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[picodrive.git] / pico / videoport.c
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cff531af 1/*\r
2 * PicoDrive\r
3 * (c) Copyright Dave, 2004\r
4 * (C) notaz, 2006-2009\r
5 *\r
6 * This work is licensed under the terms of MAME license.\r
7 * See COPYING file in the top-level directory.\r
8 */\r
cc68a136 9\r
efcba75f 10#include "pico_int.h"\r
fa1e5e29 11#include "cd/gfx_cd.h"\r
cc68a136 12\r
13extern const unsigned char hcounts_32[];\r
14extern const unsigned char hcounts_40[];\r
cc68a136 15\r
eff55556 16#ifndef UTYPES_DEFINED\r
ab0607f7 17typedef unsigned char u8;\r
cc68a136 18typedef unsigned short u16;\r
eff55556 19typedef unsigned int u32;\r
20#define UTYPES_DEFINED\r
21#endif\r
cc68a136 22\r
5de27868 23int (*PicoDmaHook)(unsigned int source, int len, unsigned short **srcp, unsigned short **limitp) = NULL;\r
cc68a136 24\r
69996cb7 25static __inline void AutoIncrement(void)\r
cc68a136 26{\r
27 Pico.video.addr=(unsigned short)(Pico.video.addr+Pico.video.reg[0xf]);\r
28}\r
29\r
30static void VideoWrite(u16 d)\r
31{\r
32 unsigned int a=Pico.video.addr;\r
33\r
34 switch (Pico.video.type)\r
35 {\r
36 case 1: if(a&1) d=(u16)((d<<8)|(d>>8)); // If address is odd, bytes are swapped (which game needs this?)\r
37 Pico.vram [(a>>1)&0x7fff]=d;\r
947fb5f9 38 if (a - ((unsigned)(Pico.video.reg[5]&0x7f) << 9) < 0x400)\r
39 rendstatus |= PDRAW_DIRTY_SPRITES;\r
40 break;\r
cc68a136 41 case 3: Pico.m.dirtyPal = 1;\r
cc68a136 42 Pico.cram [(a>>1)&0x003f]=d; break; // wraps (Desert Strike)\r
43 case 5: Pico.vsram[(a>>1)&0x003f]=d; break;\r
d26dc685 44 //default:elprintf(EL_ANOMALY, "VDP write %04x with bad type %i", d, Pico.video.type); break;\r
cc68a136 45 }\r
46\r
cc68a136 47 AutoIncrement();\r
48}\r
49\r
69996cb7 50static unsigned int VideoRead(void)\r
cc68a136 51{\r
52 unsigned int a=0,d=0;\r
53\r
54 a=Pico.video.addr; a>>=1;\r
55\r
56 switch (Pico.video.type)\r
57 {\r
58 case 0: d=Pico.vram [a&0x7fff]; break;\r
59 case 8: d=Pico.cram [a&0x003f]; break;\r
60 case 4: d=Pico.vsram[a&0x003f]; break;\r
69996cb7 61 default:elprintf(EL_ANOMALY, "VDP read with bad type %i", Pico.video.type); break;\r
cc68a136 62 }\r
4f672280 63\r
cc68a136 64 AutoIncrement();\r
65 return d;\r
66}\r
67\r
69996cb7 68static int GetDmaLength(void)\r
cc68a136 69{\r
70 struct PicoVideo *pvid=&Pico.video;\r
71 int len=0;\r
72 // 16-bit words to transfer:\r
73 len =pvid->reg[0x13];\r
74 len|=pvid->reg[0x14]<<8;\r
75 // Charles MacDonald:\r
76 if(!len) len = 0xffff;\r
77 return len;\r
78}\r
79\r
80static void DmaSlow(int len)\r
81{\r
82 u16 *pd=0, *pdend, *r;\r
83 unsigned int a=Pico.video.addr, a2, d;\r
84 unsigned char inc=Pico.video.reg[0xf];\r
672ad671 85 unsigned int source;\r
cc68a136 86\r
87 source =Pico.video.reg[0x15]<<1;\r
88 source|=Pico.video.reg[0x16]<<9;\r
89 source|=Pico.video.reg[0x17]<<17;\r
90\r
69996cb7 91 elprintf(EL_VDPDMA, "DmaSlow[%i] %06x->%04x len %i inc=%i blank %i [%i] @ %06x",\r
312e9ce1 92 Pico.video.type, source, a, len, inc, (Pico.video.status&8)||!(Pico.video.reg[1]&0x40),\r
69996cb7 93 SekCyclesDone(), SekPc);\r
cc68a136 94\r
2aa27095 95 Pico.m.dma_xfers += len;\r
96 if ((PicoAHW & PAHW_MCD) && (PicoOpt & POPT_EN_MCD_PSYNC)) SekCyclesBurn(CheckDMA());\r
ef090115 97 else SekEndTimeslice(SekCyclesLeftNoMCD - CheckDMA());\r
672ad671 98\r
ab0607f7 99 if ((source&0xe00000)==0xe00000) { // Ram\r
100 pd=(u16 *)(Pico.ram+(source&0xfffe));\r
101 pdend=(u16 *)(Pico.ram+0x10000);\r
602133e1 102 }\r
103 else if (PicoAHW & PAHW_MCD)\r
104 {\r
69996cb7 105 elprintf(EL_VDPDMA, "DmaSlow CD, r3=%02x", Pico_mcd->s68k_regs[3]);\r
ab0607f7 106 if(source<0x20000) { // Bios area\r
107 pd=(u16 *)(Pico_mcd->bios+(source&~1));\r
108 pdend=(u16 *)(Pico_mcd->bios+0x20000);\r
fa1e5e29 109 } else if ((source&0xfc0000)==0x200000) { // Word Ram\r
110 source -= 2;\r
ab0607f7 111 if (!(Pico_mcd->s68k_regs[3]&4)) { // 2M mode\r
fa1e5e29 112 pd=(u16 *)(Pico_mcd->word_ram2M+(source&0x3fffe));\r
113 pdend=(u16 *)(Pico_mcd->word_ram2M+0x40000);\r
ab0607f7 114 } else {\r
fa1e5e29 115 if (source < 0x220000) { // 1M mode\r
116 int bank = Pico_mcd->s68k_regs[3]&1;\r
117 pd=(u16 *)(Pico_mcd->word_ram1M[bank]+(source&0x1fffe));\r
118 pdend=(u16 *)(Pico_mcd->word_ram1M[bank]+0x20000);\r
69996cb7 119 } else {\r
fa1e5e29 120 DmaSlowCell(source, a, len, inc);\r
121 return;\r
69996cb7 122 }\r
ab0607f7 123 }\r
124 } else if ((source&0xfe0000)==0x020000) { // Prg Ram\r
125 u8 *prg_ram = Pico_mcd->prg_ram_b[Pico_mcd->s68k_regs[3]>>6];\r
126 pd=(u16 *)(prg_ram+(source&0x1fffe));\r
127 pdend=(u16 *)(prg_ram+0x20000);\r
128 } else {\r
03e4f2a3 129 elprintf(EL_VDPDMA|EL_ANOMALY, "DmaSlow[%i] %06x->%04x: FIXME: unsupported src", Pico.video.type, source, a);\r
ab0607f7 130 return;\r
131 }\r
602133e1 132 }\r
133 else\r
134 {\r
50483b53 135 // if we have DmaHook, let it handle ROM because of possible DMA delay\r
136 if (PicoDmaHook && PicoDmaHook(source, len, &pd, &pdend));\r
137 else if (source<Pico.romsize) { // Rom\r
ab0607f7 138 pd=(u16 *)(Pico.rom+(source&~1));\r
139 pdend=(u16 *)(Pico.rom+Pico.romsize);\r
f8ef8ff7 140 }\r
f8ef8ff7 141 else {\r
03e4f2a3 142 elprintf(EL_VDPDMA|EL_ANOMALY, "DmaSlow[%i] %06x->%04x: invalid src", Pico.video.type, source, a);\r
ab0607f7 143 return;\r
144 }\r
145 }\r
146\r
147 // overflow protection, might break something..\r
148 if (len > pdend - pd) {\r
149 len = pdend - pd;\r
69996cb7 150 elprintf(EL_VDPDMA|EL_ANOMALY, "DmaSlow overflow");\r
672ad671 151 }\r
cc68a136 152\r
153 switch (Pico.video.type)\r
154 {\r
155 case 1: // vram\r
156 r = Pico.vram;\r
cea65903 157 if (inc == 2 && !(a&1) && a+len*2 < 0x10000)\r
cc68a136 158 {\r
cea65903 159 // most used DMA mode\r
fa1e5e29 160 memcpy16(r + (a>>1), pd, len);\r
161 a += len*2;\r
cea65903 162 }\r
163 else\r
164 {\r
165 for(; len; len--)\r
166 {\r
167 d=*pd++;\r
168 if(a&1) d=(d<<8)|(d>>8);\r
169 r[a>>1] = (u16)d; // will drop the upper bits\r
170 // AutoIncrement\r
171 a=(u16)(a+inc);\r
172 // didn't src overlap?\r
173 //if(pd >= pdend) pd-=0x8000; // should be good for RAM, bad for ROM\r
174 }\r
cc68a136 175 }\r
602133e1 176 rendstatus |= PDRAW_DIRTY_SPRITES;\r
cc68a136 177 break;\r
4f672280 178\r
cc68a136 179 case 3: // cram\r
cc68a136 180 Pico.m.dirtyPal = 1;\r
181 r = Pico.cram;\r
182 for(a2=a&0x7f; len; len--)\r
183 {\r
0a051f55 184 r[a2>>1] = (u16)*pd++; // bit 0 is ignored\r
cc68a136 185 // AutoIncrement\r
186 a2+=inc;\r
187 // didn't src overlap?\r
ab0607f7 188 //if(pd >= pdend) pd-=0x8000;\r
cc68a136 189 // good dest?\r
190 if(a2 >= 0x80) break; // Todds Adventures in Slime World / Andre Agassi tennis\r
191 }\r
192 a=(a&0xff00)|a2;\r
193 break;\r
194\r
195 case 5: // vsram[a&0x003f]=d;\r
196 r = Pico.vsram;\r
197 for(a2=a&0x7f; len; len--)\r
198 {\r
199 r[a2>>1] = (u16)*pd++;\r
200 // AutoIncrement\r
201 a2+=inc;\r
202 // didn't src overlap?\r
ab0607f7 203 //if(pd >= pdend) pd-=0x8000;\r
cc68a136 204 // good dest?\r
205 if(a2 >= 0x80) break;\r
206 }\r
207 a=(a&0xff00)|a2;\r
208 break;\r
69996cb7 209\r
210 default:\r
211 elprintf(EL_VDPDMA|EL_ANOMALY, "DMA with bad type %i", Pico.video.type);\r
212 break;\r
cc68a136 213 }\r
214 // remember addr\r
215 Pico.video.addr=(u16)a;\r
216}\r
217\r
218static void DmaCopy(int len)\r
219{\r
220 u16 a=Pico.video.addr;\r
221 unsigned char *vr = (unsigned char *) Pico.vram;\r
222 unsigned char *vrs;\r
223 unsigned char inc=Pico.video.reg[0xf];\r
224 int source;\r
69996cb7 225 elprintf(EL_VDPDMA, "DmaCopy len %i [%i]", len, SekCyclesDone());\r
4f672280 226\r
69996cb7 227 Pico.m.dma_xfers += len;\r
2aa27095 228 Pico.video.status |= 2; // dma busy\r
cc68a136 229\r
230 source =Pico.video.reg[0x15];\r
231 source|=Pico.video.reg[0x16]<<8;\r
232 vrs=vr+source;\r
233\r
2aa27095 234 if (source+len > 0x10000) len=0x10000-source; // clip??\r
cc68a136 235\r
2aa27095 236 for (; len; len--)\r
cc68a136 237 {\r
238 vr[a] = *vrs++;\r
239 // AutoIncrement\r
240 a=(u16)(a+inc);\r
241 }\r
242 // remember addr\r
243 Pico.video.addr=a;\r
602133e1 244 rendstatus |= PDRAW_DIRTY_SPRITES;\r
cc68a136 245}\r
246\r
247// check: Contra, Megaman\r
248// note: this is still inaccurate\r
249static void DmaFill(int data)\r
250{\r
251 int len;\r
252 unsigned short a=Pico.video.addr;\r
253 unsigned char *vr=(unsigned char *) Pico.vram;\r
254 unsigned char high = (unsigned char) (data >> 8);\r
255 unsigned char inc=Pico.video.reg[0xf];\r
4f672280 256\r
cc68a136 257 len=GetDmaLength();\r
69996cb7 258 elprintf(EL_VDPDMA, "DmaFill len %i inc %i [%i]", len, inc, SekCyclesDone());\r
4f672280 259\r
69996cb7 260 Pico.m.dma_xfers += len;\r
2aa27095 261 Pico.video.status |= 2; // dma busy\r
cc68a136 262\r
263 // from Charles MacDonald's genvdp.txt:\r
264 // Write lower byte to address specified\r
265 vr[a] = (unsigned char) data;\r
266 a=(u16)(a+inc);\r
267\r
2aa27095 268 if (!inc) len=1;\r
cc68a136 269\r
2aa27095 270 for (; len; len--) {\r
cc68a136 271 // Write upper byte to adjacent address\r
272 // (here we are byteswapped, so address is already 'adjacent')\r
273 vr[a] = high;\r
274\r
275 // Increment address register\r
276 a=(u16)(a+inc);\r
277 }\r
278 // remember addr\r
279 Pico.video.addr=a;\r
280 // update length\r
281 Pico.video.reg[0x13] = Pico.video.reg[0x14] = 0; // Dino Dini's Soccer (E) (by Haze)\r
282\r
602133e1 283 rendstatus |= PDRAW_DIRTY_SPRITES;\r
cc68a136 284}\r
285\r
69996cb7 286static void CommandDma(void)\r
cc68a136 287{\r
288 struct PicoVideo *pvid=&Pico.video;\r
289 int len=0,method=0;\r
290\r
291 if ((pvid->reg[1]&0x10)==0) return; // DMA not enabled\r
292\r
293 len=GetDmaLength();\r
294\r
295 method=pvid->reg[0x17]>>6;\r
296 if (method< 2) DmaSlow(len); // 68000 to VDP\r
297 if (method==3) DmaCopy(len); // VRAM Copy\r
298}\r
299\r
69996cb7 300static void CommandChange(void)\r
cc68a136 301{\r
302 struct PicoVideo *pvid=&Pico.video;\r
303 unsigned int cmd=0,addr=0;\r
304\r
305 cmd=pvid->command;\r
306\r
307 // Get type of transfer 0xc0000030 (v/c/vsram read/write)\r
308 pvid->type=(unsigned char)(((cmd>>2)&0xc)|(cmd>>30));\r
309\r
310 // Get address 0x3fff0003\r
311 addr =(cmd>>16)&0x3fff;\r
312 addr|=(cmd<<14)&0xc000;\r
313 pvid->addr=(unsigned short)addr;\r
cc68a136 314\r
315 // Check for dma:\r
316 if (cmd&0x80) CommandDma();\r
317}\r
318\r
697746df 319static void DrawSync(int blank_on)\r
b6d7ac70 320{\r
321 if (Pico.m.scanline < 224 && !(PicoOpt & POPT_ALT_RENDERER) &&\r
322 !PicoSkipFrame && DrawScanline <= Pico.m.scanline) {\r
2aa27095 323 //elprintf(EL_ANOMALY, "sync");\r
b6d7ac70 324 PicoDrawSync(Pico.m.scanline, blank_on);\r
325 }\r
326}\r
327\r
eff55556 328PICO_INTERNAL_ASM void PicoVideoWrite(unsigned int a,unsigned short d)\r
cc68a136 329{\r
330 struct PicoVideo *pvid=&Pico.video;\r
331\r
2aa27095 332 //if (Pico.m.scanline < 224)\r
333 // elprintf(EL_STATUS, "PicoVideoWrite [%06x] %04x", a, d);\r
cc68a136 334 a&=0x1c;\r
335\r
336 if (a==0x00) // Data port 0 or 2\r
4f672280 337 {\r
b6d7ac70 338 // try avoiding the sync..\r
339 if (Pico.m.scanline < 224 && (pvid->reg[1]&0x40) &&\r
340 !(!pvid->pending &&\r
341 ((pvid->command & 0xc00000f0) == 0x40000010 && Pico.vsram[pvid->addr>>1] == d))\r
342 )\r
343 DrawSync(0);\r
344\r
69996cb7 345 if (pvid->pending) {\r
346 CommandChange();\r
347 pvid->pending=0;\r
348 }\r
cc68a136 349\r
350 // If a DMA fill has been set up, do it\r
351 if ((pvid->command&0x80) && (pvid->reg[1]&0x10) && (pvid->reg[0x17]>>6)==2)\r
352 {\r
353 DmaFill(d);\r
354 }\r
355 else\r
356 {\r
69996cb7 357 // preliminary FIFO emulation for Chaos Engine, The (E)\r
2aa27095 358 if (!(pvid->status&8) && (pvid->reg[1]&0x40) && !(PicoOpt&POPT_DIS_VDP_FIFO)) // active display?\r
69996cb7 359 {\r
360 pvid->status&=~0x200; // FIFO no longer empty\r
361 pvid->lwrite_cnt++;\r
362 if (pvid->lwrite_cnt >= 4) pvid->status|=0x100; // FIFO full\r
363 if (pvid->lwrite_cnt > 4) {\r
364 SekCyclesBurn(32); // penalty // 488/12-8\r
365 if (SekCycleCnt>=SekCycleAim) SekEndRun(0);\r
366 }\r
4c436138 367 elprintf(EL_ASVDP, "VDP data write: %04x [%06x] {%i} #%i @ %06x", d, Pico.video.addr,\r
368 Pico.video.type, pvid->lwrite_cnt, SekPc);\r
69996cb7 369 }\r
cc68a136 370 VideoWrite(d);\r
371 }\r
372 return;\r
373 }\r
374\r
375 if (a==0x04) // Control (command) port 4 or 6\r
376 {\r
b6d7ac70 377 if (pvid->pending)\r
cc68a136 378 {\r
b6d7ac70 379 if (d & 0x80) DrawSync(0); // only need sync for DMA\r
cc68a136 380 // Low word of command:\r
381 pvid->command&=0xffff0000;\r
382 pvid->command|=d;\r
383 pvid->pending=0;\r
384 CommandChange();\r
602133e1 385 }\r
386 else\r
387 {\r
388 if ((d&0xc000)==0x8000)\r
cc68a136 389 {\r
390 // Register write:\r
391 int num=(d>>8)&0x1f;\r
0ffefdb8 392 int dold=pvid->reg[num];\r
147f8df1 393 int blank_on = 0;\r
602133e1 394 pvid->type=0; // register writes clear command (else no Sega logo in Golden Axe II)\r
0ffefdb8 395 if (num > 0x0a && !(pvid->reg[1]&4)) {\r
396 elprintf(EL_ANOMALY, "%02x written to reg %02x in SMS mode @ %06x", d, num, SekPc);\r
602133e1 397 return;\r
b6d7ac70 398 }\r
602133e1 399\r
147f8df1 400 if (num == 1 && !(d&0x40) && SekCyclesLeft > 390) blank_on = 1;\r
401 DrawSync(blank_on);\r
402 pvid->reg[num]=(unsigned char)d;\r
602133e1 403 switch (num)\r
404 {\r
405 case 0x00:\r
406 elprintf(EL_INTSW, "hint_onoff: %i->%i [%i] pend=%i @ %06x", (dold&0x10)>>4,\r
407 (d&0x10)>>4, SekCyclesDone(), (pvid->pending_ints&0x10)>>4, SekPc);\r
147f8df1 408 goto update_irq;\r
602133e1 409 case 0x01:\r
410 elprintf(EL_INTSW, "vint_onoff: %i->%i [%i] pend=%i @ %06x", (dold&0x20)>>5,\r
411 (d&0x20)>>5, SekCyclesDone(), (pvid->pending_ints&0x20)>>5, SekPc);\r
147f8df1 412 goto update_irq;\r
602133e1 413 case 0x05:\r
4c436138 414 //elprintf(EL_STATUS, "spritep moved to %04x", (unsigned)(Pico.video.reg[5]&0x7f) << 9);\r
602133e1 415 if (d^dold) rendstatus |= PDRAW_SPRITES_MOVED;\r
416 break;\r
417 case 0x0c:\r
418 // renderers should update their palettes if sh/hi mode is changed\r
419 if ((d^dold)&8) Pico.m.dirtyPal = 2;\r
420 break;\r
421 }\r
147f8df1 422 return;\r
602133e1 423\r
147f8df1 424update_irq:\r
03e4f2a3 425#ifndef EMU_CORE_DEBUG\r
b6d7ac70 426 // update IRQ level\r
602133e1 427 if (!SekShouldInterrupt) // hack\r
03e4f2a3 428 {\r
602133e1 429 int lines, pints, irq=0;\r
430 lines = (pvid->reg[1] & 0x20) | (pvid->reg[0] & 0x10);\r
431 pints = (pvid->pending_ints&lines);\r
b6d7ac70 432 if (pints & 0x20) irq = 6;\r
433 else if (pints & 0x10) irq = 4;\r
602133e1 434 SekInterrupt(irq); // update line\r
435\r
2aa27095 436 if (irq) SekEndRun(24); // make it delayed\r
cc68a136 437 }\r
cc68a136 438#endif\r
602133e1 439 }\r
440 else\r
441 {\r
cc68a136 442 // High word of command:\r
443 pvid->command&=0x0000ffff;\r
444 pvid->command|=d<<16;\r
445 pvid->pending=1;\r
446 }\r
447 }\r
448 }\r
449}\r
450\r
eff55556 451PICO_INTERNAL_ASM unsigned int PicoVideoRead(unsigned int a)\r
cc68a136 452{\r
cc68a136 453 a&=0x1c;\r
454\r
cc68a136 455 if (a==0x04) // control port\r
456 {\r
69996cb7 457 struct PicoVideo *pv=&Pico.video;\r
b6d7ac70 458 unsigned int d;\r
69996cb7 459 d=pv->status;\r
9761a7d0 460 //if (PicoOpt&POPT_ALT_RENDERER) d|=0x0020; // sprite collision (Shadow of the Beast)\r
602133e1 461 if (SekCyclesLeft < 84+4) d|=0x0004; // H-Blank (Sonic3 vs)\r
69996cb7 462\r
9761a7d0 463 d |= ((pv->reg[1]&0x40)^0x40) >> 3; // set V-Blank if display is disabled\r
464 d |= (pv->pending_ints&0x20)<<2; // V-int pending?\r
69996cb7 465 if (d&0x100) pv->status&=~0x100; // FIFO no longer full\r
cc68a136 466\r
9761a7d0 467 pv->pending = 0; // ctrl port reads clear write-pending flag (Charles MacDonald)\r
cc68a136 468\r
69996cb7 469 elprintf(EL_SR, "SR read: %04x @ %06x", d, SekPc);\r
b6d7ac70 470 return d;\r
cc68a136 471 }\r
472\r
473 // H-counter info (based on Generator):\r
474 // frame:\r
475 // | <- hblank? -> |\r
476 // start <416> hint <36> hdisplay <38> end // CPU cycles\r
477 // |---------...---------|------------|-------------|\r
478 // 0 B6 E4 FF // 40 cells\r
479 // 0 93 E8 FF // 32 cells\r
480\r
481 // Gens (?) v-render\r
482 // start <hblank=84> hint hdisplay <404> |\r
483 // |---------------------|--------------------------|\r
484 // E4 (hc[0x43]==0) 07 B1 // 40\r
485 // E8 (hc[0x45]==0) 05 91 // 32\r
4f672280 486\r
cc68a136 487 // check: Sonic 3D Blast bonus, Cannon Fodder, Chase HQ II, 3 Ninjas kick back, Road Rash 3, Skitchin', Wheel of Fortune\r
488 if ((a&0x1c)==0x08)\r
489 {\r
9761a7d0 490 unsigned int d;\r
2aa27095 491 int lineCycles;\r
947fb5f9 492\r
2aa27095 493 lineCycles = (488-SekCyclesLeft)&0x1ff;\r
2aa27095 494 if (Pico.video.reg[12]&1)\r
9761a7d0 495 d = hcounts_40[lineCycles];\r
496 else d = hcounts_32[lineCycles];\r
cc68a136 497\r
9761a7d0 498 elprintf(EL_HVCNT, "hv: %02x %02x (%i) @ %06x", d, Pico.video.v_counter, SekCyclesDone(), SekPc);\r
499 return d | (Pico.video.v_counter << 8);\r
500 }\r
cc68a136 501\r
9761a7d0 502 if (a==0x00) // data port\r
503 {\r
504 return VideoRead();\r
505 }\r
cc68a136 506\r
9761a7d0 507 return 0;\r
508}\r
509\r
510unsigned int PicoVideoRead8(unsigned int a)\r
511{\r
512 unsigned int d;\r
513 a&=0x1d;\r
514\r
515 switch (a)\r
516 {\r
517 case 0: return VideoRead() >> 8;\r
518 case 1: return VideoRead() & 0xff;\r
519 case 4: // control port/status reg\r
520 d = Pico.video.status >> 8;\r
521 if (d&1) Pico.video.status&=~0x100; // FIFO no longer full\r
522 Pico.video.pending = 0;\r
523 elprintf(EL_SR, "SR read (h): %02x @ %06x", d, SekPc);\r
524 return d;\r
525 case 5:\r
526 d = Pico.video.status & 0xff;\r
527 //if (PicoOpt&POPT_ALT_RENDERER) d|=0x0020; // sprite collision (Shadow of the Beast)\r
528 d |= ((Pico.video.reg[1]&0x40)^0x40) >> 3; // set V-Blank if display is disabled\r
529 d |= (Pico.video.pending_ints&0x20)<<2; // V-int pending?\r
530 if (SekCyclesLeft < 84+4) d |= 4; // H-Blank\r
531 Pico.video.pending = 0;\r
532 elprintf(EL_SR, "SR read (l): %02x @ %06x", d, SekPc);\r
533 return d;\r
534 case 8: // hv counter\r
535 elprintf(EL_HVCNT, "vcounter: %02x (%i) @ %06x", Pico.video.v_counter, SekCyclesDone(), SekPc);\r
536 return Pico.video.v_counter;\r
537 case 9:\r
538 d = (488-SekCyclesLeft)&0x1ff;\r
539 if (Pico.video.reg[12]&1)\r
540 d = hcounts_40[d];\r
541 else d = hcounts_32[d];\r
542 elprintf(EL_HVCNT, "hcounter: %02x (%i) @ %06x", d, SekCyclesDone(), SekPc);\r
543 return d;\r
cc68a136 544 }\r
545\r
b6d7ac70 546 return 0;\r
cc68a136 547}\r
fast MegaDrive/MegaCD/32X emulator