psxbios: experimental vsync HLE
[pcsx_rearmed.git] / libpcsxcore / cdrom.c
index b3e238b..e232d05 100644 (file)
@@ -21,7 +21,9 @@
 * Handles all CD-ROM registers and functions.
 */
 
+#include <assert.h>
 #include "cdrom.h"
+#include "misc.h"
 #include "ppf.h"
 #include "psxdma.h"
 #include "arm_features.h"
@@ -35,7 +37,8 @@
 #if 0
 #define CDR_LOG_I SysPrintf
 #else
-#define CDR_LOG_I log_unhandled
+#define CDR_LOG_I(fmt, ...) \
+       log_unhandled("%u cdrom: " fmt, psxRegs.cycle, ##__VA_ARGS__)
 #endif
 #if 0
 #define CDR_LOG_IO SysPrintf
@@ -63,7 +66,8 @@ static struct {
                unsigned char Absolute[3];
        } subq;
        unsigned char TrackChanged;
-       unsigned char unused3[3];
+       unsigned char ReportDelay;
+       unsigned char unused3[2];
        unsigned int  freeze_ver;
 
        unsigned char Prev[4];
@@ -76,7 +80,7 @@ static struct {
        unsigned char ResultP;
        unsigned char ResultReady;
        unsigned char Cmd;
-       unsigned char unused4;
+       unsigned char SubqForwardSectors;
        unsigned char SetlocPending;
        u32 Reading;
 
@@ -100,14 +104,14 @@ static struct {
        u16 CmdInProgress;
        u8 Irq1Pending;
        u8 unused5;
-       u32 unused6;
+       u32 LastReadCycles;
 
        u8 unused7;
 
        u8 DriveState;
        u8 FastForward;
        u8 FastBackward;
-       u8 unused8;
+       u8 errorRetryhack;
 
        u8 AttenuatorLeftToLeft, AttenuatorLeftToRight;
        u8 AttenuatorRightToRight, AttenuatorRightToLeft;
@@ -208,6 +212,7 @@ unsigned char Test23[] = { 0x43, 0x58, 0x44, 0x32, 0x39 ,0x34, 0x30, 0x51 };
 #define cdReadTime (PSXCLK / 75)
 
 #define LOCL_INVALID 0xff
+#define SUBQ_FORWARD_SECTORS 2u
 
 enum drive_state {
        DRIVESTATE_STANDBY = 0, // pause, play, read
@@ -296,8 +301,8 @@ static void setIrq(int log_cmd)
        if (cdr.Stat)
        {
                int i;
-               SysPrintf("%u cdrom: CDR IRQ=%d cmd %02x stat %02x: ",
-                       psxRegs.cycle, !!(cdr.Stat & cdr.Reg2), log_cmd, cdr.Stat);
+               CDR_LOG_I("CDR IRQ=%d cmd %02x stat %02x: ",
+                       !!(cdr.Stat & cdr.Reg2), log_cmd, cdr.Stat);
                for (i = 0; i < cdr.ResultC; i++)
                        SysPrintf("%02x ", cdr.Result[i]);
                SysPrintf("\n");
@@ -309,7 +314,7 @@ static void setIrq(int log_cmd)
 // (yes it's slow, but you probably don't want to modify it)
 void cdrLidSeekInterrupt(void)
 {
-       CDR_LOG_I("%u %s cdr.DriveState=%d\n", psxRegs.cycle, __func__, cdr.DriveState);
+       CDR_LOG_I("%s cdr.DriveState=%d\n", __func__, cdr.DriveState);
 
        switch (cdr.DriveState) {
        default:
@@ -323,6 +328,7 @@ void cdrLidSeekInterrupt(void)
 
                if (stat.Status & STATUS_SHELLOPEN)
                {
+                       memset(cdr.Prev, 0xff, sizeof(cdr.Prev));
                        cdr.DriveState = DRIVESTATE_LID_OPEN;
                        CDRLID_INT(0x800);
                }
@@ -447,11 +453,10 @@ static void generate_subq(const u8 *time)
        cdr.subq.Absolute[2] = itob(time[2]);
 }
 
-static int ReadTrack(const u8 *time) {
+static int ReadTrack(const u8 *time)
+{
        unsigned char tmp[3];
-       struct SubQ *subq;
        int read_ok;
-       u16 crc;
 
        tmp[0] = itob(time[0]);
        tmp[1] = itob(time[1]);
@@ -463,12 +468,20 @@ static int ReadTrack(const u8 *time) {
        CDR_LOG("ReadTrack *** %02x:%02x:%02x\n", tmp[0], tmp[1], tmp[2]);
 
        read_ok = CDR_readTrack(tmp);
-       memcpy(cdr.Prev, tmp, 3);
+       if (read_ok)
+               memcpy(cdr.Prev, tmp, 3);
+       return read_ok;
+}
+
+static void UpdateSubq(const u8 *time)
+{
+       const struct SubQ *subq;
+       u16 crc;
 
        if (CheckSBI(time))
-               return read_ok;
+               return;
 
-       subq = (struct SubQ *)CDR_getBufferSub();
+       subq = (struct SubQ *)CDR_getBufferSub(MSF2SECT(time[0], time[1], time[2]));
        if (subq != NULL && cdr.CurTrack == 1) {
                crc = calcCrc((u8 *)subq + 12, 10);
                if (crc == (((u16)subq->CRC[0] << 8) | subq->CRC[1])) {
@@ -478,8 +491,8 @@ static int ReadTrack(const u8 *time) {
                        memcpy(cdr.subq.Absolute, subq->AbsoluteAddress, 3);
                }
                else {
-                       CDR_LOG_I("subq bad crc @%02x:%02x:%02x\n",
-                               tmp[0], tmp[1], tmp[2]);
+                       CDR_LOG_I("subq bad crc @%02d:%02d:%02d\n",
+                               time[0], time[1], time[2]);
                }
        }
        else {
@@ -490,8 +503,6 @@ static int ReadTrack(const u8 *time) {
                cdr.subq.Track, cdr.subq.Index,
                cdr.subq.Relative[0], cdr.subq.Relative[1], cdr.subq.Relative[2],
                cdr.subq.Absolute[0], cdr.subq.Absolute[1], cdr.subq.Absolute[2]);
-
-       return read_ok;
 }
 
 static void cdrPlayInterrupt_Autopause()
@@ -515,7 +526,9 @@ static void cdrPlayInterrupt_Autopause()
                StopCdda();
                SetPlaySeekRead(cdr.StatP, 0);
        }
-       else if (((cdr.Mode & MODE_REPORT) || cdr.FastForward || cdr.FastBackward)) {
+       else if ((cdr.Mode & MODE_REPORT) && !cdr.ReportDelay &&
+                ((cdr.subq.Absolute[2] & 0x0f) == 0 || cdr.FastForward || cdr.FastBackward))
+       {
                cdr.Result[0] = cdr.StatP;
                cdr.Result[1] = cdr.subq.Track;
                cdr.Result[2] = cdr.subq.Index;
@@ -551,39 +564,77 @@ static void cdrPlayInterrupt_Autopause()
                SetResultSize(8);
                setIrq(0x1001);
        }
+
+       if (cdr.ReportDelay)
+               cdr.ReportDelay--;
 }
 
+// LastReadCycles
 static int cdrSeekTime(unsigned char *target)
 {
        int diff = msf2sec(cdr.SetSectorPlay) - msf2sec(target);
-       int seekTime = abs(diff) * (cdReadTime / 200);
-       /*
-       * Gameblabla :
-       * It was originally set to 1000000 for Driver, however it is not high enough for Worms Pinball
-       * and was unreliable for that game.
-       * I also tested it against Mednafen and Driver's titlescreen music starts 25 frames later, not immediatly.
-       *
-       * Obviously, this isn't perfect but right now, it should be a bit better.
-       * Games to test this against if you change that setting :
-       * - Driver (titlescreen music delay and retry mission)
-       * - Worms Pinball (Will either not boot or crash in the memory card screen)
-       * - Viewpoint (short pauses if the delay in the ingame music is too long)
-       *
-       * It seems that 3386880 * 5 is too much for Driver's titlescreen and it starts skipping.
-       * However, 1000000 is not enough for Worms Pinball to reliably boot.
-       */
-       if(seekTime > 3386880 * 2) seekTime = 3386880 * 2;
+       int pausePenalty, seekTime = abs(diff) * (cdReadTime / 2000);
+       seekTime = MAX_VALUE(seekTime, 20000);
+
+       // need this stupidly long penalty or else Spyro2 intro desyncs
+       pausePenalty = (s32)(psxRegs.cycle - cdr.LastReadCycles) > cdReadTime * 4 ? cdReadTime * 25 : 0;
+       seekTime += pausePenalty;
+
+       seekTime = MIN_VALUE(seekTime, PSXCLK * 2 / 3);
        CDR_LOG("seek: %.2f %.2f\n", (float)seekTime / PSXCLK, (float)seekTime / cdReadTime);
        return seekTime;
 }
 
+static u32 cdrAlignTimingHack(u32 cycles)
+{
+       /*
+        * timing hack for T'ai Fu - Wrath of the Tiger:
+        * The game has a bug where it issues some cdc commands from a low priority
+        * vint handler, however there is a higher priority default bios handler
+        * that acks the vint irq and returns, so game's handler is not reached
+        * (see bios irq handler chains at e004 and the game's irq handling func
+        * at 80036810). For the game to work, vint has to arrive after the bios
+        * vint handler rejects some other irq (of which only cd and rcnt2 are
+        * active), but before the game's handler loop reads I_STAT. The time
+        * window for this is quite small (~1k cycles of so). Apparently this
+        * somehow happens naturally on the real hardware.
+        *
+        * Note: always enforcing this breaks other games like Crash PAL version
+        * (inputs get dropped because bios handler doesn't see interrupts).
+        */
+       u32 vint_rel;
+       if (psxRegs.cycle - rcnts[3].cycleStart > 250000)
+               return cycles;
+       vint_rel = rcnts[3].cycleStart + 63000 - psxRegs.cycle;
+       vint_rel += PSXCLK / 60;
+       while ((s32)(vint_rel - cycles) < 0)
+               vint_rel += PSXCLK / 60;
+       return vint_rel;
+}
+
 static void cdrUpdateTransferBuf(const u8 *buf);
 static void cdrReadInterrupt(void);
 static void cdrPrepCdda(s16 *buf, int samples);
 static void cdrAttenuate(s16 *buf, int samples, int stereo);
 
+static void msfiAdd(u8 *msfi, u32 count)
+{
+       assert(count < 75);
+       msfi[2] += count;
+       if (msfi[2] >= 75) {
+               msfi[2] -= 75;
+               msfi[1]++;
+               if (msfi[1] == 60) {
+                       msfi[1] = 0;
+                       msfi[0]++;
+               }
+       }
+}
+
 void cdrPlayReadInterrupt(void)
 {
+       cdr.LastReadCycles = psxRegs.cycle;
+
        if (cdr.Reading) {
                cdrReadInterrupt();
                return;
@@ -614,15 +665,7 @@ void cdrPlayReadInterrupt(void)
                cdr.FirstSector = 0;
        }
 
-       cdr.SetSectorPlay[2]++;
-       if (cdr.SetSectorPlay[2] == 75) {
-               cdr.SetSectorPlay[2] = 0;
-               cdr.SetSectorPlay[1]++;
-               if (cdr.SetSectorPlay[1] == 60) {
-                       cdr.SetSectorPlay[1] = 0;
-                       cdr.SetSectorPlay[0]++;
-               }
-       }
+       msfiAdd(cdr.SetSectorPlay, 1);
 
        // update for CdlGetlocP/autopause
        generate_subq(cdr.SetSectorPlay);
@@ -636,7 +679,7 @@ void cdrPlayReadInterrupt(void)
 void cdrInterrupt(void) {
        int start_rotating = 0;
        int error = 0;
-       unsigned int seekTime = 0;
+       u32 cycles, seekTime = 0;
        u32 second_resp_time = 0;
        const void *buf;
        u8 ParamC;
@@ -647,15 +690,16 @@ void cdrInterrupt(void) {
        int i;
 
        if (cdr.Stat) {
-               CDR_LOG_I("%u cdrom: cmd %02x with irqstat %x\n",
-                       psxRegs.cycle, cdr.CmdInProgress, cdr.Stat);
+               CDR_LOG_I("cmd %02x with irqstat %x\n",
+                       cdr.CmdInProgress, cdr.Stat);
                return;
        }
        if (cdr.Irq1Pending) {
                // hand out the "newest" sector, according to nocash
                cdrUpdateTransferBuf(CDR_getBuffer());
-               CDR_LOG_I("cdrom: %x:%02x:%02x loaded on ack\n",
-                       cdr.Transfer[0], cdr.Transfer[1], cdr.Transfer[2]);
+               CDR_LOG_I("%x:%02x:%02x loaded on ack, cmd=%02x res=%02x\n",
+                       cdr.Transfer[0], cdr.Transfer[1], cdr.Transfer[2],
+                       cdr.CmdInProgress, cdr.Irq1Pending);
                SetResultSize(1);
                cdr.Result[0] = cdr.Irq1Pending;
                cdr.Stat = (cdr.Irq1Pending & STATUS_ERROR) ? DiskError : DataReady;
@@ -712,6 +756,8 @@ void cdrInterrupt(void) {
                        if (((cdr.Param[0] & 0x0F) > 0x09) || (cdr.Param[0] > 0x99) || ((cdr.Param[1] & 0x0F) > 0x09) || (cdr.Param[1] >= 0x60) || ((cdr.Param[2] & 0x0F) > 0x09) || (cdr.Param[2] >= 0x75))
                        {
                                CDR_LOG_I("Invalid/out of range seek to %02X:%02X:%02X\n", cdr.Param[0], cdr.Param[1], cdr.Param[2]);
+                               if (++cdr.errorRetryhack > 100)
+                                       break;
                                error = ERROR_INVALIDARG;
                                goto set_error;
                        }
@@ -722,6 +768,7 @@ void cdrInterrupt(void) {
                                memcpy(cdr.SetSector, set_loc, 3);
                                cdr.SetSector[3] = 0;
                                cdr.SetlocPending = 1;
+                               cdr.errorRetryhack = 0;
                        }
                        break;
 
@@ -772,10 +819,12 @@ void cdrInterrupt(void) {
                        - plays tracks without retry play
                        */
                        Find_CurTrack(cdr.SetSectorPlay);
-                       ReadTrack(cdr.SetSectorPlay);
+                       generate_subq(cdr.SetSectorPlay);
                        cdr.LocL[0] = LOCL_INVALID;
+                       cdr.SubqForwardSectors = 1;
                        cdr.TrackChanged = FALSE;
                        cdr.FirstSector = 1;
+                       cdr.ReportDelay = 60;
 
                        if (!Config.Cdda)
                                CDR_play(cdr.SetSectorPlay);
@@ -870,7 +919,7 @@ void cdrInterrupt(void) {
                        }
                        else
                        {
-                               second_resp_time = (((cdr.Mode & MODE_SPEED) ? 2 : 1) * 1000000);
+                               second_resp_time = (((cdr.Mode & MODE_SPEED) ? 1 : 2) * 1097107);
                        }
                        SetPlaySeekRead(cdr.StatP, 0);
                        break;
@@ -886,7 +935,7 @@ void cdrInterrupt(void) {
                        SetPlaySeekRead(cdr.StatP, 0);
                        cdr.LocL[0] = LOCL_INVALID;
                        cdr.Muted = FALSE;
-                       cdr.Mode = 0x20; /* This fixes This is Football 2, Pooh's Party lockups */
+                       cdr.Mode = MODE_SIZE_2340; /* This fixes This is Football 2, Pooh's Party lockups */
                        second_resp_time = not_ready ? 70000 : 4100000;
                        start_rotating = 1;
                        break;
@@ -1013,6 +1062,7 @@ void cdrInterrupt(void) {
                        read_ok = ReadTrack(cdr.SetSectorPlay);
                        if (read_ok && (buf = CDR_getBuffer()))
                                memcpy(cdr.LocL, buf, 8);
+                       UpdateSubq(cdr.SetSectorPlay);
                        cdr.TrackChanged = FALSE;
                        break;
 
@@ -1112,10 +1162,15 @@ void cdrInterrupt(void) {
 
                        // Fighting Force 2 - update subq time immediately
                        // - fixes new game
-                       ReadTrack(cdr.SetSectorPlay);
+                       UpdateSubq(cdr.SetSectorPlay);
                        cdr.LocL[0] = LOCL_INVALID;
+                       cdr.SubqForwardSectors = 1;
 
-                       CDRPLAYREAD_INT(((cdr.Mode & 0x80) ? (cdReadTime) : cdReadTime * 2) + seekTime, 1);
+                       cycles = (cdr.Mode & MODE_SPEED) ? cdReadTime : cdReadTime * 2;
+                       cycles += seekTime;
+                       if (Config.hacks.cdr_read_timing)
+                               cycles = cdrAlignTimingHack(cycles);
+                       CDRPLAYREAD_INT(cycles, 1);
 
                        SetPlaySeekRead(cdr.StatP, STATUS_SEEK);
                        start_rotating = 1;
@@ -1127,7 +1182,7 @@ void cdrInterrupt(void) {
                        // FALLTHROUGH
 
                set_error:
-                       CDR_LOG_I("cdrom: cmd %02x error %02x\n", Cmd, error);
+                       CDR_LOG_I("cmd %02x error %02x\n", Cmd, error);
                        SetResultSize(2);
                        cdr.Result[0] = cdr.StatP | STATUS_ERROR;
                        cdr.Result[1] = not_ready ? ERROR_NOTREADY : error;
@@ -1146,8 +1201,7 @@ void cdrInterrupt(void) {
        }
        else if (cdr.Cmd && cdr.Cmd != (Cmd & 0xff)) {
                cdr.CmdInProgress = cdr.Cmd;
-               CDR_LOG_I("%u cdrom: cmd %02x came before %02x finished\n",
-                       psxRegs.cycle, cdr.Cmd, Cmd);
+               CDR_LOG_I("cmd %02x came before %02x finished\n", cdr.Cmd, Cmd);
        }
 
        setIrq(Cmd);
@@ -1215,7 +1269,7 @@ static void cdrAttenuate(s16 *buf, int samples, int stereo)
 static void cdrReadInterruptSetResult(unsigned char result)
 {
        if (cdr.Stat) {
-               CDR_LOG_I("cdrom: %d:%02d:%02d irq miss, cmd=%02x irqstat=%02x\n",
+               CDR_LOG_I("%d:%02d:%02d irq miss, cmd=%02x irqstat=%02x\n",
                        cdr.SetSectorPlay[0], cdr.SetSectorPlay[1], cdr.SetSectorPlay[2],
                        cdr.CmdInProgress, cdr.Stat);
                cdr.Irq1Pending = result;
@@ -1235,14 +1289,25 @@ static void cdrUpdateTransferBuf(const u8 *buf)
        CheckPPFCache(cdr.Transfer, cdr.Prev[0], cdr.Prev[1], cdr.Prev[2]);
        CDR_LOG("cdr.Transfer %x:%x:%x\n", cdr.Transfer[0], cdr.Transfer[1], cdr.Transfer[2]);
        if (cdr.FifoOffset < 2048 + 12)
-               CDR_LOG("cdrom: FifoOffset(1) %d/%d\n", cdr.FifoOffset, cdr.FifoSize);
+               CDR_LOG("FifoOffset(1) %d/%d\n", cdr.FifoOffset, cdr.FifoSize);
 }
 
 static void cdrReadInterrupt(void)
 {
        u8 *buf = NULL, *hdr;
+       u8 subqPos[3];
        int read_ok;
 
+       memcpy(subqPos, cdr.SetSectorPlay, sizeof(subqPos));
+       msfiAdd(subqPos, cdr.SubqForwardSectors);
+       UpdateSubq(subqPos);
+       if (cdr.SubqForwardSectors < SUBQ_FORWARD_SECTORS) {
+               cdr.SubqForwardSectors++;
+               CDRPLAYREAD_INT((cdr.Mode & MODE_SPEED) ? (cdReadTime / 2) : cdReadTime, 0);
+               return;
+       }
+
+       // note: CdlGetlocL should work as soon as STATUS_READ is indicated
        SetPlaySeekRead(cdr.StatP, STATUS_READ | STATUS_ROTATING);
 
        read_ok = ReadTrack(cdr.SetSectorPlay);
@@ -1253,13 +1318,12 @@ static void cdrReadInterrupt(void)
 
        if (!read_ok) {
                CDR_LOG_I("cdrReadInterrupt() Log: err\n");
-               memset(cdr.Transfer, 0, DATA_SIZE);
                cdrReadInterruptSetResult(cdr.StatP | STATUS_ERROR);
                return;
        }
        memcpy(cdr.LocL, buf, 8);
 
-       if (!cdr.Irq1Pending)
+       if (!cdr.Stat && !cdr.Irq1Pending)
                cdrUpdateTransferBuf(buf);
 
        if ((!cdr.Muted) && (cdr.Mode & MODE_STRSND) && (!Config.Xa) && (cdr.FirstSector != -1)) { // CD-XA
@@ -1295,20 +1359,7 @@ static void cdrReadInterrupt(void)
        if (!(cdr.Mode & MODE_STRSND) || !(buf[4+2] & 0x4))
                cdrReadInterruptSetResult(cdr.StatP);
 
-       cdr.SetSectorPlay[2]++;
-       if (cdr.SetSectorPlay[2] == 75) {
-               cdr.SetSectorPlay[2] = 0;
-               cdr.SetSectorPlay[1]++;
-               if (cdr.SetSectorPlay[1] == 60) {
-                       cdr.SetSectorPlay[1] = 0;
-                       cdr.SetSectorPlay[0]++;
-               }
-       }
-
-       if (!cdr.Irq1Pending) {
-               // update for CdlGetlocP
-               ReadTrack(cdr.SetSectorPlay);
-       }
+       msfiAdd(cdr.SetSectorPlay, 1);
 
        CDRPLAYREAD_INT((cdr.Mode & MODE_SPEED) ? (cdReadTime / 2) : cdReadTime, 0);
 }
@@ -1375,7 +1426,7 @@ void cdrWrite1(unsigned char rt) {
        }
 
 #ifdef CDR_LOG_CMD_IRQ
-       SysPrintf("%u cdrom: CD1 write: %x (%s)", psxRegs.cycle, rt, CmdName[rt]);
+       CDR_LOG_I("CD1 write: %x (%s)", rt, CmdName[rt]);
        if (cdr.ParamC) {
                int i;
                SysPrintf(" Param[%d] = {", cdr.ParamC);
@@ -1396,8 +1447,8 @@ void cdrWrite1(unsigned char rt) {
                CDR_INT(5000);
        }
        else {
-               CDR_LOG_I("%u cdrom: cmd while busy: %02x, prev %02x, busy %02x\n",
-                       psxRegs.cycle, rt, cdr.Cmd, cdr.CmdInProgress);
+               CDR_LOG_I("cmd while busy: %02x, prev %02x, busy %02x\n",
+                       rt, cdr.Cmd, cdr.CmdInProgress);
                if (cdr.CmdInProgress < 0x100) // no pending 2nd response
                        cdr.CmdInProgress = rt;
        }
@@ -1406,12 +1457,12 @@ void cdrWrite1(unsigned char rt) {
 }
 
 unsigned char cdrRead2(void) {
-       unsigned char ret = 0;
+       unsigned char ret = cdr.Transfer[0x920];
 
        if (cdr.FifoOffset < cdr.FifoSize)
                ret = cdr.Transfer[cdr.FifoOffset++];
        else
-               CDR_LOG_I("cdrom: read empty fifo (%d)\n", cdr.FifoSize);
+               CDR_LOG_I("read empty fifo (%d)\n", cdr.FifoSize);
 
        CDR_LOG_IO("cdr r2.dat: %02x\n", ret);
        return ret;
@@ -1458,14 +1509,24 @@ void cdrWrite3(unsigned char rt) {
                break; // transfer
        case 1:
                if (cdr.Stat & rt) {
+                       u32 nextCycle = psxRegs.intCycle[PSXINT_CDR].sCycle
+                               + psxRegs.intCycle[PSXINT_CDR].cycle;
+                       int pending = psxRegs.interrupt & (1 << PSXINT_CDR);
 #ifdef CDR_LOG_CMD_IRQ
-                       SysPrintf("%u cdrom: ack %02x (w %02x)\n",
-                               psxRegs.cycle, cdr.Stat & rt, rt);
+                       CDR_LOG_I("ack %02x (w=%02x p=%d,%x,%x,%d)\n", cdr.Stat & rt, rt,
+                               !!pending, cdr.CmdInProgress,
+                               cdr.Irq1Pending, nextCycle - psxRegs.cycle);
 #endif
-                       // note: Croc vs Discworld Noir
-                       if (!(psxRegs.interrupt & (1 << PSXINT_CDR)) &&
-                           (cdr.CmdInProgress || cdr.Irq1Pending))
-                               CDR_INT(850); // 711-993
+                       // note: Croc, Shadow Tower (more) vs Discworld Noir (<993)
+                       if (!pending && (cdr.CmdInProgress || cdr.Irq1Pending))
+                       {
+                               s32 c = 2048;
+                               if (cdr.CmdInProgress) {
+                                       c = 2048 - (psxRegs.cycle - nextCycle);
+                                       c = MAX_VALUE(c, 512);
+                               }
+                               CDR_INT(c);
+                       }
                }
                cdr.Stat &= ~rt;
 
@@ -1490,7 +1551,7 @@ void cdrWrite3(unsigned char rt) {
                CDR_LOG("cdrom: FifoOffset(2) %d/%d\n", cdr.FifoOffset, cdr.FifoSize);
        }
        else if (rt & 0x80) {
-               switch (cdr.Mode & 0x30) {
+               switch (cdr.Mode & (MODE_SIZE_2328|MODE_SIZE_2340)) {
                        case MODE_SIZE_2328:
                        case 0x00:
                                cdr.FifoOffset = 12;
@@ -1509,15 +1570,22 @@ void cdrWrite3(unsigned char rt) {
 }
 
 void psxDma3(u32 madr, u32 bcr, u32 chcr) {
-       u32 cdsize;
+       u32 cdsize, max_words;
        int size;
        u8 *ptr;
 
-       CDR_LOG("psxDma3() Log: *** DMA 3 *** %x addr = %x size = %x\n", chcr, madr, bcr);
+#if 0
+       CDR_LOG_I("psxDma3() Log: *** DMA 3 *** %x addr = %x size = %x", chcr, madr, bcr);
+       if (cdr.FifoOffset == 0) {
+               ptr = cdr.Transfer;
+               SysPrintf(" %02x:%02x:%02x", ptr[0], ptr[1], ptr[2]);
+       }
+       SysPrintf("\n");
+#endif
 
        switch (chcr & 0x71000000) {
                case 0x11000000:
-                       ptr = (u8 *)PSXM(madr);
+                       ptr = getDmaRam(madr, &max_words);
                        if (ptr == INVALID_PTR) {
                                CDR_LOG_I("psxDma3() Log: *** DMA 3 *** NULL Pointer!\n");
                                break;
@@ -1534,14 +1602,18 @@ void psxDma3(u32 madr, u32 bcr, u32 chcr) {
                        size = DATA_SIZE - cdr.FifoOffset;
                        if (size > cdsize)
                                size = cdsize;
+                       if (size > max_words * 4)
+                               size = max_words * 4;
                        if (size > 0)
                        {
                                memcpy(ptr, cdr.Transfer + cdr.FifoOffset, size);
                                cdr.FifoOffset += size;
-                               psxCpu->Clear(madr, size / 4);
                        }
-                       if (size < cdsize)
+                       if (size < cdsize) {
                                CDR_LOG_I("cdrom: dma3 %d/%d\n", size, cdsize);
+                               memset(ptr + size, cdr.Transfer[0x920], cdsize - size);
+                       }
+                       psxCpu->Clear(madr, cdsize / 4);
 
                        CDRDMA_INT((cdsize/4) * 24);
 
@@ -1631,8 +1703,10 @@ int cdrFreeze(void *f, int Mode) {
        if (Mode == 0) {
                getCdInfo();
 
-               cdr.FifoOffset = tmp;
-               cdr.FifoSize = (cdr.Mode & 0x20) ? 2340 : 2048 + 12;
+               cdr.FifoOffset = tmp < DATA_SIZE ? tmp : DATA_SIZE;
+               cdr.FifoSize = (cdr.Mode & MODE_SIZE_2340) ? 2340 : 2048 + 12;
+               if (cdr.SubqForwardSectors > SUBQ_FORWARD_SECTORS)
+                       cdr.SubqForwardSectors = SUBQ_FORWARD_SECTORS;
 
                // read right sub data
                tmpp[0] = btoi(cdr.Prev[0]);
@@ -1648,8 +1722,6 @@ int cdrFreeze(void *f, int Mode) {
                        Find_CurTrack(cdr.SetSectorPlay);
                        if (!Config.Cdda)
                                CDR_play(cdr.SetSectorPlay);
-                       if (psxRegs.interrupt & (1 << PSXINT_CDRPLAY_OLD))
-                               CDRPLAYREAD_INT((cdr.Mode & 0x80) ? (cdReadTime / 2) : cdReadTime, 1);
                }
 
                if ((cdr.freeze_ver & 0xffffff00) != 0x63647200) {