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1 | \r |
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2 | // This file is part of the PicoDrive Megadrive Emulator\r |
3 | \r |
c41b9b97 |
4 | // Copyright (c) 2011 FinalDave (emudave (at) gmail.com)\r |
5 | \r |
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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 |
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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 |