[Core/CD] fixed CDD seeking start delay (fixes Radical Rex incorrect PRG-RAM & Word-RAM initialization, causing missing sprites during intro)

HISTORY.txt

@@ -58,9 +58,10 @@ Genesis Plus GX 1.7.5 (xx/xx/xxxx) (Eke-Eke)
 * fixed byte access to font data registers
 * fixed memory mode register bits masking when read from MAIN-CPU and SUB-CPU (verified on real hardware, cf. Krikzz's mcd-verificator)
 * fixed pending level 1 interrupts when GFX interrupt is disabled (fixes random freezes when exiting "Batman Returns" option menu)
-* fixed CDD seek command again (Final Fight CD freeze with model 2 BIOS)
+* fixed CDD seek command again (fixes Final Fight CD freeze with model 2 BIOS)
 * fixed CDD status reported during seek/access time (fixes sound effect synchronization issue in Bari Arm)
 * fixed CDD position reset when disc is stopped (fixes random freezes in Spiderman vs Kingpin when switching between audio tracks)
+* fixed CDD seeking start delay (fixes Radical Rex incorrect PRG-RAM & Word-RAM initialization, causing missing sprites during intro) */
 * fixed word access to CDD control register (fixes spurious audio track playback on startup with Mode 1 patched games using MSU-MD driver)
 * fixed CD communication registers state on peripheral reset (fixes SUB-CPU side initialization in MSU-MD sample demo and some Mode 1 patched games using MSU-MD driver)
 * fixed 32x32 pixels stamp index masking during GFX operation (fixes graphics rotation/scaling effects in "Chuck Rock II - Son of Chuck")

core/cd_hw/cdd.c

@@ -1893,6 +1893,79 @@ void cdd_update(void)
     /* udpate current track index */
     cdd.index = index;
   }
+
+  /* seeking should start with at least one interrupt delay (fixes Radical Rex incorrect PRG-RAM & Word-RAM initialization, causing missing sprites during intro) */
+  if (scd.regs[0x38>>1].byte.h == CD_SEEK)
+  {
+    /* reset track index */
+    int index = 0;
+
+    /* new LBA position */
+    int lba = ((scd.regs[0x44>>1].byte.h * 10 + scd.regs[0x44>>1].byte.l) * 60 + 
+               (scd.regs[0x46>>1].byte.h * 10 + scd.regs[0x46>>1].byte.l)) * 75 +
+               (scd.regs[0x48>>1].byte.h * 10 + scd.regs[0x48>>1].byte.l) - 150;
+
+    /* CD drive latency */
+    if (!cdd.latency)
+    {
+      /* Fixes a few games hanging because they expect data to be read with some delay */
+      /* Wolf Team games (Annet Futatabi, Aisle Lord, Cobra Command, Earnest Evans, Road Avenger & Time Gal) need at least 11 interrupts delay  */
+      /* Space Adventure Cobra (2nd morgue scene) needs at least 13 interrupts delay (incl. seek time, so 11 is OK) */
+      /* By default, at least two interrupts latency is required by current emulation model (BIOS hangs otherwise) */
+      cdd.latency = 2 + 9*config.cd_latency;
+    }
+
+    /* CD drive seek time */
+    /* max. seek time = 1.5 s = 1.5 x 75 = 112.5 CDD interrupts (rounded to 120) for 270000 sectors max on disc. */
+    /* Note: This is only a rough approximation since, on real hardware, seek time is much likely not linear and */
+    /* latency much larger than above value, but this model works fine for Sonic CD (track 26 playback needs to  */
+    /* be enough delayed to start in sync with intro sequence, as compared with real hardware recording).        */
+    /* It also works fine for Switch/Panic! intro (at least 30 interrupts are needed while seeking from 00:05:63 */
+    /* to 24:03:19 in Switch or when seeking from 00:05:60 to 24:06:07 in Panic!). */
+    if (lba > cdd.lba)
+    {
+      cdd.latency += (((lba - cdd.lba) * 120 * config.cd_latency) / 270000);
+    }
+    else 
+    {
+      cdd.latency += (((cdd.lba - lba) * 120 * config.cd_latency) / 270000);
+    }
+
+    /* update current LBA */
+    cdd.lba = lba;
+
+    /* get track index */
+    while ((cdd.toc.tracks[index].end <= lba) && (index < cdd.toc.last))
+      index++;
+
+    /* audio track ? */
+    if (cdd.toc.tracks[index].type == TYPE_AUDIO)
+    {
+      /* stay within track limits when seeking files */
+      if (lba < cdd.toc.tracks[index].start) 
+      {
+        lba = cdd.toc.tracks[index].start;
+      }
+
+      /* seek to current track sector */
+      cdd_seek_audio(index, lba);
+    }
+
+    /* update current track index */
+    cdd.index = index;
+
+    /* seek to current subcode position */
+    if (cdd.toc.sub)
+    {
+      cdStreamSeek(cdd.toc.sub, lba * 96, SEEK_SET);
+    }
+
+    /* no audio track playing (yet) */
+    scd.regs[0x36>>1].byte.h = 0x01;
+
+    /* update CDD status to either PLAY or PAUSE depending on host command (will be reported to host once seeking has ended) */
+    cdd.status = scd.regs[0x42>>1].byte.h & 0x05;
+  }
 }
 
 void cdd_process(void)
@@ -2069,73 +2142,7 @@ void cdd_process(void)
 
     case 0x03:  /* Play */
     {
-      /* reset track index */
+      /* RS0 should indicate seeking until drive is ready (fixes audio delay in Bari Arm) */
-      int index = 0;
-
-      /* new LBA position */
-      int lba = ((scd.regs[0x44>>1].byte.h * 10 + scd.regs[0x44>>1].byte.l) * 60 + 
-                 (scd.regs[0x46>>1].byte.h * 10 + scd.regs[0x46>>1].byte.l)) * 75 +
-                 (scd.regs[0x48>>1].byte.h * 10 + scd.regs[0x48>>1].byte.l) - 150;
-
-      /* CD drive latency */
-      if (!cdd.latency)
-      {
-        /* Fixes a few games hanging because they expect data to be read with some delay */
-        /* Wolf Team games (Annet Futatabi, Aisle Lord, Cobra Command, Earnest Evans, Road Avenger & Time Gal) need at least 11 interrupts delay  */
-        /* Space Adventure Cobra (2nd morgue scene) needs at least 13 interrupts delay (incl. seek time, so 11 is OK) */
-        /* By default, at least two interrupts latency is required by current emulation model (BIOS hangs otherwise) */
-        cdd.latency = 2 + 9*config.cd_latency;
-      }
-
-      /* CD drive seek time */
-      /* max. seek time = 1.5 s = 1.5 x 75 = 112.5 CDD interrupts (rounded to 120) for 270000 sectors max on disc. */
-      /* Note: This is only a rough approximation since, on real hardware, seek time is much likely not linear and */
-      /* latency much larger than above value, but this model works fine for Sonic CD (track 26 playback needs to  */
-      /* be enough delayed to start in sync with intro sequence, as compared with real hardware recording).        */
-      if (lba > cdd.lba)
-      {
-        cdd.latency += (((lba - cdd.lba) * 120 * config.cd_latency) / 270000);
-      }
-      else 
-      {
-        cdd.latency += (((cdd.lba - lba) * 120 * config.cd_latency) / 270000);
-      }
-
-      /* update current LBA */
-      cdd.lba = lba;
-
-      /* get track index */
-      while ((cdd.toc.tracks[index].end <= lba) && (index < cdd.toc.last)) index++;
-
-      /* audio track ? */
-      if (cdd.toc.tracks[index].type == TYPE_AUDIO)
-      {
-        /* stay within track limits when seeking files */
-        if (lba < cdd.toc.tracks[index].start) 
-        {
-          lba = cdd.toc.tracks[index].start;
-        }
-
-        /* seek to current track sector */
-        cdd_seek_audio(index, lba);
-      }
-
-      /* update current track index */
-      cdd.index = index;
-
-      /* seek to current subcode position */
-      if (cdd.toc.sub)
-      {
-        cdStreamSeek(cdd.toc.sub, lba * 96, SEEK_SET);
-      }
-
-      /* no audio track playing (yet) */
-      scd.regs[0x36>>1].byte.h = 0x01;
-
-      /* update status (reported to host once seeking has ended) */
-      cdd.status = CD_PLAY;
-
-      /* RS0 should indicates seeking until drive is ready (fixes audio delay in Bari Arm) */
       /* RS1=0xf to invalidate track infos in RS2-RS8 until drive is ready (fixes Snatcher Act 2 start cutscene) */
       scd.regs[0x38>>1].w = (CD_SEEK << 8) | 0x0f;
       scd.regs[0x3a>>1].w = 0x0000;
@@ -2147,61 +2154,6 @@ void cdd_process(void)
 
     case 0x04:  /* Seek */
     {
-      /* reset track index */
-      int index = 0;
-
-      /* new LBA position */
-      int lba = ((scd.regs[0x44>>1].byte.h * 10 + scd.regs[0x44>>1].byte.l) * 60 + 
-                 (scd.regs[0x46>>1].byte.h * 10 + scd.regs[0x46>>1].byte.l)) * 75 +
-                 (scd.regs[0x48>>1].byte.h * 10 + scd.regs[0x48>>1].byte.l) - 150;
-
-      /* CD drive seek time  */
-      /* We are using similar linear model as above, although still not exactly accurate, */
-      /* it works fine for Switch/Panic! intro (Switch needs at least 30 interrupts while */
-      /* seeking from 00:05:63 to 24:03:19, Panic! when seeking from 00:05:60 to 24:06:07) */
-      if (lba > cdd.lba)
-      {
-        cdd.latency = ((lba - cdd.lba) * 120 * config.cd_latency) / 270000;
-      }
-      else
-      {
-        cdd.latency = ((cdd.lba - lba) * 120 * config.cd_latency) / 270000;
-      }
-
-      /* update current LBA */
-      cdd.lba = lba;
-
-      /* get current track index */
-      while ((cdd.toc.tracks[index].end <= lba) && (index < cdd.toc.last)) index++;
-
-      /* audio track ? */
-      if (cdd.toc.tracks[index].type == TYPE_AUDIO)
-      {
-        /* stay within track limits when seeking files */
-        if (lba < cdd.toc.tracks[index].start) 
-        {
-          lba = cdd.toc.tracks[index].start;
-        }
-
-        /* seek to current track sector */
-        cdd_seek_audio(index, lba);
-      }
-
-      /* update current track index */
-      cdd.index = index;
-
-      /* seek to current subcode position */
-      if (cdd.toc.sub)
-      {
-        cdStreamSeek(cdd.toc.sub, lba * 96, SEEK_SET);
-      }
-
-      /* no audio track playing */
-      scd.regs[0x36>>1].byte.h = 0x01;
-
-      /* update status (reported to host once seeking has ended) */
-      cdd.status = CD_PAUSE;
-
       /* RS1=0xf to invalidate track infos in RS2-RS8 while seeking (fixes Final Fight CD intro when seek time is emulated) */
       scd.regs[0x38>>1].w = (CD_SEEK << 8) | 0x0f;
       scd.regs[0x3a>>1].w = 0x0000;