1 /* common code for Memory.c and cd/Memory.c */
3 static int PadRead(int i)
6 pad=~PicoPad[i]; // Get inverse of pad MXYZ SACB RLDU
7 TH=Pico.ioports[i+1]&0x40;
9 if(PicoOpt & 0x20) { // 6 button gamepad enabled
10 int phase = Pico.m.padTHPhase[i];
12 if(phase == 2 && !TH) {
13 value=(pad&0xc0)>>2; // ?0SA 0000
15 } else if(phase == 3 && TH) {
16 value=(pad&0x30)|((pad>>8)&0xf); // ?1CB MXYZ
18 } else if(phase == 3 && !TH) {
19 value=((pad&0xc0)>>2)|0x0f; // ?0SA 1111
24 if(TH) value=(pad&0x3f); // ?1CB RLDU
25 else value=((pad&0xc0)>>2)|(pad&3); // ?0SA 00DU
29 // orr the bits, which are set as output
30 value |= Pico.ioports[i+1]&Pico.ioports[i+4];
32 return value; // will mirror later
41 if(Pico.m.z80Run&1) return 0;
46 // Z80 disabled, do some faking
47 static u8 zerosent = 0;
48 if(a == Pico.m.z80_lastaddr) { // probably polling something
49 u8 d = Pico.m.z80_fakeval;
50 if((d & 0xf) == 0xf && !zerosent) {
58 Pico.m.z80_fakeval = 0;
62 Pico.m.z80_lastaddr = (u16) a;
70 u32 OtherRead16(u32 a, int realsize)
74 if ((a&0xff0000)==0xa00000) {
75 if ((a&0x4000)==0x0000) { d=z80Read8(a); d|=d<<8; goto end; } // Z80 ram (not byteswaped)
76 if ((a&0x6000)==0x4000) { // 0x4000-0x5fff, Fudge if disabled
77 if(PicoOpt&1) d=YM2612Read();
78 else d=Pico.m.rotate++&3;
79 dprintf("read ym2612: %04x", d);
86 if ((a&0xffffe0)==0xa10000) { // I/O ports
89 case 0: d=Pico.m.hardware; break; // Hardware value (Version register)
90 case 1: d=PadRead(0); d|=Pico.ioports[1]&0x80; break;
91 case 2: d=PadRead(1); d|=Pico.ioports[2]&0x80; break;
92 default: d=Pico.ioports[a]; break; // IO ports can be used as RAM
98 // |=0x80 for Shadow of the Beast & Super Offroad; rotate fakes next fetched instruction for Time Killers
99 if (a==0xa11100) { // z80 busreq
102 // needed by buggy Terminator (Sega CD)
103 extern int z80stopCycle;
104 int stop_before = SekCyclesDone() - z80stopCycle;
105 dprintf("stop before: %i", stop_before);
106 if (stop_before > 0 && stop_before <= 32) // Gens uses 16 here
107 d = 1; // bus not yet available
109 d=(d<<8)|0x8000|Pico.m.rotate++;
110 dprintf("get_zrun: %04x [%i|%i] @%06x", d, Pico.m.scanline, SekCyclesDone(), SekPc);
114 #ifndef _ASM_MEMORY_C
115 if ((a&0xe700e0)==0xc00000) { d=PicoVideoRead(a); goto end; }
118 d = OtherRead16End(a, realsize);
125 //extern UINT32 mz80GetRegisterValue(void *, UINT32);
127 static void OtherWrite8(u32 a,u32 d,int realsize)
129 if ((a&0xe700f9)==0xc00011||(a&0xff7ff9)==0xa07f11) { if(PicoOpt&2) SN76496Write(d); return; } // PSG Sound
130 if ((a&0xff4000)==0xa00000) { if(!(Pico.m.z80Run&1)) Pico.zram[a&0x1fff]=(u8)d; return; } // Z80 ram
131 if ((a&0xff6000)==0xa04000) { if(PicoOpt&1) emustatus|=YM2612Write(a&3, d); return; } // FM Sound
132 if ((a&0xffffe0)==0xa10000) { // I/O ports
134 // 6 button gamepad: if TH went from 0 to 1, gamepad changes state
137 Pico.m.padDelay[0] = 0;
138 if(!(Pico.ioports[1]&0x40) && (d&0x40)) Pico.m.padTHPhase[0]++;
141 Pico.m.padDelay[1] = 0;
142 if(!(Pico.ioports[2]&0x40) && (d&0x40)) Pico.m.padTHPhase[1]++;
145 Pico.ioports[a]=(u8)d; // IO ports can be used as RAM
149 extern int z80startCycle, z80stopCycle;
150 //int lineCycles=(488-SekCyclesLeft)&0x1ff;
153 // this is for a nasty situation where Z80 was enabled and disabled in the same 68k timeslice (Golden Axe III)
155 int lineCycles=(488-SekCyclesLeft)&0x1ff;
156 z80stopCycle = SekCyclesDone();
157 lineCycles=(lineCycles>>1)-(lineCycles>>5);
161 z80startCycle = SekCyclesDone();
162 //if(Pico.m.scanline != -1)
164 dprintf("set_zrun: %02x [%i|%i] @%06x", d, Pico.m.scanline, SekCyclesDone(), /*mz80GetRegisterValue(NULL, 0),*/ SekPc);
165 Pico.m.z80Run=(u8)d; return;
168 dprintf("write z80Reset: %02x", d);
169 if(!(d&1)) z80_reset();
173 if ((a&0xff7f00)==0xa06000) // Z80 BANK register
175 Pico.m.z80_bank68k>>=1;
176 Pico.m.z80_bank68k|=(d&1)<<8;
177 Pico.m.z80_bank68k&=0x1ff; // 9 bits and filled in the new top one
181 if ((a&0xe700e0)==0xc00000) {
182 PicoVideoWrite(a,(u16)(d|(d<<8))); // Byte access gets mirrored
186 OtherWrite8End(a, d, realsize);
190 static void OtherWrite16(u32 a,u32 d)
192 if ((a&0xe700e0)==0xc00000) { PicoVideoWrite(a,(u16)d); return; }
193 if ((a&0xff4000)==0xa00000) { if(!(Pico.m.z80Run&1)) Pico.zram[a&0x1fff]=(u8)(d>>8); return; } // Z80 ram (MSB only)
195 if ((a&0xffffe0)==0xa10000) { // I/O ports
197 // 6 button gamepad: if TH went from 0 to 1, gamepad changes state
200 Pico.m.padDelay[0] = 0;
201 if(!(Pico.ioports[1]&0x40) && (d&0x40)) Pico.m.padTHPhase[0]++;
204 Pico.m.padDelay[1] = 0;
205 if(!(Pico.ioports[2]&0x40) && (d&0x40)) Pico.m.padTHPhase[1]++;
208 Pico.ioports[a]=(u8)d; // IO ports can be used as RAM
211 if (a==0xa11100) { OtherWrite8(a, d>>8, 16); return; }
212 if (a==0xa11200) { dprintf("write z80reset: %04x", d); if(!(d&0x100)) z80_reset(); return; }
214 OtherWrite8(a, d>>8, 16);
215 OtherWrite8(a+1,d&0xff, 16);