[Core/CD]

.added build-in TOC support for a few games that hang if no audio tracks are
found or used
.modified CD access/seek time emulation
.improved CPU polling detection
.improved SUB & MAIN-CPU synchronization (fixes Dracula Unleashed when using
Model 2 US BIOS)
.added missing reinitialization of MAIN-CPU PRG-RAM bank on reset

source/cd_hw/cdd.c

@@ -90,6 +90,26 @@ static const uint32 toc_shadow[15] =
   11637,  2547,  2521,  3856, 900
 };
 
+static const uint32 toc_dungeon[13] =
+{
+  2250, 22950, 16350, 24900, 13875, 19950, 13800, 15375, 17400, 17100,
+  3325,  6825, 25275
+};
+
+static const uint32 toc_ffight[26] =
+{
+  11994, 9742, 10136, 9685, 9553, 14588, 9430, 8721, 9975, 9764,
+  9704, 12796, 585, 754, 951, 624, 9047, 1068, 817, 9191, 1024,
+  14562, 10320, 8627, 3795, 3047
+};
+
+static const uint32 toc_ffightj[29] =
+{
+  11994, 9752, 10119, 9690, 9567, 14575, 9431, 8731, 9965, 9763,
+  9716, 12791, 579, 751, 958, 630, 9050, 1052, 825, 9193, 1026,
+  14553, 9834, 10542, 1699, 1792, 1781, 3783, 3052
+};
+
 /* supported WAVE file header (16-bit stereo samples @44.1kHz) */
 static const unsigned char waveHeader[32] =
 {
@@ -641,6 +661,45 @@ int cdd_load(char *filename, char *header)
       }
       while (cdd.toc.last < 15);
     }
+    else if (strstr(header + 0x180,"T-143025") != NULL)
+    {
+      /* Dungeon Explorer */
+      cdd.toc.last = cdd.toc.end = 0;
+      do
+      {
+        cdd.toc.tracks[cdd.toc.last].start = cdd.toc.end;
+        cdd.toc.tracks[cdd.toc.last].end = cdd.toc.tracks[cdd.toc.last].start + toc_dungeon[cdd.toc.last];
+        cdd.toc.end = cdd.toc.tracks[cdd.toc.last].end;
+        cdd.toc.last++;
+      }
+      while (cdd.toc.last < 13);
+    }
+    else if (strstr(header + 0x180,"MK-4410") != NULL)
+    {
+      /* Final Fight CD (USA, Europe) */
+      cdd.toc.last = cdd.toc.end = 0;
+      do
+      {
+        cdd.toc.tracks[cdd.toc.last].start = cdd.toc.end;
+        cdd.toc.tracks[cdd.toc.last].end = cdd.toc.tracks[cdd.toc.last].start + toc_ffight[cdd.toc.last];
+        cdd.toc.end = cdd.toc.tracks[cdd.toc.last].end;
+        cdd.toc.last++;
+      }
+      while (cdd.toc.last < 26);
+    }
+    else if (strstr(header + 0x180,"G-6013") != NULL)
+    {
+      /* Final Fight CD (Japan) */
+      cdd.toc.last = cdd.toc.end = 0;
+      do
+      {
+        cdd.toc.tracks[cdd.toc.last].start = cdd.toc.end;
+        cdd.toc.tracks[cdd.toc.last].end = cdd.toc.tracks[cdd.toc.last].start + toc_ffightj[cdd.toc.last];
+        cdd.toc.end = cdd.toc.tracks[cdd.toc.last].end;
+        cdd.toc.last++;
+      }
+      while (cdd.toc.last < 29);
+    }
     else
     {
       /* default TOC (99 tracks & 2s per audio tracks) */
@@ -1081,11 +1140,24 @@ void cdd_process(void)
       if (!cdd.latency)
       {
         /* Fixes a few games hanging during intro because they expect data to be read with some delay */
-        /* Wolf Team games (Anet Futatabi, Cobra Command, Road Avenger & Time Gal) need at least 6 interrupts delay */
         /* Radical Rex needs at least one interrupt delay */
-        /* Jeopardy needs at least 9 interrupts delay */
+        /* Wolf Team games (Anet Futatabi, Cobra Command, Road Avenger & Time Gal) need at least 6 interrupts delay */
-        /* Space Adventure Cobra (2nd morgue scene) needs at least 13 interrupts delay */
+        /* Space Adventure Cobra (2nd morgue scene) needs at least 13 interrupts delay (incl. seek time, so 6 here is OK) */
-        cdd.latency = 13;
+        /* Jeopardy & ESPN Sunday Night NFL are picky about this as well: 7 interrupts delay (+ seek time) seems OK */
+        cdd.latency = 7;
+      }
+
+      /* CD drive seek time */
+      /* Some delay is especially needed when playing audio tracks located at the end of the disc (ex: Sonic CD intro) */
+      /* max. seek time = 1.5s = 1.5 x 75 = 112.5 CDD interrupts (rounded to 120) for 270000 sectors max on disc */
+      /* Note: this is only a rough approximation, on real hardware, drive seek time is much likely not linear */
+      if (lba < cdd.lba)
+      {
+        cdd.latency += (((cdd.lba - lba) * 120) / 270000);
+      }
+      else 
+      {
+        cdd.latency += (((lba - cdd.lba) * 120) / 270000);
       }
 
       /* update current track index */
@@ -1110,19 +1182,6 @@ void cdd_process(void)
       }
       else if (cdd.toc.tracks[index].fd)
       {
-        /* CD drive seek time */
-        /* Some delay is also needed when playing AUDIO tracks located at the end of the disc (ex: Sonic CD intro) */
-        /* max. seek time = 1.5s = 1.5 x 75 = 112.5 CDD interrupts (rounded to 120) for 270000 sectors max on disc */
-        /* Note: this is only a rough approximation, on real hardware, drive seek time is much likely not linear */
-        if (lba < cdd.lba)
-        {
-          cdd.latency += (((cdd.lba - lba) * 120) / 270000);
-        }
-        else 
-        {
-          cdd.latency += (((lba - cdd.lba) * 120) / 270000);
-        }
-
         /* seek AUDIO track */
         if (lba < cdd.toc.tracks[index].start)
         {

source/cd_hw/scd.c

@@ -212,7 +212,7 @@ static void s68k_poll_detect(reg)
   }
 
   /* restart SUB-CPU polling detection */
-  s68k.poll.cycle = s68k.cycles + 320;
+  s68k.poll.cycle = s68k.cycles + 392;
   s68k.poll.pc = s68k.pc;
 }
 
@@ -412,7 +412,7 @@ static unsigned int scd_read_word(unsigned int address)
     /* relative MAIN-CPU cycle counter */
     unsigned int cycles = (s68k.cycles * MCYCLES_PER_LINE) / SCYCLES_PER_LINE;
 
-    /* sync MAIN-CPU with SUB-CPU */
+    /* sync MAIN-CPU with SUB-CPU (Mighty Morphin Power Rangers) */
     if (!m68k.stopped && (m68k.cycles < cycles))
     {
       m68k_run(cycles);
@@ -1062,7 +1062,7 @@ void scd_init(void)
   {
     if (i & 2)
     {
-      /* PRG-RAM (first 128KB bank, mirrored) */
+      /* $020000-$03FFFF (resp. $420000-$43FFFF): PRG-RAM (first 128KB bank, mirrored each 256KB) */
       m68k.memory_map[i].base    = scd.prg_ram + ((i & 1) << 16);
       m68k.memory_map[i].read8   = NULL;
       m68k.memory_map[i].read16  = NULL;
@@ -1074,7 +1074,8 @@ void scd_init(void)
     }
     else
     {
-      /* internal ROM (128KB mirrored) (Flux expects it to be mapped at $440000-$45FFFF) */
+      /* $000000-$01FFFF (resp. $400000-$41FFFF): internal ROM (128KB, mirrored each 256KB) */
+      /* NB: Flux expects it to be mapped at $440000-$45FFFF */
       m68k.memory_map[i].base    = scd.bootrom + ((i & 1) << 16);
       m68k.memory_map[i].read8   = NULL;
       m68k.memory_map[i].read16  = NULL;
@@ -1116,7 +1117,6 @@ void scd_init(void)
   /* $080000-$0BFFFF:  Word-RAM in 2M mode (256KB)*/
   for (i=0x08; i<0x0c; i++)
   {
-    /* allow Word-RAM access from both CPU in 2M mode (fixes sync issues in Mortal Kombat) */
     s68k.memory_map[i].base    = scd.word_ram_2M + ((i & 3) << 16);
     s68k.memory_map[i].read8   = NULL;
     s68k.memory_map[i].read16  = NULL;
@@ -1167,6 +1167,8 @@ void scd_reset(int hard)
   /* TODO: figure what exactly is resetted when RESET bit is cleared by SUB-CPU */
   if (hard)
   {
+    int i;
+    
     /* Clear all ASIC registers by default */
     memset(scd.regs, 0, sizeof(scd.regs));
 
@@ -1183,6 +1185,14 @@ void scd_reset(int hard)
 
     /* 2M mode */
     word_ram_switch(0);
+
+    /* reset PRG-RAM banking on MAIN-CPU side */
+    for (i=scd.cartridge.boot+0x02; i<scd.cartridge.boot+0x20; i+=4)
+    {
+      /* MAIN-CPU: $020000-$03FFFF (resp. $420000-$43FFFF) mapped to first 128KB PRG-RAM bank (mirrored each 256KB) */
+      m68k.memory_map[i].base = scd.prg_ram;
+      m68k.memory_map[i+1].base = scd.prg_ram + 0x10000;
+    }
   }
   else
   {

source/mem68k.c

@@ -48,7 +48,7 @@ unsigned int m68k_read_bus_8(unsigned int address)
 #ifdef LOGERROR
   error("Unused read8 %08X (%08X)\n", address, m68k_get_reg(M68K_REG_PC));
 #endif
-  address =   m68k.pc | (address & 1);
+  address = m68k.pc | (address & 1);
   return READ_BYTE(m68k.memory_map[((address)>>16)&0xff].base, (address) & 0xffff);
 }
 
@@ -238,6 +238,13 @@ static void m68k_poll_detect(reg)
 #endif
         m68k.cycles = m68k.cycle_end;
         m68k.stopped = 1 << reg;
+
+        /* return to current instruction */
+        do
+        {
+          m68k.pc -= 2;
+        }
+        while (m68k.ir != *(uint16 *)(m68k.memory_map[(m68k.pc>>16)&0xff].base + (m68k.pc & 0xffff)));
       }
       return;
     }
@@ -249,7 +256,7 @@ static void m68k_poll_detect(reg)
   }
 
   /* restart MAIN-CPU polling detection */
-  m68k.poll.cycle = m68k.cycles + 280;
+  m68k.poll.cycle = m68k.cycles + 840;
   m68k.poll.pc = m68k.pc;
 }
 
@@ -335,6 +342,15 @@ unsigned int ctrl_io_read_byte(unsigned int address)
         /* SUB-CPU communication flags */
         if (index == 0x0f)
         {
+          /* relative SUB-CPU cycle counter */
+          unsigned int cycles = (m68k.cycles * SCYCLES_PER_LINE) / MCYCLES_PER_LINE;
+
+          /* sync SUB-CPU with MAIN-CPU (Dracula Unleashed w/ Sega CD Model 2 OS ROM) */
+          if (!s68k.stopped && (s68k.cycles < cycles))
+          {
+            s68k_run(cycles);
+          }
+
           m68k_poll_detect(0x0f);
           return scd.regs[0x0f>>1].byte.l;
         }