| 1 | \r |
| 2 | // This file is part of the PicoDrive Megadrive Emulator\r |
| 3 | \r |
| 4 | // Copyright (c) 2011 FinalDave (emudave (at) gmail.com)\r |
| 5 | \r |
| 6 | // This code is licensed under the GNU General Public License version 2.0 and the MAME License.\r |
| 7 | // You can choose the license that has the most advantages for you.\r |
| 8 | \r |
| 9 | // SVN repository can be found at http://code.google.com/p/cyclone68000/\r |
| 10 | \r |
| 11 | #include "PicoInt.h"\r |
| 12 | \r |
| 13 | int PicoVer=0x0030;\r |
| 14 | struct Pico Pico;\r |
| 15 | int PicoOpt=0;\r |
| 16 | \r |
| 17 | int PicoPad[2]; // Joypads, format is SACB RLDU\r |
| 18 | \r |
| 19 | int PicoInit()\r |
| 20 | {\r |
| 21 | // Blank space for state:\r |
| 22 | memset(&Pico,0,sizeof(Pico));\r |
| 23 | memset(&PicoPad,0,sizeof(PicoPad));\r |
| 24 | Pico.m.dirtyPal=1;\r |
| 25 | \r |
| 26 | // Init CPU:\r |
| 27 | SekInit();\r |
| 28 | \r |
| 29 | // Setup memory callbacks:\r |
| 30 | PicoMemInit();\r |
| 31 | PsndReset();\r |
| 32 | \r |
| 33 | #ifdef MSOUND\r |
| 34 | YM2612Init(1,7670443,PsndRate,NULL,NULL);\r |
| 35 | #endif\r |
| 36 | return 0;\r |
| 37 | }\r |
| 38 | \r |
| 39 | void PicoExit()\r |
| 40 | {\r |
| 41 | #ifdef MSOUND\r |
| 42 | YM2612Shutdown();\r |
| 43 | #endif\r |
| 44 | \r |
| 45 | memset(&Pico,0,sizeof(Pico));\r |
| 46 | }\r |
| 47 | \r |
| 48 | int PicoReset()\r |
| 49 | {\r |
| 50 | unsigned int region=0;\r |
| 51 | int support=0,hw=0,i=0;\r |
| 52 | unsigned char pal=0;\r |
| 53 | \r |
| 54 | if (Pico.romsize<=0) return 1;\r |
| 55 | \r |
| 56 | SekReset();\r |
| 57 | PsndReset();\r |
| 58 | #ifdef MSOUND\r |
| 59 | YM2612ResetChip(0);\r |
| 60 | #endif\r |
| 61 | \r |
| 62 | // Read cartridge region data:\r |
| 63 | region=PicoRead32(0x1f0);\r |
| 64 | \r |
| 65 | for (i=0;i<4;i++)\r |
| 66 | {\r |
| 67 | int c=0;\r |
| 68 | \r |
| 69 | c=region>>(i<<3); c&=0xff;\r |
| 70 | if (c<=' ') continue;\r |
| 71 | \r |
| 72 | if (c=='J') support|=1;\r |
| 73 | else if (c=='U') support|=4;\r |
| 74 | else if (c=='E') support|=8;\r |
| 75 | else\r |
| 76 | {\r |
| 77 | // New style code:\r |
| 78 | char s[2]={0,0};\r |
| 79 | s[0]=(char)c;\r |
| 80 | support|=strtol(s,NULL,16);\r |
| 81 | }\r |
| 82 | \r |
| 83 | }\r |
| 84 | \r |
| 85 | // Try to pick the best hardware value for English/60hz:\r |
| 86 | if (support&4) hw=0x80; // USA\r |
| 87 | else if (support&8) { hw=0xc0; pal=1; } // Europe\r |
| 88 | else if (support&1) hw=0x00; // Japan NTSC\r |
| 89 | else if (support&2) { hw=0x40; pal=1; } // Japan PAL\r |
| 90 | else hw=0x80; // USA\r |
| 91 | \r |
| 92 | Pico.m.hardware=(unsigned char)(hw|0x20); // No disk attached\r |
| 93 | Pico.m.pal=pal;\r |
| 94 | \r |
| 95 | return 0;\r |
| 96 | }\r |
| 97 | \r |
| 98 | static int CheckIdle()\r |
| 99 | {\r |
| 100 | unsigned char state[0x88];\r |
| 101 | \r |
| 102 | memset(state,0,sizeof(state));\r |
| 103 | \r |
| 104 | // See if the state is the same after 2 steps:\r |
| 105 | SekState(state); SekRun(0); SekRun(0); SekState(state+0x44);\r |
| 106 | if (memcmp(state,state+0x44,0x44)==0) return 1;\r |
| 107 | \r |
| 108 | return 0;\r |
| 109 | }\r |
| 110 | \r |
| 111 | // Accurate but slower frame which does hints\r |
| 112 | static int PicoFrameHints()\r |
| 113 | {\r |
| 114 | struct PicoVideo *pv=&Pico.video;\r |
| 115 | int total=0,aim=0;\r |
| 116 | int y=0;\r |
| 117 | int hint=0x400; // Hint counter\r |
| 118 | \r |
| 119 | pv->status|=0x08; // Go into vblank\r |
| 120 | \r |
| 121 | for (y=-38;y<224;y++)\r |
| 122 | {\r |
| 123 | if (y==0)\r |
| 124 | {\r |
| 125 | hint=pv->reg[10]; // Load H-Int counter\r |
| 126 | if (pv->reg[1]&0x40) pv->status&=~8; // Come out of vblank if display enabled\r |
| 127 | }\r |
| 128 | \r |
| 129 | // H-Interrupts:\r |
| 130 | if (hint<0)\r |
| 131 | {\r |
| 132 | hint=pv->reg[10]; // Reload H-Int counter\r |
| 133 | if (pv->reg[0]&0x10) SekInterrupt(4);\r |
| 134 | }\r |
| 135 | \r |
| 136 | // V-Interrupt:\r |
| 137 | if (y==-37)\r |
| 138 | {\r |
| 139 | pv->status|=0x80; // V-Int happened\r |
| 140 | if (pv->reg[1]&0x20) SekInterrupt(6);\r |
| 141 | }\r |
| 142 | \r |
| 143 | Pico.m.scanline=(short)y;\r |
| 144 | \r |
| 145 | // Run scanline:\r |
| 146 | aim+=489; total+=SekRun(aim-total);\r |
| 147 | \r |
| 148 | hint--;\r |
| 149 | \r |
| 150 | if (PicoScan && y>=0) PicoLine(y);\r |
| 151 | }\r |
| 152 | \r |
| 153 | SekInterrupt(0); // Cancel interrupt\r |
| 154 | \r |
| 155 | return 0;\r |
| 156 | }\r |
| 157 | \r |
| 158 | // Simple frame without H-Ints\r |
| 159 | static int PicoFrameSimple()\r |
| 160 | {\r |
| 161 | int total=0,y=0,aim=0;\r |
| 162 | \r |
| 163 | Pico.m.scanline=-64;\r |
| 164 | \r |
| 165 | // V-Blanking period:\r |
| 166 | if (Pico.video.reg[1]&0x20) SekInterrupt(6); // Set IRQ\r |
| 167 | Pico.video.status|=0x88; // V-Int happened / go into vblank\r |
| 168 | total+=SekRun(18560);\r |
| 169 | \r |
| 170 | // Active Scan:\r |
| 171 | if (Pico.video.reg[1]&0x40) Pico.video.status&=~8; // Come out of vblank if display is enabled\r |
| 172 | SekInterrupt(0); // Clear IRQ\r |
| 173 | \r |
| 174 | // Run in sections:\r |
| 175 | for (aim=18560+6839; aim<=18560+6839*16; aim+=6839)\r |
| 176 | {\r |
| 177 | int add=0;\r |
| 178 | if (CheckIdle()) break;\r |
| 179 | add=SekRun(aim-total);\r |
| 180 | total+=add;\r |
| 181 | }\r |
| 182 | \r |
| 183 | if (PicoMask&0x100)\r |
| 184 | if (PicoScan)\r |
| 185 | {\r |
| 186 | // Draw the screen\r |
| 187 | for (y=0;y<224;y++) PicoLine(y);\r |
| 188 | }\r |
| 189 | \r |
| 190 | return 0;\r |
| 191 | }\r |
| 192 | \r |
| 193 | int PicoFrame()\r |
| 194 | {\r |
| 195 | int hints=0;\r |
| 196 | \r |
| 197 | if (Pico.rom==NULL) return 1; // No Rom plugged in\r |
| 198 | \r |
| 199 | \r |
| 200 | PmovUpdate();\r |
| 201 | \r |
| 202 | hints=Pico.video.reg[0]&0x10;\r |
| 203 | \r |
| 204 | if (hints) PicoFrameHints();\r |
| 205 | else PicoFrameSimple();\r |
| 206 | \r |
| 207 | PsndRender();\r |
| 208 | \r |
| 209 | return 0;\r |
| 210 | }\r |
| 211 | \r |
| 212 | static int DefaultCram(int cram)\r |
| 213 | {\r |
| 214 | int high=0x0841;\r |
| 215 | // Convert 0000bbbb ggggrrrr\r |
| 216 | // to rrrr1ggg g10bbbb1\r |
| 217 | high|=(cram&0x00f)<<12; // Red\r |
| 218 | high|=(cram&0x0f0)<< 3; // Green\r |
| 219 | high|=(cram&0xf00)>> 7; // Blue\r |
| 220 | return high;\r |
| 221 | }\r |
| 222 | \r |
| 223 | // Function to convert Megadrive Cram into a native colour:\r |
| 224 | int (*PicoCram)(int cram)=DefaultCram;\r |