
3e49ffd0 |
13 | |
2ec9bec5 |
14 | static unsigned char vdp_data_read(void) |
3e49ffd0 |
15 | { |
2ec9bec5 |
16 | struct PicoVideo *pv = &Pico.video; |
17 | unsigned char d; |
18 | |
19 | d = Pico.vramb[pv->addr]; |
20 | pv->addr = (pv->addr + 1) & 0x3fff; |
21 | pv->pending = 0; |
22 | return d; |
23 | } |
24 | |
25 | static unsigned char vdp_ctl_read(void) |
26 | { |
27 | unsigned char d = Pico.video.pending_ints << 7; |
28 | Pico.video.pending = 0; |
29 | Pico.video.pending_ints = 0; |
30 | |
31 | elprintf(EL_SR, "VDP sr: %02x", d); |
32 | return d; |
33 | } |
34 | |
35 | static void vdp_data_write(unsigned char d) |
36 | { |
37 | struct PicoVideo *pv = &Pico.video; |
38 | |
39 | if (pv->type == 3) { |
40 | Pico.cram[pv->addr & 0x1f] = d; |
200772b7 |
41 | Pico.m.dirtyPal = 1; |
2ec9bec5 |
42 | } else { |
43 | Pico.vramb[pv->addr] = d; |
44 | } |
45 | pv->addr = (pv->addr + 1) & 0x3fff; |
2ec9bec5 |
46 | |
47 | pv->pending = 0; |
48 | } |
49 | |
50 | static void vdp_ctl_write(unsigned char d) |
51 | { |
52 | struct PicoVideo *pv = &Pico.video; |
53 | |
54 | if (pv->pending) { |
55 | if ((d >> 6) == 2) { |
56 | pv->reg[d & 0x0f] = pv->addr; |
200772b7 |
57 | elprintf(EL_IO, " VDP r%02x=%02x", d & 0x0f, pv->addr & 0xff); |
2ec9bec5 |
58 | } |
59 | pv->type = d >> 6; |
60 | pv->addr &= 0x00ff; |
61 | pv->addr |= (d & 0x3f) << 8; |
62 | } else { |
63 | pv->addr &= 0x3f00; |
64 | pv->addr |= d; |
65 | } |
66 | pv->pending ^= 1; |
3e49ffd0 |
67 | } |
68 | |
2ec9bec5 |
69 | static unsigned char z80_sms_in(unsigned short a) |
3e49ffd0 |
70 | { |
2ec9bec5 |
71 | unsigned char d = 0; |
72 | |
200772b7 |
73 | elprintf(EL_IO, "z80 port %04x read", a); |
2ec9bec5 |
74 | a &= 0xc1; |
75 | switch (a) |
76 | { |
77 | case 0x00: |
78 | case 0x01: |
79 | d = 0xff; |
80 | break; |
81 | |
82 | case 0x40: /* V counter */ |
83 | d = Pico.video.v_counter; |
87b0845f |
84 | elprintf(EL_HVCNT, "V counter read: %02x", d); |
2ec9bec5 |
85 | break; |
86 | |
87 | case 0x41: /* H counter */ |
88 | d = Pico.m.rotate++; |
87b0845f |
89 | elprintf(EL_HVCNT, "H counter read: %02x", d); |
2ec9bec5 |
90 | break; |
91 | |
92 | case 0x80: |
93 | d = vdp_data_read(); |
94 | break; |
95 | |
96 | case 0x81: |
97 | d = vdp_ctl_read(); |
98 | break; |
99 | |
100 | case 0xc0: /* I/O port A and B */ |
101 | d = ~((PicoPad[0] & 0x3f) | (PicoPad[1] << 6)); |
102 | break; |
103 | |
104 | case 0xc1: /* I/O port B and miscellaneous */ |
105 | d = (Pico.sms_io_ctl & 0x80) | ((Pico.sms_io_ctl << 1) & 0x40) | 0x30; |
106 | d |= ~(PicoPad[1] >> 2) & 0x0f; |
107 | break; |
108 | } |
109 | |
200772b7 |
110 | elprintf(EL_IO, "ret = %02x", d); |
2ec9bec5 |
111 | return d; |
112 | } |
113 | |
114 | static void z80_sms_out(unsigned short a, unsigned char d) |
115 | { |
200772b7 |
116 | elprintf(EL_IO, "z80 port %04x write %02x", a, d); |
2ec9bec5 |
117 | a &= 0xc1; |
118 | switch (a) |
119 | { |
120 | case 0x01: |
121 | Pico.sms_io_ctl = d; |
122 | break; |
123 | |
124 | case 0x40: |
125 | case 0x41: |
126 | if (PicoOpt & POPT_EN_PSG) |
127 | SN76496Write(d); |
128 | break; |
129 | |
130 | case 0x80: |
131 | vdp_data_write(d); |
132 | break; |
133 | |
134 | case 0x81: |
135 | vdp_ctl_write(d); |
136 | break; |
137 | } |
138 | } |
139 | |
87b0845f |
140 | static int bank_mask; |
141 | |
2ec9bec5 |
142 | static void write_bank(unsigned short a, unsigned char d) |
143 | { |
460603fa |
144 | elprintf(EL_Z80BNK, "bank %04x %02x @ %04x", a, d, z80_pc()); |
2ec9bec5 |
145 | switch (a & 0x0f) |
146 | { |
147 | case 0x0c: |
87b0845f |
148 | elprintf(EL_STATUS|EL_ANOMALY, "%02x written to control reg!", d); |
2ec9bec5 |
149 | break; |
150 | case 0x0d: |
151 | if (d != 0) |
152 | elprintf(EL_STATUS|EL_ANOMALY, "bank0 changed to %d!", d); |
153 | break; |
154 | case 0x0e: |
87b0845f |
155 | d &= bank_mask; |
2ec9bec5 |
156 | z80_map_set(z80_read_map, 0x4000, 0x7fff, Pico.rom + (d << 14), 0); |
157 | #ifdef _USE_CZ80 |
158 | Cz80_Set_Fetch(&CZ80, 0x4000, 0x7fff, (UINT32)Pico.rom + (d << 14)); |
159 | #endif |
160 | break; |
161 | case 0x0f: |
87b0845f |
162 | d &= bank_mask; |
2ec9bec5 |
163 | z80_map_set(z80_read_map, 0x8000, 0xbfff, Pico.rom + (d << 14), 0); |
164 | #ifdef _USE_CZ80 |
165 | Cz80_Set_Fetch(&CZ80, 0x8000, 0xbfff, (UINT32)Pico.rom + (d << 14)); |
166 | #endif |
167 | break; |
168 | } |
3e49ffd0 |
169 | } |
170 | |
2ec9bec5 |
171 | static void MEMH_FUNC xwrite(unsigned int a, unsigned char d) |
172 | { |
200772b7 |
173 | elprintf(EL_IO, "z80 write [%04x] %02x", a, d); |
2ec9bec5 |
174 | if (a >= 0xc000) |
175 | Pico.zram[a & 0x1fff] = d; |
176 | if (a >= 0xfff0) |
177 | write_bank(a, d); |
3e49ffd0 |
178 | } |
179 | |
2ec9bec5 |
180 | void PicoResetMS(void) |
3e49ffd0 |
181 | { |
2ec9bec5 |
182 | z80_reset(); |
183 | PsndReset(); // pal must be known here |
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184 | } |
185 | |
186 | void PicoPowerMS(void) |
187 | { |
87b0845f |
188 | int s, tmp; |
189 | |
2ec9bec5 |
190 | memset(&Pico.ram,0,(unsigned int)&Pico.rom-(unsigned int)&Pico.ram); |
191 | memset(&Pico.video,0,sizeof(Pico.video)); |
192 | memset(&Pico.m,0,sizeof(Pico.m)); |
193 | Pico.m.pal = 0; |
194 | |
87b0845f |
195 | // calculate a mask for bank writes. |
196 | // ROM loader has aligned the size for us, so this is safe. |
197 | s = 0; tmp = Pico.romsize; |
198 | while ((tmp >>= 1) != 0) |
199 | s++; |
200 | if (Pico.romsize > (1 << s)) |
201 | s++; |
202 | tmp = 1 << s; |
203 | bank_mask = (tmp - 1) >> 14; |
204 | |
2ec9bec5 |
205 | PicoReset(); |
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206 | } |
207 | |
208 | void PicoMemSetupMS(void) |
209 | { |
210 | z80_map_set(z80_read_map, 0x0000, 0xbfff, Pico.rom, 0); |
211 | z80_map_set(z80_read_map, 0xc000, 0xdfff, Pico.zram, 0); |
200772b7 |
212 | z80_map_set(z80_read_map, 0xe000, 0xffff, Pico.zram, 0); |
3e49ffd0 |
213 | |
2ec9bec5 |
214 | z80_map_set(z80_write_map, 0x0000, 0xbfff, xwrite, 1); |
3e49ffd0 |
215 | z80_map_set(z80_write_map, 0xc000, 0xdfff, Pico.zram, 0); |
216 | z80_map_set(z80_write_map, 0xe000, 0xffff, xwrite, 1); |
217 | |
218 | #ifdef _USE_DRZ80 |
219 | drZ80.z80_in = z80_sms_in; |
220 | drZ80.z80_out = z80_sms_out; |
221 | #endif |
222 | #ifdef _USE_CZ80 |
223 | Cz80_Set_Fetch(&CZ80, 0x0000, 0xbfff, (UINT32)Pico.rom); |
224 | Cz80_Set_Fetch(&CZ80, 0xc000, 0xdfff, (UINT32)Pico.zram); |
2ec9bec5 |
225 | Cz80_Set_Fetch(&CZ80, 0xe000, 0xffff, (UINT32)Pico.zram); |
3e49ffd0 |
226 | Cz80_Set_INPort(&CZ80, z80_sms_in); |
227 | Cz80_Set_OUTPort(&CZ80, z80_sms_out); |
228 | #endif |
229 | } |
230 | |
231 | void PicoFrameMS(void) |
232 | { |
2ec9bec5 |
233 | struct PicoVideo *pv = &Pico.video; |
234 | int is_pal = Pico.m.pal; |
235 | int lines = is_pal ? 313 : 262; |
236 | int cycles_line = is_pal ? 58020 : 58293; /* (226.6 : 227.7) * 256 */ |
237 | int cycles_done = 0, cycles_aim = 0; |
19954be1 |
238 | int skip = PicoSkipFrame; |
2ec9bec5 |
239 | int lines_vis = 192; |
87b0845f |
240 | int hint; // Hint counter |
2ec9bec5 |
241 | int y; |
242 | |
200772b7 |
243 | PicoFrameStartMode4(); |
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244 | hint = pv->reg[0x0a]; |
200772b7 |
245 | |
2ec9bec5 |
246 | for (y = 0; y < lines; y++) |
247 | { |
248 | pv->v_counter = Pico.m.scanline = y; |
249 | |
19954be1 |
250 | if (y < lines_vis && !skip) |
200772b7 |
251 | PicoLineMode4(y); |
87b0845f |
252 | |
253 | if (y <= lines_vis) |
254 | { |
255 | if (--hint < 0) |
256 | { |
257 | hint = pv->reg[0x0a]; |
258 | pv->pending_ints |= 2; |
259 | if (pv->reg[0] & 0x10) { |
260 | elprintf(EL_INTS, "hint"); |
261 | z80_int(); |
262 | } |
263 | } |
264 | } |
200772b7 |
265 | else if (y == lines_vis + 1) { |
87b0845f |
266 | pv->pending_ints |= 1; |
267 | if (pv->reg[1] & 0x20) { |
2ec9bec5 |
268 | elprintf(EL_INTS, "vint"); |
269 | z80_int(); |
270 | } |
271 | } |
272 | |
273 | cycles_aim += cycles_line; |
274 | cycles_done += z80_run((cycles_aim - cycles_done) >> 8) << 8; |
275 | } |
276 | |
460603fa |
277 | if (PsndOut) |
278 | PsndGetSamplesMS(); |
3e49ffd0 |
279 | } |
280 | |
87b0845f |
281 | void PicoFrameDrawOnlyMS(void) |
282 | { |
283 | int lines_vis = 192; |
284 | int y; |
285 | |
286 | PicoFrameStartMode4(); |
287 | |
288 | for (y = 0; y < lines_vis; y++) |
289 | PicoLineMode4(y); |
290 | } |
291 | |