+/* common code for Memory.c and cd/Memory.c */
+
+static int PadRead(int i)
+{
+ int pad=0,value=0,TH;
+ pad=~PicoPad[i]; // Get inverse of pad MXYZ SACB RLDU
+ TH=Pico.ioports[i+1]&0x40;
+
+ if(PicoOpt & 0x20) { // 6 button gamepad enabled
+ int phase = Pico.m.padTHPhase[i];
+
+ if(phase == 2 && !TH) {
+ value=(pad&0xc0)>>2; // ?0SA 0000
+ goto end;
+ } else if(phase == 3 && TH) {
+ value=(pad&0x30)|((pad>>8)&0xf); // ?1CB MXYZ
+ goto end;
+ } else if(phase == 3 && !TH) {
+ value=((pad&0xc0)>>2)|0x0f; // ?0SA 1111
+ goto end;
+ }
+ }
+
+ if(TH) value=(pad&0x3f); // ?1CB RLDU
+ else value=((pad&0xc0)>>2)|(pad&3); // ?0SA 00DU
+
+ end:
+
+ // orr the bits, which are set as output
+ value |= Pico.ioports[i+1]&Pico.ioports[i+4];
+
+ return value; // will mirror later
+}
+
+
+#ifndef _ASM_MEMORY_C
+static
+#endif
+u8 z80Read8(u32 a)
+{
+ if(Pico.m.z80Run&1) return 0;
+
+ a&=0x1fff;
+
+ if(!(PicoOpt&4)) {
+ // Z80 disabled, do some faking
+ static u8 zerosent = 0;
+ if(a == Pico.m.z80_lastaddr) { // probably polling something
+ u8 d = Pico.m.z80_fakeval;
+ if((d & 0xf) == 0xf && !zerosent) {
+ d = 0; zerosent = 1;
+ } else {
+ Pico.m.z80_fakeval++;
+ zerosent = 0;
+ }
+ return d;
+ } else {
+ Pico.m.z80_fakeval = 0;
+ }
+ }
+
+ Pico.m.z80_lastaddr = (u16) a;
+ return Pico.zram[a];
+}
+
+
+#ifndef _ASM_MEMORY_C
+static
+#endif
+u32 OtherRead16(u32 a, int realsize)
+{
+ u32 d=0;
+
+ if ((a&0xff0000)==0xa00000) {
+ if ((a&0x4000)==0x0000) { d=z80Read8(a); d|=d<<8; goto end; } // Z80 ram (not byteswaped)
+ if ((a&0x6000)==0x4000) { // 0x4000-0x5fff, Fudge if disabled
+ if(PicoOpt&1) d=YM2612Read();
+ else d=Pico.m.rotate++&3;
+ dprintf("read ym2612: %04x", d);
+ goto end;
+ }
+ d=0xffff;
+ goto end;
+ }
+
+ if ((a&0xffffe0)==0xa10000) { // I/O ports
+ a=(a>>1)&0xf;
+ switch(a) {
+ case 0: d=Pico.m.hardware; break; // Hardware value (Version register)
+ case 1: d=PadRead(0); d|=Pico.ioports[1]&0x80; break;
+ case 2: d=PadRead(1); d|=Pico.ioports[2]&0x80; break;
+ default: d=Pico.ioports[a]; break; // IO ports can be used as RAM
+ }
+ d|=d<<8;
+ goto end;
+ }
+
+ // |=0x80 for Shadow of the Beast & Super Offroad; rotate fakes next fetched instruction for Time Killers
+ if (a==0xa11100) { // z80 busreq
+ d=Pico.m.z80Run&1;
+#if 0
+ if (!d) {
+ // do we need this?
+ extern int z80stopCycle;
+ int stop_before = SekCyclesDone() - z80stopCycle;
+ if (stop_before > 0 && stop_before <= 16) // Gens uses 16 here
+ d = 1; // bus not yet available
+ }
+#endif
+ d=(d<<8)|0x8000|Pico.m.rotate++;
+ dprintf("get_zrun: %04x [%i|%i] @%06x", d, Pico.m.scanline, SekCyclesDone(), SekPc);
+ goto end;
+ }
+
+#ifndef _ASM_MEMORY_C
+ if ((a&0xe700e0)==0xc00000) { d=PicoVideoRead(a); goto end; }
+#endif
+
+ d = OtherRead16End(a, realsize);
+
+end:
+ return d;
+}
+
+
+//extern UINT32 mz80GetRegisterValue(void *, UINT32);
+
+static void OtherWrite8(u32 a,u32 d,int realsize)
+{
+ if ((a&0xe700f9)==0xc00011||(a&0xff7ff9)==0xa07f11) { if(PicoOpt&2) SN76496Write(d); return; } // PSG Sound
+ if ((a&0xff4000)==0xa00000) { if(!(Pico.m.z80Run&1)) Pico.zram[a&0x1fff]=(u8)d; return; } // Z80 ram
+ if ((a&0xff6000)==0xa04000) { if(PicoOpt&1) emustatus|=YM2612Write(a&3, d); return; } // FM Sound
+ if ((a&0xffffe0)==0xa10000) { // I/O ports
+ a=(a>>1)&0xf;
+ // 6 button gamepad: if TH went from 0 to 1, gamepad changes state
+ if(PicoOpt&0x20) {
+ if(a==1) {
+ Pico.m.padDelay[0] = 0;
+ if(!(Pico.ioports[1]&0x40) && (d&0x40)) Pico.m.padTHPhase[0]++;
+ }
+ else if(a==2) {
+ Pico.m.padDelay[1] = 0;
+ if(!(Pico.ioports[2]&0x40) && (d&0x40)) Pico.m.padTHPhase[1]++;
+ }
+ }
+ Pico.ioports[a]=(u8)d; // IO ports can be used as RAM
+ return;
+ }
+ if (a==0xa11100) {
+ extern int z80startCycle, z80stopCycle;
+ //int lineCycles=(488-SekCyclesLeft)&0x1ff;
+ d&=1; d^=1;
+ if(!d) {
+ // this is for a nasty situation where Z80 was enabled and disabled in the same 68k timeslice (Golden Axe III)
+ if (Pico.m.z80Run) {
+ int lineCycles=(488-SekCyclesLeft)&0x1ff;
+ z80stopCycle = SekCyclesDone();
+ lineCycles=(lineCycles>>1)-(lineCycles>>5);
+ z80_run(lineCycles);
+ }
+ } else {
+ z80startCycle = SekCyclesDone();
+ //if(Pico.m.scanline != -1)
+ }
+ dprintf("set_zrun: %02x [%i|%i] @%06x", d, Pico.m.scanline, SekCyclesDone(), /*mz80GetRegisterValue(NULL, 0),*/ SekPc);
+ Pico.m.z80Run=(u8)d; return;
+ }
+ if (a==0xa11200) {
+ dprintf("write z80Reset: %02x", d);
+ if(!(d&1)) z80_reset();
+ return;
+ }
+
+ if ((a&0xff7f00)==0xa06000) // Z80 BANK register
+ {
+ Pico.m.z80_bank68k>>=1;
+ Pico.m.z80_bank68k|=(d&1)<<8;
+ Pico.m.z80_bank68k&=0x1ff; // 9 bits and filled in the new top one
+ return;
+ }
+
+ if ((a&0xe700e0)==0xc00000) {
+ PicoVideoWrite(a,(u16)(d|(d<<8))); // Byte access gets mirrored
+ return;
+ }
+
+ OtherWrite8End(a, d, realsize);
+}
+
+
+static void OtherWrite16(u32 a,u32 d)
+{
+ if ((a&0xe700e0)==0xc00000) { PicoVideoWrite(a,(u16)d); return; }
+ if ((a&0xff4000)==0xa00000) { if(!(Pico.m.z80Run&1)) Pico.zram[a&0x1fff]=(u8)(d>>8); return; } // Z80 ram (MSB only)
+
+ if ((a&0xffffe0)==0xa10000) { // I/O ports
+ a=(a>>1)&0xf;
+ // 6 button gamepad: if TH went from 0 to 1, gamepad changes state
+ if(PicoOpt&0x20) {
+ if(a==1) {
+ Pico.m.padDelay[0] = 0;
+ if(!(Pico.ioports[1]&0x40) && (d&0x40)) Pico.m.padTHPhase[0]++;
+ }
+ else if(a==2) {
+ Pico.m.padDelay[1] = 0;
+ if(!(Pico.ioports[2]&0x40) && (d&0x40)) Pico.m.padTHPhase[1]++;
+ }
+ }
+ Pico.ioports[a]=(u8)d; // IO ports can be used as RAM
+ return;
+ }
+ if (a==0xa11100) { OtherWrite8(a, d>>8, 16); return; }
+ if (a==0xa11200) { dprintf("write z80reset: %04x", d); if(!(d&0x100)) z80_reset(); return; }
+
+ OtherWrite8(a, d>>8, 16);
+ OtherWrite8(a+1,d&0xff, 16);
+}
+
+